shukoor65/lab-rag-model huggingface dataset:
Anatomic consideration for sacral screw placement. Instrumentation of the lumbosacral spine increasingly involves screw fixation to the sacrum. Recommended locations and techniques for screw placement vary, particularly when bicortical purchase of the sacrum is performed. The purpose of this study was to describe the critical anatomy and potential injuries to neurovascular and visceral structures anterior to the sacrum. Lack of awareness can lead to life-threatening complications. The study included 22 fresh human cadavers with no prior spinal surgery. Specimens were placed in a prone position, and the lumbosacral spine was exposed. Two 6.5-mm screws were inserted using one of two techniques, respectively: Starting just inferior to the S1 facet one screw was angled 25 degrees caudally and 30 degrees laterally; in the second technique, lateral inclination was increased to 45 degrees. In addition, all specimens had screws placed in the S2 pedicles. An anterior dissection was performed to allow evaluation of the neurovascular and visceral structures at risk for injury by, or adjacent to, the screw tips. All significant neurovascular structures in the area of concern were constant in position. The internal iliac vein and the lumbosacral nerve trunk were most at risk for injury by the 30 and 45 degrees laterally directed screws. The sigmoid colon, though close to the S2 screw, was protected by its mesentery. Screws placed in the S1 pedicle were least likely to injure the neurovascular bundle. A lateral and a midline safe zone were identified.
Plasma sodium-potassium ATPase inhibition activity in low- and normal-renin hypertension. Thirty-seven subjects with low- and normal-renin hypertension (plasma renin activity less than 0.45 ng/L/sec on a 100 mmol Na diet) were studied on a 10 and 100 mmol sodium diet (100 mmol K and 25 mmol Ca) to examine the effect of varied sodium intake on plasma Na,K-ATPase inhibitory activity (NKAIA) (% inhibition). On the 10 mmol Na diet, plasma NKAIA correlated with mean arterial pressure (MAP) (r = 0.384, P = .019). On the 100 mmol Na diet, plasma NKAIA correlated with daily urinary sodium excretion (r = 0.384, P = .019). With the increase in sodium intake, the mean change in MAP was 0.5 +/- 7.8 mm Hg (range -12.7 to 16.3) and the mean change in plasma NKAIA was -4.2 +/- 11.2% inhibition (range -37.5 to 16). The change in MAP was correlated to the change in plasma NKAIA (r = 0.384, P = .019). Plasma NKAIA is related to mean arterial pressure or urinary sodium excretion depending on the dietary sodium intake, and is related to sodium-induced changes in MAP in low and normal renin hypertensive patients.
Ataxic hemiparesis associated with ipsilateral cerebellar syndrome caused by a paracentral gyrus lesion. The authors report a case of ataxic hemiparesis and an ipsilateral cerebellar syndrome in relation to a glioblastoma of the paracentral gyrus region. The physiopathology of this clinical presentation caused by compression of the corticopontine tract is discussed.
Early angioplasty in patients with acute myocardial infarction complicated by hypotension. Emergency percutaneous transluminal coronary angioplasty was performed in 62 patients with acute myocardial infarction complicated by hypotension. All patients were treated within 12 hours of the onset of chest pain. Angioplasty was completely successful (residual lesion less than or equal to 50%) in 48 patients, partially successful (patent vessel greater than 50% residual lesion) in four patients, and unsuccessful in 10 patients. Patients in whom angioplasty was successful had a hospital mortality rate of 19%; those in whom angioplasty was unsuccessful or only partially successful had hospital mortality rates of 60% and 50%, respectively, (p = 0.012). Patients with occlusion of the proximal left anterior descending vessel had the highest failure rate (42%) and the highest mortality rate (67%). Other univariate predictors of hospital mortality were older age and elevated end-diastolic pressure. Successful emergency angioplasty improves mortality in patients with acute infarction complicated by hypotension.
Protection by 16,16-dimethyl prostaglandin E2 and dibutyryl cyclic AMP against complement-mediated hepatic necrosis in rats. 16,16-Dimethyl prostaglandin E2, a known cytoprotective agent, was examined for its ability to protect the liver against complement-mediated necrosis induced by an intravenous injection of a monoclonal antibody against a rat liver-specific antigen in rats. The hepatic injury induced by the antibody was characterized by (a) rapid development of numerous massive hemorrhagic foci of necrotic liver cells, (b) marked increases in serum liver enzyme activities and (c) pronounced reduction in the CH50 level, presumably as a result of complement consumption in the liver. Pretreatment with 16,16-dimethyl prostaglandin E2 at intraperitoneal doses of 20 and 100 micrograms/kg suppressed the hepatic injury, as evidenced by markedly mitigated liver-cell necrosis and much smaller increases in the serum-enzyme activities compared with the values in diseased control animals. The prostaglandin analogue failed to prevent serum complement consumption in response to the antibody injection or affect the CH50 level at the preinjury stage, indicating that neither complement inactivation nor interference with the antigen-antibody reaction was involved in the hepatic protection. The hepatoprotective doses of 16,16-dimethyl prostaglandin E2 produced a significant increase in liver cyclic AMP content in a dose-related manner. In addition, intravenous dibutyryl cyclic AMP at 3 and 10 mg/kg dose-dependently prevented histological and biochemical changes in the hepatic damage without altering the rate of reduction in serum complement activity. Like 16,16-dimethyl prostaglandin E2, dibutyryl cyclic AMP did not affect the preinjury CH50 level.
Iron chelation therapy and lung transplantation. Effects of deferoxamine on lung preservation in canine single lung transplantation. Reperfusion injury is a limiting factor in lung transplantation. Deferoxamine is an iron chelator that inhibits the formation of oxygen-derived free radicals. We investigated the effects of deferoxamine on posttransplantation lung function in a canine model of single lung transplantation. Twelve dogs underwent left lung transplantation after 20- to 24-hour hypothermic storage in a modified Euro-Collins solution. In six experiments donor and recipient received a 10 mg/kg dose of deferoxamine before harvest and transplantation, and 10 mg/kg was added to the preservation solution. Arterial oxygen tension, alveolar-arterial oxygen difference, pulmonary vascular resistance, and dynamic lung compliance were measured. Data were recorded for 6 hours after ligation of the native pulmonary artery. At the end of the study the mean arterial oxygen tension was 175.1 mm Hg for the deferoxamine treated group versus 71.1 mm Hg for the control group (p less than 0.001), and the alveolar-arterial oxygen difference was less in the deferoxamine-treated group: 502.3 versus 606.0 mm Hg (p less than 0.001). The mean pulmonary vascular resistance was lower throughout the study, and after 6 hours it was 455.1 dynes/sec/cm(-5) in the deferoxamine-treated group versus 663.7 dynes/sec/cm(-5) in the control group (p less than 0.035). Compliance was similar in both groups. We conclude that deferoxamine improves lung preservation and early posttransplantation function in canine single lung transplantation.
Comparative efficacy and safety of bepridil and diltiazem in chronic stable angina pectoris refractory to diltiazem. The Bepridil Collaborative Study Group. The efficacy and safety of bepridil hydrochloride (200 to 400 mg/day) were evaluated in patients with chronic stable angina refractory to maximal tolerated doses of diltiazem (median 360 mg/day) in a randomized, multicenter, double-blind, parallel study. Baseline diltiazem data were obtained during a 2-week period, after which 86 patients were randomized to bepridil (n = 46) or diltiazem (n = 40). Angina frequency, nitroglycerin consumption and ischemic manifestations induced by exercise treadmill testing were evaluated over 8 weeks. Bepridil significantly (p less than 0.05) increased time to angina onset, time to 1 and 2 mm of ST-segment depression, total exercise time and total work over baseline values. Changes in time to angina onset and time to 1 mm of ST-segment depression were significantly (p less than 0.05) greater for bepridil than for diltiazem. Angina frequency and nitroglycerin consumption did not differ significantly between groups. Compared with baseline, bepridil significantly (p less than 0.001) decreased heart rate (mean 4 beats/min) and prolonged QTc (mean 35 ms). The most frequent adverse effects in both groups were nausea, asthenia, dizziness, headache and diarrhea. Four patients taking bepridil and 1 taking diltiazem withdrew from the study because of adverse reactions. No sudden deaths, myocardial infarctions or instances of sustained ventricular tachycardia or torsades de pointes occurred in either group. The data indicate that bepridil provided safe and effective antianginal and antiischemic therapy in patients with chronic stable angina who exhibited less than optimal response to maximal tolerated doses of diltiazem.
Combined vitrectomy, cataract extraction, and posterior chamber intraocular lens implantation in diabetic patients. Combined extracapsular cataract extraction, pars plana vitrectomy, and posterior chamber intraocular lens implantation was performed in six eyes with proliferative diabetic retinopathy. These eyes all had minimal iris vascular changes and were at reasonably low risk for developing intraoperative and postoperative complications. The surgery must be relatively brief and the endophotocoagulation accurate. Initial visual acuities ranged from light perception to 4/200. With an average follow-up of 9.7 months, final acuities ranged from 4/200 to 20/40.
Inefficacy and proarrhythmic effects of flecainide and encainide for sustained ventricular tachycardia and ventricular fibrillation. OBJECTIVE: To assess the efficacy of encainide and flecainide in treating patients with sustained ventricular arrhythmias. DESIGN: Patients were treated with encainide or flecainide. Efficacy was assessed by comparing the results of programmed ventricular stimulation while patients received therapy with the results while they were drug free. SETTING: The electrophysiology laboratory of the University of California at San Francisco. PATIENTS: Forty-nine patients with spontaneous or inducible sustained ventricular tachycardia or ventricular fibrillation for whom treatment with at least one class IA antiarrhythmic agent had failed. INTERVENTIONS: Patients were treated with encainide, 35 to 50 mg three or four times daily, or flecainide, 100 to 200 mg twice daily. RESULTS: Arrhythmia worsened early in 5 of 16 patients receiving encainide and 3 of 33 patients receiving flecainide. Patients with poor left ventricular function were more likely to exhibit proarrhythmia (P = 0.02). Nine of eleven patients receiving encainide and 23 of 28 patients receiving flecainide who had repeat programmed ventricular stimulation while receiving drug therapy still had inducible, poorly tolerated ventricular tachycardia. CONCLUSION: Encainide and flecainide have a low efficacy rate and a high incidence of worsening of arrhythmia in patients with sustained ventricular arrhythmias, particularly when this condition is associated with poor left ventricular function.
Serial angiography in a spontaneous dissecting anterior cerebral artery aneurysm. Intracranial dissecting aneurysms are uncommon, and little is known concerning the natural history of these lesions. In this paper we present a rare case of dissecting aneurysm of the anterior cerebral artery in which a true diagnostic sign of "double lumen" was demonstrated. Sequential changes in angiographic features shown on serial angiographic studies are described, and diagnosis is briefly discussed.
Pathogenesis of severe acute respiratory infections in the developing world: respiratory syncytial virus and parainfluenza viruses. Respiratory syncytial virus (RSV) and parainfluenza viruses (PIVs) are the most frequently isolated pathogens in infants and children with acute lower respiratory infection (LRI) in the developed world. Less information is available about their importance in LRI in the developing world, but they are probably important there also. The pathogenesis of viral bronchiolitis and pneumonia involves inoculation and early replication in the upper respiratory tract, followed by aspiration into the lower respiratory tract when both the mucosal and systemic immune systems are involved in a specific response. Both disease and recovery reflect processes of viral replication (with attendant cellular destruction) and of immune response (with attendant direct cellular destruction and release of pathogenic, along with beneficial, mediators). Factors predisposing to bacterial superinfection are poorly understood except in animal models. Conditions leading to heightened susceptibility to severe disease in the developed world are particularly common in the developing world. Increasing information on RSV and PIV infections in the developing world will likely point to their importance. Strategies for prevention of severe illnesses due to these viruses will follow from concepts elucidated through animal models and studies of infants in the developed world.
Magnetic resonance imaging in the staging of renal cell carcinoma. A prospective study has been carried out to examine the role of magnetic resonance imaging (MRI) in the investigation of renal cell carcinoma in 24 patients. In all cases the inferior vena cava (IVC) was well demonstrated with MRI. In 14 out of 15 patients where surgical correlation was available, the MRI and operative staging were in agreement. Magnetic resonance imaging and computed tomographic (CT) staging were in agreement in 16 out of the 17 patients where both were performed. In one case, CT suggested hepatic invasion but this was found not to be present on MRI and at operation. Magnetic resonance imaging also provided substantial additional information in three patients, including two cases where MRI demonstrated a patent IVC that appeared occluded on CT (one of which also had vertebral metastases seen on MRI but missed on CT) and one case where CT failed to demonstrate minimal involvement of the IVC. Magnetic resonance imaging is an accurate means of staging renal cell carcinoma with clear advantages over CT. In no case in this series was inferior vena cavography found to be necessary.
Monitoring of irrigating fluid absorption during transurethral prostatectomy. A study in anaesthetised patients using a 1% ethanol tag solution. A simple, reliable method to detect absorption of irrigating fluid during transurethral prostatectomy is to tag irrigating fluids with 1% ethanol and monitor expired breath ethanol concentrations. This method correlated well (n = 0.79) with other existing methods of absorption monitoring in 20 anaesthetised patients. Ethanol (1%) tagging does not alter the optical quality of the irrigating fluid and is harmless to the patient. The technique is non-invasive, repeatable, cheap and gives instant results. It can be used in anaesthetised or awake patients and can detect absorption of as little as 100-150 ml in any 10-minute period.
Long-term effect of thrombolytic therapy on left ventricular ejection fraction after acute myocardial infarction. To assess the long-term effect of thrombolytic therapy on left ventricular (LV) systolic function, 222 patients with acute myocardial infarction treated with intravenous tissue plasminogen activator within 4 hours of symptom onset underwent assessment of LV ejection fraction (EF) by radionuclide equilibrium angiography at hospital discharge and 1 year later. Mean EF at hospital discharge (46 +/- 12) was similar to that at 1 year (45 +/- 13). Stepwise multivariate linear regression analysis identified EF at discharge and patency of the infarct-related artery before discharge as independent predictors of EF change at 1 year (p = 0.0002 and 0.003, respectively). Random assignments to invasive versus conservative treatment strategies or to early versus delayed beta-blocker therapy did not affect EF change during follow-up. No significant deterioration of EF was observed in patients with larger infarcts. However, EF decreased from 45 +/- 10 at hospital discharge to 39 +/- 12 (p = 0.005) at 1-year follow-up in a subgroup of patients with history of prior infarction. Thus, patients with acute myocardial infarction, treated with intravenous tissue plasminogen activator early after onset of symptoms, appear to have stable LV function between hospital discharge and 1 year follow-up. The change in EF between hospital discharge and 1 year can be predicted from the EF value at discharge, patency of the infarct-related artery before discharge and history of previous myocardial infarction.
Effect of insulin and plasma amino acid concentration on leucine metabolism in cirrhosis. Clinically stable patients with cirrhosis demonstrate insulin resistance with regard to glucose metabolism. However, much less is known about the two major factors, insulin and plasma amino acid concentration, that regulate protein metabolism in cirrhotic patients. To examine this question, we performed paired euglycemic insulin clamp studies in combination with 14C-leucine and indirect calorimetry. In the first study insulin alone was infused, and the plasma amino acid concentration was allowed to decline. During the second study a balanced amino acid solution was infused with insulin to increase the total plasma amino acid concentration approximately twofold. Insulin-mediated glucose disposal (4.68 vs. 6.45 mg/kg-min, p less than 0.01) was significantly impaired by 30% in cirrhotic patients during both insulin clamp studies. In the postabsorptive state, cirrhotic patients manifested low plasma leucine (76 vs. 102 mumol/L) and alpha-ketoisocaproate (19 vs. 30 mumol/L) concentrations, but all parameters of leucine turnover were normal. When insulin alone was infused, the endogenous leucine flux (an index of protein degradation) declined similarly in cirrhotic patients (30.8 mumol/m2-min) and control (26.9) subjects, and this was accompanied by a similar decrease in plasma leucine concentration (31% vs. 33%). The decline in circulating leucine concentration was accompanied by a parallel decline in leucine oxidation (5.1 vs. 4.6 mumol/m2-min) and nonoxidative (28.9 vs. 26.0 mumol/m2-min) leucine disposal, which were of similar magnitude in cirrhotic patients and control subjects, respectively. In both cirrhotic patients and control subjects, combined hyperinsulinemia/hyperaminoacidemia elicited a similar stimulation of nonoxidative leucine disposal (an index of protein synthesis) and leucine oxidation while causing a greater suppression of endogenous leucine flux than observed with insulin alone. Thus the suppressive effect of insulin on protein degradation and the stimulatory effect of insulin/amino acid infusion on protein synthesis are not impaired in cirrhotic patients, demonstrating a clear-cut dissociation between the effects of insulin on protein and glucose metabolism.
Comparative efficacy of cimetidine, famotidine, ranitidine, and mylanta in postoperative stress ulcers. Gastric pH control and ulcer prevention in patients undergoing coronary artery bypass graft surgery. To determine the comparative efficacy of several histamine (H2)-receptor antagonists (cimetidine, famotidine, and ranitidine) and the antacid Mylanta-II (Stuart Pharmaceuticals, Wilmington, DE) in gastric pH control and the prevention of postoperative stress ulceration, a prospective, randomized study was performed in a homogeneous population of patients with elective coronary artery bypass. None of the 57 patients in the study population had a documented history of ulcer disease. There were four treatment groups, each with similar demographics (age and sex). Cimetidine-treated group consisted of 15, famotidine-treated group of 18, ranitidine-treated group of 19, and antacid-treated group of 5 patients. There was no hemodynamically significant postoperative gastrointestinal bleeding in any of the patients. When the agents were compared for efficacy of gastric pH control, statistically better pH control was found in the famotidine- and ranitidine-treated groups (P less than 0.003) than in the cimetidine-treated group (pH less than or equal to 4.0) during the 20-hour observation period. Side effects (hematologic and neurological) were noted only in the cimetidine-treated group. The results of this study indicate that in patients in postoperative intensive care, better gastric pH control, and thus prevention of gastric stress ulcers, is achieved with either famotidine or ranitidine rather than cimetidine or antacid.
Abnormal permeability precedes the development of a gluten sensitive enteropathy in Irish setter dogs. Intestinal permeability to 51Cr-EDTA was examined during the development of gluten sensitive enteropathy in dogs bred from affected Irish setters and reared on a normal wheat containing diet. Comparisons were made with litter mates reared on a gluten free diet and with a control group of age matched, clinically healthy Irish setters reared on the normal diet. Studies at 4, 6, 8, and 12 months of age were correlated with morphometric and biochemical examinations of peroral jejunal biopsy specimens. Permeability was increased at all ages in the group fed gluten free diet compared with control dogs, although there were no differences in villus height, intraepithelial lymphocyte density, and alkaline phosphatase activity. At four months, permeability in the normal diet group was greater than in controls, although comparable with that in the gluten free diet group. Permeability in the normal diet group increased further in conjunction with the development of partial villus atrophy and reduced alkaline phosphatase activity, and by 12 months permeability was significantly greater than in their gluten free diet litter mates and the control dogs. The findings suggest that an underlying permeability abnormality may be involved in the pathogenesis of gluten sensitive enteropathy in Irish setter dogs.
Acute inflammation: the underlying mechanism in delayed onset muscle soreness? It is well documented in animal and human research that unaccustomed eccentric muscle action of sufficient intensity and/or duration causes disruption of connective and/or contractile tissue. In humans, this appears to be associated with the sensation of delayed onset muscle soreness (DOMS). During the late 1970's, it was proposed that this sensation of soreness might be associated with the acute inflammatory response. However, subsequent research failed to substantiate this theory. The present article suggests that the results of much of the research concerning DOMS reflect events typically seen in acute inflammation. Similarities between the two events include: the cardinal symptoms of pain, swelling, and loss of function; evidence of cellular infiltrates, especially the macrophage; biochemical markers such as increased lysosomal activity and increased circulating levels of some of the acute phase proteins; and histological changes during the initial 72 h. In the final section of this paper, a theoretical sequence of events is proposed, based on research involving acute inflammation and DOMS.
alpha Fetoprotein producing early gastric cancer with liver metastasis: report of three cases. Three cases of alpha fetoprotein producing early gastric cancer are presented. Liver metastases occurred in all patients shortly after curative gastrectomy and all died within two years. The incidence of liver metastasis was significantly higher than that in alpha fetoprotein negative early gastric carcinoma (p less than 0.001). The incidences of lymph node metastasis and invasion in lymph vessels and veins were also substantially higher in this group of patients. Two radical hepatic resections, including extended right lobectomy, were performed on one patient but the tumour recurred immediately.