shukoor65/lab-rag-model huggingface dataset:
Parasympathetic withdrawal is an integral component of autonomic imbalance in congestive heart failure: demonstration in human subjects and verification in a paced canine model of ventricular failure. Although enhanced sympathetic tone is a well recognized component of the autonomic profile characteristic of congestive heart failure, the contribution of parasympathetic withdrawal to this autonomic imbalance is less well described. The technique of spectral analysis of heart rate variability provides a dynamic map of sympathetic and parasympathetic tone and was thus used to define the nature of sympathetic-parasympathetic interactions in humans with idiopathic dilated cardiomyopathy and in a paced canine model of congestive heart failure. Humans with cardiomyopathy were found to have an augmentation of the sympathetically mediated low frequency area of the power density spectrum. Parasympathetic withdrawal was demonstrated by significant reductions in the parasympathetically mediated high frequency area (p less than 0.05) and the ratio of high to low frequency areas (p less than 0.01). Administration of atropine to normal subjects resulted in a significant reduction in the high frequency area (p less than 0.05) and the high/low frequency area ratio, both of which decreased within the range noted in patients with congestive heart failure. Administration of isoproterenol in normal subjects led to an augmentation of the low frequency area but to only a small decrease in the high/low frequency area ratio. Induction of congestive heart failure in a paced canine model resulted in alterations in the autonomic profile that resembled those seen in humans with ventricular failure. The prominent high frequency region of the spectrum at baseline, indicating a predominance of parasympathetic tone, was absent after the evolution of congestive heart failure, and there was a marked augmentation of the low frequency region of the spectrum.
Analysis of morbidity and mortality rates in right hepatectomy with the preoperative APACHE II score. Morbidity and mortality rates in 70 patients who underwent major liver resection for liver tumors (primary and metastatic) were determined and correlated with the preoperative APACHE II score. Patients were divided into three groups according to their preoperative APACHE II score: low (0 to 3), mid (4 to 7), and high (8 and above). A higher score was closely correlated with increased postoperative morbidity and operative mortality rates. The group with low scores had a postoperative morbidity rate of 34% and a mortality rate of 0%, the group with mid scores had a postoperative morbidity rate of 54% and a mortality rate of 3%, and the group with high scores had a postoperative morbidity rate of 80% and a mortality rate of 20%. Age did not correlate with morbidity. It was therefore postulated that morbidity and mortality rates were related to the combination of points for abnormal physiologic variables and points for chronic health, or APACHE II score minus points for age. As the combination of these points increases the postoperative morbidity and operative mortality rates increase significantly (from 24% in the 0-point group to 69% in the greater than or equal to 3-point group). Also the two deaths occurred in the group with 3 or more points. The preoperative APACHE II score may be used by clinicians to evaluate before surgery the risk of postoperative morbidity and death in elective major liver surgery.
Comparison of effects of thrombolytic therapy on left ventricular function in patients over with those under 60 years of age. This study examined the effect of age on left ventricular (LV) function, assessed by contrast ventriculography 3 weeks after a first acute myocardial infarction in 312 patients who received thrombolytic therapy within 4 hours of the onset of infarction and in 83 patients who received placebo. Streptokinase was given to 188 patients and recombinant tissue-type plasminogen activator (rt-PA) to 124. Patients were divided into 2 age groups: less than 60 years (n = 244) and greater than or equal to 60 years (n = 151). Thrombolytic therapy improved ejection fraction in both age groups: from 54 +/- 13 to 59 +/- 11% (p = 0.021) in the younger group and from 50 +/- 14 to 57 +/- 13% (p = 0.004) in the older group. Ejection fraction was identical in streptokinase- and rt-PA-treated patients. Multifactor analysis of variance revealed that younger age and thrombolytic therapy were independently associated with improved ejection fraction. Thrombolytic therapy also reduced end-systolic volume (p = 0.001) by 14 ml in the elderly and 9 ml in the younger group. Minor bleeding complications were more frequent in the elderly and 3 serious hemorrhages occurred in patients greater than or equal to 60 years. These findings reveal that thrombolysis improves LV function in all age groups studied. Because increasing age is independently associated with a lower ejection fraction after acute myocardial infarction, thrombolytic therapy may confer greater benefits in older patients.
Dose-related effects of isoflurane associated with low plasma concentrations of verapamil on global and regional function in normal and compromised canine myocardium. Global and regional myocardial functions were studied in seven open-chest dogs with constant low plasma concentrations of verapamil as increasing concentrations of isoflurane (0.75, 1, 1.5 MAC) were administered in the presence of normal myocardial perfusion and after application of critical constriction of the left anterior descending coronary artery. In the presence of verapamil, increases in isoflurane concentrations caused dose-dependent myocardial depression both before and after critical coronary constriction. The systemic and coronary vasodilatation associated with high concentrations of isoflurane did not occur in the presence of verapamil. The association of verapamil with isoflurane caused regional myocardial dysfunction that worsened at high isoflurane concentrations. This regional dysfunction could not be antagonized in two dogs. The effects of isoflurane on regional function were not modified by application of a critical coronary constriction.
Intermittent long-term adrenocorticosteroid treatment of myasthenia gravis. It is widely accepted that a long-term, alternate-day administration of adrenal corticosteroids after thymectomy is one of the most effective treatments of myasthenia gravis. However, some patients with myasthenia gravis show a tendency to develop steroid dependency, and require extremely prolonged administration of fairly high doses of steroids. Various types of adverse reactions to steroids are likely to occur in such cases. To avoid this, intermittent, single-dose administration of steroids was performed on a trial basis in the present study. Prednisolone, in doses of 50-100 mg, was given once every 3-7 days in three steroid-dependent myasthenic patients, in one case for up to 6 years. The effects of the intermittent treatment were as good as, and adverse effects less frequently found than in single-dose, alternate-day administration.
Parathyroid hormone-related protein of malignancy: immunohistochemical and biochemical studies in normocalcaemic and hypercalcaemic patients with cancer. Immunohistochemical staining for parathyroid hormone-related protein was performed in 27 tumours from 19 normocalcaemic and eight hypercalcaemic patients with cancer. All the tumours from hypercalcaemic patients stained positively for the protein, as did 17 tumours from normocalcaemic patients. Only hypercalcaemic patients had biochemical evidence of increased bone resorption and abnormalities of renal tubular reabsorption of calcium and phosphate, consistent with the presence of parathyroid hormone-related protein. While tumour mass was higher in hypercalcaemic patients, only one of the initially normocalcaemic patients with positively staining tumours subsequently went on to develop hypercalcaemia and more advanced disease. These data confirm the importance of parathyroid hormone-related protein as a mediator of humoral hypercalcaemia in patients with solid tumours and suggest that low tumour mass may be one reason why serum calcium values are not increased in all patients with tumours containing parathyroid hormone-related protein. None the less normocalcaemia, despite tumour progression in patients whose tumours stained positively for parathyroid hormone-related protein, suggests that other factors may also be important, such as differences in the rate of secretion of the protein by different tumours, or the production of different forms of parathyroid hormone-related protein with varying biological effects.
Association of sebaceous gland tumors and internal malignancy: the Muir-Torre syndrome. The Muir-Torre syndrome (MTS) is an autosomal dominant genodermatosis characterized by: (1) at least a single sebaceous gland tumor (either an adenoma, an epithelioma, or a carcinoma) and (2) a minimum of one internal malignancy. To date, 120 patients with MTS have been reported. The most commonly associated neoplasms were colorectal (51%) and genitourinary (25%). Unlike colorectal neoplasms in the general population, the majority (58%) of these tumors in MTS patients occurred proximal to or at the splenic flexure. Nearly half of the MTS patients had more than one primary malignancy. Cutaneous lesions occurred before or concurrent with the diagnosis of the initial cancer in 41% of these patients. The median age for the appearance of the skin lesions was 53 years (range, 23 to 89 years); the median age for the detection of the initial visceral neoplasm was 50 years (range, 23 to 81 years). The cancers appear to have an indolent course in many of the MTS patients; the median survival has not been reached and the median follow-up is 10+ years. Patients with an MTS-associated cutaneous lesion should have a complete evaluation for gastrointestinal or genitourinary cancers. Although the penetrance of this disease is variable, its autosomal dominant inheritance suggests that relatives should be examined for sebaceous gland tumors and internal malignancy.
Lymphoproliferative disorders of the thyroid gland: radiological appearances. Images of lymphoproliferative disorders of the thyroid by ultrasonography (US), computed tomography (CT), 99Tcm and 67Ga scintigraphy were analysed in eight patients (two men and six women, aged 42-83 years). Seven patients were diagnosed as having primary lymphoma and one plasmacytoma. Ultrasound revealed a solid mass with homogeneous and very low echogenicity clearly distinguishable from residual thyroid tissue in five patients, diffuse hypoechoic goitre in one and multiple irregular hypoechoic nodules in both lobes in the patient with plasmacytoma (Case 8). Computed tomography demonstrated a focal low-density area in six cases of lymphoma and decreased density throughout the gland in the other two patients. 99Tcm scintigraphy showed hemilobar enlargement with decreased and uneven trapping, cold area or complete lobar defect in six patients with lymphoma and no trapping in the case of plasmacytoma. 67Ga scintigraphy demonstrated high accumulation in lymphoma and faint accumulation in the case of plasmacytoma. Radiological manifestations with a focal lesion were considered typical and diagnostic of primary thyroid lymphoma, while in one case with diffuse infiltration through the whole gland, the differential diagnosis from Hashimoto's thyroiditis could not be made. In the final case, cells infiltrated diffusely to form islands with patchy distribution among well preserved follicles, correlating with the multiple hypoechoic areas observed by US.
Diagnosis of mitral valve aneurysm by transoesophageal echocardiography. In a patient with mitral valve aneurysm precordial echocardiography suggested a mistaken diagnosis of infective endocarditis. Transoesophageal echocardiographic examination established the correct diagnosis, which was subsequently confirmed at operation. Transoesophageal echocardiography gives better resolution of lesions associated with the mitral valve than precordial examination and may improve the diagnostic accuracy.
Inhibition of entry of HIV-1 in neural cell lines by antibodies against galactosyl ceramide. Although the CD4 molecule is the principal cellular receptor for the human immunodeficiency virus (HIV), several CD4-negative cell lines are susceptible to infection with one or more HIV strains. These findings indicate that there are alternate modes of viral entry, perhaps involving one or more receptor molecules. Antibodies against galactosyl ceramide (galactocerebroside, or GalC) inhibited viral internalization and infection in two CD4-negative cell lines derived from the nervous system: U373-MG and SK-N-MC. Furthermore, recombinant HIV surface glycoprotein gp120 bound to GalC but not to other glycolipids. These results suggest a role for GalC or a highly related molecule in HIV entry into neural cells.
Listeria monocytogenes infections in patients with AIDS: report of five cases and review. Five patients with AIDS and Listeria monocytogenes infection (three cases of bacteremia and two of meningitis) are reviewed. Four patients had prior or concurrent gastrointestinal illness. Two patients received corticosteroids. A 7- to 21-day course of ampicillin was administered with or without a 7- to 14-day course of gentamicin. This regimen was effective, with no evidence of relapse 7-8 months after therapy was discontinued. The relative infrequency of infection with L. monocytogenes in AIDS patients is unexpected. Tumor necrosis factor (TNF) appears to be essential in the inhibition of Listeria in vivo. Elevated levels of TNF in AIDS patients may be protective against listeriosis and thus help explain the low prevalence of listerial infection in this population. Nonetheless, although L. monocytogenes is an uncommon cause of illness in patients infected with the human immunodeficiency virus, it cannot be dismissed as a cause of undefined meningitis or sepsis.
Molecular and phenotypic analysis of patients with deletions within the deletion-rich region of the Duchenne muscular dystrophy (DMD) gene. Eighty unrelated individuals with Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) were found to have deletions in the major deletion-rich region of the DMD locus. This region includes the last five exons detected by cDNA5b-7, all exons detected by cDNA8, and the first two exons detected by cDNA9. These 80 individuals account for approximately 75% of 109 deletions of the gene, detected among 181 patients analyzed with the entire dystrophin cDNA. Endpoints for many of these deletions were further characterized using two genomic probes, p20 (DXS269; Wapenaar et al.) and GMGX11 (DXS239; present paper). Clinical findings are presented for all 80 patients allowing a correlation of phenotypic severity with the genotype. Thirty-eight independent patients were old enough to be classified as DMD, BMD, or intermediate phenotype and had deletions of exons with sequenced intron/exon boundaries. Of these, eight BMD patients and one intermediate patient had gene deletions predicted to leave the reading frame intact, while 21 DMD patients, 7 intermediate patients, and 1 BMD patient had gene deletions predicted to disrupt the reading frame. Thus, with two exceptions, frameshift deletions of the gene resulted in more severe phenotype than did in-frame deletions. This is in agreement with recent findings by Baumbach et al. and Koenig et al. but is in contrast to findings, by Malhotra et al., at the 5' end of the gene.
Age-specific differences in the relationship between oral contraceptive use and breast cancer. Nearly all studies have suggested that the use of oral contraceptives (OC) is not associated with the aggregate risk of breast cancer diagnosed in women aged 20-54. Because of age-specific differences in the breast cancer-parity relationship and because of age-specific differences in other breast cancer risk factors, the Centers for Disease Control reexamined data from the Cancer and Steroid Hormone Study to assess whether OC use has different effects on the risk of breast cancer at different ages of diagnosis. This was a population-based case-control study conducted in eight geographic areas in the United States during 1980-1982. In these data, the relationship between the risk of breast cancer and OC use appeared to vary by age at diagnosis. Among women aged 20-34 years at diagnosis or interview, those who had ever used OC had a slightly increased risk of breast cancer (odds ratio 1.4, 95% confidence interval 1.0-2.1) when compared with women of the same ages who had never used OC. Among these women, there were no trends of increasing or decreasing risk with any measure of OC use. Among women aged 35-44 years, there was no association between OC use and breast cancer. Among women aged 45-54 years, those who used OC had a slightly decreased risk of breast cancer (odds ratio 0.9, 95% confidence interval 0.8-1.0). Among these women, the risk estimates decreased significantly with increasing time since first and last use. Although the slightly increased risk estimates for the youngest women are compatible with findings by other investigators, the decreased risk estimates for the oldest women have not been described in as many studies. Available data provide no reasons for changes in prescribing practices or in the use of OC as related to breast cancer risk.
Isolated angiitis of the central nervous system: involvement of penetrating vessels at the base of the brain. Isolated angiitis of the central nervous system (IAC) was diagnosed in a 40-year-old Caucasian male by histological examination of a leptomeningeal biopsy specimen, and the exclusion of systemic inflammatory or infective disease. Therapy with prednisone 30 mg/day and cyclophosphamide 100 mg/day resulted in clinical and radiological improvement, which have been maintained for an 8-month follow-up period. Magnetic resonance imaging (MRI) showed lesions implicating involvement of specific penetrating vessels at the base of the brain, an unusual complication of IAC, and allowed an accurate MRI-clinical correlation.
Current status of coronary artery operation in septuagenarians. Previous reports of elderly patients undergoing coronary artery bypass grafting have not addressed the current era of aggressive percutaneous angioplasty and frequent urgent or emergent operation. To investigate this important subgroup of patients, we analyzed our recent coronary artery bypass grafting experience with patients 70 years of age or older. From January 1984 to January 1989, 121 consecutive patients in this age range underwent surgical revascularization at our institution. Overall in-hospital operative mortality (OM) was 7.4% (9/121), with 77.8% (7/9) of deaths due to cardiac causes. Serious postoperative morbidity occurred in 71.1% (86/121). Surgical priority was significantly correlated with operative mortality: for elective cases, the OM was 2.9% (2/68), but it was 8.6% (3/35) for urgent cases (p less than 0.05) and 22.2% (4/18) for emergency cases (p less than 0.05). Univariate analysis isolated the need for inotropic support, intraaortic balloon pump, reoperation, cardiopulmonary resuscitation, and emergency status as significant risk factors for OM (p less than 0.05). Multivariate stepwise logistic regression analysis identified the need for inotropic support, intravenous nitroglycerin, reoperative coronary artery bypass grafting, and hypertension as independently significant risk factors. A logistic risk equation developed from this population accurately modeled OM at the extremes of operative risk. Three (3.1%) of the 97 patients predicted to have less than 5% OM died, whereas all patients predicted by the model to have greater than 90% OM died. These results indicate that in spite of relatively high morbidity and mortality rates, elderly patients have a very acceptable operative risk in the current era of high-risk coronary artery bypass grafting. This is particularly true if elective revascularization is possible.
Minimal role of xanthine oxidase and oxygen free radicals in rat renal tubular reoxygenation injury. The role of xanthine oxidase and oxygen free radicals in postischemic reperfusion injury in the rat kidney remains controversial. Proximal tubules, the focal segment affected by ischemic renal injury, were isolated in bulk, assayed for xanthine oxidase activity, and subjected to 60 min of anoxia or hypoxia and 60 min of reoxygenation to evaluate the participation of xanthine oxidase and oxygen radicals in proximal tubule reoxygenation injury. The total xanthine oxidase in isolated rat proximal tubules was 1.1 mU/mg of protein, approximately 30% to 40% of the activity found in rat intestine and liver. Lactate dehydrogenase release, an indicator of irreversible cell damage, increased substantially during anoxia (39.8 +/- 2.3 versus 9.8 +/- 1.8% in controls) with an additional 8 to 12% release during reoxygenation. Addition of 0.2 mM allopurinol, a potent xanthine oxidase inhibitor, and dimethylthiourea, a hydroxyl radical scavenger, failed to protect against the reoxygenation lactate dehydrogenase release. Analysis of xanthine oxidase substrate levels after anoxia and flux rates during reoxygenation indicates that hypoxanthine and xanthine concentrations are in a 15-fold excess over the enzyme Km and 0.3 mU/mg of protein of xanthine oxidase activity exists during reoxygenation. Hypoxic tubule suspensions had a minimal lactate dehydrogenase release during hypoxia and failed to demonstrate accelerated injury upon reoxygenation. In conclusion, although xanthine oxidase is present and active during reoxygenation in isolated rat proximal tubules, oxygen radicals did not mediate reoxygenation injury.
The ethics of nontreatment of patients with cancers of the head and neck. There are three levels at which nontreatment decisions for patients with cancers of the head and neck might be made: not doing further diagnostic procedures when the data gained would not make a significant difference to treatment decisions; not continuing aggressive therapy when its benefits are outweighed by the ensuing burdens and harms; and, at the policy level, not providing costly aggressive therapy at all because of the number of patients with unmet, more basic needs. These three levels of nontreatment decisions are discussed in light of ethical theory, briefly introduced. Arguments are made in favor of nontreatment decisions at the two clinical levels mentioned above, but against a policy decision to ration treatment for patients with cancers of the head and neck.
Hemangiopericytoma of the lacrimal sac. Hemangiopericytomas of the orbit are rare tumors with low malignancy potential. To the authors' knowledge, only three previous cases of these tumors occurring in the lacrimal sac have been reported. The authors report a fourth case. Follow-up was obtained on the first reported case, and the patient in that case had a recurrence after 15 years. These tumors should be totally excised and followed for long periods of time.