123rc/medical_text huggingface dataset:
Deposits of crystalline material containing silicon in surgically excised human valves. Ninety-seven surgically excised natural cardiac valves were examined by scanning electron microscopy and x-ray energy spectroscopy to assess the occurrence of crystalline deposits that contain the element silicon. Valves examined included 33 mitral valves, 63 aortic valves, and 1 tricuspid valve. To reduce the possibility of surface contamination, the deep layers of some valves were examined after exposure by fracture of the valve. Crystalline material containing silicon was observed in the deep tissue. Such crystalline material was sometimes entwined within subendothelial fibers. Crystalline deposits that contained silicon were associated with 34 of 97 of these valves (35%). Among the 34 valves that showed silicon, 24 (71%) also showed microdeposits of calcific material. In view of evidence that silicon may participate in the calcification of bone, and is found in the intima of arteries, a role for this element in ectopic calcification of valves may exist.
Conjugal temporal arteritis. We report the simultaneous occurrence of biopsy-proven temporal arteritis in husband and wife. Serologic and viral studies were negative, including viral culture of the wife's temporal artery. The concurrent incidence of giant cell arteritis in a married couple would suggest a common exogenous exposure.
Differential regulation of human immunodeficiency viruses (HIVs): a specific regulatory element in HIV-2 responds to stimulation of the T-cell antigen receptor. The human immunodeficiency viruses (HIVs) types 1 and 2 have similar genetic organization but differ significantly in nucleic acid sequence. Although infection by either agent leads to symptoms of immunodeficiency, recent studies suggest potential differences in the time course and severity of these diseases. In this report, the transcriptional regulation and induction of these retroviruses were analyzed. We report that the regulation of HIV-2 differs from that of HIV-1: a distinct T-cell activation pathway, triggering of the CD3 component of the T-cell receptor complex, stimulates HIV-2 but not HIV-1 gene expression. The response to T-cell receptor stimulation in HIV-2 is mediated partly by an upstream regulatory element, termed CD3R, which is recognized by a sequence-specific DNA binding protein, NF-CD3R. Jurkat T leukemia cell lines containing HIV-2 provirus also showed increased viral replication after stimulation of the T-cell receptor complex, in contrast to HIV-1. These findings suggest that transcriptional regulation and induction of HIV-2 differ from HIV-1 and raise the possibility that different cofactors contribute to the activation of HIV-1- and HIV-2-associated AIDS.
Retrovirus from human T-cell leukemia virus type I-associated myelopathy is the same strain as a prototype human T-cell leukemia virus type I. A retrovirus was isolated from a T-cell line that was established from lymphocytes in the cerebrospinal fluid of a patient with human T-cell leukemia virus type I-associated myelopathy (HAM), and its genome was sequenced. The nucleotide sequence of the 3' half of the total genome was identical in 99.5% of the nucleotides to that of the prototype human T-cell leukemia virus type I that was derived from a patient with adult T-cell leukemia. These results indicate that the same retrovirus human T-cell leukemia virus type I is associated with both a neurological disease, HAM, and a lymphoproliferative disease, adult T-cell leukemia.
Diagnostic value of a new myocardial perfusion agent, teboroxime (SO 30,217), utilizing a rapid planar imaging protocol: preliminary results [corrected and republished with original paging, article originally printed in J Am Coll Cardiol 1990 Oct;16(4):855-61] Technetium-99m-labeled agents have advantages over thallium-201 in terms of photon statistics, cost and clinical availability. They have been suggested as an alternative to thallium for myocardial perfusion imaging. Teboroxime is a new boronic acid adduct of technetium dioxime (BATO) compound that demonstrates favorable characteristics in preliminary studies. With use of a novel (seated) patient positioning technique and a rapid dynamic acquisition protocol, 30 patients underwent planar imaging with teboroxoime while at rest and after maximal treadmill exercise. Postexercise scans were completed in an average time (mean +/- SD) of 4.4 +/- 1.6 min, with 4.8 +/- 1.5 min for the views at rest. These results were compared with coronary arteriography or thallium scintigraphy after treadmill exercise, or both. Diagnostic agreement (abnormal versus normal) was present in 28 of the 30 patients (p less than 0.001). Regarding physiologic assessment as compared with thallium scintigraphy, the finding of infarction and ischemia was concordant in 89% and 86% of patients, respectively. This report describes the initial use of teboroxime with a rapid dynamic planar imaging technique, resulting in a high correlation with exercise thallium scintigraphy. Delayed postexercise images obtained 5 to 10 min after exercise demonstrated rapid disappearance of exercise-induced defects noted on the initial (0 to 5 min) postexercise views. The rapid differential washout with teboroxime has not been previously described and the possible clinical significance is discussed.
Osteosarcoma of the spermatic cord. Malignant tumors of the spermatic cord are rare but the vast majority of these tumors are sarcomas. We report on a patient with osteosarcoma arising in the spermatic cord. Left radical orchiectomy with high dissection of the spermatic cord was performed, and the patient remains free of recurrence 2 years postoperatively. We could find no previous discussion or report of this tumor.
Risk of angina pectoris and plasma concentrations of vitamins A, C, and E and carotene The relation between risk of angina pectoris and plasma concentrations of vitamins A, C, and E and carotene was examined in a population case-control study of 110 cases of angina, identified by the Chest Pain Questionnaire, and 394 controls selected from a sample of 6000 men aged 35-54. Plasma concentrations of vitamins C and E and carotene were significantly inversely related to the risk of angina. There was no significant relation with vitamin A. Smoking was a confounding factor. The inverse relation between angina and low plasma carotene disappeared and that with plasma vitamin C was substantially reduced after adjustment for smoking. Vitamin E remained independently and inversely related to the risk of angina after adjustment for age, smoking habit, blood pressure, lipids, and relative weight. The adjusted odds ratio for angina between the lowest and highest quintiles of vitamin E concentrations was 2.68 (95% confidence interval 1.07-6.70; p = 0.02). These findings suggest that some populations with a high incidence of coronary heart disease may benefit from eating diets rich in natural antioxidants, particularly vitamin E.
Urologic function after experimental cauda equina compression. Cystometrograms versus cortical-evoked potentials. Twenty female beagle dogs underwent an L6-7 laminectomy and six dogs each had 25, 50 or 75% constriction of the cauda equina and 2 control dogs had laminectomy only. Cystometrograms were performed pre- and post-operatively and three months after constriction. Cortical evoked potentials were monitored pre- and post-operatively and monthly for three months. After three months of constriction, the cauda equina of these dogs in each group was examined histologically and vascular circulation was examined by latex and India ink injection (Spalteholz technique). The control dogs had normal CMGs and CEPs. Twenty-five percent constriction caused no CMG changes and mild CEP changes. Fifty percent constriction caused no statistically significant CMG changes, major CEP changes and venous congestion of the nerve roots and dorsal root ganglia. Seventy-five percent constriction produced severe CMG changes with detrusor areflexia, increased bladder capacity and clinical incontinence. CEPs also had marked deterioration. Vascular analysis revealed severe arterial narrowing at the level of constriction and venous congestion of the nerve roots and dorsal root ganglia. Blockage of axoplasmic flow and nerve root atrophy was seen in all dogs with 75% constriction. Cortical evoked potentials were the most sensitive predictor of neural compression. CMGs were not sensitive until severe compression was achieved. Bladder dysfunction, i.e., detrusor areflexia, appears to occur with blockage of axoplasmic flow and early sensory changes occur with neurovenous congestion.
Six physicians with inflammatory bowel disease. This essay tells the stories of six physicians with inflammatory bowel disease (IBD) to emphasize how important denial and control become when a physician is a patient. Guilt at the supposed psychosomatic "origin" of IBD suggests that we as physicians should never blame our patients for getting sick.
Intrathecal morphine 0.2 mg versus epidural bupivacaine 0.125% or their combination: effects on parturients. To compare the efficacy and side effects of 0.2 mg intrathecal (IT) morphine with 0.125% epidural bupivacaine, 62 women in labor were studied. They were randomly divided into three groups: group 1 (n = 20) received IT morphine; group 2 (n = 22) received epidural bupivacaine; and group 3 (n = 20) received a combination of both using a combined spinal-epidural (CSE) technique. According to a visual analogue scale for assessing analgesia, neither IT 0.2 mg morphine nor 10 ml 0.125% epidural bupivacaine was effective in producing adequate pain relief in labor, whereas the combination produced excellent analgesia. The use of IT morphine significantly reduced the dosage requirement of epidural bupivacaine. The incidence of nausea, vomiting, and pruritus was significantly higher when IT morphine had been administered, whereas that of urinary retention did not differ. No serious respiratory depression occurred in any of the patients. When the course of labor was studied, the prior use of IT morphine significantly prolonged the duration of the first stage of labor and the total duration of labor. We conclude that the administration of 0.2 mg IT morphine in combination with epidural administration of 0.125% bupivacaine provides better analgesia than the administration of either drug alone.
Modulation of mediator release from human intestinal mast cells by sulfasalazine and 5-aminosalicylic acid. Intestinal mast cells are thought to contribute to the mucosal inflammation in ulcerative colitis and Crohn's disease through release of inflammatory mediators. Since sulfasalazine and its metabolite 5-aminosalicylic acid are effective therapeutic agents in inflammatory bowel disease and have been shown to inhibit generation of inflammatory products in other cells, we examined the effect of these agents in vitro on human intestinal mast cell mediator release. Sulfasalazine (5 x 10(-4)-10(-3) M) was found to significantly enhance goat anti-human IgE-induced histamine release from intestinal mast cells, which is the same response as seen in human blood basophils, whereas its metabolite 5-aminosalicylic acid was an effective inhibitor of stimulated histamine release in both mast cells and basophils. 5-Aminosalicylic acid also inhibited production of prostaglandin D2 by the stimulated intestinal mast cells. Sulfasalazine alone, without immunologic stimulation, did not induce histamine release from mast cells or basophils, but the enhancement of ongoing mast cell activation by sulfasalazine may explain some cases of adverse reactions to the drug. The inhibition of mast cell histamine release and prostaglandin generation by 5-aminosalicylic acid demonstrates a potential therapeutic modality of this agent.
Management of posterior urethral strictures secondary to pelvic fractures in children. Bulboprostatic anastomotic urethroplasty was performed in 20 children with posterior urethral strictures secondary to bony pelvic fractures. The approach was perineal in 4 children and transpubic abdominoperineal in 16, with good postoperative results in 100 and 62.5%, respectively. In some children the urethral disruption occurred within the prostate itself and not at the prostatomembranous junction. In such cases the proximal sphincteric mechanism may be at risk and immediate repair of the injury is advisable. In the case of common prostatomembranous disruption displacement of the urethra may be significant. In such cases a transpubic approach is preferable. If the proximal sphincteric mechanism is deranged, it can be managed at the same time.
Diabetic retinopathy in blacks. Diabetic eye disease, particularly diabetic retinopathy, is the leading cause of new cases of legal blindness in people 20-74 yr of age in the United States. The prevalence and rate of diabetes in this age-group are higher in Blacks than in Whites. The rate of blindness from diabetic eye disease is also higher in Blacks than in Whites. Severe macular edema, the most frequent cause of decreased vision in diabetic retinopathy, appears to be more common in Blacks. Risk factors for developing macular edema include poorly controlled hypertension, hyperglycemia, and duration of disease. The higher prevalence of hypertension in Blacks may contribute to the increased severity of diabetic retinopathy. Further evaluation is necessary to determine the influence of race on the severity of diabetic retinopathy.
Trends in primary breast cancer management. Where are we going? The treatment of cancer during any period has been based not on the whim of a clinician but on the therapeutic consequences of the dominant biologic model of the disease. Until the 1960s, the dominant model of breast cancer was of a disease that spread centrifugally along anatomic pathways, with time being the only determinant of prognosis. An alternative model, that of biologic determinism, posits that the outcomes of treatment are determined by the extent of microscopic dissemination that occurred before the tumor became detectable. This model, too, has flaws, and the author suggests that it is time for a Kuhnian paradigm shift. Breast cancer exhibits a heterogeneity of phenotypes resulting from one or perhaps two mutations. The multiple prognostic variables may be epiphenomena, expressing different degrees of amplification of a limited domain of the genome.
Effects of diltiazem on the functional recovery of the myocardium at organ and cellular level during prolonged hypothermic ischemic cardiac arrest. The effectiveness of diltiazem on the functional recovery of the heart, calcium (Ca++) uptake and binding, Ca++ ATPase of cardiac sarcoplasmic reticulum (SR), and MB fraction of creatine kinase (MBCK) of coronary sinus blood was investigated after one and a half hours of reperfusion following three hours of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegia; and group III, cold crystalloid cardioplegia with diltiazem. There was a decrease in aortic pressures left ventricular pressure development (dp/dt), left ventricular work index (LVWI), total systemic vascular resistance (TSVR), and left ventricular systolic pressure (LVSP) in the sham bypass group. There was a decrease in cardiac index (CI), LVWI, and mean right atrial pressure (mRAP) and an increase in TSVR and pulmonary vascular resistance (PVR) in group II as compared with group I. Although there was a tendency for a decrease in the indices of myocardial contractility in group II, they were not significantly different from those in group I. The indices of myocardial contractility, CI, and LVWI in group III were slightly higher than in group II, but they were not significantly different from each other. The values for calcium uptake by SR in groups II and III were similar but significantly lower than those in group I. Calcium binding in group III was significantly lower than that in group I. Calcium ATPase of SR in the three groups were similar. Although MBCK increased in all the groups, the increases were not significantly different among the three groups. The results of this study indicate that cold crystalloid cardioplegia with diltiazem was not better than cold crystalloid alone in preserving the cardiac contractility and cellular function during prolonged ischemic cardiac arrest. However, the cardiac function in terms of cardiac index was better preserved with diltiazem.
Widespread functional effects of discrete thalamic infarction. In order to investigate functional effects of various thalamic structures on metabolism in remote, morphologically intact cerebral regions, we used positron emission tomography of (18F)-2-fluoro-2-deoxy-D-glucose to study regional cerebral metabolic rates of glucose (rCMRGlu) in 11 patients with chronic unilateral or bilateral infarcts strictly confined to the thalamus. Patients were grouped according to computed tomographic scans showing anterior (three), medial (four), or posterior (four) lesions. Compared with a matched group of 11 healthy subjects (hemispheric CMRGlu 35.2 +/- 3.49 mumol/100 g per minute), glucose metabolism was significantly lower in the hemisphere ipsilateral to the infarction (31.2 +/- 2.97 mumol/100 g per minute). Patients with bilateral infarcts had lower hemispheric CMRGlu (29.9 +/- 2.74 mumol/100 g per minute) than those with unilateral lesions (32.2 +/- 2.97 mumol/100 g per minute). Depending on infarct location within the thalamus, there was differential depression of rCMRGlu, with the largest effects on frontal and occipital areas in medial infarctions. Except for ipsilateral thalamic deactivation, metabolic patterns with anterior thalamic infarcts were close to normal, while posterior infarcts mostly depressed rCMRGlu in the visual and in the inferior limbic cortex. Cerebellar metabolic rates were within normal limits in most cases. These patterns of regional cerebral deactivation may be related to categories of thalamic projections--intrathalamic, to limbic system and basal ganglia, diffuse to most cortical areas, and specific to defined neocortical areas. Even small brain lesions may have widespread functional sequelae, potentially demonstrable by positron emission tomography.
Study on the genesis of the double potential recorded in the high right atrium in atrial flutter and its role in the reentry circuit of atrial flutter. To investigate the genesis of the double potential (DP), which is two separate waves, and its role in the reentry circuit of atrial flutter (AF), we performed overdrive pacing (ODP) from the high right atrium (HRA) in six cases of spontaneous AF in which the DP was recorded in the HRA. In four of the six cases, when the DP was arbitrarily designated D1 and D2, D1 and D2 showed progressive fusion during ODP. In addition, the D1 return cycle, immediately after the termination of ODP, corresponded to the AF cycle, and the D2 return cycle corresponded to the pacing cycle. This may indicate that the DP is caused by the collision of two directional waves. Furthermore, it is suggested that the HRA plays an important role in preventing a possible shortcutting of reentry waves and in stabilizing the reentry circuit of AF.
Effect of propranolol on endothelin-induced increase in cytosolic free calcium. This study was designed to investigate the effect of propranolol on endothelin (ET)-1-induced increase in cytosolic Ca2+ [( CA2+]i) in cultured vascular smooth muscle cells (VSMCs) obtained from rat aorta. Propranolol (0.01 to 1 mmol/L) reduced the changes in the initial transient and the later sustained phase of [Ca2+]i induced by 100 nmol/L ET-1 as well as 10 mmol/L procaine. The inhibitory action of propranolol on the change in [Ca2+]i induced by ET-1 may be involved in one of the mechanisms of propranolol-induced reduction of vasospasms.
Brief intensive chemotherapy for metastatic non-small-cell lung cancer: a phase II study of the weekly CODE regimen. Fifty-three patients, 17 with stage IIIB and 36 with stage IV non-small-cell lung cancer, were given CODE (cisplatin, vincristine, doxorubicin, and etoposide) plus antibiotic prophylaxis and an antiemetic regimen in an intensive chemotherapy program emphasizing weekly treatment and a planned brief duration (9-12 weeks); for 45 of these patients, the CODE program also included antifungal prophylaxis and supportive corticosteroids. Of the total study population, 33 patients (62%) responded to treatment, including five (9%) with complete response. The median survival for the entire group was 42 weeks (55 weeks for those with stage IIIB and 39 weeks for those with stage IV). More than 40% were alive at 1 year. Comparison of granulocyte counts of patients receiving prednisone with those of the subgroup to whom no corticosteroids were given showed less granulocytopenia for those receiving prednisone. Use of prednisone thus allowed improved delivery of myelosuppressive drugs. CODE was halted in nine patients because of disease progression. Although more constitutional side effects are associated with weekly chemotherapy than with standard chemotherapy, only 12 of the remaining 44 patients (27%) failed to receive at least 9 weeks of treatment. Serious toxicity was uncommon: There were no treatment-related deaths and only three episodes of neutropenia with fever. CODE is a novel treatment for non-small-cell lung cancer that this pilot study provided entirely in an outpatient setting over a 9-12 week period with an acceptable incidence of toxicity and a promising level of efficacy. Additional testing and comparison with other regimens or supportive care alone are warranted.
Usefulness of combined propranolol and verapamil for evaluation of surgical ablation of accessory atrioventricular connections in patients without structural heart disease. Successful surgical ablation of atrioventricular (AV) accessory connections may be confirmed during postoperative electrophysiologic testing by the absence of accessory connection conduction in both the anterograde and retrograde directions. Whereas the former may be readily apparent by examination of the surface electrocardiogram during sinus rhythm or atrial pacing, assessment of the latter may be complicated by the frequent presence of enhanced retrograde AV nodal conduction in the postoperative period. Consequently, availability of interventions that selectively affect AV nodal conduction and refractoriness without concomitant effects on accessory connections may be helpful for assessing the success of the surgical procedure. In this study the effects of combined propranolol and verapamil administration on electrophysiologic properties of the AV node and the accessory AV connection were assessed both pre- and postoperatively in 17 patients (12 men and 5 women, mean age 33 years) undergoing surgical ablation of accessory connections. Preoperatively, electrophysiologic characteristics of all but 1 of the accessory AV connections were unaffected by propranolol and verapamil administration. Postoperatively, on the other hand, propranolol and verapamil significantly prolonged both the retrograde AV node effective refractory period (baseline: 272 +/- 34 ms vs after drugs: 384 +/- 70 ms [p less than 0.0001]) and the shortest cycle length maintaining 1:1 ventriculoatrial conduction (baseline: 357 +/- 99 ms vs after drugs: 485 +/- 64 ms [p less than 0.0001]). Late postoperative electrophysiologic evaluation (7 +/- 3 weeks) revealed no evidence of residual accessory AV connection conduction, and all patients remain asymptomatic at 21 +/- 10 months follow-up.