Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
oral melanoma is an extremely rare tumor arising from uncontrolled growth of melanocytes found in the basal layer of oral mucous membrane .
it occurs between 30 and 90 years of age , with a higher incidence in the 6th decade with a mean age of 56 years .
it is having a higher prevalence in yellows , blacks , japanese , and indians of asia due to more frequent finding of melanin pigmentation in oral mucosa of these races .
green et al . described criteria for diagnosis of primary oral melanoma which includes demonstration of melanoma in the oral mucosa , presence of junctional activity , inability to demonstrate extraoral primary melanoma .
a total of 80% to 90% of oral malignant melanoma arises in the mucosa of maxillary jaw with a majority occurring on the keratinized mucosa of hard palate and gingiva .
clinically , it is easy to diagnose them as these are pigmented ones and have irregular shape and outline .
these are mostly asymptomatic and detected only when there is ulceration or hemorrhage of the overlying epithelium
. the delayed detection may be the cause for the poor prognosis with a 5-year survival being between 15% and 38% .
the purpose of this article is to present a case of oral malignant melanoma , as well as to emphasize the necessity for early recognition and treatment of this lesion .
a 48-year - old male patient reported to the department of oral medicine and diagnosis with chief complaint of pain and swelling in the upper right gums .
the clinical examination revealed a large mass of 8  3 cm in dimension on buccal aspect of right maxillary alveolus involving marginal , attached , and interdental gingiva [ figure 1 ] .
anteriorly , it extends from the gingiva of mesial surface of 22 , to the gingiva in relation to 17 posteriorly .
13 was missing and 12 was displaced laterally ; while , 11 , 12 , and 21 exhibited mobility . primary oral malignant melanoma extending from 22 to distal aspect of 17 the palpatory findings revealed a firm consistency of lesion with mild pain .
a complete examination of the lesion was done and no other primary site of the lesion was found .
correlating all clinical features , diagnosis of primary malignant melanoma of oral cavity was made and the patient was referred for further investigations .
a computed tomography examination of neck , chest , abdomen , and bone scanning and ultrasounds of liver and kidney were normal excluding any diagnosis of distant metastasis .
an incisional biopsy was done for the lesion under local anesthesia and the specimen was sent for histopathologic examination .
the gross examination of tissue revealed a mass of 2 mm  3 mm  1 mm in size , which was black in color and firm in consistency .
the hematoxylin and eosin - stained section showed a melanin - producing tumor , consisting of atypical irregularly elongated spindle and oval - shaped melanocytes , exhibiting uniformly dark , enlarged and irregular nuclei [ figure 2 ] . in the superficial layers of the tissue , a junctional nevus with pigmentation
the diagnosis of an invasive melanoma arising most likely from a pre - existing junctional nevus was made and the patient was referred to the oral and maxillofacial surgery clinic for required therapy . as per the traditional approach , partial maxillectomy of the right side was performed . to reduce the defect and to reconstruct alveolus ,
microvascular fibula flap was used . the orbital floor near to maxilla was reconstructed with the help of premolded titanium mesh .
the histologic examination of the specimen confirmed the initial diagnosis of an invasive melanoma of the oral mucosa .
the patient has been followed - up with no evidence of recurrence or metastasis either clinically or radiographically , 11 months after the tumor 's resection .
the hematoxylin and eosin  stained section shows melanoma with invasive pattern showing large cells with pleomorphic vesicular nucleus and brown pigment ( 40 ) the hematoxylin and eosin  stained section shows stratified squamous keratinized epithelium with in situmelanotic pigment growth ( 10 )
it has no known predisposing factors and is difficult to diagnose and manage . differentiating it from a metastatic melanoma is often challenging .
the first symptoms of oral melanoma described by berthelsen were those of asymptomatic swelling and occasional bleeding , where he found that only 2 ( 14% ) patients had a pain .
because most of the melanomas are painless in their early stages , the diagnosis is often unfortunately delayed until symptoms resulting from ulceration , growth , or bleeding are noted .
the pain may be the later manifestation in melanoma as in our case that again could cause delay in seeking treatment . on gross appearance ,
the tumors on the palate are usually flat , with a varying degree of thickness .
microscopically , the tumor cells present themselves as densely packed , large epithelioid cells with eosinophilic cytoplasm . the melanin pigment , which is located intra or extracellularly , may be abundant , but may be sparse or even absent at the light microscopic level . the prognostic value of various levels of invasion , as established in the clark 's classification , does not apply for mucosal melanoma because of the absence of histologic landmarks , which are analogous to the papillary and reticular dermis . the staging systems that are applied to cutaneous melanoma are not applicable to mucosal melanomas . the american joint committee on cancer
the generally followed guideline is a clinical classification stage i  clinically localized disease , stage ii  regional lymph node disease , and stage iii - distant disease .
the tumor thickness is a reliable prognostic indicator for survival . in this case , the patient was in stage i. westbury describes a clinical classification as follows : 1only primary tumor present , and 2metastasis present , 2a  adjacent skin involved , 2b  adjacent lymph nodes involved , and 2ab  adjacent skin and lymph nodes involved .
thus , according to these systems specification , our patient was in stage i. the etiology of malignant melanoma is essentially unknown
. tobacco use and chronic irritation from ill - fitting dentures have been considered as possible risk factors , but the evidence is weak .
the cause could also be related to our patient as he was having the history of smoking from last 15 years .
but most of the malignant melanomas arise de novo , from apparently normal mucosa , and about 30% are preceded by oral pigmentations for several months or even years .
some melanoma - associated antigens become expressed during transformation process from a benign melanocytic nevus to melanoma ; the majorities of these are related to the melanin production process and most are hla restricted .
a recent study demonstrates that the loss of heterozygosity at 12p13 and p27kip1 protein expression contributes to melanoma progression .
cytogenetic analysis and evaluation of melanocyte - specific gene-1 ( msg-1 ) appears to be very helpful for understanding the pathogenesis of oral malignant melanoma .
the current guidelines for the surgical management of primary cutaneous melanoma recommend a diagnostic excisional biopsy of the lesion followed by a wide local excision where the diagnosis is proved .
however , in oral cavity , the size of the lesion or anatomic limitations , particularly the presence of teeth , may preclude the taking of excisional biopsy .
younes et al . proposed to take an excisional biopsy with a 12 mm margin for small lesions in amenable locations , but incisional biopsy , through the thickest or the most suspicious part of the tumor , in case of a large lesion or a location in sites where an excisional procedure would involve extensive and militating surgery .
usually oral malignant melanoma can be diagnosed with confidence on hematoxylin and eosin  stained sections .
if pigment is completely absent ( amelanotic melanoma ) , immunohistochemical stains are of significant help .
useful markers include s-100 protein , gp 100 ( hmb-45 ) , and mart-1 ( melan - a ) .
it has always been suggested that cutting into malignant neoplasm during incisional biopsy could result in accidental dissemination of malignant cells within adjacent tissues or blood or lymphatic stream with subsequent risk of local recurrence or regional or distant metastasis .
did find a somewhat reduced survival rate in patients with melanoma who had incisional biopsies but against the studies done by lederman and sober where they found no correlation in patient 's prognosis with incisional and excisional biopsies .
distant metastasis to the lungs , brain , liver , and bones are frequently observed .
the treatment of oral malignant melanoma is still controversial and there is no census regarding the best therapeutic approach .
data from several studies indicate radical resection of the primary as the treatment of choice .
regression in melanoma is a well - recognized phenomenon and may account for many of the cases of metastatic melanoma with occult primaries . partial regression of melanoma is relatively common , but complete regression is quite rare and relatively few cases are well documented .
a further feature of regression is its association with poor rather than a good prognosis .
the rather nonspecific features of regressed melanoma ( apparently inflammatory nodules , depigmented patches , and flat or slightly depressed scars ) are easily missed or discounted unless the patient had noticed the regression . from the prognostic point of view , clinical stage at presentation is probably the most important factor in determining the outcome .
it has been found by liu et al . that thickness of the tumor , cervical lymph node metastasis , presence or absence of ulceration , and the anatomic sites are all independent risk factors .
it has been calculated that nodal metastasis reduces the mean survival time from 46 to 18 months .
furthermore , a tumor thickness greater than 5 mm , presence of vascular invasion , necrosis , polymorphous tumor cell morphology , and inability to properly resect the lesion with negative margins have been associated with poor survival in patients with primary melanomas of head and neck region .
despite the improvement of surgical techniques and the introduction of new chemotherapeutic agents , prognosis of this malignancy remains poor .
the generally advanced stage of the tumor at initial diagnosis leads to a poorer survival of patients with mucosal melanomas as compared with patients with cutaneous melanomas and presence of vertical growth phase are associated with median survival rate .
analysis of published cases and recognition of new ones may be helpful in establishing definite classification and proposing clinical features that would facilitate its early diagnosis as a prerequisite for timely treatment and better prognosis of this rare pathology .

Answer:
primary oral melanoma is a rare neoplasm of melanocytic origin , accounting for 0.5% of all oral malignancies .
 the  chameleonic  presentation of a mainly asymptomatic condition , rarity of this lesion , poor prognosis , and the necessity of a highly specialized treatment are factors that should be seriously considered by the involved health provider .
 here is a case report presenting a malignant melanoma of oral mucosa in 48-year - old male patient on maxillary gingiva .
 the lesion was removed by partial maxillectomy and patient is disease free after 11 months of regular followup .
 this case provides an example of how dental clinicians play a major role in the identification of pigmented lesions of oral cavity and also emphasize on the fact that any pigmented lesion detected in the oral cavity may exhibit potential growth and should be submitted to biopsy to exclude malignancy .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
isolated involvement of the appendix in crohn 's disease is reported to be 0.2% to 1.8% , and is usually associated with ileocaecal crohn 's disease in 25% of ileal and 50% of caecal disease .
while appendicitis in a patient who was previously diagnosed to have ileocaecal crohn 's may be managed with appendicectomy and ileocaecal resection , appendicectomy alone when performed for appendicitis in a patient with unsuspected ileocaecal crohn 's disease could lead to postoperative complications including enterocutaneous fistula .
a young female patient who underwent appendicectomy elsewhere for acute appendicitis presented to us with a persistent enterocutaneous fistula of 6 weeks duration .
she had complained of general ill health and occasional altered bowel habits for 6 months prior to the acute appendicitis presentation .
our investigations , including a ct scan , suggested the possibility of ileocaecal crohn 's disease .
she underwent excision of the enterocutaneous fistula and ileocaecal resection , and histopathology of the resected specimen confirmed crohn 's disease . in the postoperative period she received mesasalazine .
when last seen 2 years later during her regular follow - up , she was found to be in good health .
the possibility of ileocaecal crohn 's disease should be considered in patients presenting with unexplained postoperative enterocutaneous fistula following appendicectomy .
a high index of clinical suspicion is required to make a prompt diagnosis and institute appropriate further treatment in form of ileocaecal resection .
crohn 's disease is a chronic inflammatory condition that may involve the entire gi tract .
histological features include granuloma , lymphoid aggregates , fissures and ulcers extending into muscularis propria , and transmural inflammation .
crohn 's disease has been reported to be the cause of acute appendicitis in 0.2% to 1.8% of all the appendicectomies in some series .
operations described in the literature for crohn 's disease of the appendix include appendicectomy with caecectomy and ileocaecal resection .
however , patients who undergo appendectomy alone are at the risk of complications including enterocutaneous fistula in 34% to 58% of the cases
a 24-year - old unmarried female patient presented to us with a persistent fistula in the right iliac fossa following an appendicectomy done in another hospital 6 weeks previously . on further questioning , she informed us that she had presented to this hospital with a 2-week history of abdominal pain , confined to the right lower abdomen .
she complained of general ill health and occasional altered bowel habits for 6 months prior to this acute episode .
an enquiry with the doctors who had initially seen her revealed that at the time of presentation for acute appendicitis she was quite unwell with fever , tachycardia , and dehydration .
her abdomen was tender all over with guarding , more pronounced over the right lower half .
an x - ray of her abdomen showed a few fluid levels and an ultrasound scan revealed free fluid in the abdomen with an associated right iliac fossa mass .
a diagnosis of pelvic peritonitis secondary to acute appendicitis was made by the physicians , and she was taken up for surgery after adequate resuscitation .
there was pus in the abdomen with an appendicular mass , and the appendix appeared oedematous , thickened , and congested .
the abdomen was closed after placing a drain , which was removed on the 3 post - operative day . in spite of antibiotic administration
she was managed conservatively with antibiotics and anti - inflammatory medication and eventually improved , except for a persistent purulent discharge from the wound .
she then decided to seek our opinion and was admitted under our care for further investigation and management .
the appendicular histopathology was retrieved from the previous hospital and revealed transmural inflammation with granulomas suggestive of crohn 's disease .
a computerized tomography ( ct ) scan of the abdomen carried out in our hospital showed pericaecal collection with an inflammatory mass in front of the caecum ( fig .
the abdomen was surgically explored through the previous incision after excising the fistula leading into the caecum . an inflammatory mass associated with the caecum was noted .
the appendicular stump had not healed , and was draining into a cavity which was communicating with the wound , indicating a complex enterocutaneous fistula . a limited right hemicolectomy was carried out and continuity established with a primary anastomosis of macroscopically - appearing healthy bowel of the ascending colon and terminal ileum .
a specimen of the resected caecum revealed the cobblestone appearance of the mucosa , strongly suggesting the possibility of underlying caecal crohn 's disease ( fig .
the histology was reported as inflammatory bowel disease ( ibd ) consistent with crohn 's disease ( fig .
she was referred to a gastroenterologist and was being treated with mesasalazine and a regular annual colonoscopy .
when last seen at two years post - surgery she continued to remain in good health . limited right hemicolectomy specimen showing the cobble stone appearance of the mucosa typical of crohn 's disease .
crohn 's disease may involve the appendix by extension from the terminal ileum or the caecum and present as an acute or sub - acute appendicitis[15 ] .
crohn 's disease limited to the appendix usually affects young adults in their 20s and 30s , although it is not limited to this age group and can occur at any age .
the clinical presentation is variable , with acute right iliac fossa pain suggestive of acute appendicitis in about 85% of patients , and chronic pain and a palpable mass in the right iliac fossa in about 25% of patients .
when the preoperative diagnosis is acute appendicitis , crohn 's disease should be suspected when an atypical or protracted clinical course is present in a patient prior to the appendicitis , particularly in areas where crohn 's disease is prevalent .
crohn 's disease is diagnosed by a combination of clinical manifestations and radiological findings including barium studies , showing string strictures , fissures , and fistula in the ileum and caecum .
recently , gray scale sonography and color doppler - flow features have been used in diagnosing crohn 's disease . when the disease is located atypically in the appendix ,
macroscopically , the appendix will be seen to be enlarged , swollen and adherent to the surrounding structures , these findings being secondary to chronic inflammation .
histologically , the disease is characterized by transmural inflammation with thickening of the appendiceal wall , epitheloid granulomas , lymphoid aggregates , and mucosal ulceration .
other histological features are multinucleated giant langherhan 's cells , crypt abscess , neural hyperplasia and lymphangiectasia .
differential diagnosis includes the presence of foreign bodies and diverticulitis of the appendix , which also give rise to chronic granulomatous inflammation with induration and fibrosis of the appendiceal wall , and granulomatous disease of unknown aetiology such as appendiceal sarcoidosis , which is rare and often accompanies systemic disease .
differential diagnosis should also include infectious diseases such as tuberculosis , actinomycosis and yersenia infection .
a rare fungal infection such as histoplasmosis or blastomycosis , or a parasitic infestation such as schistosomiasis or enterobius vermicularis infestation can elicit an appendiceal granulomatous reaction .
the diagnostic difficulty arises when a patient undergoes an appendicectomy for suspected acute appendicitis and the surgeon unexpectedly encounters ileocaecal pathology whose nature is difficult to ascertain in an emergency situation . in view of this , a definitive treatment in the form of ileocaecal resection for conditions like crohn 's disease may be difficult to carry out . while a frozen section may be helpful to differentiate some of these conditions it may not always be feasible in an emergency situation . if crohn 's disease of the appendix is suspected and is limited to the appendix then appendicectomy alone is a routine surgical procedure with very low intraoperative or postoperative mortality and a low rate of fistula formation.the postoperative enterocutaneous fistula incidence rate in crohn 's disease restricted to appendix alone has been reported to be 3.5% , whereas in patients with crohn 's disease of the ileocaecal segment , as in our patient , the postoperative enterocutaneous rate rises to 34% to 58% .
weston et al reported that the majority of the patients whose first presentation of crohn 's disease simulates appendicitis and who undergo appendicectomy alone leaving the ileocaecal segment in place to be treated medically , returned postoperatively within 3 years with symptoms . a significant percentage ( 38% ) of these patients returned within one year and most of them ( 77% ) were frequently ill with their disease in the interim period .
patients who had an ileocolic resection at the time of the initial operation did not require early reoperation , did not develop short bowel syndrome , and did not have significant postoperative complications .
in the postoperative period these patients receive medical therapy to keep the disease quiescent such as salazopyrine , 5-asa , prednisilone , and azothioprine.crohn's disease - related fistula have also been treated with infliximab with some success . despite improvements in medical therapy , between 70% to 90% of the patients with crohn 's disease will eventually require surgical intervention , and approximately half of these will require additional operations . because of the high risk of reoperations and a relatively young age at the time of first operation , a minimally invasive approach has recently been used to carry out the ileocolic resections .
a recent meta - analysis of laparoscopic ileocolic resection has revealed a shorter hospital stay compared to open resection , while the morbidity rates were equal and conversion rates were acceptable .
the average interval between surgery and recurrence after appendicectomy for crohn 's disease of the appendix is 4 years , after which some claim the recurrence rate to be almost nil .
however , others have reported a recurrence rate of 10% over an 8-year follow - up and is much higher in patients with crohn 's disease of the appendix associated with ileocaecal crohn 's disease .
most authors recommend periodic surveillance visits with radiological and endoscopic examination of the small intestinal and colon for a period of at least 3 years to promptly detect recurrence .
however , others claim that patients with crohn 's disease should be followed for 10 years , and if disease free by then are considered cured .
crohn 's disease of the appendix is usually associated with crohn 's disease of the ileum and caecum .
appendicectomy will suffice in those who present subacutely , are diagnosed preoperatively by clinical signs , and radiographic evidence shows that the disease is restricted to the appendix alone .
however , in the presence of ileocaecal involvement , resection of the ileocaecal segment may be required to prevent postoperative complications of enterocutaneous fistula . while patients who develop enterocutaneous fistula post - appendicectomy in an unsuspected crohn 's disease case have been treated with infliximab with some success , the majority of the patients required ileocaecal resection . moreover ,

Answer:
context : isolated involvement of the appendix in crohn 's disease is reported to be 0.2% to 1.8% , and is usually associated with ileocaecal crohn 's disease in 25% of ileal and 50% of caecal disease .
 while appendicitis in a patient who was previously diagnosed to have ileocaecal crohn 's may be managed with appendicectomy and ileocaecal resection , appendicectomy alone when performed for appendicitis in a patient with unsuspected ileocaecal crohn 's disease could lead to postoperative complications including enterocutaneous fistula.case report : a young female patient who underwent appendicectomy elsewhere for acute appendicitis presented to us with a persistent enterocutaneous fistula of 6 weeks duration .
 she had complained of general ill health and occasional altered bowel habits for 6 months prior to the acute appendicitis presentation .
 our investigations , including a ct scan , suggested the possibility of ileocaecal crohn 's disease .
 she underwent excision of the enterocutaneous fistula and ileocaecal resection , and histopathology of the resected specimen confirmed crohn 's disease . in the postoperative period she received mesasalazine . when last seen 2 years later during her regular follow - up , she was found to be in good health.conclusion:the possibility of ileocaecal crohn 's disease
 should be considered in patients presenting with unexplained postoperative enterocutaneous fistula following appendicectomy .
 a high index of clinical suspicion is required to make a prompt diagnosis and institute appropriate further treatment in form of ileocaecal resection .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
testosterone is essential for the normal growth and development of the prostate gland and is also a possible risk factor for prostate cancer .
huggins and hodges 's seminal work in the 1940s first demonstrated the hormone dependence of prostate cancer , consequently establishing testosterone as a key therapeutic target for managing prostate cancer .
androgen deprivation therapy to lower the serum testosterone level remains a standard treatment for advanced disease to the present day .
isbarn et al 's recent studies , however , show a result opposite that of huggins and hodges , implying that testosterone neither increases the risk of prostate cancer nor causes cancer recurrence in men who have been treated successfully for prostate cancer .
a recent study by morote et al showed that prostate cancer risk and tumor aggressiveness are unrelated to serum testosterone .
other recent epidemiologic studies also have found no association between testosterone and prostate cancer [ 6 - 10 ] . our main objective was to analyze the relationship between serum testosterone , prostate - specific antigen ( psa ) , and prostate cancer risk in high - risk patients .
the study population consisted of 120 men with a psa level of 10 ng / ml or higher .
the data were collected from january 2008 to january 2010 . to determine the relationship between testosterone , psa , and prostate cancer risk in a high - risk group , we limited our study population to men with a psa level of 10 ng / ml or higher .
we excluded from this analysis men who were taking medications known to lower psa , such as finasteride or dutasteride .
twelve cores were obtained and two extra biopsies were taken if hypoechoic or otherwise suspicious areas were noted on ultrasound .
serum testosterone levels were measured by using a solid - phase competitive chemiluminescent enzyme immunoassay with the advia centaur immunoassay system ( bayer health care , chicago , il , usa ) .
we classified the men as hypogonadal if their serum testosterone level was < 300 ng / dl , according to the criteria used by rhoden et al . for possible correlation between serum testosterone , psa , and prostate cancer , we included age , psa density ( psad ) , prostate volume , and gleason score for patients with prostate cancer .
statistical analysis was performed by using the student 's t - test , the pearson correlation test , simple linear regression , and binary logistic regression . odds ratios with 95% confidence intervals ( cis ) for psa , psad , serum testosterone , and age were determined to predict prostate cancer risk .
all data are presented as the mean2 sd to define and characterize quantitative variables and as percentages to characterize qualitative variables ; we considered a p - value<0.05 to be statistically significant .
out of 120 patients , the samples of 85 ( 70.1% ) patients were diagnosed as benign and those of 35 ( 29.2% ) patients were diagnosed as being prostate cancer .
there was no significant difference in the patient 's average age , psa , prostate volume , or testosterone between patients without and those with prostate cancer .
only psad differed significantly between the two groups ( t - test , p=0.012 ) ( table 1 ) .
hypogonadal and eugonadal men did not differ significantly in cancer detection rate ( 30.2% vs. 32.0% , respectively ) .
the testosterone level did not differ significantly between patients without and those with prostate cancer in either hypogonadal ( 248.1650.41 ng / dl vs. 251.3543.61 ng / dl , respectively ) or eugonadal ( 501.52137.06 ng / dl vs. 506.22126.40 ng / dl , respectively ) men ( t - test , p>0.05 ) .
testosterone was unrelated to age , psa , psad , or prostate volume in both men without and those with prostate cancer , and prostate cancer aggressiveness also was unrelated to serum testosterone in prostate cancer patients ( p>0.05 ) ( table 2 ) .
the binary logistic regression also confirmed that none of the variables used in this study was an independent predictor of prostate cancer risk for men with a psa level > 10 ng / ml ( p>0.05 ) ( table 3 ) .
further evaluation with simple linear regression confirmed that testosterone and psa did not show any correlation ( p>0.05 ) ( fig .
when we divided the patients into 11 groups according to their testosterone level , within a 150 ng / dl range , prostate cancer prevalence did not change as the testosterone level increased ( p>0.05 ) ( table 4 ) .
in men , the leydig cells in the testes produce approximately 90% of testosterone ; the adrenal glands produce the rest .
testosterone plays a key role in the development of male reproductive tissues such as the testes and prostate gland . under testosterone influence , the prostate gland experiences two main growth periods .
the first occurs early in puberty , when the prostate doubles in size . at around age 25 ,
when the prostate is growing , testosterone is converted into dihydrotestosterone ( dht ) , which is the androgen receptor 's major activator .
after dth binds to androgen receptors , it translocates to the nucleus , where it mediates the transcriptional activation of target genes .
these androgen - stimulated changes in gene expression promote cellular growth , which often results in benign prostatic hyperplasia in elderly men .
long - term cessation of the prostate 's exposure to androgen appears to protect against the development of cancer , but no dose - response relationship between testosterone level and cancer risk has been established .
the prostate cancer risk for men with a testosterone concentration in the normal range remains unclear .
recent chemopreventive trials with 5-alpha - reductase inhibitors show the role of testosterone in prostate cancer development .
finasteride reduced the risk of prostate cancer by 24.8% compared with a placebo in healthy men .
recently , the reduce study showed that dutasteride also reduced the risk of prostate cancer by 23% compared with a placebo in healthy men .
huggins and hodges first showed the effect of testosterone on prostate cancer patients in 1941 .
they showed the hormonal responsiveness of prostate cancer by reporting that markedly reducing the testosterone level by castration and estrogen treatment caused metastatic prostate cancer to regress , and injecting testosterone caused prostate cancer to grow . in 1995
wu et al found that the distribution of dihydrotestosterone - to - testosterone ratios parallels both the incidence of and mortality from prostate cancer .
the demonstration that androgen suppression effectively treats advanced prostate cancer , and the fact that elevated serum androgen levels might predispose people to prostate cancer , have attracted persistent interest .
however , a recent study refuted any connection between elevated testosterone levels and increased prostate cancer risk .
endogenous hormones and prostate cancer collaborative group et al meta - analyzed the serum concentrations of sex hormones from subjects in 18 prospective studies that included 3,886 men with incident prostate cancer and 6,438 control subjects .
they concluded that endogenous hormones , including testosterone , were not associated with prostate cancer .
morote et al recently conducted another study of 478 patients , all of whom were assessed by trus - guided prostate biopsy because of an abnormal digital rectal examination , psa > 4 ng / ml , or both .
they found no difference in serum testosterone level between patients with and those without prostate cancer and concluded that the serum testosterone level was not associated with prostate cancer risk or aggressiveness .
an animal study by morgentaler and traish showed that beyond a certain serum testosterone concentration , androgens have a limited ability to stimulate prostate cancer growth .
subsequent increases in serum testosterone levels beyond that concentration did not stimulate the prostate because the binding capacity of the intra - prostatic androgen receptors had been saturated .
our results are similar to those of the above studies even though we limited our study population to patients with psa > 10 ng / ml . we found that the serum testosterone level at the time of diagnosis was unrelated to psa and prostate cancer risk and aggressiveness in both hypogonadal and eugonadal patients .
ideas about the interaction between testosterone and prostate cancer have changed considerably over the past decade . like our study , most recent epidemiologic studies have found no association between testosterone and prostate cancer [ 6 - 10 ] .
a few studies published during the past decade contrast with our results , however , and show that low testosterone levels seem to be related to an increased risk of prostate cancer and tumor aggressiveness , such as a high gleason score [ 23 - 28 ] . in our study , we compared age , psa , prostate volume , and psad with testosterone .
only a known prostate cancer predictor , psad , showed a significant difference between patients with and those without prostate cancer , even in high - risk patients with a psa level of 10 ng / ml or higher .
patients without prostate cancer had relatively lower psa and larger prostates than did patients with prostate cancer .
however , our binary logistic regression showed that psad was unsuitable as an independent predictor of prostate cancer risk in men with a psa level of 10 ng / ml or higher .
we measured the serum testosterone level in the patients only once , before their biopsy was done .
second , we checked only their total testosterone level and were unable to check their free testosterone level .
, the present study found that the serum testosterone level at the time of diagnosis was unrelated to psa and prostate cancer risk and aggressiveness . because testosterone levels change with age and time , a prospective study with long - term testosterone monitoring is required to find a relationship between testosterone and prostate cancer .
our results show that the serum testosterone level at the time of diagnosis was unrelated to psa and prostate cancer risk and aggressiveness .
additional studies with long - term follow - up are needed to explain the possible mechanism and relationship between testosterone , prostate cancer , and psa .

Answer:
purposetestosterone is essential for the prostate gland 's normal growth and development and is also a possible risk factor for prostate cancer .
 this study 's aim was to determine the significance of serum testosterone for prostate - specific antigen ( psa ) elevation and prostate cancer prediction in high - risk men.materials and methodsthe study included 120 patients with psa > 10 ng / ml who underwent a transrectal - prostate biopsy .
 serum testosterone , prostate volume , and psa density ( psad ) were checked in all patients .
 patients were divided into two groups , patients with and those without prostate cancer ; and testosterone - related factors , prostate volume , psa , psad , age , prostate cancer prediction rate , and cancer aggressiveness were evaluated.resultsthirty-five patients ( 30.2% ) were confirmed as having prostate cancer . the average serum testosterone level in patients without and in those with prostate cancer was 452.25154.62 ng / dl and 458.10158.84 ng / dl , respectively ; average psa was 17.589.02 ng / ml and 18.626.53 ng / ml , respectively ; and average age was 69.027.52 years and 70.697.02 years , respectively ( p>0.05 ) . hypogonadal and eugonadal
 patients showed no significant difference in cancer prevalence ( 30.3% vs. 32.0% , respectively ) .
 the testosterone level did not differ significantly in patients with and those without prostate cancer in either hypogonadal or eugonadal men ( p>0.05 ) .
 serum testosterone showed no correlation with psa , psad , or age in either group ( p>0.05 ) and was unrelated to prostate cancer risk or aggressiveness ( p>0.05).conclusionsin our study 's results , serum testosterone at the time of diagnosis was unrelated to psa elevation , prostate cancer risk , and aggressiveness .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
posttraumatic avascular necrosis ( avn ) of the scaphoid is a common complication probably due to the precarious blood supply .
the rate of incidence is about 13% to 40% and almost all are seen in the proximal fragment [ 2 , 3 ] .
careful review of the literature revealed six cases of distal avn in three studies [ 4 , 5 , 6 ] .
the diagnosis of avn of the scaphoid is made by combining the mri findings with direct observation of the punctuate bleeding during the operation .
however , the diagnosis of avn is suspicious in these cases , as mri investigation had been performed in one case   and preoperative bleeding was observed in the other .
here , we report four new cases , all with the correlation of mri and punctuate bleeding .
the series consisted of four patients aged 29 , 33 , 53 and 57 years .
all had a history of scaphoid fracture following a fall on an outstretched hand 35 years ago , and all had been treated by casting before .
radiographic examination revealed suspected areas , such as sclerosis and/or cystic changes , on the distal pole of the scaphoid ( figure 1 ) and mri views were identical with avn of the distal pole , showing hyperintense changes ( figure 2 ) .

tourniquet was deflated in order to observe punctuate bleeding ; it was observed in three cases and the patients were treated by bone grafting and wire fixation ( figure 3 ) in the remaining , there was no punctuate bleeding despite drilling and the scaphoid was excised and radial advancement osteotomy ( figure 4 ) was performed .

treated by bone grafting and wire fixation .

 scaphoid was excised and radial advancement osteotomy .

all patients were evaluated by quick disabilities of shoulder , arm , and hand score 711 years after the operation by telephone interview . according to this score , 11 questions related to daily living
posttraumatic avn of the scaphoid occurs as a result of impairment of the vascular supply to the involved bone fragment .
several studies had demonstrated a strikingly poor blood supply to the proximal pole , particularly in comparison with the abundant supply to the distal two - thirds of the scaphoid [ 1 , 2 ] .
review of the literature revealed six cases in three reports [ 4 , 5 , 6 ] .
, avn in the distal fragment occurs if the volar vessel is damaged and the fracture line is distal to the line of entry of the dorsal vessels .
another explanation maybe the anomalous different vascularization of the distal pole [ 5 , 6 , 9 ] .
the diagnosis of avn of the scaphoid was made by combining the mri findings with direct observation of the punctuate bleeding during the operation .
however , there is no such approach in the previously described cases [ 4 , 5 , 6 ] . in the case of sherman et al . , mri was not available and there was no chance to observe bleeding , as the patients had refused surgical treatment .
similarly , in the case of the garg et al . , although mri suggested avn , the patient had been treated conservatively , so there was no chance for punctuate bleeding , and the fracture united .
the diagnosis is also suspicious in this case as no correlation was possible and the fracture had healed .
according to herbert , avn means irreversible necrosis or death of bone and healing is impossible .
only one case had been operated . in this case , the authors had confirmed avn by the pinning attempt that had failed .
there seems no such method for the diagnosis of avn , so the diagnosis is again in doubt . in our opinion
, all these cases should be labeled as suspected avn . in three of our cases , although preoperative mri suggested avn ( figure 2 ) , punctuate bleeding was observed during the operation and all were treated by pinning and grafting and healed uneventfully . in those cases , the appearance of avn was probably due to the normal marrow of bone that has not been established yet , but bleeding was observed due to revascularition . in the remaining case , mri suggested avn along with lack of punctuate bleeding and scaphoid was excised and radial advancement osteotomy was performed . in conclusion , all six cases reported before [ 4 , 5 , 6 ] , and three of our cases that were treated by pinning and had healed , were not real avn or the diagnosis was doubtful .
so our fourth case seems to be a unique case of distal pole avn of the scaphoid in the literature .

Answer:
abstractavascular necrosis ( avn ) of the scaphoid predominantly occurs in the proximal pole .
 review of the literature revealed only six cases and all are suspect due to the lack of either mri investigation or investigation of bleeding preoperatively .
 we report four new cases and one of them appears to be a real distal pole avn of the scaphoid in the literature .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
high resolution transmission electron microscopy and high angle annular dark - field scanning transmission electron microscopy were employed to investigate the microstructure and the epitaxial growth of the structures .
room temperature ferroelectric and ferrimagnetic domains of the heterostructures were imaged by piezoresponse force microscopy ( pfm ) and magnetic force microscopy ( mfm ) , respectively .
pfm and mfm investigations proved that the hybrid epitaxial nanostructures show ferroelectric and magnetic order at room temperature .
dielectric effects occurring after repeated switching of the polarization in large planar capacitors , comprising ferrimagnetic nife2o4 dots embedded in ferroelectric pbzr0.52ti0.48o3 matrix , were studied .
these hybrid multiferroic structures with clean and well defined epitaxial interfaces hold promise for reliable investigations of magnetoelectric coupling between the ferrimagnetic / magnetostrictive and ferroelectric / piezoelectric phases .
there is no conflict of interest in the present study for any of the authors .

Answer:
epitaxial heterostructures combining ferroelectric ( fe ) and ferromagnetic ( fim ) oxides are a possible route to explore coupling mechanisms between the two independent order parameters , polarization and magnetization of the component phases .
 we report on the fabrication and properties of arrays of hybrid epitaxial nanostructures of fim nife2o4 ( nfo ) and fe pbzr0.52ti0.48o3 or pbzr0.2ti0.8o3 , with large range order and lateral dimensions from 200 nm to 1 micron.methodsthe structures were fabricated by pulsed - laser deposition .
 high resolution transmission electron microscopy and high angle annular dark - field scanning transmission electron microscopy were employed to investigate the microstructure and the epitaxial growth of the structures .
 room temperature ferroelectric and ferrimagnetic domains of the heterostructures were imaged by piezoresponse force microscopy ( pfm ) and magnetic force microscopy ( mfm ) , respectively.resultspfm and mfm investigations proved that the hybrid epitaxial nanostructures show ferroelectric and magnetic order at room temperature .
 dielectric effects occurring after repeated switching of the polarization in large planar capacitors , comprising ferrimagnetic nife2o4 dots embedded in ferroelectric pbzr0.52ti0.48o3 matrix , were studied.conclusionthese hybrid multiferroic structures with clean and well defined epitaxial interfaces hold promise for reliable investigations of magnetoelectric coupling between the ferrimagnetic / magnetostrictive and ferroelectric / piezoelectric phases .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
the immunosuppressive receptor pd-1 and its ligand pd - l1 have been identified by dr .
tasuku honjo and his colleagues at the kyoto university as factors that
 induce programmed cell death .
since the mechanism mediated by pd-1 and its ligand was shown to be important for immune
 suppression and tolerance , it has also been reported to be involved in pathogenetic mechanisms of various diseases .

pd-1 and pd - l1 are single - pass transmembrane molecules expressed on the cell surface , which belong to the b7 family . their expression is induced by
 immune - activating stimuli and is understood as a negative feedback mechanism to suppress excessive immune reactions and let immune responses cease .
when the
 receptor pd-1 is bound by its ligand , src homology 2-domain - containing tyrosine phosphatase 2 ( shp-2 ) and shp-1 are recruited to immunoreceptor tyrosine - based
 inhibitory motif and immunoreceptor tyrosine - based switch motif in the intracellular region of pd-1 and suppress antigen receptor signaling mediators .
this process results in reduced production of cytokines , such as interferon ( ifn)- and interleukin ( il)-2 , reduced cell
 proliferation and suppressed immune cell activation . in addition to the close involvement in homeostasis of the living body as summarized above , recent studies
 have shown that immunosuppressive factors , pd-1 and pd - l1 , are also involved in immunosuppression in cases of tumors and chronic infections . while generally not
 highly expressed in normal tissues , pd - l1 is expressed at a high rate in tumor tissues in melanoma , lung cancer , colorectal cancer and ovarian cancer , and has
 been demonstrated to be involved in immune evasion by tumors . in patients with renal cell cancer and gastric cancer ,
 pd - l1 has been shown to be an important prognostic determinant ; also , the disease progression is faster , and the mortality is higher in patients with tumors
 expressing pd - l1 than in patients without detectable pd - l1 expression [ 51 , 53 ] . in
 addition , pd - l1 expression has also been reported for other tumors including breast cancer , pancreatic cancer and bladder cancer , and pd-1 expression in
 tumor - infiltrating lymphocytes has been confirmed in many types of tumors including melanoma , lung cancer and intrahepatic bile duct cancer .
these findings have
 revealed the importance of the pd-1/pd - l1 pathway as an immunosuppression mechanism in a variety of tumors . based on the series of studies on pd-1/pd - l1 in tumor
 diseases , therapeutic means targeting this pathway are being developed .
specifically , these new therapeutics are biopharmaceuticals based on anti - pd-1 antibodies ,
 anti - pd - l1 antibodies or recombinant proteins that inhibit the pd-1/pd - l1 pathway .
these biopharmaceuticals have been reported to show good anti - tumor effects
 regardless of the tumor type and are attracting growing attention as a new , promising class of anti - tumor therapy .
fully humanized anti - pd-1 and anti - pd - l1
 antibodies have already been produced and are actively tested as therapeutic agents in clinical studies ( trials ) , with good anti - tumor effects continuing to be
 reported in patients with melanoma , lung cancer , renal cell cancer and some other types of cancer . in melanoma , which has a very poor prognosis , clinical trials
 conducted in japan and the united states have reported not only the suppressed growth of cancer cells , but also complete remission in some cases . on september ,
 2014 , the anti - pd-1 antibody
was finally released by ono pharmaceutical as a new anti - tumor therapeutic agent , and it has become a pioneer
 for innovative immune checkpoint inhibitors ( ono pharmaceutical : https://www.opdivo.jp/contents/action/ ) .
this immune checkpoint - targeted immunotherapy was
 selected as  breakthrough of the year 2013  by the journal science as a global revolutionary technology . currently , merck , roche and other major pharmaceutical
 companies around the world are accelerating their efforts to develop similar antibody - based drugs ; this class of therapeutics is gaining so much momentum and
 attention that the conventional concept of anti - tumor therapy is being overturned .
the causative factors of bovine leukemia can be divided
 into viral and non - viral .
non - viral bovine leukemia is sporadic and can be subdivided into calf type , thymic type and cutaneous type involving unknown causes .
on
 the other hand , enzootic bovine leukemia , which is caused by blv , accounts for the vast majority of cases of bovine leukemia , and its prevalence continues to
 increase .
blv infections are latent in the aleukemic ( al ) state , but can emerge as persistent lymphocystosis ( pl ) with non - malignant polyclonal expansion of
 cd5 b - cells that predominantly harbor blv provirus and rarely as malignant b - cell lymphoma in various lymph nodes after long periods of latency
 .
the progression of enzootic bovine leukemia is accompanied by marked suppression of cell - mediated immunity [ 8 , 9 , 16 ] , and as the pathogenetic mechanism
 remains unknown , there are no effective vaccines or therapeutic methods available , meaning that affected animals eventually die .
bovine leukemia was designated as
 a communicable disease obligated to notify under the act on domestic animal infectious diseases control when it was revised in 1997 . in 2015 ,
2,896 cases of
 bovine leukemia were reported ( of which the largest number of 494 cases occurred in hokkaido ) , representing the disease reported in a greater number than any
 other bovine disease required to monitor by the act ( http://www.maff.go.jp/j/syouan/douei/kansi_densen/kansi_densen.html ) .
this number is 29.3-fold the number of
 cases reported in 1998 ( 96 affected animals ) , indicating that the increase has not yet been halted .
requests for urgent measures against this disease have been
 voiced very frequently by people practicing veterinary medicine and animal husbandry . however , a large - scale survey conducted by the national institute of animal
 health using specimens collected from 2009 to 2011 showed an approximate blv - positive rate of 35% , demonstrating the difficulty of implementing any project to
 select and replace infected cattle .
comparative analyses of blv - infected cattle by clinical condition have suggested that animals with a high viral load and persistent lymphocytosis are at a high
 risk of disease onset , often serving as infection sources , have a high risk of vertical transmission   and have increased levels of cd4cd25foxp3 treg cells , showing increased susceptibility
 to opportunistic infections due to transforming growth factor - beta produced by treg cells , which reduces the production of interferon - gamma and tumor necrosis
 factor - alpha by cd4 t cells and impairs cellular immunity mediated mainly by the cytotoxic activity of nk cells [ 28 , 48 ] .
moreover , the proliferative ability of lymphocytes in response to blv was also significantly reduced in
 cattle with persistent lymphocytosis , and lymphocytes were found to produce reduced levels of anti - viral cytokines , such as ifn- , il-2 and il-12 [ 13 , 18 ] . therefore , we analyzed the expression of pd-1 and its ligand , pd - l1 .
results
 showed that the pd-1 expression in cd4 and cd8 cells and the pd - l1 expression in virus - infected b cells increase as the disease
 progresses .
furthermore , pd - l1 expression negatively correlated with the ifn- expression level , an indicator of immunosuppression , while positively correlating
 with leukocyte count , virus titer and provirus level . antibodies to bovine pd-1 and pd - l1 were established , and the results from pd-1 and pd - l1 binding inhibition
 assays confirmed that they activated anti - viral immunity and that the increase in ifn- production positively correlated with the pd-1 expression rate on
 cd4 t cells . and also , recombinant bovine pd - l2 ( pd - l2-ig ) significantly enhanced ifn- production from virus antigens - stimulated pbmcs derived from
 blv - infected cattle .
interestingly , the pd - l2-ig - induced ifn- production was further enhanced by treatment with anti - bovine pd-1 antibody .
these results indicated that the pd-1/pd - l pathway constitutes a part of the immunosuppressive mechanism in bovine leukemia ( table 2table 2.change of immune inhibitory molecules in the cause of bovine leukemia virus infectionreceptor / liganduninfectedinfected(disease status)referencesalpllymphomapd-1/pd - l1///// lag-3/mhcclass ii////n.d [ 17 , 41]tim-3/gal-9///// ctla-4/cd80 , cd86/n.d/n.d/n.d/n.dn.d n.d : not demonstrated . )
we also analyzed immunosuppressive receptors other than the pd-1/pd - l1 pathway ,
 such as lymphocyte - activation gene 3 ( lag-3 ) [ 17 , 41 ] , t - cell immunoglobulin and
 mucin domain - containing protein 3 ( tim-3 ) , and cytotoxic t - lymphocyte antigen 4 ( ctla-4 ; cd152 )   expressed in antigen - specific lymphocytes and found that expression levels of lag-3 , tim-3 , ctla-4 and their ligands on lymphocytes
 increased as the disease progressed and anti - viral immunity was activated in binding inhibition assays , as was the case for pd-1 ( table 2 ) .
currently , clinical studies of these drugs are being carried out at the hokkaido university and other institutions .
although there are many diseases in cattle involving immune abnormalities ( impairments ) , the mechanisms underlying these diseases remain unknown .
our previous
 analyses have shown that immunosuppressive factors , such as pd - l1 , are also involved in immune suppression seen in diseases other than bovine leukemia , namely
 johne s disease   and bovine anaplasmosis .
furthermore , recent evidence
 suggests that immunosuppressive factors , such as pd-1 , are involved in the reduced immune function in chronic infectious diseases , such as mastitis , bovine
 mycoplasmosis and bovine tuberculosis ( manuscript in preparation ) .
our laboratory has been working on the development of a blv vaccine for many years .
it is based
 on a vaccine antigen that was found to be promising in in vitro studies . however , although we tried various procedures , the vaccine did not
 prevent infection or even disease onset despite the fact that effector cells were present in vivo ( data not shown ) .
results from the present
 analysis suggested that the virus s immune evasion mechanism for lymphocyte exhaustion might be related to the ineffectiveness of the vaccine .
future measures
 against chronic infectious diseases will require the development of a new , pre - emptive control method that targets this formidable immune evasion mechanism . to
 achieve this goal ,
results from more detailed analyses of immune exhaustion in other chronic infections are awaited . for use in humans , several immune
 checkpoint - targeting biopharmaceuticals
have been successively developed , including those described above , and they are being actively tested in clinical trials .
 in the future , it is anticipated that they will be applied to veterinary medicine and animal husbandry , including diseases in cattle .

Answer:
recently , dysfunction of antigen - specific t cells is well documented as t - cell exhaustion and has been defined by the loss of effector functions during chronic
 infections and cancer in human .
 the exhausted t cells are characterized phenotypically by the surface expression of immunoinhibitory receptors , such as
 programmed death 1 ( pd-1 ) , lymphocyte activation gene 3 ( lag-3 ) , t - cell immunoglobulin and mucin domain - containing protein 3 ( tim-3 ) and cytotoxic t - lymphocyte
 antigen 4 ( ctla-4 ) .
 however , there is still a fundamental lack of knowledge about the immunoinhibitory receptors in the fields of veterinary medicine . in
 particular , very little is known about mechanism of t cell dysfunction in chronic infection in cattle .
 recent our studies have revealed that immunoinhibitory
 molecules including pd-1/ programmed death - ligand 1 ( pd - l1 ) play critical roles in immune exhaustion and disease progression in case of bovine leukemia virus
 ( blv ) infection , johne s disease and bovine anaplasmosis .
 this review includes some recent data from us .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
as a service to our authors and readers , this journal provides supporting information supplied by the authors .
such materials are peer reviewed and may be reorganized for online delivery , but are not copyedited or typeset .
technical support issues arising from supporting information ( other than missing files ) should be addressed to the authors .

Answer:
abstracthelically chiral n , n , o , oboron chelated dipyrromethenes showed solutionphase circularly polarized luminescence ( cpl ) in the red region of the visible spectrum (
 em(max ) from 621 to 663  nm ) .
 the parent dipyrromethene is desymmetrised through o chelation of boron by the 3,5orthophenolic substituents , inducing a helical chirality in the fluorophore .
 the combination of high luminescence dissymmetry factors ( |g
 lum| up to 4.7 103 ) and fluorescence quantum yields (
 f up to 0.73 ) gave exceptionally efficient circularly polarized red emission from these simple small organic fluorophores , enabling future application in cplbased bioimaging .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
incidence of ep ranges between 0.25% to 2% of all pregnancies . in 95% of eps ,
fertilized ovum implants in the tubes , but rarely in other organs like abdomen , ovaries , cervix , spleen , omentum , cessarian section scar , and intramural .
the death rate is about 1 per 2000 eps and 15% of all maternal deaths .
incidence of ep is nearly double in black women who also have a four times greater risk of ep - related mortality than white women .
the risk factors for ep include pelvic inflammatory disease , previous tubal surgery , previous tubal pregnancy , progestin contraceptive , assisted reproduction , ovulation induction , induced abortion , salpingitis isthmica nodosa , smoking , and diethyl stilbestrol exposure .
most of the tubal pregnancies become symptomatic within 12 weeks , but a small number of them progress beyond this gestation and are diagnosed late .
proper management of ep needs early diagnosis , resuscitation , timely treatment , and follow - up .
early diagnosis of ep is a difficult task but can be possible with the help of quantitative -human chorionic gonadotropin ( -hcg ) level , transvaginal ultrasonography , and laparoscopy .
knowledge of the risk factors for ep helps in rapid diagnosis and could reduce the need for surgery and suggest actions to improve prognosis .
however , several studies assessing risk factors for ep have been published from developed countries .
saudi women have different characteristics , like cultural , religious , sociodemographic , sexual behavior , beliefs , and contraception practices , than those of developed countries and may have different risk factors for ep .
the purpose of this study was to highlight the frequency and predisposing factors of ep , and to elucidate the outcome after different treatment modalities in a general hospital .
this retrospective descriptive study was conducted at hera general hospital , makkah , saudi arabia , over a duration of 18 months from july 1 , 2009 to december 31 , 2010 .
the study subjects included all females in their reproductive age who were admitted at the obstetrics and gynaecology department with suspicion of ep .
data were retrieved from the medical record office by exploring the patients files in detail .
patients files were looked for age ; gravidity ; gestational age ; clinical presenting features ; and ep risk factors , like history of previous abortion , infertility treatment , current use of intrauterine contraceptive device ( iucd ) , history of previous tubal surgery and pelvic surgery , previous ectopic and/or pelvic inflammatory disease .
peak level of -hcg , transvaginal ultrasonographic findings , mode of treatment , and type of surgical procedure were also retrieved . a woman experiencing several eps during the study period generated multiple case entries , one for each ep episode . in this study , seven women experienced two , and two women experienced three eps .
the duration from symptoms onset to admission and admission to definite treatment was also recorded .
numerical data were subjected to descriptive analysis , with mean  standard deviation ( sd ) .
the institutional review board of hera general hospital , makkah , saudi arabia , granted us permission to conduct this study .
the institutional review board of hera general hospital , makkah , saudi arabia , granted us permission to conduct this study .
incidence was 0.58% out of 7654 pregnant women admitted at the department of obstetrics and gynaecology ( 5.8/1000 pregnancies ) .
the mean age of the women was 27.9  7 years and only 2 ( 4.5% ) were more than 40 years old .
twenty - five ( 56.8% ) were multigravida whereas 21 ( 47.7% ) presented at 7 - 8 weeks of gestation .
the range of gestational age was 3 - 9 weeks at presentation . only 24 ( 54.5% ) patients presented within 24 h , 6 patients within 1 - 2 days , and 14 patients presented after 2 days of onset of symptoms of ep .
the most common presenting feature was amenorrhea ( 41 , 93.2% ) , followed by abdominal pain ( 39 , 88.6% ) and abdominal tenderness ( 38 , 86% ) .
fluid in pouch of douglas was found in 21 ( 55.3% ) cases and ectopic mass in 13 ( 34.2% ) cases [ tables 1 and 2 ] .
demography and obstetrical history clinical presentation of ectopic pregnancy sixteen ( 36.3% ) females presented with hemoglobin levels of 8 - 10 gm% , followed by 13 ( 29.5% ) with  10 - 12 gm% , 9 ( 20.5% ) with  12 - 14 gm% , and 6 ( 13.6% ) with  8 gm% . twenty - three ( 52.3% ) patients did not receive any blood transfusion during their hospital stay , but 11 patients received one , 5 received two , 3 received three , and 2 patients received  4 units of blood transfusion . out of 44 patients ,
25 underwent emergency laparotomy whereas the remaining 19 patients were admitted for observation and further diagnosis .
when diagnosis was proved , 12 underwent laparoscopy whereas seven received medical treatment by methotrexate ( mtx ) and it was successful in all cases . on the other hand , salpingectomy was performed in 33 ( 89.1% ) cases followed by salpingostomy in 2 ( 5.4% ) , whereas one case underwent salpingotomy and resection of ectopic mass was performed for the remaining one patient .
pre - operative findings for 37 cases revealed that 35 ( 94.6% ) females had ep in the fallopian tube , whereas one case had within the ovary and one had heterotopic pregnancy , i.e. , combined intra- and extra - uterine .
average hospital stay after surgery was 4 days in laparotomy and 2 days in laparoscopy .
eighty percent ( n = 35 ) had some risk factors , whereas previous pelvic surgery was most frequently seen ( 13 , 29.5% ) followed by history of pelvic inflammatory disease ( 10 , 22.7% ) [ table 3 ] .
the rate of ep was 1.9% as reported by lozeau and potter in usa , and 1.04% and 1% by bangash and ahmad , and waseem , respectively , in pakistan .
our study was conducted in a secondary healthcare center , which is why we were not receiving referral cases from the whole of the makkah region , and incidence represented the incidence in hera general hospital rather than the general population of the region .
mtx treatment of ep was safe and effective for selected patients with unruptured tubal ep , with no major side effects as found by dhar et al .
a paper presented in a conference proceeding highlighted management of advanced ep , i.e. , in bahrain , managements of ep were as follows : laparotomy and salpingectomy ( 84.2% and 5.3% ) , mtx alone ( 5.3% ) and mtx followed by laparotomy and salpingectomy ( 10.5% ) , whereas in qatar it was laparoscopy and salpingectomy ( 77.6% ) , mtx alone ( 19.4% ) , and mtx followed by laparoscopy and salpingectomy ( 3% ) .
laparoscopy in qatar and laparotomy in bahrain were the treatment of choice to treat advance ectopic cases .
lozeau and potter reported a success rate of 88% in a single - dose versus 93% in a multiple - dose regimen of mtx .
salpingostomy was concluded as a better option than salpingectomy regarding the future fertility outcome in one study .
we tried in our study to increase the clinical knowledge and the degree of suspicion of the physicians to diagnose the ep as early as possible .
this will avoid delay in presentation and diagnosis , which is vital to avoid morbidity and mortality in patients with ep .
after a review of the literature and our study results , we are in a position to recommend the following steps at three levels i.e. , public , primary healthcare , and specialist center .
aim should be early diagnosis and prompt treatment of ep without unnecessary delay in presentation , diagnosis , and treatment .
we should launch a public awareness program about the risk factors to educate all females through electronic media like tv , radio , or newspapers .
all these patients should register themselves at a specialist hospital for care of their pregnancy where specialist gynecologists and facilities for diagnosis and treatment of ep are available .
general practitioners working in primary healthcare centers should be educated to have a high index of suspicion for ep . at specialist - level hospitals , all females ( at their child - bearing age ) presenting with hemodynamic instability or pain in the lower abdomen should be admitted and immediate investigations like pregnancy test , -hcg , and ultrasound ( both trans - abdominal and trans - vaginal ) should be ensured even if there is no history of amenorrhea .
this study found that previous pelvic surgery , infertility treatment , and pelvic inflammatory disease were the major predisposing factors for ep .
the most common site was the fallopian tube and the success rate of mtx was found to be 100% .
to avoid emergency laparotomy that has its own post - operative complications , timely diagnosis of ep should be encouraged .

Answer:
objectives : the objective was to highlight the frequency , clinical profile , and predisposing factors of ectopic pregnancy ( ep ) in a general hospital.materials and methods : this descriptive study was conducted at the obstetrics and gynaecology department of hera general hospital , makkah , saudi arabia , from july 1 , 2009 to december 29 , 2010 .
 data were collected on chief medical complaints , sociodemographic characteristics , past obstetrics and gynecological history , management done , and outcome of management .
 data were analyzed using microsoft office excel ( version 2007).results : out of total 7564 pregnancies , 44 ( 0.58% ) patients were diagnosed as ep . out of 44 , 22 ( 50% )
 patients presented within 24 h of onset of symptoms .
 mean age was 28  7 years .
 multigravida were predominant in 25 ( 57% ) , and 21 ( 48% ) had gestational age of 6 - 8 weeks at the time of presentation ; the common presenting features were amenorrhea ( 41 , 93.2% ) , abdominal pain ( 39 , 88.6% ) , and tenderness ( 38 , 86% ) .
 previous pelvic surgery ( 13 , 29.5% ) , infertility treatment ( 11 , 25% ) , and pelvic inflammatory disease ( 10 , 22.7% ) were the common predisposing factors .
 twenty - five ( 57% ) presented with ruptured ep and were operated within 24 h , and the remaining were kept under observation till further diagnosis . after confirming the diagnosis , 12/19 underwent laparoscopy , whereas 7/19 received medical treatment .
 surgery confirmed fallopian tube pregnancies in 35 ( 94.5% ) .
 no mortality was observed.conclusion:previous pelvic surgeries were the major etiological factor for ep .
 other factors were infertility treatment and pelvic inflammatory disease .
 the most common site of ep was fallopian tubes .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
physical activity during preschool age has significant effects on physical , social and psychological health of children .
fundamental movement skills ( fms ) including locomotor ( e.g. run , gallop , hop , leap , horizontal jump and slid ) , object control ( e.g. catch , kick , overhand throw and dribble ) and body management ( e.g. balance , climb and forward roll ) provide a base for more advanced physical skills . fms develop during early childhood and are essential for complex activities at adulthood .
some studies have shown that the level of locomotor skills of children is positively correlated with the levels of participation in physical activities at adulthood[34 ] .
d'hondt et al reported that the levels of gross motor skills in obese children are lower than the levels of these skills in normal - weight children .
therefore it seems likely that more proficient children in fms are more physically active , have more self confidence , are less obese and would be healthier in their adulthood .
fms would not be developed naturally as a result of growth and maturation in all children .
it has been suggested that the optimal ages for fms learning are between 2 to 7 years[2 , 6 ] .
brian w et al have recommended that physical activity promotional programs for preschool children should be on base of children 's natural activities such as being spontaneous and intermittent . also preschool children activities should be enjoyable and contain gross motor plays and locomotor activities .
therefore , it seems that an effective physical activity program for preschool children needs to be developmentally appropriate for children in the listed age range .
furthermore , physical , emotional and psychosocial needs of children should be considered in development of appropriate physical activity program for these children . ideally physical activity programs in nursery schools
also a well developed training course for these instructors is essential in efficient teaching of movement skills to children in nursery schools[1 , 9 ] .
in addition to the role of fms in long - term health , fms play a cardinal role in physical development of preschool children . to our knowledge
there is no national curriculum for preschool children physical activity education in iranian nursery schools .
the objectives of this study were a ) to develop a physical activity program for nursery schools in iran , and b ) to evaluate the effects of this program on improvement of fundamental movement skills of preschool children in selected nursery schools in iran .
this quasi - experimental study evaluated the effect of a 10 weeks physical activity program on fundamental movement skills levels of nursery children in iran .
the participants were 147 children with age range between 4 to 6 years that were selected by convenience sampling .
children selected form five available nursery schools in five different cities in iran . a manual for nursery physical activity instructors was developed by a panel of 20 experts in different related fields in iran including sports medicine specialist , pediatrician , expert nursery teachers , psychologist , nutritionist , physical education specialist , phd in sports physiology , and phd in movement and behavior .
this manual contained two parts ; a ) instructions for nursery physical activity instructors about goals and structure of the program , and materials on children 's growth and development , children 's nutrition , physical education , psychology of children , and health and safety , b ) twenty four sections which cover different lessens containing physical activity and games aimed at developing locomotor and object control skills of children aged 4 to 6 years .
some sections of this package were developed based on the iranian traditional games and plays that were appropriate for preschool ages .
five nursery schools were selected in five different cities ( tehran , isfahan , shahrood , neishaboor and gorgan ) and volunteer nursery teachers of these nursery schools were enrolled in an educational course .
this one week course was designed to train nursery physical activity instructors to be able to physically train children in nursery based on our designed physical activity program .
the aim of this short - term educational program was to ensure that all physical activity instructors are alert to their duties about implementing of the developed physical activity manual .
also physical activity instructors were educated to test children using the test of gross motor development - edition 2 ( tgmd-2 ) before and after intervention .
persian version of this test has been employed by akbari h , et al . and bakhtiari s , et al . in iran[9 ,
the levels of gross motor development of all subjects were measured before intervention and after 10 weeks physical activity program employing tgmd-2 .
tgmd-2 is a valid and reliable ( test - retest reliability = 0.88 - 0.96 ) criterion - referenced instrument designed to assess gross motor development among children .
each subtest consists of 6 locomotor items ( run , hop , gallop , leap , horizontal jump , and slide ) , and 6 object control items ( throw , catch , kick , strike , dribble , and roll ) .
subtest raw score was defined by sum of 6 items of each subtests of locomotor or object control ( scored between 0 - 48 ) .
standard scores of each subtest ( scored between 0 - 20 ) and also gross motor quotient were calculated in accordance with tgmd-2 manual .
( gmq ) for each subject was reported as very superior ( gmq > 130 ) , superior ( gmq = 121130 ) , above average ( gmq = 111120 ) , average ( gmq = 90110 ) , below average ( gmq = 8089 ) , poor ( gmq = 7079 ) , and very poor ( gmq < 70 ) according to the suggestions of the tgmd-2 manual . according to developed physical activity manual
, physical activity program was conducted 5 days a week for 10 weeks by trained nursery physical activity instructors .
paired - samples t test was used to determine whether there were significant differences between the levels of locomotor and object control of participants before and after intervention .
independent samples t - test was used to compare differences between boys and girls on variables .
in this quasi - experimental study 147 children with mean ( sd ) age of 4.95 ( 0.8 ) ( range 3 - 6 ) year from five nursery schools in 5 cities in iran were included .
of all subjects 49% ( 72 ) were girls and 51% ( 75 ) were boys .
the base line and post intervention tgmd-2 scores of subjects are presented in tables 1 and 2 . in the baseline
, there were no statistically significant differences between the locomotor and object control raw scores of boys and girls ( p=0.49 and p=0.9 ) respectively .

base line and post intervention tgmd-2 scores of all subjects sd : standard deviation means ( sd ) of base line and after intervention tgmd-2 raw scores of all subjects by age and gender sd : standard deviation after intervention , differences between the locomotor raw scores of boys and girls were not statistically significant ( p=0.5 ) .
however , there was a statistically significant difference between boys and girls in the object control raw scores ( p=0.048 ) .
the gmq of all subjects which is the most reliable score of tgmd-2 was statistically significantly increased after 10 weeks of intervention .
both subtests of tgmd-2 including  locomotor raw score  and  object control raw score  in both genders were statistically significantly increased after 10 weeks of intervention ( table 1 ) .
descriptive rating of gmq for subjects before and after intervention is shown in table 3 . before intervention only 11.5% of all subjects were rated superior / very superior in gmq scores ( i.e. gmq > 120 ) , however this rate increased to 49.7% of all subjects after 10 weeks of intervention . before the intervention ,
26.6% of all subjects were rated as poor / very poor , this rate decreased to 2% of subjects after 10 weeks intervention .
age equivalents of subjects on the locomotor and object control subtests before and after intervention are shown in table 4
. age equivalents or developmental age defined as  developmental level or age that corresponds to a raw score made by an individual  .

descriptive rating of the gross motor quotient of all subjects before and after intervention age equivalents for locomotor and object control raw scores according to age groups of all subjects before and after intervention
the main finding of this study was that the developed physical activity intervention program that was focused on gross motor skills development had a significant positive effect on proficiency in fundamental movement skills in preschool children from selected nursery schools in five cities in iran .
differences in tgmd-2 results before and after the intervention were significant in locomotor , object control , sum of standard cores and gross motor quotient in all subjects . to our knowledge
there has been no published data on the levels of physical activity of iranian preschool children .
however , base line tgmd-2 subtests scores of our subjects in this study were in the range of reported data from the united states ( table 5 ) .

comparison of tgmd-2 standard scores of subjects in this study with reported data from the united states , mean ( sd ) sd : standard deviation our data suggested that a supervised physical activity program could increase these scores to be better than normative reported data .
there was no significant difference in the base line mean of the locomotor and object control raw scores between girls and boys ( 30 vs 29.5 ) and ( 24.8 vs 26 ) , respectively .
however after the intervention the mean of both object control raw scores ( p=0.048 ) and object control standard scores ( p=0.02 ) in girls were higher than these scores in boys .
cliff et al have reported that locomotor raw score in preschool children was higher in girls compared with boys but there was no significant difference between girls and boys in the object control raw score . in this study ,
base line means of standard scores of the locomotor ( 9.3 vs 8.9 ) , object control ( 9.1 vs 8.1 ) and gmq ( 95.5 vs 91.2 ) were not significantly different between girls and boys .
in contrast cliff et al have reported significant differences between girls and boys in the mean of locomotor standard scores ( 9.9 vs 7.9 ) , object control standard scores ( 10.1 vs 8.6 ) and gmq ( 99.7 vs 88.2 ) .
one study has reported that locomotor skills proficiency is higher in girls and in contrast boys are more proficient in object control skills .
some studies have suggested that the levels of moderate and vigorous physical activities in children with better motor performance are significantly higher than the levels of these activities in children with less developed skills[4 , 19 ] .
therefore , conduction of a physical activity program such as the program used in this study may help children to improve their fms which may help to have a higher physical activity in their future .
first , same person conducted both training sessions and outcomes measurement in each nursery school .
furthermore , to our knowledge there was no normative data of tgmd-2 for iranian children to be used for comparison with our data .
further studies are needed to evaluate the long - term effects of physical activity intervention on fms in iran .
it seems that our developed physical activity program conducted by trained nursery physical activity instructors could be an effective and practical way of improving gross motor skills of preschool children in short term in iran .
conduction of this program in nursery schools could indirectly help with increasing health levels and levels of physical activities in the society .
we recommend using of this kind of physical activity programs in all nursery schools in iran and similar counties .

Answer:
objectivethe objectives of this study were a ) to develop a physical activity program for nursery schools , and b ) to evaluate the effects of this program on fundamental movement skills of preschool age children in iran.methodsin this quasi - experimental study 147 children from five nursery schools in five different cities in iran were enrolled .
 a physical activity program was developed for nursery children .
 trained nursery physical activity instructors conducted the program for 10 weeks for all subjects .
 the levels of gross motor development of all subjects were measured before intervention and after 10 weeks physical activity program employing the test of gross motor development - edition 2 ( tgmd-2).findingsthe participants in this study had a mean ( sd ) age of 4.95 ( 0.83 ) years . at the end of the study , scores of subjects at all components of tgmd-2 ( including locomotor , object control , sum of standard scores and gross motor quotient )
 were significantly improved compared to the baseline scores ( p<0.001 ) .
 based on descriptive rating of the " gross motor quotient " in the base line , 11.5% of subjects were superior / very superior ( gmq > 120 ) and after 10 weeks intervention this rate was increased to 49.7% of all subjects.conclusionit seems that the developed physical activity program conducted by trained nursery physical activity instructors could be an effective and practical way of increasing levels of fundamental movement skills of preschool children in iran .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
first described in 1910 , purtscher s retinopathy is seen in severely traumatized patients and is characterized by sudden visual loss ( purtscher 1912 ) .
the characteristic ophthalmoscopic findings are multiple areas scattered throughout the posterior pole of superficial retinal whitening , which appear as focal areas of retinal arteriolar occlusion on fluoresceinangiography ( grass 1997 ) .
similar clinical findings have been reported in association with childbirth ( blodi et al 1990 ; shaikh et al 2003 ) , and have been termed purtschers - like retinopathy . the visual prognosis in purtschers - like retinopathy after childbirth is guarded , and to date , there is no definitive treatment .
however , there are encouraging reports of visual recovery in patients with purtscher s retinopathy receiving high dose intravenous corticosteroid therapy ( atabay et al 2003 ) .
we report a patient with purtschers - like retinopathy following childbirth who received a sub - tenon s capsule injection of triamcinolone with subsequent increase in visual acuity and decrease in retinal swelling .
ten days after an emergent caesarian section for severe preeclampsia , rh immunization , and fetal anemia , a 24 year - old primigravida primiparus patient presented with complaints of decreased vision in both eyes , right greater than left . there were no other systemic abnormalities such as elevated liver enzymes , low platelets or other hematologic abnormalities .
dilated fundus examination revealed bilateral purtschers - like retinopathy ( figures 1a , 1b ) , with widespread areas of macular ischemia and edema , as confirmed by optical coherence tomography ( figures 2a , 2b ) .
of note are the superficial areas of high intensity signal , indicative of retinal ischemia .
the central thickness in the right eye was 272 microns , and in the left 239 microns .
a sub - tenon s injection of 0.5 cc of triamcinolone ( 40 mg / cc ) was given in the right eye on day 15 after delivery .
at one week following the injection , her visual acuity was unchanged and her intraocular pressure was normal .
she noted a marked improvement in the vision in her right eye . on examination a her acuity
had improved to 20/60 in the right eye and 20/20 in the left , with normal intraocular pressures .
her fundus examination showed marked improvement , with most of the superficial ischemic areas resolving .
repeat optical coherence tomography in both eyes ( figures 3a , 3b ) demonstrated a reduction in the edema of the right eye by 30% from baseline , whereas the left , untreated eye showed a reduction in swelling of 14% .
her visual acuity remained 20/60 in the right eye and 20/20 in the left eye .
nearly a century ago otmar purtscher described a case of visual loss in a severely traumatized patient whose exam showed multiple superficial retinal hemorrhages and white patches throughout the posterior pole . since that time , similar findings have been associated with other conditions including compressive chest injuries , acute pancreatitis , fat embolism , retro - bulbar anesthesia , connective tissue diseases ( grass 1997 ) , and childbirth ( blodi et al 1990 ; shaikh et al 2003 ) .
the pathogenesis of purtschers - like retinopathy post - partum is unknown , but may be related to arteriolar obstruction by complement induced leukoemboli produced during parturition ( blodi et al 1990 ) .
similar clinical findings have been reported in the setting of amniotic fluid embolism . however , in the absence of a patent foramen ovale or pulmonary arteriovenous - shunts , it is unlikely that amniotic emboli are the direct cause of the observed retinal arteriolar obstructions .
other investigators have theorized that subclinical amniotic fluid emboli may activate complement and induce granulocyte microemboli , which could occur on both sides of the pulmonary capillary bed .
the visual recovery of postpartum patients with purtschers - like retinopathy is varied ( blodi et al 1990 ; shaikh et al 2003 ) . of the four patients described by blodi , three enjoyed significant improvement in central acuity ,
another case of purtscher - like retinopathy has been described in a patient with hellp syndrome during antepartum .
generally purtscher - like retinopathy has a favorable prognosis but this case resulted in permanent loss of vision ( stewart et al 2007 ) .
currently , there is no definitive treatment for postpartum purtschers - like retinopathy . in vivo
, corticosteroids have been shown efficacious in inhibiting complement - induced granulocyte aggregation ( hammerschimidt et al 1979 ) .
clinically , there are two reports of visual recovery after high dose , intravenous corticosteroid therapy in post - traumatic patients ( atabay et al 1993 ) .
the case presented here is unique in that the patient had bilateral , asymmetric purtschers - like retinopathy post - partum , with quantitative oct improvement following unilateral local steroid therapy .

Answer:
sub - tenon s injection of triamcinolone was performed in the right eye of a patient with bilateral purtschers - like retinopathy after childbirth .
 the response of macular edema to local triamcinolone was investigated with optical coherence tomography .
 five weeks following the injection , optical coherence tomography improvement was seen following unilateral sub - tenon s triamcinolone injection .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
the retrorectal space is an uncommon area where tumors occur and these include primary tumors of neurogenic , osteogenic , and congenital origin ; in addition to metastatic and inflammatory processes .
congenital lesions include chordomas ( remnants of notochord ) , teratomas , anterior sacral meningoceles , and developmental cysts ( dermoid , epidermoid , enteric duplication , and tailgut cysts ( tgcs ) ) .
tgcs , also known as retrorectal cystic hamartomas , are a rare congenital lesion thought to arise from the remnants of the embryonic postanal gut .
hjermstad and helwig were the first to publish their findings in 1988 , and since then there have been no large case series reported . from review of the literature done by killingsworth and gadacz (
keyword = tailgut cyst or retrorectal cystic hamartoma , limits = english ) , there have been 43 cases with confirmed diagnosis of tgc since their report .
a 15-year - old girl presented with the complaints of lower abdominal pain and constipation occasionally .
however , on per rectal examination , there was a mass bulging from the posterior rectal wall , firm , and non - tender , with regular surface and smooth mobile rectal mucosa over it .
an ultrasonogram ( abdominal ) revealed a large cystic lesion present in the left lower abdomen and the left ovary could not be seen separately .
the patient then underwent a contrast - enhanced computed tomography ( cect ) of the abdomen and pelvis which revealed a well - defined 12  13  9 cm multiseptated lesion in the presacral space which was pushing the rectum laterally and urinary bladder superiorly and abutting the sacrum and coccyx posteriorly [ figure 1a and b ] .
the lesion was showing peripheral and septal calcification , few hyperdense nonehancing areas and few ossified fragments within it .
a provisional diagnosis of mature cystic teratoma was made and the patient underwent exploratory laparotomy wherein a large tubular tense cystic mass resembling fluid - filled intestinal loop filled with thick mucoid material was present in the presacral space [ figure 2 ] .
the two ends of the tube were merging at the coccyx . the mass was displacing the sigmoid colon and rectum laterally and urinary bladder anteriorly . en masse removal was done .
cect abdomen showing multiseptated pre sacral mass compressing the rectum and displacing bladder superiorly intraoperative picture showing a tubular fluid - filled structure displacing the bowel loops the patient had an uneventful postoperative recovery
. the histopathological examination revealed it to be a retrorectal cystic hamartoma with areas of intestinal ( large and small ) and gastric epithelium .
a solitary solid area within it had intestinal lining with area of squamous epithelial nests , haphazardly arranged muscle bundles , nerve bundles , and serous acini with few cystic spaces [ figure 3a  c ] .
histopathological image showing ( a ) gastric mucosa , ( b ) ectopic gastrointestinal gland and ( c ) ectopic pancreatic epithelium
the retrorectal space is a potential space developed when a mass displaces the rectum anteriorly .
the pelvic peritoneal reflection forms the superior border , and the levator ani and coccygeus muscles form the inferior border .
the differential diagnosis of masses within this space is broad and includes primary tumors of neurogenic , osteogenic , and congenital origin ; in addition to metastatic and inflammatory processes .
congenital lesions include chordomas , teratomas , anterior sacral meningoceles , and developmental cysts ( dermoid , epidermoid , enteric duplication , and tgcs ) . excluding inflammatory lesions , developmental cysts are the most common masses in the retrorectal space .
. only one case of a retrorectal cystic hamartoma occurred in a 2-year - old child and very few cases have been reported in teen aged girls , as in our case .
the differential diagnosis for a retrorectal mass can be narrowed using a combination of diagnostic tools to reach a preoperative diagnosis of a developmental cyst . due to their location
, almost all retrorectal tumors will be palpable on rectal examination , and developmental cysts will manifest as extrinsic masses .
ct and magnetic resonance imaging ( mri ) are useful imaging modalities that help in making a preoperative diagnosis . however , the definitive diagnosis and treatment is through complete surgical excision and pathological examination of the specimen .
preoperative biopsy should not be attempted ( unless the mass is surgically unresectable at presentation ) due to risk of spreading dysplastic cells through weakened cyst walls .
in addition , tissue obtained from biopsy is often not extensive enough to show all the histology features necessary for diagnosis .
dermoid and epidermoid cysts are both lined with stratified squamous epithelium ; however , only dermoid cysts contain dermal appendages ( hair follicles , sweat glands , and tooth buds ) .
epidermoid cysts are formed from inclusion of epidermal elements at the time of neural groove closure in the meninges .
rectal duplication cysts are lined by typical gastrointestinal epithelium ( often with crypts , villi , and glands ) and are surrounded by two well - formed layers of smooth muscle with nerve plexuses .
tgcs , or retrorectal cystic hamartomas , are predominantly multicystic and can contain a variety of epithelia between cysts or even within the same cyst .
epithelial types include stratified squamous , transitional , mucinous or ciliated columnar , and cuboidal mucus secreting .
in contrast to enteric duplication cysts , tgcs have disorganized smooth muscle fibers within the cyst wall and do not contain neural plexus .
retrorectal hamartoma or tgc should be considered as a possible differential in any case of perirectal cyst , irrespective of age and gender .

Answer:
the retrorectal space is an uncommon seat for neoplastic masses .
 retrorectal hamartoma or tailgut cyst ( tgc ) is an uncommon developmental cystic lesion occurring in this space which mostly occurs in middle - aged females .
 we recently cared for a 16-year - old girl who presented with vague lower abdominal pain and occasional constipation .
 per rectal examination revealed an extraluminal mass bulging from posterior rectal wall .
 preoperative radiological investigations revealed by suggested it to be a mature cystic teratoma .
 the patient underwent exploratory laprotomy with en masse excision of the cyst .
 histopathological examination of the specimen showed it to be a tgc .
 this case highlights the possibility of a tgc as a differential for retrorectal cystic lesions and the need to completely excise them given the possibility of future malignant transformation .