PubMed Health⌕ Search

Biomedical subjects

A Levin

Publications and source records attributed to A Levin.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Prenatal diagnosis of albinism].

Prenatal diagnosis of oculocutaneous albinism (OCA) was made in 1 of 6 pregnancies at risk examined during the 20th week of gestation. A skin biopsy was taken from the fetal scalp under ultrasonic screening. Light and electron microscopy studies were performed in each case to demonstrate melanin pigment and melanosomal development in the melanocytes of the hair bulbs and the epidermis. In 1 fetus albinism was diagnosed by the absence of melanin pigment and by the demonstration that melanosomes were only present in stages I and II. In the other 5 fetuses melanin pigment and mature melanosomes (up to stage IV) were demonstrated. The pregnancy with the albino fetus was interrupted and the diagnosis of OCA was confirmed at autopsy.

Albinism, Oculocutaneous↗
PubMed1991

Prevention of hemodialysis subclavian vein catheter infections by topical povidone-iodine.

Subclavian catheter (SCC) related infections are a major cause of morbidity in hemodialysis patients, the vast majority due to staphylococci species. Povidone-iodine (PI) has proven anti-staphylococcal activity. Therefore, a randomized controlled trial of topical PI ointment was undertaken to evaluate the impact of this prophylactic intervention on the incidence of SCC related infections in hemodialysis patients. The role of S. aureus nasal carrier state in the acquisition of infection was also evaluated. Patients requiring SCC for temporary hemodialysis access were randomized to receive the treatment (T; N = 63) or sterile gauze dressings alone (C; N = 66). Catheter duration ranged from 2 to 210 days in both groups, with a mean of 38.6 days in T and 36.2 days in C (NS). Exit site (ES) infections were significantly less in T (5%) versus C (18%) (P less than 0.02); tip colonization (TC) was 17% in T versus 36% in C (P less than 0.01), while the incidence of septicemia (S) was also significantly less in T (2%) versus C (17%; P less than 0.01). S. aureus nasal carriers were at a threefold higher risk of SCC related septicemia (0.009/day) than noncarriers (0.003/day; P less than 0.05). The beneficial effect of PI ointment was most evident in this high risk group of S. aureus carriers: ES = 0% T versus 24% C, TC = 12% T versus 42% C, S = 0% T versus 29% C, P less than 0.05. There were no adverse effects of the treatment. The routine application of topical PI ointment to temporary hemodialysis catheter exit sites is effective in reducing SCC related infections.

Acute Kidney Injury↗
PubMed1991

Comparative analysis of health risk assessments for municipal waste combustors.

Quantitative health risk assessments have been performed for a number of proposed municipal waste combustor (MWC) facilities over the past several years. This article presents the results of a comparative analysis of a total of 21 risk assessments, focusing on seven of the most comprehensive methodologies. The analysis concentrates on stack emissions of noncriteria pollutants and is comparative rather than critical in nature. Overall, the risk assessment methodologies used were similar whereas the assumptions and input values used varied from study to study. Some of this variability results directly from differences in site-specific characteristics, but much of it is due to absence of data, lack of field validation, lack of specific guidelines from regulatory agencies, and reliance on professional judgment. The results indicate that carcinogenic risks are more significant than chronic non-carcinogenic risks. In most instances polychlorodibenzodioxins, polychlorodibenzofurans, and cadmium contribute more significantly to the total carcinogenic risk from MWC stack emissions than other contaminants. In addition, the contribution to total risk of all indirect routes of exposure (ingestion and dermal contact) exceeds that of the direct inhalation route for most studies reviewed.

Animals↗
PubMed1990

HTLV-I antibody studies in villagers in East Sepik Province, Papua New Guinea.

Serum samples collected in 1984 during a malariometric survey of two villages in the East Sepik Province of Papua New Guinea were tested for antibodies to HTLV-I. None of the villagers showed any symptoms suggestive of retrovirus infection. Eighteen of the 186 (9.5%) sera tested at that time were found to be positive. Blood samples were subsequently obtained from fifteen of the eighteen positives and subjected to analysis by enzyme-linked immunosorbent assay (ELISA), radioimmuno assay (RIA), radioimmunoprecipitation assay (RIPA), and Western blot (WB). Fourteen of the fifteen gave a positive ELISA response, but none were unequivocally positive by p 24 RIA. All sera tested were reactive to gag antigens by WB, but gave "indeterminate" results currently accepted criteria. Notably absent from the WB profiles of all of the study subjects was an antibody response to HTLV-I envelope protein gp 46. It is possible that these antibody responses are directed against a variant of HTLV-I or to a novel retrovirus which possesses core antigens similar to those of HTLV-I but has different envelope antigens. Until a virus is isolated, or the viral genome is identified in infected lymphocytes, the possibility remains that the response may be due to factors unrelated to retrovirus infection.

Adult↗
PubMed1989

A survey of the human T-cell lymphotropic virus type I (HTLV-I) in south-western Colombia.

To evaluate altitude of birthplace and residence as factors associated with geographic clustering of HTLV-I infection in Colombia, we sampled a total of 670 current residents of the South Pacific coastal lowland and of upland regions (Cali and environs) of the Valle and Cauca Provinces, located at an altitude of 3,100 ft. Among the 255 lowland study subjects, 4.3% had antibody against HTLV-I, compared to 0.9% of the 415 upland study subjects. A hypothesis emerging from this study is that the lower socio-economic status of lowland residents and associated diseases, particularly untreated syphilis and other sexually transmitted diseases, may explain the increased HTLV-I seropositivity rates in this population.

Adult↗
PubMed1989

Pulmonary function in preterm infants following treatment with intravenous indomethacin.

Pulmonary function tests, including measurements of arterial blood gas levels, total pulmonary compliance, and arterial-alveolar oxygen ratios, were performed in 38 ventilator-dependent preterm infants with respiratory distress syndrome who weighed less than 1500 g at birth. Twenty-seven had a physiologically significant patent ductus arteriosus (PDA). Twelve were assigned at random to receive three doses of intravenous indomethacin, 0.2 mg/kg per dose, on the fourth day of life. This treatment resulted in ductal closure in seven infants by the seventh day of life. Another concurrently observed group of 15 infants with PDA received no indomethacin. A third group of 11 infants lacked evidence of a PDA. Pulmonary function in the infants who received indomethacin did not differ significantly from that in the other two groups.

Ductus Arteriosus, Patent↗
PubMed1988

Abolition of actin-bundling by phosphorylation of human erythrocyte protein 4.9.

Protein 4.9, first identified as a component of the human erythrocyte membrane skeleton, binds to and bundles actin filaments. Protein 4.9 is a substrate for various kinases, including a cyclic AMP(cAMP)-dependent one, in vivo and in vitro. We show here that phosphorylation of protein 4.9 by the catalytic subunit of cAMP-dependent protein kinase reversibly abolishes its actin-bundling activity, but phosphorylation by protein kinase C has no such effect. A quantitative immunoassay showed that human erythrocytes contain 43,000 trimers of protein 4.9 per cell, which is equivalent to one trimer for each actin oligomer in these red blood cells. As analogues of protein 4.9 have been identified together with analogues of other erythroid skeletal proteins in non-erythroid tissues of numerous vertebrates, phosphorylation and dephosphorylation of protein 4.9 may be the basis for a mechanism that regulates actin bundling in many cells.

Actins↗
PubMed1988

Effects of clonidine on alprazolam discontinuation in panic patients: a pilot study.

Effects of adjunctive clonidine (0.15 to 0.7 mg/day) on symptoms experienced during and for 4 weeks after gradual alprazolam discontinuation were observed in panic disorder patients after 6 weeks of successful treatment. Twelve of 14 entered patients were considered to have had a sufficient period of discontinuation (2 weeks) and clonidine administration (1 week) for effects to be assessed adequately. Nine of these 12 patients reached zero dose of alprazolam in 3 to 4 weeks. However, 10 of 12 patients experienced new withdrawal symptoms and 11 of 12 experienced recurrent panic attacks during tapering. Although a greater proportion of patients were successfully discontinued in a shorter time than in a previous nonclonidine trial, clonidine did not appear to have a specific effect on relapse or withdrawal. A placebo-controlled trial is needed to discriminate between possible contributions of clonidine and other factors (e.g., physician attitude, placebo effect of pill taking) to this improved outcome.

Adult↗
PubMed1987

Copper staining: a five-minute protein stain for sodium dodecyl sulfate-polyacrylamide gels.

We present a new method for visualizing proteins electrophoresed in sodium dodecyl sulfate-polyacrylamide gels. After electrophoresis, gels are incubated in CuCl2 to produce a negative image of colorless protein bands against a semiopaque background. Gels are stained completely within 5 min, do not require destaining, and can be stored indefinitely without loss of the image. Because proteins are not permanently fixed within the gel, they can be quantitatively eluted after chelation of Cu with EDTA. The sensitivity of the CuCl2 stain falls between that of Coomassie blue and silver. We anticipate that CuCl2 will be useful in the rapid analysis of proteins by polyacrylamide gel electrophoresis and in the preparation of purified polypeptides by elution from gel slices.

Animals↗