123rc/medical_text huggingface dataset:
Exercise thallium-201 imaging in complete left bundle branch block and the prevalence of septal perfusion defects. To determine the prevalence of septal defects in a generalized referral population, the records of 93 consecutive patients with complete left bundle branch block (BBB) who underwent symptom-limited treadmill exercise testing with thallium-201 myocardial imaging over a 3-year period were reviewed. Segmental analysis of the planar thallium-201 images was performed in a blinded fashion with agreement by consensus. Computerized quantitative analysis of the images also was independently performed, and was correlated with the visual interpretations. Forty-seven patients (51%) had normal images, and 46 (49%) had defects of greater than or equal to 2 segments. In the abnormal studies, only 13 patients (14% of the total population) had septal defects, while a much higher number of patients, 33 (39%), had inferior or apical defects, or both. Coronary angiography was performed in 6 patients with septal defects: Significant narrowing of the left anterior descending coronary artery was found in 4 patients, a narrowed right coronary artery was found in 1, and normal coronary arteries were seen in the other patient. In conclusion, whereas previous studies have suggested a high percentage of false-positive septal defects in patients with left BBB, this study demonstrates a low prevalence (14%) of septal defects in a large population of unselected patients presenting for exercise thallium-201 imaging. Therefore, exercise thallium-201 imaging remains a useful procedure for evaluating patients with complete left BBB.
Changes in the basal dendrites of cortical pyramidal cells from alcoholic patients--a quantitative Golgi study. Although a variety of pathological changes have been described in the brains of chronic alcoholic patients, there have been no studies which have addressed the question of alterations in cortical neuronal dendritic arborisation. Loss of neurons from the superior frontal gyrus and shrinkage of neurons from both the superior frontal gyrus and motor cortex has been documented in chronic alcoholic patients; these areas were chosen for this study. Using a modified rapid Golgi technique the basal dendritic arborisation of layer III pyramidal neurons was compared in 15 male alcoholic patients and 15 age-matched male controls. All parameters measuring basal dendritic arborisation were significantly less in the alcoholic cases for both the superior frontal and motor cortices. Changes in the arbor are in the terminal branches, which is consistent with other models of dendritic plasticity. Such changes may explain both permanent and reversible functional deficits in chronic alcoholic patients.
Effect of neurotransmitter-selective drugs in mice selected for differential sensitivity to the hypothermic actions of ethanol. Mice selectively bred for resistance (HOT) and sensitivity (COLD) to the hypothermic effect of EtOH were tested for their hypothermic response to neurotransmitter-specific drugs and for the effect of such drugs on EtOH induced hypothermia (HT). The drugs administered were the opiate drugs morphine, levorphanol and U50488H, the dopamine agonists apomorphine, LY171535 and SKF38393, the dopamine antagonist chlorpromazine, the alpha adrenergic agonist St587, the cholinergic agonist nicotine and amphetamine, which increases the release of catecholamines. All of the drugs tested, with the exception of SKF38393 and amphetamine, induced a hypothermic response in HOT and COLD mice. SKF38393 had no effect on body temperature or HT produced by EtOH. Amphetamine caused HT at low doses and hyperthermia at high doses. COLD mice were more sensitive than HOT mice to the hypothermic effect of morphine and levorphanol, mu-opiate agonists, and U50488H, a relatively specific kappa agonist. All of the other drugs tested were approximately equally potent in HOT and COLD mice. These results suggest that the differential sensitivity of HOT and COLD mice to EtOH-induced HT may be partially mediated through genetic changes in opiate mechanisms.
Split-thickness skin grafting of the myelomeningocele defect: a subset at risk for late ulceration. The appropriate method and timing of the management of the myelomeningocele defect have prompted considerable discussion. Use of split-thickness skin grafts acutely has accomplished wound closure with low morbidity and mortality. This study was designed to address the question of long-term suitability of the technique of split-thickness skin grafting of the myelomeningocele patient. The incidence of late and/or severe skin ulceration and the presence of gibbus deformity were correlated with the method of skin closure. Long-term follow-up revealed a higher incidence of chronic skin ulceration in the split-thickness skin graft group as compared with the primary closure group. All skin breakdowns appeared in the presence of a gibbus deformity, and gibbus deformity was more prevalent in the split-thickness skin graft group. The incidence of skin ulceration and gibbus deformity was site-dependent. A thoracic or thoracolumbar myelomeningocele repair with split-thickness skin graft was significantly more likely to be complicated by skin problems than the defect in the lumbar, lumbosacral, or sacral region. This relationship was secondary to the frequency of gibbus deformity in the more cephalad defects than defects caudad. A treatment plan is outlined that is based on the primary variable of the location of the myelomeningocele and secondarily by defect size.
Effects of stress on gastric mucosal prostaglandin generation in intact, adrenalectomized, and sham-operated rats. To study the effects of (a) cold restraint stress and (b) adrenalectomy in association with cold restraint stress on gastric mucosal ulceration and prostaglandin generation, we performed two experiments. In the first, 40 rats were divided into four groups of 10 rats each: (a) unstressed and (b) stressed for 0.5 h, (c) stressed for 2 h, and (d) stressed for 4 h. In the second experiment, another 80 rats were divided into four groups of 20 rats each: (a) adrenalectomy plus cold restraint stress for 2 h, (b) adrenalectomy plus no stress, (c) sham operated plus 2 h of stress, and (d) sham operated plus no stress. In both experiments we recorded an ulcer index and measured mucosal generation of prostaglandin E2 (PGE2) and prostaglandin I2 (6-keto-PGF1a). In conclusion: (a) Cold restraint stress is associated with a time-dependent decrease in gastric mucosal PGE2 generation, but no change in 6-keto-PGF1a generation, and an increase in mucosal injury that is maximal by 2 h. (b) Adrenalectomy augments the effects of stress on mucosal injury but has no effect on prostaglandin generation; thus, the ulcerogenic effect of adrenalectomy appears to be independent of an effect on prostaglandin generation.
Evaluation of vigabatrin as an add-on drug in the management of severe epilepsy. The effects of the addition of Vigabatrin, a new anti-epileptic drug, to the therapy of 128 patients with severe medically refractory epilepsy is reported. Forty two (33%) of patients experienced side effects, which were predominantly neurotropic. In 28 (22%), the drug was withdrawn because of these side effects. The commonest side effects were drowsiness and behavioural change. The remaining 100 patients were followed for a mean of 30 weeks (range 12-75). Forty one of these patients showed a marked improvement in seizure frequency (a 50% or more reduction when compared with the pre-trial period), and nine (7%) were rendered seizure free. Apparent tolerance to the effects of the drug were noted in five patients. An exacerbation of seizures may occur if the drug is withdrawn too quickly. Vigabatrin appears to be a promising new anti-epileptic drug.
Fatty liver hepatitis (steatohepatitis) and obesity: an autopsy study with analysis of risk factors. Steatohepatitis (fatty liver hepatitis), histologically identical to alcoholic disease, occurs in some obese patients after jejunoileal bypass. A similar lesion occurs rarely in obese patients without bypass surgery, but the risk factors are poorly understood. Hepatic steatosis, steatohepatitis and fibrosis were sought in 351 apparently nonalcoholic patients at autopsy and various risk factors were evaluated. Incidence of steatosis and steatohepatitis correlated with the degree of obesity. Steatohepatitis was found in 18.5% of markedly obese patients and 2.7% of lean patients. Additional risk factors for steatohepatitis were type II diabetes, weight loss in the preterminal period shortly before death and intravenous glucose therapy in the last week of life. Severe fibrosis was found in 13.8% of markedly obese patients and in 6.6% of lean patients; this difference was largely explained by the higher prevalence of diabetes in obese groups. The risk factors defined in this study are known to be associated with abnormalities of free fatty acid metabolism. Obesity, type II diabetes and intravenous glucose therapy are associated with hyperinsulinemia, which may inhibit fatty acid oxidation. Obesity and weight loss increase the presentation of fatty acids to the liver. Similar metabolic changes may occur in obese patients after jejunoileal bypass surgery. Thus this study supports the hypothesis that fatty acids have a role in the hepatocellular necrosis found in some obese individuals.
Platelet norepinephrine and epinephrine concentration in patients with pheochromocytoma. Platelet and plasma catecholamine concentrations were determined in 17 patients with surgically proven pheochromocytoma (mean age 42.3 years); in 31 patients with borderline hypertension (mean age 35.3 years) and in 9 healthy controls (mean age 39.3 years). Both platelet norepinephrine and epinephrine were significantly increased in patients with pheochromocytoma when compared with hypertensive and control groups (P less than .001). No correlation between platelet and plasma catecholamines was detected in all studied groups. The diagnostic accuracy of platelet catecholamine in pheochromocytoma is limited since increased platelet norepinephrine was found in 35.5% and increased platelet epinephrine was found in 19.4% of patients with essential hypertension.
Diaphragmatic force and substrate response to resistive loaded breathing in the piglet. Inspiratory resistive loaded (IRL) breathing results in hypoventilation and diaphragmatic fatigue in the piglet. We studied the effects of 6 h of IRL on ten 1-mo-old piglets. The load was adjusted to increase spontaneously generated transdiaphragmatic pressure five to six times baseline. Six 1-mo-old piglets acted as controls and were identically instrumented but were not subjected to IRL. Measurements of ventilation, blood gases and pH, diaphragmatic electromyogram, force-frequency curve, blood flow, and end-expiratory lung volume were obtained hourly. Diaphragmatic muscle samples were obtained after 6 h for determination of ATP, phosphocreatine, lactate, and glycogen levels. No changes occurred in the control animals. IRL resulted in a significant decrease in ventilation, an increase in diaphragmatic EMG, onset of abdominal expiratory muscle activity, and a fall in end-expiratory lung volume by 1 h. The force-frequency curve adjusted for lung volume change fell by 20% at all frequencies of stimulation at 1 h and by 40% at 6 h. Blood flow to the costal and crural diaphragm increased by 51 and 141%, respectively. No differences were noted in ATP, phosphocreatine, lactate, or glycogen between control and IRL animals. It is concluded that submaximal spontaneous contractions of the piglet diaphragm over a 6-h period cause a substantial decrease in its maximal force-generating capacity that is not related to substrate depletion.
Rapid baroreceptor resetting in Dahl salt-sensitive rats. Dahl salt-sensitive rats rapidly become hypertensive when exposed to a high salt diet, but Dahl salt-resistant rats maintain normal blood pressure on a high salt diet. A defect in baroreceptor afferents is thought to play a key role in the low sensitivity of baroreceptor reflexes in Dahl salt-sensitive rats even in the prehypertensive stage during low salt treatment. In the present study, we tested whether differences in rapid resetting ability might contribute to differences in baroreceptor function in Dahl rats. Four groups of rats were tested: salt-sensitive and salt-resistant rats on low salt and high salt diets (0.15% and 8.0% NaCl). We compared the rapidly resetting responses of baroreceptors from each group using an in vitro preparation. Rapid resetting was assessed for each aortic baroreceptor (n = 46) by linear fit of the relation of pressure threshold and conditioning mean arterial pressure. Each group had a wide range of resetting ratios (the slope of the resetting relation). Despite higher initial pressure thresholds in salt-sensitive rats on a high salt diet, resetting ratios among the four groups were similar. Thus, the ability of Dahl salt-sensitive baroreceptors to rapidly reset is preserved, despite high dietary salt and a genetic predisposition to dysfunction. The present findings in Dahl rats reinforce the results of recent studies of rapid resetting during spontaneous and renal hypertension, which suggests that the rapid resetting process is remarkably resistant to factors that compromise baroreceptor function.
Spontaneous renal rupture during pregnancy. Spontaneous rupture of the renal parenchyma or renal pelvis during pregnancy has been previously reported in 16 cases. In the case we describe in this report, the patient initially had right flank pain and nausea for 48 hours, which progressed to severe abdominal symptoms that necessitated exploratory laparotomy. Cystoscopic placement of a ureteral stent relieved the obstruction and allowed spontaneous healing of the renal pelvis. Dilatation of the urinary collecting system commonly occurs during pregnancy. Spontaneous rupture of the renal parenchyma or renal pelvis, however, is unusual and often associated with diseased kidneys. Our case is the 8th one of spontaneous rupture of the renal collecting system with no identifiable underlying pathologic condition and the 17th case of spontaneous renal rupture overall.
Isolation of sequences that span the fragile X and identification of a fragile X-related CpG island [published erratum appears in Science 1991 Apr 26;252(5005):494] Yeast artificial chromosomes (YACs) were obtained from a 550-kilobase region that contains three probes previously mapped as very close to the locus of the fragile X syndrome. These YACs spanned the fragile site in Xq27.3 as shown by fluorescent in situ hybridization. An internal 200-kilobase segment contained four chromosomal breakpoints generated by induction of fragile X expression. A single CpG island was identified in the cloned region between markers DXS463 and DXS465 that appears methylated in mentally retarded fragile X males, but not in nonexpressing male carriers of the mutation nor in normal males. This CpG island may indicate the presence of a gene involved in the clinical phenotype of the syndrome.
Invasive squamous cell carcinoma in a patient with epidermodysplasia verruciformis. A patient with epidermodysplasia verruciformis died of intracranial invasion by squamous cell carcinoma (SCC). A biopsy of clinically normal skin had revealed perineural invasion by malignant keratinocytes. Because SCCs arising in patients with epidermodysplasia verruciformis may be biologically aggressive, it is best to excise them with careful control of the surgical tissue margins.
The natural history of thrombocytopenia associated with preeclampsia. Sixty-one of 375 women with hypertension and preeclampsia in a 48-month period had thrombocytopenia. By postpartum day 3, 90% of these women had rising platelet counts, and by day 4, 59 of 61 women had counts greater than 100,000/mm3. The two exceptions had other pathologic conditions in addition to preeclampsia. Thrombocytopenia associated with preeclampsia should resolve by postpartum day 4.
Patients with mental disorders who work. Mental illness can devastate persons intellectually and emotionally; with maintenance therapy, however, certain patients with chronic mental illnesses are capable of holding a variety of jobs. From the total population of psychiatric patients in our VA outpatient clinic, the 87 who were gainfully employed were identified to determine common factors among them. Affective disorders were the predominant diagnoses among patients who worked, while schizophrenia was more common among those who did not. Alcoholism was diagnosed in approximately 25% of working and nonworking groups.
Bilateral familial carotid body paragangliomas. Report of a case with DNA flow cytometric and cytogenetic analyses. A case study of bilateral familial carotid body paragangliomas with DNA flow cytometric and cytogenetic analyses is presented. Analysis of tumor cell nuclear DNA content by flow cytometry revealed aneuploid cell populations in both tumors. Standard cytogenetic analysis (Giemsa-banding technique used) of the right carotid body paraganglioma showed no evidence of numerical or structural abnormalities. We describe parameters currently used to "predict" biological behavior in these tumors.
Serum and tissue magnesium concentrations in patients with heart failure and serious ventricular arrhythmias. OBJECTIVE: To compare magnesium concentrations in serum and tissue from patients with heart failure. Two groups of patients were compared, those with or without serious ventricular arrhythmias. DESIGN: Consecutive enrollment. Blinded laboratory analyses. SETTING: Referral inpatient service of the cardiology division of a university hospital. PATIENTS: Twenty-three patients with idiopathic dilated cardiomyopathy and mild to moderately severe congestive heart failure (New York Heart Association functional class II to IV) were divided into two groups: 9 patients with sustained ventricular tachycardias and 14 patients without serious ventricular arrhythmias (control). INTERVENTIONS: Medications for heart failure were withdrawn 12 hours or more before study. Antiarrhythmic therapy was continued throughout the study. MEASUREMENTS AND MAIN RESULTS: The patients had skeletal muscle biopsies, myocardial biopsies, and blood sampling for the analysis of magnesium concentrations. No statistically significant differences in the mean magnesium concentrations in serum, circulating mononuclear cells, skeletal muscle, and myocardium were found when the 9 patients with ventricular arrhythmias were compared with the 14 control patients without serious ventricular arrhythmias. CONCLUSIONS: In a general, ambulatory sample of patients with heart failure, magnesium depletion in serum and tissue does not appear to occur more commonly in patients with serious ventricular arrhythmias than in patients without serious ventricular arrhythmias.
Malignancy associated with chronic empyema: radiologic assessment. Radiologic findings of six cases of malignancy associated with chronic empyema 5-39 years in duration were reviewed. Pathologic examination confirmed three B-cell non-Hodgkin lymphomas, one round-cell sarcoma, one mesothelioma, and one adenocarcinoma. Retrospective findings on plain chest radiographs suggested the occurrence of malignancy: increased radiopacity in the thoracic cavity, soft-tissue bulgings and/or unsharpness of fat planes in the chest walls, destruction of bone near the empyema, and extensive medial deviation of the calcified pleurae. Computed tomography delineated masses with soft-tissue attenuation more clearly than radiography in all cases. Magnetic resonance images of three cases were informative because empyema cavities were surrounded by low-intensity rims, and two of them showed a signal intensity different from that of necrotic tumors. Scintigraphy revealed increased uptake of gallium in all cases. Ultrasonography was useful for biopsy guidance. Every radiologist should know this entity in observation of chest radiographs obtained in patients with chronic empyema, and further radiologic assessment and aggressive biopsy are recommended if malignancy is suspected.
Deficiencies of coagulation-inhibiting and fibrinolytic proteins in outpatients with deep-vein thrombosis BACKGROUND. Isolated deficiencies of antithrombin III, protein C, protein S, and plasminogen have been implicated as a cause of deep-vein thrombosis. It is assumed that patients with recurrent, familial, or juvenile thrombosis are very likely to have such a deficiency. METHODS. We studied the prevalence of isolated deficiencies of these proteins in 277 consecutive outpatients with venographically proved acute deep-vein thrombosis, as compared with 138 age-matched and sex-matched controls without deep-vein thrombosis, and calculated the positive predictive value of a history of recurrent, familial, or juvenile venous thromboembolism for the presence of such a deficiency. RESULTS. The overall prevalence of deficiencies of any of these proteins in the patients with venous thrombosis was 8.3 percent (23 of 277 patients) (95 percent confidence interval, 5.4 to 12.4), as compared with 2.2 percent in the controls (3 of 138 subjects) (95 percent confidence interval, 0.5 to 6.1; P less than 0.05 for the comparison between groups). The positive predictive values for the presence of an isolated protein deficiency in patients with recurrent, familial, or juvenile deep-vein thrombosis, defined as the proportion of patients with the clinical finding who had a deficiency of one or more of the proteins, were 9, 16, and 12 percent, respectively. CONCLUSIONS. The cause of acute venous thrombosis in most outpatients (91.7 percent) cannot be explained by abnormalities of coagulation-inhibiting and fibrinolytic proteins. The information obtained from the medical history concerning recurrent or familial venous thrombosis or the onset of the disease at a young age is not useful for the identification of patients with protein deficiencies.
The clinical utility of carotid duplex scanning. We retrospectively compared the results of duplex scanning (DS) with contrast angiography (CAN) in the evaluation of 119 patients whose 238 carotid arteries were evaluated by both methods within a four-week period. The results of all patients were then categorized by two different definitions of severity of stenosis. Category A classified 1-29% stenosis as mild, 30-69% stenosis as moderate, and 70-99% diameter reduction as severe stenosis. Category B defined mild stenosis as 1-19% lumen diameter reduction, moderate as 20-49% stenosis, and severe as 50-99% stenosis. The findings by each classification were compared in 60 patients with hemispheric symptoms and in 59 patients with nonspecific symptoms. CAN was our "gold standard", and exhibited greater sensitivity, specificity, accuracy, and predictive values than DS. Carotid arteries with 70% stenosis were identified by DS with greater specificity, accuracy, and predictive values than were arteries with 50% stenoses. Only the sensitivity was comparable in categorizations A and B (80% and 83%). All parameters of measurement were superior in patients with hemispheric symptoms. DS alone cannot substitute for CAN in selecting patients for carotid endarterectomy because its error rate exceeded acceptable rates of complications for carotid artery surgery. The false positive rate of DS was 4%. DS failed to diagnose 7 of 19 carotid artery occlusions, 9 of 11 ulcerated plaques, 7 of 119 instances of aortic arch disease, and 13 cases of severe intracranial artery stenosis.