shukoor65/lab-rag-model huggingface dataset:
Increased Na(+)-H+ exchange in jejunal brush border membrane vesicles of spontaneously hypertensive rats. The spontaneously hypertensive rats and their genetically matched controls, Wistar-Kyoto, serve as models of essential hypertension. The present study was undertaken to determine whether brush border membrane vesicles obtained from jejunal enterocytes of spontaneously hypertensive rats show increased Na(+)-H+ exchange as part of a generalized membrane disorder. Brush border membrane vesicles were prepared from the jejunum of adult spontaneously hypertensive rats and Wistar-Kyoto rats using an Mg2+/ethylene glycol tetraacetic acid precipitation method. Uptake of 22Na by these vesicles was found to be into an osmotically sensitive intravesicular space rather than mere binding. Initial Na+ uptake by brush border membrane vesicles was greater in spontaneously hypertensive rats than in Wistar-Kyoto rats (P less than 0.05). Higher total and amiloride-sensitive Na+ uptake in spontaneously hypertensive rats occurred in the presence of an outwardly directed pH gradient, and uptake became statistically similar to that of Wistar-Kyoto rats in the absence of a pH gradient. Moreover, amiloride-insensitive Na+ uptake under an outwardly directed pH gradient did not differ significantly between the two groups. The enhanced Na(+)-H+ activity in spontaneously hypertensive rats is not due to altered membrane permeability to protons, as is shown by acridine orange-quenching studies. Kinetic studies for amiloride-sensitive Na+ uptake showed a greater Vmax in spontaneously hypertensive rats compared with Wistar-Kyoto rats (1.46 +/- 0.05 vs. 1.08 +/- 0.08 nmol.mg protein-1.7 s-1) but the Km values were similar in the two groups. These finding, along with similar findings previously reported in vascular smooth muscle and renal tissue of SHR, strongly suggest that an increased Na(+)-H+ exchange is related to the development of hypertension.
Changes in lipids and lipoproteins with long-term estrogen deficiency and hormone replacement therapy. Cross-sectional data of the long-term effects of estrogens, androgens, and progestogens on lipids and lipoproteins were obtained in 556 postmenopausal women aged 24 to 85 years with follow-up for 1 to 44 years. Baseline values were obtained in 155 women from less than 1 year up to 30 years after menopause. Total cholesterol and low-density lipoprotein cholesterol tended to rise during the early postmenopausal years while high-density lipoprotein cholesterol did not change. Triglycerides were related to weight and were significantly different only between untreated women of normal weight (128.3 +/- 7.80 mg/dl) and hormone users weighing greater than 200 pounds (252.9 +/- 9.44 mg/dl), p less than or equal to 0.001. Although mean high-density lipoprotein cholesterol was lower with both C-21 progestogens (64.5 +/- 4.16 mg/dl) and C-19 progestogens (61.9 +/- 3.84 mg/dl), there were no statistically significant differences on comparison with levels in the unopposed estrogen users (67.0 +/- 3.94 mg/dl). Smoking significantly depressed high-density lipoprotein cholesterol in both hormone users (p less than or equal to 0.001) and untreated women (p less than or equal to 0.001). Added progestogens do not adversely affect lipids and lipoproteins over the long term when adequate dosages of estrogens are used.
On pain mechanisms in cluster headache. Various possible pathophysiological mechanisms to explain the pain in cluster headache are reviewed. Several locations for the initiation of pain along the primary afferent pathways in cranial nerves are discussed, together with the local mechanisms that might be responsible. These include neurogenic inflammation of large cranial vessels, irritation of vascular pain fibres by compression of dilated vessels in bony canals, and irritative foci in or around cranial sensory ganglia. In particular, recent neuroanatomical and pharmacological findings on nociceptive innervation of the intracranial segment of the internal carotid artery are commented upon. The possibilities for referred pain to explain the location of pain is illustrated. Evidence for involvement of central pain modulatory systems in the pain production is discussed. Finally a synthesis is made of the probable peripheral and central pain mechanisms in the disease.
Long-term diet modification and platelet activity. Platelet activity was assessed in a sub-sample of 56 participants in the MRC Diet and Reinfarction Trial (DART). Men whose diets contained a high ratio of polyunsaturated to saturated fatty acids (a P:S ratio of greater than 0.5) showed reduced secondary platelet aggregation to adenosine diphosphate (ADP) in platelet-rich plasma (PRP), and diminished platelet aggregation to ADP in whole blood. A trend of reduced secondary platelet aggregation to ADP with increasing dietary eicosapentaenoic acid was noted, but this was not statistically significant. The results of this study and the MRC Diet and Reinfarction Trial suggest a mediatory role for platelet activity in the relationship between diet and ischaemic heart disease.
Transfer from ophthalmology to another service is a marker of high risk medical events. Of 3632 consecutive admissions to the Wilmer Ophthalmological Institute between July 1, 1987 and June 30, 1989, 27 patients required transfer to a medical or surgical service (0.74%). The major reasons for transfer included acute or decompensated cardiac disease (26%), poorly controlled diabetes mellitus (19%), acute renal failure (11%), coagulopathy, stroke, and hypertension (7% each). Only one transfer was a direct result of an anesthesia complication. The highest rates of transfers were associated with orbital (4.3%), enucleation/evisceration (3.1%), and glaucoma (2.3%) surgeries, while vitreoretinal surgery had the lowest rate of transfer (0.3%). Most of the transfers of patients with orbital disease were for management of related problems such as sinusitis or increased intracranial pressure.
New pathologic observations in juvenile onset parkinsonism with dystonia. A patient with hereditary juvenile onset parkinsonism with dystonia died at age 39. There were Lewy bodies and regionally selective neuronal damage in the substantia nigra pars compacta. These changes closely resemble those seen in Parkinson's disease, and emphasize the selective vulnerability of the ventral tier of the pars compacta in these degenerations.
Kindling as a model of drug-resistant partial epilepsy: selection of phenytoin-resistant and nonresistant rats. Complex partial seizures comprise the major uncontrolled seizure type in adult patients with epilepsy. Any improvement of our understanding of the mechanisms through which these seizures are often refractory to antiepileptic drugs is therefore of considerable importance. By examining the effects of the anti-epileptic drug phenytoin in a large group of kindled rats, a widely used model of complex partial seizures, animals with different sensitivity to this drug were selected. Using determination of the focal seizure threshold for evaluation of phenytoin's anticonvulsant effect, most animals (about 60%) showed variable effects in response to phenytoin. However, about 20% of the animals ("phenytoin nonresponders") showed no increase in their focal seizure threshold at repeated test trials with phenytoin, and 20% ("phenytoin responders") exhibited reproducible increases in focal seizure threshold after injection of phenytoin. Phenytoin responders and nonresponders thus selected were used for subsequent experiments. The different response of focal seizures to phenytoin was not related to differences in pharmacokinetics or location of the stimulating electrode. Although phenytoin reproducibly increased the threshold for induction of afterdischarges in responders, it did not alter severity or duration of the elicited seizure response. In contrast to phenytoin, carbamazepine induced increases in focal seizure threshold in all kindled rats. Duration of seizures and afterdischarges were significantly reduced by carbamazepine in phenytoin responders, but not in nonresponders, although plasma levels of carbamazepine were the same in both groups. The difference in response of kindled rats to phenytoin was restricted to kindled seizures, because phenytoin induced the same anticonvulsant effect on the threshold for generalized tonic electroconvulsions (determined via transauricular electrodes) in both groups of kindled rats.
Xanthoma disseminatum: a case with extensive mucous membrane involvement. A 37-year-old man had red or brownish papules on his face, chest, and groin, where they coalesced into plaques. Endoscopic examination revealed the presence of small xanthomatous papules on the mucous membrane of the stomach. A biopsy specimen revealed a dense infiltrate of histiocytes, foam cells, Touton giant cells, and inflammatory cells. The diagnosis of non-X histiocytosis was confirmed by immunohistochemical studies of the infiltrate.
Effect of infarct location on myocardial salvage assessed by technetium-99m isonitrile. To investigate the influence of infarct location on myocardial salvage, technetium-99m isonitrile was injected into 43 patients with a first myocardial infarction before early reperfusion therapy. Primary coronary angioplasty was performed in 22 patients and successful intravenous thrombolytic therapy was given to 15 patients, both within 6 h of the onset of chest pain. Patency of the infarct-related artery was confirmed by angiography in all 37 patients. In the remaining six patients (three with and three without early thrombolytic therapy) the infarct-related artery remained occluded. Single photon emission computed tomography was performed within 6 h of the administration of technetium-99m isonitrile and repeated at the time of hospital discharge. Radionuclide ejection fraction at discharge was significantly lower for patients with anterior infarction (0.41 +/- 0.12) than for those with inferior infarction (0.56 +/- 0.09, p less than 0.001). Early perfusion defect size, a measure of myocardium at risk, was greater in patients with anterior than in those with inferior infarction (52 +/- 9% vs. 18 +/- 10% of the left ventricle, p = 0.0001) as was final defect size (30 +/- 20% vs. 9 +/- 8%, p less than 0.01). The change in myocardial perfusion, an estimate of myocardial salvage, was also greater in patients with anterior infarction (24 +/- 16% vs. 10 +/- 7%, p less than 0.01). However, the proportion of jeopardized myocardium salvaged (salvage index) was not significantly different between patients with anterior or inferior infarction (0.49 +/- 0.34 vs. 0.59 +/- 0.35, p = NS).
Comparative clinical trial of standard operative tracheostomy with percutaneous tracheostomy. OBJECTIVE: To compare percutaneous tracheostomy with conventional operative tracheostomy. DESIGN: Randomized clinical trial. SETTING: The medical and surgical critical care units of a large, tertiary-care, private hospital. PATIENTS: Twenty-five male and 21 female translaryngeally intubated patients with respiratory failure, in whom tracheostomy was indicated on clinical grounds, were randomly assigned to one of two groups. INTERVENTIONS: The 24 patients in group 1 underwent conventional operative tracheostomy, and the 22 patients in group 2 underwent percutaneous tracheostomy. One patient in group 2 required tracheostomy on three separate occasions during a prolonged hospital stay. MEASUREMENTS AND MAIN RESULTS: Patients were examined daily throughout their hospital stays for adverse events related to the tracheostomy. In all patients who survived until decannulation, plain tomography of the trachea was performed within 3 days of decannulation. Repeat physical and tomographic examinations were performed 6 and 12 wks later. Fifty-eight percent (14/24) of the operative tracheostomies were associated with at least one complication, compared with 25% (6/24) of the percutaneous tracheostomies (p less than .05, 95% confidence interval 7% to 59%). Predecannulation problems were more frequent in group 1 patients than in group 2 (46% vs. 13%, respectively; p less than .01, 95% confidence interval 9% to 57%), as were later sequelae (88% vs. 27%; p less than .05, confidence interval 26% to 96%) in survivors. Group 1 patients were more likely to have multiple complications, and their complications tended to be more serious. CONCLUSION: In this study, percutaneous tracheostomy appeared to be superior to the conventional operation.
Generalized pustulation as a manifestation of the anticonvulsant hypersensitivity syndrome. BACKGROUND.-The anticonvulsant hypersensitivity syndrome is characterized by the development of fever, rash, lymphadenopathy, and hepatitis, and is associated with leukocytosis and eosinophilia. This article describes the unusual development of a follicular pustular eruption in two patients as a manifestation of this syndrome. OBSERVATIONS.-This pustular eruption most commonly develops on the face and scalp but may subsequently become generalized. While cultures of the pustules are negative, biopsy specimens reveal a dilated follicular infundibulum filled with neutrophils. Recognition of cutaneous pustulation as a potential manifestation of this syndrome is important, as a generalized pustular eruption developing in a febrile patient can easily be confused with an infectious process. CONCLUSIONS.-The anticonvulsant hypersensitivity syndrome may present with a follicular pustular eruption rather than the more commonly associated macular or papular rash or erythroderma. The three most commonly used anticonvulsants, phenytoin, phenobarbital, and carbamazepine, can each produce an identical hypersensitivity reaction. In addition, in vitro testing has demonstrated that approximately 80% of patients tested to all three medications had positive reactions to each. Furthermore, with in vitro testing researchers are able to predict which anticonvulsants are safe to use, thereby allowing for prospective individualization of therapy. However, this technology is not yet available for widespread use.
Solid and cystic pancreatic tumors. Clinical, histochemical, and electron microscopic features in ten cases. Ten cases of the rare solid and cystic pancreatic tumors are presented. All except one occurred in young women (mean age, 25 +/- 9.2 years). The large neoplasms were evenly distributed across the pancreas; in one case, metastasis occurred; all other cases were free from disease after complete resection. Histologic hallmarks of solid and cystic neoplasms were papillary growth, large intracytoplasmic granules, and immunoreactivity with alpha 1-antitrypsin, alpha 1-antichymotrypsin, phospholipase A2, and neuroendocrine markers (neuron-specific enolase [NSE], synaptophysin). This suggests both endocrine as well as exocrine differentiation.
Transesophageal echocardiography. Preliminary results in patients with traumatic aortic rupture. Eleven patients with blunt chest trauma at risk for traumatic aortic rupture underwent transesophageal echocardiography to image the descending aorta. Diagnoses were compared with the results of radiographic studies. Ten of the 11 patients underwent arch aortography, with positive results in six cases. In one patient, the results of a computed tomographic scan were interpreted as consistent with aortic rupture. The results of transesophageal echocardiography were positive for ruptured descending aorta in three of six patients with positive aortographic findings, and negative in eight patients. All three patients with positive findings had the diagnosis of ruptured descending aorta confirmed at surgery. The remaining eight patients demonstrated no aortic morbidity. These preliminary findings suggest that transesophageal echocardiography is a useful technique for the diagnosis of ruptured descending aorta following blunt chest trauma.
Allergic fungal sinusitis: problems in diagnosis and treatment. Although first described in 1983, allergic Aspergillus sinusitis (AAS) has yet to gain wide recognition among otolaryngologists and pathologists. We have treated three patients with a history of asthma, nasal polyposis, and recurrent pansinusitis who fit the description of allergic Aspergillus sinusitis. Histopathologically, mucinous material with abundant eosinophils and Charcot-Leyden crystals ("allergic mucin") is interspersed with fungal hyphae. Immunologic characteristics include serum total immunoglobulin E (IgE) elevation, increased RAST classes, and cutaneous reactivity to molds. A retrospective analysis of the histopathology of 82 patients with chronic sinusitis was also undertaken. Eleven additional patients with classic allergic mucin were identified, but were found to be without evidence of fungal elements. The clinical features of all 14 patients are reviewed revealing the spectrum of disease. The difficulties of diagnosis and a therapeutic protocol which includes wide local debridement and postoperative use of systemic steroids are discussed.
The use of albumin in clinical practice. The use of albumin in the clinical setting continues to generate controversy. Periodic shortages and the high cost of albumin have compelled many hospitals to develop guidelines regarding albumin administration. Our purpose is to review the human studies involving albumin. Particular emphasis will be placed on comparative trials involving albumin and the less expensive crystalloid solutions. It is hoped that this review will assist the clinician in making judgements concerning the appropriate use of albumin.
Surgical management of the conal (supracristal) ventricular septal defect. Surgical management of the conal (supracristal) ventricular septal defect differs significantly from the management of the perimembranous (infracristal) ventricular septal defect. The absence of a portion of the conal septum can lead to prolapse of the right cusp of the aortic valve, which predisposes these patients to aortic insufficiency. Between January 1980 and December 1989, 36 children with conal ventricular septal defect underwent intracardiac repair. Diagnosis was by echocardiography, cardiac catheterization, and intraoperative exploration. Preoperative evaluation showed that 26 patients (72%) had aortic valve prolapse and 16 (44%) had aortic insufficiency. Pulmonary-to-systemic flow ratios ranged from 1:1 to 3.5:1 (mean 2.0:1.0). Ten patients (27%) were believed to have clinical congestive heart failure. Age at the time of operation ranged from 2 weeks to 18 years (mean 5.5 years). Operative exposure was through the pulmonary artery (26), aorta (4), right ventricle (3), or right atrium (3). Simultaneous aortic valve suspension for aortic insufficiency was performed in four patients. Operative survival was 100%. Follow-up is complete in all patients and ranges from 0.5 to 9 years (mean 4.3 years). All patients are in normal sinus rhythm. No residual ventricular septal defects have been identified. Twenty-three of 36 patients (64%) have no evidence of aortic insufficiency; 12 of 36 (33%) have trivial or mild aortic insufficiency. One patient with initial severe aortic insufficiency underwent repeat aortic valvuloplasty 3 years after ventricular septal defect closure and aortic valve suspension. No patients have required aortic valve replacement. Surgical management of the conal ventricular septal defect differs from that of the perimembranous ventricular septal defect in two critical aspects. The operative approach should be through the pulmonary artery. This allows the best exposure of the remaining conal septum and the pulmonary and aortic valve leaflets, facilitating closure of the defect without injury to the valves or conduction system. Conal ventricular septal defects should undergo early closure, regardless of shunt volume, to prevent progressive aortic insufficiency.
Characteristics and outcomes of hospitalized older patients who develop hypocholesterolemia. OBJECTIVES: This research project was undertaken to determine the clinical characteristics, lipoprotein abnormalities, and outcomes of older hospitalized patients who develop hypocholesterolemia. METHODS: The project had two parts: (1) a retrospective, case-control study of 50 hospitalized patients greater than or equal to 65 years old whose serum cholesterol was normal on admission (greater than or equal to 160 mg/dL) and fell to less than or equal to 120 mg/dL during hospitalization; (2) a laboratory study of lipoproteins in 17 hospitalized patients greater than or equal to 65 years old whose cholesterol was normal on admission but fell to less than or equal to 120 mg/dL during hospitalization. RESULTS: Case-control Study--Nine percent of patients greater than or equal to 65 years old developed hypocholesterolemia while in the hospital, and these patients were more likely than controls to have undergone surgery and to have nothing by mouth for 5 days or longer. Cases had a longer length of stay, more complications, and were slightly more likely to die in the hospital than controls. LABORATORY STUDY--Hypocholesterolemic patients had low concentrations of all lipoproteins (VLDL, LDL, HDL), and the LDL and HDL were enriched in triglyceride and depleted of cholesterol ester. CONCLUSION: Acquired hypocholesterolemia is a common finding in hospitalized older patients and is associated with poor outcomes. Patients who became hypocholesterolemic in the hospital had both a low concentration of lipoprotein particles and abnormalities in lipoprotein particle composition.
Rate and incidence of capsular contracture: a comparison of smooth and textured silicone double-lumen breast prostheses. Capsular contracture results in dissatisfaction and deformity among the 2 million women who have had silicone implants. The literature describes contracture rates as high as 74 percent. I present a comparison of rates and incidences of contracture in patients augmented with smooth and textured double-lumen silicone implants. A total of 165 "smooth" and 63 "textured" implant patients were included in this study, which spans 12 years, 1978-1990. All patients underwent bilateral aesthetic augmentation performed by the same surgeon. Of the 165 smooth implant patients, 74 (44.8 percent) experienced contractures requiring treatment. Of the 63 textured implant patients, 3 (4.8 percent) previous contracture patients experienced sudden fibrosis within 3 months. All others remained soft. It appears that deeply textured silicone surfaces delay or decrease the rate and incidence of clinical capsular contracture, at least for 2 years.
Effects of enoximone on exercise tolerance in patients with mild to moderate heart failure. To evaluate the efficacy of enoximone on exercise tolerance in patients with mild to moderate heart failure, 33 patients underwent cardiopulmonary exercise tests before and 3 hours after placebo or after receiving 25 or 100 mg of enoximone administered randomly in a double-blind manner. The electrocardiogram was monitored and blood pressure measured every minute throughout cycle ergometer exercise testing with a ramp protocol in which the work rate increased 1 W every 6 seconds after a 4-minute 20-W warm-up. Minute ventilation, oxygen uptake (VO2), and carbon dioxide output were measured every 10 seconds in order to determine anaerobic threshold (AT) and peak VO2. Five patients were excluded from evaluation before breaking the double-blind key because of insufficient data. Heart rate increased and systolic blood pressure decreased throughout the testing only in the group taking 100 mg (n = 10). Significant increases in AT (14.4 to 16.2 ml/min/kg) and peak VO2 (20.8 to 22.9 ml/min/kg) were observed in the group taking 100 mg. The increases in AT showed a dose response, namely +0.7% in the placebo (n = 9), +6.9% in the 25-mg (n = 9) and 12.5% in the 100-mg group. The work rates at the AT point increased in the 25- and 100-mg groups. These results indicate that a single oral administration of enoximone improves exercise tolerance in patients with mild to moderate heart failure.