123rc/medical_text huggingface dataset:
An assault on old friends: thiazide diuretics under siege. The adverse biochemical effects of thiazide use are of uncertain clinical significance. Thiazides raise LDL cholesterol only slightly in long-term studies and do not decrease HDL cholesterol. The evidence linking thiazide-induced hypokalemia with arrhythmias and sudden death is tenuous at best. Thiazide diuretics cause glucose intolerance, but no strong evidence has been advanced to suggest that this is dangerous. Because these effects are probably related to hypokalemia, a randomized trial comparing the effects of thiazides with thiazides plus a potassium-sparing diuretic on LDL cholesterol, ectopy on 48 hour ambulatory cardiac monitoring, fasting glucose and insulin, and post-glucose tolerance glucose and insulin would be of interest. The most compelling reason for continuing to use thiazides is that they have been shown in long-term randomized studies to reduce cardiovascular risk. Beta-blockers are the only other class of anti-hypertensive agent for which this claim can be made. The importance of long-term clinical trials in assessing the efficacy and toxicity of therapeutic agents is illustrated by the study that found clofibrate reduced cholesterol levels and coronary disease but increased total mortality. This finding remained undetected until a large randomized long-term trial was completed. Thiazide diuretics have not reduced the rate of coronary disease to the degree expected from epidemiologic studies, but the short length of the randomized trials may be responsible. It is not clear that other anti-hypertensive agents will be superior. Thiazides are less expensive than other anti-hypertensive agents being touted as metabolically safer; the cost issue is not a trivial matter.
Relation of meat, fat, and fiber intake to the risk of colon cancer in a prospective study among women. BACKGROUND. The rates of colon cancer in various countries are strongly correlated with the per capita consumption of red meat and animal fat and, to a lesser degree, inversely associated with the consumption of fiber. METHODS. We conducted a prospective study among 88,751 women 34 to 59 years old and without a history of cancer, inflammatory bowel disease, or familial polyposis who completed a dietary questionnaire in 1980. By 1986, during 512,488 person-years of follow-up, 150 incident cases of colon cancer had been documented. RESULTS. After adjustment for total energy intake, animal fat was positively associated with the risk of colon cancer (P for trend = 0.01); the relative risk for the highest as compared with the lowest quintile was 1.89 (95 percent confidence interval, 1.13 to 3.15). No association was found for vegetable fat. The relative risk of colon cancer in women who ate beef, pork, or lamb as a main dish every day was 2.49 (95 percent confidence interval, 1.24 to 5.03), as compared with those reporting consumption less than once a month. Processed meats and liver were also significantly associated with increased risk, whereas fish and chicken without skin were related to decreased risk. The ratio of the intake of red meat to the intake of chicken and fish was particularly strongly associated with an increased incidence of colon cancer (P for trend = 0.0005); the relative risk for women in the highest quintile of this ratio as compared with those in the lowest quintile was 2.49 (95 percent confidence interval, 1.50 to 4.13). A low intake of fiber from fruits appeared to contribute to the risk of colon cancer, but this relation was not statistically independent of meat intake. CONCLUSIONS. These prospective data provide evidence for the hypothesis that a high intake of animal fat increases the risk of colon cancer, and they support existing recommendations to substitute fish and chicken for meats high in fat.
Emboli in infective endocarditis: the prognostic value of echocardiography. OBJECTIVE: To determine whether vegetations visualized on two-dimensional echocardiography are an independent risk factor for the development of subsequent emboli in patients with infective endocarditis and to assess the timing of emboli relative to the initiation of antimicrobial therapy. DESIGN: Investigator-blinded, retrospective incidence cohort study. SETTING: Tertiary referral center. PATIENTS: Patients with left-sided native valve infective endocarditis who had two-dimensional echocardiography within 72 hours of beginning antimicrobial therapy. MEASUREMENTS AND MAIN RESULTS: The crude incidence rate of first embolic events in patients receiving antimicrobial therapy was 6.2 per 1000 patient-days (95% CI, 4.2 to 9.2). The rates in patients with and without vegetations were 7.1 and 4.9 per 1000 patient-days, respectively (incidence rate ratio, 1.4; 95% CI, 0.6 to 3.3). The relation between vegetations and risk for emboli was microorganism-dependent: Stratified incidence rate ratios were 6.9 (95% CI, 1.1 to 42.5; P less than 0.05) and 1.0 (95% CI, 0.2 to 3.9) for viridans streptococcal and Staphylococcus aureus endocarditis, respectively. The rate of first embolic events diminished over time (P less than 0.001), falling from 13 per 1000 patient-days during the first week of therapy to less than 1.2 per 1000 patient-days after completion of the second week of therapy. CONCLUSIONS: Overall, the presence of vegetations on echocardiography was not associated with a significantly higher risk for embolus in patients with left-sided native valve infective endocarditis. The relative risk for embolic events associated with echocardiographically visualized vegetations may be microorganism-dependent, with a significantly increased risk seen only in patients with viridans streptococcal infection. The rate of embolic events declines with time after initiation of antimicrobial treatment.
Recurrent herpetic keratitis: failure to detect herpes simplex virus infection using the Syva MicroTrak HSV1/HSV2 direct specimen identification/typing test. A 35-year-old man had developed recurrent herpetic keratitis characterized by dendritic keratitis at intervals of a year. We were able to culture cytopathic agents repeatedly from his lesions by inoculating Vero cells. The cultures yielded definitive evidence of a virus that caused a cytopathic effect within 3 days. However, these virus strains could not be identified as herpes simplex virus (HSV) in immunofluorescence assays using the Syva MicroTrak HSV1/HSV2 direct specimen identification/typing test. Rather they were identified as strains of HSV type 1 (HSV-1) on the basis of plaque morphology, neutralization tests, electron-microscopic examination and DNA restriction endonuclease analysis. Our results allow us to assume the existence of HSV-1 strains isolated clinically that are negative to analysis using the Syva Micro-Trak HSV1/HSV2 direct specimen identification/typing test.
Yield from total skin examination and effectiveness of skin cancer awareness program. Findings in 874 new dermatology patients. The authors reviewed 874 dermatology charts to assess the acceptance rate of total skin examination (TSE), incidental skin findings, and patient compliance regarding treatment recommendations. Of the 874 new dermatology patients studied, 707 (80.9%) agreed to TSE. Important incidental findings were found in 151 (21.4%). These included: (1) biopsy specimen-confirmed malignant tumors (malignant melanoma, lentigo maligna, and basal cell and squamous cell carcinoma) in 24 of the 707 patients (3.4%), (2) biopsy specimen-confirmed premalignant tumors (actinic keratosis with dysplasia, Bowenoid actinic keratosis, Bowenoid papulosis, and lentigo with dysplasia, in five (0.7%), (3) clinically diagnosed premalignant actinic keratosis in 64 (9.1%), (4) biopsy specimen-confirmed dysplastic nevi in 17 (2.4%), and (5) congenital nevi in 41 (5.8%). Only 4.2% of the patients returned for a yearly TSE, and only 6.0% were found to follow all recommendations for monthly self examination, yearly professional examination, and sun protection. It is concluded that TSE for all new patients, and on a yearly basis for all return patients, is valuable in the detection of many skin conditions and allows skin cancer screening to be done, since patients for the most part do not follow recommendations for at-home screening.
Accuracy and reproducibility of quantitative coronary arteriography using 6 and 8 French catheters with cine angiographic acquisition. To determine the suitability of 6 French catheters for quantitative coronary arteriography, the relative accuracy and reproducibility of one type of these catheters was compared to that obtained with standard 8 French catheters in 20 stenoses. Duplicate injections with polyurethane 6 French catheters were obtained using hand and power injection technique with cineangiographic acquisition (four 6 French catheter injections total per stenosis). Measurements of both percent diameter stenosis and absolute dimensions were compared to those obtained with hand injection and cine acquisition using 8 French catheters as a "gold standard." While the reproducibility of dimension determination with the 6 French catheter was generally similar to that obtained with the 8 French catheter (0.27 +/- 0.23 mm for absolute diameter and 8.1 +/- 7.4% for percent diameter stenosis), accuracy was significantly less for the 6 French catheter for measurement of absolute dimensions. Thus, while apparently well suited for serial measurements of the same stenoses, 6 French catheters may not be as accurate in the determination of absolute artery dimensions as 8 French catheters.
Time course of cellular enzyme release in dog heart injury. The transport time of enzyme from heart to plasma was studied in two experimental models. First, the enzyme alanine aminotransferase was slowly infused into the left ventricular wall in open-chest dogs. The half-life for the washout of alanine aminotransferase activity into plasma was 20 +/- 4 minutes (mean +/- SEM, n = 8) and was not different in ischemic and normally perfused tissue. From measurements of arteriovenous differences in alanine aminotransferase activity and left ventricular blood flow, it was concluded that 77 +/- 14% of total enzyme washout from ischemic tissue occurred by direct entry into the bloodstream. The corresponding value for the vascular permeability-surface area product was 264 +/- 55 ml.kg-1.hr-1. For a second model, we studied myocardial enzyme release into plasma after abrupt heart injury induced by 10 minutes of calcium-free coronary perfusion followed by reintroduction of calcium (calcium-paradox mechanism). The half-life for the release into plasma was 1.9 +/- 0.2 hours (mean +/- SEM, n = 6) and was again not influenced by sustained ischemia. Slower washout, as observed for this second model, is consistent with increased interstitial protein space and corresponds to a permeability--surface area product between 135 and 285 ml.kg-1.hr-1. These results were used to calculate the time course of cellular enzyme leakage from the rate of enzyme release into plasma in various forms of heart injury. Significant shifts between the time curves of evolving cellular injury and enzyme release into plasma are observed after 2 hours of ischemia followed by coronary reperfusion, but not after permanent ischemia.
Use of plasmid profiles in the investigation of a patient with Helicobacter pylori infection and peptic ulcer disease. Plasmids may effect bacterial virulence and antibiotic resistance, and serve as epidemiologic markers. In this study, plasmid DNA profiles of serial isolates of Helicobacter pylori showed persistence of an identical strain of this organism in a patient with duodenal ulcer disease. Three control strains of H. pylori isolated from other patients contained plasmids different from each other and from that of the original patient; two of these strains had two plasmids each. These data have important implications for further study of the epidemiology and pathogenesis of H. pylori-related diseases.
Vigabatrin: rational treatment for chronic epilepsy. Vigabatrin is a selective, irreversible suicide inhibitor of GABA transaminase and thus increases brain and CSF GABA. In 33 adult patients with long standing refractory epilepsy on treatment with one or two standard anti-convulsant drugs, the addition of vigabatrin up to 3g daily for eight weeks was associated with a 48.2% reduction in seizure frequency. Twenty patients who had exhibited a 50% or more reduction in frequency of one or more seizure types entered an eight week double-blind placebo controlled phase. Patients on vigabatrin maintained a 54.7% reduction of seizure frequency, whereas those on placebo showed an 18.6% increase in seizure frequency, a highly significant difference between the two groups. In the open phase, seven patients were withdrawn due to unacceptable and reversible adverse events. The commonest side effects were drowsiness, depression and mood instability, and headaches. Vigabatrin is a potentially valuable new treatment for chronic epilepsy, especially partial seizures with or without secondary generalisation.
Diagnosis of Campylobacter pylori gastritis. Campylobacter pylori is a bacterium that inhabits gastric mucosa. It causes chronic active gastritis and is highly associated with duodenal ulcer. Campylobacter pylori has a urease enzyme (not present in man), which allows diagnosis by a [14C]urea breath test. We compared two noninvasive tests, the breath test and serum ELISA, to biopsy and histologic diagnosis. Twenty-two patients who underwent gastroduodenoscopy for evaluation of possible peptic ulcer disease entered the study. The breath test detected the organism in eight of eight patients biopsy-positive for the organism (sensitivity 100%). The breath test was negative in 12 of the 14 patients who were biopsy-negative (specificity 86%). The ELISA was performed in 14 patients. It was positive in 5 of 5 patients biopsy-positive for the organism (sensitivity 100%) and negative in 7 of 9 patients who were biopsy-negative (specificity 78%). We conclude that both the ELISA and the [14C]urea breath test are excellent noninvasive methods to detect Campylobacter pylori. However, only the breath test is suitable for following the response to treatment, as it detects the presence of the organism rather than an immune response to it.
Prospective study of estrogen replacement therapy and risk of breast cancer in postmenopausal women [published erratum appears in JAMA 1991 Apr 10;265(14):1828] We prospectively examined the use of estrogen replacement therapy in relation to breast cancer incidence in a cohort of women 30 to 55 years of age in 1976. During 367 187 person-years of follow-up among postmenopausal women, 722 incident cases of breast cancer were documented. Overall, past users of replacement estrogen were not at increased risk (relative risk, 0.98; 95% confidence interval, 0.81 to 1.18), including even those with more than 10 years since last [corrected] use (relative risk after adjustment for established risk factors, 0.70; 95% confidence interval, 0.45 to 1.10). However, the risk of breast cancer was significantly elevated among current users (relative risk, 1.36; 95% confidence interval, 1.11 to 1.67). Among current users, a stronger relationship was observed with increasing age but not with increasing duration of use. These data suggest that long-term past use of estrogen replacement therapy is not related to risk of breast cancer but that current use may modestly increase risk.
Study of neu-protein expression in mammary Paget's disease with and without underlying breast carcinoma and in extramammary Paget's disease. Correlation between neu/c-erbB-2/Her-2 gene amplification and overexpression of the neu gene product has been reported in tumors of glandular origin, especially ductal breast carcinomas. Formalin-fixed and dewaxed sections from 23 cases of mammary (MPD) and 9 cases of extramammary (EPD) Paget's disease were immunohistochemically stained by means of the monoclonal antibody 3B5 directed against an intracellular domain of the neu gene protein. All MPDs exhibited a distinct membrane staining of tumor cells independent of the presence of ductal breast carcinomas found in 18 cases. All these breast carcinomas also were positive for neu staining. In contrast to MPD, all EPDs were negative. Normal epidermis was always negative. Northern blot analysis sustained the immunohistologic findings in that the presence of neu mRNA could be demonstrated in two of three cases with MPD. Negativity in one case was due to dilution effects by nontumor cells. Our results suggest that Paget cells of mammary and extramammary localization, although very similar phenotypically, derive from different genetic accidents. Furthermore neu positivity in all MPDs and all underlying ductal carcinomas suggests common genetic alterations for both tumors. However the finding of five neu protein-positive MPDs without associated ductal breast carcinomas may suggest a somewhat different transformation process.
Outpatient health care utilization of patients with inflammatory bowel disease. On the basis of the normal life expectancy of inflammatory bowel disease patients, the early onset of their disease, and the variety of symptoms, inflammatory bowel disease patients were anticipated to be frequent users of outpatients services. This study assesses (1) the characteristics, (2) outpatient health care utilization, and (3) the degree of satisfaction with health care of inflammatory bowel disease patients compared to patients with other gastrointestinal disease. The study method was a secondary analysis of data collected on 395 patients attending the University of Calgary Gastroenterology Outpatient Clinic in 1988. Inflammatory bowel disease patients were significantly younger (P less than 0.001) and better educated (P less than 0.05) than other patients. During the past year inflammatory bowel disease patients consulted significantly more often with their gastroenterologist (P less than 0.001) and spent more time in hospital (P less than 0.05) than other patients. Inflammatory bowel disease patients also consulted more frequently with herbalists and naturopaths. Lastly, inflammatory bowel disease patients were as satisfied with the health care they received as other patients. These results provide information useful for health care planners as well as for those dealing directly with inflammatory bowel disease patients.
Hypertension after operative correction of club-foot deformity. Severe hypertension occurred as a postoperative complication after correction of a club-foot deformity in four children (seven feet) who were between the ages of two and three years and had no history of hypertension. The hypertension subsided slowly after administration of antihypertensive medications or more rapidly after release of the correction that had been obtained operatively.
Role of cell-mediated immunity to staphylococci in blepharitis. We studied cell-mediated immunity to staphylococcal antigens in 116 patients with chronic blepharitis and eight normal subjects. Antibodies in tears and blood were measured. Enhanced cell-mediated immunity to Staphylococcus aureus was demonstrated in 46 of 116 patients (40%) in the absence of antibodies to teichoic acid but not among normal subjects. Symptoms of grittiness and morning stickiness were more frequent among patients without enhanced responses. Folliculitis occurred more commonly among patients with enhanced immunity. Marginal keratitis occurred equally among patients with and without enhanced systemic immunity, but patients with enhanced response more commonly required topical corticosteroid therapy. Desensitization to staphylococcal antigens could be investigated as a potential therapeutic approach in selected patients.
Adverse haemodynamic effects of high-dose aprotinin in a paediatric cardiac surgical patient. High-dose aprotinin for reduction of intra- and postoperative blood loss was associated with profound hypotension and flushing in a 3.5-year-old child who underwent cardiac surgery. Treatment with noradrenaline and intravenous fluid was required. Cardiovascular stability was restored after 10 minutes.
Induction of DNA fragmentation in chronic B-lymphocytic leukemia cells. Chronic lymphocytic leukemia of B cell type (B-CLL) is a neoplastic disorder characterized by the accumulation of small resting lymphocytes in the periphery. The phenotype of these cells suggests that they are "frozen" at an early stage of maturation. Glucocorticoid hormones are commonly used to treat patients with B-CLL, resulting in a reduction in the peripheral lymphocyte count by an undefined mechanism. Here we report that glucocorticoids stimulate DNA fragmentation characteristic of a suicide process known as apoptosis or programmed cell death (PCD) in suspensions of cells from patients with B-CLL. The effects can be mimicked by Ca2+ ionophore and involve a sustained increase in the cytosolic Ca2+ concentration. Specific antibodies binding to membrane-associated IgM on the leukemic cells can also induce PCD by a similar mechanism. Phorbol esters block DNA fragmentation and cell killing in response to all of the agents, suggesting that activation of protein kinase C desensitizes the cells to PCD. Targeting the B-CLL cells with antibodies that induce an unbalanced, sustained Ca2+ increase may therefore represent a rational strategy for the destruction of leukemic cells.
Upward shift of the lower range of coronary flow autoregulation in hypertensive patients with hypertrophy of the left ventricle BACKGROUND. At any given perfusion pressure, coronary reserve is expressed by the difference between autoregulated and maximally vasodilated flow. In hypertension the raised coronary resistance reduces the steepness of the pressure-flow relationship at maximal vasodilatation. In the presence of cardiac hypertrophy the line of autoregulated flow becomes higher. For these reasons coronary reserve is reduced and the point at which baseline flow approaches the maximal achievable flow might be shifted to a higher perfusion pressure. Thus, any reduction below this elevated and critical value of pressure would lower the coronary flow. METHODS AND RESULTS. The investigated patients were normotensive (controls, nine) and hypertensive with normal (group I, seven) or augmented LV mass index because of concentric LV hypertrophy (group II, eight). All had effort-induced angina and angiographically normal left epicardial branches. Flow in the great cardiac vein was measured by thermodilution in the baseline and during stepwise (5 mm Hg every 5 minutes) decrease of the coronary perfusion pressure with a titrated nitroprusside i.v. infusion; perfusion pressures of 60 mm Hg in the controls and 70 mm Hg in the hypertensives were taken as end points. Baseline flow averaged 102 ml/min in normotensives, 104 ml/min in hypertensive group I and 148 ml/min in hypertensive group II. At the end points flow was similar to baseline in the controls and group I. In group II coronary flow started to decline and myocardial O2 extraction started to slightly but significantly rise at perfusion pressures of 90-80 mm Hg; at the end point flow was reduced by 26% (p less than 0.01 from baseline). The perfusion patterns did not seem to be related to the changes in tension-time index and heart rate. CONCLUSIONS. The association of high blood pressure (reduced ability of the coronary arterioles to dilate) and hypertrophy of the myocardium (augmented baseline coronary flow) may shift the point of exhaustion of coronary reserve to a higher perfusion pressure and make the myocardium vulnerable to treatment-induced relative hypertension.