Biomedical subjects

V Gant

Publications and source records attributed to V Gant.

22 records · Page 2Linked to original sources

PubMed1992

Alveolar macrophage accessory cell function in bronchial asthma.

The capacity of peripheral blood monocytes and alveolar macrophages (AM) obtained by bronchoalveolar lavage (BAL) to present recall antigens, namely, tuberculin purified protein derivative (PPD) or streptokinase-streptodornase (SKSD), to highly purified autologous T-cells has been studied in 11 asthmatic and 11 healthy, nonatopic normal subjects. In the asthmatic group, AM accessory cell function was variable, and most subjects were unable to present either recall antigen as effectively as blood monocytes, although one asthmatic subject demonstrated larger proliferative responses than blood monocytes for both antigens. AM accessory cell activity was not antigen-specific, and there was a correlation between accessory cell efficacy for the two antigens (r = 0.92; confidence interval, 0.53 to 0.98). Furthermore, a correlation existed between the percentage lymphocyte count in the BAL fluid and the ratio of macrophage to monocyte antigen-presenting capability for both PPD (r = 0.92; 95% confidence interval, 0.83 to 0.99) and SKSD (r = 0.90; 95% confidence interval, 0.45 to 0.98). In the normal subjects, AM were also unable to act effectively as accessory cells for the presentation of PPD and SKSD in the majority of subjects. No correlation existed between the percentage lymphocytes in BAL fluid and the ratio of AM to monocyte accessory cell function. These results suggest an association between AM accessory function and the presence of BAL lymphocytes in bronchial asthma.

Adult↗

PubMed1992

The immunogenetics of early nephropathy in insulin-dependent diabetes mellitus: association between the HLA-A2 antigen and albuminuria.

One-hundred and seventy-two normotensive, insulin-dependent diabetic patients without clinical proteinuria (Albustix negative) were typed for the major histocompatibility complex class I (HLA-A, -B) and class II (HLA-DR) antigens. Urinary albumin excretion was measured as the albumin:creatinine ratio (UA/UC, mg/mmol) in an early morning sample. Patients expressing the HLA-A2 antigen had significantly higher UA/UC values than those not expressing the antigen. The observed ratio of geometric means was 1.77 (95 per cent confidence interval (CI) 1.18-2.67; p < 0.01); the relative risk of microalbuminuria (UA/UC > 3.0 mg/mmol) associated with expression of HLA-A2 was 2.52 (95 per cent CI 1.11-5.73; p < 0.05). There was no significant association between UA/UC and HLA-B8, -B15, -DR3, -DR4 or other antigens. Patients were re-studied after a mean period of 5.3 years: multiple linear regression analysis showed that the UA/UC at this time was positively related to the initial glycosylated haemoglobin level (p < 0.01) and expression of the HLA-A2 antigen (p < 0.05), but not to blood pressure or creatinine clearance. Fifteen patients developed macroalbuminuria at follow-up (UA/UC > 45.5 mg/mmol). Compared with a group matched for age, sex, duration of diabetes, and glycosylated haemoglobin who did not develop macroalbuminuria, macroalbuminuric patients had a higher frequency of HLA-A2 (p < 0.01). The odds ratio of progressing to macroalbuminuria associated with HLA-A2 had a 95 per cent CI of 1.71 to infinity. We conclude that an immunogenetic factor may play a role in the development of early diabetic nephropathy and that the risk associated with expression of the HLA-A2 antigen is independent of metabolic control and blood pressure.

Adolescent↗

PubMed1990

Recurrent urticaria and reduced diamine oxidase activity.

An abnormal metabolism of histamine has been suspected in urticaria and the role of diamine oxidase (DAO: histaminase) is therefore of interest. We have studied DAO activity in plasma and jejunal biopsy material and have measured the post-heparin DAO release in 11 control subjects and nine with recurrent urticaria, three of whom had had concurrent episodes of abdominal pain. Two of the nine urticaria subjects had only a minimal rise in plasma DAO activity after heparin, three had a response which was at the lower end of the normal range, and four were normal. In four out of five cases in which jejunal biopsy activity was obtained, there was concordance between mucosal DAO activity and the post-heparin plasma DAO response. Those with abdominal symptoms had abnormally low mucosal DAO activity and the subject who was most severely affected had proven episodes of small bowel oedema.

Adult↗

PubMed1990

Identification of lipoxin A4 and its relationship to the sulfidopeptide leukotrienes C4, D4, and E4 in the bronchoalveolar lavage fluids obtained from patients with selected pulmonary diseases.

Lipoxins are biologically active trihydroxytetraene containing products derived from arachidonic acid that are formed by interactions between lipoxygenases. Although the lipoxins have been generated from mixed cell suspensions in vitro, it has not been established whether these products are synthesized in vivo. We have performed bronchoalveolar lavage (BAL) in 12 patients with lung disease (sarcoid, six; pneumonia, two; asthma, two; carcinoma, one; alveolitis of unknown cause, one) and in six normal control subjects. The BAL fluid was analyzed for lipoxin A4 (LXA4) using gas chromatography mass spectrometry with selective ion monitoring, and the levels of the sulfidopeptide leukotrienes were determined using reverse-phase high-performance liquid chromatography and radioimmunoassay. LXA4 was detected in BAL fluid from nine of the 12 patients studied. The levels of LXA4 ranged from 0.4 to 2.8 ng/ml. LXA4 was not detected in any of the six normal subjects. Sulfidopeptide leukotrienes were detected in all the BAL samples, ranging from 0.04 to 0.7 ng/ml, and there was no significant difference between the patients and the normal subjects. In patients with detectable LXA4 in BAL fluid, the ratio of the concentrations of LXA4 to those of the sulfidopeptide leukotrienes ranged from 1.9 to 62 (mean, 19.0). This is the first demonstration of the presence of LXA4 in disease.

Adult↗