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Biomedical subjects

A Moss

Publications and source records attributed to A Moss.

At least 73 records · Page 4Linked to original sources
PubMed1991

Lack of evidence of occult human immunodeficiency virus in seronegative individuals at very high risk of infection.

Reports of human immunodeficiency virus (HIV) infection in seronegative individuals prompted the authors to investigate subjects who are at very high risk of acquisition of HIV in San Francisco. Nine HIV seronegative subjects were evaluated extensively, eight of whom were drawn from a well-characterized cohort of seropositive and seronegative homosexual men who have been followed prospectively since 1983-1984. These men have calculated probabilities of infection based on a fitted model of between 0.22 and 0.94. One additional subject is an intravenous drug user who has shared needles with HIV-infected individuals extensively. Peripheral blood lymphocytes and monocytes were separately cultured from each subject and evidence of HIV infection was sought by a reverse transcriptase assay, enzyme immunoassay, and immunocytofluorographic analysis for HIV antigens, in situ hybridization, RNA slot blot analysis, and polymerase chain reaction amplification of HIV cDNA. Uncultured monocytes and lymphocytes from each donor were also examined by these techniques. Evidence of HIV infection was not found in the peripheral blood mononuclear cells of these high risk individuals.

DNA, Viral↗
PubMed1991

Dissociable face processing impairments after brain injury.

Matched populations of head-injured patients and normal control subjects completed three "forced-choice" face processing tasks designed to test facial expression recognition, familiar face recognition, and unfamiliar face matching. We hypothesised a significant difference in the performance of the patients and controls on the three tasks, and hoped to observe individual differences in the patients' performance across tasks. As predicted the head-injured patients made significantly more errors than the controls on the forced-choice tasks. Four cases of dissociable impairments affecting only one of the face processing tasks are reported; patient JP impaired only on facial expression recognition, patients AB and HI impaired only on familiar face recognition, and patient VS impaired only on unfamiliar face matching. These dissociable impairments provide further evidence for independent cognitive processing of specific face properties.

Adult↗
PubMed1991

Human T cell lymphotropic virus types I and II in intravenous drug users in San Francisco: risk factors associated with seropositivity.

Serologic assays for human T cell lymphotropic virus types I and II (HTLV I/II) infection were done in 676 intravenous drug users (IVDUs) in San Francisco between 1985 and 1987: 150 in 1985, 44 in 1986, and 482 in 1987. All sera were tested by Western blot, ELISA, and p24 RIA. A total of 111 participants were seropositive in a minimum of two assays. Duration of intravenous heroin use was strongly associated with the risk of HTLV I/II seropositivity: greater than or equal to 21 years odds ratio, 6.1 (95% confidence interval [CI], 2.2-17.5), compared with less than 10 years of heroin use. Additional independent risk factors included black or Hispanic race, female sex, and the use of drugs in a shooting gallery. Coinfection of HTLV I/II and human immunodeficiency virus was less frequent than expected by chance (P less than .02). Longitudinal specimens were available in 154 participants. The age- and race-adjusted seroconversion rate was 3.4% (95% CI, 1.3-8.9) per person per year. Of the 349 homosexual men tested, none were HTLV I/II-seropositive.

Adult↗
PubMed1991

Population-based estimates of zidovudine and aerosol pentamidine use in San Francisco: 1987-1989.

From the San Francisco Men's Health Study (SFMHS) and the San Francisco General Hospital Cohort we derived partially population-based estimates of zidovudine (ZDV) use in San Francisco from 1987 to 1989. Data from the SFMHS alone were used to make estimates of aerosol pentamidine (AP) use in 1989. From 1987 to 1989, zidovudine use increased from 36 to 68% in participants with AIDS. In participants with symptomatic HIV infection without AIDS and in those with less than 200 CD4 cells, ZDV use increased initially but then leveled off (from 6 to 25% and 24 to 55%, respectively). Zidovudine use with more than 500 CD4 cells increased from 0.5 to 4%. In 1989 AP use with less than 200 CD4 cells was 42% and with AIDS was 44%. Whereas 50% of participants with AIDS and less than 200 CD4 were using both ZDV and AP, only 14% of those without AIDS but with less than 200 CD4 cells were using both. Surprisingly few members of these cohorts are using therapies proven effective in reducing the morbidity and mortality of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Acute effects of insulin-like growth factor I and insulin on glucose metabolism in vivo.

We have compared the actions of insulin-like growth factor (IGF-I) and insulin on glucose metabolism in vivo, using the glucose clamp technique in rats. Both hormones caused dose-dependent inhibition of hepatic glucose production, stimulation of whole body glucose disposal, and an increase in the glucose metabolic rate of specific muscles. Infusion of IGF-I also decreased the plasma concentration of insulin. An an infusion rate of 0.57 nmol.kg-1.min-1, IGF-I led to stimulation of whole body glucose uptake that was similar to the glucose uptake produced by infusion of 0.01 nmol.kg-1.min-1 insulin. The glucose metabolic rate, as measured by 2-deoxy-D-glucose uptake, was comparable in quadriceps femoris, soleus, and diaphragm muscles during the infusion of 0.57 nmol.kg-1.min-1 IGF-I and 0.01 nmol.kg-1.min-1 insulin. However, at these rates of infusion, IGF-I caused only a 38 +/- 6% inhibition of hepatic glucose output compared with 66 +/- 12% inhibition by insulin (P less than 0.05). Thus, under these conditions, muscle is more responsive than liver to IGF-I, which agrees with the complement of IGF-I receptors in the two tissues.

Animals↗
PubMed1989

Distribution of insulin receptor-like immunoreactivity in the rat forebrain.

Previous studies have suggested that insulin may play a role in the hormonal regulation of neurotransmitter metabolisms within the central nervous system. In order to provide additional information to support this hypothesis, we examined the distribution of insulin receptors within the forebrain of adult male rats. Insulin receptors were localized by immunocytochemistry, using an antibody directed against the carboxy-terminus of the beta-subunit of the insulin receptor. The antibody specificity was tested by immunoprecipitation of brain insulin receptors with antiserum and the purity of the receptor-antibody preparation was determined using hormone binding-assays with radiolabeled insulin and insulin-like growth factor-l. Insulin receptor-like immunoreactivity was found in a widespread, but selective, distribution on neurons throughout the rat forebrain. Double-labeling with glial fibrillary acidic protein did not demonstrate any detectable insulin receptor-like immunoreactivity on glial cells. Areas with the highest density of insulin receptor-like immunoreactivity were found in the olfactory bulbs, hypothalamus and median eminence, medial habenula, subthalamic nucleus, subfornical organ, CA 1/2 pyramidal cell layer of the hippocampus and piriform cortex. Double-staining of hypothalamic sections with somatostatin and vasopressin antisera revealed insulin receptor-like immunoreactivity on a subpopulation of somatostatin neurons in the periventricular region and on vasopressin neurons in the supraoptic nucleus. A moderately dense insulin receptor-like immunoreactivity was observed in layers II-IV of cerebral cortex, medial amygdala, reticular thalamic nucleus, zona incerta, and preoptic and septal regions, whereas a low density of insulin receptor-like immunoreactive neurons was found in basolateral amygdala and most thalamic regions. The basal ganglia and most parts of the thalamus were almost devoid of insulin receptor-like immunoreactivity. Our findings provide morphological support for a direct action of insulin on selected regions of the rat forebrain and suggest that the insulin receptor may modulate synaptic transmission or the release of neurotransmitters and peptide hormones in the CNS.

Animals↗
PubMed1989

Serum beta 2-microglobulin decreases in patients with AIDS or ARC treated with azidothymidine.

Abnormally elevated serum beta 2-microglobulin has been associated with progression of human immunodeficiency virus (HIV) disease and could reflect in vivo HIV activity. We prospectively studied the effect of azidothymidine therapy on serum beta 2-microglobulin concentration in 41 patients with AIDS or AIDS-related complex. Median beta 2-microglobulin concentration decreased from 4.02 mg/L before therapy to 3.73 mg/L at week 24 of therapy (P = .016). Individual changes in beta 2-microglobulin during azidothymidine therapy correlated with changes in serum HIV p24 antigen (Spearman, r = .42, P = .007). Also, in a randomized placebo-controlled study, median beta 2-microglobulin concentration decreased after 16 w of therapy in 5 azidothymidine-treated patients compared with levels in 7 placebo-treated controls (P = .05). Serum beta 2-microglobulin appears to be a sensitive marker for in vivo antiretroviral drug activity and may be a better marker than serum p24 antigen for early intervention trials involving antiretroviral agents.

AIDS-Related Complex↗
PubMed1988

Prospective study of catheter-related infection during prolonged arterial catheterization.

Ninety-six arterial catheters from 75 different anatomical sites in 56 surgical ICU patients were studied prospectively to determine the rate of catheter-related infection associated with prolonged arterial catheterization (defined as greater than 96 h). Every 96 h, all catheters were semiquantitatively (SQ) cultured and the percutaneous entry site was swab cultured. Sites were used indefinitely by exchanging the catheters over a guide-wire every 96 h as long as arterial monitoring was necessary and SQ cultures remained negative (less than or equal to 15 colonies). No sites used less than 96 h developed skin colonization, while 14/51 (27%) sites used greater than 96 h developed positive swab cultures. No SQ cultures were positive in sites with negative swab cultures (p less than .001). Catheter-related infection (a positive SQ culture) developed in 4/42 (9.5%) radial or femoral sites compared to 4/9 (44%) axillary sites used greater than 96 h (p less than .01). It is concluded that arterial catheter-related infection develops in less than 10% of radial or femoral sites used greater than 96 h, and 90% of radial and femoral sites may be used safely for prolonged periods if skin colonization at the percutaneous sites is controlled and SQ catheter cultures remain negative. Skin site swab cultures may be useful for determining when arterial catheters should be removed and SQ cultured.

Arteries↗
PubMed1987

CT body stereotaxic system for placement of needle arrays.

A new CT body stereotaxic system that is particularly suited to multiple placements of needles precisely in parallel is described. By scanning through a right triangle placed on the patient's skin, the stereotaxic method defines an entry point for the first needle placement. An articulating arm is then used to aim the needle at the entry point and hold the needle at the correct angle. The arm can be angled so that the complex approaches from one scan plane to another can be made to place needle arrays through inaccessible lesions, for instance, beneath the diaphragm. Animal and phantom studies have shown that placement of multiple needle arrays in parallel from CT scan data is possible.

Biopsy, Needle↗
PubMed1987

Exposure to hair dyes and polychlorinated dibenzo-p-dioxins in AIDS patients with Kaposi sarcoma: an epidemiological investigation.

Fifty male AIDS patients with Kaposi sarcoma and 50 matched controls were interviewed about occupation, exposure to pesticides, Vietnam service, smoking habits, etc. No difference in use of pesticides was seen. One case but no control had served in Vietnam and was thereby exposed to agent orange. Dioxins are known to be immunosuppressive in animals. No significant difference in exposure to dioxin-containing products was found between cases and controls, however. Of interest was the fact that four cases but no control were occupationally exposed to hair dyes, some of which have been reported to be carcinogenic.

Acquired Immunodeficiency Syndrome↗