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Biomedical subjects

A Levin

Publications and source records attributed to A Levin.

At least 145 records · Page 8Linked to original sources
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↗
PubMed1987

Discontinuation of alprazolam treatment in panic patients.

Alprazolam treatment was tapered in 17 panic patients at a rate of 10% of the starting dose every 3 days. Only four subjects completed withdrawal on schedule (4-5 weeks); four additional subjects discontinued treatment in 7-13 weeks. During withdrawal 15 patients had recurrent or increased panic attacks and nine had significant new withdrawal symptoms. Most common among the latter were malaise, weakness, insomnia, tachycardia, lightheadedness, and dizziness. None had seizures, psychosis, or significant neurological or EEG abnormalities. Results indicate that relapse and withdrawal are important considerations in the choice of alprazolam treatment for panic attacks.

Acute Disease↗
PubMed1986

Evidence for heterosexual transmission and clinical manifestations of human immunodeficiency virus infection and related conditions in Lusaka, Zambia.

In a hospital-based survey in Lusaka, Zambia, 189 (17.5%) of 1078 subjects had antibodies against the human immunodeficiency virus (HIV). The prevalence of antibodies was low in subjects aged less than 20 or greater than 60 years; in men the peak prevalence (32.9%) occurred in those aged 30-35 years, and in women (24.4%) it occurred in the 20-25 year age-group. There was no significant difference in prevalence by sex after adjusting for age. High educational level was independently associated with HIV seropositivity; the antibody against HIV was found in 18.4% of blood donors and in 19.0% of hospital workers. Among patients the antibody prevalence ranged from 8.7% in antenatal women and 9.3% in orthopaedic patients to 29.2% in those attending sexually transmitted disease (STD) clinics (the prevalence being 37.3% in previous attenders and 22.8% in first-time attenders). Seropositivity rates were higher in patients with an infectious problem (23.4%) than in those without (11.4%, p = 0.0002). Herpes zoster, oral thrush, diarrhoea, tuberculosis, and weight loss were independently correlated with seropositivity. The data strongly suggest that HIV infection is prevalent in Africa and is transmitted heterosexually. The restricted distribution of seropositivity to the sexually active age-groups indicates that the epidemic, at least in this part of Africa, is newly introduced; this has substantial implications for prevention.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Alprazolam in the treatment of panic disorders.

An open clinical trial of alprazolam therapy of patients with panic disorder or agoraphobia with panic attacks was undertaken to clarify certain issues not resolved by previous studies. These included the proportion of patients who significantly improve with alprazolam; the relative time courses for improvement in panic attacks, anticipatory anxiety, and phobic avoidance; whether successful alprazolam treatment alters vulnerability to panic with sodium lactate infusion; and what factors predict response to alprazolam in panic patients. Thirty patients meeting DSM-III criteria for panic disorder or agoraphobia with panic attacks completed a 12-week open clinical trial, and 22 were considered responders. In responders, panic attacks showed rapid improvement, whereas improvement of anticipatory anxiety and phobic avoidance was more variable. Successful alprazolam therapy appeared to block lactate vulnerability. High pretreatment Hamilton Anxiety Scale scores were associated with poor treatment response. The data suggest that alprazolam is an effective treatment for panic disorder and agoraphobia with panic attacks, and acts by directly blocking panic attacks.

Adult↗
PubMed1986

Phenelzine in social phobia.

Phenelzine was administered to 11 patients meeting DSM-III criteria for social phobia in open clinical trials. Seven of 11 showed marked improvement, while the remaining four experienced moderate benefit. These findings, which require replication in controlled trials, suggest that in addition to other actions, phenelzine has a direct effect in reducing interpersonal hypersensitivity.

Adolescent↗
PubMed1985

Mianserin is better tolerated and more effective in depression than a nomifensine-clobazam combination: a double-blind study.

Patients suffering from depression (mostly depressive neurosis) were admitted to a double-blind study which compared the efficacy of a combination of nomifensine and clobazam with mianserin. Therapeutic efficacy was evaluated on the Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Clinical Global Impression Scale, physician's assessments, Global Improvement and Treatment Emergent Symptom Scale for side-effects. Assessments were made before admission to the trial and on days 3, 7, 14 and 21. Forty patients were randomly allocated to two treatment groups. A case is made against polypharmacy and in particular against the use of benzodiazepine combinations in depression. Nineteen patients on nomifensine-clobazam and 14 on mianserin completed the three-week trial. At 7, 14 and 21 days, the Hamilton Depression Rating Scale (HDRS) total scores were significantly improved for mianserin when compared with nomifensine-clobazam. Similarly, at 7 and 14 days the Hamilton Anxiety Rating Scale (HARS) total scores were significantly better for mianserin than for the nomifensine-clobazam combination. There were also significant improvements for mianserin on the HDRS sub-scales of anxiety somatization, cognitive disturbance and sleep disturbance. There were no significant differences for HDRS somatic symptoms between treatment groups. Drowsiness was the most common side-effect in both groups. The incidence of total side-effects was 74% for nomifensine-clobazam and 71% for the mianserin group.

Adolescent↗
PubMed1985

Cardiac digital angiography: applications in ventriculography and coronary arteriography.

Clearly, computer-based digital subtraction offers several advantages over conventional approaches to contrast angiography. Using the newer method, in many situations contrast loads can be beneficially reduced, radiation exposure can be markedly diminished, and right ventricle evaluations can be simplified. In addition, storage of data on magnetic tape is less space consuming, and less costly, than storage on film. Over the 5- to 10-year life expectancy of a digitally equipped laboratory, these advantages probably justify the 30-50% increase in the initial monetary outlay for equipment in excess of that required for a conventionally equipped laboratory. However, the greatest promise of digital angiography is in the area of coronary arteriography. If three-dimensional reconstruction of coronary lesions and determination of regional flow can be effected, important advances in diagnosis and in prognostication theoretically might be expected, leading to more appropriate selection of therapy for individual patients than now can be achieved. However, currently available information does not yet indicate the extent to which such potential advantages will be realized. Thus, it will be several years before we will know whether the exciting potential of digital angiography in this area can be reached.

Angiography↗