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 prevalence of obesity in children and adolescents is increasing world - wide , notably in developing countries .
now - a - days , this problem has become one of the important concerns about general health at the global level .
obesity in childhood and adolescence has different effects on mental health , including symptoms of anxiety , depression , insomnia , social isolation etc .
, in turn , these conditions would have negative consequences on social relationships and learning issues .
some studies documented higher prevalence of mental disorders as depression and anxiety in obese than in normal - weight individuals .
in contrast , the prevalence of mental disorders is increasing in children around the world ; this can be due to the escalating trend of childhood obesity . due to the importance of mental health
, it is considered as part of the world health organization global school - based health survey ( who - gshs ) .
similar to most other developing countries , iran is facing double burden of nutritional disorders .
some studies in iran have considered the relationship of overweight and obesity with mental disorders . although most studies in western countries found a higher prevalence of psychiatric disorders in overweight children and adolescents , but studies conducted in two cities in iran did not document the relationship of body mass index ( bmi ) with depression and anxiety in iranian students .
because of diversity in the cultural and socioeconomic background in different regions of iran , it is necessary to extrapolate such investigations in different parts of the country to help in designing and implementing health promotion programs .
this nationwide study aims to assess the relationship of excess weight with some mental disorders in iranian students by using the who - gshs questionnaire .
this nationwide cross - sectional study was conducted as part of the third national survey of a school - based surveillance system entitled the childhood and adolescence surveillance and prevention of adult non - communicable disease - iii study .
after explanation of the study aims and methods , verbal assent was obtained from students and written informed consent from their parents .
this study was conducted in 2009 - 2010 among 5570 students , aged range from 10 to 18 years .
they were selected by random cluster sampling from urban and rural areas of 27 provinces in iran .
the questions related to the mental distress are presented in appendix i. trained health professionals conducted the physical examination under standard protocols and by using calibrated instruments .
bmi was calculated as weight ( kg ) divided by height squared ( m ) .
continuous variables are expressed as mean ( standard deviation [ sd ] ) and categorical variables are presented as number ( percentage ) .
logistic regression analysis was used to assess the association of obesity and overweight with mental disorders .
continuous variables are expressed as mean ( standard deviation [ sd ] ) and categorical variables are presented as number ( percentage ) .
logistic regression analysis was used to assess the association of obesity and overweight with mental disorders .
their mean sd age was 14.7 ( 2.4 ) years , without significant difference in terms of gender .
table 1 shows the frequency of anxiety according to gender and bmi categories . according to their self - report
, 3182 ( 58.7% ) students had anxiety , which consisted of 1417 ( 53.1% ) girls and 1765 ( 64.7% ) boys .
no significant association was documented neither between overweight and anxiety ( odds ratio [ or ] : 0.86 , 95% confidence interval [ ci ] : 0.68 - 1.09 ) , nor between obesity and anxiety ( or : 1.11 , 95% ci : 0.88 - 1.40 ) . frequency of self - reported anxiety among iranian adolescents by gender and weight status : the caspian - iii study as can be seen in table 2 , 3389 ( 62.6% ) of students reported to have depression , they consisted of 1643 ( 61.1% ) girls and 1746 ( 64.3% ) boys reported to have depression .
there was no significant relationship between overweight and depression ( or : 1.11 , 95% ci : 0.86 - 1.43 ) and between an obesity and depression ( or : 1.01 , 95% ci : 0.79 - 1.29 ) . the self - reported frequency of insomnia among students is presented in table 3 .
it shows that 2618 ( 49.4% ) of students consisting of 1285 ( 49.1% ) girls and 1333 ( 49.7% ) boys had insomnia .
no significant relationship was found neither between overweight and insomnia ( or : 1.17 , 95% ci : , 0.91 - 1.51 ) , nor between obesity and insomnia ( or : 0.91 , 95% ci : 0.71 - 1.17 ) .
frequency of self - reported depression among iranian students by gender and weight status : the caspian - iii study frequency of self - reported insomnia among iranian students by gender and weight status : the caspian - iii study
this study , which is the first nationwide study of its kind in iran , showed that overweight and obesity were not associated with depression , anxiety and insomnia in iranian adolescents .
contrary to our findings , several studies in western countries have documented higher prevalence of these mental disorders in overweight and obese individuals .
these differences could be because of social and cultural differences , especially the attitude of friends , family members and the community to obesity and obese person in various societies .
similar to previous studies in iran , our findings propose that overweight and obesity in adolescence are well - accepted by the community and therefore the overweight or obese person is not under pressure by parents and peers .
some previous studies have suggested that obese children , who are mocked by their friends , would experience some negative feelings including shame , isolation and depression .
moreover , these studies proposed that pressure and sneap imposed by parents is increased in overweight and children and adolescents .
it is also suggested that depression might lead to unhealthy behaviors and in turn might result in overweight and obesity .
the current study showed that anxiety and depression are more prevalent in boys than in girls .
some previous studies reported higher prevalence of such disorders in 12 - 18-year old girls and 10 - 12-year old boys .
they suggested that such differences might be because of hormonal changes during puberty . in another study ,
depression was reported to be more prevalent in girls with 15 - 18 years of age and boys aged 10 - 14 years .
further studies shall be conducted about the effects of various items including genetic , environmental , cultural , social and nutritional factors on gender differences documented by various studies about the psychiatric distress during adolescence .
the present study did not find any significant difference in the prevalence of insomnia according to gender and weight status .
some studies documented higher prevalence of insomnia in girls and obese individuals . in our study , the prevalence of depression and anxiety was more than a previous study in iran , however , our finding is consistent with some other studies . study limitations and strengths : the main limitations of this study are its cross - sectional setting and using self - reported data on psychiatric distress among adolescents .
the main strengths are the novelty in the region , recruiting a large sample size of adolescents from diverse parts of the country , as well as using an internationally accepted questionnaire .
we did not find significant relationship between excess weight and psychological distress in iranian students .
this can be because of positive attitude of iranian families toward fatness in childhood and adolescence .

Answer:
background : excess weight may be associated with mental distress and this relationship varies according to the socio - cultural background of different populations .
 this study aims to assess the relationship of overweight and obesity with some psychological disorders in a nationally representative sample of iranian adolescents.methods:this nationwide study was conducted in 2009 - 2010 among 5570 students , aged 10 - 18 years , living in 27 provinces in iran .
 data were collected by using the translated and validated questionnaire of the world health organization global school - based health survey.results:data of 5528 students ( 49.7% girls ) were complete for this study .
 their mean age was 14.7 ( 2.4 ) years .
 overall 7.9% of participants were overweight and 8.8% were obese .
 58.7% of students had anxiety , without significant association of overweight ( odds ratio [ or ] : 0.86 , 95% confidence interval [ ci ] : 0.68 - 1.09 ) and obesity ( or : 1.11 , 95% ci : 0.88 - 1.40 ) with an anxiety .
 nearly 62.6% of students reported to have depression , there was no significant relationship between overweight ( or : 1.11 , 95% ci : 0.86 - 1.43 ) obesity and ( or : 1.01 , 95% ci : 0.79 - 1.29 ) with the depression .
 about 49.4% of students had insomnia , without significant association of overweight ( or : 1.17 , 95% ci : , 0.91 - 1.51 ) and obesity ( or : 0.91 , 95% ci : 0.71 - 1.17 ) with the insomnia.conclusions:in iranian adolescents , excess weight did not increase the risk of psychological distress .
 this finding might be due to the positive attitude of family and peers to fatness in adolescence .


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:
chest pain is a typical symptom of acute coronary syndrome ( acs ) , of which there are three common types : unstable angina ( ua ) , st segment elevation ( stemi ) of myocardial infarction ( mi ) , and non - st - segment elevation of mi ( nstemi ) [ 1 , 2 ] .
symptoms of acs in the absence of chest pain are dyspnea , nausea , sweating , neck or jaw and arm pain .
ear pain and sore throat are rare symptoms of acs , which makes diagnosis and treatment difficult and challenging .
we present a rare case of a patient presented to the emergency department of our hospital with symptoms of earache and sore throat for cardiac ischemia .
a 53-year - old african - american female presented to the ed complaining of earache and sore throat for 3  days .
she described the pain as a burning sensation that was worst when she woke up in the morning and got better as the day progressed .
the patient denied chest pain , shortness of breath , nausea , vomiting , or dizziness .
the patient worked as a telemarketer , described her job as very stressful , and claimed to smoke one to two cigarettes per week .
her medical history was significant for dyslipidemia , newly diagnosed type 2 diabetes , and chest discomfort diagnosed 4 months ago at a different hospital as stemi with complete occlusion of the rca .
she was treated at the hospital by placement of a bare - metal stent in her rca .
current home medications included clopidogrel , aspirin , statin , beta - blocker , metformin , and nitroglycerin sublingually as needed for chest pain .
her vital signs on arrival at the ed were : bp of 131/82  mmhg , pulse of 70 beats per minute , respiratory rate of 17 breaths per minute , temperature of 98 f , and oxygen saturation of 98% on room air . because of multiple risk factors , in addition to a symptom that could potentially be a referred cardiac pathology , an ecg , chest radiograph , and cardiac biomarkers were ordered at the triage .
cardiovascular , pulmonary , abdominal , ear , nose , and throat examinations were unremarkable .
the initial ecg displayed no st segment elevation , but t wave inversion in inferior leads that was unchanged from a previous ecg .
a presumptive diagnosis of acs/ nstemi was made on the basis of an elevated troponin combined with the ecg changes .
after the acs protocol was initiated , a cardiology consultation was requested , and the patient was admitted to our hospital . on admission ,
the patient continued to complain of throbbing ear pain that fluctuated now between the two ears , but again denied chest pain or shortness of breath . on the 2nd day
it was found that the previous bare - metal stent in the posterolateral branch ( distal rca ) was completely occluded , and no balloon could be advanced beyond that area .
a new lesion in the proximal / ostial rca greater than 70% occlusion was opened with a successful placement of a pci at the ostial rca using a drug - eluting stent . following this ,
her troponin level had declined to 0.63  ng / m on the 3rd day , and the patient was discharged with a referral for cardiac rehabilitation .
we concluded on follow - up that otalgia in this patient was an atypical symptom of referred angina pain .
the patient was seen 2 weeks later at the cardiology clinic of our hospital and reported no complaints about her condition or recurrence of ear pain .
an ecg revealed no changes from the previous one done 2 weeks earlier at the time of discharge .
the underlying pathophysiology of the referred otalgia in this patient can be explained by the autonomic dysfunction of the auricular branch of the vagus nerve often termed alderman s nerve .
this branch of the vagus innervates the inner portion of the outer ear , and also controls the skeletal muscles including the superior , middle and inferior pharyngeal constrictors . the sinoatrial ( sa ) node
we suggest that partial occlusion of the rca promoted damage of the parasympathetic fibers of the right vagus , and was the cause of referred otalgia and pharyngitis in our patient .
sensory nerves are affected by type 2 diabetes [ 47 ] , but whether such a preexisting condition predisposes a person to angina - referred otalgia or pharyngitis is not clear . to our knowledge ,
symptoms of ear pain for cad and acute arterial occlusion in a patient have rarely been discussed in the literature .
we found only one report ; in this report the correct diagnosis of cardiac ischemia was missed in two patients who were initially treated for primary ear pain . in conclusion , clinicians should be aware and recognize that ear and throat pain may represent symptoms for cardiac ischemia .

Answer:
a rare case of a patient with unusual symptoms of earache and sore throat for cardiac ischemia is presented .
 a diagnosis of non - st - segment elevation myocardial infarction ( nstemi ) was made based on initial elevation of troponin and an abnormal electrocardiograph ( ecg ) .
 percutaneous coronary intervention ( pci ) performed with stent placement in the occluded coronary vessel was followed by a decrease in troponin level and complete resolution of the ear and throat pain and patient recovery from cardiac ischemia .


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 structures of acl and mcp in the gas phase were optimized at the b3lyp/6 - 31 g * level .
the structures of the water clusters were determined with classical molecular dynamics trajectories ( see details in the si ) .
the cluster models include solvents that have at least one of the atoms within 3 and 4  from acl and mcp , respectively . the geometry of the acl and mcp in the water clusters was further optimized at the b3lyp / cc - pvdz and cam - b3lyp / cc - pvdz levels , respectively . in the optimization ,
the water molecules were fixed at the md structure and replaced by point - charges ( tip3p charges ) .
we also fixed the c atom next to the o atom of acl . in mcp , the atomic coordinates of the central c atom were fixed .
the hf orbitals were transformed into mos localized within each fragment ( solute and solvent ) .
our transformation uses reference orbitals ( rmos ) obtained with external calculations for isolated molecules .
, we show the populations at the fragments . in the perturbation - selection step of the sac - ci calculations , a set of threshold ,  levelfour  ,
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 re - organized for online delivery , but are not copy - edited or typeset . technical support issues arising from supporting information ( other than missing files ) should be addressed to the authors

Answer:
intermolecular interactions regulate the molecular properties in proteins and solutions such as solvatochromic systems . some of the interactions have to be described at an electronic - structure level . in this study ,
 a commutator for calculating the excitation energy is used for deriving a first - order interacting space ( fois ) to describe the environmental response to solute excitation . the fois wave function for a solute - in - solvent cluster
 is solved by second - order perturbation theory .
 the contributions to the excitation energy are decomposed into each interaction and for each solvent .


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:
brown sequard syndrome resulting from compression due to an epidural hematoma is a relatively rare occurrence , more so with a spontaneous history .
she underwent an open door laminoplasty for evacuation of the hematoma . following surgery the patient responded rapidly and currently at 18 months
in the emergency room when a patient is clinically diagnosed as a case of brown sequard syndrome it is important to ask for an mri scan of the cervical spine .
hematoma in the cervical epidural space should be considered in the differential diagnosis of brown sequard syndrome especially in the elderly with history of doubtful trivial trauma .
brown sequard syndrome is an incomplete spinal cord lesion characterized by a clinical presentation reflecting hemi - section of the spinal cord .
this is referred to as ipsilateral hemiplegia and contralateral pain and temperature sensation deficits ( anaesthesia ) .
the most common cause is penetrating trauma such as a gunshot wound or stab wound to the spinal cord , however spinal tumours and blunt trauma to the spine have also been implicated as potential causes .
hematoma is also a cause of brown sequard syndrome but is very rare and usually occurs with predisposing risk factors for bleeding ( anticoagulant therapy , hypertension ) .
brown sequard syndrome as a result of cervical epidural hematoma is a rare entity with only a handful of cases reported in literature .
we describe a case of brown sequard syndrome in a 65 year old female without any underlying risk factors , presenting with sudden onset hemiparesis rapidly progressing to hemiplegia ( within a span of days ) due to a cervical epidural hematoma following a doubtful history of trivial trauma .
a previously healthy 65 year old female presented to us with the complaint of right side hemiplegia without any significant history of trauma . on subsequent inquiry
she gave a history of brisk involuntary hyperextension of the neck following which she developed sudden onset hemiparesis , progressed to hemiplegia within a span of five days .
she did not have a history of any congenital or acquired disorder of coagulation . on elaborate neurological survey
it was found that motor power of the patient s right side upper and lower limb was of grade 0/5 with anesthesia of left side below c3 .
she was evaluated with a cervicodorsal mri scan , which showed a hyper intense space occupying lesion suggesting an epidural hematoma at the c3-c4 level ( fig.1 ) .
the patient was taken up for emergency surgery . with the patient in prone position under general anaesthesia
, a posterior midline incision was taken exposing the tips of the spinous processes from c3 to c5 levels .
two bony gutters were drilled bilaterally at the border of the exposed laminae by means of an air drill . in our case ,
the left side border of the laminae was excised from its cranial to caudal end with a kerison rongeur and the spinous processes and the laminae were pushed laterally as if to open a door , thereby exposing the spinal canal ( hirabayashi s open door laminoplasty ) .
a. t2 weighted transverse section of the cervical cord showing an area of heterogeneous hyper intensity compressing the cord .
b. t1 weighted transverse section of the spine showing an isointense lesion compressing the cord . c. t2 weighted sagittal cut of the cervical spinal cord showing heterogeneous hyper intense signal of the hematoma .
postoperatively the patient was immobilized with a hard cervical collar and physiotherapy ( passive mobilization ) was started .
four months following the surgery the patient regained her motor strength to grade 3/5 with partial return of sensory functions . at twelve months follow up motor power of the affected side improved to grade 5/5 with regaining of normal sensory functions on opposite
about 40% of the cases reported in the literature till date do not have any demonstrable etiology and are therefore referred to as idiopathic spontaneous cervical epidural hematoma .
these need to be differentiated from other well known causes such as neoplasm and systemic diseases , anticoagulant therapy , hypertension or vascular malformations   and pregnancy   for planning of the management and to predict prognosis .
there is controversy regarding the source of the hematoma ; is it arterial or venous ?
the proponents of the venous origin theory maintain that the sudden increase in intra - thoracic and intra - abdominal pressure leads to the rupture of the thin walled epidural veins .
thus during activities like coughing , sneezing , straining during defecation and micturition , vomiting and coitus these thin walled epidural veins may rupture and lead to the generation of the hematoma .
however several authors have pointed out that since the epidural venous pressure is less than the intrathecal pressure , thus these ruptured veins are an unlikely source to produce a hematoma large enough to cause compression of the thecal sac and develope brown sequard syndrome .
after study of the arterial structures of the cervical epidural region it has been hypothesized that extreme movements at the cervicodorsal junction could result in tearing of the arteries .
the high arterial pressure can lead to development of hematoma large enough to cause compression of the dural sac leading to the clinical syndrome of cord compression .
the most common presentation of spontaneous cervical epidural hematoma is acute onset of neck pain , which is usually radiating in nature and the localization depends on the involvement of specific nerve roots .
the second most common symptom is weakness of the limbs below the level of compression .
the weakness gradually increases over days but complete loss of motor power has not been reported and this deficit rarely recovers spontaneously .
mri is the diagnostic tool of choice in spontaneous cervical epidural hematoma . on t2 weighted images the hematoma appears as an area of heterogeneous hyper- intensity of the cord with focal hypo - intense areas . on t1 weighted images the lesion is usually iso - intense in the acute phase ; however chronic hematomas may be hyper- intense .
the treatment of choice in spontaneous cervical epidural hematoma is emergency surgical decompression although a few cases have been reported in literature to have recovered without any surgical intervention .
the procedure of choice is a laminectomy , although a hemi - laminectomy or laminoplasty could be performed depending on the extent and localization of the hematoma .
ispontaneous cervical epidural hematoma leading to a brown sequard syndrome is a rare entity in clinical practice and it has a fatal progressive course in cases where the diagnosis is delayed .
spontaneous cervical epidural hematoma may present as hemiparesis prompting the emergency room physician to make an erroneous diagnosis of cerebrovascular accident , leading to delay in the diagnosis .
prompt diagnosis of the condition and urgent decompression is vital to prevent irreversible damage of the cord .
a thorough clinical examination is a must followed by a mri scan of the cervical spine to exclude this rare entity .
although there have been rare reports of spontaneous recovery , surgical decompression is the preferred modality of treatment . in cases presenting as hemiparesis , sensory examination of opposite side
an mri can delineate the cause and surgical decompression is warrented in cases of spontaneous epidural hematoma that causes neurodeficit .

Answer:
introduction : brown sequard syndrome resulting from compression due to an epidural hematoma is a relatively rare occurrence , more so with a spontaneous history .
 we report one such case.case report : we present a 65yr old female presenting with hemiplegia with contralateral anesthesia .
 magnetic resonance imaging showed a hematoma in the epidural space in the c3-c4 region .
 she underwent an open door laminoplasty for evacuation of the hematoma . following surgery
 the patient responded rapidly and currently at 18 months follow up she is neurologically grade 5/5 with normal sensations.conclusions:in the emergency room when a patient is clinically diagnosed as a case of brown sequard syndrome it is important to ask for an mri scan of the cervical spine .
 hematoma in the cervical epidural space should be considered in the differential diagnosis of brown sequard syndrome especially in the elderly with history of doubtful trivial trauma .


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 prostate - specific antigen ( psa ) level has been an important diagnostic tool for detecting prostate cancer .
it has been shown that an abnormal digital rectal examination ( dre ) has markedly decreased and biochemical findings ( elevated psa ) have increased over the past 20 years for the indication of prostate biopsy .
this means that evaluation of prostate cancer is more and more based on the psa level rather than on suspicious dre
. however , cancer detection rates from biopsy in the presence of isolated psa elevation and a normal dre range between 30% and 40% . also , a high concentration of psa can be found in benign disorders such as benign prostatic hyperplasia ( bph ) , urinary tract infections , and bacterial prostatitis [ 2 - 5 ] .
although it has been reported that acute inflammation is necessary to cause psa elevation , there is growing evidence that subclinical inflammation may also contribute to rises in psa levels [ 6 - 9 ] .
furthermore , several investigators have shown that treatment of chronic prostatitis , when identified , can decrease psa , which suggests that the use of anti - microbial or anti - inflammatory drugs may reduce the number of men who need prostate biopsies .
there is no doubt that symptomatic prostatitis needs to be treated , but uncertainty exists about the appropriate management of asymptomatic patients with elevated psa and normal dre .
the aim of our study was to investigate the possibility of reducing the number of prostate biopsies in patients with a high psa level showing a psa decrease or normalization after antibiotic therapy .
this approach could be useful in patients for whom it is necessary to postpone biopsy and in patients with previous negative biopsies who are willing to avoid biopsy until further psa increase .
this investigation was conducted prospectively among 413 patients with a serum psa level of over 4 ng / ml to under 10 ng / ml from january 2004 to december 2009 .
subjects were excluded if they had been treated by 5-alpha reductase inhibitor for more than 3 months or if they had a history of transurethral resection of the prostate .
the psa level was determined by using immunoenzymatic assay before dre and transrectal ultrasonography ( trus ) to avoid false - positive results . to exclude prostatitis
, all patients underwent the expressed prostatic secretion ( eps ) or voided bladder urine 3 ( vb3 ) test to be classified into two groups .
one group had positive findings on the eps or vb3 test and the other group had negative findings .
a cover slip was placed over the specimen and it was examined under high - power microscopy . a positive finding
was defined as a white blood cell ( wbc ) count higher than 10 in the prostate secretion after eps or wbc higher than 10 in vb3 urine after eps .
the patients with a positive result were treated with quinolone antibiotics for 2 months , and they were asked to return for repeat screening 2 months later . if the psa level was still higher than 4 ng / ml after 2 months , the patients underwent prostate biopsy . in the other cases , the patients avoided prostate biopsy
the subjects underwent at least 10 core biopsies with transrectal ultrasound - guided needle biopsy of the prostate .
chicago , il , usa ) was used for the statistical analysis , and independent t - tests were used for analysis of the characteristics of both groups .
of the 413 men studied , 215 ( 52% ) patients had positive findings on the eps or vb3 test .
of the 215 patients , 53 men avoided prostate biopsy because their serum psa level had decreased to less than 4 ng / ml . the other patients ( 162 of 215 ) still had an elevated serum psa level of more than 4 ng / ml , including 7 in whom the biopsy results revealed cancer .
patients with negative findings on the eps or vb3 test ( 198 of 413 ) underwent prostate biopsy immediately ( fig .
the total prostate cancer detection rate was 11.6% in our subjects , whereas it was 20.7% in the patients with negative findings on the eps or vb3 test and 3.3% in those with positive findings , respectively .
the mean age was significantly different between the positive group ( 65.0 ) and the negative group ( 71.2 ) .
there were no significant differences in the mean initial serum psa level or prostate volume between the groups ( table 1 ) .
since psa was introduced in the 1980s as a variable for detecting prostate cancer , the detection rate of prostate cancer has been increasing .
it is true that an abnormal finding on a dre or trus is an indication for prostate biopsy , but in the majority of cases , the psa level is the most important factor in deciding whether we will proceed with prostate biopsy .
however , it is reported that 30 to 40% of patients who test positive for prostate cancer in prostate biopsy proceeded when only the psa was increased without any abnormality in the dre or trus .
the specificity and sensitivity of psa can result in high values in other positive diseases .
the psa may increase not only in bph but also in urinary tract infection and bacterial prostatitis .
the psa can increase in acute inflammation and silent infection [ 7 - 9,12 ] .
also , some researchers have reported that treatment with antibiotics and anti - inflammatory drugs for chronic prostatitis can decrease the psa and the necessity for prostate biopsy .
nadler et al .   reported that the size and infection of the prostate can be a chief cause of psa increase in the case of patients not diagnosed with prostate cancer .
but irani et al .   reported that even if there is an infiltration of inflammatory cells in the prostatic interstitium , it is not related to the psa increase in the blood if the glandular epithelial cell layer is not destroyed at the same time .
furthermore , it has been reported that the existence of inflammatory cells of the interstitium or glandular tissue in the prostate biopsy has no statistical affiliation with the concentration of psa in the blood .
carver et al .   argued that national institutes of health ( nih ) category iv asymptomatic prostatitis increases the psa concentration in the blood , but its clinical significance is not that greatbecause the mean differences with the normal group are 2.3 ng / ml and 1.4 ng / ml , respectively .
reported that there is an increase of the concentration of psa in the blood in 71% of patients with acute prostatitis , 15% of patients with chronic prostatitis , and 6% of patients with nonbacterial prostatitis , but there was no psa increase in patients who showed only symptoms of chronic prostatitis .
found a relation of the psa concentration in the blood with acute and chronic prostatitis accompanied by clinical symptoms identified histologically , but no relation in the case of deactivated prostatitis .
chang et al .   investigated 223 patients who tested negative in a prostate biopsy by classifying the infection level and reached the conclusion that the whole size of the prostate is an important factor that contributes to the increase in the psa concentration in the blood , but that there was no relation with the prostatitis level .
the relationship of prostatitis and the psa increase continues to stimulate dispute , and we suggest that the findings mentioned above are not sufficient to explain the reason for the psa increase in the case of nih category iv asymptomatic prostatitis .
nadler et al .   investigated 421 patients with nih category iii chronic prostatitis and reported recently that the mean psa concentration in the blood of the patients investigated was 1.97 ng / ml . compared with the level in the normal group of 1.72 ng / ml , this was a statistically significant increase , but it is still below the normal psa range .
also , f - psa , percent f - psa , and the [ -2 ] ppsa isoform show some increase with prostate cancer , but they are inappropriate to be used as biomarkers of prostate cancer diagnosis because of their low specificity and sensitivity .
treatment with antibiotics in the case of chronic prostatitis and increased psa results in a very significant psa decrease .
but any special bacteria is found in 90% of cases of prostatitis with or without symptoms .
this kind of investigation of the changes in psa after treatment with antibiotics or anti - inflammatory drugs for nonbacterial prostatitis is uncommon . according to the report of potts   among 122 patients with an average psa increase of 9.35 ng / ml , 51 ( 42% ) patients
were diagnosed with infection by urinalysis after a massage of the prostate or prostatic secretion ( eps ) .
the patients were then treated with antibiotics for 4 weeks , and after 6 to 8 weeks they had a psa examination .
after the treatment , 22 of the 51 patients had a normal psa concentration ( average , 2.9 ng / ml ) and they did not need a prostate biopsy .
but there was a continuous increase of psa in the remaining 29 patients , and among them , 9 patients were diagnosed with prostate cancer . in comparison with patients diagnosed with cancer in prostate biopsy after treatment with antibiotics ,
the psa decrease in patients with benign biopsy results was significantly greater ( -1.3% vs. -21.3% ) . in the investigation carried out with 95 patients diagnosed with nonbacterial prostatitis and who showed an increase of psa , bozeman et al
.   proceeded with prostate biopsy in patients in whom the psa value did not decrease after 4 weeks of treatment with antibiotics and anti - inflammatory drugs . among these ,
the psa of 36.4% of patients decreased from 8.48 ng / ml to 5.39 ng / ml after treatment ; in 44 patients ( 46.3% ) the psa decreased below 4 ng / ml , so they avoided prostate biopsy . in the remaining patients who underwent prostate biopsy , 13 patients ( 25.5% )
were diagnosed with prostate cancer , 37 patients ( 72.5% ) with chronic infection , and 1 patient ( 1.05% ) with bph . among the patients diagnosed with prostate cancer , just 4.8% of patients had shown a psa decrease from 8.32 ng / ml to 7.92 ng / ml , which was not statistically significant .
therefore , the authors argued that chronic prostatitis is the chief cause of psa increase and that treatment for prostatitis can decrease unnecessary prostate biopsy .
but hochreiter   argued that although the authors of two investigations considered that the patients were not diagnosed with prostate cancer because the psa was decreased to less than 4 ng / ml , it was difficult to conclude that the patients in fact had no cancer .
it is not a certainty that psa - normalized patients are cancer free after antibiotic therapy .
there are no general guidelines that can be applied to all men with increased psa before prostate biopsy . in cases
in which the psa level is increasing , if we first exclude prostatitis and carry out a serial diagnostic procedure , it may help to reduce unnecessary prostate biopsy .

Answer:
purposewe aimed to reduce unnecessary prostatic biopsy in patients with high prostate - specific antigen ( psa ) by consideration of prostatic inflammation.materials and methodsthe investigation was conducted prospectively in 413 patients with a psa level of 4 to 10 ng / ml from january 2004 to december 2009 .
 all patients underwent the expressed prostatic secretion ( eps ) or voided bladder urine 3 ( vb3 ) test to be classified into two groups : positive group and negative group .
 patients with a positive result on the eps or vb3 test were treated with antibiotics for 2 months , and in cases in which the psa level remained high , we performed prostate biopsy . in patients with a negative result on the vb3 test , we performed prostate biopsy directly.resultsof the 413 study patients , 215 ( 52% ) patients had positive findings on the eps or vb3 test .
 after 8 weeks of antibiotics therapy , 53 of the 215 men avoided prostate biopsy because their psa level was normalized .
 the other patients ( 162 of 215 ) still had elevated psa levels of more than 4 ng / ml , including 7 patients in whom the biopsy revealed cancer .
 patients with negative findings ( 198 of 413 ) underwent prostate biopsy .
 of the 198 patients , 41 were diagnosed with prostate cancer .
 the total prostate cancer detection rate was 11.6% in our subjects , where as it was 20.7% in the patients with negative findings on the eps or vb3 and 3.3% in the patients with positive findings , respectively.conclusionsin cases in which the psa level is increasing , if we first exclude prostatitis and carry out a serial diagnostic procedure , it may help to reduce unnecessary prostatic biopsy .


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:
graphene oxide ( go ) solution was synthesized from natural graphite powder by a modification of hummers method.45 cu2o / rgo composites were fabricated by a microwave - assisted hydrothermal reaction .
firstly , cu(no3)2 was added to a mixture of ethanol and water in the ratio of 64:36 .
then , a calculated amount of go solution and formic acid ( 3 ml ) were added . for optimization , cu2o / rgo composites with different amounts of rgo
were also synthesized , which include cu2o/0.25 % rgo , cu2o/0.5 % rgo , and cu2o/1 % rgo , in which x % represents the calculated weight ratio of the go added to cu2o . after stirring for 2 h ,
the homogeneous solution was heated with stirring in the microwave system at 150 c for 3 h. after the product was cooled to rt , the final product was collected by centrifugation , washed with water five times , and dried at 70 c .
blank cu2o was synthesized through the same procedure , except for the addition of go solution .
xrd was performed by using a rigaku rint 2100 diffractometer at a voltage of 40 kv .
the morphologies of the products were characterized by field - emission scanning electron microscopy ( fesem , jeol-6701f ) and tem ( jeol-2010f ) .
uv / vis spectra were recorded by using a shimadu uv / vis 2550 spectrophotometer .
pl emission spectra were measured at rt by using a fluorescence spectrophotometer ( f-4500 , hitachi ) .
photocatalyst ( 5 mg ) and nafion solution ( 10 l , 5 wt % ) were dispersed in a water / isopropanol mixture ( 1 ml , 3:1 v / v ) by at least 30 min sonication to form a homogeneous catalyst colloid . for the measurements ,
the catalyst colloid ( 100 l ) was deposited onto an area of approximately 1 cm of the fto conductive glass to form the working electrode .
a pt wire was used as a counter electrode , and an ag / agcl electrode was the reference electrode in the three - electrode photo - electrochemical system .
eis were recorded under an alternating current perturbation signal of 10 mv over the frequency range of 1 mhz to 100 mhz .
the potential ranged from 1.0 to 0 v with a potential step of 10 mv at a frequency of 1 khz .
the co2 reduction reaction was performed in batches by using a septum - sealed glass chamber with a volume of 120 ml , which was heated at 160 for 1 h prior to measurement . to remove possible trace organic contaminants ,
photocatalysts were treated at 200 c for 3 h in a tubular furnace under the protection of ar or in air ( denoted cu2o treated in ar or air ) .
a typical photocatalytic experiment was conducted by using 0.5 g of photocatalysts and 3 ml of deionized water in a co2-purged 120 ml reactor .
excess ( 0.7 m ) sodium sulfite was added to each batch as a hole scavenger.15 , 46 a 150 w xe lamp ( newport ) was used as a light source .
the light output was measured by using a newport 1918-r high - performance optical power meter fitted with a newport 918-d calibrated photodetector equipped with an integrated attenuator .
the reaction product was monitored by periodical sampling of the gas phase from the glass chamber by using a gas - tight syringe and analyzed by gc ( varian gc-450 ) with a thermal conductivity detector ( tcd , connected to a molecular sieve column ) to detect h2 , o2 , and n2 and a flame ionization detector ( fid , connected to a cp - sil 5cb capillary column ) to detect hydrocarbons .
a methanizer was installed to enable the fid to detect co with 1000 higher sensitivity . for the isotope - tracer experiment ,
after the addition of cu2o / rgo ( 0.5 g ) into co2-saturated water ( 10 ml ) , the septum - sealed reactor was purged by ar gas for 10 min .
the sample was irradiated with a 150 w xe lamp for 30 min , and then 0.5 ml of the reaction product taken from the vessel headspace was analyzed by gc
graphene oxide ( go ) solution was synthesized from natural graphite powder by a modification of hummers method.45 cu2o / rgo composites were fabricated by a microwave - assisted hydrothermal reaction .
firstly , cu(no3)2 was added to a mixture of ethanol and water in the ratio of 64:36 .
then , a calculated amount of go solution and formic acid ( 3 ml ) were added . for optimization , cu2o / rgo composites with different amounts of rgo
were also synthesized , which include cu2o/0.25 % rgo , cu2o/0.5 % rgo , and cu2o/1 % rgo , in which x % represents the calculated weight ratio of the go added to cu2o . after stirring for 2 h ,
the homogeneous solution was heated with stirring in the microwave system at 150 c for 3 h. after the product was cooled to rt , the final product was collected by centrifugation , washed with water five times , and dried at 70 c .
blank cu2o was synthesized through the same procedure , except for the addition of go solution .
xrd was performed by using a rigaku rint 2100 diffractometer at a voltage of 40 kv .
the morphologies of the products were characterized by field - emission scanning electron microscopy ( fesem , jeol-6701f ) and tem ( jeol-2010f ) .
uv / vis spectra were recorded by using a shimadu uv / vis 2550 spectrophotometer .
pl emission spectra were measured at rt by using a fluorescence spectrophotometer ( f-4500 , hitachi ) .
photocatalyst ( 5 mg ) and nafion solution ( 10 l , 5 wt % ) were dispersed in a water / isopropanol mixture ( 1 ml , 3:1 v / v ) by at least 30 min sonication to form a homogeneous catalyst colloid . for the measurements ,
the catalyst colloid ( 100 l ) was deposited onto an area of approximately 1 cm of the fto conductive glass to form the working electrode .
a pt wire was used as a counter electrode , and an ag / agcl electrode was the reference electrode in the three - electrode photo - electrochemical system .
eis were recorded under an alternating current perturbation signal of 10 mv over the frequency range of 1 mhz to 100 mhz .
the potential ranged from 1.0 to 0 v with a potential step of 10 mv at a frequency of 1 khz .
the co2 reduction reaction was performed in batches by using a septum - sealed glass chamber with a volume of 120 ml , which was heated at 160 for 1 h prior to measurement . to remove possible trace organic contaminants ,
photocatalysts were treated at 200 c for 3 h in a tubular furnace under the protection of ar or in air ( denoted cu2o treated in ar or air ) .
a typical photocatalytic experiment was conducted by using 0.5 g of photocatalysts and 3 ml of deionized water in a co2-purged 120 ml reactor .
excess ( 0.7 m ) sodium sulfite was added to each batch as a hole scavenger.15 , 46 a 150 w xe lamp ( newport ) was used as a light source .
the light output was measured by using a newport 1918-r high - performance optical power meter fitted with a newport 918-d calibrated photodetector equipped with an integrated attenuator .
the reaction product was monitored by periodical sampling of the gas phase from the glass chamber by using a gas - tight syringe and analyzed by gc ( varian gc-450 ) with a thermal conductivity detector ( tcd , connected to a molecular sieve column ) to detect h2 , o2 , and n2 and a flame ionization detector ( fid , connected to a cp - sil 5cb capillary column ) to detect hydrocarbons .
a methanizer was installed to enable the fid to detect co with 1000 higher sensitivity .
after the addition of cu2o / rgo ( 0.5 g ) into co2-saturated water ( 10 ml ) , the septum - sealed reactor was purged by ar gas for 10 min .
the sample was irradiated with a 150 w xe lamp for 30 min , and then 0.5 ml of the reaction product taken from the vessel headspace was analyzed by gc
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 re - organized for online delivery , but are not copy - edited or typeset . technical support issues arising from supporting information ( other than missing files ) should be addressed to the authors

Answer:
a facile one - step microwave - assisted chemical method has been successfully used for the synthesis of cu2o / reduced graphene oxide ( rgo ) composites .
 photocatalytic co2 reduction was then investigated on the junction under ambient conditions .
 the rgo coating dramatically increases cu2o activity for co2 photoreduction to result in a nearly six times higher activity than the optimized cu2o and 50 times higher activity than the cu2o / ruox junction in the 20th hour .
 furthermore , an apparent initial quantum yield of approximately 0.34 % at 400 nm has been achieved by the cu2o / rgo junction for co2 photoreduction .
 the photocurrent of the junction is nearly double that of the blank cu2o photocathode .
 the improved activity together with the enhanced stability of cu2o is attributed to the efficient charge separation and transfer to rgo as well as the protection function of rgo , which was proved by xrd , sem , tem , x - ray photoelectron spectroscopy , photo - electrochemical , photoluminescence , and impedance characterizations .
 this study further presents useful information for other photocatalyst modification for efficient co2 reduction without the need for a noble - metal co - catalyst .


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:
due to the widespread use of imaging modalities , such as ultrasonography , computed tomography ( ct ) , and magnetic resonance imaging , the incidences of incidentally found small cortical renal masses ( srms ) and renal cell carcinoma ( rcc ) , have increased during the past years . for decades , the standard therapy for patients with clinically suspected rcc consisted of radical nephrectomy , an invasive surgical procedure with high morbidity .
however , in a recently published randomized trial of nephron - sparing surgery ( nss ) in patients with srm yielded comparable oncological outcome with radical nephrectomy . in addition
, population - based studies clearly demonstrate an overall survival benefit in patients undergoing nss as a result of preserved renal function [ 4 , 5 ] .
nephron - preserving procedures , such as partial nephrectomy and image - guided minimally invasive ablative procedures , have therefore increasingly been applied in patients with srm [ 6 , 7 ] .
initially , image - guided ablative procedures were performed in patients who were not suitable candidates for nss based on significant medical comorbidity , advanced symptomatic disease , or refusal of conventional therapy [ 6 , 8 ] .
accumulating data on follow - up and oncological safety suggest a broader indication in patients with srm .
a particular form of an image - guided ablative procedure is radiofrequency ablation ( rfa ) , which can be performed open or percutaneously . in rfa , an electric current oscillates through an electrode placed centrally in the target tissue .
this results in frictional ionic agitation and heat formation in the tissue surrounding the tip of the electrode , causing local protein coagulation and cellular death . compared with open and laparoscopic ( partial ) nephrectomy
it is a nephron - sparing therapy with low morbidity and mortality , short hospital stay , and acceptable oncologic outcome [ 8 , 10 , 12 ] .
nevertheless , rfa of the kidney can be accompanied by minor and even major complications .
several investigators have postulated the occurrence of bowel perforation as a complication of rfa of renal masses due to the close proximity of bowel [ 13 , 14 ] . to our current knowledge ,
only two articles have described such a case [ 15 , 16 ] . yet in a large series of 100 percutaneously performed renal rfas , none of the patients had colonic injuries .
the reported incidence of bowel perforation complicating renal rfa therefore ranges from 0 to 8.3% [ 8 , 15 ] . in this article
, we describe the first case of appendiceal perforation as a complication of ct - guided percutaneous rfa of an smr .
a 60-year - old male patient was referred to our outpatient clinic with an incidental mass in the right kidney , which was recently diagnosed during work - up of his microscopic hematuria .
his previous medical history consisted of kidney stone lithotripsy , hypertension treated with a beta - blocker and diuretic , and two episodes of transient ischemic attack .
abdominal ct scan showed a rapidly enhancing , exophytic mass in the lower pole of the right kidney with a maximum diameter of 2.5  cm ( fig .
the appendix was noticed in a retrocecal position , at a 1.4-cm distance from the renal mass ( fig .
1b , c ) . based on his mild comorbidity and on the small size of the renal mass ,
1a small , exophytic , rapidly enhancing renal mass at the lower pole of the right kidney .
b retrocecal position of the appendix on the lateral site of the right kidney in the vicinity of the renal mass ( c ) .
* appendix , renal mass a small , exophytic , rapidly enhancing renal mass at the lower pole of the right kidney .
b retrocecal position of the appendix on the lateral site of the right kidney in the vicinity of the renal mass ( c ) .
* appendix , renal mass our technique of rfa in renal masses has extensively been described in previous articles [ 17 , 18 ] . in short ,
after the patient received an antibiotic prophylaxis ( 1,500  mg cefuroxim ) and epidural analgesic before the rfa procedure , he was placed in prone position on the ct table .
a planning ct scan was performed to locate the renal mass . under fluoroscopic ct guidance ,
a 17 g cool - tip electrode ( valleylab , covidien , boulder , co ) was placed centrally into the mass .
subsequently a 20 g needle was inserted lateral in the anterior pararenal space for injection of dextrose in water to hydrodissect the renal mass from the surrounding vital tissues , such as the colon and appendix . after the hydrodissection and
the positions of the needles were checked with a ct scan of the area of interest , ablation was started .
final temperature after 15  min was  > 75c with adequate roll - offs .
the rfa procedure was performed by a highly experienced interventional radiologist ( w.p . ) who at that time had already performed  > 180 percutaneous image - guided ablative procedures ( including renal , liver , and lung ) .
a 60-year - old male patient was referred to our outpatient clinic with an incidental mass in the right kidney , which was recently diagnosed during work - up of his microscopic hematuria .
his previous medical history consisted of kidney stone lithotripsy , hypertension treated with a beta - blocker and diuretic , and two episodes of transient ischemic attack .
abdominal ct scan showed a rapidly enhancing , exophytic mass in the lower pole of the right kidney with a maximum diameter of 2.5  cm ( fig .
the appendix was noticed in a retrocecal position , at a 1.4-cm distance from the renal mass ( fig .
1b , c ) . based on his mild comorbidity and on the small size of the renal mass ,
1a small , exophytic , rapidly enhancing renal mass at the lower pole of the right kidney .
b retrocecal position of the appendix on the lateral site of the right kidney in the vicinity of the renal mass ( c ) .
* appendix , renal mass a small , exophytic , rapidly enhancing renal mass at the lower pole of the right kidney .
b retrocecal position of the appendix on the lateral site of the right kidney in the vicinity of the renal mass ( c ) .
our technique of rfa in renal masses has extensively been described in previous articles [ 17 , 18 ] . in short ,
after the patient received an antibiotic prophylaxis ( 1,500  mg cefuroxim ) and epidural analgesic before the rfa procedure , he was placed in prone position on the ct table .
a planning ct scan was performed to locate the renal mass . under fluoroscopic ct guidance ,
a 17 g cool - tip electrode ( valleylab , covidien , boulder , co ) was placed centrally into the mass .
subsequently a 20 g needle was inserted lateral in the anterior pararenal space for injection of dextrose in water to hydrodissect the renal mass from the surrounding vital tissues , such as the colon and appendix .
after the hydrodissection and the positions of the needles were checked with a ct scan of the area of interest , ablation was started .
final temperature after 15  min was  > 75c with adequate roll - offs .
the rfa procedure was performed by a highly experienced interventional radiologist ( w.p . ) who at that time had already performed  > 180 percutaneous image - guided ablative procedures ( including renal , liver , and lung ) .
on the ct images performed during the procedure , the colon and appendix were considered to be a safe distance ( at least 1.0  cm ) from the ablative field as a result of the hydrodissection ( fig .  2 ) .
adequate ablation of the kidney tumor was achieved without intraprocedural complications . on the first postprocedural day
fluid collection with air configuration on the lateral and anterior side of the renal mass as a result of hydrodissection can be seen .
retrocecal appendix ( * ) is in the vicinity of the ablative field patient in left lateral decubitus position during rfa procedure .
fluid collection with air configuration on the lateral and anterior side of the renal mass as a result of hydrodissection can be seen .
retrocecal appendix ( * ) is in the vicinity of the ablative field five days after the procedure , he presented at our hospital with fever ( 39.5c ) and right lumbar pain .
3 ) showed a large retroperitoneal fluid collection with air configurations , suggesting retroperitoneal abscess formation , on the lateral side of the right kidney .
moreover , a direct connection was noticed between the cecum and fluid collection , with contrast material in the retroperitoneal abscess , suggesting perforation at the base of the appendix ( fig .  3 ) .
after ct - guided drainage of the abscess and intravenous antibiotic therapy , the patient remained septic . therefore , 2  days later laparotomy was performed .
intraoperatively , a retroperitoneally confined abscess was drained . however , due to an extensive local inflammatory reaction affecting the terminal ileum ( fig .
4 ) , the approach had to be extended intra - abdominally to allow necessary resection of the ileocecal region followed by primary anastomosis between the ileum and ascending colon and an omental plasty . during this step ,
histopathologic examination of the resected specimen showed a perforated appendix based on ulcero - phlegmonous and gangrenous inflammation . on day 18 after the rfa
3leakage of contrast material from the perforated cecum / appendiceal base into the right anterior pararenal space suggesting appendiceal perforation . presence of air configurations in the right anterior pararenal space suggesting abscess formationfig .
oversewn cecal perforation at the base of the necrotic appendix leakage of contrast material from the perforated cecum / appendiceal base into the right anterior pararenal space suggesting appendiceal perforation .
presence of air configurations in the right anterior pararenal space suggesting abscess formation intraoperative view after abscess drainage .
rfa of srm was first applied in 1997 and has proven to be a promising and safe technique since . in a large series of 100 patients with renal tumors treated with rfa , 11 minor and major complications were reported , of which the most common was haemorrhage .
. complications of rfa can generally be divided into two categories : ( 1 ) those related to imaging - guided electrode placement and ( 2 ) those related to thermal therapy .
the latter are more common in kidney rfa compared with other rfa indications , e.g. , hepatic rfa , as a result of the proximity of other vital structures , such as the bowel and ureter . nevertheless , only two articles so far have reported bowel perforation as a complication of renal rfa [ 15 , 16 ] .
the first step in preventing thermal complications is thorough assessment of the tumor location on preprocedural ct scans during the process of patient selection .
percutaneous renal rfa can be performed with the patient prone or in lateral decubitus position . in both positions ,
vital structures in the vicinity of the target mass will be kept away from the ablative zone by way of gravity .
third , the rfa electrodes can be used to lift the ablated tumor away from vital structures .
examples of invasive methods include hydrodissection with glucose in water or injection of carbon dioxide in between the target tissue and the tissue that needs protection . in our patient ,
a lateral dissection was performed with glucose in water to dissect the renal mass from the appendix and the colon , which was located caudolateral with respect to the renal mass .
unfortunately , in this way the appendix came even closer to the tract of the needle .
nevertheless , on the ct images performed during the procedure , the appendix was considered to be at sufficient distance from the ablative field .
eventually , this caused the appendiceal perforation . since this complication , we modified our ablative technique .
currently we start the hydrodissection before placement of the rfa electrode in the target tissue . in addition , instead of injecting 100  cm fluid during hydrodissection , we attach the needle to a continuous drip system .
in conclusion , in this article we described a case of appendiceal perforation leading to retroperitoneal abscess formation as a complication of percutaneous rfa of an srm .
although rfa of srm is generally a minimally invasive and safe procedure , one should be aware of the possibility of particular minor and major complications when performing this innovative and promising procedure .
if vital structures remain in close vicinity of the ablative field , one should consider treatment options other than rfa .

Answer:
percutaneous radiofrequency ablation ( rfa ) has gained wide acceptance as nephron - sparing therapy for small renal masses in select patients . generally , it is a safe procedure with minor morbidity and acceptable short - term oncologic outcome .
 however , as a result of the close proximity of vital structures , such as the bowel , ureter , and large vessels , to the ablative field , complications regarding these structures may occur .
 this is the first article describing appendiceal perforation as a complication of computed tomography - guided rfa despite hydrodissection . when performing this innovative and promising procedure one should be aware of the possibility of particular minor and even major complications
 .


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:
neoadjuvant chemotherapy actually takes an important place in treatment of operable breast cancer in the hope of improving conservative surgery rate of female patients .
neoadjuvant chemotherapy includes today on target therapies involving the research on expression of specific molecules by tumoral cells . in routine practice , estrogen receptors ( er )
, progesterone receptors ( pr ) , and human epidermal growth factor receptor 2 ( her2 ) are the common used biomarkers .
new pharmaceutical molecules , other than er / pr or her2 , are now already evaluated in clinical research as new biomarkers and new target for neoadjuvant therapy .
fine - needle aspiration cytology ( fnac ) of the breast is wellknown as a safe , effective , economical , and accurate technique for diagnosing palpable breast lesion [ 24 ] .
this last decade , fnac technique is improved by the development of new cytological methods allowing standardization of fixation and assuring constant results with ancillary tests such as immunocytochemistry and in situ molecular biology .
also , one of the advantages of fnac is the management of small tissue fragments permitting a repetitive evaluation of the chronological evolution in expression of tumoral biomarkers .
previously , the role of fnac has been challenged by results obtained with cnb that seems more robust than fnac . in general ,
nevertheless , cnb carries disadvantage in terms of a long tissue processing time and patient discomfort such as pain ( 1.7% to 3.7% ) , hematoma ( 0.72% ) , and very rarely pneumothorax [ 6 , 7 ] .
fnac includes more advantages than cnb such as minimal invasiveness and minimal discomfort ( more painless ) that could be interesting for aged or frailty patients with comorbidities . in palpable lesions ,
fnac could perform repetitively and is a serious candidate for the chronological followup of neoadjuvant chemotherapy response .
an important quality of fnac is its ability to give rapid diagnostic information equivalent to that of frozen sections . in our experience
, the result of rapid fnac prior to cnb improves the quality of cnb and gives an immediate diagnosis decreasing anxiety of patient .
other indications of fnac are staging of multiple tumors or suspicious zones and apparition of a new suspicious lesion during neoadjuvant chemotherapy .
finally , fnac could be an excellent alternative when radiographic screening of breast is not available .
table 1 compares the main advantages and disadvantages of fnac versus cnb .
 other clinical fnac indications .

palpable breast lesion.rapid diagnosis to decrease anxiety of patient.patient with morbidity ( senile , cardiac , diabetic etc.).clinical staging : multiple lesions , suspicious lymph node , and so on .
apparition of new lesion in patient treated for breast cancer.evaluation of biomarkers.evaluation of biomarker changes following time or metastasis . when cnb technique is not available .

evaluation of biomarker changes following time or metastasis .   when cnb technique is not available .
it is well known that the combination of clinical evaluation , mammography , and fnac , called triple diagnosis , gives a precise diagnosis [ 10 , 11 ] .
yu et al .   recently demonstrated in meta - analysis of 46 studies that fnac had a sensitivity of 92.7% and a specificity of 94.8% except the unsatisfactory samples .
the roc curve showed an excellent area under the curve of 0.986 , presenting a high level of accuracy . on the other hand ,
if the fnac result was negative , the probability of breast cancer is approximately 8% .
these authors concluded that fnac was an accurate material for evaluation on breast malignancy if rigorous criteria are used .
also , they said that fnac may provide a favourable screening method and permit an improvement of treatment planning .
therefore , when fnac is unsatisfactory , cnb is required to minimize the probability of a missed malignant diagnosis . in a study of fnac and immediate diagnosis performed in 408 palpable breast lesions , liew et al . in 2010
reached the same conclusions : 98.1% sensitivity , 89.5% specificity , and 95.8% accuracy . in 508 cnb followed by jackman et al .
, the rate of false negative for all lesions was 4.4% , for microcalcifications alone 1.2% , and for tumoral mass 0.8% .
these results of cnb are quasi - identical to those obtained with the satisfactory fnac .
most of false negative fnac results of sampling error or discordance between clinical and histological observations [ 6 , 14 ] . in a comparison between cnb and repeat fnac after an indeterminate diagnosis with fnac , kooistra et al .
suggested that cnb should be performed after an indeterminate fnac to obtain a reliable preoperative diagnosis .
other authors concluded that , although the fnac is easier to perform , this technique was not efficient for small and nonpalpable lesions or diagnosis of microcalcifications as those for in situ carcinoma .
these comments are likely true because some preneoplastic lesions are associated with slight cell atypia .
however , bilous   emphasized that cnb shows also problems with similar lesions such as atypical proliferative lesions ( atypical ductal hyperplasia , in situ lobular neoplasia , etc . ) , cellular fibroepithelial lesions , papillary tumors , mucinous carcinoma , radial scar , spindle cell lesions .
moreover , fnac interpretation requires serious experience of the cytopathologist and they think that this is one of the main reasons that overall cnb is to be preferred .   a recent japanese study   of 5693 fnac and 7 different laboratories illustrated a great variability between the institutions suggesting likely difference between education of cytologists and the lack of clinical or radiological information ( triple diagnosis ) .
these last years a new cytological technique , called liquid - based cytology ( lbc ) , has been developed and approved by the food and drug administration .
briefly , lbc standardises the cell fixation , concentrates epithelial cells , and discards blood cells and/or cell debris that obscure the smear .
the efficiency of lbc in the breast cytology has been demonstrated by numerous publications .
the main advantage of lbc is surely to adjunct ancillary tests such as immunocytochemistry , flow cytometry , or molecular biology [ 1820 ] .
compared the er and pr statuses from fnac ( immunocytochemistry ) and cnb ( immunohistochemistry ) , both performed on surgical breast tumors .
they found that both methods give similar results with a concordance between the 2 tests of 98% for er ( with kappa correlation score = 0.93 ) and 96% for pr ( kappa = 0.91 ) .
.   demonstrated similar data in a comparative study between primary breast tumours and their metastasis .
interestingly , the concordance between these both localisations was 81% for er , 65% for pr , and 71% for her2 , suggesting a possibility of biological difference between primary tumors and their metastasis .
other publications showed a long - time storage at 20c and 80c at least 6 months without significant loss of immunoreactivity of pr and ep from breast fnac .
the cell block cytology is an attractive cytological method for ancillary techniques or long - time cell conservations and consists in putting cells of fnac directly in formol fixative fluid identically at a classical histology ( figures 1 and 2 : er , her2 and fish on cell block cytology ) . briefly , after centrifugation to concentrate cells , the pellet was embedded in a synthetic polymer gel that is then processed in paraffin block that could be cut at 4  m , as classical biopsy slides . with this technique , ferguson et al .
found a concordance rate of 95% for er , 90% for pr , and 88% for her2 .
similar results were observed by shabaik et al .   with high specificity ( 100% for both ) and lower sensibility ( 85% and 80% resp .
for er and pr ) . finally , in fnac , false negative er or pr immunostaining exists but false positive tests are very unlikely .
false negative immunohistochemical results are also observed in cnb : in a retrospective study , seferina et al .
calculated a rate of false negative of 26.5% and a rate of false positive of 63.8% for both er and pr . for her2 , they showed 5.4% for false negative rate and 50% for false positive rate .
nevertheless , in our experience , this discordance is often associated with the manipulation of cnb before the fixation ( crush artefacts ) or with a defect of fixation as desiccation .
fortunately the concordance with molecular biology by hybridisation in situ using fish , cish , and sish is very good and can help when her2 is uncertain [ 6 , 25 , 27 ] .
the fish is accurate for lbc cytology [ 22 , 25 , 28 , 29 ] .
the extraction of mrna or dna is also feasible from lbc and fnac , allowing all gene expression analyses [ 2932 ] . in our experience ,
the clinical staging and preoperative lymph node status are important for the evaluation of eligible patient to neoadjuvant therapy . in the axillary lymph node fnac , chang et al .
fnac in lymph node is a cost effective and safe method , false positive is virtually non - existent , and false negative can occur when lymph node is partially involved such as by micrometastase , or isolated tumor cells .   in our experience
, we improve axillary lymph node fnac / lbc by immunocytochemistry using cytokeratin antibody .
thus , axillary fnac plays a role in staging of advanced cases for systemic and neoadjuvant therapy and in evaluating candidates for sentinel lymph node surgical procedure or axillary lymph node dissection .
despite the fact that cnb has been progressively replaced by fnac in the investigation of nonpalpable lesions or microcalcifications without a clinical or radiological mass lesion , fnac has yet a role in palpable lesions in the triple diagnosis association and performed by experienced cytologists . in these conditions , fnac is a safe , effective , economical , and accurate technique for breast cancer evaluation .
recently , cytological methods using lbc technology , associated or not with the cellblock cytological technique , improve immunocytological and molecular tests with the same efficiency as classical histology .
if the limits of its indications are well known , fnac still plays a role in the modern oncological practice .

Answer:
despite the fact that cnb has been progressively replaced by fnac in the investigation of nonpalpable lesions or microcalcifications without a clinical or radiological mass lesion , fnac has yet a role in palpable lesions provided it is associated with the triple diagnosis and experienced cytologist . in these conditions
 , fnac is a safe , effective , economical , and accurate technique for breast cancer evaluation .
 numerous literature reviews and meta - analyses illustrated the advantages and disadvantages of both methods cnb and fnac .
 the difference does not seem significant when noninformative and unsatisfactory fnac was excluded .
 recently , cytological methods using liquid - based cytology ( lbc ) technology improve immunocytological and molecular tests with the same efficiency as classical immunohistochemistry .

 the indications of fnac were , for palpable lesions , relative contraindication of cnb ( elderly or frailty ) , staging of multiple nodules in conjunction or not with cnb , staging of lymph node status , newly appearing lesion in patient under neoadjuvant treatment , decreasing of anxiety with a rapid diagnosis , evaluation of biomarkers and new biomarkers , and chronological evaluation of biomarker following the neoadjuvant therapy response .


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:
patients who present to the emergency department with chest pain require rapid triage , evaluation and management .
myocardial infarction with st segment elevation ( ste ) on electrocardiography ( ecg ) is a common presentation in emergency rooms across the world .
acute coronary syndrome ( acs ) marked by ste on the ecg warrants consideration for emergent cardiac catheterization and possible percutaneous coronary intervention ( pci ) .
in fact , there are now core measures and quality metrics in place that grade a hospital 's efficiency at caring for such patients .
however , the time pressure to optimize such quality metrics may lead to an unintended rush to treatment prior to adequate evaluation . in this report
, we present a rare case where myocardial infarction was seen as a presenting feature of an underlying hematologic disease , thrombotic thrombocytopenic purpura ( ttp ) .
this case highlights the importance of a thorough , yet efficient , clinical evaluation in which the history , physical exam , ecg and laboratory data were needed to make the appropriate triage decision and not miss an unusual diagnosis .
a 48-year - old woman with no known coronary risk factors was transferred from an outside facility to the cardiac catheterization laboratory of our hospital with the diagnosis of ste myocardial infarction for primary pci .
on arrival to our catheterization laboratory , the ecg from the referring hospital showed sinus tachycardia with normal axis and intervals .
there was ste in leads i , ii , avl , v46 and reciprocal st segment depression in lead iii [ figure 1 ] .
laboratory data were not yet available . however , the patient 's history of present illness was significant for malaise , fever , chills and lethargy that began 3 days prior to hospitalization . further questioning
established that she had mild generalized abdominal pain and one episode of non - bloody diarrhea .
the family also noted that she had been intermittently confused and was talking gibberish . on the morning of admission
, she had severe chest pain associated with nausea , vomiting and dyspnea on exertion , which led her to seek medical care .
sinus tachycardia at 121 beats per minute with st segment elevation in lead i , ii , avl , v46 on examination , she appeared toxic and in respiratory distress .
vital signs revealed a blood pressure of 126/70 mmhg with a heart rate of 121 beats per minute .
in addition , mottling of her skin and livedo reticularis over the thighs was noted .
there were a few purpuric skin lesions observed in her antecubital fossa and upper arms .
her jugular venous pressure was elevated up to the angle of the jaw . cardiac exam revealed a normal first and second heart sound along with a fourth heart sound .
peripheral pulses were not palpable in the feet and were only faintly palpable in the arms .
neurologically , she was somewhat confused , but the sensory and motor exam was essentially normal . given that the patient was not having active chest pain , the history was inconsistent with acs and she appeared more toxic than expected for a lateral wall myocardial infarction ; cardiac catheterization was deferred and emergent laboratory studies were obtained .
initial laboratory studies revealed a white blood cell count of 13.5  10/mm ; hematocrit of 24% ; mean corpuscular volume of 88.4 fl and platelet count of 6  10/l .
her lactate dehydrogenase was elevated at 2820 units / l and haptoglobin was low at less than 10 mg / dl .
coagulation profile showed international normalized ratio of 1.2 , prothrombin time of 12.6 seconds , fibrinogen 199 mg/ l and d - dimer 1.27 feu
electrolytes were within normal limits ; acute kidney injury was noted with blood urea nitrogen 51 mg/ dl and creatinine 1.9 mg / dl .
total bilirubin was markedly elevated at 32 mg% with an indirect bilirubin of 2.1 mg% .
cardiac biomarkers were elevated with creatinine kinase of 487 units / l and mb fraction of 28.8 ng / ml . troponin - t was 0.86 ng / ml . urinalysis showed ph of 6.0 , 3 + albumin , 3 + hemoglobin , eight wbcs and greater than two rbcs with some amorphous crystals .
echocardiography demonstrated an ejection fraction of 4045% with severe hypokinesis of the inferior and basal anteroseptal wall .
no significant valvular lesions were noted . in view of the acute onset of symptoms associated with microangiopathic hemolytic anemia , thrombocytopenia ,
acute kidney injury and waxing and waning mental status , the presumptive diagnosis of ttp was made .
a disintegrin and metalloproteinase with thrombospondin motifs ( adamst-13 ) activity was found to be low with presence of adamst-13 inhibitors in the plasma .
she improved clinically with this treatment and normalized her platelets and lactate dehydrogenase , and ste in her ecg resolved [ figure 2 ] .
outpatient cardiovascular follow - up demonstrated normalization of the left ventricular ejection fraction by echocardiography and a completely normal nuclear myocardial perfusion stress study .
further testing with invasive catheterization was not pursued as the entire episode was considered to be transient , secondary to metabolic derangement .
ttp is defined as a severe , thrombotic microangiopathy that is characterized primarily by systemic platelet - von willebrand factor aggregation , organ ischemia , profound thrombocytopenia and fragmentation of erythrocytes .
pathologically , focal areas of necrosis and hemorrhage may be seen in the pancreas , adrenals , heart , brain and kidneys.[35 ] although myocardial injury and necrosis are observed in a large number of patients with ttp , it is infrequently the initial presentation , and most likely thought to be due to microthrombi from massive platelet aggregation than plaque rupture  thrombosis cascade .
various studies have determined the incidence of myocardial infarction in ttp to range from 1541%.[69 ] however , the heart is one of the most frequently involved organs at autopsy examination of patients with ttp .
mortality is considerably higher in patients with ttp who have positive cardiac biomarkers , necessitating closer monitoring in this subgroup .
early recognition of myocardial injury in a case of ttp is crucial as it identifies higher risk .
however , invasive therapy in the form of cardiac catheterization and pci may be fraught with complications and is precluded by acute kidney injury and low platelet count .
thrombocytopenia also prevents the use of usual medical management in acs such as antiplatelet and anticoagulant therapy .
beta blockers and hmg coa reductase inhibitors may be used although their role is questionable . in acute bouts of ttp , such as this case , the treatment of choice is rapid initiation of plasmapheresis .
in addition , immunosuppressive therapy including steroid therapy is helpful , especially in the setting of auto - antibodies against adamst-13 factor . relapsing
cases of ttp have been treated with rituximab , a monoclonal antibody against cd20 on memory b cells with good effect .
although cardiac involvement is common in ttp , as an index event it can be misleading . as swift protocols are activated in the emergency room and catheterization laboratories to ensure quality control , it is equally important to integrate all aspects of patient 's clinical and objective data to detect unusual disease entities

Answer:
myocardial infarction with st segment elevation ( ste ) on electrocardiography ( ecg ) is a common presentation in emergency rooms across the world .
 myocardial injury and necrosis are infrequently the initial presentation in patients with thrombotic thrombocytopenic purpura ( ttp ) . a 48-year - old woman presented with ste myocardial infarction from outside hospital for primary percutaneous coronary intervention .
 however , her clinical picture was not consistent .
 rapid evaluation revealed symptoms associated with microangiopathic hemolytic anemia , thrombocytopenia , acute kidney injury with waxing and waning mental status .
 a diagnosis of ttp was made with low adamst-13 activity .
 plasmapheresis was initiated along with intravenous steroid therapy .
 the patient had a full recovery and went home after full recovery of left ventricular ejection fraction and normal myocardial perfusion studies .
 rapid evaluation is needed to identify infrequent causes of ste myocardial infarction . as swift protocols are activated in the emergency room and catheterization laboratories to ensure quality control ,
 it is equally important to integrate all aspects of the patient 's clinical and objective data to detect unusual disease entities .


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:
russell body duodenitis ( rbd ) is a rare inflammatory disease characterized by an abundance of polyclonal plasma cells present in the duodenal mucosa .
these plasma cells contain intracytoplasmic eosinophilic globules of condensed immunoglobulin , the so - called russell body .
we describe the case of a patient with rbd in whom endoscopic and histopathologic findings were observed chronologically , along with a review of the relevant literature .
he was found to have a nodule in the right middle lung field on a plain chest radiograph at a local clinic , and was referred to our hospital for detailed examination .
a nodule measuring 2 cm was detected in segment 8 of the right lung on chest plain computed tomography ( ct ) .
the morphology of the nodule was lobulated , and cavitation was observed in the interior .
results of smear , culture , and polymerase chain reaction assay from sputum specimens were all negative for tuberculosis .
bronchoscopy was performed on hospital day 9 , during which bronchial lavage fluid was collected , and a biopsy of the nodule was performed .
double capsule - like circular objects were positive for periodic acid - schiff stain and grocott stain , yielding a diagnosis of pulmonary cryptococcosis .
moreover , the level of the cluster of differentiation ( cd ) 4 was 570/l , the cd8 level was 655/l , and the cd4/cd8 ratio was 0.87 , suggesting no evidence of aids . on hospital
esophagogastroduodenoscopy ( egd ; day 14 ) revealed a significant amount of residue and an irregular ulceration with surrounding elevation of the duodenal bulb ( fig .
1a ) , which had brought about severe stenosis . with the suspicion of duodenal cancer , biopsy samples were obtained from ulcer edges .
although admixed with various inflammatory cells , necrotic tissues were observed , but no definition of adenocarcinoma cells was found ( fig .
however , since some large atypical cells were admixed with infiltrating inflammatory cells , reexamination was required to rule out undifferentiated carcinoma and malignant lymphoma .
the second egd ( day 21 ) and the third egd ( day 30 ) revealed no signs of ulcer healing .
contrast - enhanced upper gastrointestinal radiography ( day 37 ) revealed severe stenosis from the duodenal bulb to the superior duodenal angle ( fig .
2 ) . positron emission tomography - ct was performed to screen the whole body for malignant tumors .
no significant accumulation of fluorodeoxyglucose was observed in any site except the lesion of pulmonary cryptococcosis in the right lung , and no accumulation was detected in the duodenal bulb .
considering this benign stenosis , we performed a gastrojejunostomy ( day 43 ) , and thereafter , oral intake became possible .
the fourth egd ( day 56 ) revealed that the peripheral redness and edema of the ulcers had become more severe than in the previous findings ( fig .
biopsy samples revealed dissemination of large cells with eosinophilic cytoplasms and eccentric nuclei in the necrotic / granulation tissue of the duodenal lamina propria ( fig .
3b ) . the large cells were cd20( ) , cd68( ) , cd79a(+ ) , and s100( ) , and they were  chain(+ ) or  chain(+ ) , suggesting russell bodies derived from polyclonal plasma cells ( fig .
the fifth egd ( day 91 ) revealed that the ulcers in the duodenal bulb had reduced in size , and some scarring was present ( fig .
although a biopsy at this time confirmed the presence of a few russell bodies , the majority had disappeared ( fig .
the patient is being followed up while continuing the oral administration of a proton pump inhibitor ( ppi ) .
hsu et al .   showed that russell bodies originate from distended rough endoplasmic reticulum in which immunoglobulin is inhibited from being secreted and condensed .
tazawa and tsutsumi   first reported russell body gastritis ( rbg ) in 1998 , in which russell bodies were found in many plasma cells infiltrating the gastric mucosa .
first reported in a patient positive for hiv ; only five cases have since been reported [ 5 - 8 ] .
the differential diagnoses include plasmacytoma , mucosa - associated lymphoid tissue lymphoma , and signet ring cell carcinoma . in the present case , because the russell bodies were derived from plasma cells positive for cd79a and were suggested to be polyclonal by the mixture of  and  chain - positive cells , rbd was diagnosed .
many patients with rbg are positive for h. pylori , which is believed to be associated with the development of rbg .
however , only one of the five previously reported cases of rbd was positive for h. pylori .
the other background diseases were hiv infection in one , crohn disease in one , retroperitoneal metastasis of ureteral cancer in one , and adenocarcinoma of the ascending colon in one case .
although the development of russell bodies is assumed to be associated with chronic inflammation , microorganisms , and immunodeficiency , the causes of their development remain unknown .
although russell bodies are frequently found in benign tissue adjacent to a malignant tumor , there are also reports suggesting that the production of chemokines in tumor cells is associated with the development of russell bodies . in the present case ,
the patient was negative for h. pylori and hiv , and there was no evidence of malignancy or immunodeficiency .
we could chronologically observe the endoscopic appearance and histopathological findings of rbd in our patient .
when the ulcers were first detected , although severe infiltration of inflammatory cells was observed , rbd was not manifested . through the aggravation of the ulcers
furthermore , the fifth egd revealed a tendency for the ulcers to heal , and the majority of the russell bodies had disappeared . from these processes , it was assumed that the russell bodies were not a cause of the ulcerations , but byproducts secondarily induced by a severe inflammatory state after the development of the ulcers . in the present case , because food residues were always retained in the duodenal bulb , mechanical stimulation might also have been associated with the development of the russell bodies .
regarding therapeutic responses of russell bodies , there is a report of patients with rbg who were positive for h. pylori , in whom the endoscopic findings improved after h. pylori eradication and the russell bodies disappeared .
the present patient was negative for h. pylori and had not undergone h. pylori eradication .
his treatment consisted of administration of a ppi and gastrojejunostomy , which are assumed to have contributed to the resolution of the local inflammation . as for the correlation with the degrees of inflammation at the ulcer site
, the russell bodies would be expected to appear and disappear as the degree of inflammation changed .
the prognosis was favorable with the internal use of a ppi in cases of rbg negative for h. pylori .
there have been no published reports of recurrence or malignant transformation during follow - up .
however , it is often difficult to distinguish russell bodies from plasmacytoma , mucosa - associated lymphoid tissue lymphoma , and signet ring cell carcinoma .
multiple endoscopic observations and biopsies , like that used in the present case , are required to diagnose malignant disease .
this was a valuable case in which the clinical and pathological features of rbd , an extremely rare disease , could be compared in the present patient from onset to healing .

Answer:
a 64-year - old man was found to have a nodule in his right lung .
 he also complained of nausea and abdominal pain during the clinical course .
 esophagogastroduodenoscopy revealed a duodenal ulcer associated with severe stenosis and a suspicion of malignancy .
 however , three subsequent biopsies revealed no evidence of malignancy .
 the fourth biopsy showed scattered large eosinophilic cells with an eccentric nucleus , leading to a diagnosis of russell body duodenitis ( rbd ) .
 rbd is an extremely rare disease , and little is known about its etiology and clinical course .
 the pathogenesis of rbd is discussed based on our experience with this case .