123rc/medical_text huggingface dataset:
Evaluation of current extrication orthoses in immobilization of the unstable cervical spine. An experiment was designed to evaluate the comparative stabilizing efficacy of several widely used semi-rigid orthoses applied to unstable fresh cadaver cervical spines subject to load. Cadaver specimens were surgically destabilized at the C4-5 segment. Lateral radiographs of the destabilized spine were obtained before and after collar placement and after the application of a 5-pound flexion force. Data analysis employing a one-way analysis of variance showed no statistically significant difference in the Necloc's, Philadelphia Collar's, or the Stifneck's ability to stabilize the cervical spine against a deforming flexion force (P greater than 0.05). They all provide translational stability while allowing angular changes to occur with application of the flexion force. The Philadelphia Collar Halo System is statistically superior to all three of the aforementioned collars in prevention of both translation and sagittal rotation (P less than 0.05).
Doxazosin therapy in the treatment of diabetic hypertension. The incidence of cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM) has not been reduced by the control of hyperglycemia alone. Hypertension and dyslipidemia may be the major determinants of macrovascular disease in these patients. With the high prevalence of hypertension in NIDDM, antihypertensive drugs are likely to be important determinants of an atherogenic lipid profile. To date, there is no completed major randomized controlled trial of antihypertensive treatment outcome in a diabetic population, and as such, drug choice for the treatment of diabetic hypertension is often based on evidence extrapolated from studies in nondiabetic groups. However, two short-term studies have assessed the effects of doxazosin antihypertensive therapy in subjects with NIDDM. Both studies showed that the significant reduction in blood pressure with doxazosin treatment was associated with favorable effects on the serum lipid profile. In one study, contrasting adverse effects of atenolol treatment on glycemic control, lipids, and lipoproteins were observed. Doxazosin therapy was associated with a trend toward correcting the disturbances of lipoprotein metabolism characteristic of NIDDM. These metabolic effects, combined with effective lowering of blood pressure by doxazosin, may be important determinants of cardiovascular disease in the long term.
Routes and incidence of communication of lumbar discs with surrounding neural structures. Several authors have previously reported the complications resulting from contact between a diagnostic or therapeutic agent injected into an intervertebral disc and neural tissue. This study was undertaken to demonstrate the common routes by which, and frequency with which this contact occurs. Of 105 cadaveric intervertebral discs studies, 15 (14%) leaked. Of the discs that leaked, 27% demonstrated contact of injected dye with the adjacent spinal nerve. The high rate of leakage may be related to the age of the cadavers. Nonetheless, the contact between substances injected into an intervertebral disc and adjacent neural tissue during discography offers an alternate mechanism of pain reproduction in an incompetent disc. It also suggests that nontoxic agents should be used for discography and that intervertebral discs should be proved competent before chemonucleolysis.
The need for quality assurance in vascular surgery. The need for quality assurance in vascular surgery can be deduced from the variability in unruptured abdominal aneurysm operative death rates in a group of patients large enough that factors influencing mortality rates other than quality of care can be controlled. Operative mortality rate for 3570 patients undergoing unruptured abdominal aortic aneurysm repair was determined for all non-Veterans Administration surgeons and hospitals in New York State from 1985 to 1987. The average annual number of aneurysm operations per surgeon was 3.6, and per hospital it was 10.2. Unruptured aneurysm repair mortality for surgeons performing 1 to 5 aneurysm operations per year was 10% whereas for surgeons performing more than 26 aneurysm operations per year it was 6% (p less than 0.0001). Unruptured aneurysm repair mortality for hospitals performing 1 to 5 aneurysm operations per year was 14% and for hospitals performing more than 38 aneurysm operations per year it was 5% (p less than 0.0001). Even when these mortality rates were adjusted for differences in patient age, severity of illness, secondary diagnoses and admission status, significant mortality rate differences persisted: 9% versus 4% for low and high volume surgeons, respectively (p less than 0.001), and 12% versus 5% for low and high volume hospitals, respectively (p less than 0.001). Surgeons who performed more than 7 aneurysm operations per year devoted more of their practice to aortic (11%) and vascular operations (52%) than did surgeons who performed 7 or fewer aneurysm operations per year (2% and 19%, respectively).
Parental presence during procedures in an emergency room: results from 50 observations. This report describes the physician-parent-child encounter during an invasive medical procedure in a pediatric emergency department. Fifty children underwent venipuncture or intravenous cannulation performed by 22 physicians and 6 nurses. The median age of the children was 12 months. Parents remained with their children during 31 (62%) of the 50 procedures. Parents were more likely to stay if they had previously stayed when this child (P = .05) or another (P = .02) had undergone a procedure. Parental decision to stay was not related to parental age, gender, race, marital status, or level of education, nor to the residents' age, gender, or level of training. Only 43% of the parents who did stay were given that option by the residents, and of those who did not stay 37% reported that physicians asked them to leave. Nonverbal cues by the residents, such as pulling the curtain closed or turning their back toward parents, were noted in 58% of the encounters in which parents did not stay. The residents and nurses indicated that parents should stay with their child for the following procedures: laceration repair, 66%; venipuncture, 58%; intravenous cannulation, 48%; arterial blood sampling, 32%; suprapubic aspiration, 20%; and lumbar puncture, 14%. In the emergency room studied, it appears that for venipuncture and intravenous cannulation, the majority of parents stay with their children. Parental decision to stay or leave is frequently made without discussion with the physician.
Albumin absorption and protein secretion by the gallbladder in man and in the pig. To study albumin absorption by the gallbladder in man, an in vitro model was first established in the pig and compared with in vivo function in the same species. Water and electrolyte transport and 125I-albumin absorption and protein secretion in vivo and in vitro were compared. Then similar in vitro studies were performed on human gallbladders obtained at surgery. The in vivo study in the pig was performed without disturbing the gallbladder except to tie a cannula in the cystic duct end. The in vitro model was identical in the pig and human gallbladders. Gallbladders were excised using a technique causing minimal injury and anoxia. They were oxygenated on both mucosal and serosal surfaces in a temperature-controlled environment. Luminal and external bath test solutions consisted of modified Ringers bicarbonate with added glucose; luminal solutions also contained 125I-albumin from different species, depending on the study. Active absorption of sodium and water occurred in both types of studies in the pig but in vivo absorption rates were considerably greater than in vitro rates. Albumin absorption in vivo was substantial; although present in vitro, the absorption of albumin was diminished relatively more than electrolyte transport rates. Protein secretion rates into the gallbladder were similar in vitro and in vivo. The results of studies in the human gallbladders in vitro were similar to the pig, except albumin absorption was greater. Some human gallbladders were obtained from control patients and some from patients with cholesterol gallstones. There were no significant differences between the two groups for any of the variables studied; however, the numbers were small and some control gallbladders were not normal gallbladders.
Trends in conserving treatment of invasive carcinoma of the breast in females. This population-based study presents trends in the treatment of node-negative invasive carcinoma of the breast in females during the 1980s in the Detroit metropolitan area. It was done to determine whether or not there has been a significant shift toward conservation of the breast from 1980 to 1987. Trend analyses of surgical treatment, tumor size, node status, year of diagnosis, age and race were performed for 13,217 patients drawn from the Metropolitan Detroit Cancer Surveillance System. A significant increase in the use of conserving the breast was observed, with younger women receiving this treatment option more often than older women. Implications for a continuing shift in the biologic findings and treatment of carcinoma of the breast are discussed.
Improved molecular diagnostics for ornithine transcarbamylase deficiency. Since the cloning of the cDNA for X-linked ornithine transcarbamylase (OTC) in 1984, diagnostic accuracy of OTC deficiency for prenatal and carrier detection has been greatly improved by the use of linkage analysis. However, the use of RFLP-based diagnosis is limited in this and in other new mutation diseases. Here we report both the use of direct mutation detection by new PCR-based techniques and our experience with linkage-based diagnosis in 18 families. We have previously reported the use of chemical mismatch cleavage to detect mutations first in amplified mRNA and then in genomic DNA of patients. This technique has now been utilized for prenatal diagnosis. Primers for specific amplification of OTC exons 1, 3, 5, 9, and 10 have been developed and been employed to map deletions of the OTC gene in two families. These primers also have been used to detect alterations in the TaqI sites found in exons 1, 3, 5, and 9. Four novel mutations of the OTC gene leading to abolition of a TaqI site in the OTC cDNA were discovered. One of these mutations is in exon 1; two lie in exon 3; and one is in exon 9. In addition, we have used the PCR products as probes to identify the exon-specific bands seen on Southern blots and to map the polymorphic BamHI and MspI sites, which are commonly used for linkage analysis. This information will facilitate the interpretation of altered band patterns seen in deletion cases and in cases of point mutations affecting restriction sites. Utilization of the appropriate combination of these molecular techniques permitted accurate diagnostic evaluations in 17 of 18 families.
Genetic differences in susceptibility to glomerular sclerosis: a role for lipids? To better understand the pathogenesis of focal and segmental glomerular hyalinosis and sclerosis (FSGHS), a variety of animal models have been developed--mainly in rats--that allow a comprehensive study of all variables involved, such as hemodynamic, genetic, and metabolic factors. In this article, we briefly review the role of lipids in the pathogenesis of FSGHS and provide evidence that "atherosclerosis of the glomerular mesangium" contributes to the ultimate histopathologic lesion of FSGHS in susceptible rat strains. Observations in a FSGHS-resistant strain revealed several characteristic features that may protect these rats against chronic renal disease such as high nephron numbers, glomerular visceral epithelial cells with a remarkable resistance to toxic injury, minimal sequestration of serum proteins and cholesterol from the circulation into the mesangium, and a remarkable lipoprotein profile in normal as well as nephrotic states with a very low cholesterol content of the very-low-density and low-density lipoprotein fractions. Recent clinicopathologic studies also indicate a correlation between hyperlipidemia and the progression of renal disease. The concept of lipid-mediated glomerular injury warrants further study.
Visuospatial impairment in Parkinson's disease. We explored the nature of the visuospatial deficit in Parkinson's disease (PD) and its progression as a function of disease duration. We compared the performance of 183 patients with idiopathic PD and 90 control subjects matched for age and education on six visuospatial measures. We divided patients into three groups according to the disease duration: early (1 to 4 years), middle (5 to 10 years), and advanced (greater than 10 years). Performance deteriorated in five of the six visuospatial measures, as a function of disease duration. However, the pattern of visuospatial decline depended on whether dementia was present. The results were not influenced by age or anticholinergic medication. These findings support the presence of visuospatial deficits in PD patients, with a changing pattern of impairment related to dementia and progression of the disease.
Role of endothelium-derived nitric oxide in the bleeding tendency of uremia. Endothelium-derived relaxing factor, now identified as nitric oxide (NO), is a labile humoral agent formed by vascular endothelial cells from L-arginine. NO mediates the action of substances that induce endothelium-dependent relaxation and plays a role in regulating blood pressure. In this study we investigated whether NO is involved in the pathogenesis of the bleeding tendency associated with renal failure. Rats with extensive surgical ablation of renal mass develop renal insufficiency due to progressive glomerulosclerosis. Like uremic humans, rats with renal mass reduction and uremia have a bleeding tendency that manifests itself by a prolonged bleeding time. We found that N-monomethyl-L-arginine (L-NMMA), a specific inhibitor of NO formation from L-arginine, completely normalized bleeding time when given to uremic rats. L-NMMA injection also increased ex vivo platelet adhesion but did not affect ex vivo platelet aggregation induced by adenosine diphosphate, arachidonic acid, and calcium ionophore A23187. The shortening effect of L-NMMA on bleeding time was completely reversed by giving the animals the NO precursor L-arginine, but not D-arginine, which is not a precursor of NO. It thus appears that NO is a mediator of the bleeding tendency of uremia.
Indium-111-antimyosin scintigraphy after doxorubicin therapy in patients with advanced breast cancer Indium-111-antimyosin (111In-antimyosin) scans were performed in 20 women with advanced breast cancer after 10 cycles of chemotherapy consisting of cyclophosphamide, 5-fluorouracil and doxorubicin (total cumulative dose of doxorubicin of 500 mg/m2). Antimyosin uptake in the myocardium was quantified by means of a heart-to-lung ratio (HLR). Antimyosin uptake in the myocardium was observed in 17/20 (85%) patients, and HLR after chemotherapy was 1.86 +/- 0.25. Left ventricular ejection fraction (EF) was determined before and after chemotherapy. Patients with decreased EF (8/20, 40%) presented with more intense antimyosin uptake (HLR of 2.11 +/- 0.10 versus 1.70 +/- 0.16 (p = 0.01]. HLR values correlated with EF values after chemotherapy (r = -0.47, p less than 0.05). Positive antimyosin studies after chemotherapy including doxorubicin, indicate the presence of myocardial damage in these patients. Antimyosin studies are a sensitive method to detect myocyte damage in patients after doxorubicin therapy.
Prospective evaluation of clinical and pathologic detection of axillary metastases in patients with carcinoma of the breast. Complete axillary dissection was performed in 287 patients undergoing modified radical mastectomy between 1984 and 1987 to identify patterns of axillary node metastases, as well as discontinuous axillary node ("skip") metastases. Positive pathologic findings were compared with preoperative clinical examinations in 266 patients and showed only 60 cases (22.6%) clinically suspicious for tumor, in contrast to 131 (45.6%) with pathologically confirmed positive lymph nodes. Axillary contents were classified level I, II, or III based on their relationship to the pectoralis minor muscle. An average of 24.2 nodes was resected per patient (level I, 10; level II, 8.1; and level III, 5.3). Tumors ranged in size from 0.5 to 12.0 cm (mean, 2.6 cm), and increasing tumor size was associated with an increased likelihood of positive nodes. The data on 204 patients with complete clinical and pathologic data show that of 119 patients with negative level I nodes a limited axillary dissection (level I only) would fail to identify 6 with positive level II and 2 with positive level III nodes, whereas of 85 patients with positive level I nodes limited axillary dissection would fail to identify 17 with positive level II nodes, 7 with positive level III nodes, and 27 with positive levels II and III nodes. Complete axillary dissection (levels I, II, and III) should be performed to stage patients accurately, as well as to remove tumor-involved nodes and diminish local axillary recurrences. Clinical examination of the axilla appears to be a poor means of identifying axillary metastatic cancer.
Value of carvedilol in congestive heart failure secondary to coronary artery disease. Despite considerable interest in the use of beta-blocking agents in congestive heart failure (CHF), their clinical application is limited because of their negative inotropic effects. Beta blockers with vasodilating properties may have the advantage of overcoming this, however. Carvedilol, a beta-blocking agent with vasodilating properties, was evaluated in 17 patients with chronic CHF secondary to ischemic heart disease with a resting left ventricular ejection fraction less than or equal to 45%, who were being maintained on diuretics. Exercise testing, radionuclide ventriculography, and right-sided cardiac catheterization were performed and intraarterial blood pressure measured before and after 8 weeks of carvedilol therapy in a dosage of 12.5 to 50.0 mg twice a day. Twelve patients completed the study and 5 withdrew. Symptomatic and hemodynamic improvement was demonstrated in 11 of the 12 patients. Heart rate and intraarterial blood pressure were both reduced by chronic therapy. Mean +/- standard deviation exercise time improved from 4.3 +/- 1.6 to 7.1 +/- 2.7 minutes (p less than 0.0001), as did resting left ventricular ejection fraction, from 27 +/- 9 to 31 +/- 11% (p less than 0.02). Pulmonary arterial wedge pressure fell from 19 +/- 7 mm Hg to 12 +/- 5 mm Hg (p less than 0.001) and total systemic vascular resistance from 1,752 +/- 403 to 1,497 +/- 310 dynes/s/cm-5/m2 (p less than 0.02). Stroke volume index improved also, from 31 +/- 6 ml to 40 +/- 6 ml (p less than 0.0005). These hemodynamic changes were mediated partly by vasodilation, diminished myocardial oxygen demand and reduction of sympathetic overactivity in the failing heart. These data suggest that carvedilol may have beneficial effects in patients with chronic CHF secondary to coronary artery disease.
Effects of bucindolol on neurohormonal activation in congestive heart failure. To examine the effects of beta-adrenergic blockade on neurohormonal activation in patients with congestive heart failure, 15 men had assessments of hemodynamics and supine peripheral renin and norepinephrine levels before and after 3 months of oral therapy with bucindolol, a nonselective beta antagonist. At baseline, plasma renin activity did not correlate with any hemodynamic parameter. However, norepinephrine levels had a weak correlation with left ventricular end-diastolic pressure (r = 0.74, p less than 0.01), stroke volume index (r = 0.61, p less than 0.02) and pulmonary vascular resistance (r = 0.54, p less than 0.05). Plasma renin decreased with bucindolol therapy, from 11.6 +/- 13.4 to 4.3 +/- 4.1 ng/ml/hour (mean +/- standard deviation; p less than 0.05), whereas plasma norepinephrine was unchanged, from 403 +/- 231 to 408 +/- 217 pg/ml. A wide diversity of the norepinephrine response to bucindolol was observed with reduction of levels in some patients and elevation in others. Although plasma norepinephrine did not decrease, heart rate tended to decrease (from 82 +/- 20 vs 73 +/- 11 min-1, p = 0.059) with beta-adrenergic blockade, suggesting neurohormonal antagonism at the receptor level. No changes in I-123 metaiodobenzylguanidine uptake occurred after bucindolol therapy, suggesting unchanged adrenergic uptake of norepinephrine with beta-blocker therapy. Despite reductions in plasma renin activity and the presence of beta blockade, the response of renin or norepinephrine levels to long-term bucindolol therapy did not predict which patients had improved in hemodynamic status (chi-square = 0.37 for renin, 0.82 for norepinephrine).
Analysis and predictors of pulmonary vascular resistance after cardiac transplantation. Elevated pulmonary vascular resistance is a known risk factor for early death from acute right ventricular failure after orthotopic cardiac transplantation. Patients in whom the elevated pulmonary vascular resistance is due primarily to increased left atrial pressure ("reactive") frequently have normalization of resistance after transplantation, but few studies have detailed the time course and magnitude of these changes. To analyze the response of pulmonary vascular resistance to cardiac transplantation, we analyzed data from 4353 right heart catheterizations on all 182 patients undergoing cardiac transplantation between 1981 and Jan. 1, 1990. Before transplantation 18% of patients had a pulmonary vascular resistance greater than 4 WU, 16% had a pulmonary artery systolic pressure greater than 60 mm Hg, and 16% had a transpulmonary gradient greater than 14 mm Hg. In the overall group of patients, pulmonary vascular resistance (mean value 2.63 WU), transpulmonary gradient (mean value 9.9 mm Hg), and pulmonary artery systolic pressure (mean value 48.0 mm Hg) were normalized within 1 week of cardiac transplantation. In patients with a high preoperative pulmonary vascular resistance (greater than or equal to 4 WU), the resistance fell promptly within 1 week of transplantation but continued to be slightly elevated throughout the period of follow-up. By multiple regression analysis, pulmonary vascular resistance at 1 week and 1 year after transplantation was significantly correlated with the pretransplantation resistance. Pulmonary vascular resistance anytime after transplantation was related to preoperative resistance, body surface area, and pulmonary artery diastolic pressure. Inferences: (1) As a group, cardiac transplant recipients have a normal pulmonary vascular resistance, transpulmonary gradient, and pulmonary artery systolic pressure within 1 week after transplantation with little change thereafter for at least several years. (2) Patients with reversible elevation of pulmonary vascular resistance before cardiac transplantation typically have a reactive and a fixed component. Cardiac transplantation relieves the reactive but not the fixed component. As a result, pulmonary vascular resistance early (within 1 week) and late after transplantation will have fallen but not completely normalized.
Intraoperative pressure profile measurement and continence mechanism adjustment in the Indiana pouch urinary reservoir. We have described herein a simple pressure transducer system which helps the surgeon to tailor suture placement and achieve a continent ileocecal reservoir. It seems that fewer Lembert sutures than previously recommended are necessary to create a continent reservoir, although further study is needed.