shukoor65/lab-rag-model huggingface dataset:
The role of exercise in the primary and secondary prevention of coronary artery disease. Over the past 30 years, mortality rates from coronary artery disease (CAD) have decreased by more than 30% in the United States. However, CAD remains the major public health problem in this country. There is now substantial evidence linking exercise training to a reduced risk for CAD and for mortality after myocardial infarction. The actual mechanism by which physical activity aids in reducing the risk for developing or dying from CAD has still to be elucidated. Several highly plausible mechanisms have been postulated, including decreased myocardial oxygen demand, increased myocardial oxygen supply, reduced propensity toward ventricular arrhythmias, reduced platelet aggregation, increased plasma fibrinolytic activity, and modification of multiple CAD risk factors. Irrespective of the precise mechanism, it now appears that lower levels of physical activity are needed to reduce the risk for CAD than are needed to optimize cardiorespiratory fitness. In this regard, we recommend that the type, frequency, intensity, and duration of exercise training be modulated to achieve a weekly energy expenditure of between 14 and 20 kilocalories per kilogram of body weight. Although aerobic activities should be emphasized, muscle strengthening and flexibility exercises should also be incorporated into the training program in order to promote musculoskeletal health.
Impact of resident training on postoperative morbidity in patients undergoing single valve replacement. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease. As one of the requirements of the Department of Veterans Affairs cooperative study on valvular heart disease, operative and postoperative data were prospectively collected in 964 patients undergoing single valve replacement. The procedure was performed either by a resident under the direct supervision of an attending surgeon (49.5%) or by an attending surgeon (50.5%). There was no difference in operative mortality between the two groups of surgeons when adjusted for patient-related and disease-related risk factors. The proportion of patients who had at least one postoperative complication was slightly but not significantly higher in the attending group (35.8% versus 30.4% for aortic valve replacement, 38% versus 28% for mitral valve replacement, and 36% versus 30% for all single valve replacement procedures). As the significance of each complication varies, we weighted each complication to the associated operative mortality to formulate the morbidity score. An expected complication rate for each group was derived from a multivariate logistic model, and the ratio of observed to expected morbidity was calculated to adjust observed morbidity according to the risk of patients. There was no difference in the observed/expected morbidity ratio between the two groups of surgeons. We conclude that currently used teaching techniques and philosophy to educate cardiac surgical residents, which allow them to take progressive responsibility for cardiac surgical procedures, are well justified, and patient care does not suffer when resident training is enhanced.
Bilateral renal hemangiopericytoma. The first reported case of bilateral renal hemangiopericytoma is presented. The 19 previous renal hemangiopericytomas that have been reported in the world literature are reviewed. This lesion has afflicted patients ranging in age from sixteen to sixty-eight years (mean 41 years) with an equal sex distribution. Mortality from hemangiopericytoma of the kidney has been 50 percent, and the primary mode of therapy remains surgical.
Excess mortality in giant cell arteritis. A 13-year departmental sample of 34 patients with definite (biopsy-verified) giant cell arteritis (GCA) was reviewed. The mortality of this material was compared to sex-, age- and time-specific death rates in the Danish population. The standardized mortality ratio (SMR) was 1.8 (95% confidence limits, 1.1-2.8). During the same period 146 patients with probable (not biopsied, but clinically diagnosed in the department) GCA and 85 cases of possible (diagnosed and treated before admission) GCA had been admitted to the department. Those two groups did not differ from the biopsy-verified group with respect to SMR, sex distribution or age. In the group of patients with department-diagnosed GCA (definite + probable = 180 patients), the 95% confidence interval for the SMR of the women included 1.0. In all other subgroups there was a significant excess mortality. Excess mortality has been found in two of seven previous studies on survival in GCA. The prevailing opinion that steroid-treated GCA does not affect the life expectancy of patients is probably not correct.
Dietary Ca2+ prevents NaCl-sensitive hypertension in spontaneously hypertensive rats via sympatholytic and renal effects. NaCl-sensitive spontaneously hypertensive rats (SHR-S) were used to test the hypotheses that dietary Ca2+ supplementation 1) prevents NaCl-sensitive hypertension via a sympatholytic mechanism, and 2) increases diuretic and natriuretic responses to acute volume loading. SHR-S and control WKY rats were begun on one of four diets at age 8 wk: control, high NaCl, high Ca2+, or high NaCl and high Ca2+. In SHR-S, dietary Ca2+ supplementation prevented the NaCl-induced increases in blood pressure and plasma norepinephrine concentrations, the reductions in anterior hypothalamic norepinephrine stores and turnover, and the secondary increases in alpha 2 adrenoceptor number. Thus, Ca2+ prevented NaCl-sensitive hypertension in SHR-S by increasing noradrenergic input to the anterior hypothalamus. High-NaCl-fed SHR-S had impaired diuretic and natriuretic responses to an isotonic volume load; Ca2+ enhanced the ability of these animals to adjust fluid volume rapidly via diuresis and natriuresis. This alteration in renal function may contribute to the hypotensive effect of a high Ca2+ diet in NaCl-sensitive hypertension.
Quinapril, an angiotensin converting enzyme inhibitor, prevents cardiac hypertrophy during episodic hypertension. Six control dogs, six dogs treated with 1.5 mg/kg b.i.d. quinapril, and six dogs treated with 8 mg/kg q.d. minoxidil underwent 6 hours daily of hindquarter compression for 9 weeks. Minoxidil significantly decreased baseline blood pressure (-17 mm Hg; p less than or equal to 0.01), whereas quinapril decreased baseline blood pressure 11 mm Hg but not significantly (p = 0.15). Hindquarter compression elicited blood pressure increases in all three groups (control +18, quinapril +13, minoxidil +19 mm Hg). After 9 weeks, left ventricular mass in control dogs increased 22% (p less than 0.004); a similar increase was seen in minoxidil-treated dogs (+22%, p less than 0.0001) but not in the quinapril-treated group (+4%, p less than 0.15). The increase in left ventricular mass in control dogs was concentric (increased epicardial volume only), whereas in the minoxidil group, the hypertrophy was eccentric (both epicardial and endocardial volumes increased). The minimal hypertrophy in the quinapril group was concentric (no change in epicardial, but a decrease in endocardial volume). Quinapril had little hypotensive effect, but prevented the development of left ventricular hypertrophy, whereas minoxidil did not prevent hypertrophy in spite of its hypotensive effect. The mechanism of this differential effect of direct vasodilation versus converting enzyme inhibition on left ventricular hypertrophy is not fully elucidated. The results with quinapril suggest that some antihypertensive agents may positively affect left ventricular hypertrophy in spite of the absence of a large effect on baseline blood pressure or on blood pressure reactivity.
Vascular endothelial cell growth factor (VEGF) produced by A-431 human epidermoid carcinoma cells and identification of VEGF membrane binding sites. A distinct family of endothelial cell mitogens that are homologous to platelet-derived growth factor has recently been identified. Unlike other known endothelial cell mitogens, these vascular endothelial cell growth factors (VEGFs) are secreted and appear to act specifically on endothelial cells. We have purified VEGF 2083-fold to apparent homogeneity from protein-free culture medium conditioned by A-431 human epidermoid carcinoma cells. This A-431-derived VEGF was characterized as a homodimer composed of 22-kDa subunits with an N-terminal sequence that was similar to VEGFs produced by human HL-60 leukemic and U-937 histiocytic lymphoma cells. A-431 VEGF was used to identify specific and saturable binding sites for VEGF on human umbilical vein endothelial cells (HUVEC). By affinity cross-linking, VEGF-binding site complexes of 230, 170, and 125 kDa were detected on HUVEC. VEGF specifically induced the tyrosine phosphorylation of a 190-kDa polypeptide, which was similar in mass to the largest binding site detected by affinity cross-linking.
Extracorporeal membrane oxygenation in the treatment of neonatal respiratory failure. We report 18 consecutive neonates with severe respiratory failure due to pulmonary hypertension treated with extracorporeal membrane oxygenation. Extracorporeal membrane oxygenation was begun at 52 +/- 36 hours of age with an arterial partial pressure of oxygen (PO2) of 36 +/- 14 mm Hg despite maximal pharmacologic and ventilator support (inspired fraction of oxygen [FiO2], 0.99 +/- 0.03; respiratory rate, 98 +/- 31/min; and positive inspiratory pressure, 54 +/- 11 cm of water). With initial flows of 130 +/- 17 mL/kg per minute, ventilator settings were reduced to the following: FiO2, 0.30; respiratory rates, 15/min; and positive inspiratory pressure, 24 cm of water. Support using extracorporeal membrane oxygenation was gradually reduced to 22% of initial flows and arterial blood samples showed pH 7.48 +/- .05, PO2 of 106 +/- 27 mm Hg, and PCO2 of 36 +/- 5 mm Hg just prior to decannulation. After 107 +/- 45 hours, extracorporeal membrane oxygenation was stopped and infants were extubated 61 +/- 53 hours (median, 46 hours) afterward. There was one death (94.4% survival rate); all survivors were discharged and underwent a follow-up examination at 1 to 27 months of age. Complications included two intracranial hemorrhages (one death and one asymptomatic), one patent ductus arteriosus requiring ligation on extracorporeal membrane oxygenation, and chronic lung disease in one patient. In selected neonates, extracorporeal membrane oxygenation allows for resolution of pulmonary hypertension, results in improved survival, and is associated with a low incidence of chronic lung disease. Extracorporeal membrane oxygenation should be considered in the treatment of severe respiratory failure.
Curative treatment of scalp arteriovenous fistulas by direct puncture and embolization with absolute alcohol. Report of three cases. Three cases of direct arteriovenous fistulas of the scalp (two involving cirsoid aneurysms) are presented. All three patients were treated with direct puncture of the venous pouch and injection of absolute ethyl alcohol during compression of the venous outflow of the fistula. Two of the three patients were cured with this treatment alone. The third patient, with a very high-flow giant fistula, required injection of glue to close the fistula and subsequent surgical extirpation of the resulting hard mass lesion.
Parotid enlargement in children seropositive for human immunodeficiency virus: imaging findings. We investigated the clinical, immunologic, and imaging features of parotid enlargement in 10 children seropositive for human immunodeficiency virus (HIV) who were infected prenatally. In seven patients, sonography revealed many small hypoechoic areas suggestive of lymphoid infiltration. In three older children, large anechoic areas suggesting lymphoepithelial cysts were present. The lesions probably represent generalized lymphoid infiltration akin to pulmonary lymphoid hyperplasia, although only two of our patients had radiologic evidence of pulmonary lymphoid hyperplasia. Four of five of the children with parotid enlargement who had immunologic studies were phenotypically HLA-DR5, an immunophenotype associated with improved immune response, occurring in less than one in four in the normal population. This suggests that painless parotid enlargement may be a good prognostic sign in HIV-seropositive children. Parotid enlargement was found in 10 HIV-positive children from 6 months to 11 years old. All except one were infected prenatally.
Kock pouch procedures: continuing experience and evolution in 135 cases. Between April 1985 and January 1989, 135 consecutive patients underwent construction of a Kock pouch (to the skin in 72 patients, a urethral pouch in 45, an ileorectal pouch in 10 and a hemi-Kock pouch augmentation cystoplasty in 8). The operative mortality (30 days) rate was 4.4%. There were 16 early complications (12.4%) leading to 14 reoperations (11%), with a followup of 6 to 60 months. After Kock pouch to the skin, the late complication rate was 26.1% in the Kock-Skinner technique group and 7.4% in the simplified technique group, and 94.2% of the patients were continent. After a urethral Kock pouch daytime continence was achieved in 93% of the patients within 2 months and nighttime dryness was noted in 65% within 3 months. After an ileorectal Kock pouch all patients were continent day and night, as were those after hemi-Kock pouch augmentation, although 5 of the latter patients required intermittent catheterization.
Infection of human neural cell aggregate cultures with a clinical isolate of cytomegalovirus. Human neural cell aggregate cultures were prepared from dissociated fetal brain tissue and maintained in rotation culture. After 35 days in culture, aggregates had the histologic appearance of dense, immature, neural cells in a tightly packed neuropil. Electron microscopy revealed ultrastructural features suggestive of immature neurons and neuroglia. In addition, neuron-specific enolase and glial fibrillary acidic protein associated with radial glial cells were detected within the aggregates by immunoperoxidase staining. When infected with a laboratory-adapted strain of cytomegalovirus (CMV), [AD169], cells containing large, bizarre, nuclei and CMV-induced intranuclear inclusion bodies were dispersed throughout the aggregates at 16 days postinfection. In situ hybridization using a CMV-specific DNA probe and electron microscopy confirmed the presence of virus sequences as well as virus particles at histologic sites of cytopathology. In sharp contrast, aggregate cultures infected with a CMV strain recovered from the retina of an acquired immune deficiency syndrome (AIDS) patient with CMV retinitis and encephalitis displayed distinct foci of cytopathology at 23 days postinfection, a pattern not observed in CMV [AD169]-infected aggregates. Our findings suggest that human neural cell aggregates represent a a promising multicellular non-neoplastic culture system in which to study the replication of human neurotropic viruses within neural tissue.
Effects of variable dose milrinone in patients with low cardiac output after cardiac surgery. European Multicenter Trial Group. We studied 99 adult patients after elective cardiac surgery who had low cardiac output (cardiac index less than 2.5 L/min/m2) in spite of adequate cardiac filling pressure (pulmonary capillary wedge pressure less than 8 mm Hg). Patients received milrinone by loading dose (50 micrograms/kg over a 10-minute period), followed by a continuous infusion of either 0.375, 0.5, or 0.75 micrograms/kg/min (low-, middle-, and high-dose groups, respectively) given for a minimum of 12 hours. Patients were allocated to each dosage group sequentially, not randomly. Hemodynamic measurements were made before the loading dose and at 15, 30, 45, and 60 minutes, 3, 6, and 12 hours after the start of milrinone therapy. Further measurements were made at 2 and 4 hours after treatment was stopped. Milrinone therapy was associated with a rapid, well-sustained, and highly significant increase in cardiac index in all three dose groups (p less than 0.001), and a similar fall occurred in pulmonary capillary wedge pressure in all groups (p less than 0.001). Significant increases occurred in heart rate in all three groups (p less than 0.001). Systemic and pulmonary vascular resistance also fell significantly, although changes in this latter parameter were less predictable and more dose dependent. Few serious treatment-related adverse effects were seen. We conclude that intravenous milrinone is an effective and safe therapy for the treatment of low output states after cardiac surgery.
Efficacy of fixed minidose warfarin prophylaxis in total hip replacement. OBJECTIVE--To determine whether a small fixed perioperative dose of warfarin would prevent deep vein thrombosis after total hip replacement. DESIGN--Prospective, randomised, double blind placebo controlled trial. SETTING--Winford Orthopaedic Hospital, Bristol. SUBJECTS--148 patients having primary total hip replacement. INTERVENTION--Warfarin 1 mg given daily for one week before and three weeks after surgery. MAIN OUTCOME MEASURE--Deep vein thrombosis diagnosed by the iodine-125 labelled fibrinogen uptake method. RESULTS--Deep vein thrombosis occurred in 25 (34%) of the patients given warfarin and 19 (26%) of the controls (difference 8%; 95% confidence interval -6.8% to 22.8%). CONCLUSION--Fixed minidose warfarin does not prevent deep vein thrombosis after total hip replacement.
Surgical versus medical treatment for epilepsy. I. Outcome related to survival, seizures, and neurologic deficit. We conducted a retrospective parallel longitudinal cohort study comparing surgical and medical treatment for epilepsy. The surgical group contained 201 patients treated with resective surgery for epilepsy in Norway since the first operation in 1949 until January 1988. The 185 control group patients treated medically only were closely matched for year of treatment, age at treatment, sex, seizure type, and neurologic deficit before treatment. There was no significant difference in survival between the two groups. The total monthly seizure frequency in the first and second year after operation and last year of registration (median 9 years) was significantly lower in the surgical group than in the control group (Mann-Whitney U test, two-tailed p less than 0.0001). The patterns were similar, with significant differences for subgroups with similar pretreatment status, such as seizure frequency, age, etiology and EEG-focality. Twenty-three and four-tenths percent (n = 40) of the surgically treated, and 2.9% of the controls had contracted neurologic deficits within 2 years after treatment. The difference was significant (chi square = 32.89, p less than 0.0001). Psychosis or permanent psychotic symptoms were reported in 6.7% (n = 11) of the surgically treated patients, and we suspect a higher proportion of psychotic development in the surgical group than in the control group. We conclude that surgical treatment for partial epilepsy is more successful than medical treatment in producing seizure reduction, provided the indications for operation exist. Surgical treatment produces more neurologic deficits than medical treatment (and possibly more psychiatric morbidity), and this factor must be weighed against the reduction in seizure frequency. The two treatments are equal for longterm survival.
p53 mutations in human cancers. Mutations in the evolutionarily conserved codons of the p53 tumor suppressor gene are common in diverse types of human cancer. The p53 mutational spectrum differs among cancers of the colon, lung, esophagus, breast, liver, brain, reticuloendothelial tissues, and hemopoietic tissues. Analysis of these mutations can provide clues to the etiology of these diverse tumors and to the function of specific regions of p53. Transitions predominate in colon, brain, and lymphoid malignancies, whereas G:C to T:A transversions are the most frequent substitutions observed in cancers of the lung and liver. Mutations at A:T base pairs are seen more frequently in esophageal carcinomas than in other solid tumors. Most transitions in colorectal carcinomas, brain tumors, leukemias, and lymphomas are at CpG dinucleotide mutational hot spots. G to T transversions in lung, breast, and esophageal carcinomas are dispersed among numerous codons. In liver tumors in persons from geographic areas in which both aflatoxin B1 and hepatitis B virus are cancer risk factors, most mutations are at one nucleotide pair of codon 249. These differences may reflect the etiological contributions of both exogenous and endogenous factors to human carcinogenesis.
In vitro cholesterol gallstone dissolution: comparison of methyl tert-butyl ether with three new ester solvents. The in vitro effectiveness of three new cholesterol gallstone solvents that have a potential for clinical use--ethyl propionate, isopropyl acetate, and n-propyl acetate--was compared with that of the well-known cholesterol solvent methyl tert-butyl ether (MTBE). Ten sets of matched gallstones were initially weighed, imaged with radiography and computed tomography (CT), and analyzed for content. One stone from each set was incubated in one of the four solvents at 37 degrees C. Solvents were changed at 30-minute intervals. The study was stopped either when the stones were completely dissolved or at the end of 7 hours. Any residual fragments were weighed, reimaged, and reanalyzed for content. There were no statistical differences between dissolution times of the stones in MTBE compared with those in the three new solvents. Ethyl propionate and n-propyl acetate appear to be as efficacious as MTBE in dissolving cholesterol stones and could be attractive alternatives for gallstone chemolysis.
The economic implications of high-risk abdominal aortic aneurysms. Financial data of 102 patients undergoing elective and emergent abdominal aortic aneurysm repair over a 3-year period were evaluated in terms of postoperative length of stay, net revenue, total standard cost, and net margin. Cost reimbursement was based on diagnosis related group payments. Aneurysm repairs were classified as emergent, high-risk elective, or low-risk elective. A net loss of $409,459 was noted for the entire series. Emergent repairs, although only 12% of the population, accounted for 73% of total losses, with a mean loss of $24,655/patient. The mean net loss in the high-risk elective group was $3590/patient, and a net gain of $1132/patient was noted in the low-risk elective group. Length of stay outliers, defined as length of stay greater than 28 days, contributed to the bulk of the losses in the elective series and were predominant in the high-risk group. No preoperative comorbidity, other than high-risk classification, predicted outlier status. Length of stay correlated with total standard costs in all categories of aneurysm repair. Third party payment for length of stay outliers was inadequate; the diagnosis related group system warrants revision so that outlier reimbursement will be based on a tiered system derived from length of stay.