shukoor65/lab-rag-model huggingface dataset:
Sympathetic neural responses to induced ventricular tachycardia. Although sympathetic mechanisms play a major role in buffering abrupt arterial pressure reductions, including those that occur during tachyarrhythmias, human sympathetic nervous system responses to ventricular tachycardia have not been measured. Muscle sympathetic nerve activity was recorded directly from the peroneal nerve in 16 patients during diagnostic induction of 19 episodes of sustained monomorphic ventricular tachycardia (average rate 189 beats/min, range 130 to 250). Average systolic and diastolic pressures decreased from 149/78 to 61/49 mm Hg by 10 s and increased toward baseline levels to 88/64 mm Hg by 1 min of ventricular tachycardia. Average sympathetic nerve activity increased by 92% at 10 s in direct proportion to arterial pressure reductions and in inverse proportion to ventricular rate and remained 83% above baseline levels at 1 min. The late recovery of arterial pressure during ventricular tachycardia was related significantly to the magnitude of early sympathetic responses. Sympathetic activity tended to lose its discrete bursting pattern during ventricular tachycardia, and power spectral analysis showed that the large sympathetic peaks at the heart rate frequency present during sinus rhythm are absent during ventricular tachycardia. This study is the first to delineate human sympathetic nervous system responses to ventricular tachycardia. The results suggest that in the patients studied, large early sympathetic surges differed from those that occur during sinus rhythm and contributed to hemodynamic stability during ventricular tachycardia.
Intermittent pneumatic compression versus coumadin. Prevention of deep vein thrombosis in lower-extremity total joint arthroplasty. One hundred forty-nine consecutive patients requiring lower extremity total joint arthroplasty were randomized to either coumadin (52 patients) or intermittent pneumatic compression (48 patients) as prophylaxis against deep vein thrombosis (DVT). Forty-nine patients were excluded. When fully ambulatory, the presence or absence of DVT was diagnosed by ascending venography (90% of patients), nuclear venography, venous dopplers, or impedence plethysmography. The two groups were similar in average age (64 years), indication for arthroplasty (pain because of arthritis in 90%), gender (98% male), and average number of risk factors (2.4). Twenty-five percent of patients on coumadin and 25% of patients on intermittent pneumatic compression (IPC) developed DVT. IPC was more effective than coumadin following primary total hip arthroplasties (THAs) (16% versus 24% incidence DVT); coumadin was more effective than IPC following primary total knee arthroplasties (TKAs) (19% versus 32% incidence of DVT). DVT developed in 36% of patients following revision arthroplasty. Seventy-five percent of all thrombi were proximal. Both IPC and coumadin were found to be safe; there was no increased perioperative bleeding in the coumadin group. Of three postoperative deaths, one was possibly due to pulmonary embolism (PE).
Effect of milacemide on audiogenic seizures and cortical (Na+, K+)-ATPase of DBA/2J mice. Milacemide (MLM, CP 1552 S, 2-N-pentylaminoacetamide), a glycinamide derivative, is currently being evaluated clinically for antiepileptic activity. Anticonvulsant properties have been shown in various animal models, but the mechanism of action of MLM is unclear. We studied its activity in audiogenic seizures of DBA/2J mice. MLM was effective in inhibiting the convulsions induced by sound with a biphasic dose-effect relation. The ED50 was 109 mg/kg orally against tonic extension. Higher doses were necessary to abolish clonic convulsion and running response. Because impaired cerebral (Na+, K+)-ATPase activity is supposed to play a role in epileptogenesis, we tested MLM on in vitro cortical enzymatic activity of DBA/2J mice. Basal (Na+, K+)-ATPase activity was unchanged by several concentrations of MLM in normal C57BL/6J and audiogenic DBA/2J mice. K+ activation (from 3 to 18 mM) of (Na+, K+)-ATPase is abolished in DBA/2J mice as compared with C57BL/6J mice, suggesting impaired glial (Na+, K+)-ATPase. In the presence of MLM (from 30 to 1000 mg/L), cortical (Na+, K+)-ATPase of DBA/2J mice is activated by high concentrations of K+, as in C57BL/6J mice. Results suggest that the antiepileptic activity of MLM in audiogenic mice may be secondary to an activation of a deficient glial (Na+, K+)-ATPase.
Cardiovascular effects of isradipine in essential hypertension. The immediate and short-term cardiovascular effects of oral isradipine therapy were evaluated in 11 patients with mild to moderate systemic hypertension. Isradipine, 5 mg administered orally, induced a significant reduction in arterial pressure from 165 +/- 6/88 +/- 3 mm Hg to 140 +/- 5/76 +/- 2 mm Hg (p less than 0.001) within 2.5 hours by a decrease in total peripheral resistance associated with an increase in heart rate and cardiac output. Contrary to the acute effect, oral therapy with isradipine for 3 months reduced arterial pressure through a decrease in total peripheral resistance but without causing an increase in heart rate or cardiac output or activation of the sympathetic nervous system. Isradipine slightly reduced left ventricular mass and improved cardiac systolic function and left ventricular filling. Renal blood flow increased, and renal vascular resistance (p less than 0.01) and total blood volume (p less than 0.002) decreased without a change in either sodium excretion or body weight. Thus, isradipine, when given for 3 months, decreased arterial pressure by reducing total peripheral resistance without activation of reflexive mechanisms. Its favorable effects on systemic hemodynamics, total blood volume, renal blood flow, and cardiac structure and function suggest isradipine to be an excellent choice for antihypertensive therapy.
Corneal phaeohyphomycosis caused by Wangiella dermatitidis. A case is described of a corneal abscess of the left eye of a patient, male, 35 years, from which there was found in pure culture a mycotic micro-organism, Exophiala (Wangiella) dermatitidis, determined also in the native preparation from the pus. The patient is feeble-minded, suffers from von Recklinghausen's disease and has an impairment of the immune system (above all the reduction of T lymphocytes).
Influence of hypertension and dietary copper on indexes of copper status in rats. The Dahl salt-sensitive rat was used to investigate the effect of hypertension on indexes of copper status and to determine the extent to which dietary manipulation of copper attenuated, or exacerbated, the rate of sodium chloride-induced hypertension. Weanling salt-sensitive rats were fed, in a 2 x 3 factorial design, one of six diets that contained one of three levels of copper (2.0 micrograms/g marginal, 12 micrograms/g adequate, or 50 micrograms/g supplemental) and either control (0.4%) or high (4%) levels of sodium. Diets were fed to the rats for 11 weeks. Rats fed the high sodium diets were characterized by high plasma copper concentrations and ceruloplasmin activities compared with their respective control sodium rats. The magnitude of the sodium-induced rise in plasma copper and ceruloplasmin was affected by dietary copper intake; however, dietary copper intake had no effect on the development of hypertension in the high sodium groups. These results suggest that altered copper metabolism is secondary, rather than primary, to the development of sodium chloride-induced hypertension in the salt-sensitive rat. Red blood cell superoxide dismutase activity was reduced in rats fed the low copper diets compared with the adequate and supplemented copper groups. At the lower levels of copper intake, sodium chloride-induced hypertension increased red blood cell superoxide dismutase activity in a manner consistent with the plasma copper and ceruloplasmin changes observed. However, at adequate or supplemental levels of dietary copper, red blood cell superoxide dismutase activity plateaued, suggesting possible saturation of copper at sites of hematopoeisis.
Intestinal ischemia associated with cardio-pulmonary-bypass surgery: a life threatening complication. Intestinal ischemia following open heart surgery is rare but nevertheless extremely dangerous and the causes are still unclear. The purpose of this study was to evaluate the factors influencing the occurrence and outcome of patients with this complication. At our institution between 1985 and 1989 1712 patients underwent open heart surgery and 4 female patients suffered from intestinal ischemia. The early mortality was 2.5% for the whole group and 100% for the group with intestinal ischemia. All these 4 patients were elderly and had a history of hypertension and hyperlipoproteinemia. Three of the four patients with intestinal ischemia had various risk factors for thromboembolic events such as pre-existing occlusive arterial disease and cardiac dysrhythmias or had a complicated postoperative course. In two patients an enormous increase in serum lactate to over 10 mmol/l occurred prior to the intestinal ischemia. We therefore consider advancing age, female gender and a susceptibility for thromboembolic events as important risk factors for the development of intestinal ischemia. A serum lactate over 10 mmol/l should lead to an aggressive diagnostic and therapeutic approach including exploratory laparotomy.
Mitogenic effects of coagulation factor XII and factor XIIa on HepG2 cells. The structure of coagulation factor XII (Hageman factor), inferred from its DNA sequence, includes two epidermal growth factor (EGF)-homologous domains in its amino-terminal region. This suggests that factor XII may exhibit EGF-like activities. Reciprocal antigenic cross-reactivity between factor XII and EGF was shown by exposing purified human factor XII or mouse EGF to anti-mouse EGF or anti-human factor XII. Western blot analysis showed that anti-mouse EGF recognized intact factor XII at 80 kDa. Together, these results suggest that the EGF-homologous domains are accessible for anti-EGF binding in native factor XII. To determine whether factor XII has mitogenic activity, HepG2 or L cells (10(4) cells per well) were grown in serum-free medium in the presence or absence of factor XII or kaolin-activated factor XII (factor XIIa). Both factors XII and XIIa (6.0 micrograms/ml) enhanced cell proliferation by approximately 2-fold (P less than 0.001 and P less than 0.005, respectively). In contrast, L cells, which are not EGF target cells, were not affected by either factor XII or factor XIIa. Various doses of factor XII enhanced cell proliferation, [3H]thymidine incorporation, and [3H]leucine incorporation in HepG2 cells cultured under the same conditions. These data indicate that factor XII, like EGF, is a mitogen for HepG2 cells and suggest a possible autocrine role in the liver.
Stress testing in the period after infarction. Dipyridamole echocardiography is gaining popularity as an exercise-independent diagnostic method in patients with suspected or demonstrable coronary artery disease. To assess its safety, feasibility, and diagnostic accuracy in patients recovering from uncomplicated acute myocardial infarction, 131 patients had the test before hospital discharge. The results were compared with those of maximum treadmill testing. We found that dipyridamole-induced transient asynergy remote from the infarct zone was more sensitive (74% versus 53%, p less than 0.05) and specific (97% versus 68%, p less than 0.01) than treadmill testing for detecting multivessel coronary artery disease. In a subgroup of 42 patients treated with thrombolytic therapy, dipyridamole echocardiography was able to detect in 27 the presence of jeopardized but viable myocardium in the infarct zone. An excellent correlation was found between dipyridamole echocardiography responses and infarct vessel patency. Finally, the prognostic impact of dipyridamole echocardiography on patients recovering from acute myocardial infarction was assessed in a consecutive series of 151 patients. Eighteen months of event-free survival was significantly different in patients with positive versus negative dipyridamole echocardiography results (76.1% versus 50.8%, p less than 0.01). The test was also superior to treadmill testing in predicting cardiac events. Thus, dipyridamole echocardiography performed early after acute myocardial infarction is safe, feasible, and accurate for predicting the extent of coronary artery disease and 18-month clinical outcome.
Fluid resuscitation with deferoxamine prevents systemic burn-induced oxidant injury. We studied the effect of deferoxamine (DFO) infused after burns on hemodynamic stability as well as local and systemic inflammation and oxidant-induced lipid peroxidation. Eighteen anesthetized sheep were given a 40% of total body surface burn and fluid resuscitated to restore oxygen delivery (DO2) and filling pressures to baseline values. Animals were resuscitated with lactated Ringer's (LR) alone or LR plus 1,500 ml of a 5% hetastarch complexed with DFO (8 mg/ml). Animals were killed 6 hours postburn. The sheep resuscitated with LR and LR plus hetastarch demonstrated significant lung inflammation and significant increases in lung and liver malondialdehyde (MDA) from controls of 47 +/- 6 and 110 +/- 7 nMol/gm to 63 +/- 13 and 202 +/- 59 for LR and 67 +/- 4 and 211 +/- 9 for LR + hetastarch, respectively. The group resuscitated with hetastarch alone required 15% less fluid. VO2 returned to baseline values in both groups by 2 hours. Resuscitation with the 5% hetastarch-DFO decreased total fluids by 30% over LR and prevented the increase in lung and liver MDA. In addition, postburn VO2 increased by 25% above baseline values. Burn tissue edema, measured as protein-rich lymph flow, was significantly increased with the administration of DFO compared with the other groups. We conclude that DFO used for burn resuscitation prevents systemic lipid peroxidation and decreases the vascular leak in nonburn tissues while also increasing O2 utilization. Resuscitation with hetastarch-DFO may accentuate burn tissue edema, possibly by increased perfusion of burn tissue.
Determinants of genital human papillomavirus infection in young women Carcinoma of the cervix has several well-established epidemiologic risk factors, including multiple sexual partners and early age at first intercourse. Human papillomavirus (HPV) infection appears to have an etiologic role in the development of cervical neoplasia, but evidence linking HPV infection to known risk factors for cervical cancer has been inconsistent. The lack of expected correlations may be due to the inaccuracy of HPV assays previously used. A polymerase chain reaction DNA amplification method for the detection of HPV was used to investigate the determinants of genital HPV infection in a cross-sectional sample of 467 women attending a university health service. In contrast to studies using less accurate detection methods, the risk factors for HPV infection found here were consistent with those for cervical neoplasia. The risk of HPV infection was strongly and independently associated with increasing numbers of sexual partners in a lifetime, use of oral contraceptives, younger age, and black race. Age at first intercourse, smoking, and history of a prior sexually transmitted disease were correlated with, but not independently predictive of, HPV infection. These results demonstrate that the key risk factors for cervical carcinoma are strongly associated with genital HPV infection. This correlation suggests that HPV has an etiologic role in cervical neoplasia and reaffirms the sexual route of HPV transmission.
Thrombolysis in Myocardial Infarction (TIMI) phase II trial: outcome comparison of a "conservative strategy" in community versus tertiary hospitals. The TIMI Research Group In the conservative strategy arm of phase II of the Thrombolysis in Myocardial Infarction (TIMI) trial, 1,461 patients were treated with intravenous recombinant tissue-type plasminogen activator (rt-PA). Coronary angiography, with angioplasty if feasible, was to be performed only for recurrent spontaneous or exercise-induced ischemia. In this study results in patients treated by this strategy in community and tertiary hospitals are compared. Despite similar baseline findings in the two groups, coronary angiography was performed within 42 days in more patients (542 [48%] of 1,155) initially admitted to a tertiary hospital (on-site coronary angiography/angioplasty available) than in those (94 [32%] of 306) admitted to a community hospital (transfer to tertiary hospital for coronary angiography/angioplasty) (p less than 0.001). This different approach resulted in a greater use of coronary angioplasty (203 [18%] of 1,155 versus 32 [11%] of 306, p less than 0.01), coronary artery bypass surgery (133 [12%] of 1,155 versus 23 [8%] of 306, p less than 0.05) and blood transfusions (139 [12%] of 1,155 versus 17 [5.5%] of 306, p less than 0.001) in patients admitted to a tertiary than to a community hospital. However, there were no significant differences between the two groups in mortality, recurrent myocardial infarction or left ventricular function. These results demonstrate that a conservative strategy after treatment of acute myocardial infarction with rt-PA is applicable in the community hospital setting.
Physiologic adaptations to prolonged high-intensity exercise training in patients with coronary artery disease. Exercise training elicits numerous beneficial adaptations in patients with coronary artery disease (CAD), but until 10 yr ago these adaptations were generally believed to be peripheral adaptations rather than improvements in myocardial blood supply. However, animal models of CAD have been shown to elicit improvements in myocardial blood flow and left ventricular performance with prolonged, intense exercise training. More recently we have provided electrocardiographic, echocardiographic hemodynamic, and radionuclide evidence of central cardiovascular adaptations in patients with CAD after a year-long program of 1 h of exercise at 70-90% of VO2max 5 d.wk(-1). These training-induced adaptations are consistent with an improvement in myocardial oxygenation and concomitantly an enhanced left ventricular function in these patients. This program also resulted in improvements in glucose tolerance, insulin sensitivity, and plasma lipoprotein-lipid profile. We have also shown that these beneficial cardiovascular and metabolic adaptations are maintained during six additional years of training in patients with CAD. These results do not imply that all patients with CAD should initiate such an intense training program, but rather that, in selected patients undergoing a training stimulus well in excess of that conventionally prescribed for coronary patients, the training-induced adaptations may be substantially greater than previously believed.
Routine imaging studies for the posttreatment surveillance of breast and colorectal carcinoma. Current recommendations on follow-up procedures for patients who have been treated for cancer include imaging studies and other laboratory tests at relatively frequent intervals. At least two questions should be asked to evaluate the benefits of this practice for patients: Do frequent routine surveillance tests detect recurrences "earlier" in asymptomatic patients? and Does earlier treatment of these recurrences reduce morbidity or prolong survival? The practical import of surveillance with imaging and laboratory tests for recurrence in patients with cancer of the breast and colon is discussed. Reported autopsy data, findings at elective reoperation, and clinical data have been examined to ascertain the justification for routine periodic tests in the treated but asymptomatic patient. It is concluded that earlier detection of a local recurrence or of metastatic disease through periodic tests in the asymptomatic patient with breast or colon cancer rarely alters the treatment or the outcome. A notable exception is regular screening mammography following treatment for adenocarcinoma of the breast.
A follow-up study of colonic epithelial proliferation as a biomarker ina Native-American family with hereditary nonpolyposis colon cancer. A 7-year follow-up study of colonic mucosa proliferation markers was conducted on members of a Native-American family with hereditary nonpolyposis colon cancer. Reproducibility of a tritiated thymidine autoradiography assay for labeling indexes during this 7-year biologically significant time frame was established. A good correlation between tritiated thymidine and a newer technique, bromodeoxyuridine immunoperoxidase staining, was seen. No confounding effect could be attributed to standard colon preparation. On average, both baseline and follow-up values for epithelial proliferation were within the accepted normal range. The presence of essentially normal labeling indexes among colon cancer patients and their high-risk offspring suggests the possibility of the significant effect of dietary factors in reducing proliferation. Such factors may account for the low risk of colon cancer that characterizes the Native-American population in the American Southwest.
High-dose intramuscular triamcinolone in severe, chronic, life-threatening asthma [published erratum appears in N Engl J Med 1991 May 9;324(19):1380] BACKGROUND. Despite oral corticosteroid therapy, some patients with asthma have frequent exacerbations requiring emergency room visits, hospitalization, and occasionally, mechanical ventilation. We compared the effects of high-dose intramuscular triamcinolone with oral prednisone in patients with severe chronic asthma. METHODS. In a double-blind, placebo-controlled, cross-over study that spanned all seasons, we treated 12 patients with high-dose intramuscular triamcinolone (360 mg over the first three days of the treatment period) or low-dose oral prednisone (median dose, 12.5 mg per day throughout the period; range 0 to 30). The two three-month treatment periods were separated by a three-month washout period. During all periods the patients were allowed to take additional doses of prednisone for acute exacerbations of asthma. RESULTS. After receiving triamcinolone, the patients had significantly better peak expiratory flow rates than while receiving prednisone (the average [+/- SEM] weekly percent of the predicted value during the triamcinolone period was 91.5 +/- 6.9, as compared with 75.0 +/- 5.9 for the prednisone period; P less than 0.05). During the prednisone period there were 21 emergency room visits and 10 hospitalizations, but there were none during the triamcinolone period (P less than 0.05). There were two episodes of ventilatory failure during the prednisone period. Total steroid doses were significantly smaller during the triamcinolone period than during the prednisone period (P less than 0.04). Steroidal side effects were more pronounced after treatment with triamcinolone than after treatment with prednisone (P less than 0.1). CONCLUSIONS. We conclude that high-dose intramuscular triamcinolone is more effective than low-dose prednisone in patients with severe, chronic, life-threatening asthma, but steroidal side effects are somewhat worse.