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:
despite a considerable progress in malaria control in iran over the past few years that led to significant reduction of cases , the disease still remains a major health problem in south and southeastern parts of the country .
2008 , afsharpad et al . 2012 ) and insecticide resistance of anopheles vectors ( enayati et al .
2012 ) are aggravated by continuous influx of imported cases , mostly with plasmodium falciparum , from neighboring countries of afghanistan and pakistan ( zakeri et al .
the latest checklists of iranian mosquitoes include 28 anopheles species , identified mostly on the basis of morphological features , and a few by dna - based approaches ( azari - hamidian 2007 ) .
maculipennis are known to be responsible for transmission of malaria in the country ( manouchehri et al .
some important malaria vectors in iran are assumed to be members of species complexes or species groups , which are often difficult to distinguish morphologically .
application of dna - based approaches has resolved some cryptic species in iranian complex species including an .
fluviatilis , however , the identity of some members are still doubtful or were refuted later ( azari - hamidian 2007 , naddaf et al .
this , to great extent , is due to introduction of molecular markers such as its2 and 28s - d3 genes for discriminating the members of this complex species in india ( manonmani et al .
biology , variation in behaviors , and role of this species in malaria transmission in different geographical areas of iran has been extensively reviewed by others ( eshghi et al .
1976 , edalat 19971998 , hanafi - bojd et al . 2012 ) . in an early study comparison of its2 sequence of iranian specimens from various localities in south and southeastern
iran revealed only species y , which is presumably species t ( naddaf et al . 2003 ) , however , rapd - pcr analysis of same specimens revealed two distinct patterns , separating representatives of fars province from other areas ( naddaf et al .
analysis of 28s - d3 gene from same populations corroborated rapd results , fars province specimens showed to be identical to species u in india , while individuals from other areas exhibited heterozygocity at the only base pair position that identifies species u and t ( naddaf et al . 2010 ) .
in addition , in a separate study based on 28s - d3 analysis , species t and species u were reported from jiroft of fars province and chabahar of sistan va baluchestan province , respectively ( mehravaran et al . 2011 ) .
the aim of this study was to evaluate cytochrome oxidase i ( coi ) gene alongside 28s - d3 as a diagnostic tool for identification of an .
coi gene sequences have been extensively used for population studies and resolving evolutionary relationship among closely related species groups of insects ( lunt et al . 1996 ) and
anopheline mosquitoes ( krzywinski and besansky 2003 ) . variations in this fragment have been exploited as dna barcodes for identifications of culicidae mosquitoes including an .
fluviatilis mosquitoes originated from different localities in south and southeastern areas of iran including fars , hormozgan , kerman , and sistan va baluchestan provinces .
the extraction method and identity of some mosquitoes based on its2 and/or 28-d3 genes were described previously ( naddaf et al .
all the dna samples were initially subjected to allele specific ( as)-pcr based on 28s - d3 gene as described by singh et al .
the coi gene was amplified using universal primers , ubc6 ( 5- gga gga ttt gga aat tga tta gtt cc -3 ) and ubc9 ( 5-ccc ggt aaa att aaa ata taa act tc-3 ) , designed by simon et al .
each 25l reaction contained 20 pmol of each primer , 2 mm mg cl2 , 10 mm tris - hcl , 50 mm kcl , 150m of dntps , 1u of taq , and 2l of dna .
pcr products were purified using a gel band purification kit ( pharmacia , piscataway , nj , usa ) according to manufacturer s recommendations and later sequenced using the same primers as used for amplification at seqlab laboratory in germany .
the sequences were manually edited and corrected using bioedit software , version 7.1.3.0 ( hall 1999 ) and fragments of 474 bp length were selected for analysis .
the distances between groups and between individual sequences were calculated , and phylogenetic tree for iranian sequences was generated using the kimura two parameter ( k2p ) model of neighbor - joining method in a complete deletion procedure using mega 4 software ( tamura et al .
the sequence data for the coi gene sequences were submitted to genbank with the accession numbers jx020706-jx020729 .
fluviatilis mosquitoes originated from different localities in south and southeastern areas of iran including fars , hormozgan , kerman , and sistan va baluchestan provinces .
the extraction method and identity of some mosquitoes based on its2 and/or 28-d3 genes were described previously ( naddaf et al .
all the dna samples were initially subjected to allele specific ( as)-pcr based on 28s - d3 gene as described by singh et al .
the coi gene was amplified using universal primers , ubc6 ( 5- gga gga ttt gga aat tga tta gtt cc -3 ) and ubc9 ( 5-ccc ggt aaa att aaa ata taa act tc-3 ) , designed by simon et al . (
each 25l reaction contained 20 pmol of each primer , 2 mm mg cl2 , 10 mm tris - hcl , 50 mm kcl , 150m of dntps , 1u of taq , and 2l of dna .
pcr products were purified using a gel band purification kit ( pharmacia , piscataway , nj , usa ) according to manufacturer s recommendations and later sequenced using the same primers as used for amplification at seqlab laboratory in germany .
the sequences were manually edited and corrected using bioedit software , version 7.1.3.0 ( hall 1999 ) and fragments of 474 bp length were selected for analysis .
the distances between groups and between individual sequences were calculated , and phylogenetic tree for iranian sequences was generated using the kimura two parameter ( k2p ) model of neighbor - joining method in a complete deletion procedure using mega 4 software ( tamura et al .
the sequence data for the coi gene sequences were submitted to genbank with the accession numbers jx020706-jx020729 .
all the dna specimens from fars province yield only a product of approximately 375 bp length indicative of species u , whereas specimens from hormozgan , kerman and sistan va baluchestan provinces amplified two bands of 375 bp and 128 bp length .
phylogenetic analysis using coi gene grouped individuals from fars province in two distinct clades separate from other iranian individuals representing populations of hormozgan , kerman , and sistan va baluchestan ( fig .
the mean distance between iranian and indian groups was 1.66% , while the value between fars group and the group comprising other iranian members was 2.06% .
the indian group exhibited the same distance ( 2.06% ) with fars group . the highest distance ( 3.09% ) among iranian individuals was between specimens 930 from fars province and 398 from sistan va baluchestan province .
six individuals belonging to two clades ( 87 , 97 , 655 , and 928 ) and ( 92 ) from fars province showed 100% identity .
in addition , ten individuals from other geographical areas including four from koveh ( 170 , 172 , 173 , and 186 ) and one from minab ( 121 ) in hormozgan province , two from abchekan ( 392393 ) in sistan va baluchestan province , and three from kahnouj in kerman province ( 815 , 836 , and 839 ) were 100% identical .
accurate identification of malaria vectors is not only one of the most basic requisite for success of malaria control programs , but also has become an intriguing issue for understanding speciation process and evolution of anopheles mosquitoes . in absence of cytotaxonomic evidence , rapd - pcr methodology and variation in 28s - d3 gene have resolved two potential sibling species in an .
we report further evidence for the occurrence of these two sibling species by coi analysis of mitochondrial dna from the same specimens .
anopheles fluviatilis james is a complex of cryptic species ; cytotaxonomic studies of polythene chromosomes has revealed three reproductively isolated species in india known as s , t , and u ( subbarao et al . 1994 ) .
application of the first dna - based method using its2 gene identified two putative species of x and y that are presumably equivalent to species s and t , respectively ( manonmani et al .
later , a complete as - pcr assay based on variations of 28s - d3 gene against chromosomally examined specimens identified all the members of the complex ( singh et al .
fluvialitis mosquitoes of iran . however , the same specimens displayed variations in 28s - d3 gene ; the individuals from fars exhibited similarity with species u in india whereas individuals from others areas showed heterozygocity at the single nucleotide position that identifies species u and t. the identity of an .
fluviatilis complex in iran became complicated as the heterozygocity in 28-d3 was not reflected in its2 fragment and individuals from fars province exhibited dual identity of t and u based on its2 and 28s genes , respectively ( chen et al .
fluviatilis sibling species were not addressed in their study , however , k2p genetic distances between different species of culicidae were reported to be > 2% . in our study , the mean distance between iranian and indian populations was 1.66% , whereas the value between fars group and the group comprising other iranian individuals was 2.06% .
the distance between most individuals from fars province and individuals from other areas was > 2% .
two individuals ( 9192 ) from fars province exhibited almost equivalent distance with all other members including those ( 930 , 926 , 928 , 655 , 87 , and 97 ) from the same province .
jf966741 , unpublished ) that showed a high divergence from other sequences and appeared as an out group beyond an .
the results of present study were almost concordant with earlier results obtained by rapd - pcr methodology and 28s - d3 analysis ( naddaf et al .
this study shows that coi gene can be used as a useful tool along other dna markers like 28-d3 gene for dissolving closely related taxa of an .
fluviatilis mosquitoes ( by its2 and 28s - d3 genes ) from india , iran , and other geographical areas by this genetic marker can bring more insight into taxonomy of this sibling species .
this study shows that coi gene can be used as a useful tool along other dna markers like 28-d3 gene for dissolving closely related taxa of an .
fluviatilis mosquitoes ( by its2 and 28s - d3 genes ) from india , iran , and other geographical areas by this genetic marker can bring more insight into taxonomy of this sibling species .

Answer:
background : anopheles fluviatilis , one of the major malaria vectors in iran , is assumed to be a complex of sibling species .
 the aim of this study was to evaluate cytochrome oxidase i ( coi ) gene alongside 28s - d3 as a diagnostic tool for identification of an .
 fluviatilis sibling species in iran.methods:dna sample belonging to 24 an .
 fluviatilis mosquitoes from different geographical areas in south and southeastern iran were used for amplification of coi gene followed by sequencing .
 the 474475 bp coi sequences obtained in this study were aligned with 59 similar sequences of an .
 fluviatilis and a sequence of anopheles minimus , as out group , from genbank database .
 the distances between group and individual sequences were calculated and phylogenetic tree for obtained sequences was generated by using kimura two parameter ( k2p ) model of neighbor - joining method.results:phylogenetic analysis using coi gene grouped members of fars province ( central iran ) in two distinct clades separate from other iranian members representing hormozgan , kerman , and sistan va baluchestan provinces .
 the mean distance between iranian and indian individuals was 1.66% , whereas the value between fars province individuals and the group comprising individuals from other areas of iran was 2.06%.conclusion : presence of 2.06% mean distance between individuals from fars province and those from other areas of iran is indicative of at least two sibling species in an .
 fluviatilis mosquitoes of iran .
 this finding confirms earlier results based on rapd - pcr and 28s - d3 analysis .


Question:
You will be shown the title of a chemistry paper, together with sections excerpted from the body of the paper. The paper sections may include HTML tags like `<p>` and `</p>`; please ignore these. Your task is to write an abstract for the paper. Your response should include the abstract and no other text.

Title:
A three-component, Zn(OTf)2-mediated entry into trisubstituted 2-aminoimidazoles

Paper sections:

This article is part of the thematic issue "Multicomponent reactions III".

Introduction

The pioneering publications of Beller and co-workers describing Zn(OTf)2-catalyzed, microwave-promoted conversion of a mixture of a secondary propargylamide and an amine into a trisubstituted imidazole 1 [1–2] inspired us to explore several variants of this methodology. Last year, we described the synthesis of differently substituted imidazoles 2 from tertiary propargylamides and ammonium chloride under conventional heating [3]. More recently, we applied the Beller protocol to the synthesis of 2-substituted 5-methyloxazoles 3 from secondary propargylamides [4]. Being curious to explore more variants of N-carbonyl propargylamines, we turned our attention to propargylureas 4. These have been previously converted to the respective 2-imidazolones via base-promoted intramolecular amination of the propargyl group [5–6]. However, such transformations have not been studied under transition metal or Lewis acid catalysis. Moreover, the possibility to incorporate of an external primary amine into the cyclization process, which would lead to trisubstituted 2-aminoimidazoles 5 has not been explored (Figure 1). 2-Aminoimidazoles have a remarkably broad utility in medicinal chemistry [7]. Moreover, ureas 4 can, in principle, be generated in situ from the respective isocyanates and propargylamine (or propagyl isocyanate and primary amines), thus could offer an opportunity to synthesize 2-aminoimidazoles 5 in a three-component format. Considering these premises, we started to explore the Zn(OTf)2-catalyzed reaction of 4 with primary amines. Herein, we present the preliminary results of these studies.

Examples of imidazole (1 and 2) and oxazole (3) syntheses from propargylamides previously reported and the reaction of propargylureas 4 with primary amines studied in this work.

Results and Discussion

Urea 4a (prepared by reacting propargylamine with 4-(trifluoromethoxy)benzyl isocyanate) was reacted with an equivalent amount of benzylamine in refluxing toluene in the presence of various Lewis acids. To our delight, the desired product 5a was observed and isolated in all cases involving Zn(OTf)2 catalysis. However, in contrast to previous reports on the preparation of related compounds [1–4], the reaction required substantial amounts (optimally, 50 mol %) of Zn(OTf)2 to achieve the best yield (76%). Notably, neither Sc(OTf)2 nor Cu(OTf)2 employed as catalysts produced a trace of the desired product. To rule out catalysis by adventitious TfOH, the reaction was performed in the presence of an equimolar amount of triflic acid, but no conversion could be detected (Table 1).

Catalyst screening results for the conversion of 4a to 5a.

Results and Discussion

Considering that in situ preparation of ureas 4 could, in principle, enable a three-component entry to imidazoles 5 (an attractive option from the standpoint of library array synthesis), we compared the isolated yield of the above reaction (with the ready-made urea 4a) with the yield obtained in the three-component format. To our delight, the three-component format led to only a slightly lower yield of 5a (62%). Viewing this as a worthy toll for the convenience of multicomponent chemistry, we proceeded investigating the scope of the newly established synthesis of trisubstituted 2-aminoimidazoles 5 (Figure 2).

Substrate scope for the three-component synthesis of 5.

Results and Discussion

As it is evident from the data presented in Figure 2, the newly developed approach to the synthesis of medicinally important 2-imidazolines allows for independent variation of two periphery elements and provides generally good yields of the target compounds. The reaction can be performed with both, aromatic and aliphatic isocyanates. However, its scope is limited to aliphatic amines as the reaction failed to work for anilines (even electron-rich ones, such as p-anisidine). The tolerance of acid-labile protecting groups such as Boc is particularly useful as it offers an opportunity for further side-chain modifications.

From the mechanistic prospective, the reaction probably proceeds via Zn(OTf)2-catalyzed alkyne hydroamination followed by cyclodehydration as depicted in Figure 3, in full analogy with the previously proposed mechanism [2–3].

Plausible mechanism for the formation of 5.

Conclusion

In summary, we have successfully employed propargylureas in the synthesis of trisubstituted 2-aminoimidazoles. This is the first example illustrating the utility of such ureas in the synthesis of imidazoles as previously reported syntheses only involved base-promoted cyclization into 2-imidazolones. The reaction can be conveniently conducted in a three-component format which makes it a useful tool for library array synthesis. The investigation of other metal-catalyzed transformations of propargylureas is underway in our laboratories and will be reported in due course.

General experimental information, synthetic procedures, analytical data and NMR spectra for the reported compounds.

Answer: A three-component reaction involving in situ generation of propargylureas and subsequent Zn(OTf)2-mediated cyclocondensation with a primary amine yielded trisubstituted 2-aminoimidazoles. These findings are in contrast to the previously reported base-promoted unimolecular cyclization of propargylureas (leading to 2-imidazolones) and extend the range of Lewis acid-catalyzed azole syntheses based on N-carbonyl propargylamines.


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:
benign neoplasms of the salivary glands are frequently encountered in dental practice . these account for 3% of the tumors involving the head and neck .
the majority of them occur in the parotid gland , and 80% of them are benign . of these benign neoplasms ,
50 - 80% are pleomorphic adenomas and 5 - 20% are warthin 's tumors ( wt ) .
however , warthin 's tumor is the most frequent monomorphic adenoma of the major salivary glands .
this is a curious benign neoplasm with its intimidating histological name , papillary cyst adenoma lymphomatosum .
however , the eponym wt has been extensively used ever since aldred warthin reported two cases of this tumor in 1929 .
earlier in the literature this was also referred to as adeno - lymphoma , papillary cyst adenoma , cystadeno - lymphoma , and epitheliolymphoid cyst .
wt is generally a disease of elderly men , with the highest incidence in the sixth and seventh decades and the male : female ratio is 4.6:1 .
the typical features on cytology of wt include oncocytic cells in cohesive , monolayered sheets ; background lymphocytes ; and amorphous , cystic debris .
histopathologically , it has a cystic appearance with a double layer of oncocytes surrounding a lymphoid stroma .
the following case presentation deals with wt of the left parotid gland and highlights its clinicopathologic concepts along with its therapeutic management .
a 65-year - old male patient visited the department of oral medicine , with the chief complaint of swelling below the left ear lobe since six years .
patient was a known smoker since the past 25 years and there was no history of alcohol consumption . on examination , the lesion extended from the left ear lobule to the lower border of the ramus of the mandible superoinferiorly and also extended behind the left ear [ figure 1 ] .
it was approximately 5 cm in greatest dimensions ; smooth contoured , was firm in consistency and had well - defined borders .
stimulation of the parotid glands yielded normal salivary flow with normal consistency , quantity and color .
based on the history and clinical examination , a provisional diagnosis of warthin 's tumor was given .
a differential diagnosis of pleomorphic adenoma , a low - grade parotid malignancy , lipoma and neurofibroma arising in the salivary gland were included .
the investigatory workup included complete hemogram , extra - oral radiograph , ultrasonography , computed tomography and excisional biopsy of the lesion .
ultrasonographic finding showed a well - defined hypoechoic mass in the lower pole of the left parotid gland .
the rest of the parotid gland parenchyma was normal and there was no evidence of ductal dilatation . computed tomography examination revealed a rounded and well - defined cystic lesion involving the superficial lobe of the left parotid gland [ figure 3 ] .
ultrasonograph showing well - defined hypoechoic mass computed tomography examination showing the lesion later , excisional biopsy of the lesion was planned using partial parotidectomy as the technique of choice [ figure 4 ] .
the tissue obtained was fixed in 10% of neutral buffered formalin , and processed routinely .
the sections stained with hematoxylin and eosin revealed cystic spaces lined by a papillary epithelial proliferation which was bilayered .
the cells of the epithelial lining appeared intensely eosinophilic . at the core of papillary projections
a variable amount of lymphoid tissue with mature lymphocytes was observed [ figure 5 ] .
tumor after superficial parotidectomy microscopic picture ( 10 ) the patient did not present with any post - surgical complications .
the most accepted hypothesis about the origin of wt is that it develops from salivary duct inclusions in the lymph nodes , after the embryonic development of the parotid gland .
this hypothesis is further supported by the frequent detection of salivary gland tissue in the peri- and intraparotidal lymph nodes . in the parotid region , lymph nodes
the tumors presenting epithelial differentiations similar to those observed in wt develop outside lymph nodes and have no lymphoid stromal component .
benign tumors have only rarely been associated with cigarette smoking , which focuses attention on the nature of the underlying neoplastic process and how it may differ from other benign tumors .
although generally believed to be an adenoma , wt , as suggested by allegra , may be a delayed hypersensitivity reaction .
an interesting fact that caught the attention of the pathologists is that a decline in the incidence in men and a concurrent increased incidence in women has been observed in recent years .
the change is probably due to decline in the smoking habit in men and a reverse trend in women .
the increased frequency of adenolymphoma has been ascribed to the association of adenolymphoma with smoking and the proportional increase in female smokers .
studies conducted among atomic bomb survivors suggest that radiation may also be implicated in the tumorigenesis
barr virus ( ebv ) , because of the ebv  dna found in tumor cells in some studies has not been substantiated .
clinically , wt occurs almost exclusively in the parotid glands , in its superficial lobe and rarely in the deeper lobe ( 10% ) .
the other preferred locations include the buccal mucosa , submaxillary gland , lip and palate .
the patients can be asymptomatic or can have facial pain , rarely , facial nerve palsy may be seen in tumors associated with inflammation and fibrosis , which can be mistaken for malignant tumor .
ipsilateral earache , tinnitus and deafness are uncommon ear symptoms that might be seen in some patients .
the size is variable , from a few millimeters to centimeters , averaging 2 to 4 cm in diameter , with a preferred location in the lower pole of the gland ( in the jaw angle ) .
it has been reported predominantly in whites , less frequently in orientals , and rarely in blacks .
the incidence rate is higher than that of salivary gland cancer but is lower than that of benign mixed tumors ( pleomorphic adenoma ) .
macroscopically wt presents as a spherical or ovoid mass , with a dense fibrous capsule and displaying multiple cystic compartments filled with a viscous yellow or dull brown material . however , eveson and cawson found 77% cases with an incomplete capsule , a full capsule in 8% and 16% tumors in which there was no evidence of capsule .
the cytological smears in our case showed variable amounts of cellularity , ranging from barely optimum cellularity to occasional hypercellularity .
there was an admixture of epithelial fragments , occasional single epithelial cells , and abundant lymphocytes noted in a granular cystic background .
the epithelial cells were oncocytic in appearance with large nuclei , prominent nucleoli , and moderately abundant granular cytoplasm .
since wt can be multifocal , a preoperative diagnosis by means of fine needle aspiration biopsy is mandatory and complete bilateral screening of the gland by mri is needed to program surgery .
. an experienced cytopathologist can reliably distinguish malignant salivary pathologies from benign , but a histological classification based on only aspiration is an unrealistic goal .
computerized tomography and magnetic resonance imaging enable accurate assessment of tumor extension , compression or infiltration of adjacent structures , presence of nodal metastases and better planning of the therapeutic approach .
dynamic dual - phase scinti - scanning with technetium-99 , a recognized method of identifying adenolymphoma , could be used more frequently in these selected patient groups .
lesion vascularity on initial power doppler examination is often relatively sparse , but wt that did contain areas of vascularity on initial examination showed a reduction in this vascularity as the tumor size reduced . with regard to luminal cells of the tumor lining the lymphoid stroma the cells reveal a similar aspect to the striated ducts of the normal salivary glands and have numerous mitochondria . these cells , called oxifile or oncocytic cells are swollen epithelial cells , with abundant eosinophilic granular cytoplasm , rich in mitochondria and enzymes .
an increased number of oncocytic cells are also observed in the normal salivary glands once the person gets older .
the diffuse proliferation of the oncocytes without other changes has no pathologic significance and is called oncocytosis or oncocytic metaplasia .
the epithelial cells , the oncocytes , are disposed on two layers , a luminal layer of oncocytic columnar cells , supported by a discontinuous layer of oncocytic basal cells .
the nuclei of the luminal cells appear uniform and display palisading towards the free surface .
the basal cells possess round to oval nuclei , centrally located , small , with conspicuous nucleoli .
the lumen of the cysts contains thick proteinaceous secretions , cellular debris , cholesterol crystals , and sometimes , laminated bodies that resemble corpora amylacea .
seifert recognizes four subtypes : subtype 1 ( classic wt ) is 50% epithelial ( 77% of all wt ) ; subtype 2 ( stroma - poor ) is 70 - 80% epithelial ( 14% cases ) ; subtype 3 ( stroma - rich ) is only 20 - 30% epithelial ( 2% ) ; and subtype 4 is characterized by extensive squamous metaplasia .
however , presence of cellular atypia and a pseudoinfiltrative appearance of the metaplastic squamous epithelium in the residual tumor often can be mistaken for squamous cell or mucoepidermoid carcinoma .
squamous metaplasia of wt usually lacks keratinization , which is seen in most squamous cell carcinoma .
in contrast to low - grade mucoepidermoid carcinoma , there is no definite infiltrative growth and the tumor cells appear more frankly squamous .
a differential diagnosis must be made also with a variant of papillary thyroid carcinoma recently reported as  warthin - like  .
the microscopic characteristic is a prominent lymphoid stroma and oncocytic metaplasia of the epithelium , but the nuclei have chromatin clearing , inclusion and groove - formation and the epithelial cells show immunohistochemical expression of thyroglobulin .
the differential diagnosis of this malignancy should be performed preferably with pleomorphic adenoma and cystoadenoma .
the anatomico - pathological diagnosis is generally easy , but it also should be distinguished from canalicular adenoma , sialadenoma as well as from branchial cyst when involving the parotid gland .
sunardhi - widyaputra and van darmne in 1993 immunohistochemically studied the presence of tenacin , a molecule in the mesenchyme of salivary glands believed to play a role in the embryogenesis and development of tumors , in papillary cystadenoma lymphomatosum and in oncocytoma .
they found the protein to be abundant in papillary cystadenoma lymphomatosum , prominent in the proximity of the basement membrane , beneath the oncocytic epithelial components .
tenacin staining in oncocytoma was focal although oncocytes are the actively proliferating cells in this tumor .
the presence of oncocytic myoepithelial cells both in papillary cystadenoma lymphomatosum and in oncocytoma surrounded by tenacin suggested that both tumors may arise from stem cells that are capable of differentiating into aberrant epithelial cells ( oncocytes ) , myoepithelial cells in variable proportion or both .
recent molecular studies have shown that the epithelial component is polyclonal and does not exhibit clonal allelic losses , suggesting that this tumor is not a true neoplasm .
recent studies have also reported the presence of b - cells ( cd20 ) , nk ( cd56 ) and t ( cd3 ) , including helper subtypes ( cd4 ) and suppressor ( cd8 ) in the tumor 's stroma , something similar to that of normal or reactive lymph nodes . also , it was found that cd20-positive b - lymphocytes were located in the germ centers and peripheral b - area while cd3-positive t - lymphocytes are located interfollicularly .
surgeons are traditionalists , and the early experience of our peers has colored current surgical opinion and slowed the introduction of conservative surgery for the benign parotid lump .
this situation is now changing , and centers with experience of treating parotid tumors increasingly recognize that benign tumors can be removed safely by techniques much less invasive than a formal parotidectomy .
this surgical modality is based on meticulous dissection immediately outside the tumor capsule with preservation of the facial nerves .
in view of the possible association of wt with extra - salivary neoplasms , extensive workup of the patients harboring multiple wt is , therefore , indicated and long - term follow - up is mandatory , due to the possible occurrence of metachronous salivary and extra - salivary tumors even after prolonged time intervals .
rarely , either the epithelial or lymphoid component of wt can undergo malignant transformation with an estimated incidence of less than 0.1% . in order of frequency ,
the commonest carcinomas are squamous cell carcinoma , oncocytic carcinoma , adenocarcinoma , undifferentiated carcinoma , mucoepidermoid carcinoma and merkel cell carcinoma .
complications must be unusual and of low frequency for the surgical resection of a wt , including some complications considered of minor importance , such as paresis of the ear lobe resulting from manipulation and/or section of the auricularis magnus branch of the superficial cervical plexus .
the auricularis magnus nerve , in its path toward the ear lobe , may pass through the tumor , hampering the dissection .
another complication of lesser importance is the change of facial contour due to resection of a large portion of the parotid gland .

Answer:
warthin 's tumor undoubtedly is the most frequent monomorphic adenoma of the major salivary glands .
 clinically , it appears as a slow - growing tumor often fluctuant on palpation due to its cystic nature .
 the treatment of choice is complete excision with wide tumor - free margins .
 this article highlights a case of warthin 's tumor of the parotid gland in an elderly male patient along with a review of the literature on the aforementioned pathology .


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:
thyroid cancer is the most common type of cancer in korea , with differentiated thyroid cancer ( dtc , includes papillary and follicular thyroid cancer ) accounting for the vast majority of cases .
the standard treatment for dtc is thyroidectomy followed by i ( radioactive iodine , rai ) therapy and thyroxine suppression to decrease serum thyroid stimulating hormone ( tsh ) .
rai therapy eliminates microscopic residual tissues after thyroidectomy which decreases the likelihood of thyroid cancer recurrence .
prior to rai therapy , the patient is advised to maintain a low - iodine diet ( lid ) to facilitate i uptake , maximizing the efficiency of rai therapy .
appropriate levels of dietary iodine intake or duration of the lid are not yet standardized over regions or countries .
the american thyroid association recommends the lid with less than 50 g / day of dietary iodine for 1 - 2 weeks prior to rai therapy , but the korean thyroid association recommends a low - iodine diet with less than 100 g / day and provide a dietary guideline for the lid where allowed or restricted food items are listed during the lid . in iodine - rich areas such as korea , the recommended level of iodine intake during the lid is important to facilitate maintaining the lid , because a strict guideline may negatively impact the lid compliance .
a few studies were reported results of less strict diet   or short periods of the lid , however , the general consensus among clinical dietitians in korea regarding appropriate degree or duration of the lid have not yet elucidated . according to moon
et al . , clinical dietitians should develop a practical dietary strategy in order to improve and facilitate the lid compliance . to improve the compliance of the lid
most previous studies used urinary iodine measurements due to the lack of an iodine database and the difficulties in dietary survey .
urinary iodine excretion is a good measure for dietary iodine intake , but evaluating the dietary iodine intake using multiple days of dietary records would provide a more comprehensive measure of dietary iodine intake in order to develop a practical dietary strategy for the lid . therefore , this study aims to assess dietary iodine level using three - day of dietary records and to search food sources that cause low adherence to the lid .
in addition , we attempted to evaluate the ablation rate of remnant thyroid by compliance of the lid .
we experienced three patients showing the diet composing iodine levels over 100 g / day despite their efforts for the lid before initial rai therapy .
the protocol of case report was approved by the institutional review board of college of medicine at seoul national university ( h-1308 - 066 - 513 ) , and all the patients provided their written informed consent to participate .
the patients had stage ii or iii papillary thyroid cancer , classified based on the cancer staging manual in the 7 edition of the american joint committee on cancer ( ajcc ) .
all three patients were educated on the preparation and management of the lid prior to rai therapy in a two - and - a - half - hour intensive education session . during the session ,
a clinical dietitian explained patients of the importance and methodology of maintaining the lid in a half - hour .
then the patients maintained the lid for two weeks prior to i administration ( 1.1 gbq ) and a whole body scan ( wbs ) , which was done three days after the i administration . to elevate their tsh levels , recombinant human tsh ( rhtsh ; thyrogen , genzyme , cambridge , ma , usa )
dietary intakes for patients were assessed using three - day dietary records during usual diet period and the lid period respectively .
patients were taught how to record their diet and asked to record three - day dietary records at two weekdays and one weekend day .
energy and nutrient intakes , except for iodine , were calculated using a diet evaluation system ( des ) .
iodine intake was estimated using the database recently established by han et al .   and modified for this study .
successful remnant ablation is defined as an absence of visible rai uptake on a subsequent diagnostic rai scan or an undetectable stimulated serum thyroglobulin ( off - tg ) level .
figure 1 presents the dietary iodine intake in both the usual diet and lid periods .
although the patients tried to maintain their lid according to the guideline of less than 100 g / day their mean daily iodine intakes during two - week lid period were more than 100 g .
for patient 1 , the mean iodine intake level for usual diet and the lid were 317.2 and 117.0 g / day respectively .
patient 2 's levels were 125.2 and 110.9 g / day and patient 3 's levels were 217.7 and 100.4 g / day .
the values in all three patients were reduced after a two - week lid period , but the iodine / creatinine ratio in spot urine exceeded 66.2 g / g ( iodide / creatinine ) , that was the cutoff value for a poorly maintained lid set by kim et al . .
all three patients followed five items out of nine food items in the lid guidelines that were using refined salts instead of sea salts and avoiding seaweeds , egg yolk , processed food , and consumed adequate amount of meat and its product , which was less than 120 g / day .
patient 1 and patient 3 also followed three more items that were avoiding fish , milk and dairy products consumption , soybean pastes and soy sauce made with sea salts .
patient 2 , however , did not follow three items and consumed fish , milk and dairy products , condiments including sea salts .
the food item in the guideline that all three patients did not follow was avoiding salted vegetables , mainly kimchi during the lid .
patient 2 showed the lowest adherence to the lid and the mean iodine intake level during the lid periods was not much different from patient 2 's usual intake level .
though serum off - tg levels became undetectable ( < 1.0 ng / ml ) for patients 1 and 2 , patient 3 's off - tg level was 1.07 ng / ml and all three patients showed visible rai uptake .
we evaluated dietary iodine during lid and successful ablation of the rai therapy for three differentiated thyroid cancer patients .
all three patients showed low adherence to the lid guideline , in particular for salted vegetable and exhibited remnant thyroid activity in the second post - rai therapy scan .
dietary assessment of iodine intake is challenging because the large day - to - day variation makes it difficult to quantify the " usual " iodine intake .
however , the dietary iodine intakes are comparable with the previous findings where dietary iodine intake was reported 478 g / day for korean healthy adults using food frequency questionnaire   and 312 g / day in men and 413 g / day in women for japanese using 7-day dietary records . in besides
, we measured urinary iodide excretion in both usual diet and the lid periods along with dietary iodine and both two values showed the same trend of being markedly reduced . although our patients were intensively educated on maintaining the lid , all of their dietary iodine intake levels exceeded the less than 100 g guideline set by the kta .
patient 2 did not follow the lid guidelines such as avoiding dairy , fish and kimchi .
patients 1 and 3 followed kta guidelines except for the restriction on kimchi . maintaining the lid is challenging for korean patients , whose regular diet consists of foods with very high iodine content , such as seaweeds , seafoods , soy sauce , soy bean pastes , and salted vegetables such as kimchi . according to moon et al . , thyroid cancer patients had considerable knowledge of high iodine content foods but they had a difficulty to prepare low iodine dishes not using sea salts . though seaweed has the highest iodine content and is by far the biggest contributor to dietary iodine consumption , the patients ' main source of iodine was kimchi during the lid period .
kimchi is a main side dish in our korean diet and is usually made of large amounts of sea salts , garlic , red pepper , salted fish and other spices . according to analytical values determined by the korean food and drug administration ( kfda ) , the iodine content per 100 g of radish kimchi , napa cabbage kimchi , and young radish kimchi are 198.4 , 143.4 , and 107.4 g   respectively .
therefore , avoiding foods with a high sea salts content , such as kimchi , is very important for successful rai therapy .
although clinical dietitian put enough emphasis on avoiding sea salts or replacing sea salts with refined salts , it is very challenging for patients to distinguish the dishes made by refined salts from all dishes or to prepare their own dishes with refined salts in daily life . to increase the adherence of the lid , more practical dietary strategy for avoiding sea salts or for replacing sea salts in our korean dishes
low adherence to the lid guideline with more than 100 g / d of dietary iodine intake level negatively influenced the efficacy of rai therapy .
future studies are required to explore the influence of various dietary iodine intake levels on the efficacy of rai therapy and to develop more practical guidelines to facilitate the lid maintenance .

Answer:
to improve the efficacy of radioactive iodine ( rai ) therapy for differentiated thyroid cancer patients , a low - iodine diet ( lid ) prior to the therapy is recommended . in iodine - rich areas such as korea , however , a strict lid is very difficult to maintain .
 we experienced the cases of three patients showing low adherence to the lid before initial rai therapy , and analyzed the main food source supplying iodine during the lid , and examined the influence of the poorly maintained lid on the efficacy of rai therapy .
 the dietary intake during the lid periods were assessed using three - day dietary records and remnant thyroid activity after the second rai administration was also evaluated .
 all patients ' mean daily iodine intake during two - week lid periods exceeded the 100 g guideline set by the korean thyroid association ( median 110.9 g , ranges 100.4 - 117.0 g ) .
 although the typical food sources of iodine intake are seaweeds in korea , salted vegetables were the main contributor to the patients ' iodine intake during the lid periods .
 remnant thyroid activity was shown on a follow - up scan in all of 3 patients suggesting low efficacy of rai therapy . in summary ,
 the patients with low adherence to the lid guideline showed unsuccessful remnant ablation , and the main food source of iodine was salted vegetables .
 further studies are necessary to examine the relationship between adherence of the lid and rai efficacy according to dietary iodine intake levels , as well as food sources that cause low adherence to the lid .
 these data can then be used to develop more practical lid guidelines .


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:
a lymphoepithelioma - like carcinoma ( lelc ) is a tumor which mimics lymphoepithelioma in terms of its pathological features .
the primary lesion of lelc occurs in the stomach , lungs , thymus , salivary glands or urinary bladder .
lelc of the urinary bladder ( lelcb ) is a rare variant of infiltrating urothelial carcinoma and was first described by zukerberg et al . in 1991 .
including this case , there are merely 105 cases in the english language medical literature , with only 8 cases reported as originating from asian countries [ 3 , 4 , 5 , 6 ] . in 1994 , amin et al .
pure ( 100% ) , predominant ( 5099% ) and focal ( < 50% )  , with the three types determining a patient 's prognosis .
we herein report a case of lelcb , with a preoperative diagnosis of an undifferentiated carcinoma , in which radical cystectomy and systemic chemotherapy were successfully undertaken .
based on previous case reports of lelcb in the english language medical literature , we examined the prognosis for lelcb .
in addition , we analyzed the preoperative diagnostic characteristics of this lelcb by measuring its apparent diffusion coefficient ( adc ) value by magnetic resonance imaging ( mri ) and compared this to those of past cases of urothelial carcinoma of the urinary bladder at our institution .
on cystoscopy , two bladder tumors were observed , one on the left side of the trigone and the other on the right side of the trigone .
a total body computed tomography ( ct ) scan was performed and the presence of distant metastases or lymph node involvement was excluded .
mri revealed that the tumor on the left side of the trigone had invaded the perivesical soft tissue of the bladder , but not the prostate or seminal vesicles ( fig .
pathological findings revealed undifferentiated atypical epithelial cells with enlarged nuclei that had formed into sheets to invade the muscle layer .
pathological findings revealed large , undifferentiated carcinoma cells with pleomorphic nuclei and prominent nucleoli , the infiltration of inflammatory cells consisting predominantly of lymphocytes , and the reach of their invasion to the perivesical soft tissue of the bladder ( fig .
the final pathological diagnosis was an invasive urothelial carcinoma , lymphoepithelioma - like variant , pt3 .
tumor cells were positive for cytokeratin ( ae1/ae3 ) ( fig . 2c ) and e - cadherin ( fig .
, cisplatin - based systemic chemotherapy was performed , and cancer recurrence was not apparent at the usual follow - up as determined by ct scan and cytological analysis .
according to the who classification criteria , lelcb is defined as a subtype of undifferentiated carcinomas .
to date 105 cases , including this one , have been described in the english language medical literature .
lelcb shows carcinomatous components contrasting with lymphocyte infiltration and mimics chronic inflammation or malignant lymphoma ; immunohistochemical stains such as for cytokeratin are helpful in distinguishing between these diseases [ 6 , 7 ] . between 1991 and june 2015 , 84 cases of lelcb , according to the classification of amin et al .
we allocated the 84 cases to two groups  pure / predominant and focal  and investigated their prognoses based on previous reports .
seventy patients ( 83% ) formed the pure / predominant group and 14 patients ( 17% ) formed the focal group .
kaplan - meier curves of overall survival rates of the pure / predominant and focal groups are shown in figure 3 . as a result ,
the pure / predominant group had as significantly better prognosis than the focal type group ( log - rank test , p < 0.001 ) ( fig .
the predominant or focal types of lelcb include squamous cell carcinoma , adenocarcinoma and urothelial carcinoma .
containing only lelc , this case seemed to have the characteristics of a pure type of lelcb .
unfortunately , there is at present no established treatment for lelcb because of its rarity as a bladder tumor subtype , with few reports existing for this disease .
some reports describe lelcb as being sensitive to cisplatin , while others suggest that it is possible to preserve the bladder in the case of a pure or predominant type , even if the tumor has invaded the muscle [ 4 , 8 , 9 , 10 ] .
adjuvant cisplatin - based chemotherapy was also instituted because radical cystectomy yielded a diagnosis of lelcb pt3 .
the combination of external beam radiotherapy and chemotherapy to preserve the bladder may be considered a suitable treatment option if the diagnosis prior to radical cystectomy is accurate .
epstein - barr virus ( ebv ) is associated with lymphoepithelioma or lelc of several tissues ( lung , stomach and salivary glands ) , except the bladder .
a close reading of the literature suggests that if tumor cells are positive for ebv rna , the tumor might be a metastasis from another tissue .
therefore , we performed ebv - encoded small rna in situ hybridization ( eber - ish ) , but this did not reveal a relationship between ebv and lelcb in this case ( fig .
however , in treating lelcb , eber - ish is useful and necessary to rule out the tumor as being a metastasis from another tissue .
mri is widely used in local staging or to detect lymph node metastases , and is essential for determining suitable treatments for bladder tumors . recently ,
measuring adc values has been suggested to be helpful in diagnosing bladder tumors . to further improve preoperative diagnostic accuracy , we retrospectively measured the adc value of this case .
the mean value was found to be 782  10 mm / s ( fig .
1c ) , which was relatively lower than the mean values we found for muscle - invading urothelial carcinomas studied at our institution ( 56 cases , median 1,047  10 mm / s ; see online suppl .
material , www.karger.com/doi/10.1159/000445049 ) . in urothelial carcinoma , in 2014 yamada et al .   reported a correlation between high adc values and good histopathological features of bladder tumors which is the case for urothelial carcinoma .
however , in spite of the relatively low adc value , the prognosis of this case was relatively good as previously described
. the low adc value calculated in this case may be due to the fact that the observed lymphocyte infiltration probably caused an increase in cell density and a decrease in diffusion capacity .
there are several pitfalls and limitations in detecting pathological characteristics of tumors , and further consideration will have to be given to the usefulness of measuring adc values of bladder tumors .
regardless , though lelcb is a rare tumor , measuring adc values may be useful in predicting the histopathological characteristics of such bladder tumors .
we treated a rare case of lelcb , classed as a pure type and with a better prognosis than the focal type according to the classification of amin et al . .
it is necessary to consider a diagnosis of lelcb when turbt indicates an undifferentiated carcinoma .
additionally , measuring the adc value of a urinary bladder tumor may be helpful in predicting its pathological features .
written informed consent was obtained from the patient for publication of this case report and accompanying images .
a copy of the written consent is available for review from the editor - in - chief of this journal .
the authors received no financial support for the research , authorship and/or publication of this paper .

Answer:
lymphoepithelioma - like carcinoma of the urinary bladder ( lelcb ) is a rare variant of infiltrating urothelial carcinoma .
 we report a case of lelcb in a 43-year - old man .
 ultrasonography and cystoscopy revealed two bladder tumors , one on the left side of the trigone and the other on the right side of the trigone .
 transurethral resection of the bladder tumors was performed and pathological analysis revealed undifferentiated carcinoma .
 we therefore performed radical cystectomy and urinary diversion .
 immunohistochemically the tumor cells were positive for cytokeratin , but negative for epstein - barr virus - encoded small rna in situ hybridization as found for previous cases of lelcb .
 the final pathological diagnosis was a lymphoepithelioma - like variant of urothelial carcinoma with perivesical soft tissue invasion .
 for adjuvant systemic chemotherapy , three courses of cisplatin were administered .
 the patient subsequently became free of cancer 72 months postoperatively .
 based on the literature , pure or predominant lelcb types show favorable prognoses due to their sensitivity to chemotherapy or radiotherapy .
 an analysis of the apparent diffusion coefficient ( adc ) values of bladder tumors examined in our institution revealed that the adc value measured for this lelcb was relatively low compared to conventional urothelial carcinomas .
 this suggests that measuring the adc value of a lymphoepithelioma - like carcinoma prior to operation may be helpful in predicting lelcb .


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:
electroconvulsive therapy ( ect ) is a strong option for treating patients with medication - resistant depression , a high risk of suicide , psychotic agitation , and other severe mental issues .
however , gaines and rees1 suggested that ect increases cerebral blood flow 1.5-fold to sevenfold and raises intracranial pressure .
these effects may increase the risk of intracranial hemorrhage , especially in patients with a brain tumor , an intracranial vascular abnormality , or hemorrhagic disease .
hemophilia , a hemorrhagic disease , is usually an x - linked recessive disorder induced by a deficiency of factor viii ( hemophilia a ) or factor ix ( hemophilia b ) .
hemophilia a is the usual form of the disorder , and occurs in about one out of every 5,00010,000 male births .
the number of patients with hemophilia b is about one - fifth that of hemophilia a. globally , the number of patients with hemophilia is estimated at about 400,000 .
although the incidence of hemophilia is low , it is possible that schizophrenia requiring ect could co - occur with hemophilia .
however , only one paper reports a demonstration of the safe usage of ect in a patient with hemophilia.2 herein , we describe a second case of successful ect for medication - resistant schizophrenia in a patient with severe hemophilia a. a 26-year - old japanese man had been treated for severe hemophilia a ( severe , coagulation factor viii activity < 1 % ; moderate , 1%5% ; mild , 5%40% ) . he was admitted to a mental hospital for auditory hallucinations , a persecution complex , world destruction fantasies , and psychomotor excitation , and was diagnosed with schizophrenia by diagnostic and statistical manual of mental disorders , fourth edition , text revision criteria .
. then haloperidol ( 12 mg / day ) was combined with olanzapine instead of risperidone .
this antipsychotic combination therapy ( olanzapine 20 mg / day plus haloperidol 12 mg / day ) was partly effective against the auditory hallucinations , but the patient s psychiatric state immediately deteriorated thereafter and suicidal ideation emerged .
in addition , his bleeding tendency worsened and multiple subcutaneous hematomas appeared on his body . because clozapine had not been approved in our province at that time and ect has immediate and strong effects on schizophrenic symptoms including suicidal ideation,3 the patient
was transferred to our general hospital for the management of hemophilia a and for ect . after consulting with hematologists ,
ect was performed after the patient had been supplemented with coagulation factor viii to prevent intracranial and systematic hemorrhage .
we administered factor viii concentrates ( 1,000 iu ; kogenate fs , bayer healthcare pharmaceuticals inc . ,
the dose of kogenate fs was determined to keep factor viii activity at 30%40% during ect .
the factor viii activity target range was recommended by hematologists based on the report by glaub et al.2 since the patient s mental state was impaired , written informed consent for the procedure was obtained from the patient s family .
bitemporal ect was administered two or three times a week . a thymatron stimulation device ( somatics ,
lake bluff , il , usa ) was used for ect ; the stimulation conditions were 0.5 ms pulses , 40 hz , 0.9 a , and 252 mc .
after a course of eight ect sessions , his world destruction fantasies , psychomotor excitation , and suicidal ideation were improved . however , since his auditory hallucinations and persecution complex persisted , a second course of eight treatment sessions was administered , which ameliorated the remaining psychiatric symptoms .
after the 16th ect session , brain mri was performed to determine whether organic brain disease was present , and there was no sign of brain disease or bleeding .
a 26-year - old japanese man had been treated for severe hemophilia a ( severe , coagulation factor viii activity < 1 % ; moderate , 1%5% ; mild , 5%40% ) .
he was admitted to a mental hospital for auditory hallucinations , a persecution complex , world destruction fantasies , and psychomotor excitation , and was diagnosed with schizophrenia by diagnostic and statistical manual of mental disorders , fourth edition , text revision criteria .
however , the auditory hallucinations , persecution complex , and psychomotor excitation persisted . then haloperidol ( 12 mg / day )
was combined with olanzapine instead of risperidone . this antipsychotic combination therapy ( olanzapine 20 mg / day plus haloperidol 12 mg / day )
was partly effective against the auditory hallucinations , but the patient s psychiatric state immediately deteriorated thereafter and suicidal ideation emerged .
in addition , his bleeding tendency worsened and multiple subcutaneous hematomas appeared on his body . because clozapine had not been approved in our province at that time and ect has immediate and strong effects on schizophrenic symptoms including suicidal ideation,3 the patient
was transferred to our general hospital for the management of hemophilia a and for ect . after consulting with hematologists ,
ect was performed after the patient had been supplemented with coagulation factor viii to prevent intracranial and systematic hemorrhage .
we administered factor viii concentrates ( 1,000 iu ; kogenate fs , bayer healthcare pharmaceuticals inc . ,
the dose of kogenate fs was determined to keep factor viii activity at 30%40% during ect .
the factor viii activity target range was recommended by hematologists based on the report by glaub et al.2 since the patient s mental state was impaired , written informed consent for the procedure was obtained from the patient s family .
bitemporal ect was administered two or three times a week . a thymatron stimulation device ( somatics , lake bluff , il , usa ) was used for ect ;
the stimulation conditions were 0.5 ms pulses , 40 hz , 0.9 a , and 252 mc .
after a course of eight ect sessions , his world destruction fantasies , psychomotor excitation , and suicidal ideation were improved . however , since his auditory hallucinations and persecution complex persisted , a second course of eight treatment sessions was administered , which ameliorated the remaining psychiatric symptoms .
after the 16th ect session , brain mri was performed to determine whether organic brain disease was present , and there was no sign of brain disease or bleeding .
a task force report of the american psychiatric association ( apa)4 has suggested that there are no absolute contraindications to ect , but that recent stroke , cerebrovascular malformations , and space - occupying intracranial lesions are related to an increased risk of intracranial hemorrhage due to ect .
this apa statement may have discouraged psychiatrists from performing ect on patients with bleeding tendencies such as in hemophilia .
mehta et al5 reported the results of a study of 35 patients receiving warfarin , an anticoagulant inhibiting the synthesis of vitamin k - dependent clotting factors such as factors ii , vii , ix , and x. the extrinsic clotting system is impaired in patients with hemophilia a , and warfarin extends the intrinsic and extrinsic clotting systems . in the study , international normalized ratio values measured on the day of ect varied notably , including subtherapeutic , therapeutic , and supratherapeutic .
glaub et al2 demonstrated that ect could be performed without bleeding or other complications when patients with hemophilia a were pre - treated with factor viii concentrates .
our report shows the safety of ect for patients with hemophilia a when they are supplemented with coagulation factor viii .
patients with hemophilia can even undergo open surgery6 with appropriate management of the condition with coagulation factors .
thus , although only two patients with hemophilia a have successfully received ect , evidence suggests that patients with hemophilia can be safely treated with ect if pretreated with factor viii . in conclusion ,
when a patient with hemophilia a is pre - treated with factor viii , ect may be performed safely . for patients with hemophilia

Answer:
electroconvulsive therapy ( ect ) is used for medication - resistant and life - threatening mental disorders , and therefore it occupies an important position in psychiatric treatment .
 ect reportedly increases intracranial pressure and is suspected of increasing the risk of intracranial hemorrhage , especially in patients with hemorrhagic diseases such as hemophilia .
 a decrease in or loss of blood coagulation factors , including factor viii and factor ix , are found in hemophilia a and b , respectively .
 psychiatrists may hesitate to perform ect on patients with bleeding tendencies , such as in hemophilia . here , we report the successful use of ect on a neuroleptic - resistant patient with schizophrenia and severe hemophilia a. we performed ect 16 times supplemented with coagulation factor viii to prevent intracranial and systematic hemorrhage . we administered factor
 viii concentrates to the patient to keep factor viii activity at 30%40% during ect .
 the patient did not show bleeding or other complications during the ect sessions .
 we suggest that pretreatment with factor viii can help manage the increased risks of intracranial and systematic bleeding during ect that is present in patients with hemophilia a. the present report supports the idea of performing ect safely on patients with hemophilia a by administering factor viii .


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:
although great enthusiasm exists for developing skills in laparoscopic urology in the united kingdom , training opportunities are limited .
this is primarily due to a lack of approved urology / laparoscopy fellowships , as exist in the united states .
it is an unfortunate fact that many interested urologists do not progress beyond the initial courses stage and indeed a number of urologists who have attended animal laboratory training as well have not proceeded to regular urological laparoscopic practice .
fellowship , enabling supervised training so that interested urologists could become comfortable and competent with laparoscopic urology .
the fellowship program is available to those who have completed the 2 initial training steps , ie , basic / advanced training courses and an animal laboratory course .
prior practice on simulators using laparoscopic instruments is encouraged to enable the trainees to get the most out of their time spent with the mentor in the clinical setting .
basic training is centered on the development of familiarity with the safe handling of laparoscopic instrumentation and stereoscopic skills in the dry laboratory setting .
advanced training involves a series of formal lectures followed by practice sessions in the animal laboratory ; attendees are also shown live surgery via video links .
skills training is assessed by the mentor in these phases by objectively marking the achievement of various predetermined parameters that evaluate safe acquisition of laparoscopic skills like clipping and suturing .
the fellowship program steps are broadly similar thereafter , but individual variations may occur , depending on the distance that the trainee has to travel and availability of the mentor .
an honorary contract is raised for the trainee at the mentor hospital ; the trainee then observes the mentor perform 4 or 5 laparoscopic renal procedures and may assist with the same by acting as the camera driver for these cases .
if possible , trainees then refer cases suitable for laparoscopic surgery to the mentor ; this helps gestate the necessary workload .
the first 4 cases that are performed by the trainee are usually hand - assisted simple or radical nephrectomies , and the aim is to perform at least a case a week at a dedicated theater session with the possibility of adding in more cases as appropriate .
the trainee then goes on to perform conventional laparoscopic cases , again under mentor supervision , with the mentor initially acting as camera driver .
this program duration varies but is approximately 4 to 5 months , primarily due to the paucity of clinical material available in any one unit at a time , and secondly , to fit in with other work commitments .
mentors are then awarded an honorary contract at the trainees ' hospital to supervise the trainees during their first few cases therein .
trainees schedule simple cases initially and gradually increase the level of difficulty as their skills and confidence improve .
six of them are in independent laparoscopic urological practice , and the others are in phase 6 or above .
trainee one started this program in september 2000 and observed 4 simple nephrectomies and 1 radical nephrectomy before proceeding to phase 6 .
because of the distance involved , the mentor condensed stages 4 and 5 and performed 12 cases with the trainee at the trainee 's hospital before the trainee entered independent practice . since then , he has performed 14 unsupervised laparoscopic urological procedures .
trainee two started the program in may 2001 and has performed 10 procedures with the mentor ; he was fortunate to obtain further hands - on training abroad , which helped shorten his training .
trainee three , four , five , and six started the program in may 2002 and performed 10 procedures each with the mentor , before commencing unsupervised practice .
trainees seven , eight , and nine are making steady progress , currently performing hand - assisted procedures with the mentor who is offering support and advice without actually being scrubbed in for the procedure .
it is anticipated that over the next few months trainees seven , eight , and nine will adopt independent practice .
skills development in all cases was steady , with a progressive increase in dexterity and improvement in spatial orientation .
for the neophyte laparoscopist , it is indeed a great leap of faith that has to be taken from the animal laboratory to the human arena ; we perceive the main stumbling block to be a lack of direct mentor / trainee supervision .
this program was designed to allow skill and confidence building under the direct supervision and guidance of experienced laparoscopic urologists , as initially suggested by shalhav . in effect , this reduces the conversion rate and complications that otherwise could be a major issue ; therefore , the transition to independent urological practice appears to be smoother .
we also believe that the selective use of hand assistance early in the program helps build confidence and aids in development of 3-dimensional spatial orientation ; secondly , the ability to directly apply digital pressure exists in case of unexpected vascular injury .
once trainees are facile with hand - assisted laparoscopic practice , they are then encouraged to move on towards pure laparoscopic and retroperitoneoscopic procedures ; all trainees agreed that the initial phase helped them make the transition more easily .
the case load at one particular hospital may not be enough to enable concentrated dissemination of laparoscopic skills . as a result ,
sometimes trainees have had to spend up to 4 weeks on occasion without performing a single laparoscopic case ; this in turn has a bearing on the length of the fellowship program .
it is not easy to put a finite number onto the number of mentored cases that would have to be performed by trainees before proceeding to independent practice because this appears to depend on innate skills , but 10 cases would seem to approximate an acceptable mean .
some trainees have had to forfeit other obligations for the duration of the fellowship , which they could not have done without support from their colleagues and the management in their respective hospitals .
we acknowledge unstinting support from anaesthetic colleagues , given the fact that anaesthetic / procedure time needs to be acceptable ; this has obviously not always been the case when a new trainee joins the fellowship program .
this program seeks to help safely relocate the teaching of laparoscopy from the lecture hall and animal laboratory to the clinical setting , and , in doing so , we hope to accelerate the training of interested , qualified urologists over the next few years . residents and fellows are being trained in laparoscopic urology now ; as a result , this fellowship may be phased out in the future ; until this noticeable lacuna in training is filled , we would wish to continue to offer this training to interested consultant urologists .
a one - on - one fellowship program enables rapid , safe , and effective laparoscopic skills acquisition by established urologists .

Answer:
objectives : a fellowship training model in laparoscopic urological surgery has been established for interested urologists to help them proceed from the pelvic trainer/ animal laboratory environment to safe clinical practice .
 the objective of the model is to provide trainees with clinical experience under direct mentor supervision before embarking on independent laparoscopic urological surgery at their own base hospitals.methods:the fellowship model incorporates 9 fluid phases : phase 1 to complete basic and advanced training courses .
 phase 2 to practice at home or in the office using pelvic trainers .
 phase 3 to proceed to an animal laboratory course .
 phase 4 to visit centers of international repute to observe high - volume laparoscopic urology .
 phase 5 to observe the mentor perform several major renal laparoscopic cases .
 phase 6 to perform several hand - assisted renal procedures under direct mentor guidance at the mentor hospital .
 phase 7 to perform several laparoscopic or retroperitoneoscopic renal procedures , or both , under direct mentor guidance at the mentor hospital .
 phase 8 to mentor assisted trainees to start laparoscopic surgery at their own hospitals .
 phase 9 to practice laparoscopic urology independently.results:so far , 9 trainees have participated in the fellowship .
 six have reached phase 9 with independent practice , 2 others are in phase 8 , and 1 is in phase 7 .
 skills development has been steady , with progressive acquisition of surgical dexterity and spatial orientation.conclusion:this fluid fellowship model provides urologists with clinically applicable teaching experience to learn a relatively new surgical concept safely and effectively , thereby promoting clinical governance . it may be possible for other centers to establish similar fluid  mini  fellowships to help disseminate laparoscopic surgical skills .


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:
ventriculoperitoneal ( vp ) shunting is commonly utilized as a diversion procedure for patients with hydrocephalus .
multiple techniques for initial placement of the catheters have been described , including conventional minilaparotomy , peel - away introducer sheaths , as well as full laparoscopic approaches .
vp shunts fail for a variety of reasons , including failure secondary to disconnection of abdominal tubing with migration of the tubing , most commonly further into the peritoneal cavity ; this occurs in 2.5% to 4% of shunts placed according to current published series .
initial shunt failure rates continue to be high , with a reported failure rate of 31% at 6 months and an infection rate of 7% .
common presenting features of shunt failure include headache , mental status changes , and vomiting .
laparoscopy avoids laparotomy and may provide improved confirmation of shunt functionality and placement at the time of revision .
a 31-year - old obese female was initially treated for pseudotumor cerebri with placement of a lumbar peritoneal shunt in 2003 .
after 5 failed revisions for nonfunction , a ventriculoperitoneal shunt was placed in september 2007 .
the patient subsequently presented 11 days postoperatively with headaches , dizziness , and formation of a seroma in her right upper quadrant .
ct scan revealed the vp catheter tubing coiled in the subcutaneous tissue of the right upper quadrant .
four 5-mm titanium clips were placed on the catheter in an attempt to prevent repeated migration of the tubing .
one month later , the patient presented with recurrence of headaches , nausea , and right upper quadrant abdominal pain .
ct scan was again obtained , revealing that the shunt tubing had migrated back into the subcutaneous tissue ( figure 1 ) .
a laparoscopic approach was again utilitzed for retrieval and attempted improved fixation of the vp shunt .
adhesions were taken down at the original entry site of the shunt , revealing a 2-cm fascial defect in the abdominal wall with the shunt tubing coiled within it ( figure 2 ) .
the tubing was brought down through the defect out of the subcutaneous space and into the peritoneal cavity ( figure 3 ) .
one port was upsized to 10 mm , and the tubing was externalized through the port and secured to a 3-cm x 10-cm piece of ptfe mesh with 30 prolene sutures ( figure 4 ) .
csf flow was confirmed , and the tubing attached to the mesh was reintroduced into the peritoneal cavity .
the mesh was secured to the abdominal wall by using spiral tacks and 0 gore - tex sutures ( figure 5 ) .
the separate 2-cm fascial defect was repaired with a 10-cm x 10-cm piece of ptfe mesh placed as an onlay with the vp shunt exiting from its inferior border .
it was secured with spiral tacks and 0 gore - tex sutures for transabdominal fixation ( figure 6 ) .
the patient was seen in follow - up 7 months postprocedure and reported no recurrence of her symptoms .
traditionally , laparotomy was necessary for both peritoneal shunt placement as well as subsequent shunt revisions .
the advent of laparoscopy has afforded a minimally invasive approach that has resulted in decreased patient morbidity related to shunt placement .
retrieval and repositioning of a displaced vp shunt in the peritoneal cavity using laparoscopic techniques has been previously described . in the present case ,
our subsequent laparoscopic approach utilized ptfe mesh , well described in the use of laparoscopic ventral hernia repair , to fixate the tubing to the abdominal wall to prevent further tubing migration .
this approach also allowed us to simultaneously repair the fascial defect associated with the shunt entry site into the peritoneal cavity , allowing us to reap the benefits of decreased recurrence and decreased patient morbidity associated with this technique .
the technique described was well tolerated without complication and resulted in improvement of clinical symptoms .

Answer:
a 31-year - old female with a history of pseudotumor cerebri presented with headache and abdominal discomfort after placement of a ventriculoperitoneal ( vp ) shunt .
 the vp shunt was placed after prior failure and revision of a lumbar peritoneal shunt .
 computed tomography demonstrated shunt migration into the subcutaneous tissue .
 laparoscopy was used to reposition the vp shunt , directing the shunt toward the pelvis .
 the patient presented for further evaluation one month later , at which point the shunt was shown to have migrated into the subcutaneous tissue once again .
 laparoscopy was again used to reposition the shunt and affix it to the abdominal wall by using polytetrafluoroethylene ( ptfe ) mesh .


Question:
You will be shown the title of a chemistry paper, together with sections excerpted from the body of the paper. The paper sections may include HTML tags like `<p>` and `</p>`; please ignore these. Your task is to write an abstract for the paper. Your response should include the abstract and no other text.

Title:
A computational study of the Hofmann elimination pathway for the Morita-Baylis-Hillman reaction under DABCO catalysis. Participation of a bridge-head ylide

Paper sections:

We have carried out a computational study of the Me3N-catalyzed MBH reaction and recently reported an alternate overall lower energy pathway. 4 This pathway involved proton-transfer in the aldol product through a seven-centred cyclic transition state structure, followed by Hofmann elimination to form the observed product and also regenerate the catalyst as shown in Scheme 2. TS1, TS2, TS3 and TS4 represent, respectively, the transition states for conjugate addition of Me3N to cyclopentenone to form an enolate 3, aldol reaction of the enolate with acetaldehyde to form the oxyanion 5, proton-transfer from one of the methyl groups on N to the oxyanion to form 6b and Hofmann elimination to generate the MBH product 7. The energy required to achieve TS2 was merely 2.6 kcal/mol and, likewise, the activation energy for the Hofmann elimination, 9.3 kcal/mol, was significantly lower than that for the proton-transfer through four-centred cyclic TS structure, 24.2 kcal/mol, which is accompanied immediately with E1cB elimination.

Scheme 2. The proposed reaction pathway for the MBH reaction of cyclopentenone and acetaldehyde catalyzed by trimethylamine

Having shared the finding with a good colleague, 5 concern was raised as to whether the same was permissible with DABCO (1,4-diazabicyclo[2.2.2]octane) also because it would have to generate a bridge-head zwitterion. A truly genuine concern as it was, we felt wanted to investigate a parallel of the Me3N-catalyzed reaction by using DABCO as the catalyst.

Computational methods. All the structures, geometry optimizations and TS structure searches were carried out using the global hybrid meta-GGA M06-2X density functional and 6-311++G(d,p) basis set at 298.15 K. 6 The optimized structures were verified as minima or first order saddle points on their potential energy surfaces by harmonic vibrational frequency analysis. Calculations were carried out using the Gaussian 16 suite of programs. 7

Results and Discussion. We approached the problem by first studying the simpler DABCO, N-methyl-DABCO and the ylide formed from deprotonation at the position adjacent to the bridge-head. The computed structures of the two species are given in Figure 1. The difference in the structures is in the shape of the ring which is a clear boat in DABCO and N-methyl-DABCO, and twist-boat in the ylide.

The survival of the bride-head ylide as a stable structure instilled confidence in us to proceed and estimate the entire reaction profile of the MBH reaction of cyclopentenone with acetaldehyde catalyzed by DABCO. The reaction profile of the DABCO-catalyzed reaction is given in Figure 2. This profile is much similar to the Me3N-catalyzed reaction in every respect. In particular, the activation free energy for (a) the proton-transfer through seven-centred cyclic TS structure is 2.4 kcal/mol against the 2.6 kcal/mol under Me3N-catalysis, (b) the Hofmann elimination is 11.2 kcal/mol against the 9.3 kcal/mol under Me3N-catalysis, (c) the aldol reaction is 39.8 kcal/mol against the 41.9 kcal/mol under Me3N-catalysis, (d) the conjugate addition is 27.7 kcal/mol against the 29.6 kcal/mol under Me3N-catalysis, and (e) the proton-transfer through four-centred cyclic TS structure, as in the conventional mechanism, is 25.0 kcal/mol against the 24.2 kcal/mol under Me3N-catalysis. The aldol reaction continues to be the rate-limiting reaction in the entire sequence. However, a remarkable feature to note in here is the lower activation free energy of the DABCO-catalyzed aldol reaction than the Me3N-catalyzed reaction by 2.1 kcal/mol. The DABCO-catalysis is, therefore, expected to result in a faster reaction than Me3N-catalysis.

We have calculated the deuterium isotope effects, KH/KD, for the conventional route involving protontransfer through a four-centred cyclic transition state structure and the present Hofmann elimination route and found it to be 1.36 in each instance. Several MBH reactions under solvent-less conditions have been reported in the literature and often found to be faster and superior yielding than the reactions in solvents. 8

Conclusion.

The DABCO-catalysis of MBH reaction parallels the catalysis by Me3N and the perceived difficulty of generating a bridge-head zwitterion is just not there as anticipated from the preliminary investigations on the structural aspects of N-methyl-DABCO and the consequent bridge-head ylide.

The DABCO-catalyzed Hofmann elimination pathway for the MBH reaction is also lower in energy than the conventional pathway requiring proton-transfer through a four-centred cyclic TS structure to form a species ready for E1cB elimination. Also, for lowering the activation free energy of the rate-limiting aldol reaction by 2.1 kcal/mol, DABCO is expected to result in a faster reaction than Me3N.

The study of the influence of solvents 9 on the overall reaction profile and the associated kinetic isotope effect kH/kD is under investigation.

Supporting Information

Supporting Information (SI) available: Cartesian coordinates of the optimized substrates, transition state structures, Gibbs' free energies of the ground and transition state structure studied at the level M06-2X/6-311++G(d,p).

ORCID

Veejendra K. Yadav: 0000-0001-8294-0677

Answer: In comparison to the popular pathway involving proton-transfer via a four-centred cyclic transition state structure, the recently proposed overall lower energy pathway involving protontransfer via a seven-centred cyclic transition state structure followed by Hofmann elimination for the Me3N-catalyzed Morita-Baylis-Hillman reaction is applicable to the DABCO-catalyzed reaction equally well. This finding clearly establishes that the zwitterion at the bridge-head in DABCO is well tolerated. Also, the activation free energy of the rate-limiting aldol reaction under DABCO-catalysis is lower than that under Me3N-catalysis, suggesting that DABCO is likely a better catalyst to achieve faster conversion.Introduction. The Morita-Baylis-Hillman (MBH) reaction, Scheme 1, is a broad range, synthetically useful chemical transformation allowing the construction of a myriad of densely functionalized methylene--hydroxy derivatives. 1,2 The reaction involves coupling of an electrophile, such as an aldehyde, with an activated alkene (normally with an electron-withdrawing group) in the presence of a Lewis base catalyst such as Me3N, DABCO and DBU. Based on its atom economy and feasibility, the MBH reaction is regarded as one of the most efficient transformations in organic chemistry. 3 According to the generally accepted mechanism, the aldol product 5 undergoes a proton-transfer reaction by the way of a four-centred cyclic transition state (TS) structure, as shown, to form the 1,3-zwitterion 6a, which falls through E1cB elimination, as shown, to the MBH product 7 and also regenerate the Lewis base to allow it re-enter the reaction cycle. The reaction, therefore, is catalytic in the Lewis base.Scheme 1. The generally accepted pathway for the Me3N-catalyzed MBH reaction of cyclopentenone with acetaldehyde


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:
this study reports a rare patient of a rapid spontaneously resolving acute subdural hematoma . in addition
, an analysis of potential clues for the phenomenon is presented with a review of the literature .
a 1-year - and-2-month - old boy fell from a height of approximately 2 m. the patient was in a superficial coma with a glasgow coma scale of 8 when he was transferred to the authors hospital .
computed tomography revealed the presence of an acute subdural hematoma with a midline shift beyond 1  cm .
repeat imaging after 15  hours showed the evident resolution of the hematoma and midline reversion .
progressive magnetic resonance imaging demonstrated the complete resolution of the hematoma , without redistribution to a remote site .
even though this phenomenon has a low incidence , the probability of a rapid spontaneously resolving acute subdural hematoma should be considered when patients present with the following characteristics : children or elderly individuals suffering from mild to moderate head trauma ; stable or rapidly recovered consciousness ; and simple acute subdural hematoma with a moderate thickness and a particularly low - density band in computed tomography scans .
a 1-year - and-2-month - old boy fell from a height of approximately 2 m and lost consciousness after he experienced head trauma .
the patient was sent to a local hospital immediately . during the interval emergent computed tomography ( ct ) , the patient vomited several times .
1a ) revealed a right frontotemporal asdh that was approximately 9  mm in size with a subarachnoid hemorrhage in the longitudinal fissure and midline shift beyond 10  mm .
he was in a superficial coma with the same gcs score that was documented in previous medical records .
both of the patient 's pupils were equal in size 2  mm but exhibited a blunted response to light .
1b ) showed a decrease in hematoma density and diffuse cerebral edema with obviously squeezed ventricles ; the midline was still deviated compared with the first ct scan .
given his consciousness and imaging findings , intracranial pressure monitoring was preferred . even though the laboratory features were not surgical contraindications , the boy 's guardians refused the placement of an intracranial pressure probe or a craniotomy .
general monitoring aimed to maintain sao2 at > 95% , mean systolic blood pressure at > 90 mm hg , temperature at < 37c , and paco2 at 35 to 40 mm hg . owing to the lack of an accurate intracranial pressure assessment
, mannitol was administered empirically at 0.5  g / kg every 6  hours . the third ct scan ( fig .
1c ) revealed evident resolution of the hematoma and midline shift improvement , with only a subarachnoid hemorrhage present in the posterior longitudinal fissure 24  hours after the trauma . after he had received 2 days of conservative management , the boy regained consciousness .
c ) showed that the asdh was almost completely resolved on the fourth day after admission , without redistribution to the upper cervical spinal cord .
( a ) initial ct scan revealed right frontotemporal acute subdural hematoma ( arrow to show ) , with sah in anterior longitudinal fissure and midline shift exceeding 10  mm .
( b ) a second ct scan showed the decrease of hematoma ( arrow to show ) with obvious diffusion cerebral edema .
( c ) a third ct scan was taken after 24  hours of the injury revealed an evident resolution of hematoma ( arrow to show ) and midline revert with only sah left in posterior longitudinal fissure .
ct , computed tomography ; sah , subarachnoid hemorrhage . magnetic resonance imaging on the fourth day of conservative management .
transverse ( a ) , sagittal ( b ) , and coronal ( c ) planes were performed which revealed acute subdural hematoma complete resolution without redistribution to upper cervical spinal cord .
the following 2 possible explanations were proposed : the asdh was diluted and washed out by cerebrospinal fluid ( csf ) after the tearing of the arachnoid membrane and the hematoma was redistributed to the subdural space .
wong et al measured the hounsfield units of the subarachnoid space , which was close to normal , and confirmed the redistribution of a hematoma to the subdural space then to the subarachnoid space .
the theory was based on the flow of liquefied blood , which was thought to be driven by the change in intraparenchymal pressure . in those patients without available definitive evidence of blood redistribution , csf flushing seems more likely .
based on table 1 , rapid resolution occurred more frequently in children , less frequently in elders , and least often in middle - age individuals . in children and elders ,
asdh is often caused by mild or moderate injuries , such as falling or slipping .
in elderly individuals , brain atrophy and a wide cavum of the subarachnoid space can cause an arachnoid membrane slit under external force . for middle - age individuals , well - developed brain tissue and narrow compensatory space results in an arachnoid membrane that is comparatively difficult to tear with a mild injury .
wen et al proposed that gcs was higher than 8 in patients who exhibited this phenomenon .
however , in table 1 , 7 of 18 patients exhibited a gcs score of less than 8 , and the minimum was 5 . in the process of the clinical evaluation ,
the dynamic change in consciousness is a more heavily weighted factor to consider than the initial gcs score . according to a review of all patients ( table 1 ) , most of those patients regained consciousness quickly .
although some of those patients did not regain consciousness quickly , their conditions were stable . in our case ,
the patient 's consciousness improvement was even slower than the time of resolution according to the ct scan .
thus , by comparing the initial gcs score after head trauma , we inferred that a rapid recovery or relative stabilization of consciousness is more persuasive in these patients .
the evaluation of images from ct scans that were performed during different phases of our patient clearly demonstrated the rapid transition of hematoma density from a high density to a mixed density .
some authors agreed that the potential sign in early ct of a rapid resolution was the presence of a low - density band . in our patient 's second ct scan ( fig .
1b ) , it was observed that remarkable cerebral edema could squeeze , in some way , the diluted hematoma .
kuroiwa et al suggested that diffuse cerebral edema was necessary for the spontaneous resolution of a hematoma .
we speculate that cerebral edema leads to resolution via both mechanisms , but it may not be the prerequisite for hematoma rapid resolution . indeed ,
in most patients , the diffuse edema was not even observed ( table 1 ) .
we propose that the slice or middle thickness hematoma ( < 1.5  cm ) would be suitable in the consideration of rapid resolution .
lee et al reported a patient with a hematoma thickness that was larger than 2.5  cm , yet it finally converted to a chronic subdural hematoma .
the presence of simple asdh without contusion appears to be associated with rapid resolution . we suspect that this effect is due to the mass effect of the contusion , which impeded the flow of csf in the limited space .
this patient has been reported because of clear evidence of csf dilution and a flush effect that led to resolution of the hematoma , and the finding that a distinctly swollen brain probably accelerated the process .
there is no need for the deliberate evaluation of the phenomenon as a coincidence during treatment .
we suggest that asdh rapid resolution should be considered when patients present with the following characteristics : children or elders suffering from mild to moderate head trauma ; stable or rapidly recovered consciousness ; and simple asdh with moderate thickness and a particularly low - density band in ct scan images .

Answer:
introduction : this study reports a rare patient of a rapid spontaneously resolving acute subdural hematoma . in addition , an analysis of potential clues for the phenomenon is presented with a review of the literature.patient presentation : a 1-year - and-2-month - old boy fell from a height of approximately 2 m. the patient was in a superficial coma with a glasgow coma scale of 8 when he was transferred to the authors hospital .
 computed tomography revealed the presence of an acute subdural hematoma with a midline shift beyond 1  cm .
 his guardians refused invasive interventions and chose conservative treatment .
 repeat imaging after 15  hours showed the evident resolution of the hematoma and midline reversion .
 progressive magnetic resonance imaging demonstrated the complete resolution of the hematoma , without redistribution to a remote site.conclusions:even though this phenomenon has a low incidence , the probability of a rapid spontaneously resolving acute subdural hematoma should be considered when patients present with the following characteristics : children or elderly individuals suffering from mild to moderate head trauma ; stable or rapidly recovered consciousness ; and simple acute subdural hematoma with a moderate thickness and a particularly low - density band in computed tomography scans .