shukoor65/lab-rag-model huggingface dataset:
Subcellular characteristics of phospholipase A2 activity in the rat kidney. Enhanced cytosolic, mitochondrial, and microsomal phospholipase A2 enzymatic activity after renal ischemia and reperfusion. Phospholipase A2 (PLA2) activities in cytosolic, mitochondrial, and microsomal fractions of rat kidneys were characterized under control conditions, after ischemia, and subsequent to ischemia and reperfusion. Two forms of PLA2 activity were present in the cytosolic fraction: a high molecular weight form, active against phosphatidylcholine (PC), and phosphatidylethanolamine (PE), which upon purification has a molecular mass of 110 kD; and smaller form (Mr approximately 14 kD), active against PE. In mitochondrial and microsomal fractions a single form (Mr approximately 14 kD), active against both PC and PE, was dominant. Activities in each fraction were optimal at pH 8.5-9.5. Cytosolic PLA2 activity was enhanced when Ca2+ concentration [( Ca2+]) was increased over the range of 10(-7) to 10(-6) M. Mitochondrial PLA2 activity required higher [Ca2+] for activation (greater than 10(-6) M). After 45 min of ischemia cytosolic PLA2 activity was decreased, whereas mitochondrial and microsomal activities were increased. When ischemia was followed by 1 h of reperfusion, cytosolic, mitochondrial, and microsomal activities were enhanced. Ischemia alone did not change the gel filtration chromatography patterns of PLA2 activity, but ischemia and reperfusion resulted in the appearance of a new peak of activity in cytosolic and mitochondrial fractions (Mr approximately 2-3 kD). Thus, the rat kidney has multiple forms of PLA2 activity, likely representing distinct enzymes, with Ca2+ dependencies suggesting regulation by Ca2+ in vivo. Ischemia and reperfusion result in stable increases of PLA2 activity in each subcellular fraction, perhaps related to covalent modifications of PLA2's, which likely account for membrane phospholipid degradation, and increased tissue levels of unsaturated free fatty acids.
Polytetrafluoroethylene vs. polypropylene suture for endoscopic bladder neck suspension. Between May 1989 and October 1989, 24 women underwent a prospective, randomized study comparing polypropylene (Prolene) and polytetrafluoroethylene (Gore-Tex) sutures for endoscopic bladder neck suspension. Polypropylene was associated with significantly more suture pain than polytetrafluoroethylene. Polytetrafluoroethylene was more difficult to tie at a predetermined tension.
Diltiazem administration after crystalloid resuscitation restores active hepatocellular function and hepatic blood flow after severe hemorrhagic shock. Studies have shown that active hepatocellular function is depressed after hemorrhagic shock, despite crystalloid resuscitation. It is also known that calcium antagonists produce various beneficial effects on cell and organ function after ischemia and shock. However, it remains unknown whether such agents have any salutary effects on the depressed active hepatocellular function and hepatic blood flow in a nonheparinized model of trauma and hemorrhage. To study this, rats underwent a midline laparotomy (trauma-induced) and were bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum bleedout was returned in the form of Ringer's lactate. They were then resuscitated with four times the volume of shed blood with Ringer's lactate over 60 minutes, during and after which diltiazem (400 micrograms/kg body weight) was infused intravenously over 95 minutes. Active hepatocellular function (Vmax and Km) was determined with an in vivo indocyanine green clearance technique. Effective hepatic blood flow (EHBF) was determined by Fick principle and corrected by the indocyanine green extraction ratio. Hepatic microvascular blood flow (HMBF) was measured by laser Doppler flowmetry. Results indicate that Vmax, Km, EHBF, and HMBF decreased significantly at 1.5 and 4 hours after resuscitation. Diltiazem infusion restored the depressed Vmax, Km, EHBF, and HMBF and prevented the occurrence of hepatic edema. Thus, diltiazem may be a useful adjunct in the treatment of trauma and severe hemorrhage even in the absence of blood resuscitation.
Bradykinin-stimulated inositol phosphate production in NG108-15 cells is mediated by a small population of binding sites which rapidly desensitize. [3H]Bradykinin (BDK) binds to two distinct binding sites (P less than .01, N = 12) in NG108-15 cell membranes; (site 1: Kd1 = 3.09 x 10(-10) M, Bmax1 = 242 +/- 24 fmol/mg protein) and (site 2: Kd2 = 1.94 x 10(-8) M, Bmax2 = 491 +/- 75 fmol/mg protein). Although site 1 comprises only 33 +/- 4% (N = 12) of the total binding site population, comparison of the binding affinity and functional potency for BDK agonist analogs exhibiting differential selectivity for the two sites reveals that this high affinity site is the receptor mediating inositol monophosphate (IP) production in this cell line. BDK-stimulated IP production undergoes a very rapid (5 min) desensitization that is characterized by both a loss in agonist potency (EC50 = 3.57 x 10(-9) M vs. 1.94 x 10(-10) M in controls; P less than .001, N = 12) and a decrease in amplitude of response (fold stimulation = 1.45 +/- 0.06 vs. 1.80 +/- 0.09 in controls; P less than .01, N = 12). Only the decrease in response amplitude is attenuated by down-regulation of protein kinase C by prior long term treatment of the cells with 12-O-tetradecanoylphorbol 13-acetate (TPA), indicating an involvement of protein kinase C activation in the desensitization process. Desensitization is accompanied by down-regulation of site 1 only (Bmax1 = 71 +/- 8 fmol/mg (N = 10; P less than .001 vs. controls)); Bmax2 and the Kd for BDK at both sites remain unchanged, further supporting the contention that site 1 is the functionally relevant receptor. In contrast to the functional data, long term TPA treatment does not attenuate the receptor down-regulation, indicating that the rapid desensitization involves both receptor-related and postreceptor mechanisms. The implications of this property of the BDK receptor for analog design and receptor classification are discussed.
Effects of vascular runoff on myointimal hyperplasia after mechanical balloon or thermal laser arterial injury in dogs. BACKGROUND. Clinical evidence suggests that poor vascular runoff reduces the long-term success rate of femoral angioplasty procedures. The purpose of this experimental study was to examine myointimal hyperplasia of dog femoral arteries after balloon denudation, thermal laser arterial injury, or sham operation in normal and reduced vascular runoff conditions. METHODS AND RESULTS. Before mechanical balloon injury or transluminal heated laser probe motion, the peripheral vascular runoff of dogs was reduced by ligating the femoral artery below its three distal side branches, decreasing the femoral flow rate from 114 +/- 9 to 52 +/- 5 ml/min (mean +/- SEM). Endothelial denudation with a predominantly intact elastic internal membrane and circumferential structural changes in the media were noted by light microscopy 1 hour after balloon injury. Focal completely necrotic lesions of intima and media were found 1 hour after thermal laser arterial injury. After 8 weeks, the maximal thickness of neointima plus media of the site of previous intervention was greater after balloon injury (0.45 +/- 0.03 mm) and thermal laser injury (0.54 +/- 0.03 mm) than after sham operation (0.40 +/- 0.01 mm; p less than 0.001) in normal runoff dogs. Reduced vascular runoff augmented myointimal hyperplasia both in the balloon-injured and thermally damaged arteries; the wall thickness increased from 0.45 +/- 0.03 to 0.93 +/- 0.10 mm and from 0.54 +/- 0.03 to 0.65 +/- 0.05 mm, respectively (p less than 0.001). The neointimal and medial wall area of the balloon-injured arteries contributed 48% to the area encompassed by the external elastic membrane compared with an 81% portion when vascular runoff was reduced (p less than 0.01). A 47% neointimal and medial wall area was found in thermally injured arteries with normal runoff compared with 63% after runoff reduction (p less than 0.05). CONCLUSION. This study suggests that hemodynamic factors associated with poor vascular runoff play an important role in extending myointimal hyperplasia independent of method and severity of the arterial injury during angioplasty.
Human papillomavirus--associated vulvar verrucous carcinoma in a 20-year-old with an intact hymen. A case report. A 20-year-old woman with vulvar verrucous carcinoma, the youngest such patient reported to date, had human papillomavirus DNA 6/11 identified with an in situ hybridization technique. In addition to her youth, the patient was unusual in that she had an intact hymen. Although she denied having engaged in sexual activity, venereal transmission of the virus may have occurred without vaginal penetration.
Carotid endarterectomy in Great Britain and Ireland: trends and current practice. Of 309 questionnaires on carotid endarterectomy sent to all surgeons in Great Britain and Ireland who might use this technique, 298 (96 per cent) were returned. In all, 110 (37 per cent) of 298 surgeons performed at least one carotid endarterectomy in 1989; 67 performed less than 10 and 43 greater than 10. In total, these 110 surgeons performed 1417 operations in 1989, a situation that has changed little over 5 years since the previous survey. Transient ischaemic attack and minor stroke remain the main indications for carotid endarterectomy; the operation was hardly ever performed for asymptomatic stenosis. By 1989 almost all surgeons initially assessed prospective patients using a technique less invasive than conventional angiography; duplex scanning was used 'always' or 'sometimes' by 70 per cent of surgeons. While 72 per cent of surgeons in 1984 'always' required conventional angiograms before operation, by 1989 only 21 per cent did so, most now relying on less invasive techniques. During operation there was an increasing use of shunts, carotid sinus nerve blockade and patch closure of the arteriotomy. The overall number of carotid endarterectomies performed annually in Great Britain and Ireland has remained steady over the past 5 years and is relatively low for a population of 60 millions. An increase in the number of surgeons performing the operation is almost entirely accounted for by an increase in those performing less than 10 carotid endarterectomies per year.
Transplantation of kidneys from pediatric cadaver donors to adult recipients. Pediatric donors (less than 12 years old) are a potentially important source of kidneys for adult recipients. Previous reports of decreased graft survival and increased complication rates have made surgeons wary of using such kidneys. In 64 kidneys from younger donors transplanted to adult recipients the delayed graft function rate (41 versus 42%), and 2 and 3-year graft survival rates (67 versus 72% and 61 versus 65%, respectively) were similar to those seen with kidneys from adult donors. Kidneys from donors 24 months old or less experienced an 80% rate of graft loss at 1 year. When these kidneys are excluded the 1-year graft survival rate was similar to kidneys from older and younger donors (70 versus 77%). Mean serum creatinine at 1 year was similar in both groups (155 +/- 21 versus 151 +/- 10). Pediatric kidneys except those obtained from donors 2 years old or less are suitable for adult recipients. However, kidneys from very young donors may be more appropriate to pediatric recipients.
Use of social science research to improve epidemiologic studies of and interventions for diarrhea and dysentery. The significance of dysentery has not been recognized in community-based programs for the management of diarrhea. Culturally sensitive methods of classification and algorithms for treatment of these diseases must be developed. Considered in this article is the manner in which ethnographic studies of diarrhea can contribute to descriptive epidemiologic data on diarrhea and dysentery and to procedures of health education and evaluation of interventions for the diseases. Indigenous terms for bloody diarrhea exist in many cultures. Local use of such terms must be carefully examined before they are incorporated in health education efforts and epidemiologic surveillance programs.
Activation of a member of the steroid hormone receptor superfamily by peroxisome proliferators We have cloned a member of the steroid hormone receptor superfamily of ligand-activated transcription factors. The receptor homologue is activated by a diverse class of rodent hepatocarcinogens that causes proliferation of peroxisomes. Identification of a peroxisome proliferator-activated receptor should help elucidate the mechanism of the hypolipidaemic effect of these hepatocarcinogens and aid evaluation of their potential carcinogenic risk to man.
Experimental evaluation of myocardial protective effect of prostacyclin analog (OP-41483) as an adjunct to cardioplegic solution. A stable prostacyclin analog (OP-41483) was evaluated for myocardial protective effect against global ischemia with the use of cardioplegia. Isolated canine hearts (n = 25) were exposed to 60 minutes of warm (37 degrees C) global ischemia after the arrest by crystalloid cardioplegia. Prostaglandin analog was given in three different ways: preadministration (700 ng/kg body weight per minute) before ischemia for 30 minutes (group I, n = 5), given as a component of cardioplegic solution (600 ng/ml, group II, n, = 6), and post-administration (25 ng/kg body weight per minute) during reperfusion for 30 minutes (group III, n = 7). During reperfusion, coronary sinus blood flow, 6-keto-prostaglandin F1 alpha in coronary sinus blood, and myocardial oxygen consumption were measured during reperfusion. As a result, groups II and III showed significantly better global left ventricular function (developed pressure, maximum dP/dt, and diastolic compliance) than the control group (without prostaglandin analog, n = 7) and group I. Myocardial oxygen consumption at reperfusion (1 minute) was significantly larger in group II than in the control group. 6-keto-prostaglandin F1 alpha flux was significantly larger in group II than in the other three groups during reperfusion. The results indicated that prostaglandin analog has a beneficial effect on myocardial protection under global ischemia with cardioplegia, particularly when used as a component of cardioplegic solution and also during reperfusion. The mechanism may relate to the cytoprotective effect (including protection of endothelium with enhanced endogenous prostacyclin production at reperfusion and also to the modulation of reperfusion per se.
Cortical control of reflexive visually-guided saccades. Reflexive visually-guided saccade triggering may be facilitated or inhibited by the cerebral cortex. To study this control, saccades made towards suddenly appearing visual targets (saccade task) or away from them (antisaccade task) were recorded electro-oculographically in 45 patients with limited unilateral cerebral infarction. Lesions affected (1) the superior part of the angular gyrus (area 39 of Brodmann) in the posterior parietal cortex (PPC), (2) the dorsolateral prefrontal cortex (PFC) (area 46 of Brodmann), (3) the frontal eye field (FEF), or (4) the supplementary motor area (SMA). As these 4 types of lesions were located either in the right or the left cerebral hemisphere, patients were divided into 8 groups. Saccade latency, in the saccade task, and the percentage of errors (misdirected saccades made towards the visual target), in the antisaccade task, were compared in each group of patients with the values of 20 control subjects. In the saccade task, saccade latency was significantly increased bilaterally in the right PPC group. In the left PPC group, the increase in latency was less marked, and significant only for saccades made contralaterally to the lesion. In the different frontal groups, latency was unchanged or only slightly increased. These results confirm that the main area facilitating the triggering of reflexive visually-guided saccades is located in the PPC, in or near the superior part of the angular gyrus. The difference between right and left parietal lesions could be due to the predominance of the right hemisphere in the control of these saccades. In the antisaccade task, the percentage of errors was significantly increased bilaterally in both PFC groups compared with the control group and also to the FEF and SMA groups. These results suggest that the PFC is the main area in the cerebral hemisphere inhibiting reflexive visually-guided saccades.
HBxAg in the liver from carrier patients with chronic hepatitis and cirrhosis. Formalin-fixed, paraffin-embedded specimens from 110 cases of chronic hepatitis and 108 cases of cirrhosis were stained for HBxAg by the avidin-biotin complex technique using specific antisera made against full-length HBxAg polypeptide or derived synthetic peptides. These tissues were also stained for the HBsAg and HBcAg by the peroxidase-anti-peroxidase method. Among patients with chronic hepatitis, 86% were HBsAg positive in liver cells, 60% were surface antigen positive and 32% were core antigen positive. Among patients with cirrhosis, 97% were HBsAg positive in liver cells, 72% were surface antigen positive and 17% were positive for core antigen. Staining specificity was demonstrated, in part, by using preimmune sera in the place of primary antibody, by blocking of the primary antibody with the appropriate antigen before assay and by testing uninfected liver controls. The persistence and high frequency of HBxAg in liver cells from patients with chronic liver disease suggest that it may play one or more important roles in the pathogenesis of chronic infection. It is possible that detection of HBxAg in the liver could be an additional new diagnostic marker for hepatitis B virus infection. However, the function(s) of HBxAg in the pathogenesis of the chronic liver disease, if any, remains to be explained.
Pyomyositis in patients with the human immunodeficiency virus: an unusual form of disseminated bacterial infection. PURPOSE AND PATIENTS: Pyomyositis, a common disease in the tropics, is rare in the continental United States, with approximately 83 cases described in the literature in the past two decades. The occurrence of pyomyositis complicating human immunodeficiency virus (HIV) infection has been reported in 10 patients since 1986. We report six cases of this entity in patients with advanced HIV disease seen in our institution over a 20-month period. A common denominator in all of our patients was muscle injury, induced by either exercise or trauma. Unlike most previous reports of HIV-associated pyomyositis, the clinical picture in our cases was complicated by the development of abscesses in multiple muscle groups, requiring prolonged antimicrobial therapy and repeated drainage procedures for successful management. Interestingly, one patient developed concomitant rhabdomyolysis--an otherwise rare event in classical pyomyositis. Staphylococcus aureus was the predominant infecting organism in this as well as all other series. Of note, we also observed and report the first case, to our knowledge, of gram-negative pyomyositis in an HIV-infected individual. The pathogenic implications of this catalase-producing gram-negative isolate are discussed in the context of neutrophil abnormalities in HIV disease. CONCLUSION: Like tropical pyomyositis, its HIV-associated counterpart appears to be multifactorial in origin. Its recent recognition suggests that, in addition to underlying abnormalities of host defense, factors relating to the prolonged survival of patients with late-stage disease, including myopathy, might play an important contributory role.
Verapamil and migraine prophylaxis: mechanisms and efficacy. Calcium channel blockers have demonstrated efficacy in investigative use for prophylaxis of migraine and cluster headaches. In particular, verapamil, with its low side-effect profile, appears to be a promising alternative to the currently available agents for prophylactic treatment of chronic recurring headaches. Although its exact mechanisms of action in this application are unknown, verapamil exerts a vasodilatory effect on cerebral arteries and interacts with serotonergic systems involved in migraine pathogenesis. A review of studies from the past decade indicates that verapamil may be as effective as traditional therapies as prophylaxis for the major types of chronic recurring headache.
Pathogenesis and management of gastroesophageal reflux disease. Several pathophysiologic abnormalities known to be associated with the development of gastroesophageal reflux disease (GERD) are reviewed. Among them are the contributions of lower esophageal sphincter pressure, length, and relaxation, the role of hiatal hernia, delayed esophageal acid clearance, and impaired esophageal mucosal resistance. Gastric factors--volume, secretion, the character of the refluxant, and the rate of gastric emptying--also play a role in the pathogenesis of GERD. Treatment requires an individualized approach based on the extent of the symptoms, esophagitis, and other reflux complications. Three phases of treatment--lifestyle modifications, pharmacologic manipulation, and surgery--are discussed, as is maintenance therapy and prevention of recurrent disease.
Dobutamine versus dipyridamole echocardiography in coronary artery disease. Dobutamine and dipyridamole echocardiography are gaining popularity as exercise-independent stress tests for the diagnosis of coronary artery disease. To compare the feasibility, sensitivity, and specificity of dobutamine echocardiography to dipyridamole echocardiography, we conducted both tests, on different days and in random order, on 35 patients with chest pain and suspected coronary artery disease. Dobutamine was administered in scalar doses up to 40 micrograms/kg per minute and dipyridamole up to 0.84 mg/kg for 10 minutes. Dobutamine echocardiography testing was positive in eight of 16 (50%) patients with single-vessel disease and in 11 of 12 (92%) patients with multivessel disease, resulting in an overall sensitivity of 68% for the presence of coronary artery disease. Dipyridamole echocardiography testing showed the same sensitivity as dobutamine in patients with multivessel disease but a lower sensitivity (31%) in single-vessel disease, resulting in an overall sensitivity of 57%. The specificity of both tests was 100%. An ST segment shift of more than 1 mm compared with baseline was documented in 74% of the positive dobutamine echocardiography tests and in 81% of the positive dipyridamole echocardiography tests. No major complications occurred during both tests. Ventricular arrhythmias occurred in 11 patients with dobutamine and in none with dipyridamole (31% versus 0%, p less than 0.001). Thus, in our selected population dobutamine echocardiography testing demonstrated a similar overall sensitivity and specificity for the diagnosis of coronary artery disease compared with dipyridamole, with a slightly better sensitivity for single-vessel disease but a greater arrhythmogenic potential.