123rc/medical_text huggingface dataset:
A comparison of neurological, metabolic, structural, and genetic evaluations in persons at risk for Huntington's disease. We compared four diagnostic data sets for the assessment of individuals at risk for Huntington's disease. Fifty-four chorea-free persons were evaluated by neurological examination, positron emission tomography measurement of glucose metabolism, radiographic computerized tomographic measurement of caudate size, and genetic testing at the polymorphic DNA loci D4S10, D4S43, and D4S125. Twelve (22%) persons had abnormal caudate metabolism, 6 (11%) had subtle abnormalities of motor control, and 7 (13%) had computed tomographic evidence of caudate atrophy, compared with an expected gene frequency of 34% for this population. In 20 persons with unambiguous genetic test results or the subsequent phenotypic expression of Huntington's disease (chorea), there was a greater sensitivity of the positron emission tomographic measurement of caudate metabolism (75%) relative to computed tomography (33%) or the clinical examination (17%) for the determination of a subpopulation of probable Huntington's disease gene carriers. Hypometabolism of the putamen and globus pallidus, and hypermetabolism of the precentral gyrus were also associated with a high probability of carrying the Huntington's disease gene. The findings support the hypothesis that abnormalities of cerebral metabolism precede clinical or structural (computed tomographic) abnormalities in gene-positive individuals at risk for Huntington's disease.
Mutations in src homology regions 2 and 3 of activated chicken c-src that result in preferential transformation of mouse or chicken cells. src homology regions 2 and 3 (SH2 and SH3) of proteins encoded by src and closely related genes are conserved domains believed to modulate the protein-tyrosine kinase activity of this class of proteins, perhaps through interactions with other proteins. To explore the possibility of using src mutants as probes for such interactions, we have compared mouse NIH 3T3 cells with chicken embryo fibroblasts as host cells for 24 previously described substitution and deletion mutants with lesions in the SH2- and SH3-encoding regions of a transformation-competent allele of chicken c-src. Although several of these mutants are equally competent or equally defective for transformation of the two cell types, four mutants (three of which map within SH3) preferentially transform NIH 3T3 cells, and seven mutants (all of which map within SH2) preferentially transform chicken cells. Some of the SH2 mutants least able to transform mouse cells exhibit augmented transforming activity in chicken cells. In general, the in vitro protein-tyrosine kinase activities of the mutants correlated with transforming activities. Thus, in many cases, the catalytic activity of a mutant protein depended upon the host cell in which the protein was made. Such host-dependent mutants may be especially useful reagents for biochemical and genetic studies of the src gene family.
Lack of effect of chronic administration of oral beta-carotene on serum cholesterol and triglyceride concentrations. Previous studies suggest that chronic oral administration of retinol and other retinoids causes elevation of plasma triglyceride concentrations. The effects of chronic oral administration of beta-carotene, a carotenoid partially metabolized to retinol, on plasma lipid concentrations have not been well studied; therefore, we studied 61 subjects over 12 mo while they were enrolled in a skin-cancer-prevention study in which patients were randomly assigned to receive either placebo (n = 30) or 50 mg beta-carotene/d orally (n = 31). At study entry and 1 y later, fasting blood samples were obtained for measurement of triglycerides, total cholesterol, HDL cholesterol, retinol, and beta-carotene. Retinol concentrations changed minimally in both groups; beta-carotene concentration increased an average of 12.1 +/- 47 nmol/L in the placebo group and 4279 +/- 657 nmol/L in the active-treatment group. Both groups experienced similar small increases in triglyceride and total cholesterol concentrations and small decreases in HDL cholesterol. Daily oral administration of 50 mg beta-carotene/d did not affect plasma lipid concentrations.
Brain water content, brain blood volume, blood chemistry, and pathology in a model of cerebral edema. STUDY OBJECTIVES: The objective was to correlate regional changes during brain water content with alterations in blood chemistry and cerebral pathology during hypo-osmotic edema. PARTICIPANTS: Sprague-Dawley male adult rats were used in these studies. DESIGN: Animals were block-randomized to receive either an intraperitoneal distilled water injection equivalent to 5% or 15% of their body weight or no injection (controls). Rats were sacrificed 15 or 60 minutes after water injection or at an equivalent time for controls. INTERVENTIONS: No interventions were performed. MEASUREMENTS AND MAIN RESULTS: Water content of cerebral cortical gray and white matter was calculated from measurements of tissue specific gravity. Blood plasma osmolality and sodium and potassium concentrations were determined at various times after water injection. An index of blood-brain barrier permeability was obtained by measuring brain red blood cell and plasma volumes. A qualitative assessment of edema was made from light and electron micrographs of the cerebral cortex. We found that water injection produced a dose-dependent decrease in plasma osmolality and sodium concentration within 15 minutes. Cortical water content was unchanged after this period. An influx of water into cerebral gray, and, less readily, into cerebral white matter occurred during the next 15 minutes. Whole blood specific gravity and brain blood content were unchanged and thus did not confound the measurement of cerebral water content. Hematocrit was increased 60 minutes after a 15% water injection. The blood-brain barrier remained intact throughout this period. Microscopy revealed astrocytic swelling with slight extracellular fluid accumulation 60 minutes after the water injection. CONCLUSIONS: Homeostatic mechanisms in the cerebral cortex can maintain constant water content for at least 15 minutes during maintained intravascular hypo-osmolality. Fluid that subsequently moves into the tissue primarily enters an intracellular compartment. This model will be useful in investigating physiological mechanisms of brain water regulation and the pathogenesis of brain edema, a common clinical entity in emergency conditions.
A prospective randomized study of cerebrospinal fluid drainage to prevent paraplegia after high-risk surgery on the thoracoabdominal aorta. This article is concerned with the study of the effect of several variables, principally that of cerebrospinal fluid drainage, on the incidence of neurologic deficit in a prospective randomized series of patients with extensive aneurysms of the descending thoracic and abdominal aorta (thoracoabdominal type I and II). Forty-six patients had cerebrospinal fluid drainage, and 52 were controls, with a total of 98 available for study. Cerebrospinal fluid pressure was continuously monitored in the former group and pressure maintained less than or equal to 10 mm Hg in 20, less than or equal to 15 mm Hg in 20, and greater than 15 mm Hg in 6 patients during period of aortic clamping. The method of treatment including reattachment of intercostal and lumbar arteries (p = 0.2), temporary atriofemoral bypass during aortic occlusion (p = 0.3), and spinal fluid drainage (p = 0.8) were not statistically significant in reducing the incidence of neurologic deficits. Thus cerebrospinal fluid drainage as we used it, was not beneficial in preventing paraplegia. On appropriate statistical analysis we found that the only significant predictor of delayed deficits was postoperative hypotension (p = 0.006).
Splenectomy for the massively enlarged spleen. The experience at the National Cancer Institute from 1955 to 1988 with 46 cases of splenectomy for massive splenomegaly (greater than or equal to 1,500 grams) was reviewed to assess the indications, pathology, operative, and postoperative course for this procedure. The median age was 51 years. Thirty-one splenectomies (67.4%) were performed for malignancy (chronic lymphocytic leukemia, 11; chronic myelogenous leukemia, 10; lymphoma, 9; hairy cell leukemia, 1), 11 for myeloid metaplasia, and four for other nonmalignant conditions. Indications for splenectomy included hypersplenism (32 patients), symptoms (6), diagnosis (3), and splenic rupture (3). A midline incision (30 patients) was most commonly used. Median operative time was 2 hours, 50 minutes. Median operative blood loss was 1,300 ml (range, 100 ml-60 units). The splenic artery was ligated initially in 16 patients (34.8%) but did not correlate with blood loss or operating time. The median splenic weight was 2,030 grams (range, 1500-5320 gm). The postoperative complication rate was 39.1 per cent (21 complications in 18 patients). This included infection in 10 patients, bleeding in six patients. Six patients required reoperation (bleeding, 4; abscess, 1; small bowel obstruction, 1 patient). The 30-day operative mortality was 19.6 per cent (9 patients). Excluding operative deaths, 35 patients were available for follow-up evaluation. Twenty-nine patients had improvement in parameters for which splenectomy was indicated. Six patients had no change in their course after splenectomy. These findings indicate that many patients with massive splenomegaly benefit from splenectomy, however, the procedure is associated with a high risk for postoperative morbidity and mortality.
Pelvic floor descent in women: dynamic evaluation with fast MR imaging and cinematic display. The authors present a new method for assessing pelvic prolapse with dynamic fast magnetic resonance (MR) imaging. Twenty-six women with signs and symptoms suggesting pelvic prolapse and 16 control subjects were studied with a series of fast (6-12-second) MR images. Sagittal and coronal images were obtained with graded increase in voluntary pelvic strain, allowing for dynamic display and quantification of the pelvic prolapse process. The distance from the pubococcygeal line was used as an internal reference for measurement of descent in the maximal strain position. With use of control results for normal limit values, prolapse involving the anterior pelvic compartment (cystocele), the middle compartment (vaginal prolapse, uterine prolapse, and enterocele), and the posterior compartment (rectocele) was easily demonstrated. Significant differences between control subjects and patients with prolapse were seen at maximal strain but not in the relaxed state. Quantification of the pelvic descent process with use of fast MR imaging may be of value in surgical planning and postsurgical follow-up.
Operative choledochoscopy: common bile duct exploration is incomplete without it. This paper reviews the reported experience of operative choledochoscopy. Development of choledochoscopes to the currently available rigid and flexible instruments is described. The collected results of both rigid and flexible choledochoscopy are reported. Retained stones occurred in 97 of 2712 stone-positive explorations with the rigid choledochoscope (3.6 per cent) and in 35 of 1726 stone-positive explorations with the flexible choledochoscope (2.0 per cent). Choledochoscopy should now be a mandatory part of common bile duct exploration.
Emergency intraosseous infusion in severely burned children. Severely burned patients require rapid administration of large volumes of isotonic fluids. Obtaining adequate intravenous (IV) access in children with greater than 70% total body surface area burns may be difficult, time-consuming, and sometimes impossible. This report describes the use of intraosseous infusion technique as a life-saving means of establishing IV access in two severely burned children.
The disabled driver: an unmet challenge. A survey was undertaken to determine if driving impairment secondary to a disabling injury is addressed in state licensing laws and training programs. In 35 states drivers submit voluntarily to reevaluation after disabling injuries, but no provision is made for reporting such individuals. Only 15 states authorize physicians to report impaired drivers, and only seven require such reporting. Based on a survey of licensing bureaus in the capital or a major city of every state, clerks (who are likely to be the source of information to injured persons) are generally not aware of reporting requirements and supervisors are only slightly better informed. Of the 100 rehabilitation centers surveyed, only 36 provided on-site training for disabled drivers. Voluntary submission for reevaluation after head injury does not often occur. Despite being asked to do so, none of the 35 head injured patients, followed up to two years post-onset, sought reevaluation, although 21 had resumed regular driving. Two of the 21 were involved in subsequent traffic accidents. Common guidelines need to be established across states to ensure reevaluation of individuals with disabling conditions, delivery of accurate information concerning licensing, and availability of training programs.
Menopausal estrogen replacement therapy and breast cancer We conducted a meta-analysis of the literature concerning breast cancer and estrogen replacement therapy. The overall relative risk of breast cancer associated with this therapy was 1.07. However, the variation of the estimated risks among the studies was far greater than could plausibly be explained by chance alone. To explain this variation, we looked at the effects of type, duration, and dosage of treatment. Overall, women who took 0.625 mg/d or less of conjugated estrogens had a risk of breast cancer that was 1.08 times that of women who did not receive this therapy (95% confidence interval [CI], 0.96 to 1.2). The relative risks from these individual studies of low-dosage therapy did not differ significantly from each other. Women who took 1.25 mg/d or more of conjugated estrogens had a breast cancer relative risk of 2.0 or less in all studies. However, the variation in observed risks at this higher dosage was significant. This implies that other risk factors varied among these studies, making it difficult to estimate the overall risk associated with this dosage. The relative risk of breast cancer associated with estrogen replacement therapy among women with a history of benign breast disease was 1.16 (95% CI, 0.89 to 1.5). The combined results from multiple studies provide strong evidence that menopausal therapy consisting of 0.625 mg/d or less of conjugated estrogens does not increase breast cancer risk.
Stiffman syndrome: a rare paraneoplastic disorder? An unusual case of the stiffman syndrome, associated with an oat cell carcinoma of the bronchus, is reported. Pathological examination showed that it was due to an encephalomyelitis similar to that seen in paraneoplastic disorders. This suggests that atypical cases of the stiffman syndrome may occasionally be paraneoplastic.
In vivo phosphorus 31 magnetic resonance spectroscopy of human uveal melanomas and other intraocular tumors. We studied the feasibility of using the surface coil probe technique for the noninvasive in vivo study of ocular tumors by phosphorus 31 magnetic resonance spectroscopy. The characteristic organophosphate metabolites of suspected uveal melanomas before proton beam irradiation were determined qualitatively by phosphorus 31 magnetic resonance spectroscopy in vivo using a three-turn surface coil. Spectra of choroidal hemangioma, osteoma, and metastasis were also obtained in vivo and compared with those of uveal melanomas. Analysis of spectra performed at 1.5 T showed significant peaks of phosphomonoesters, inorganic phosphate, phosphodiesters, phosphocreatine, and adenosine 5'-triphosphates. The unusually high concentration of phosphodiesters may be considered as a marker for uveal melanomas and other choroidal tumors. By analyzing the ratio of phosphocreatine to phosphodiesters spectral area values, we interpreted qualitatively spectra of intraocular tumors to differentiate malignant tumors from benign lesions. Nevertheless, the main limitation of interpreting the spectra was their contamination by signals from surrounding tissues.
Ventricular tachycardia and accelerated ventricular rhythm presenting in the first month of life. Fourteen infants aged less than 1 month presented to our institution during the last 22 years with ventricular tachycardia (VT) or accelerated ventricular rhythm and a structurally normal heart. In 2, VT was associated with long QT syndrome. Both are alive on beta-blocker therapy, 1 with an implanted pacemaker. Twelve infants had accelerated ventricular rhythm, and 2 of these died in the first 2 months of life of unrelated conditions. The other 10 are alive at a median age of 4 years (range 2 months to 11 years), and none were lost to follow-up. Hemodynamic compromise did not occur with accelerated ventricular rhythm. The ventricular rate was very close to the sinus rate in all 12, less than 12% above the sinus rate. The mean QRS duration during accelerated ventricular rhythm was 92.5 ms, and averaged twice the QRS duration during sinus rhythm. Fusion beats were seen in all 12, and there was atrioventricular dissociation with capture beats in 10. In 2, ventriculoatrial conduction was present. Treatment was attempted in 5 of the 10 survivors with accelerated ventricular rhythm, and was thought to be successful in 4. Treatment was later successfully withdrawn in all 5, so that all 10 survivors were free of accelerated ventricular rhythm and were not receiving antiarrhythmic medications at last follow-up. Because of the excellent long-term outcome and the lack of hemodynamic compromise during the rhythm, it seems reasonable to withhold antiarrhythmic therapy in infants with accelerated ventricular rhythm and await resolution of the rhythm.
Endemic Kaposi's sarcoma in human immunodeficiency virus type 1-seronegative persons: demonstration of retrovirus-like particles in cutaneous lesions. In 1984, Greek physicians reported on the clustering of cases of Kaposi's sarcoma (KS) on the Peloponnesus peninsula. To gain more insight into its pathogenesis, we studied the seroepidemiologic and clinicopathologic characteristics of 12 Greek KS patients (eight male/four female) five of whom were residents of an endemic area on the Peloponnesus. These patients were in good general health with ages ranging from 48 to 80 years, had no clinical signs of immunodeficiency, and combined the features of both classic and epidemic KS in that they displayed not only involvement of acral areas but also widespread mucocutaneous lesions. Routine laboratory data were within normal limits; no patient had HTLV-1 and HIV-1/2 antibodies, but all patients had antibodies to several herpesviruses. The histopathology was characteristic of KS with the peculiar feature of a dense infiltrate composed predominantly of CD4+ T lymphocytes. Immunoenzymatic/morphologic studies of the KS cells were consistent with their origin from lymphatic endothelium. Outstanding ultrastructural findings were tubuloreticular structures and cylindrical confronting cisternae, structures that are indicative of an ongoing viral infection. Indeed, extensive electronmicroscopic studies resulted in the detection of retrovirus-like particles in close association to KS cells in five of 12 patients. This in situ observation opens the possibility that this retro-virus contributes to KS development.
A rare cause of colitis--Brucella melitensis. Report of a case. Documentation of gastrointestinal lesions in Brucella infections is sparse. A case of Brucella melitensis type 3 infection accompanied by erosive lesions of the colon, observed by endoscopy and histopathologic examination, is reported. Such gastrointestinal lesions have not been described since 1934. Before 1934 only postmortem observations are recorded.
Photodynamic therapy with chloroaluminum-sulfonated phthalocyanine. To study the vascular effects of a new photosensitizing agent independent of the influence of tumor growth, a cutaneous wound model was used. Six-week-old Harlan-Sprague-Dawley "Fuzzy" rats were surgically wounded in a standard fashion. The animals were then divided into three groups: the first group received chloroaluminum-sulfonated phthalocyanine only, the second group was treated with light only, and a third group was treated with both chloroaluminum-sulfonated phthalocyanine and light. Photodynamic therapy with chloroaluminum-sulfonated phthalocyanine had a direct effect on the neovasculature of a healing wound. The vasodilatation that was seen in the wound neovasculature that occurred 12 hours after the completion of chloroaluminum-sulfonated phthalocyanine-photodynamic therapy may have indicated a therapeutic "window" at which other therapies can be employed to improve clinical efficacy.
Crohn's disease of the lung Two years after developing colonic Crohn's disease, a 17 year old boy presented with focal pulmonary consolidation. A lung biopsy specimen showed areas of non-caseating epithelioid granuloma. Although some respiratory abnormalities appear to be associated with inflammatory bowel disease, granulomatous disease affecting the lung has not previously been reported in a child.
Endoscopic sclerotherapy for control of bleeding varices in children. Thirty-three children with esophageal varices due to portal hypertension underwent injection sclerotherapy over a period of 6 yr. Thirty-one completed the sclerotherapy course, and the varices were eradicated in all. In nine, the procedure was performed as an emergency because of continued bleeding and, in each case, a gastric fundal varix was the source of the blood loss. Sclerotherapy successfully controlled the bleeding in four of these, whereas five required surgical underrunning of the fundal varix. After surgery, these five continued sclerotherapy until the esophageal varices were eradicated. Complications included transient pyrexia (39%), retrosternal discomfort (30%), esophageal ulceration (18%), and esophageal stricture (12%). Rebleeding before initial eradication of the varices occurred in 12 patients but, thereafter, was very uncommon and always small in amount. Esophageal varices recurred after initial eradication in 33% of cases but were easily sclerosed with further injections. This study demonstrates that sclerotherapy is effective in reducing bleeding frequency in children with portal hypertension, but emphasizes the need for regular follow-up endoscopy after initial eradication of esophageal varices.
Prognostic determinants in extracorporeal membrane oxygenation for respiratory failure in newborns. Extracorporeal membrane oxygenation (ECMO) is becoming an accepted therapeutic modality for newborn respiratory failure, but there is little information available regarding the prognostic determinants with this technique. One hundred thirty-five newborns treated with ECMO over a 4-year period were critically analyzed with regard to the influence that birth weight, gestational age, age at initiation of ECMO, best blood gases before ECMO, number of hours on ECMO, renal failure, intracerebral hemorrhage, and long-distance air transport had on survival. Infants with meconium aspiration and those undergoing long-distance transfer showed significant differences in blood gases before ECMO, with survivors having more normal pH and carbon dioxide tension values. Intracerebral hemorrhage and renal failure that developed during ECMO were grave prognostic signs, with few survivors in either group. These data show that ability to ventilate patients before ECMO, giving normal carbon dioxide tension and pH values, is an important prognostic sign in infants with meconium aspiration and undergoing long-distance transfer for ECMO, whereas renal failure and intracerebral hemorrhage are usually lethal complications of ECMO. Each center performing ECMO should continually reevaluate this invasive technique and its results and complications.