Melricflash/CW_MedAbstractsAlt huggingface dataset:
Norwalk virus genome cloning and characterization. Major epidemic outbreaks of acute gastroenteritis result from infections with Norwalk or Norwalk-like viruses. Virus purified from stool specimens of volunteers experimentally infected with Norwalk virus was used to construct recombinant complementary DNA (cDNA) and derive clones representing most of the viral genome. The specificity of the clones was shown by their hybridization with post- (but not pre-) infection stool samples from volunteers infected with Norwalk virus and with purified Norwalk virus. A correlation was observed between the appearance of hybridization signals in stool samples and clinical symptoms of acute gastroenteritis in volunteers. Hybridization assays between overlapping clones, restriction enzyme analyses, and partial nucleotide sequence information of the clones indicated that Norwalk virus contains a single-stranded RNA genome of positive sense, with a polyadenylated tail at the 3' end and a size of at least 7.5 kilobases. A consensus amino acid sequence motif typical of viral RNA-dependent RNA polymerases was identified in one of the Norwalk virus clones. The availability of Norwalk-specific cDNA and the new sequence information of the viral genome should permit the development of sensitive diagnostic assays and studies of the molecular biology of the virus. 

Category: digestive system diseases
Recent trends in cesarean section use in California. Cesarean section use in the United States has increased to 24.7% of deliveries in 1988 and is the most common hospital surgical procedure. California cesarean section rates were examined to measure recent trends in obstetric practices and to project future patterns of cesarean section use. Using discharge abstracts from 1983 to 1987 California hospital deliveries, total cesarean section rates were found to increase from nearly 22% in 1983 to 25% in 1987, an increase of 15%. Using a series of least-squares regression models, time trends in the distribution of indications associated with cesarean section among all deliveries and indication-specific cesarean section rates were evaluated. Increases in the number of women with previous cesarean section and fetal distress contributed to rising cesarean section rates. In addition, indication-specific cesarean section rates increased for breech presentation and dystocia. These trends were counterbalanced, in part, by declining rates of repeat cesarean sections. Trends noted for July 1985 through 1987 did not differ substantially from those observed for January 1983 to June 1985, suggesting that recent policy attempts to alter cesarean section use have not had a measurable effect on existing trends. Projections suggest that California cesarean section rates will rise to a level of 34% by the year 2000. 

Category: general pathological conditions
Mucosal characteristics of pelvic ileal pouches. This study aimed to investigate the degree of colonic metaplasia in ileo - anal pouches. Biopsy specimens from 25 patients with functioning pouches, eight of whom had pouchitis, were studied using routine histology, mucosal morphometry, mucin histochemistry, and immunoperoxidase staining with monoclonal antibodies directed towards a 40kD colonic protein and a small bowel specific disaccharidase-sucrase isomaltase. Thirteen patients (including all eight with pouchitis) had subtotal or total villous atrophy and crypt hyperplasia. In this group, nine had colorectal type sulphomucin and the 40kD colonic protein was detected in two. These changes were not observed in patients with less severe villous abnormalities. Sucrase-isomaltase activity was, however, present in all 25 pouch specimens. We conclude that although some ileal pouches acquire certain colonic characteristics, complete colonic metaplasia does not occur. 

Category: digestive system diseases
Relative validity of self-reported snoring as a symptom of sleep apnea in a sleep clinic population The purpose of this study was to evaluate the relative validity of responses to three different questions about snoring as indicators for sleep apnea in a population referred to a sleep clinic. Secondary goals were to evaluate the meaning of a "don't know" response to these questions and to examine how the associations between snoring and sleep apnea are influenced by demographics. Results from 1,409 patients in a sleep clinic indicated that nearly all levels of estimated snoring frequency were associated with a greater likelihood of sleep apnea. In addition, a "don't know" response indicated a likelihood of sleep apnea. In the sample from this clinic, sensitivities approximating 90 percent were obtained in men, and specificities approximating 90 percent were obtained in women, but high diagnostic accuracy (high specificity in men; high sensitivity in women) could not be achieved with the three snoring questions used here. Generally, associations between snoring and sleep apnea were independent of age and sex. Single persons, persons living alone, and persons customarily sleeping alone of both sexes all showed associations between self-reported snoring and the presence of sleep apnea. 

Category: general pathological conditions
Diagnostic quality and complications of hysterosalpingography: oil- versus water-soluble contrast media--a randomized prospective study. In a prospective randomized study of 417 patients, side effects and complications of contrast media and the diagnostic quality of images obtained after hysterosalpingography (HSG) were evaluated after use of diatrizoate meglumine (104 patients), ioxaglate (105 patients), iohexol (105 patients), or ethiodized poppy-seed oil (103 patients). The authors detected no differences among these groups in the prevalence of pain during HSG. The prevalence of lower abdominal pain and vaginal bleeding after HSG was significantly lower in the group that received ethiodized poppy-seed oil than in the three other groups. The prevalence of pelvic infection or inflammation was significantly lower with ethiodized poppy-seed oil than with water-soluble media. All contrast media provided acceptable diagnostic image quality with regard to fallopian tubes, peritoneal spill, and intraperitoneal distribution. Visualization of the uterine cavity and ampullary rugae was significantly better with water-soluble media than with ethiodized poppy-seed oil, which was associated with a high conception rate and which the authors consider preferable for HSG. 

Category: nervous system diseases
Magnetic resonance imaging--the evaluation of choice in residual shunt after congenital heart disease surgery? Accurate anatomic diagnosis presents a dilemma in patients with residual shunt after corrective surgery for congenital heart disease. We describe a patient who, after atrial septal defect repair, developed dyspnea and central cyanosis despite normal pulmonary arterial pressures and right heart chamber size. A role for early MRI is suggested. 

Category: general pathological conditions
Glutathione disulfide formation and oxidant stress during acetaminophen-induced hepatotoxicity in mice in vivo: the protective effect of allopurinol. Acetaminophen (500 mg/kg i.p.) induced hepatotoxicity in fasted ICR mice in vivo. Acetaminophen also caused a long-lasting 50% reduction of the hepatic ATP content, an irreversible loss of hepatic xanthine dehydrogenase activity and a transient increase of the xanthine oxidase activity. All effects occurred before parenchymal cell damage, i.e., the release of cellular enzymes. The hepatic content of GSH and GSSG was initially depleted by acetaminophen without affecting the GSSG:GSH ratio (1:200), however, during the recovery phase of the hepatic GSH levels the GSSG content increased faster than GSH, resulting in a GSSG:GSH ratio of 1:18 24 h after acetaminophen administration. The mitochondrial GSSG content increased from 2% in controls to greater than 20% in acetaminophen-treated mice. The extremely elevated tissue GSSG levels were accompanied by a 4-fold increase of the plasma GSSG concentrations but not by an enhanced biliary efflux, although hepatic GSSG formation and biliary excretion were not affected by acetaminophen. Allopurinol protected dose-dependently against acetaminophen-induced cell injury, the loss of ATP and the increase of the GSSG content in the total liver and in the mitochondrial compartment without inhibiting reactive metabolite formation. High, protective as well as low, nonprotective doses of allopurinol almost completely inhibited hepatic xanthine oxidase and dehydrogenase activity, but only high doses prevented the increase of the mitochondrial GSSG content. The data indicate a long-lasting, primarily intracellular oxidant stress during the progression phase of acetaminophen-induced cell necrosis. The protective effect of allopurinol is unlikely to involve the inhibition of reactive oxygen formation by xanthine oxidase but could be the result of its antioxidant property. 

Category: digestive system diseases
Treatment of chronic relapsing inflammatory demyelinating polyneuropathy by cyclosporin A and plasma exchange. A case report. A patient with chronic relapsing inflammatory demyelinating polyneuropathy was successfully treated with plasma exchanges and cyclosporin A (CsA). Dynamometric measurements of hand force during the time of CsA treatment showed a highly significant correlation between hand force and CsA blood levels. The largest influence of CsA on hand force occurred 11-13 days after CsA uptake. 

Category: nervous system diseases
Definition of the role of contemporary surgical management in cisternal and parenchymatous cysticercosis cerebri. With increasing immigration from endemic regions, the incidence of neurocysticercosis in North America is rising. This retrospective study was undertaken to examine the role of surgery in those cases presenting with large cystic parenchymal and cisternal lesions in the current era of anthelminthic agents administered orally. A total of 237 patients presented with newly diagnosed neurocysticercosis to our institution over a recent 5-year period (mean age, 31.2 years). Among those who presented with cystic mass lesions predominantly affecting the brain parenchyma and cisternal spaces, 20 (8.4%; mean age, 40.2 years) with large cystic lesions subsequently underwent surgical intervention, either because of an emergent presentation or because they were refractory to medical management. Clinical presentation included increased intracranial pressure, focal neurological deficit, and seizure. Radiographic imaging (computed tomography and/or magnetic resonance imaging) demonstrated 12 cases with cisternal lesions, 7 with parenchymal lesions, and 1 involving both compartments. Based on imaging guidelines, 30 operative procedures (excluding shunt revisions) were performed (14 craniotomies, 8 cerebrospinal fluid diversions, 7 stereotactic procedures, and 1 burr hole drainage). Fifteen (75%) showed neurological or symptomatic improvement over a median follow-up period of 36.4 months. There were three surgery-related complications and no deaths. 

Category: nervous system diseases
Hyperadrenergic orthostatic intolerance as a result of postpartum blood loss. This article describes a young women in whom orthostatic intolerance developed as a result of protracted postpartum vaginal bleeding. The cardiovascular abnormalities were unresponsive to usual treatment measures, and she required combination therapy directed at increasing plasma volume and decreasing sympathetic nervous system activity. After resolution of her symptoms, the patient required no long-term therapy. Chronic blood loss has not been reported as a cause of this syndrome. 

Category: general pathological conditions
Diclofenac-associated hepatotoxicity Diclofenac sodium, a phenylacetic acid-derived nonsteroidal anti-inflammatory drug (NSAID) recently released in the United States, was associated with the development of significant hepatitis in seven patients, with one associated death. Signs and symptoms developed within several weeks of initiation of drug use and generally resolved 4 to 6 weeks following discontinuation of use of the drug. The only patient rechallenged with the drug developed a recurrence of her hepatic abnormalities. In one patient, fatal, fulminant hepatitis developed despite early withdrawal of the drug. Review of the European literature disclosed three additional fatalities associated with diclofenac therapy. It is unclear whether the incidence of hepatotoxicity is higher with this drug compared with other nonsteroidal anti-inflammatory drugs. Careful patient monitoring is advised, and prompt discontinuation of the drug is suggested when signs or symptoms of liver disease develop. 

Category: nervous system diseases
Intracranial complications of paranasal sinusitis: a combined institutional review. Intracranial complications of paranasal sinusitis constitute true surgical and medical emergencies. The charts of all patients (n = 649) admitted for acute or chronic sinusitis to the University of Minnesota Hospital and to the University of Michigan Medical Center during a 13-year period (1975 to 1988) were retrospectively reviewed to determine the incidence of complications. The clinical presentation, bacteriology, involved sinuses, influencing host factors, white blood cell count on presentation, length of hospitalization, and postinterventional complications are presented. Twenty-four patients with intracranial complications from paranasal sinusitis are studied for an incidence of 3.7%. Aggressive medical and semi-emergent surgical intervention are required to prevent excessive morbidity and/or mortality. Intracranial complications included subdural empyema, frontal lobe abscesses, intrahemispheric abscesses, cavernous and superior sagittal sinus thrombosis, and osteomyelitis. 

Category: nervous system diseases
Preoperative superselective arteriolar embolization: a new approach to enhance resectability of spinal tumors. The extent of surgical resection of spinal tumors is frequently limited by blood loss and technical difficulty associated with the vascularity of the tumors. We report here the use of superselective percutaneous arterial embolization to reduce the rate of blood loss at the time of surgical resection and enhance resectability. The types of tumors treated were metastatic renal carcinoma, metastatic thyroid carcinoma, metastatic melanoma, and giant cell tumor of the sacrum. Two of the patients required repeated embolization and surgery for recurrent symptoms. The estimated blood loss in seven of nine procedures performed on the six patients ranged from 300 to 800 ml, after which no transfusion was required. In two procedures, extensive resection of very large tumors resulted in larger losses of blood, and postoperative transfusion was necessary. No significant complications of embolization or surgery occurred. A key factor in our embolization technique is the use of microfibrillar collagen, which allows occlusion of tumor vessels as small as 20 microns and may prevent reconstitution of the embolized vessels by collateral flow. We conclude that preoperative arterial embolization enhances the resectability of a variety of spinal tumors by reducing intraoperative blood loss. This may provide an additional benefit by reducing the risk related to postoperative transfusion. By permitting a more aggressive surgical approach, the use of preoperative embolization also has the potential to improve outcome in patients with spinal tumors. 

Category: general pathological conditions
Misdiagnosis in patients with amyotrophic lateral sclerosis. To confirm our impression that a high percentage of patients with amyotrophic lateral sclerosis are initially misdiagnosed, we reviewed records of 33 patients with a definitive diagnosis of amyotrophic lateral sclerosis seen over 10 years. Fourteen patients (43%) were initially misdiagnosed. Mean time to correct diagnosis was significantly greater for the misdiagnosed group (16.0 +/- 9.3 months) than for the rest of the patients (7.6 +/- 4.1 months). Two of three patients with an initial symptom of dyspnea were misdiagnosed. Three patients underwent laminectomies because of misdiagnosis. Age, stage of disease, and unusual presenting symptoms were not identified as causes of misdiagnosis. Most likely causes were physicians' failure to consider the diagnosis and lack of familiarity with the common clinical presentations of amyotrophic lateral sclerosis. Earlier diagnosis of amyotrophic lateral sclerosis may help prevent medical mismanagement and may benefit patients both medically and psychologically. 

Category: nervous system diseases
Sunlight and dysplastic nevus risk. Results of a clinic-based case-control study. The dysplastic nevus (DN) is the most important risk factor and precursor for malignant melanoma. The authors compared the responses of 132 consecutive cases of DN, 186 consecutive cases of cutaneous melanoma, and 239 controls attending the same subspecialty clinic to questions regarding sun sensitivity, sun exposure, and other possible risk factors. Dysplastic nevus cases were younger than controls and were of a higher social class, as indicated by more years of formal education. Sun sensitivity (assessed by reported depth of tan after multiple exposures) was associated with both DN risk and melanoma risk after controlling for age and education in logistic regression analysis (P = 0.009 and 0.03, respectively), but for DN risk this association was nonlinear: the relative risks (versus deep tan) were 2.3 for average tanners, 2.8 for light tanners, and 1.6 for those who reported practically no tan. Sun exposure measures were not associated with DN risk after controlling for age and education, whether or not depth of tan was controlled in the analysis. These observations suggest a role for either sunlight or a trait linked with sun sensitivity in the development of dysplastic nevi. 

Category: neoplasms
Acute urinary retention in a child with appendiceal abscess: diagnostic dilemma. Rarely do children with appendiceal abscess present with acute urinary retention as the only sign or symptom. This presentation may delay diagnosis and definitive therapy, thereby causing additional morbidity and possible mortality. We report the eighth case of acute urinary retention in a child associated with an appendiceal abscess. 

Category: digestive system diseases
A histopathologic study of spinal cord ischemia using an isohistogenic rat upper-half-body transplantation model. To study the histopathologic changes of spinal cords exposed to long-duration complete ischemia, the authors developed an upper-half-body transplantation model of inbred rat. In this model, an infant Lewis rat is transplanted to the inguinal region of another adult Lewis rat using microsurgical vascular anastomosis. Even when 2-week-old donor rats were exposed to complete ischemia for 90 minutes, functions of the spinal cord were comparatively preserved. In histopathologic observations, degeneration proportional to complete ischemia duration was noted. In the 60-minute ischemia group of 2-week-old donor rats, however, no substantial differences from normal spinal cord were observed. Under conditions of equal ischemia duration, it appeared the younger animal had the greater ischemic tolerance. 

Category: cardiovascular diseases
Response of angiographically normal and atherosclerotic left anterior descending coronary arteries to acetylcholine. Acetylcholine-induced constriction of human coronary arteries in vivo is commonly attributed to endothelial dysfunction. To examine the effects of 2 other important determinants of vascular responses--namely, agonist concentration and the segment of circulation under study--the diameters of proximal, middle and distal segments of the left anterior descending artery (LAD) and coronary sinus oxygen saturation were measured in 10 patients with angiographically normal coronary arteries (group 1) and in 7 patients with coronary atherosclerosis (group 2) after intracoronary acetylcholine was infused at concentrations from 10(-7)M to between 10(-4)M and 10(-2)M. In group 1, acetylcholine caused minor (less than or equal to 6%) but progressive dilatation of the LAD up to 10(-4)M, but constriction, particularly of the distal segments and tertiary branches, occurred at higher concentrations. Over the same concentration range, coronary sinus oxygen saturation rose progressively from a basal level of 36 +/- 3% to a maximum of 72 +/- 3% in the absence of changes in heart rate and blood pressure, suggesting marked progressive dilatation of resistance vessels. Concentrations greater than or equal to 10(-3)M caused intense constriction of distal epicardial vessels and, in some cases, anginal pain and objective signs of ischemia. Conversely, in group 2, acetylcholine (infused only up to 10(-4)M for ethical reasons) failed to cause significant changes in LAD diameter. These data suggest that the local acetylcholine concentration and coronary vascular segment under study may determine the observed response to at least an equivalent extent as does the presence or absence of coronary atherosclerosis, raising the question of whether a constrictor response to intracoronary acetylcholine reliably indicates the presence of coronary atherosclerosis. 

Category: cardiovascular diseases
Invasive squamous cell carcinoma of the mandible presenting as a chronic osteomyelitis: report of a case. A case of invasive squamous cell carcinoma of the mandible initially thought to be chronic osteomyelitis is reviewed. Discussion of the origin of the tumor and several imaging techniques used for differentiating maxillofacial infection from neoplasm are discussed. The difficulty of diagnosis of chronic painful maxillofacial lesions illustrates the need for a high degree of suspicion concerning any inflammatory lesion not responding to appropriate therapy. Accurate diagnosis and treatment of such lesions most often necessitates microscopic examination. 

Category: neoplasms
L-tryptophan associated eosinophilia-myalgia syndrome. Environmental chemicals are increasingly incriminated in the pathogenesis of several disease states. The eosinophilia-myalgia syndrome is a recently described entity attributed to the ingestion of the normal dietary amino acid L-tryptophan. We describe a patient who fulfills criteria for the eosinophilia-myalgia syndrome and who was ingesting supplemental L-tryptophan. Exhaustive investigations failed to reveal other causes for her eosinophilia or her myalgic/neuropathic complaints, and she improved dramatically when she discontinued the L-tryptophan supplements. The mechanisms whereby this chemical may induce this syndrome are discussed. 

Category: general pathological conditions