123rc/medical_text huggingface dataset:
Effect of nifedipine on total ischemic activity and circadian distribution of myocardial ischemic episodes in angina pectoris. A randomized, double-blind, crossover study was conducted in 10 patients to assess the effect of nifedipine versus placebo on total ischemic activity and circadian distribution of ischemic episodes. After baseline exercise treadmill testing and 48-hour ambulatory electrocardiographic ST-segment monitoring, patients received either nifedipine (mean dose, 80 mg/day) or placebo administered 4 times per day, with the initial dose taken immediately upon arising in the morning. Patients were maintained on a stable dose of each study drug for 7 days, after which they underwent repeat exercise treadmill testing and 48-hour ambulatory electrocardiography. During exercise treadmill testing, greater exercise duration was achieved by patients receiving nifedipine than by those receiving placebo (421 +/- 121 vs 353 +/- 155 seconds, respectively; p less than 0.05). Time to greater than or equal to 1 mm ST depression was significantly greater with nifedipine (282 +/- 146 seconds) than at baseline (130 +/- 72 seconds, p less than 0.003) and with placebo (150 +/- 98 seconds, p less than 0.0005). During ambulatory electrocardiographic monitoring, nifedipine reduced both the total number of ischemic episodes (18 vs 54 at baseline and 63 with placebo; p less than 0.02 for both) and the total duration of ischemia (260 vs 874 at baseline and 927 minutes with placebo; p less than 0.02 for both). The surge of ischemia between 06:00 and 12:00 noted at baseline and during placebo therapy was nearly abolished during nifedipine treatment. Nifedipine at this dosage, administered in this manner, is effective in reducing total ischemic activity and may prevent morning surges of ischemic episodes.
Inhibition by dexamethasone of histamine production in allergic inflammation in rats. In an allergic inflammation model of air pouch type in rats, histamine level in the pouch fluid and histidine decarboxylase activity of pouch wall tissues in the postanaphylaxis phase were increased. Although treatment with dexamethasone failed to inhibit histamine release from mast cells in the anaphylaxis phase, histamine production in the postanaphylaxis phase was inhibited dose dependently. Histamine production-increasing activity in the pouch fluid collected 8 h after the Ag challenge, which was estimated by an activity to stimulate histamine production by bone marrow cells, was decreased by the administration of dexamethasone at the time of the Ag challenge. The addition of steroidal antiinflammatory drugs, dexamethasone, prednisolone, or hydrocortisone, into the incubation medium inhibited the pouch fluid-induced histamine production by bone marrow cells. Hydrocortisone mesylate antagonized the inhibitory effect of dexamethasone on histamine production by bone marrow cells. However, hydrocortisone mesylate failed to recover the decrease in histamine production-increasing activity of the pouch fluid collected from dexamethasone-treated rats. In addition, the dialyzed sample of pouch fluid obtained from dexamethasone-treated nonsensitized rats did not reduce the stimulated histamine production by the pouch fluid sample obtained from the sensitized rats. However, increase in histamine production of bone marrow cells stimulated by the pouch fluid was not inhibited by cyclosporin A that inhibited histamine production induced by Con A. This observation indicates that the pouch fluid has no effect to induce production of the histamine production-increasing factor by bone marrow cells. Consequently, it is suggested that dexamethasone inhibits not only the production of histamine production-increasing factor but also the response of histamine-producing cells to this factor.
New angiotensin converting enzyme inhibitors. Their role in the management of hypertension. The introduction of orally active angiotensin converting enzyme (ACE) inhibitors has revolutionized the treatment of hypertensive disorders and provided an effective alternative for the management of congestive heart failure (CHF). By interfering with the formation of angiotensin II, the active agent of the renin system, ACE inhibitors block the system's vasoconstrictive and sodium-retaining effects, with a consequent reduction in systemic blood pressure. The net effect is improved blood flow and reduced cardiac work. Thus, ACE inhibitors are likely to improve cardiac work capacity and quality of life. Their mechanism of action differs markedly from that of traditional antihypertensive agents which lower blood pressure while reducing cardiac output and blood flow. Since the primary action of ACE inhibitors is to block the renin system, a dramatic response to monotherapy suggests a large renin factor while the lack of a response suggests a low-renin state more amenable to treatment with a diuretic or calcium antagonist. Because of their many attributes, ACE inhibitors are increasingly used as first-line therapy for the treatment of hypertension or CHF. The prototype orally active ACE inhibitor, captopril, is a sulfhydryl compound with a good safety profile at the recommended dosages but reported toxicity at higher dosages. Second-generation ACE inhibitors (eg, enalapril and quinapril) are more potent sulfhydryl-free esters with a greater affinity for the converting enzyme. These newer agents are pro-drugs requiring ester hydrolysis to form the active free acid compound.
Left and right ventricular flows by Doppler echocardiography: serial measurements in patients with aortic regurgitation during exercise, cold pressor stimulation, and vasodilation. To test the practicality of Doppler echocardiography to measure serial change, biventricular outputs were measured in 15 patients with aortic regurgitation during control periods and during interventions of bicycle exercise, cold pressor stimulation, and vasodilation. Biventricular stroke volumes were measured in 10 normal subjects for validation of methods and differed by 2.8%. Reading errors were 3.7%. Signal quality improved between the first and last observation (p less than 0.05). Velocity signals were corrected for intercept angles, which averaged 12 and 19 degrees for right heart flows and 31 and 32 degrees for the left side of the heart in all subjects. Negative correlations occurred between intercept angles and the chronologic order in which the patients were studied for left (p = 0.02) and right (p = 0.05) flows. Mean flow areas varied 9% in the left ventricle and 20% in the right ventricle. Total variability for measuring flow determined from control values was 11% to 13%. When twice the variability was used as the detectable level of change, only exercise provoked real increases in biventricular flows in the majority of patients. We conclude that serial measurements of flow by Doppler echocardiographic methods had to exceed 20% to 25% to achieve significant change. Measuring intercept angle, resolving flow area, and learning are variables that need greater emphasis.
Psychometric and descriptive perspectives of illness impact over the life span. This article describes the development of an instrument that quantifies illness over the course of life. The sample was comprised of 308 women, aged 50 to 70, who were alumnae of a master's program in nursing. Each submitted information concerning illness experienced during each decade of life. Each time period was then rated multidimensionally (Duration, Discomfort, Interference, Threat to Life) to reflect the impact of the various conditions and the means by decade (Decade Impact) were computed. In general, after the first two decades, magnitude of ratings increased with age, indicating greater disease impact. Interrater reliability and internal consistency reliability of the scale were high. Evidence for construct validity included substantial differences between those with and without specific illness conditions, as well as correlations with hospitalization history and health self-ratings. In cluster analysis of patterns across decades, five distinct patterns emerged into which subjects were grouped.
Mechanism of fibrous capsule formation surrounding hepatocellular carcinoma. Immunohistochemical study. In 14 cases of hepatocellular carcinoma with capsule, we studied the mechanism of capsule formation by the immunoperoxidase technique using antibodies to types I, III, and IV collagen, antilaminin antibody, and anti-prolyl hydroxylase antibody. Marked round cell infiltration was observed in the noncancerous side of the capsule and around compressed hepatocytes near the capsule. Thin capsules were composed primarily of type III collagen produced by an increased number of fibroblasts, transitional Ito cells, and hepatocytes near the capsule. In thickened capsules, the noncancerous side consisted primarily of type III collagen and the cancerous side of types I and III collagen. Type I as well as type III collagen was produced by fibroblasts, transitional Ito cells, and hepatocytes. The capsule thus formed is suggested to be part of the defense mechanisms against the growth of hepatocellular carcinoma.
Left ventricular end-systolic stress-volume index ratio in aortic and mitral regurgitation with normal ejection fraction. To evaluate the left ventricular contractile state in regurgitant valvular disease with normal ejection fraction, we analyzed the end-systolic stress-volume index relationship (ESSVR) by means of cineangiography in 15 normal subjects, 11 patients with aortic regurgitation (AR), and 10 patients with mitral regurgitation (MR) whose ejection fraction (EF) was 60% or more. The end-systolic stress-volume index ratio in normal subjects was 5.57 +/- 0.60 kdyne/cm5/m2 (mean +/- standard deviation), and we defined the range including +/- 2 standard deviations of the ratio as the normal ESSVR range. Six patients with AR and five patients with MR placed inside the normal ESSVR range, termed AR IN and MR IN, but the remaining five patients with AR and MR placed to the right of the normal range, termed AR OUT and MR OUT. EF did not differ between patients with AR IN and AR OUT (69.4 +/- 5.4 verus 70.7 +/- 6.1%) and between MR IN and MR OUT (71.6 +/- 3.6 versus 71.1 +/- 7.9%). The EF of the subdivided groups with AR and MR also did not differ from that of normal subjects (70.7 +/- 7.3%). This finding showed that the left ventricular contractile state was depressed in patients with AR OUT and MR OUT despite a normal EF. In AR and MR the end-systolic stress and end-systolic volume index of OUT did not differ from those of IN, but the end-diastolic volume index of OUT was larger than that of IN (AR OUT 156.8 +/- 27.9 versus AR IN 110.8 +/- 24.1 ml/m2, MR OUT 160.5 +/- 44.7 versus MR IN 101.0 +/ 16.6 ml/m2; both p less than 0.05), and the regurgitant fraction of OUT was higher than that of IN (AR OUT 52.6 +/- 13.6 versus AR IN 29.7 +/- 13.3%, MR OUT 52.9 +/- 10.2 versus MR IN 30.2 +/- 11.4%; both p less than 0.05). In addition, there was a linear inverse correlation between the end-systolic stress-volume index ratio and the end-diastolic volume index in all subjects (r = -0.82, n = 36). In normal subjects there was a linear inverse correlation between end-systolic stress and the EF (r = -0.91, n = 15), but this relationship failed to separate patients with OUT from those with IN. Results of the present study suggest that some patients with AR and MR whose EF was normal had a depressed contractile state, and these patients had a large end-diastolic volume index and a high regurgitant fraction.(ABSTRACT TRUNCATED AT 400 WORDS).
Cytomegalovirus in a macerated second trimester fetus: persistent viral inclusions on light and electron microscopy. The macerated stillborn fetus represents at least one third of all perinatal deaths. Microscopic examination of these specimens is often unrewarding. We have reported a clinically unsuspected cytomegalovirus infection in a second trimester macerated fetus. Cells suggestive of CMV inclusions were identified by light microscopy, but electron microscopy confirmed the presence of viral infection and proved valuable in making the diagnosis even though necrosis was severe.
Superficial bladder cancer in patients under 40 years of age. Efficacy of topical prophylaxis. In patients under the age of 40 years with primary superficial bladder cancer the efficacy of adjuvant topical treatment was the same as in elderly patients (recurrences 23%, progression rate 8%). Patients should therefore be treated on the basis of stage and grade of the tumour regardless of their age.
Risk stratification in survivors of acute myocardial infarction: routine cardiac catheterization and angiography is a reasonable approach in most patients [editorial] Noninvasive risk assessment in survivors of AMI can effectively subdivide patients into groups with differing risk profiles after hospital discharge, but some patients at risk for late death or recurrent AMI may be incorrectly identified; data from cardiac catheterization and angiography provide complementary and generally more powerful prognostic information. Many patients may derive particular benefit from early cardiac catheterization and angiography, including: (1) patients with AMI complicated by recurrent myocardial ischemia, congestive heart failure, and/or complex ventricular arrhythmias; (2) patients with abnormal or inconclusive results of noninvasive testing or those patients unable to perform an exercise test; (3) patients with abnormal left ventricular global systolic function and those with increased left ventricular end-systolic volume; (4) "young" patients (younger than 50 years of age?); (5) older patients (older than 65 to 70 years of age?); (6) patients with non-Q wave AMI; and (7) patients who are receiving thrombolytic therapy. Performance of early cardiac catheterization and angiography in virtually all survivors of AMI, with selective use of appropriate noninvasive tests, may provide a more efficacious means of risk assessment after AMI; if all tests are performed judiciously, the cost of such an approach need not be excessive. A combination of invasive and selected noninvasive tests probably provides optimal information. The risks to the routine performance of diagnostic cardiac catheterization and angiography in all survivors of AMI are: (1) adequate care and attention may not be paid to proper performance of the procedure(s) and to detailed and proper analyses of the data; (2) the need for additional noninvasive testing in selected patients may be ignored; and most importantly, (3) premature or unnecessary revascularization procedures may be performed subsequently. For optimal patient care, the clinician must obtain all necessary data, avoid unnecessary and repetitive tests, know the accuracy of individual tests at his or her own facility, interpret all data in proper context, and then counsel patients objectively about available management strategies. With this approach, all patients who might appropriately benefit from coronary artery revascularization will be correctly identified, and patients who are truly at very low risk (minimal residual coronary artery disease and preserved left ventricular function particularly if associated with a patent infarct-related artery) may be similarly identified and managed appropriately with elimination of unnecessary additional testing and pharmacologic therapy. Finally, whatever approach to risk stratification one chooses for an individual patient, the importance of and the need to correct and/or ameliorate risk factors for coronary artery disease must be recognized and undertaken.
Nuclear grading of breast carcinoma by image analysis. Classification by multivariate and neural network analysis. The use of nuclear grade as a prognostic indicator for breast carcinoma has been limited by interobserver variability. Advances in image analysis and automated cell classification offer one approach to this problem. The authors used the CAS-100 (Cell Analysis System. Elmhurst, IL) system to measure and analyze nuclear morphometric and texture features of cytologic preparations from 35 breast carcinomas (well, moderate, and poorly differentiated) as well as benign lesions. Morphometric and Markovian texture feature data from breast cancer nuclei of various grades comprised a training set, which was then used to establish classification criteria by multivariate (Bayesian) analysis and to train a neural network system. Both systems were tested for the ability to classify the nuclear grade of individual nuclei. There was good agreement between computer classification and the grade assigned by human observer to individual nuclei using either Bayesian or neural network analysis. Thirty-one unknown cases, which were assigned an overall grade by an observer, were then analyzed by computer, and an overall grade assigned based on the grade of nucleus most frequently present. Using this method, both classification systems were able to assign a "correct" grade to low-grade lesions (approximately 70% correct) more often than to high-grade tumors (approximately 20%). Difficulty in computer assignment of high-grade tumors was explained by nuclear heterogeneity in these tumors (i.e., although the percentage of high-grade nuclei was increased compared with that of low-grade tumors, high-grade nuclei frequently did not predominate). The authors present this study to demonstrate the feasibility of using image analysis as an objective means of nuclear grading. Further studies will be needed to establish criteria for assigning overall nuclear grade based on computer analysis of imaging data.
Penetrating keratoplasty for keratoconus: complications and long-term success. A series of 100 penetrating keratoplasties for keratoconus performed between 1968 abd 1986 were reviewed for long-term results. The mean follow-up was 6.1 years with a range of 4-16 years. The systemic associations and the postoperative complications were analysed. Grafting in cases associated with Down's syndrome had a higher incidence of complications. 93% of grafts remained clear and 81% achieved a final corrected visual acuity of 6/12 or better. 21% of eyes developed a homograft reaction, with 50% of rejection episodes occurring in the first year after operation. Factors associated with higher incidence of rejection included loose sutures, traumatic wound dehiscence, and grafts larger than 8.5 mm. Only three grafts with rejection episodes lost graft clarity, while rejection in the rest was successfully reversed with topical steroid therapy. No relationship was found between donor age and long-term graft clarity.
Cardiopulmonary assessment in beta-thalassemia major. Thalassemia patients succumb at a young age to congestive heart failure. Hitherto, attention has been focused on left ventricular function. This report emphasizes right ventricular dysfunction and abnormal pulmonary function. We performed cardiopulmonary evaluation, including echo-Doppler, spirometry, CO diffusion (DCO), and blood gas analyses in 35 patients with homozygous beta-thalassemia maintained by multiple blood transfusions. Six autopsy lung specimens were studied. Thalassemia patients exhibited pulmonary dysfunction, characterized by hypoxemia (85 percent of the patients were outside the 95 percent confidence limits), reduced lung volumes (51 percent), flow rates (63 percent) and DCO (50 percent). Right ventricular dysfunction was more prevalent than left ventricular dysfunction. Furthermore, 75 percent of the patients had evidence of pulmonary hypertension consistent with more frequent right ventricular rather than left ventricular dysfunction. Our findings suggest that in thalassemia patients, complex cardiopulmonary abnormalities precede the final outcome of congestive heart failure.
Significance of surgical adjuvant chemotherapy for gastric cancer. One hundred and twenty-four specimens (72 primaries and 52 metastases) in 107 patients with gastric cancer were tested using the human tumor clonogenic assay (HTCA). Assays for 64 specimens (52%, 33 primaries and 31 metastases) were considered evaluable. The clonogenicity of the primaries was less than that of the metastases (P less than 0.01). In the primary specimens, well-differentiated tumors were more highly clonogenic than poorly differentiated or signet ring cell tumors (P less than 0.05). Viable malignant cells and clonogenic cells were abundant in the primary tumors with mucosal (m) and submucosal (sm) invasion, i.e., in early gastric cancers by Japanese criteria, and were reduced in numbers as the primary tumors advanced (P less than 0.05). In vitro chemosensitivity corresponded well to the clonogenicity of the primary tumors stratified by the degree of tumor invasion. At the early phase of primary tumor progression and metastasis, clonogenicity and chemosensitivity were high. Aggressive chemotherapy with sensitive drugs after surgery may improve the clinical results for the gastric cancer patients with early phase of metastases.
The predictive value of needle localization mammographically assisted biopsy of the breast. This study was done to review critically the experience at the University of California at San Diego in needle localization mammographic biopsy of the breast with regard to use and accuracy in identifying early carcinoma of the breast. Ninety-seven patients underwent needle localization mammographic biopsy of the breast between 1985 and 1987. Indications for this procedure included the presence of microcalcifications or a mass shown on mammographic examination, or both, in conjunction with physical examination which did not define a discrete abnormality in the area. Mammographic, demographic, pathologic, hormone receptor data and staging information were recorded and processed on the MicroVax II computer (Digital Equipment Corporation). Twenty-four per cent of lesions with needle localization mammographic assisted biopsy proved to be malignant. Sixteen lesions were diagnosed as an infiltrating ductal carcinoma and ten of these had an accompanying intraductal carcinoma. Over-all, intraductal carcinoma was present in 16 of the 23 specimens diagnosed as malignant. At biopsy, the margins were clear in 17 of 23, and vascular invasion was present in only one patient with an infiltrating lobular carcinoma. Five were tumor in situ, 12 were stage 1 and five were stage 2 (staging information was not available in one instance). Hormone receptor data were available in 17 of 23 specimens. Estrogen receptors were positive in 13 and progesterone receptors were positive in six. The smallest preinvasive malignant lesion was 4 millimeters, as seen on the mammogram, and the smallest free-standing invasive lesion was 8 millimeters. Preinvasive lesions (intraductal) presented as microcalcifications in 80 per cent. Invasive lesions presented as either a mass (n = 9) or as a mass and microcalcifications (n = 5) in 81 per cent. All five lesions presenting as both a mass and microcalcifications on mammogram proved to be malignant. Multifocal lesions on mammographic examination which proved to be malignant were multifocal pathologically in only 50 per cent. Needle localization mammographic biopsy is useful in detecting early carcinoma of the breast. Biopsy should be done on lesions presenting on mammogram as both a mass and microcalcifications and not observed. Focality of lesions on mammogram does not correlate with focality on biopsy and may be misleading as criteria for operative planning.