Hypersensitivity reactions to rifampin. Pathogenetic mechanisms, clinical manifestations, management strategies, and review of the anaphylactic-like reactions.

Many of the adverse events induced by rifampin have been considered allergic in origin. The flu-like syndrome and other hypersensitivity reactions seem to be caused by immune complexes, although their pathogenetic mechanisms are not fully elucidated. Many cases have been reported of the flu-like syndrome, thrombocytopenia, hemolytic anemia, and renal failure caused by rifampin.

Melatonin reduces lipid peroxidation and tissue edema in cerulein-induced acute pancreatitis in rats.

Since oxygen free radicals and lipid peroxidation have been implicated in the pathogenesis of an early stage of acute pancreatitis, we examined whether melatonin, a recently discovered free-radical scavenger, could attenuate pancreatic injury in Sprague-Dawley rats with cerulein-induced pancreatitis. Acute pancreatitis was induced by four intraperitoneal injections of cerulein (50 microg/kg body wt) given at 1-hr intervals. Thirty minutes after the last cerulein injection, the rats were killed and the degree of pancreatic edema, the level of lipid peroxidation in the pancreas, and serum amylase activity were increased significantly.

Identification of highly elevated levels of melatonin in bone marrow: its origin and significance.

Bone marrow is an important tissue in generation of immunocompetent and peripheral blood cells. The progenitors of hematopoietic cells in bone marrow exhibit continuous proliferation and differentiation and they are highly vulnerable to acute or chronic oxidative stress. In this investigation, highly elevated levels of the antioxidant melatonin were identified in rat bone marrow using immunocytochemistry, radioimmunoassay, high performance liquid chromatography with electrochemical detection and mass spectrometry.

Muscle infections caused by Salmonella species: case report and review.

We describe a patient with salmonella pyomyositis and review 30 other cases reported during the past 4 decades. Men outnumbered women by 2.9 to 1, and the median age of the patients was 51 years.

beta-Hemolytic streptococci and other beta-hemolytic organisms in apical periodontitis and severe marginal periodontitis.

Thirteen teeth with necrotic pulps and apical periodontitis and nine severe periodontal pockets were cultured for presence of beta-hemolytic streptococci and other beta-hemolytic organisms. Samples were dispersed and plated on two non-selective and one selective growth media and incubated anaerobically and in 10% CO2 in air. A total of 59 beta-hemolytic colonies were purified and identified.

Evolution of serum beta2-microglobulin concentrations during treatment of tuberculosis patients.

A total of 36 human immunodeficiency virus-seronegative patients were studied in order to evaluate serum beta2-M levels in immunocompetent patients with tuberculosis who were receiving treatment. Six measurements of several clinical and laboratory parameters were carried out at different intervals during the 6 months of treatment. The mean serum beta2-M at presentation was 149 nmol/l and 4 patients had values above the upper normal limit.

Melatonin regulates glucocorticoid receptor: an answer to its antiapoptotic action in thymus.

We have previouslyreported that low doses of melatonin inhibit apoptosis in both dexamethasone-treated cultured thymocytes (standard model for the study of apoptosis) and the intact thymus. Here we elucidate the mechanism by which this agent protects thymocytes from cell death induced by glucocorticoids. Our results demonstrate an effect of melatonin on the mRNA for antioxidant enzymes in thymocytes, also showing an unexpected regulation by dexamethasone of these mRNA.

Effect of site and rate of contrast material injection on pulmonary vascular distention.

Rationale And Objectives: The authors performed this study to determine if there were differences in vascular caliber measured on angiograms obtained with the injection protocol used for spiral computed tomography (CT) versus that used for pulmonary angiography.

Materials And Methods: The authors studied seven juvenile anesthetized pigs by using a prospective repeated measures experimental design. All pigs received injections of nonionic contrast material via catheters in the brachial vein, superior vena cava, main pulmonary artery, and left pulmonary artery.

In vitro measurements of water content and T2 relaxation times in lung using a clinical MRI scanner.

The purpose of this study was to validate water content measurements and to determine the T2 distribution in lung on a 1.5 T clinical magnetic resonance imaging (MRI) scanner. A single-slice 16 echo pulse sequence with an echo spacing of 10 msec was employed to scan 19 healthy juvenile pig lungs.

Clinically suspected pulmonary embolism: utility of spiral CT.

Purpose: To prospectively determine the utility of contrast material-enhanced spiral computed tomography (CT) in the examination of patients clinically suspected of having pulmonary embolism (PE).

Materials And Methods: One hundred ten patients clinically suspected of having PE were examined with contrast-enhanced spinal CT and at least one other imaging modality: ventilation-perfusion scintigraphy, Doppler ultrasonography of deep leg veins, or pulmonary angiography. Chart review or telephone contact with the referring clinician was used to evaluate the contribution of spiral CT to the final clinical diagnosis.

The oxidant/antioxidant network: role of melatonin.

Melatonin is now known to be a multifaceted free radical scavenger and antioxidant. It detoxifies a variety of free radicals and reactive oxygen intermediates including the hydroxyl radical, peroxynitrite anion, singlet oxygen and nitric oxide. Additionally, it reportedly stimulates several antioxidative enzymes including glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and superoxide dismutase; conversely, it inhibits a prooxidative enzyme, nitric oxide synthase.

Ultrastructural confirmation of neuronal protection by melatonin against the neurotoxin 6-hydroxydopamine cell damage.

6-Hydroxydopamine (6-OHDA) is a neurotoxin used in the induction of experimental Parkinson's disease in both animals and cultured neuronal cells. Biochemical and molecular approaches showed previously that low doses of 6-OHDA induced apoptosis in PC12 cells, while high doses of this neurotoxin induced necrosis. Melatonin has been shown to protect against the neuronal programmed cell death induced by 6-OHDA, although it was not able to prevent the massive necrotic cellular death occurring after the addition of high doses of the neurotoxin.

Melatonin decreases mRNA for histone H4 in thymus of young rats.

The antiproliferative properties of melatonin have been previously demonstrated for several normal and tumoral tissues. In a recent report we have shown that melatonin is able to inhibit programmed cell death in thymus both, in vivo and in vitro. Given that other authors have related programmed cell death and cell proliferation and that no previous reports on melatonin and cell division exist on thymus, we decide to study the possible antiproliferative effect of melatonin in this organ measured as the levels of mRNA for the histone H4.

Sonographic features of ovarian remnants.

Ovarian remnants occur after a portion of ovarian tissue is left behind unintentionally after oophorectomy. The ovarian remnant may be functional and cystic, producing pelvic pain and, in some patients, extrinsic compression of the distal ureter. Ovarian remnants frequently are associated with adhesions from previous pelvic surgery for endometriosis or pelvic inflammatory disease.

Sequential evaluation of serum adenosine deaminase in patients treated for tuberculosis.

Study Objective: To delineate the course of serum adenosine deaminase (s-ADA) in patients with tuberculosis who are receiving effective therapy.

Setting: A medical ward and an outpatient clinic in a general hospital.

Patients: Twenty-five immunocompetent patients with pleural or pulmonary tuberculosis.

Inhibition of cell proliferation: a mechanism likely to mediate the prevention of neuronal cell death by melatonin.

In a previous work we demonstrated that melatonin is able to prevent apoptosis induced by low doses of 6-hydroxydopamine (6-OHDA) in undifferentiated and neuronal PC12 cells. We also reported how this neurohormone was able to prevent the decrease in the mRNA for antioxidant enzymes caused by 6-OHDA. Although the antioxidant capability of melatonin seems to be clearly implicated in its antiapoptotic activity, literature suggests that its antiproliferative property could also be involved in its prevention of apoptosis.