shukoor65/lab-rag-model huggingface dataset:
Suppression of eicosanoid biosynthesis during coronary angioplasty by fish oil and aspirin. BACKGROUND. Percutaneous transluminal coronary angioplasty (PTCA) is an acute, localized stimulus to platelet and vascular function. Periprocedural cardiovascular complications are reduced by moderate-dose aspirin (ASA), presumably due to inhibition of thromboxane (TX) A2. METHODS AND RESULTS. Excretion of TXA2 and prostacyclin (PGI2) metabolites in urine increased during PTCA. Pretreatment for 3 days with either moderate- (325 mg/day) or low-dose (80 mg/day) ASA inhibited the increase in both eicosanoids. Pretreatment for 3 weeks with fish oil (10 g/day) only partially suppressed TXA2. Formation of trienoic eicosanoids and accumulation of omega-3 fatty acids in platelet membranes confirmed fish oil ingestion. Although basal PGI2 was not inhibited, the PTCA-related increment was suppressed. CONCLUSIONS. PTCA results in an acute, transient alteration of eicosanoid biosynthesis consistent with accelerated platelet-vascular interactions. Pretreatment for 3 days with moderate or low doses of ASA suppresses TXA to a similar extent during PTCA, and their effects on acute cardiovascular complications of this procedure are likely to be comparable. It is unlikely that even prolonged pretreatment with fish oil can substitute for the platelet inhibitory action of ASA during PTCA. Suppression of PGI2 may contribute to the residual acute periprocedural complication rate in patients taking ASA.
Etidronate for hypercalcemia of malignancy and osteoporosis. The biphosphonates are becoming well established as effective agents for the treatment of metabolic bone diseases. Etidronate disodium is the only biphosphonate approved by the U.S. Food and Drug Administration. Accepted indications for etidronate therapy are symptomatic Paget's disease, heterotopic ossification and hypercalcemia of malignancy. An unapproved, but apparently successful use is treatment of postmenopausal osteoporosis. Both oral and intravenous preparations are available. Newer biphosphonates, which may be more efficacious and less toxic than etidronate, are being studied.
Comparative angiographic quantitative analysis of the immediate efficacy of coronary atherectomy with balloon angioplasty, stenting, and rotational ablation. Interventional cardiology has branched in two directions: devices that primarily dilate coronary stenoses and those that debulk coronary tissue. Presently the optimum coronary intervention has not been found. While patients are awaiting randomized trials, a comparison based on matched quantitative coronary analysis may be useful to evaluate results of new interventional techniques. Therefore we compared 51 patients undergoing atherectomy with individually matched patients who were undergoing balloon angioplasty and stenting. The lesions were matched according to location of stenosis and reference diameter. Atherectomy and stenting resulted in larger gains in minimal luminal diameter compared with conventional balloon angioplasty. The minimal luminal diameter was increased from 1.2 +/- 0.4 mm to 2.6 +/- 0.4 mm in the atherectomy group and from 1.2 +/- 0.3 mm to 1.9 +/- 0.4 mm in the angioplasty group (p less than 0.00001). Atherectomy and stenting resulted in similar gains in minimum luminal diameter (1.4 mm vs 1.3 mm, p = NS). In addition, atherectomy and stenting appear to be more effective in resisting elastic recoil because of tissue removal and an intrinsic dilating effect, respectively. In matched populations directional atherectomy and stenting appear to be more effective intracoronary interventional devices than balloon angioplasty based on the immediate results. However, atherectomy is limited in smaller coronary vessels because of its larger size.
Adaptive changes in the periphery and their therapeutic consequences. Systemic vasoconstriction in chronic heart failure is due to several compensatory mechanisms with different time courses. Peripheral vasoconstriction mediated by increased sympathetic tone and activation of the plasma renin-angiotensin system may act primarily for short-term control. The effects of the vascular renin-angiotensin system, impaired flow-dependent, endothelium-mediated dilation (resulting from chronically reduced flow) and structural alterations of the vessel wall slowly emerge with time. In addition, fluid retention may contribute to increased vascular stiffness in chronic heart failure. Improved cardiac output with acute administration of vasodilators and inotropes is not immediately translated into increased blood flow to skeletal muscle, because (1) the reversal of the peripheral alterations described develops slowly over time (in fact, vasodilators and inotropes given acutely may cause redistribution of blood flow in skeletal muscle without improving oxygen availability); and (2) intrinsic abnormalities of skeletal muscle exist in chronic heart failure (e.g., due to chronic deconditioning, resulting in reduced oxidative capacity of skeletal muscle, as suggested by ultrastructural analysis and nuclear magnetic resonance spectroscopy). Drugs that interfere with the underlying compensatory mechanisms (e.g., renin-angiotensin system) without development of tolerance during long-term therapy exert beneficial effects after long-term treatment (e.g., the beneficial effects of angiotensin-converting enzyme inhibitors are, in part, due to peripheral mechanisms--the inability of the peripheral vessels to dilate--and to improvement of peripheral oxygen extraction).
Extracorporeal lithotripsy. An important adjunct in the nonoperative management of retained or recurrent bile duct stones. Retained or recurrent bile duct stones can be successfully removed in up to 80% to 85% of patients with the use of percutaneous or endoscopic techniques. However, problems related to difficult biliary access, large stones, and biliary strictures may decrease the success rate of this approach. We evaluated the safety and efficacy of extracorporeal shock-wave lithotripsy (ESWL) in 16 patients with complicated biliary stones treated prospectively over a 24-month period. Successful stone fragmentation was achieved in 15 patients (94%) using a Dornier HM3 lithotripter (average of 2290 shocks at 22 kV). Three patients (19%) required a second ESWL treatment. Biliary clearance of stone fragments was spontaneous in seven (43%) of the patients and required additional treatment in eight (57%) of the patients. Complications from ESWL were minor and included transient hematuria and ecchymoses at the skin entry site. Extracorporeal shock-wave lithotripsy failed in one patient (6%) with a biliary stricture and surgery was required. At hospital discharge, all patients were asymptomatic and stone free. Treatment with ESWL appears to be a safe and effective adjunct for selected patients with complex biliary stone disease.
The orthostatic tachycardia syndrome: evaluation of autonomic function and treatment with octreotide and ergot alkaloids. Orthostatic tachycardia is a poorly understood syndrome in which patients develop dizziness, diaphoresis, or palpitations upon shifting from the supine to the upright posture. The present study was performed to determine whether autonomic neuropathy might be present in these patients, and whether the abnormal hemodynamic response to standing might be the result of failure of reflex vasoconstriction. We measured autonomic function in 9 patients with idiopathic orthostatic tachycardia and 2 patients with orthostatic tachycardia and insulin-dependent diabetes mellitus and compared them to 33 age-matched controls. Although most patients with orthostatic tachycardia had normal vasomotor reflexes and normal surface potential amplitudes, the latency of the autonomic response, a measure of sympathetic nerve conduction velocity, was prolonged in the soles (2.44 +/- 0.08 s in patients with idiopathic orthostatic tachycardia vs. 2.12 +/- 0.04 s in controls; P less than 0.005). In 6 of 9 patients, however, the latencies were within the normal range. Autonomic surface potentials were absent in 1 diabetic patient with orthostatic tachycardia; the latency of the response in the feet was greatly prolonged (2.95 s) in the second patient. We also assessed the response of orthostatic tachycardia patients to octreotide and dihydroergotamine, which are known to have a pressor effect in patients with recognized forms of autonomic neuropathy. These agents, in combination, suppressed orthostatic tachycardia (from 116 +/- 7 to 89 +/- 6 beats/min; P less than 0.001) in patients with this syndrome. In summary, our data indicate that evidence of autonomic dysfunction is present in only a minority of patients with orthostatic tachycardia. Nevertheless, administration of the vasoconstrictor drugs dihydroergotamine and octreotide can prevent the abnormal hemodynamic response to the upright posture shown by patients with this syndrome.
Crohn disease in the pediatric patient: CT evaluation. Computed tomographic (CT) scans and medical records of 25 children (age range, 10-18 years) with pathologically proved Crohn disease were reviewed to better define the role of CT in the management of pediatric patients with Crohn disease. CT findings included small bowel thickening (range, 5-10 mm) (n = 20), colonic wall thickening (range, 6-15 mm) (n = 15), and small bowel dilation (n = 5). Mesenteric abnormalities such as adenopathy and focal fatty proliferation were seen in 11 to 18 patients, respectively. Extraluminal complications were easily identified with CT. Abscesses were noted in seven patients, inflammatory masses in four, and perirectal or perineal inflammation in 10. Fistulas were detected in four patients. The authors conclude that CT should be the initial imaging study performed in children with known Crohn disease and a changing pattern of clinical symptoms.
Effect of bisoprolol on blood pressure and arterial hemodynamics in systemic hypertension. Blood pressure, heart rate, common carotid and brachial arterial hemodynamics using pulsed Doppler flowmetry and pulse wave velocity determinations were evaluated using a double-blind crossover design versus placebo in 14 patients with sustained essential hypertension treated by the selective beta 1 blocking agent bisoprolol. Blood pressure and heart rate significantly decreased after bisoprolol, whereas no significant change occurred in the diameter, the blood flow and in the vascular resistance of the carotid and brachial circulations. Pulse wave velocity significantly decreased in the brachioradial and the carotid femoral areas. The decrease in the latter was -1.6 +/- 0.8 m/s with bisoprolol and -0.06 +/- 0.80 m/s with placebo (p = 0.001). Brachial artery compliance significantly increased from 117 +/- 49 to 205 +/- 84 cm4 x dynes-1 x 10(9) (p = 0.001), indicating that the antihypertensive effect of beta 1 blockade is associated with an improvement in the viscoelastic properties of the brachial artery wall.
J. Maxwell Chamberlain Memorial Paper. Role of staging in prognosis and management of thymoma. Eighty-five patients operated on for thymoma from 1972 to 1989 were evaluated, 32 with myasthenia gravis and 53 without. Masaoka staging revealed stage I disease in 45 (53%), stage II in 23 (27%), stage III in 14 (16%), and stage IVa in 3 (4%). There was no operative mortality. Actuarial survival at 10 years was 63.7% for all patients: 78.3% for those in stage I, 74.7% for those in stage II, and 20.8% for those in stage III. There was no recurrence in patients in stage I. Mediastinal recurrence developed in 4 patients in stage II considered to have noninvasive disease by the surgeon. It is recommended that all patients be followed up for a minimum of 10 years and that all patients in stages II and III receive postoperative radiotherapy. The presence of myasthenia gravis is no longer considered as an adverse factor in survival.
Rhabdomyolysis following total hip arthroplasty. We report six cases of contralateral limb involvement during total hip arthroplasty including swelling of the gluteal muscle compartments, rhabdomyolysis, myoglobinuria, and sciatic nerve palsy. The risk factors for such complications include obesity, prolonged operative time, and positioning in the lateral decubitus position. The laboratory and clinical findings are consistent with a gluteal muscle crush-injury with consequent compartment syndrome. The patients should be treated conservatively as symptoms can be expected to resolve.
Usefulness of the corticotropin-releasing hormone test during bilateral inferior petrosal sinus sampling for the diagnosis of Cushing's disease. Inferior petrosal sinus blood sampling for ACTH measurement (IPSS) is used for the differential diagnosis of ACTH-dependent Cushing's syndrome and for the preoperative location of pituitary microadenomas. Intermittent ACTH secretion from pituitary adenomas may result in insignificant differences between petrosal and peripheral ACTH levels at the time of sampling. Thus, pituitary stimulation during IPSS may improve the procedure. The aim of the study was to evaluate the usefulness of CRH injection in combination with IPSS. Twenty-two patients with Cushing's disease (CD; 5 macroadenomas, 16 microadenomas, and 1 corticotroph hyperplasia) and 5 patients with ectopic ACTH syndrome were studied. Bilateral IPSS was successfully carried out on 25 patients. Patients with ectopic ACTH syndrome had, before and after CRH injection, central to peripheral ACTH gradients below 1.7. Four patients with CD had basal gradients below 1.4. After CRH administration all patients with CD had gradients above 3.2. Despite correct location of central catheters, the predicted location of pituitary microadenomas was erroneous in 41% of the cases. It was not improved after CRH injection. In conclusion, the combination of CRH injection with IPSS was useful for the differential diagnosis of ACTH-dependent Cushing's syndrome, as it increased the discrimination of the procedure. On the contrary, it was useless for the preoperative location of pituitary microadenomas, which was poorly predicted by IPSS.
Comparison of neuroendocrine activation in patients with left ventricular dysfunction with and without congestive heart failure. A substudy of the Studies of Left Ventricular Dysfunction (SOLVD). Neuroendocrine activation is known to occur in patients with congestive heart failure, but there is uncertainty as to whether this occurs before or after the presence of overt symptoms. In the Studies of Left Ventricular Dysfunction (SOLVD), a multicenter study of patients with ejection fractions of 35% or less, we compared baseline plasma norepinephrine, plasma renin activity, plasma atrial natriuretic factor, and plasma arginine vasopressin in 56 control subjects, 151 patients with left ventricular dysfunction (no overt heart failure), and 81 patients with overt heart failure before randomization. Median values for plasma norepinephrine (p = 0.0001), plasma atrial natriuretic factor (p less than 0.0001), plasma arginine vasopressin (p = 0.006), and plasma renin activity (p = 0.03) were significantly higher in patients with left ventricular dysfunction than in normal control subjects. Neuroendocrine values were highest in patients with overt heart failure. Plasma renin activity was normal in patients with left ventricular dysfunction without heart failure who were not receiving diuretics and was significantly increased (p less than 0.05) in patients on diuretic therapy. We conclude that neuroendocrine activation occurs in patients with left ventricular dysfunction and no heart failure. Neuroendocrine activation is further increased as overt heart failure ensues and diuretics are added to therapy.
Use of azathioprine or 6-mercaptopurine in the treatment of Crohn's disease. The efficacy and safety of therapy with azathioprine/6-mercaptopurine was studied in 78 patients with Crohn's disease. Mean duration of therapy was 1.6 years; 52 patients were treated greater than or equal to 6 months. All patients were also on other antiinflammatory medications. Evaluations included self-assessment and physician's assessment of well-being, functional capacity, general clinical response, clinical activities indices (National Foundation for Ileitis and Colitis/International Organization for the Study of Inflammatory Bowel Disease and Harvey-Bradshaw), and achievement of specific therapeutic goals. General clinical condition improved in 70% of the patients. Median response time was 3 months. The average Harvey-Bradshaw score decreased 37% with therapy, and a decrease of greater than or equal to 30% occurred in 66% of the subjects. An overall 72% achievement rate for specified therapeutic goals included controlling refractory disease, 73%; corticosteroid "sparing," 76%; and lessening fistulization, 63%. Nine patients got worse despite therapy. Adverse effects requiring discontinuation of therapy occurred in 10%, whereas dosages were briefly lowered for mild side effects in another 10%. This study demonstrates the effectiveness and safety of azathioprine/6-mercaptopurine in the majority of selected patients with chronic, unremitting, or steroid-requiring Crohn's disease.
Clinical, biochemical, and morphological correlates in patients bearing growth hormone-secreting pituitary tumors with or without constitutively active adenylyl cyclase. Somatic mutations in the alpha-chain (alpha s) of the stimulatory regulatory protein of adenylyl cyclase (Gs) causing constitutive activation of the enzyme have been identified in a subset of human GH-secreting pituitary adenomas. This study reports on the differences between acromegalic patients bearing tumors without (group 1; n = 51) or with (group 2; n = 29) this alteration. No difference in age, sex, clinical features, duration of the disease, or cure rate was observed between the two groups. By contrast, group 2 patients had higher basal GH levels than group 1. Moreover, a significant difference in sellar morphology was found; group 2 patients more frequently showed sellas of normal size (grade I) than group 1. Hypersecretory activity of group 2 tumors was also apparent at electron microscopy; contrary to those of group 1, cells of group 2 tumors were densely granulated and showed prominent rough endoplasmic reticulum and Golgi complex. With respect to group 1, group 2 patients were less responsive to GH-releasing hormone, while they were more sensitive to somatostatin- and dopamine-induced GH inhibition. These results suggest that patients with constitutively active adenylyl cyclase have hyperactive tumors; the sensitivity of these tumors to inhibitory agents (somatostatin and dopamine), possibly counteracting the expression of activating mutations, might explain the low rate of tumor growth.
Hearing improvement after acoustic tumor removal. Hearing improvement after removal of an acoustic tumor is an uncommon occurrence. Hearing improvement was observed in 8.5% of acoustic tumor removals performed using the middle fossa approach in an attempt to preserve hearing. Improvement in speech discrimination occurred most frequently and was of greatest magnitude compared with changes in the speech reception threshold or pure-tone average. No preoperative factors were predictive of postoperative hearing improvement. Findings support the conclusion that candidates for hearing preservation surgery should be chosen on the merits of their existing preoperative hearing and not on the basis of anticipated improvement.
The development of penicillin-resistant oral streptococci after repeated penicillin prophylaxis. Oral streptococci may cause infective endocarditis in patients with susceptible cardiac disease after dental treatment. Multiple dental visits, each preceded by penicillin prophylaxis, may result in the unwanted development of resistant oral streptococci. This study was undertaken to determine whether resistant oral streptococci would develop after the repeated use of penicillin prophylaxis in healthy adults. Plaque samples were collected from 20 subjects on each Monday for 5 successive weeks. Each subject was administered 2 gm penicillin V followed by 1 gm 6 hours later (standard prophylaxis regimen of the American Heart Association), on three successive Mondays (weeks 2, 3, and 4). The total cultivable oral streptococci and penicillin-resistant oral streptococci were determined for each plaque sample, and representative colonies of resistant streptococci were speciated. During the study, there was a significant increase in the number of subjects who harbored penicillin-resistant oral streptococci. However, with the exception of one subject who had resistant streptococci throughout the study, the number of resistant strains represented only 0.0003% to 0.41% of the total cultivable oral streptococci.
Kinetic modeling of in vivo--nuclear magnetic resonance spectroscopy data: 5-fluorouracil in liver and liver tumors. Kinetic modeling has been applied to the time course of the nuclear magnetic resonance signal intensities of 5-fluorouracil and the sum of its catabolites, alpha-fluoro-beta-ureido propanoic acid and alpha-fluoro-beta-alanine, as monitored in liver tumors of seven patients with cancer after brief intraarterial infusion of 5-fluorouracil. Because these data represent only relative tissue concentrations, only ratios of clearance and volume parameters can be estimated (e.g., clearance/central volume of distribution or central volume of distribution/steady-state volume of distribution). On the other hand, parameters that do not refer to volumes, such as half-lives or maximal velocity of metabolic conversion of a nonlinear model, can be estimated in absolute terms. A nonlinear three-compartment model gave satisfactory fits with all of the individual data sets. Kinetics of 5-fluorouracil and catabolites were similar in five patients with metastases of colorectal adenocarcinomas but differed from those of two patients with cholangiocarcinoma and metastases of an anaplastic carcinoma of unknown origin, respectively.
Percutaneous cooling of ischemic myocardium by hypothermic retroperfusion of autologous arterial blood: effects on regional myocardial temperature distribution and infarct size. The effects of synchronized coronary venous retroperfusion of cooled autologous arterial blood on regional myocardial temperature distribution and infarct size were studied in open chest dogs with 3.5 h of left anterior descending coronary artery occlusion. After 30 min of occlusion, the dogs were randomly assigned to one of three groups: 1) untreated control group (n = 5), 2) normothermic retroperfusion group (infusion temperature 32 degrees C) (n = 7), and 3) hypothermic retroperfusion group (infusion temperature 15 degrees C) (n = 7). Regional myocardial temperatures were measured by using needle-tipped thermistors stabbed in the 1) anterior wall distal to the occlusion site, 2) anterior wall proximal to the occlusion site, 3) left lateral wall, 4) posterior wall, and 5) right ventricular free wall. Rectal and pulmonary artery temperatures were also measured. In the hypothermic retroperfusion group, the anterior wall temperature decreased rapidly by 5 degrees C at 15 min of retroperfusion (p less than 0.05 vs. normothermic retroperfusion or untreated control groups), whereas the temperature at other sites decreased with a linear trend over time. Myocardial temperatures in the ischemic area (distal anterior wall) were generally lower than those in the other sites during the first 60 min of hypothermic retroperfusion and the largest intramyocardial temperature difference (3.6 degrees C) was found at 15 min after retroperfusion. Infarct size expressed as a percent of the risk area was significantly smaller in the hypothermic retroperfusion group (6.2 +/- 3.3%) than in the control (64.9 +/- 14%) or normothermic retroperfusion groups (24.1 +/- 6.7%).