123rc/medical_text huggingface dataset:
Vascular renin and hypertension. Uptake versus synthesis. Conventional radioimmunoassay techniques demonstrated in the aortic wall a renin-like activity which is derived from plasma but has a longer half-life than plasma renin. Blood pressure elevation after renin injection into nephrectomized rats correlates better with aortic renin than with plasma renin. Vascular and other extrarenal tissue can also synthesize renin. Using a ribonuclease protection technique for the detection of renin messenger RNA we have been able to demonstrate that a wide variety of extrarenal tissues contain the renin message. In at least two of these, the brain and the liver, renin messenger RNA levels are unaffected by changes in dietary salt or by changes in systemic blood pressure. Functional studies using isolated human resistance vessels also demonstrate the presence of renin-like activity by a contractile response to added renin substrate. It is suggested that extrarenal tissues therefore contain renin-like activity derived both from uptake and from local synthesis. These systems may be regulated in different ways and may carry out different functions.
Stapling or suturing for anastomoses of the left side of the large intestine. Two hundred and fifty patients undergoing elective surgical treatment involving anastomoses of the left side of the colon or colon and rectum have been studied in a randomized trial in which the EEA (U. S. Surgical Corp.) circular stapler has been compared with single layer sutured anastomoses. Only patients in whom either technique was feasible were included in the analysis. The operative techniques were largely standardized. Patients were studied by means of a limited barium enema on the ninth or tenth postoperative day. The data have been analyzed for leakage rate (clinical and roentgenologic), other complications and degree of experience of the surgeon. Eleven patients were excluded from the analysis because the selected technique could not be carried out; of these, eight were in the stapled group in which it was possible to perform a sutured anastomosis. There were no instances in which it was possible to staple but not possible to suture. The remaining three exclusions were patients in whom either a coloanal anastomosis or a Hartmann procedure was performed. There was no over-all difference in the leakage rate--roentgenologic, clinical or total--between the two groups. However, when analyzed by the surgeon, the clinical leakage rate for surgeons in training was greater for sutured anastomoses than for stapled anastomoses (p = 0.053). Thus, it appears that the benefits of experience are more pronounced for sutured anastomoses but that, in experienced hands, neither technique is superior.
Extensive peripheral retinectomy combined with posterior 360 degrees retinotomy for retinal reattachment in advanced proliferative vitreoretinopathy cases. Posterior 360 degrees retinotomy in conjunction with extensive peripheral retinectomy was necessary for retinal reattachment in 18 eyes. A visual acuity of 20/400 or better was achieved in 22% of the patients; in patients with rubeosis, regression was found in 89%. Of the hypotonus eyes, preoperatively 78% were normotensive postoperatively after removal of anterior proliferative vitreoretinopathy (PVR) covering ciliary epithelium. The major intraoperative complication was hemorrhage, which could be readily controlled. Recurrent retinal detachment (RD) occurred in 39% and reproliferation in 50% of the patients.
Pneumococcal pneumonia in a rat model of cirrhosis: effects of cirrhosis on pulmonary defense mechanisms against Streptococcus pneumoniae. To study alterations in host defense mechanisms that enhance pneumococcal virulence, a model of Streptococcus pneumoniae pneumonia was developed in cirrhotic rats. Cirrhosis, with or without ascites, was produced in rats by intragastric administration of carbon tetrachloride (CCl4). Histopathologic and laboratory studies demonstrated that CCl4-induced cirrhosis was similar to alcoholic cirrhosis in humans. Cirrhotic rats were more susceptible to type 3 pneumococcal pneumonia induced by intratracheal challenge than controls, and the presence of ascites was associated with the lowest LD50. More cirrhotic rats with ascites had bacteremia and elevated levels of circulating capsular antigen after challenge compared with cirrhotic rats without ascites or controls. Pulmonary clearance of pneumococci was markedly reduced in rats with cirrhosis and ascites and was associated with reduced serum complement levels. This model may be useful in further studies of the pathogenesis and therapy of pneumococcal infections in the compromised host.
Latent sensitisation to respiratory syncytial virus during acute bronchiolitis and lung function after recovery. To determine whether latent sensitivity to respiratory syncytial virus antigen(s) occurs after infection, 27 infants with acute bronchiolitis were studied and compared with 15 hospital controls. Blood was collected for whole blood challenge, and histamine release was measured by a high performance liquid chromatography technique with fluorometric detection. There was a significantly greater histamine release to respiratory syncytial virus antigen(s) in those with bronchiolitis than in controls, expressed either in amount (median 154 nmol/l compared with 104 nmol/l) or percentage release (median 20% compared with 3%). There was a significant difference between index and control groups in terms of individual histamine responses. These findings strongly suggest that infants develop latent sensitivity to respiratory syncytial virus antigen(s) during the course of acute bronchiolitis. Serial lung function tests were performed in 15 infants. All infants had abnormalities of lung function at some stage, but the small numbers of subjects precluded comparison between 'sensitised' and 'non-sensitised' infants. Further study is indicated to define the relation of latent sensitisation and subsequent bronchial hyper-responsiveness after respiratory syncytial virus infection in infants.
A 47-kDa human nuclear protein recognized by antikinetochore autoimmune sera is homologous with the protein encoded by RCC1, a gene implicated in onset of chromosome condensation. Several autoimmune sera from patients with Raynaud phenomenon decorated mammalian kinetochores and bound to a 47-kDa protein on immunoblots of nuclear lysates. Antibody affinity-purified from immunoblots of the 47-kDa band recognized kinetochores, but due to crossreaction with an 18-kDa protein, localization remains elusive. We used one of these sera to purify the antigen from HeLa cells synchronized in mitosis as a noncovalent complex with a 25-kDa protein. The antigen was released from DNA by intercalation with 25 mM chloroquine. Ion-exchange chromatography yielded the pure complex with an apparent molecular size of 68 kDa, which was separated into its components by gel filtration in 6 M guanidinium chloride. Upon two-dimensional gel electrophoresis the 47-kDa protein gave two main spots of pI 6.6 and 6.7, respectively. Posttranslational modification is indicated by additional antigenic spots, by lack of a free alpha-amino group, and by chromatographic behavior of peptides on reversed-phase chromatography. The amino acid sequence for 205 residues of the 47-kDa protein has been established. This sequence is highly homologous with the translated reading frame of RCC1, a gene reportedly involved in regulating onset of mammalian chromosome condensation.
Antenatal phenobarbital for the prevention of periventricular and intraventricular hemorrhage: a double-blind, randomized, placebo-controlled, multihospital trial. To determine whether the neuroprotective properties of phenobarbital would alter the incidence and severity of intracranial hemorrhage in premature infants, we randomly assigned 110 women at less than 31 weeks of gestation to receive 10 mg/kg phenobarbital or placebo in a blinded fashion before delivery. Infants were examined postnatally with real-time ultrasonography for evidence of intracranial hemorrhage. Maternal demographics, pregnancy complications, antenatal management, and route of delivery did not differ between the phenobarbital group (n = 50) and the placebo group (n = 60). The total incidence of periventricular-intraventricular hemorrhage did not differ between the phenobarbital-treated (n = 54) and the placebo-treated (n = 67) infants. However, the frequency of grade 3 and grade 4 hemorrhages was 15% (10 infants) in the placebo group and 3.7% (2 infants) in the phenobarbital group (p less than 0.05). There were no differences in the severity of associated conditions in the babies to explain the difference in the incidence of severe hemorrhage between the study groups. We conclude that antenatal administration of phenobarbital appears to be effective in decreasing the severity of periventricular-intraventricular hemorrhage in infants delivered at less than 31 weeks of gestation.
Prediction of outcome in acute pancreatitis: a comparative study of APACHE II, clinical assessment and multiple factor scoring systems. The APACHE II severity of disease classification system has been examined prospectively in 160 patients with acute pancreatitis. Using clinical and simple laboratory data APACHE II was able to provide useful discrimination between uncomplicated, complicated and fatal attacks within a few hours of admission. Peak APACHE II scores (recorded during the first 3 days) had a prognostic accuracy similar to the multiple factor scoring systems, but then incurred a similar delay. Patients could be graded according to their risk of death or of developing a major complication; no deaths occurred in patients with a peak APACHE II score less than 10. APACHE II can be repeated daily, uncomplicated attacks demonstrating falling scores in association with clinical improvement, in contrast to the rising scores associated with clinical deterioration in those dying early. APACHE II appears to reflect any continuing disease activity and may prove a useful means of monitoring the course of the illness and response to therapy.
Efficacy of nimodipine in cerebral ischemia or hemorrhage. Our studies showed that in an appropriate dose, nimodipine increased local cerebral blood flow with no corresponding increase in local metabolism. Nimodipine treatment given before experimental ischemic insult, resulting from either vascular occlusion or intracranial hemorrhage or after subarachnoid hemorrhage, maintained or improved blood flow and minimized the severity of subsequent brain damage. Lack of benefit from nimodipine treatment after the insult may occur because the inexorable progression of events leading to ischemic neuronal damage, once initiated, cannot be arrested. On the other hand, pharmacokinetic factors may be important, and post-treatment efficacy may depend on administration protocols that achieve an adequate concentration in ischemic tissue sufficiently soon after an insult. Our findings are compatible with the benefit of nimodipine being due to an improvement in blood flow that reduces the severity of ischemia. However, they do not exclude the possibility that treatment may minimize the accumulation of calcium in damaged cells as a result of "cytoprotective" effects.
Reperfusion and readmission of oxygen. Pathophysiological relevance of oxygen-derived free radicals to arrhythmogenesis. We have examined the pathophysiological role of readmission of oxygen (and hence production of oxygen-derived free radicals) in the initiation of reperfusion-induced arrhythmias by separating, on a temporal basis, readmission flow from readmission of oxygen. Isolated rat hearts (n = 12/group) were subjected to 10 minutes of regional ischemia and 10 minutes of reperfusion. In controls reperfused with oxygenated solution (Po2 greater than 600 mm Hg), 92% of hearts developed ventricular fibrillation (VF) during the first 20 seconds of reperfusion, whereas in hearts reperfused with hypoxic solution (Po2 9.3-12.2 mm Hg), the incidence of VF was only 17% (p less than 0.05). Subsequent readmission of control solution (Po2 greater than 600 mm Hg) to the latter group led, within 20 seconds, to the appearance of VF in seven of the 10 hearts (70%) that had not previously fibrillated. To examine whether hypoxic reperfusion had prevented VF or merely delayed its onset, the studies were repeated in separate groups of hearts with the duration of hypoxic reperfusion extended to 5 minutes. In addition, to examine the partial pressure dependence of the relation, the Po2 in the reperfusion solution was set at one of five different levels: greater than 600, 150-192.7, 69-85.6, 9.2-14.8, or 0.0 mm Hg. It was found that hypoxia merely delayed VF onset by 20-40 seconds and did not significantly reduce the incidence of VF, which was 83%, 92%, 67%, 58%, and 58%, respectively. This indicated that readmission of oxygen is unnecessary for the initiation of VF during reperfusion. The hearts that reverted to sinus rhythm during the ensuing 5 minutes (n = 8, 4, 5, 9, and 8, respectively) were used to assess the arrhythmogenic consequences of readmission of oxygen. When control solution (Po2 greater than 600 mm Hg) was readmitted, new episodes of VF were elicited within 20 seconds in a manner that was inversely proportional to the preceding Po2 (p less than 0.05), the incidence of new episodes of VF being 0%, 0%, 40%, 67%, and 86%, respectively. The arrhythmogenic effect of readmission of oxygen was not the result of a sudden increase in heart rate, because a similar arrhythmogenic effect of readmission of oxygen was seen in separate groups of hearts that were paced (350 beats/min) throughout hypoxia and readmission of oxygen. In conclusion, readmission of flow and readmission of oxygen are independent determinants of reperfusion-induced arrhythmias.(ABSTRACT TRUNCATED AT 400 WORDS).
Repetitive conservative surgery for recurrence of endometriosis. We evaluated the recovery of fertility and the relief of pain symptoms in a long-term follow-up of 42 women undergoing repetitive conservative surgery for recurrent endometriosis. The mean age of the patients was 31.1 +/- 4.3 years. At the time of their second operation the disease was stage IV in 14 women, stage III in 25, and stage I in three. After reoperation, the patients were followed for a mean period of 41.8 +/- 30.3 months. Pain symptoms returned in eight women, dysmenorrhea and deep dyspareunia in eight, and pelvic pain in seven. Eight of the 28 women (28.6%) who attempted to conceive achieved a total of 13 pregnancies. The corrected pregnancy rate was 35%, and the cumulative rate at 27 months was 30.7%. A third operation was necessary in six women after a mean period of 35 months. Conservative surgery is an effective therapeutic option for infertile patients with recurrent endometriosis.
Dexamethasone increases plasma levels of albendazole. Therapy of neurocysticercosis with cysticidal drugs is frequently complicated by the exacerbation of symptoms that follows the inflammation triggered by the acute destruction of cysticerci. Treatment of such adverse reactions with dexamethasone is highly effective. However, it has been shown that dexamethasone lowers the plasma levels of praziquantel, thus reducing its cysticidal efficacy. We measured plasma levels of albendazole, another strong cysticidal drug, when dexamethasone was given simultaneously. We found that dexamethasone increased the plasma levels of albendazole by about 50% (P less than 0.002); hence, it seems that cysticercosis and the ensuing inflammation can be treated simultaneously with albendazole and dexamethasone without diminishing the efficacy of the cysticidal drug.
Severe hypertension after liver transplantation in alpha 1 antitrypsin deficiency. Five children with alpha 1 antitrypsin deficiency and terminal liver disease received liver grafts; all five became hypertensive and four developed hypertensive encephalopathy. There was evidence of renal disease preoperatively and renal biopsy specimens showed variable glomerulonephritic histology with IgA nephropathy in one, mesangial-proliferative changes in two, and mesangio-capillary glomerulonephritis type I in two. Four hypertensive episodes were preceded by a fall in creatinine clearance. The association of glomerulonephritis with alpha 1 antitrypsin deficiency in children is more common than has been recognised. Affected patients are prone to severe hypertension of probable renal origin after liver transplantation and the renal lesion may affect long term prognosis.
The in vivo biologic effect of interleukin 2 and interferon alfa on natural immunity in patients with head and neck cancer. Given the association of deficient natural immunity with the risk of metastatic disease, the ability to activate natural killer cell function may have a therapeutic significance. The effect of continuous infusion of interleukin 2 plus intramuscular interferon alfa on natural immune status was, therefore, analyzed in eight patients with head and neck cancer. Also evaluated was the effect of interleukin 2-interferon alfa therapy on lymphokine-activated killer cell activity as well as total lymphocyte count, percent of lymphocyte subsets, and levels of both circulating immune complexes and antibody classes. Both the percent and absolute number of natural killer cells (ie, CD56+ CD3- lymphocytes) within peripheral blood as well as natural killer cell activity against K562 targets increased significantly with treatment. The remaining immune parameters were not significantly altered. The demonstrated capacity to modulate natural immune function supports the potential use of interleukin 2-containing regimens as a preventive measure against metastatic disease in patients with head and neck cancer.
Catecholamine-induced cardiomyopathy in multiple endocrine neoplasia. A histologic, ultrastructural, and biochemical study. A catecholamine-induced dilated cardiomyopathy is reported in a patient with multiple endocrine neoplasia, type 3. A histologic and ultrastructural study has been undertaken in cardiac biopsy samples, together with determination of myocardial Ca++ and cellular membrane fatty acids. Contraction band necrosis of cardiocytes with supercontraction of sarcomeres progressing to myofibrolysis and increased levels of myocardial Ca++ have been found as morphologic and biochemical abnormalities, respectively. No lipoperoxidation of cellular membranes or an alpha-adrenergic mediated reduction of coronary supply could be recognized in the study. We indicate a receptor-mediated intracellular Ca++ overload as the main abnormality responsible for myocardial impairment.
Assessing the clinical effectiveness of preventive maneuvers: analytic principles and systematic methods in reviewing evidence and developing clinical practice recommendations. A report by the Canadian Task Force on the Periodic Health Examination. This paper examines a process for evaluating clinical effectiveness and developing recommendations in which systematic methods are used to review evidence from published clinical research and to reach sound conclusions about appropriate medical policy. The methodology addresses four important components of the analytic process: (1) the criteria that must be satisfied for a clinical practice to be considered effective; (2) proper methods for reviewing evidence from published clinical research to determine whether a clinical practice meets these criteria (including methods for performing comprehensive literature reviews, for judging the quality of individual studies, and for synthesizing or pooling the results of multiple studies); (3) theoretical and practical concerns in translating the results of the scientific review into sound clinical practice recommendations; and (4) the importance of documentation, guidelines, and other safeguards to minimize the effect the reviewers themselves have on the objectivity and consistency of the analytic methods.
Transient ischaemic attacks in young patients: a thromboembolic or migrainous manifestation? A 10 year follow up study of 46 patients. Forty six patients aged 18-39 years with transient ischaemic attacks (TIA) were studied; two thirds were women. Twenty five patients had attacks accompanied by headache, and seven gave a history of common migraine. Only four of 27 angiograms were abnormal; no operable carotid lesion was demonstrated. Over a mean follow up period of 10 years stroke or myocardial infarction (AMI) occurred in all four patients who presented major cerebrovascular risk factors, but in only two of the remaining 42 patients. Thus irrespective of age thromboembolic TIA is a harbinger of stroke or AMI. However, most TIAs under the age of 40 years are caused by a non-embolic benign vascular disorder. The clinical characteristics, long-term prognosis, and possible pathogenesis, for such attacks are often indistinguishable from those of classical migraine. In the absence of cardiovascular risk factors, arteriography does not provide much diagnostic and prognostic information.
Incidence of perioperative myocardial ischemia detected by different electrocardiographic systems To determine the extent to which different electrocardiographic systems account for differences in reported incidence of perioperative myocardial ischemia, the authors simultaneously recorded in 109 patients undergoing coronary artery bypass grafting (CABG) the V5 or modified CM5 lead on five ECG systems by means of a specially constructed common V5 lead. The systems included a Spacelabs Alpha 14 Model Series 3200 ECG Cardule at bandwidths of 0.05-125 Hz and 0.5-30 Hz (a typical operating room monitor), a Marquette Electronics MAC II ECG at 0.05-40 Hz and 0.05-100 Hz (a standard ECG), and a Del Mar Holter recorder at 0.1-100 Hz. Relative ST-segment position and incidence of new ischemia compared to the preoperative ECG were determined in 109 sets of preinduction traces and 877 sets of intraoperative traces. ST-segment position on the three recording systems conforming with the American Heart Association (AHA) low-frequency response recommendations (0.05 Hz) were similar. Compared to the standard ECG, ST-segment position on the Spacelabs at 0.5-30 Hz was consistently more negative. Displacement on the Holter was consistently less negative and less positive. By the 0.1-mV displacement criterion for diagnosis of myocardial ischemia on any one ECG system, 16.5% of patients on arrival and 32.1% of patients intraoperatively suffered new myocardial ischemia. Based on the operating room monitor, arrival and intraoperative ischemia were present in 15.6 and 27.5% of patients, respectively. Ischemia at the same periods was less frequent by the standard ECG system (5.5 and 12.8%, respectively) and least frequent by the Holter recorder (4.6 and 8.3%, respectively).
Crohn's disease in the city of Derby, 1951-85. An epidemiological survey of Crohn's disease in the city of Derby showed that the incidence of the condition increased from 0.7/10(5) per year between 1951 and 1955 to 6.67/10(5) per year between 1981 and 1985 but seemed to reach a plateau between 1976 and 1985. Large bowel Crohn's disease was more common in patients presenting aged 60-79 years than in those aged 20-39 years. The increase in incidence was not solely due to the detection of milder disease. There was no evidence that the Asian (Indian subcontinent) population of Derby was resistant to the development of Crohn's disease.