shukoor65/lab-rag-model huggingface dataset:
Trisomy 21: association between reduced recombination and nondisjunction. To assess the association between recombination and nondisjunction of chromosome 21, we analyzed cytogenetic and DNA markers in 104 trisomy 21 individuals and their parents. Our DNA marker studies of parental origin were informative in 100 cases, with the overwhelming majority (94) being maternal in origin. This value is significantly higher than the 75%-80% maternal nondisjunction rate typically observed in cytogenetic studies of trisomy 21 and illustrates the increased accuracy of the molecular approach. Using the maternally derived cases and probing at 19 polymorphic sites on chromosome 21, we created a genetic map that spans most of the long arm of chromosome 21. The map was significantly shorter than the normal female linkage map, indicating that absence of pairing and/or recombination contributes to nondisjunction in a substantial proportion of cases of trisomy 21.
Detection of inadvertent respiratory placement of small-bore feeding tubes: a report of 10 cases. Documented inadvertent respiratory placement of small-bore feeding tubes was identified in 10 patients over a 2-year period in five intensive care units and two general wards. Types and effectiveness of bedside methods used by clinicians to test tube position were described. The most frequently used methods were observation for respiratory distress and auscultation of the abdomen during air insufflations through the tubes. It was concluded that commonly used bedside methods to test feeding tube placement often gave false reassurance that the tubes were properly positioned.
Differences in beta-adrenergic neuroeffector mechanisms in ischemic versus idiopathic dilated cardiomyopathy. BACKGROUND. We measured the content and activities of components of the beta-adrenergic receptor-G protein-adenylate cyclase complex and adrenergic neurotransmitter levels in left and right ventricular myocardial preparations derived from 77 end-stage failing human hearts from patients with idiopathic dilated cardiomyopathy (IDC) or ischemic dilated cardiomyopathy (ISCDC). METHODS AND RESULTS. The results were compared with data obtained in 21 nonfailing hearts removed from organ donors. Compared with ISCDC ventricles, IDC left and right ventricles exhibited a greater degree of total beta- or beta 1-receptor downregulation. In contrast, compared with IDC right ventricles, isolated tissue preparations of ISCDC right ventricles exhibited a greater degree of subsensitivity to the inotropic effect of isoproterenol, indicating a relatively greater degree of functional uncoupling of right ventricular ISCDC beta-receptors from mechanical response. In addition, relative to IDC left ventricles, preparations of ISCDC left ventricle exhibited greater subsensitivity to beta-agonist-mediated adenylate cyclase stimulation, indicating functional uncoupling of left ventricular ISCDC beta-receptors from cyclic AMP generation. The uncoupling of beta-receptors in ISCDC left and right ventricles may have been a result of abnormalities in G protein activation of adenylate cyclase; compared with age- and cardiac function-matched respective left or right IDC ventricles, ISCDC left ventricles exhibited less stimulation of adenylate cyclase by NaF or forskolin but no change in Mn2+ stimulation, whereas ISCDC right ventricles exhibited less stimulation by the nonhydrolyzable guanine nucleotide Gpp (NH)p. Also, IDC right ventricles exhibited a "selective" (not present in IDC left ventricles or ISCDC ventricles) decrease in stimulation of adenylate cyclase by Mn2+. Tissue neurotransmitter levels and pertussis toxin-catalyzed ADP ribosylation were altered to similar extents in IDC and ISCDC. CONCLUSIONS. These data indicate that potentially important differences exist in the regulatory behavior of components of the beta-adrenergic receptor-G protein-adenylate cyclase complex in IDC versus ISCDC, differences that presumably relate to the distinct pathophysiologies of these two types of heart muscle disease.
Home use of rectal diazepam for cluster and prolonged seizures: efficacy, adverse reactions, quality of life, and cost analysis. From 1982 through 1987, 128 families, who were instructed in the use of rectally administered diazepam (R-DZP) for the treatment of severe epileptic seizures, were surveyed. Sixty-seven families returned questionnaires and met inclusion/exclusion criteria; the results were used to analyze the medical, psychosocial, and economic impact of this program during the first year following instruction. Twenty-six families did not use R-DZP, primarily because of patient improvement. Among families using R-DZP, a total of 428 doses were administered to 41 children. R-DZP was effective in controlling seizures in 85% of patients. Adverse reactions usually were mild, consisting of drowsiness and/or behavioral changes. Compared to the year prior to instruction, emergency room visits decreased in both R-DZP-treated and -nontreated children; however, cost-savings were greater for the R-DZP group ($1,039.00 vs $420.00 per patient per year). Improvements in quality of life associated with the availability of R-DZP were observed by 58% of users and 27% of nonusers which included improved management of their children's seizures, increased flexibility in family activities, and greater peace of mind. R-DZP appears to be a practical method in the effective treatment of severe seizures at home.
Central role of sodium in hypertension in diabetic subjects. The common association between diabetes mellitus and hypertension may be promoted by several mechanisms. Patients with insulin-dependent (type I) diabetes and prone to develop nephropathy often have a familial predisposition for essential hypertension, whereas normotensive healthy offspring of nondiabetic essential hypertensive parents tend to have a reduced insulin sensitivity and increased plasma insulin levels. Na+ retention occurs as a characteristic alteration in type I or non-insulin-dependent (type II) diabetes; exchangeable body Na+ (Naex) is increased by 10% on average. This abnormality develops in the uncomplicated stage of diabetes and differentiates diabetic from nondiabetic essential hypertensive subjects. Possible Na(+)- retaining mechanisms include increased glomerular filtration of glucose leading to enhanced proximal tubular Na(+)-glucose cotransport, hyperinsulinemia (which activates several tubular Na+ transporters), an extravascular shift of fluid with Na+, and, once it occurs, renal failure. The pathogenetic role of Na+ retention in diabetes-associated hypertension is supported by positive correlations between systolic or mean blood pressure and Naex and by normalization of blood pressure after removal of excess Na+ by diuretic treatment in hypertensive diabetic subjects. The latter may also have an enhanced sensitivity of blood pressure to Na+. Plasma levels of active renin, angiotensin II, aldosterone, and catecholamines are usually normal or low in metabolically stable type I or type II diabetes. However, an exaggerated vascular reactivity to norepinephrine and angiotensin II commonly occurs already at uncomplicated stages of type I or type II diabetes. This may be a manifestation of functional (i.e., intracellular electrolytes) and/or morphological (proliferation, narrowing, and stiffening) vasculopathy. Diabetes-associated Na+ retention, vasculopathy, and a presumably inherited predisposition for both diabetes and essential hypertension may represent important complementary factors favoring the frequent occurrence of hypertension in the diabetic population.
Detection of malignant bone tumors: MR imaging vs scintigraphy. One hundred six patients with a known or suspected diagnosis of bone cancer (11 patients with biopsy-proved primary tumors, 95 patients with metastatic disease) were evaluated with scintigraphy and MR imaging to determine the relative sensitivity of each technique in the detection of bone disease. MR imaging was performed at 0.5 T as part of the entry evaluation into Intramural Research Board protocols (30%), for evaluation of cord compression, or because of an equivocal scintigram. MR was performed with T1-weighted (e.g., 300-500/10-20 [TR/TE]), T2-weighted (e.g., 2000/80) spin-echo (SE), and a short-TI inversion recovery (STIR) pulse sequence. Scintigrams were performed with 99mTc-methylene diphosphonate. A retrospective analysis showed that in 30 (28%) of 106 patients, MR imaging performed over a limited region of interest revealed a focal abnormality consistent with tumor that was not observed on scintigraphy. Only one patient had an abnormality on scintigraphy, caused by a metastasis, that was not found on MR images. In 73 (69%) of the 106 patients, the results of MR imaging and scintigraphy were equivalent; in 41 cases results of both techniques were normal. A McNemar analysis of the discordant cases showed MR imaging to be more sensitive than scintigraphy was (p less than .001). Our results suggest that although MR imaging has a greater sensitivity in detecting focal disease, scintigraphy is still the most useful screening test for evaluating the entire skeleton. MR imaging should be reserved for clarification of scintigraphic findings when suspicion is high for tumor.
Central hypothyroidism due to isolated TRH deficiency in a depressive man. A depressive man was evaluated for developing chronic fatigue and cold intolerance, in whom laboratory findings showed decreased thyroid hormone levels (T4, 2.7 micrograms dl-1; T3, 0.76 ng ml-1) with normal blood levels of TSH. A single bolus injection of TRH (500 micrograms) significantly stimulated prolactin secretion, but did not cause an increase in blood TSH levels (basal level, 1.2 microU ml-1 vs. 1.3 microU ml-1 30 min after injection). By contrast, TRH-induced TSH stimulation occurred after repeated injection of TRH for 4 consecutive days (basal level, 1.5 microU ml-1 vs. 5.6 microU ml-1 30 min after injection). Blood thyroid hormone concentrations were restored to normal levels after long-term administration of TRH. Other pituitary functions remained unchanged. A diagnosis of central hypothyroidism due to isolated TRH deficiency was made in this case, and the data presented here indicate that partial resistance of pituitary thyrotrophs to TRH may be associated with depression.
Postoperative primary adrenal failure in a patient with anticardiolipin antibodies A 50-year-old woman with no history of thrombosis or recurrent abortions developed pulmonary thromboembolism and bilateral hemorrhagic adrenal infarction with adrenal failure after hysterectomy for uterine fibroids. Anticardiolipin antibodies (aCL) were detected in high titer and have persisted. She remains well, without further thromboses, taking steroid replacement and warfarin anticoagulation. The initial presentation of aCL related disease can be as thrombotic postoperative complications in middle-age.
Resection of malignant bone tumors about the shoulder. A preliminary report of reconstruction with a new modular spacer. Reconstruction after resection of malignant bone tumors about the shoulder is difficult. Twelve patients had reconstruction using a new titanium modular spacer. This modular system allows the surgeon to reconstruct variable lengths of the proximal humerus. Although the patient has no active shoulder motion, excellent hand and elbow function is preserved. The spacer serves as a temporary device in the young active patient. A more definitive reconstructive procedure can be performed after the completion of chemotherapy and a sufficient disease-free interval.
Congenital optic tract syndrome. We describe two patients with complete homonymous hemianopia who were unaware of their visual field defects. The clinical impression of an optic tract syndrome was confirmed by magnetic resonance imaging, which showed absence of the corresponding tract in each case. The pathogenesis of congenital absence of the optic tract is unclear but it could represent either a primary failure of development or secondary atrophy due to focal injury during the perinatal period.
CT evaluation of solitary pulmonary nodules: value of 185-H reference phantom. The pulmonary nodule CT reference phantom is widely used in the evaluation of nodules 2 cm or less in diameter. It is used to detect benign patterns of calcification that are not visible on thin-section CT scans. Since 1986, the reference nodules have been manufactured with a nominal composition of 185 H. The multicenter study published in 1986 used nodules with a nominal composition of 264 H, 100 H more than the threshold value reported by Siegelman et al. in 1980. In the multicenter study, one of 37 nodules diagnosed as benign with the phantom proved to be malignant. The purpose of this study was to determine the misdiagnosis rate with the 185-H phantom and to ascertain whether the malignant tumors predicted to be benign actually contained calcification. We retrospectively reviewed 296 cases in which examinations had been performed with the 185-H nodules since 1986. Eighty-five nodules were diagnosed as benign by comparison to the reference phantom. These 85 contained no visible calcification on thin-section CT scans. Ten of the 85 cases were shown to be malignant tumors. Eight were diagnosed as having a high probability of benignity. Two were diagnosed as having a moderate probability of benignity. Calcium was present in the tissue of all six nodules available for review. Fifty-nine of the 85 nodules were still clinically indeterminate at the time of this review. Even if all of the clinically indeterminate nodules are benign, the misdiagnosis rate would be significantly higher than in most previous studies. Although analysis by using the reference phantom with 185-H nodules may indicate a high probability of benignity, close radiologic follow-up is necessary.
Comprehensive multidisciplinary treatment of chronic pain: a follow-up study of treated and non-treated groups. There are relatively few outcome studies of multidisciplinary chronic pain programs which have utilized no-treatment comparison groups. The present study compared a group of chronic pain patients (N = 42) treated in a comprehensive multidisciplinary pain program with a group of patients (N = 15) who were evaluated but not treated. Comparisons were made at evaluation and at a follow-up period averaging 11 months later. From evaluation to discharge, the treated group showed significant increases in physical functioning. From evaluation to long-term follow-up, both the treated and non-treated groups showed significant decreases in self-report pain ratings and interference with activities ratings. However, only the treated group showed a significant decrease in addictive medication use and increase in work functioning. The return-to-work rate for the treated group was 48% with an additional 28% of the patients being returned to vocational rehabilitation. None of the non-treated group returned to work or vocational rehabilitation. Results are discussed in terms of their support for the conclusion that comprehensive multidisciplinary pain programs produce marked subjective and functional changes.
Neural processing of craniovascular pain: a synthesis of the central structures involved in migraine. In order to determine the anatomical distribution of cells concerned with relaying craniovascular nociception, local cerebral glucose utilization was determined by the 2-deoxyglucose method in tissue autoradiographs of the alpha-chloralose anesthetized cat. The superior sagittal sinus was carefully lifted from the brain by sectioning the dura laterally and the falx inferiorly and suspending the sinus across two platinum hook electrodes for stimulation. The sinus was stimulated electrically and its effect on caudal brainstem, upper cervical spinal cord and diencephalic metabolic activity determined. Stimulation of the sinus caused increased metabolic activity in the trigeminal nucleus caudalis, in the cervical dorsal horn and in a discrete area in the dorsolateral spinal cord at the second cervical segment. Metabolic activity was also increased in the ventrobasal thalamus, specifically in the ventroposteromedial (188%) nuclear group, in the medial nucleus of the posterior complex (70%) and the intralaminar complex (49%). There was no change in the surrounding thalamus, lateral geniculate nucleus or overlying cerebral cortex. These increases in 2-deoxyglucose utilisation were blocked by bilateral trigeminal ganglion ablation. The dorsolateral area activated in the spinal cord corresponds to a hitherto unrecognised group of cells in or near the lateral cervical nucleus that may form an important relay for craniovascular nociception. Further electrophysiological studies with glass coated tungsten microelectrodes have characterised the cells in these regions of the thalamus to be responsible for relaying nociceptive information. An understanding of the connections and properties of the neurons that subserve craniovascular pain is an essential prerequisite to understanding the complex pathophysiology of migraine.
Dissecting aneurysm of the posterior cerebral artery: spontaneous resolution. Dissecting aneurysms of the intracranial arteries display vascular pathological features that appear sporadically, generally affecting young adults. The clinical features of this condition may involve both ischemic episodes and hemorrhages. Posterior circulation is affected less than the rest of the intracranial arteries, and it is extremely rare to find the posterior cerebral arteries only affected. Mortality is high in patients where the lesion is located in the posterior intracranial circulation, although dissecting aneurysms limited to the posterior cerebral arteries may, to a certain extent, be benign. We report the case of a young woman with ischemia in the territory of the posterior cerebral artery that occurred subsequent to a dissecting aneurysm that resolved spontaneously to a complete remission, both clinically and as demonstrated by angiography. A review of the literature is made, analyzing the pathogenic, clinical, angiographic, and therapeutic characteristics of such lesions.
Lipid peroxidation: a possible factor in late graft failure of coronary artery bypass grafts. Atherosclerosis is the paramount cause of late vein graft failure after coronary artery bypass grafting. Lipid peroxidation, which may play a significant role in the initiation and progression of atherosclerosis, was examined in segments of vein grafts (n = 6) harvested at reoperation for coronary disease. These were analyzed for cholesterol, phospholipid, triglyceride, and lipid peroxides. Nonatherosclerotic vascular tissues, including coronary arteries (n = 6), saphenous veins (n = 9), and donor aortic specimens (n = 11) were analyzed for comparison. Risk factors for atherosclerosis including elevated serum cholesterol and triglycerides, smoking, and hypertension were more frequent in patients with coronary artery disease compared to organ donors. Lipid peroxides were elevated in explanted vein grafts when compared to either saphenous vein, coronary artery or donor aorta. Lipid peroxides were not significantly different in saphenous vein when compared to coronary artery, but levels in both of these tissues were greater than in donor aorta. Although increased levels of lipid peroxides in explanted veins may simply reflect morphologic changes in these grafts, the known effects of lipid peroxides on a number of biochemical events suggest that they may contribute directly to graft failure after coronary artery bypass grafting.
Brain and brain tumor uptake of L-3-[123I]iodo-alpha-methyl tyrosine: competition with natural L-amino acids SPECT studies with L-3-[123I]iodo-alpha-methyl tyrosine (IMT) were carried out in 10 patients with different types of brain tumors--first under fasting conditions (basal) and a week later during intravenous infusion of a mixture of naturally-occurring L-amino acids (AA load). An uptake index (UI) was calculated by dividing tissue count rates by the integral of plasma count rates. The UI decreased by 45.6% +/- 15.4% (n = 10, p less than 0.001) for normal brain and by 53.2% +/- 14.1% for gliomas (n = 5, p less than 0.01) during AA load compared to basal conditions, while two meningiomas and a metastasis showed only a minor decrease (23.9 +/- 5.7%, n.s.). Two pituitary adenomas could not be delineated on the SPECT scans. These data indicate that IMT competes with naturally-occurring L-amino acids for transport into normal brain and gliomas. Transport characteristics of IMT into tumors of nonglial origin appear to be different from those of gliomas. For both types of tumors, it is advisable to perform IMT-SPECT under fasting conditions.
The use of angioplasty, bypass surgery, and amputation in the management of peripheral vascular disease BACKGROUND. Percutaneous transluminal angioplasty has been adopted widely as a treatment for patients with peripheral vascular disease of the lower extremities. However, the effect of this procedure on the overall management of peripheral vascular disease and on the outcomes of patients has not been clearly delineated. In particular, it is not known whether angioplasty has replaced other treatments for peripheral vascular disease. METHODS. To assess the extent to which angioplasty is used and the associated changes in the surgical management of peripheral vascular disease of the lower extremities, we used data on hospital discharges in Maryland to identify all angioplasty procedures, peripheral bypass operations, and lower-extremity amputations performed for peripheral vascular disease in Maryland hospitals between 1979 and 1989. RESULTS. We estimated that from 1979 to 1989 the annual rate of percutaneous transluminal angioplasty for peripheral vascular disease of the lower extremities, adjusted for age and sex, rose from 1 to 24 per 100,000 Maryland residents (P less than 0.0001 by linear regression). Despite this increase in the use of angioplasty, the adjusted annual rate of peripheral bypass surgery also rose substantially, from 32 to 65 per 100,000 (P less than 0.001), whereas the adjusted annual rate of lower-extremity amputation remained stable at about 30 per 100,000. Total charges for hospitalizations during which a peripheral revascularization procedure was performed increased from $14.7 million in 1979 (in 1989 dollars) to $30.5 million in 1989. CONCLUSIONS. In Maryland, the adoption of percutaneous transluminal angioplasty for peripheral vascular disease of the lower extremities has been associated with an increase in the use of peripheral bypass surgery and with no decline in lower-extremity amputations. These results could be due to increased diagnosis of peripheral vascular disease, expanded indications for procedural interventions, or an increased number of repeat procedures performed in patients with peripheral vascular disease of the lower extremities.
Transethmoid decompression of the optic nerve in head injuries: an update. Sixty-three patients with loss of vision following head injury were subjected to decompression of the optic nerve by the transethmoid route. This paper discusses the criteria for selection of patients for surgery, the results of the operation and the prognostic factors determining the results.