shukoor65/lab-rag-model huggingface dataset:
Post-myocardial infarction mortality in patients with ventricular premature depolarizations. Canadian Amiodarone Myocardial Infarction Arrhythmia Trial Pilot Study BACKGROUND. Among survivors of acute myocardial infarction, frequent and repetitive ventricular premature depolarizations (VPDs) detected on ambulatory monitoring contribute independently to the risk of all-cause mortality and sudden death. Apart from the beta-blockers, no antiarrhythmic drug has been reliably demonstrated to reduce mortality among patients with VPDs. A pilot study was undertaken to gather data to aid in the design of a multicenter trial of amiodarone for the reduction of mortality from cardiac arrhythmias in such patients. METHODS AND RESULTS. Seventy-seven patients with acute myocardial infarction within the previous 6-30 days and 10 or more VPDs/hr or one or more runs of ventricular tachycardia on 24-hour electrocardiographic recording were randomized in a double-blind fashion in a 2:1 amiodarone-to-placebo ratio. The loading dose was 10 mg/kg/day for 3 weeks. The maintenance dose was 300-400 mg/day with reductions at 4-month intervals in response to VPD suppression, excessive plasma levels, or toxicity. VPD suppression at 1 week and 2 weeks was 63% and 85%, respectively, on amiodarone and 17% and 27%, respectively, on placebo. Apart from thyroid-stimulating hormone elevation and skin reactions, no side effects occurred more frequently with amiodarone. The study drug was stopped for side effects or noncompliance in 35% of amiodarone patients and 34% of placebo patients. Patients were followed for a maximum of 2 years (mean, 20 months). Arrhythmic death or resuscitated ventricular fibrillation occurred in two of 48 amiodarone patients (6%) and four of 29 placebo patients (14%), whereas the rates of all-cause mortality were five of 48 (10%) and six of 29 (21%), respectively. CONCLUSIONS. Amiodarone, in moderate loading and maintenance dosages with adjustments in response to plasma levels, VPD suppression, and side effects, results in effective VPD suppression and acceptable levels of toxicity.
Prostate-type gland in the epididymis. We confirmed the presence of a prostate-type gland in the epididymis of a 30-year-old white man by immunohistochemical analysis using prostate specific antigen and prostate specific acid phosphatase. We suggest possible histogenetic mechanisms for such previously undescribed morphological heterogeneity within this wolffian duct derivative.
Proliferation index in various stages of breast cancer determined by Ki-67 immunostaining. To investigate factors involved in progression of breast cancer, we estimated the growth fraction of malignant cell populations in various stages of mammary cancer growth. Frozen sections were immunostained with the Ki-67 monoclonal antibody and the proliferation index determined using static image analysis. Pure intraductal carcinoma, intraductal carcinoma coexisting with invasive disease, and metastatic sites coexisting with primary tumors were studied. The proliferation index of pure intraductal carcinomas (mean 4.5%, median 1.8%) was not significantly different from invasive mammary cancers (mean 5.1%, median 2.2%). The proliferation index determined for the in situ component of primary cancers (mean 3.8%, median 1.5%) was not significantly different from values obtained from the invasive component of growth (mean 4.2%, median 2.1%). Variability between in situ and invasive components for individual cases was minimal in tumors whose proliferation index was less than 3.0%; for tumors with higher proliferation indices, the differences were greater. However, there was no trend toward a decrease or increase in growth fraction for the two components of primary tumor growth. The mean proliferative index for primary tumors (mean 4.9%, median 4.0%) was not significantly different from the mean proliferative score from a matched group of metastatic sites in the same patients (mean 5.7%, median 5.5%). Comparison of individual cases uncovered differences in some tumors; again no consistent trends in either direction were noted. An increase (or decrease) in growth activity does not accompany the transition from intraductal (in situ) disease to invasive mammary cancer, nor does a change in growth fraction necessarily accompany progression of mammary cancer from the primary to regional metastatic site.
Thymosin treatment of chronic hepatitis B: a placebo-controlled pilot trial Chronic hepatitis B is a severe and frequently progressive disease. We assessed the safety and efficacy of thymosin fraction 5 and thymosin-alpha 1 in a prospective, placebo-controlled trial in 12 patients with chronic hepatitis B. All patients had histological and biochemical evidence of active liver disease for at least 6 mo before treatment and were positive for serum hepatitis B virus DNA and HBsAg. Seven patients received thymosin fraction 5 or thymosin-alpha 1 and five patients received placebo twice weekly for 6 mo. By the conclusion of the study (1 yr), serum aminotransferase levels had improved significantly in thymosin-treated patients, but not in the placebo group. Six (86%) of the thymosin treated patients and one (20%) patient given placebo cleared hepatitis B virus DNA from serum (p less than 0.04, Fisher's exact test). After treatment, replicative forms of hepatitis B virus DNA were present in the liver specimens of four of five placebo-treated patients but in only one of seven thymosin-treated patients (p less than 0.04, Fisher's exact test). Response to thymosin therapy was associated with significant improvements in peripheral blood lymphocyte and CD3 and CD4 counts and in in vitro production of interferon-gamma over initial values. No significant side effects were observed in patients given thymosin or in placebo-treated patients. Clinical, biochemical and serological improvement in patients responding to thymosin were sustained during 26 +/- 3 mo of follow-up. The results of this pilot trial suggest that thymosin therapy promotes disease remission and cessation of hepatitis B virus replication in patients with chronic viral infection.
Instability of the cervical spine after decompression in patients who have Arnold-Chiari malformation. Stability of the cervical spine was studied in two groups of children who had myelomeningocele. Group I consisted of twenty children who had an Arnold-Chiari Type-II malformation in whom a suboccipital craniectomy (partial occipital craniectomy through the suboccipital route) and cervical laminectomy was done to decompress the brain stem. The average duration of follow-up in this group (excluding one patient) was 4.7 years (range, 2.3 to 10.4 years) after the operation. Group II consisted of twenty children who had myelomeningocele but had not had an operation for decompression. Lateral radiographs of the cervical spine in flexion and extension showed no instability between the occiput and atlas or between the atlas and axis in either group. In contrast, translation between the second and third cervical vertebrae averaged four millimeters in Group I and one millimeter in Group II (p less than 0.01), and angulation between the third and fourth cervical vertebrae averaged 17 degrees in Group I and 6 degrees in Group II (p less than 0.01). Nineteen of the twenty patients in whom a suboccipital craniectomy and cervical laminectomy (Group I) had been done had instability of the cervical spine.
Abnormal tubular handling of sodium and water induced by atrial natriuretic peptide in essential hypertension. Atrial natriuretic peptide (ANP) was given as an intravenous bolus injection (2.0 micrograms kg-1) to 12 essential hypertensive patients (EH) and 13 normotensive control subjects (C) in order to study the effect of ANP on renal glomerular and tubular function using the lithium clearance technique. Urinary sodium excretion (EH, + 370% vs. C, + 120%; P less than 0.001) and urine volume (EH, + 137% vs. C, + 62%; P less than 0.01) increased significantly more in EH than in controls after ANP injection. Glomerular filtration rate, renal plasma flow, and plasma concentrations of angiotensin II, aldosterone and arginine vasopressin remained almost unchanged after ANP injection, whereas the filtration fraction increased to the same extent in both groups. Both proximal (EH, - 15% vs. C, - 5%; P less than 0.01) and distal fractional reabsorption (EH, - 12% vs. C, - 5%; P less than 0.01) of sodium decreased more markedly after ANP in EH than in controls. The increase in plasma cGMP and urinary excretion of cGMP was the same in the two groups. Mean blood pressure decreased and heart rate increased to the same extent in both groups. It is concluded that the increase in urinary sodium excretion and urine volume induced by ANP bolus injection is exaggerated in EH due to a more pronounced reduction in the reabsorption of sodium and water in both the proximal and the distal tubule.
A comparison of the clinical characteristics of first and second primary head and neck cancers. A population-based study. The clinical characteristics of 183 patients with second primary neoplasms in the head and neck region were compared with those of 20,598 patients with one primary tumor in the same region registered during the period 1973 to 1984 in the Surveillance, Epidemiology and End-Results Program. Second primary head and neck tumors were more likely to be diagnosed in a localized stage (47%) than if diagnosed as a single primary tumor (43%), but this difference was not significant. The tumor grade distribution was comparable in both groups. Using Cox proportional hazards modeling with age, sex, race, and stage as covariates, the median survival of patients with first and second head and neck cancer was identical (50 months). The survival of patients with localized second head and neck cancer was shorter than that of patients with single localized tumors (55 versus 102 months, P less than 0.026). Survival for regional tumors was similar (18 versus 21 months, not significant). The 84 second head and neck cancers in which the first head and neck cancer received radiation therapy (RT) had a median survival of 20 months; the 98 cases without prior RT had a median survival of 35 months. The high incidence of localized second cancers was probably due to the more intense surveillance. The worse survival in this group may be a result of prior RT or biologic characteristics of the tumor.
Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement. Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.
Skeletal muscle metabolism and work capacity: a 31P-NMR study of Andean natives and lowlanders. Two metabolic features of altitude-adapted humans are the maximal O2 consumption (VO2max) paradox (higher work rates following acclimatization without increases in VO2max) and the lactate paradox (progressive reductions in muscle and blood lactate with exercise at increasing altitude). To assess underlying mechanisms, we studied six Andean Quechua Indians in La Raya, Peru (4,200 m) and at low altitude (less than 700 m) immediately upon arrival in Canada. The experimental strategy compared whole-body performance tests and single (calf) muscle work capacities in the Andeans with those in groups of sedentary, power-trained, and endurance-trained lowlanders. We used 31P nuclear magnetic resonance spectroscopy to monitor noninvasively changes in concentrations of phosphocreatine [( PCr]), [Pi], [ATP], [PCr]/[PCr] + creatine ([Cr]), [Pi]/[PCr] + [Cr], and pH in the gastrocnemius muscle of subjects exercising to fatigue. Our results indicate that the Andeans 1) are phenotypically unique with respect to measures of anaerobic and aerobic work capacity, 2) despite significantly lower anaerobic capacities, are capable of calf muscle work rates equal to those of highly trained power- and endurance-trained athletes, and 3) compared with endurance-trained athletes with significantly higher VO2max values and power-trained athletes with similar VO2max values, display, respectively, similar and reduced perturbation of all parameters related to the phosphorylation potential and to measurements of [Pi], [PCr], [ATP], and muscle pH derivable from nuclear magnetic resonance. Because the lactate paradox may be explained on the basis of tighter ATP demand-supplying coupling, we postulate that a similar mechanism may explain 1) the high calf muscle work capacities in the Andeans relative to measures of whole-body work capacity, 2) the VO2max paradox, and 3) anecdotal reports of exceptional work capacities in indigenous altitude natives.
Mitogenic response of T-lymphocytes to exercise training and stress. The impact of exercise training and stress on the immune response was examined by measuring the mitogenic response of spleen lymphocytes to the T-cell mitogen concanavalin A (Con-A). Male Sprague-Dawley rats were divided into four groups: sedentary controls (n = 11), handled controls (n = 12), treadmill runners (n = 10), and voluntary runners (n = 11) housed in running wheels. The treadmill group ran at 22 m/min (0.8 mph) for 45 min, 5 days/wk for 8 wk. After the training period, spleen lymphocytes isolated from each rat were incubated with Con-A for 54 h, pulsed with radiolabeled thymidine for 18 h, and counted for tritium activity. Counts per minute per group (means +/- SE) were as follows: sedentary, 6,839 +/- 1,461; handled, 8,959 +/- 1,576; voluntary runners, 13,126 +/- 2,069; and treadmill runners, 18,950 +/- 5,975. One-way analysis of variance and Tukey's highly significant difference test found the counts per minute of the treadmill runners to be significantly different from the counts per minute of the sedentary animals. These results indicate that the responsiveness of spleen lymphocytes to Con-A increases as the level of stress and exercise increases.
Autonomic nervous dysfunction in essential hypertension. Borderline hypertension, a condition in which the blood pressure oscillates between normal and high values, is a predictor of future more severe hypertension. Pathophysiologically, borderline hypertension is different from established hypertension. A large proportion of such patients have elevated cardiac output and a normal vascular resistance. In established hypertension, the output is normal and resistance is elevated. The elevation of cardiac output in borderline hypertension is neurogenic; it can be abolished by an autonomic blockade of the heart. In addition to an increased cardiac sympathetic drive, increased sympathetic tone to the kidney, arterioles, and veins has also been found. In parallel with the hypersympathetic state, patients with borderline hypertension also show decreased parasympathetic tone. The enhanced sympathetic tone leads to a decreased cardiac responsiveness, and eventually, the cardiac output returns to the normal range. High blood pressure causes vascular hypertrophy, and hypertrophic vessels are hyperresponsive to vasoconstriction. These secondary changes in the responsiveness of the heart and blood vessels are the basis of transition from a high cardiac output to high-resistance hypertension. These hemodynamic changes are associated with a downregulation of the sympathetic tone. A picture of an apparently nonneurogenic high-resistance hypertension emerges. Nevertheless, when assessed in regard to the enhanced pressor responsiveness, the sympathetic drive in such patients is still excessive. Despite the apparently normal tone, the sympathetic nervous system continues to play an important pathophysiological role in established hypertension. Borderline hypertension is associated with numerous metabolic abnormalities including obesity and insulin resistance. It is tempting to view all these abnormalities as a common expression of the increased sympathetic drive in hypertension. Explanation of the basis of the association of hypertension and metabolic abnormalities promises to bring new insights into the pathophysiology of two common diseases of civilization: hypertension and diabetes mellitus.
Pitfalls in the diagnosis of drug smuggler's abdomen. Narcotics "body packing" can be detected in abdominal X-rays by the ring shadow caused by air trapped in the packs. In a series of 82 cases admitted for abdominal X-ray in Helsinki, Finland, in 1982 through 1988, we encountered 9 (11.0%) true positives, 3 (3.6%) false positives, and 1 (1.2%) false negative. The false positives were due to the constipation often associated with the narcotics abuse. The false negative X-ray diagnosis was attributable to an inexperienced radiologist. False negatives may also be associated with packets containing marijuana, packs with few wrappings, aluminum-foil coated packs, and machine-packed narcotics. Searching for trapped air in radiographs, repeated X-raying by an experienced radiologist, use of computed tomography, or combined urinary drug screening may be applied to diminish false findings and to avoid unnecessary arrest for the purpose of fecal screening over several days.
A single amino acid substitution in the variable region of the light chain specifically blocks immunoglobulin secretion. Although immunoglobulin light chains are usually secreted in association with heavy chains, free light chains can be secreted by lymphocytes. To identify the structural features of light chains that are essential for their secretion, we mutated a conserved sequence in the variable domain of a lambda I light chain. The effects of the mutations on secretion were assayed by transient expression in COS-1 cells. One mutant (AV60), which replaced Ala-60 with Val, was secreted as efficiently as wild-type lambda I by transfected COS-1 cells. This result was not surprising because secreted lambda II chains contain valine in this position. However, a second lambda I mutant (AV60FS62), which replaced Phe-62 with Ser as well as Ala-60 with Val, was not secreted. This mutant was arrested in the endoplasmic reticulum, as judged by immunofluorescence and by its association with a lumenal endoplasmic reticulum protein, immunoglobulin heavy chain binding protein (BiP). The defect in secretion was not due to gross misfolding of the lambda I chain, since cells cotransfected with AV60FS62 and an immunoglobulin heavy chain gene produced functional antigen-binding antibodies. These assembled IgM molecules were still not secreted. Hence, the replacement of Phe-62 with Ser specifically affects a determinant on the lambda I light chain that is necessary for the intracellular transport of this molecule.
End-systolic regional wall stress-length and stress-shortening relations in an experimental model of normal, ischemic and reperfused myocardium. Assessment of left ventricular function is influenced by a number of hemodynamic factors. The purpose of this study was to evaluate the end-systolic regional wall stress-dimension relation in a series of 25 mongrel dogs. In Group A (n = 18) the regional wall stress-velocity of circumferential fiber shortening relation was measured before and after three interventions: volume infusion, metoprolol infusion and dobutamine infusion. The electrocardiogram, left ventricular pressure and its first derivative (dP/dt), arterial pressure and echocardiograms were recorded at baseline and after phenylephrine administration (to increase afterload). For each dog values for regional wall stress were plotted against the velocity of circumferential fiber shortening. For all dogs the relations were inversely linear (r = -0.65 to -0.98). Volume infusion increased end-diastolic volume (p less than 0.05) without shifting the slope or intercept of the relation, indicating its independence from preload. Dobutamine caused a shift in the intercept to the right but no change in slope and metoprolol shifted the relation to the left without altering the slope. The effect of ischemia and reperfusion on the end-systolic regional wall stress-length relation was examined in Group B (n = 7), at baseline, after 5 min of mid-left anterior descending coronary artery occlusion and after 10 min of reperfusion. Afterload was increased by hydraulic aortic occlusion. Regional wall stress was lowest at baseline, highest during ischemia and intermediate after reperfusion (100.2 +/- 32.1, 193.5 +/- 81.5, 141.9 +/- 67.6 kdyn/cm2, respectively, p less than 0.001). The end-systolic regional wall stress-length relation was linear during baseline, ischemia and reperfusion (r = 0.96, 0.95, 0.98, respectively, p less than 0.05). Ischemia caused an increase in the slope and a shift in the intercept to the right compared with baseline. Reperfusion represented an incomplete return toward baseline. This study demonstrates that the regional wall stress-velocity of circumferential fiber shortening relation is linear, independent of preload, incorporates afterload and is sensitive to changes in contractility. In addition, the regional wall stress-length relation can be measured in a nonhomogeneously contracting left ventricle and is predictably altered by ischemia and reperfusion. This relation may prove useful to determine whether alterations in regional systolic function result from changes in local load or contractility in the left ventricle with a regional wall motion abnormality.
Identification of transforming genes of subgroup A and C strains of Herpesvirus saimiri. Herpesvirus saimiri is an oncogenic herpesvirus that induces rapidly progressing lymphomas in New World primates. Using retrovirus vectors for gene transfer, specific open reading frames of H. saimiri were tested for their ability to transform rodent cells in culture. One open reading frame, designated STP-C488 (for saimiri-transformation-associated protein of the subgroup C strain 488), phenotypically transformed Rat-1 cells, resulting in formation of foci, growth at reduced serum concentration, and growth to higher cell densities. Cells transformed by STP-C488 formed invasive tumors in nude mice. The STP-A11 reading frame of strain 11 (subgroup A) was much less potent in its transforming ability than STP-C488. These results demonstrate the oncogene nature of these two open reading frames and provide a means for studying their transforming functions independent of the rest of the H. saimiri genome.
Arthrodesis with dual plates after failed total knee arthroplasty. Eleven patients were treated by arthrodesis with dual compression plates after failed total knee arthroplasty. All patients had a solid fusion, at an average of 5.6 months after the operation. The complications included one femoral stress fracture and one persistent infection, both of which were treated successfully. Fixation with dual compression plates is a useful technique for the salvage of a failed total knee arthroplasty, even when the patient has an infection. Staggering of the plates may help to prevent late stress fractures.