shukoor65/lab-rag-model huggingface dataset:
Postischemic myocardial "stunning". Identification of major differences between the open-chest and the conscious dog and evaluation of the oxygen radical hypothesis in the conscious dog. Recent studies suggest that oxygen-derived free radicals contribute to the pathogenesis of postischemic myocardial dysfunction (myocardial "stunning"). This concept, however, is predicated exclusively on results obtained in open-chest preparations, which are subject to the confounding influence of many unphysiological conditions. The lack of supporting evidence in more physiological animal models represents a major persisting limitation of the oxy-radical hypothesis of myocardial stunning. The goal of this study was to address two fundamental (and related) questions: 1) Does the open-chest animal model alter the phenomenon of myocardial stunning? 2) If so, how valid are the concepts, derived from such a model, regarding the pathogenetic role of oxy-radicals? In part 1 of the study, myocardial stunning after a 15-minute coronary occlusion was compared in 30 pentobarbital-anesthetized open-chest dogs and in 19 conscious dogs. For any given level of collateral flow during occlusion, the recovery of systolic wall thickening after reperfusion was markedly less in open-chest animals. In an additional group of five open-chest dogs, a close inverse relation was noted between body temperature and postischemic wall thickening, indicating that the recovery of the stunned myocardium in acute experiments may vary markedly depending on how temperature is controlled. Because of these major differences between open-chest and conscious dogs, the oxy-radical hypothesis needs to be tested in the latter model. Thus, in part 2 of the study, conscious unsedated dogs undergoing a 15-minute coronary occlusion were randomized to an intravenous infusion of either saline (19 coronary occlusions) or superoxide dismutase (SOD) plus catalase (CAT) (21 coronary occlusions). Despite the fact that the plasma levels of SOD and CAT declined rapidly after reperfusion, postischemic wall thickening was significantly greater in treated compared with control dogs throughout the first 6 hours of reflow. Thus, a brief (60-minute) infusion of SOD and CAT produced a sustained improvement of recovery of contractility. The magnitude of this beneficial effect was a function of the severity of ischemia: the lower the collateral perfusion, the greater the improvement effected by the enzymes. The accelerated recovery produced by SOD and CAT was not followed by any deterioration of contractility, suggesting that postischemic dysfunction is not a teleologically "protective" phenomenon. In conclusion, the severity of myocardial stunning is greatly exaggerated by the unphysiological conditions present in the barbiturate-anesthetized open-chest dog.(ABSTRACT TRUNCATED AT 400 WORDS).
Suppressor T-cell deficiency in primary sclerosing cholangitis. Case and family study. Primary sclerosing cholangitis is considered to be an autoimmune disease of the liver in which there is an association with the HLA phenotypes B8 and DR3 and in which circulating autoantibodies occur. Abnormalities of immune regulation may be present but whether or not they are primary or acquired is not known. This report is of a patient with primary sclerosing cholangitis who was homozygous for HLA B8 DR3, had a circulating antinuclear antibody, and a defect in nonspecific suppressor T-cell activity despite glucocorticosteroid treatment. Nevertheless, family studies revealed no evidence of an immunoregulatory defect in first-degree relatives despite the presence of Raynaud's phenomenon and malignancy in two sisters.
Chondroblastomalike extraskeletal chondroma. An unusual extraskeletal tumor occurring in the right thumb of a 44-year-old man exhibited histologically a chondroblastomalike appearance. The tumor was characterized by dense proliferation of chondroblastic cells admixed with a few multinucleated giant cells of osteoclast type. The patient had no evidence of local recurrence or metastasis three-and-a-half years after a simple excision.
Novel approach to iatrogenic bile peritonitis. Bile peritonitis after injury to the biliary tree is a serious complication that requires exploratory laparotomy. Our patient had an obstructing ampullary carcinoma, and generalized bile peritonitis developed from attempted percutaneous transhepatic cholangiography. The patient's condition was managed by peritoneal lavage and endoscopic transampullary stenting, with immediate relief of pain and toxicity. Exploratory laparotomy was avoided, and an eventual pylorus-sparing Whipple resection was the definitive treatment. We believe this to be the first report of successful nonoperative treatment of a patient with bile peritonitis with obstructive jaundice.
Prognostic value of galactose elimination capacity, aminopyrine breath test, and ICG clearance in patients with cirrhosis. Comparison with the Pugh score. Seventy-eight patients with cirrhosis were prospectively followed for up to 20 months, on the average. At entry into the study, galactose elimination capacity, aminopyrine breath test, and ICG clearance were measured. At the end of the study, 27 patients had died. Univariate analysis using the Kaplan-Meier method showed that both quantitative liver function tests (galactose elimination capacity: P less than 0.025; aminopyrine breath test: P less than 0.001; ICG clearance: P less than 0.005) and common clinical and biochemical data (encephalopathy: P less than 0.001; ascites: P less than 0.001; serum bilirubin: P less than 0.005; serum albumin: P less than 0.001; prothrombin index: P less than 0.05) were significant predictors of survival. To investigate whether quantitative liver function tests could contribute to a better definition of the prognosis, once Pugh score had already been taken into account, a multiple regression analysis according to the Cox model was performed. Pugh score and galactose elimination capacity resulted in the only independent prognostic covariates. From them a prognostic index was calculated, and the model was validated in an additional sample of 70 patients investigated according to the same protocol. The contribution GEC gave to the assessment of overall prognosis over that obtained using the Pugh score was slight, as estimated by the statistical parameters of the Cox's model, but was significant as assessed by a ROC curve analysis (P = 0.05). These data show that all quantitative liver function tests were predictors of survival in cirrhosis, and that the galactose elimination capacity added some new prognostic information to those already available using the Child-Turcotte-Pugh classification.
Regional differences in elastic recoil after percutaneous transluminal coronary angioplasty: a quantitative angiographic study. The immediate result of percutaneous transluminal coronary angioplasty is influenced by both plastic and elastic changes of the vessel wall. To evaluate the amount of elastic recoil after coronary balloon angioplasty, the minimal luminal cross-sectional area of the largest balloon used at highest inflation pressure was compared with the minimal luminal vessel cross-sectional area directly after final balloon deflation in 607 lesions (526 patients). Elastic recoil was defined as the difference between balloon cross-sectional area and minimal luminal cross-sectional area of the dilated coronary segment immediately after balloon withdrawal. A videodensitometric analysis technique was used to avoid geometric assumptions on stenosis morphology directly after angioplasty. Mean balloon cross-sectional area was 5.3 +/- 1.6 mm2 and minimal luminal cross-sectional area after angioplasty was 2.8 +/- 1.4 mm2. Reference areas before and after angioplasty did not differ (6.0 +/- 2.6 and 6.2 +/- 2.6 mm2, respectively). Univariate analysis revealed that asymmetric lesions, lesions located in less angulated parts of the artery and lesions with a low plaque content showed more elastic recoil. Lesions located in distal parts of the coronary tree were also associated with more elastic recoil probably related to relative balloon oversizing in these distal lesions.
Differentiation in B-precursor acute lymphoblastic leukemia cell populations with CD34-positive subpopulations. B-precursor acute lymphoblastic leukemia bone marrow specimens that contained subpopulations of cells with immunophenotypes corresponding to early (CD34) and late (CD20) and (CD22) stages of normal B-cell differentiation were studied. Subpopulations of cells were isolated according to immunophenotype and then analyzed by both a clonogenic assay and molecular genetic methods. Clonal equivalence of the early and late immunophenotypic subpopulations was confirmed for each case by the demonstration of identical lg gene rearrangements. The in vitro colony-forming assay consistently showed a growth advantage for the CD34+ subpopulations over the CD34- subpopulations. CD34 mRNA was detected readily in these isolated precursor cells. When two specimens in which virtually all of the leukemia cells were CD34+ and CD34+CD20+ and CD34+CD22+ subpopulations were also present the CD34 mRNA was limited to the cells without the late-stage differentiation antigens on their surface. Furthermore, the c-myb mRNA was found only in the subpopulations that also contained CD34 mRNA. Our results show that a limited program of differentiation reminiscent of normal B-cell development may be present in this leukemia.
Global T wave inversion. Because global T wave inversion has not been specifically characterized, 100 electrocardiograms (ECGs) with this pattern (frontal plane T vector -100 degrees to -170 degrees with precordial T inversion) were prospectively collected from approximately 30,000 consecutively interpreted ECGs and analyzed blindly. There was a striking female predominance (82 women vs. 18 men; p less than 0.0005) despite an essentially equal number of female and male hospital admissions. There was a single statistically significant ECG correlate: a more vertical QRS axis in women (+14.1 degrees +/- 45.3 degrees vs. -5.6 degrees +/- 31.3 degrees; p = 0.034). The T waves were basically symmetric (68%), the influence of this factor usually altering the characteristically asymmetric T wave inversions of right bundle branch block (4 of 5) and left ventricular hypertrophy (21 of 36). Asymmetry was mainly associated with digoxin therapy (21 of 32 patients taking digoxin; p less than or equal to 0.0005) and a corrected QT (QTc) interval (0.433 +/- 0.095) shorter than with symmetric T wave inversions (0.507 +/- 0.074; p less than or equal to 0.0005) though not reaching the degree of shortening expected for digitalization. Twenty-eight patients admitted for acute myocardial infarction and 23 for a central nervous system disorder accounted for the majority of patients with symmetric T wave inversion. Fifteen of 18 patients who had coronary angiography had some degree of coronary artery disease: 3 had angiographically normal coronary arteries.
Somato-somatic referred pain caused by suprasegmental spinal cord tumor. Tactile stimulation of a coin-sized area in a T-2 dermatome consistently triggered a lancinating pain in the ipsilateral C-8 dermatome in a 38-year-old woman. The SEP and an MRI led to a diagnosis of a tumor at the left cervico-medullary junction, much higher than the clinically suspected level. Surgical exploration revealed an exophytic glioma, and the pain was abolished postoperatively. Ephaptic transmission at the tumor site was suspected as a pathophysiologic mechanism.
Early constrictive pericarditis and anemia after Dressler's syndrome and inferior wall myocardial infarction. Early constrictive pericarditis and anaemia developed in a 52 year old man after he had an inferior wall myocardial infarction complicated by Dressler's syndrome. Total pericardiectomy at the time of coronary artery bypass surgery resulted in complete resolution of signs and symptoms.
Effect of sinorphan, an enkephalinase inhibitor, on plasma atrial natriuretic factor and sodium urinary excretion in cirrhotic patients with ascites. We examined the acute effects of sinorphan, an inhibitor of enkephalinase, on plasma atrial natriuretic factor (ANF) and urinary sodium excretion in cirrhotic patients with ascites. A single oral dose of sinorphan (100 or 30 mg in 11 and 5 patients, respectively) was administered against placebo according to a double blind cross-over protocol. Basal plasma ANF levels varied over a large range between 2.6-79 pmol/L. Sinorphan, at a dose of 100 mg, inhibited 70% of plasma enkephalinase activity 60 min after ingestion and elicited simultaneously an increase in plasma ANF and cGMP levels 1.8 and 1.5 times basal values, respectively. There was a transient increase in sodium urinary output without a change in creatinine clearance over the initial 2-h period following drug administration. An increase in urinary cGMP was also observed on a longer period of 6 h. Plasma aldosterone decreased significantly, but the lowest concentration was reached 1 h later than the peak of plasma ANF. Mean blood pressure and PRA were unmodified. The effects of 30 mg sinorphan on plasma ANF, cGMP, and aldosterone were also significant, but less marked than those of the higher dose. Therefore, enkephalinase inhibition transiently increases sodium urinary excretion in cirrhotic patients with ascites via a mechanism that is likely to imply reduction of ANF catabolism. These results suggest that ANF could play a role in the control of sodium homeostasis in liver cirrhosis with ascites.
Aneurysm of the distal anterior inferior cerebellar artery unrelated to the cerebellopontine angle: case report. This is a case report of an unusual aneurysm of the distal anterior inferior cerebellar artery. A 44-year-old woman had a severe frontal headache and vomiting of sudden onset. On the day after admission, the patient began to demonstrate nuchal rigidity and difficulty with upward gaze bilaterally. There were no complaints at this time suggestive of a syndrome of the cerebellopontine angle. A computed tomographic scan revealed an intraventricular hemorrhage of the 3rd and 4th ventricles; however, multiple attempts at four-vessel angiography were required before an aneurysm could be demonstrated. On the 28th hospital day, a suboccipital craniectomy using the retromastoid approach in the lateral position was performed. A saccular aneurysm with a surrounding hematoma in the distal anterior inferior cerebellar artery was found and clipped. The operative findings revealed that the aneurysm was unrelated to the cerebellopontine angle. After surgery, the patient had an uneventful recovery and complete resolution of symptoms.
Cancer incidence in Norwegian Seventh-Day Adventists 1961 to 1986. Is the cancer-life-style association overestimated? Standardized incidence ratio for cancer in Norwegian Seventh-Day Adventists compared with the general population was not significantly different from unity (men 91, women 97). Persons converting late in life had a higher incidence than those converting at an earlier age. Respiratory cancers (standardized incidence ratio [SIR] 59, 95% CI = 36 to 91) and cancers with an unspecified site (SIR 53, 95% CI = 25 to 97) were rarer and cancer of the uterine corpus (SIR 164, 95% CI = 109 to 237) was more common in Seventh-Day Adventists before the age of 75 years. Inclusion of all registered Seventh-Day Adventists regardless of religious activity and the relatively low cancer incidence rates in the Norwegian population could contribute to the nonsignificant result with regard to total cancer. Main etiologic factors in cancer development in Norway should be sought in areas where Seventh-Day Adventists do not differ from the general population.
Epileptogenic effect of hypoxia in the immature rodent brain. The response to cerebral hypoxia/ischemia may be different in the neonate compared to other age groups. An in vivo model was developed in the rat to determine whether there are age-dependent differences in the effects of hypoxia on electroencephalographic (EEG) activity. EEG recordings were obtained from Long Evans hooded rats deprived of oxygen at five ages: postnatal days 5 to 7, 10 to 12, 15 to 17, 25 to 27, and 50 to 60. Oxygen concentration was varied from 0, 2, 3, and 4% between animals. EEGs were recorded in all animals before, during, and at 1 hour after exposure to the hypoxic condition and at 1 to 7 days afterward in a subset of animals. All animals were deprived of oxygen until the onset of apnea and bradycardia to 20 to 40% of baseline heart rate values. Hypoxia resulted in isoelectric EEG significantly more frequently in the animals deprived of oxygen at postnatal days 25 to 27 and 50 to 60 than in the younger age groups. A highly significant effect was that the animals deprived at postnatal days 5 to 17 revealed a high incidence of epileptiform EEG activity during hypoxia. In contrast, the older animals exhibited only rare isolated EEG spikes before reaching an isoelectric EEG. The severity of hypoxia-induced epileptiform EEG changes was highest in the animals subjected to moderately hypoxic conditions (3% and 4% oxygen) at postnatal days 10 to 12. Furthermore, epileptiform changes persisted for hours to days following prolonged episodes of hypoxia in the younger animals. This study demonstrates a unique response of the immature brain to exhibit epileptiform activity during hypoxia.
Childhood cancer among the Polynesian population. From June 1981 through June 1989, 95 Polynesian children were seen for initial care of malignancy at the Princess Mary Hospital for Children (PMHC). The incidence of malignancy in the Polynesian populations served, the histology of the malignancies, and the outcome of therapy were reviewed and compared with 185 non-Polynesian (non-P) patients seen during the same period. Incidence figures for Polynesians and non-P were similar, but histologic patterns differed, showing an increased occurrence of leukemia, particularly nonlymphoblastic leukemia, an increased occurrence of bone tumors, and a decreased incidence of central nervous system tumors for Polynesians. Survival for Polynesian children with acute lymphoblastic leukemia was worse than for non-P. Survival in all other disease categories was similar.
Hemorrhagic events during therapy with recombinant tissue-type plasminogen activator, heparin, and aspirin for acute myocardial infarction. Results of the Thrombolysis in Myocardial Infarction (TIMI), Phase II Trial. OBJECTIVES: To assess the effects of invasive procedures, hemostatic and clinical variables, the timing of beta-blocker therapy, and the doses of recombinant plasminogen activator (rt-PA) on hemorrhagic events. DESIGN: A multicenter, randomized, controlled trial. SETTING: Hospitals participating in the Thrombolysis in Myocardial Infarction, Phase II trial (TIMI II). INTERVENTIONS: Patients received rt-PA, heparin, and aspirin. The total dose of rt-PA was 150 mg for the first 520 patients and 100 mg for the remaining 2819 patients. Patients were randomly assigned to an invasive strategy (coronary arteriography with percutaneous angioplasty [if feasible] done routinely 18 to 48 hours after the start of thrombolytic therapy) or to a conservative strategy (coronary arteriography done for recurrent spontaneous or exercise-induced ischemia). Eligible patients were also randomly assigned to either immediate intravenous or deferred beta-blocker therapy. MEASUREMENTS: Patients were monitored for hemorrhagic events during hospitalization. MAIN RESULTS: In patients on the 100-mg rt-PA regimen, major and minor hemorrhagic events were more common among those assigned to the invasive than among those assigned to the conservative strategy (18.5% versus 12.8%, P less than 0.001). Major or minor hemorrhagic events were associated with the extent of fibrinogen breakdown, peak rt-PA levels, thrombocytopenia, prolongation of the activated partial thromboplastin time (APTT) to more than 90 seconds, weight of 70 kg or less, female gender, and physical signs of cardiac decompensation. Immediate intravenous beta-blocker therapy had no important effect on hemorrhagic events when compared with delayed beta-blocker therapy. Intracranial hemorrhages were more frequent among patients treated with the 150-mg rt-PA dose than with the 100-mg rt-PA dose (2.1% versus 0.5%, P less than 0.001). The extent of the plasmin-mediated hemostatic defect was also greater in patients receiving the 150-mg dose. CONCLUSIONS: Increased morbidity due to hemorrhagic complications is associated with an invasive management strategy in patients with acute myocardial infarction. Our findings show the complex interaction of several factors in the occurrence of hemorrhagic events during thrombolytic therapy.
Treatment of unresectable meningiomas with the antiprogesterone agent mifepristone. The possibility that meningioma growth may be related to female sex hormone levels is suggested by several lines of evidence. Meningiomas are twice as common in women as in men, have been observed to wax and wane with pregnancy, and are positively associated with breast cancer. A physiological explanation for these phenomena is provided by the finding of steroid hormone receptors in meningiomas. However, unlike breast cancer, meningiomas are much more commonly positive for progesterone receptors than for estrogen receptors. The authors initiated a study on long-term oral therapy of unresectable meningiomas with the antiprogesterone mifepristone (RU486). Fourteen patients received mifepristone in daily doses of 200 mg for periods ranging from 2 to 31+ months (greater than or equal to 6 months in 12 patients). Five patients have shown signs of objective response (reduced tumor measurement on computerized tomography scan or magnetic resonance image, or improved visual field examination). Three have also experienced subjective improvement (improved extraocular muscle function or relief from headache). The side effects of long-term mifepristone therapy have been mild. Fatigue was noted in 11 of the 14 patients. Other side effects included hot flashes in five patients, gynecomastia in three, partial alopecia in two, and cessation of menses in two. Long-term therapy with mifepristone is a new therapeutic option that may have efficacy in cases of unresectable benign meningioma.
Transscleral leiomyoma. A bluish-pink epibulbar lesion, which slowly enlarged over a period of 5 years, developed in a 31-year-old woman. The lesion initially resembled a staphyloma, based on the very thinned overlying sclera, but subsequent evaluation suggested that it was a solid mass. At the time of surgical removal, the mass appeared to have originated in the supraciliary region and to have eroded outward through the sclera. Histopathologically, the mass proved to be a leiomyoma. The authors propose theoretic possibilities to explain the location of this rare type of ocular smooth muscle tumor.
Detection of intraoperative laser injury to the facial nerve by electromyographic monitoring of facial muscles. Injury to the facial nerve is a significant risk during resection of cerebellopontine angle tumors. To minimize the risk of facial nerve injury, intraoperative electromyographic monitoring of facial musculature is frequently used. However, the reliability of such monitoring systems for detection of thermal nerve injury resulting from the use of carbon dioxide lasers has not been systematically evaluated. We determined the sensitivity of a computerized electromyographic monitor for detection of laser facial nerve injury in an anesthetized rat model. The mandibular and buccal branches of the facial nerve were isolated in 12 rats. A carbon dioxide laser was used to create controlled sites of thermal injury to both nerves over a 3-hour period. When a laser injury was created distal to previous injury sites, electromyographic discharge was noted in 72% to 82% of injuries. Laser injury proximal to previous injury sites was detected with 33% efficiency. These detection rates did not change significantly over a 3-hour period. This preliminary data suggests that electromyographic monitoring of facial musculature allows detection of facial nerve injury caused by carbon dioxide lasers.