123rc/medical_text huggingface dataset:
Dietary deficiency of antioxidants exacerbates ischemic injury in the rat kidney. We examined the effects of dietary deficiency of vitamin E and selenium on the ischemia-reperfusion model of renal injury in the rat. Deficient diets imposed for six weeks on three-week-old weanling rats led to no significant differences in body weights, serum creatinine, GFR, RBF, TmPAH or urinary total protein excretory rates prior to ischemia. Twenty-four hours after one hour of ischemia, animals on the deficient diet demonstrated more markedly impaired GFR, RBF, TmPAH and urine to plasma creatinine concentrations and an increased renal failure index. Tubular damage was more severe injury in the deficient animals. Lipid peroxidation, 15 minutes after the release of the ischemic clamp, was increased in the deficient animals. We confirmed the effects of our dietary manipulation in impairing the oxidant scavenging system in the deficient animals since glutathione peroxidase activity was reduced to less than 5% in the basal state, and this striking reduction persisted following ischemia. Plasma vitamin E concentrations were also markedly depressed in the deficient diets. This dietary deficiency also worsened the course of acute renal injury and was accompanied by 50% mortality compared to 0% mortality in the control animals. Thus, dietary deficiency of vitamin E and selenium led to greater structural and functional renal impairment and increased lipid peroxidation following ischemia. These data provide support for the role of reactive oxygen species in mediating ischemia-reperfusion injury.
Fucosylated oligosaccharides of human milk protect suckling mice from heat-stabile enterotoxin of Escherichia coli. Human milk protects suckling mice from the diarrheagenic effects of heat-stabile enterotoxin of Escherichia coli (ST). To identify the human milk fraction responsible for this protection, pooled skimmed, deproteinated milk was passed through charcoal, whereupon lactose was separated from the oligosaccharides. The oligosaccharides contained ST-protective activity; the lactose did not. The neutral, but not the acidic, fraction exhibited protective activity against ST (22% vs. 57% mortality, respectively; P less than .001). The fucosylated, but not the nonfucosylated, subfractions of the neutral fraction contained the factor protective against ST (35% vs. 50% mortality, respectively; P less than .05). An oligosaccharide isolation scheme based on different principles produced confirmatory results. The commercially available neutral fucosylated oligosaccharides of human milk did not significantly protect the mice from the effects of ST. Thus, the protective factor against ST seems to be a minor neutral fucosyloligosaccharide of human milk.
Laryngeal framework reconstruction with miniplates. Defects of the laryngeal framework after trauma, cancer, and thyroplasty have been reconstructed with mini-reconstruction plates. Six patients had miniplates used to repair the thyroid cartilage defect after type I thyroplasty to prevent lateralization of the Silastic implant; three patients had miniplates used after hemilaryngectomy to bridge the thyroid cartilage remnants, resulting in better deglutition after hemilaryngectomy; and three patients had miniplates used to repair laryngeal fractures. The plates were tolerated well by the patients; there were no major complications. Rigid fixation using miniplates for laryngeal reconstruction has unique advantages over the use of wires. It offers the advantages of rigid and immediate stabilization with the ability to bridge large defects. It can be an alternative to existing techniques of laryngeal reconstruction.
Tumor of the atrioventricular nodal region. A clinical and immunohistochemical study. Autopsy specimens of 17 tumors of the atrioventricular nodal region were studied. Sudden death occurred in 14 children and adults; seven of these patients had a history of atrioventricular block or syncope. Three tumors were incidental findings in infants with other congenital anomalies; diaphragmatic agenesis, pulmonary hypoplasia, and Meckel's diverticulum in one patient; mitral atresia in one; and congenital hydrocephalus, ventricular septal defect, patent ductus arteriosus, coarctation of the aorta, and patent omphalovitelline duct in the third. Immunohistochemical stains demonstrated strong positivity for carcinoembryonic antigen in 13 of 13 cases, B72.3 antigen in 5 of 7 cases, and cytokeratin in 11 of 11 cases. Twenty control cases of mesothelioma and mesothelial hyperplasia were all negative for B72.3; one showed focal carcinoembryonic antigen staining. Ultrastructural analysis of one case demonstrated short rudimentary microvilli not characteristic of mesothelial cells. We conclude that so-called mesotheliomas of the atrioventricular nodal region are not of mesothelial origin, because of strong carcinoembryonic antigen positivity and occasional positivity with B72.3, as these antibodies react with glycoproteins found in endodermally derived tissue and generally not with mesothelial tissue. Conduction system tumors are most likely congenital rests of endodermal origin, can be associated with other congenital anomalies, and often cause symptoms of heart block and sudden death.
Receptor imaging: application to MR imaging of liver cancer. A new contrast agent for magnetic resonance (MR) imaging, directed to asialoglycoprotein (ASG) receptors on hepatocytes, was used for detection of liver cancer in rats. Ultrasmall superparamagnetic (mean size, 12 nm) particles of iron oxide (USPIOs) were targeted to ASG receptors by coating particles with arabinogalactan (AG). Liver T2 relaxation times decreased more effectively after a single intravenous administration of AG-USPIO than after an equal dose of a conventional superparamagnetic liver MR contrast agent (AMI-25; mean size, 72 nm). Receptor affinity studies demonstrated that receptor-mediated attachment and subsequent cellular endocytosis do not occur in primary malignant (hepatocellular carcinoma) or metastatic (adenocarcinoma) tumors, because the surface ASG receptors are lost during malignant dedifferentiation. In vitro relaxation and in vivo MR imaging experiments of liver tumors show that targeting USPIO to hepatocytes rather than to the mononuclear phagocytic system allows a considerable dose reduction, increases tumor-liver contrast, and potentially allows distinction of ASG-positive (benign hepatocellular) and ASG-negative (malignant hepatocellular) tumors.
Persistent lower respiratory tract inflammation associated with interstitial lung disease in patients with tropical pulmonary eosinophilia following conventional treatment with diethylcarbamazine. Tropical pulmonary eosinophilia (TPE) presents as an acute syndrome with dyspnea, fluffy infiltrates, and rounded opacities on the chest radiograph, reduced lung function, marked eosinophilia in the blood and lower respiratory tract, and high titers of specific IgE and IgG antifilarial antibodies. The standard therapy for TPE is a 3-wk course of diethylcarbamazine (DEC) following which there is almost always a marked improvement in all parameters. However, clinical observations suggest that the disease can persist despite DEC therapy and lead to chronic dyspnea with restrictive lung impairment. To evaluate the concept that DEC therapy is not completely "curative" for TPE, but rather leaves most individuals with a mild, chronic form of TPE defined by persistent inflammation of the lower respiratory tract, we evaluated 23 individuals an average of 12 +/- 2 months following a standard 3-wk course of diethylcarbamazine for acute TPE. In the majority there were mild, persistent symptoms referrable to the lung, chest X-ray abnormalities, blood eosinophilia, and elevated serum IgE and filarial specific IgG. On the average, lung function was consistent with the presence of chronic, mild interstitial lung disease. When the inflammatory cells from the lower respiratory tract were examined, there was a persistent eosinophilic alveolitis (TPE/post-DEC 1769 +/- 376 eosinophils/microliters epithelial lining fluid; normal subjects 256 +/- 38, p less than 0.02). Evaluation of the lower respiratory tract inflammatory cells recovered from the TPE/post-DEC-treated individuals demonstrated spontaneous release of exaggerated amounts of O2-. and H2O2 compared to normal subjects (p less than 0.05, both comparisons).
Mediastinitis following coronary artery bypass surgery: a 3-year review. Twenty cases of mediastinitis after coronary artery bypass graft operations in 1985-1987 were reviewed to determine risk factors. Two distinct clusters with a methicillin-resistant Staphylococcus aureus (MRSA) strain occurred in 1986. One resident was exposed to six cases but to only 5 of 24 controls (P less than .008). Cultures of his nares in January and November 1986 revealed the same MRSA strain as that of the cases. An attempt to eradicate the resident's nasal carriage of MRSA in January 1986 failed; eradication of his carrier state was achieved only after treatment with mupirocin. In a case-control study examining patients exposed to the resident, a prolonged duration of surgery (P less than .05) and a preoperative albumin level of less than 3.0 g/dl (P less than .009) were associated with mediastinitis with this MRSA. For the other 14 mediastinitis patients, who were not exposed to the resident, a preoperative albumin level of less than 3.0 g/dl was also a risk factor (8/14 cases vs. 8/43 controls, P less than .009). Thus, this study suggests that it is important to follow MRSA disseminators and to recognize that preoperative serum albumin levels are a risk factor for mediastinitis.
Granulocyte-macrophage colony-stimulating factor synergizes with interleukin-6 in supporting the proliferation of human myeloma cells. The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the growth of multiple myeloma (MM) was investigated in 21 patients with MM. In 17 patients with proliferating myeloma cells in vivo, recombinant GM-CSF significantly increased the endogenous-IL-6-mediated spontaneous myeloma cell proliferation occurring in 5-day cultures of tumor cells in vitro (P less than .01). Furthermore, GM-CSF was detected in 5-day culture supernatants of myeloma bone marrow cells. This endogenous GM-CSF was produced by the myeloma bone marrow microenvironment but not by myeloma cells and contributed to the spontaneous myeloma-cell proliferation observed in 5-day cultures. In fact, this proliferation was partially blocked (67%) by anti-GM-CSF monoclonal antibodies. The stimulatory effect of rGM-CSF was mediated through IL-6 because it was abrogated by anti-IL-6 monoclonal antibodies. rGM-CSF did not reproducibly increase the endogenous IL-6 production in short-term cultures of bone marrow cells of MM patients. Using an IL-6-dependent myeloma cell line (XG-1 cell line), rGM-CSF was shown to act directly on myeloma cells stimulating by twofold their IL-6 responsiveness. rGM-CSF did not induce any IL-6 production in XG-1 cells, nor was it able to sustain their growth alone. Although no detectable GM-CSF levels were found in the peripheral or bone marrow blood of MM patients, it is possible that GM-CSF, produced locally by the tumoral environment, enhances the IL-6 responsiveness of myeloma cells in vivo in a way similar to that reported here in vitro.
Angiographic assessment of the culprit coronary artery lesion before acute myocardial infarction. Serial angiographic studies of patients with myocardial infarction and unstable angina suggest that the culprit plaque underlying a thrombus need not have produced severe luminal obstruction before onset of the event. An atherosclerotic coronary artery lesion can, therefore, have 2 important characteristics. First, it may be obstructive. Second, it may be "vulnerable" in that it has the potential to become thrombogenic if exposed to the appropriate triggering stimulus. A lesion need not be obstructive to become thrombogenic, nor do all obstructive lesions have thrombogenic potential. The cause of an infarction may thus be rupture of a nonobstructive plaque leading to occlusive thrombus formation. Because it may be difficult to predict the site of a subsequent occlusion from a coronary angiogram, coronary bypass surgery or angioplasty directed only at discernible stenotic lesions may not be effective for preventing subsequent myocardial infarctions. Appropriate therapy may need to be directed at the entire coronary tree. Such therapy might include cholesterol lowering, beta blockade and aspirin.
Tourette syndrome and other tic disorders. Diagnosis, pathophysiology, and treatment. In this report, we discuss the definition, characteristics, pathophysiology, and treatment of tic disorders with a major emphasis on Tourette syndrome. Although the diagnosis of a tic disorder depends on the presence of motor and/or phonic tic(s), patients with these problems also have a variety of co-morbid features including obsessive-compulsive symptoms, attention-deficit hyperactivity disorder, behavioral difficulties, and learning disabilities. Conservative estimates for Tourette syndrome suggest a prevalence rate of 0.1-1.0 per 1000. This syndrome is inherited in a sex-influenced autosomal dominant pattern with either chronic multiple tic disorder or obsessive-compulsive disorder as alternative phenotypes of the putative gene. Current evidence continues to support a pathophysiologic mechanism involving synaptic neurotransmission, with the dopaminergic system as a primary candidate. Therapeutically, it is essential to clarify whether a patient's problems are related to tics or associated behavioral difficulties. Pharmacotherapy for motor and phonic tics is strictly symptomatic and should be reserved for those with functionally disabling symptoms. A comprehensive individualized treatment program is often required in the care of individuals with tic disorders.
Molecular phenotype of a pediatric small round cell tumor. Molecular probes were used to characterize an unusual small round cell abdominal tumor arising from the fallopian tube of a 15-year-old girl. DNA and RNA extracted from the tumor and adjacent normal tissue was subjected to Southern and Northern blot analysis using a variety of different probes. N-myc oncogene RNA was greatly expressed in the tumor, but was not expressed in normal tissue or amplified in chromosomal DNA. Insulin-like growth factor II RNA was similarly overexpressed in the neoplasm, but not in normal tissue. While histopathologic studies could not distinguish between a neuroectodermal neoplasm and Wilms' tumor, electron microscopy and the pattern of gene expression was most consistent with Wilms' tumor.
Point mutation, allelic loss and increased methylation of c-Ha-ras gene in human hepatocellular carcinoma. Somatic alterations of the c-Ha-ras gene were examined in 21 Japanese patients with hepatocellular carcinoma. Restriction endonuclease analysis by double digestion with MspI and HpaII revealed that DNAs from two of 21 hepatocellular carcinoma tissues were affected by nucleotide substitution at the twelfth amino acid coding sequence of the c-Ha-ras gene. DNAs from cirrhotic noncancerous liver tissue, but not leukocytes, of one of these patients possessed the mutation, whereas DNAs from noncirrhotic liver tissue and leukocytes of the other patient did not. In one of the nine patients harboring heterozygosity for c-Ha-ras-related BamHI-fragments, the loss of one allele was demonstrated as a somatic change not only in DNA from the tumor tissue but also in DNA from the cirrhotic nontumorous tissue. In two of the 19 patients comparatively examined for digestion patterns of c-Ha-ras locus with HpaII and MspI, extensive methylation was observed as a somatic modification in both DNAs from the tumor and the cirrhotic nontumorous tissues. These results thus indicate that the genetic lesions affecting the c-Ha-ras gene do occur in human hepatocellular carcinoma and probably serve as one of the multiple steps in the process of hepatic carcinogenesis.
Total pelvic exenteration with simultaneous bowel and urinary reconstruction. The technique of total pelvic exenteration with simultaneous bowel and urinary reconstruction is described as a surgical option for the management of pelvic sarcoma in adults and for highly selected patients with other types of advanced pelvic malignancy. The surgical technique is presented in detail as performed in a 43-year-old man who presented with extensive primitive pelvic sarcoma. We believe that this approach may provide the benefits of an exenterative operation without the undesirable psychosocial sequelae of a permanent colostomy and external urinary diversion.
Cardiac involvement in AIDS. Cardiac involvement in AIDS may occur at any stage of HIV disease and may manifest as congestive cardiomyopathy, potentially lethal arrhythmia, or pericardial effusion and tamponade. The heart may be affected by nearly all of the opportunistic infections and many of the malignancies associated with the syndrome. Although often clinically unobtrusive, cardiac lesions may be important in the pathogenesis of significant clinical symptoms and play an often unrecognized role in the prognosis and natural history of AIDS.
Diabetes insipidus associated with craniopharyngioma in pregnancy. A case is presented of a pregnancy complicated by a suprasellar mass diagnosed at 27 weeks' gestation. This patient developed diabetes insipidus, which was successfully treated with 1-desamino-8-D-arginine vasopressin. Thyrotropin-releasing hormone and ACTH stimulation tests were also abnormal, requiring the institution of thyroid and cortisol replacement therapy. The patient was delivered at 34 weeks' gestation secondary to worsening visual field testing. A craniotomy was performed in the postpartum period with removal of a craniopharyngioma. With successful medical treatment and careful observation, surgical intervention may be postponed until postpartum or until a gestational age with lower neonatal morbidity and mortality is reached.
Risks factors for cerebral infarction in good-grade patients after aneurysmal subarachnoid hemorrhage and surgery: a prospective study. A prospective series of 265 patients with aneurysmal subarachnoid hemorrhage (SAH) of Grades I to III (Hunt and Hess classification) upon admission were evaluated as to neurological outcome and computerized tomography (CT) findings 1 to 3 years (mean 1.4 years) after the SAH and surgery. A total of 73 patients underwent acute surgery (within 72 hours after the bleed: Days 0 to 3), 86 were operated on subacutely (between Days 4 and 7), and 91 had late surgery (on Day 8 or later). Fifteen patients died before surgery was undertaken and another 20 patients died during the follow-up period. A total of 104 patients received nimodipine and the rest of the patients received either placebo (109 patients) or no medication (52 patients). A logistical regression analysis revealed the following prognostic factors for cerebral infarction, in order of importance: the amount of blood on the primary CT scan; postoperative angiographic vasospasm; the timing of the operation; and a history of hypertension. The use of nimodipine was associated with a significant reduction of cerebral infarcts visualized by CT scanning in patients who received intermediate or late surgery. In patients who underwent acute surgery no significant difference between the incidence of cerebral infarcts was observed.
Pruritic papular eruption of the acquired immunodeficiency syndrome: a clinicopathologic study. The pruritic papular eruption of the acquired immunodeficiency syndrome is characterized by generalized, pruritic, skin-colored papules and nodules. Chronic lesions are excoriated and hyperpigmented. The eruption and pruritus typically wax and wane and are resistant to oral antihistamine and topical steroid therapy. The characteristic histologic features are (1) superficial and mid dermal perivascular and perifollicular mononuclear cell infiltrate with numerous eosinophils and (2) follicular damage of varying degrees. When compared with control subjects, these patients did not demonstrate any significant difference in laboratory or demographic data.
Mycosis fungoides-like lesions associated with phenytoin and carbamazepine therapy. We report the cases of four patients who were taking the anticonvulsant drugs phenytoin or carbamazepine and in whom skin lesions developed that showed histologic features suggestive of mycosis fungoides. Two patients had a solitary lesion on the trunk, whereas the other two patients had multiple plaques. In all four patients systemic signs were absent.
Ehlers-Danlos syndrome type IV: diagnosis and therapy of associated bowel perforation. Ehlers-Danlos syndrome type IV is a heritable disease of type III collagen metabolism. This diagnosis is suspected in a patient with a combination of clinical manifestations and family history, but it is confirmed only by culture of the patient's skin fibroblasts and demonstration of a defect in type III collagen metabolism. The disease may rarely present with spontaneous colonic perforation, a complication traditionally treated by primary closure of the perforated segment and creation of an end colostomy. Attempts at bowel reanastomosis have often resulted in repeated colon perforations. We present the first patient with Ehlers-Danlos type IV syndrome to develop a colon perforation proximal to an end colostomy, and discuss the surgical strategy to prevent recurrences of this and other postoperative complications associated with the syndrome.
Circadian rhythm of heart rate variability after acute myocardial infarction and its influence on the prognostic value of heart rate variability. This study examined heart rate (HR) variability in patients surviving acute myocardial infarction (AMI) to find the optimum time and duration of recording of the ambulatory electrocardiogram for the prediction of the risk of sudden cardiac death, or serious arrhythmic events, or both. Twenty patients (group I) who initially survived an AMI but later experienced serious events (death or symptomatic sustained ventricular tachycardia) during a 6-month follow-up were compared with 20 patients (group II) who remained free of complications for greater than 6 months after discharge. Groups I and II were matched with regard to age, gender, infarct site, ejection fraction, and beta-blocker treatment. HR variability was assessed in the 24-hour electrocardiograms recorded during the first 2 weeks after an AMI and in various portions of the complete 24-hour recording, with both the beginning and the length of the analyzed portion varied by 20 minutes (a total of 5,113 possibilities). The maximum reduction of HR variability in group I patients was systematically found when assessing HR variability in recordings starting approximately at 6 A.M. and lasting for approximately 8 hours. In the low-risk patient, the diurnal rhythm of HR variability is more marked than in the high-risk patient and the long-term components of HR variability due to the diurnal variation must be included in the measurement of HR variability when using it as a long-term predictor of risk from arrhythmic events after an AMI.