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Biomedical subjects

M Levy

Publications and source records attributed to M Levy.

At least 289 records · Page 16Linked to original sources
PubMed1992

[Quantitative thallium myocardial tomoscintigraphy. Value of intravenous infusion of dipyridamole after negative submaximal exercise test].

Patients with suspected coronary artery disease are sometimes unable to exercise adequately (85% of age calculated maximal heart rate) to validate their ergometric stress test. Some groups suggest performing dipyridamole scintigraphy from the outset but then the information provided by exercise stress testing is lost. The aim of this study was to compare scintigraphies performed after exercise alone and after exercise combined with dipyridamole using a method of quantification. Thirteen patients with ischaemic heart disease without necrosis (coronary lesions greater than 75% luminal narrowing in: 7 right coronary, 10 left anterior descending, 3 left circumflex arteries and 1 left main coronary artery with 50% luminal narrowing) underwent exercise stress testing followed by Thallium imaging. One week later, the same exercise stress test was performed followed by an intravenous injection of dipyridamole and Thallium scintigraphy. The circumference of the radioactivity was traced and the surface of each segment calculated in three different short axis views, subdivided into 4 segments (anterior, lateral, inferior and septal walls). Any segment vascularised by a stenosed coronary artery was considered to be underperfused (105 segments). The ratios of the surfaces of underperfused/normal segments were compared using the two study protocols. Segments of the same wall in the 3 short axis views were grouped in the same myocardial zone. Thirty five myocardial zones were thus obtained: 25 zones were more underperfused after combining exercise and dipyridamole than after simple exercise stress (p = 0.014). The average increase in underperfusion after the combined exercise-dipyridamole was 12.4% compared with 5.5% after exercise alone (p = 0.03). Secondary effects were minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1992

[Skin manifestations revealing monocytic leukemia. A case report].

A three-month-old developed a deep nodule over the elbow, then two weeks later additional nodules over the trunk with enlargement of the liver and spleen. Examination of the bone marrow established the diagnosis of monocytic leukemia. Acute monocytic leukemia is the most common leukemia in infants. Skin lesions, visible as red, brown or purple nodules ("blueberry muffin lesions") and confluent areas of purpura are common and may occur as the first manifestations of the disease. These skin lesions are not specific of leukemia and other diagnoses should be considered including histiocytosis, neuroblastoma, and skin erythropoiesis (in Torch syndrome, hemolytic disease of the newborn, hereditary spherocytosis, and twin-to-twin transfusion syndrome).

Diagnosis, Differential↗
PubMed1992

Prenatal diagnosis of severe dermatologic diseases.

It is obvious that the nature of prenatal diagnosis of severe or lethal skin conditions is rapidly evolving. New molecular, enzymatic, and ultrastructural markers will become available. The biochemical base of many of these disorders will become known and the accuracy and utility of in utero diagnosis will improve. We wish to make one point again. The field is rapidly outpacing the ability of review articles to keep current. We urge you to refer to a genetic center for information when you are dealing with a situation in which prenatal diagnosis may be an issue.

Amniocentesis↗
PubMed1991

Immunological quantitation of levels of tissue inhibitor of metalloproteinase-1 in human colon cancer.

Treatment of rodent cells with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate activates protein kinase C, leading to increased expression of several genes, including a gene originally designated TPA-S1 or phorbin (M. D. Johnson, G. M. Housey, P. T. Kirschmeier, and I. B. Weinstein, Mol. Cell Biol., 7: 2821-2829, 1987). Sequence analysis of this cloned gene indicated homology with human erythroid-potentiating activity and tissue inhibitor of metalloproteinase (TIMP-1). Elevated levels of phorbin mRNA have been observed in human colon tumors (J. G. Guillem, M. F. Levey, L. L. Hsieh, M. D. Johnson, P. LoGerfo, K. A. Forde, and I. B. Weinstein, Mol. Carcinogen., 3: 68-74, 1990) and this increase correlated with the extent of invasion. To further investigate this phenomenon at the protein level, monoclonal antibodies were developed against the recombinant form of TIMP-1. A competitive enzyme-linked immunosorbent assay was developed for quantitation of the TIMP-1 protein in tissue extracts. Elevated levels of TIMP-1 protein were found in 31 human colon tumors, compared to paired samples of adjacent normal mucosa. In a subset of samples, previously analyzed for phorbin mRNA levels (n = 25), there was a good correlation between the abundance of TIMP-1 protein and phorbin mRNA. Immunoaffinity column purification of tumor extracts followed by Western blot analysis was used to confirm the enzyme-linked immunosorbent assay data. These results provide evidence that phorbin and TIMP-1 represent the same gene. In addition, the immunoassays we have developed may be useful in further studies on the role of TIMP-1 in human colon cancer.

Aged↗
PubMed1991

Contact formation and transfer of mannose BSA gold from macrophages to cocultured fibroblasts.

When macrophages were cocultured with fibroblasts many of the cells formed firm contacts. In some of these contacts both cell types were closely apposed and in others they were more clearly separated with numerous pseudopodia extending from macrophages toward the fibroblasts. Many small vesicles similar in structure to caveoli were observed immediately beneath the plasma membrane of some fibroblasts in regions immediately adjacent to areas of contact with macrophages. The membrane integrity of both cell types was always maintained and no connecting cytoplasmic strands were observed between contacting cells. Junctions were freely permeable to ruthenium red and less permeable to the larger cationized ferritin. Gold conjugated to mannose BSA was taken up readily by macrophages but not by fibroblasts. When fibroblasts were cocultured with macrophages that had been labeled with endocytosed gold, increasing amounts were transferred to them. Gold was observed within gaps formed between cocultured cells and within recipient fibroblasts in vesicles anatomically similar to lysosomes. These points of contact thus appear to provide a series of specialized protected clefts into which directed exocytosis of ligands from donor cells can take place and from which endocytosis into recipient cells is facilitated.

Animals↗
PubMed1991

Colchicine intoxication: clinical pharmacology, risk factors, features, and management.

The use of colchicine for acute gouty arthritis dates to ancient times. In recent years, colchicine also has been used successfully for various other rheumatic and nonrheumatic conditions. Colchicine is a safe drug when used according to established therapeutic guidelines. However, toxicity can be considerable if ingested intentionally or if the recommended doses are exceeded. Colchicine intoxication is characterized by multi-organ involvement and by the poor prognosis associated with administration of large amounts of the drug. Therapy is basically supportive and symptomatic because of the rapid distribution and binding of colchicine to the affected tissues. Use of anticolchicine antibodies is a novel approach that has shown promise in experimental models. Important research questions pertain to the effect of liver and kidney disease on colchicine metabolism, use of colchicine levels in the diagnosis of intoxication and for prognostication, and application of immunotoxicotherapy for colchicine poisoning in humans.

Animals↗
PubMed1991

Colchicine prophylaxis in familial Mediterranean fever: reappraisal after 15 years.

As determined in this study of 45 patients, the prolonged use of colchicine therapy in familial Mediterranean fever (FMF) is safe and effective in preventing flares of FMF and amyloidosis. It has acceptable adverse effect profile and can be used in children and pregnant women. Its discontinuation predisposes patients to acute FMF attacks and the development of amyloidosis. Articular involvement is less responsive to colchicine and may require therapy with nonsteroidal antiinflammatory drugs.

Adolescent↗
PubMed1991

Absence of tolerance to the excitatory effects of benzodiazepines: clonazepam-evoked shaking behavior in the rat.

Select benzodiazepine (BDZ) agonists, such as clonazepam, evoke wet-dog shakes (WDS) in the rat, a behavior which may be influenced by serotonergic drugs. To further study the role of serotonin (5-HT) and BDZ receptors in BDZ-induced WDS, we injected adult rats daily for 21 days with clonazepam and measured WDS and 5-HT1, 5-HT2, and BDZ receptors. Clonazepam 5 mg/kg upregulated 5-HT1 and 5-HT2 receptors in frontal cortex, but not in brainstem or spinal cord, compared to vehicle controls, without a change in BDZ receptors. A 10 mg/kg dose of the same drugs, however, did not alter 5-HT receptors. Chronic treatment with clonazepam failed to decrease clonazepam-induced WDS, resulting instead in a significant increase. The increase was prevented by chronic cotreatment with the 5-HT2 antagonist ketanserin, which significantly down-regulated 5-HT2 and BDZ sites. In vitro, clonazepam did not inhibit radioligand binding at 5-HT1 or 5-HT2 receptors in frontal cortex, brainstem, or spinal cord. Lack of tolerance to WDS evoked by clonazepam suggests different mechanisms for the excitatory and inhibitory effects of BDZs. The dose-independent effects of chronic clonazepam administration on 5-HT receptors are not mediated by activity of clonazepam at 5-HT receptor recognition sites.

Animals↗
PubMed1991

Social support for exercise: relationship to physical activity in young adults.

BACKGROUND: Physical inactivity is an independent risk factor for cardiovascular disease, yet little is known concerning factors which influence participation in physical activity or exercise. Two studies assessed the relationships between self-reported physical activity and social support for exercise. METHOD: One study involved a biracial sample of middle-class male and female teachers (mean age = 38.5 +/- 8.9 years) and one involved a biracial sample of lower- to middle-class males and females (mean age = 35.8 +/- 5.1 years). RESULTS: In both studies the social support scales had high internal consistencies and a two-component solution identical to the original validation study. In both studies, social support for exercise positively correlated with physical activity, but the relationships were mediated by race, gender, specific types of support (i.e., family, friend), and dimensions of physical activity (i.e., global, work, sports, and leisure). In both studies, regardless of work status and race, women's overall activity, particularly during leisure time, was positively related to family support for exercise. In both studies white women's overall activity levels, especially sports and leisure activities, were positively related to friend support. In both studies, black women's sports activity was positively associated with family support. Among white men in both studies, sports activities and total energy expenditure were positively related to family and friend support. Black men's sports-related activity was positively related to family support among the teachers and to friend support among subjects in the second study. CONCLUSION: Findings are discussed in terms of future research directed toward identification of other familial and sociocultural variables which might influence individuals' involvement in physical activity.

Adult↗
PubMed1991

Intrathecal synthesis of IgG subclasses in multiple sclerosis and in acquired immunodeficiency syndrome (AIDS).

Serum and cerebrospinal fluid (CSF) of 50 neurological patients (24 multiple sclerosis (MS), ten acquired immunodeficiency syndrome (AIDS) and 16 other neurological diseases (OND)) and ten controls were analyzed by enzyme-linked immunosorbent assay (ELISA) for IgG subclass quantification and for the calculation of intrathecal synthesis (ITS). Total IgG was determined by two methods: electroimmunodiffusion (EID) and ELISA. A highly significant correlation was established between both methods. The existence of ITS was proved by the IgG/albumin ratio, the IgG index, Tourtellotte's formula, and Schuller's formula. In AIDS patients all IgG subclasses showed an increase in the CSF, whereas in sera only the IgG1 was significantly increased. CSF of MS patients showed a predominant increase of IgG1 whereas no significant modification of IgG subclasses was observed in sera. In most of the AIDS patients there was an ITS of IgG1, IgG3 and IgG4, but rarely (3/10) IgG2. In contrast, a polyclonal ITS of IgG was exceptional (1/24) in MS patients. No significant correlation could be established between clinical data and IgG subclass ITS in MS. The variations of each IgG subclass in serum and in ITS were not significantly correlated. Measurement of each IgG subclass and calculation of ITS seems essential in order to analyze any subclass antibody repertory inside the central nervous system.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Fetal outcome following intrauterine amantadine exposure.

Amantadine hydrochloride is a well-known antiviral agent that has been used for the prevention of influenza A2, the treatment of Parkinson disease, and, more recently, multiple sclerosis. However, very few data exist about its use in pregnant women. We report a 34-year-old woman who had used amantadine to prevent relapse of her multiple sclerosis throughout two of her pregnancies who subsequently delivered two normal infants. We review the available animal data and two other human pregnancy exposure reports.

Adult↗