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Biomedical subjects

G Pang

Publications and source records attributed to G Pang.

79 records · Page 5Linked to original sources
PubMed1986

Regulation of IgA secretion in polyclonally induced in vitro human lymphocyte cultures: the function of T and B cells from mesenteric lymph nodes and peripheral blood.

Human gut-associated immunoregulatory events were studied in a pokeweed mitogen (PWM)-stimulated culture system using lymphocytes obtained from the mesenteric lymph nodes (MLN) of female subjects undergoing gastroplasty for obesity. Compared with peripheral blood lymphocytes, lymphocytes obtained from MLN secreted IgG, IgA and IgM isotypes that differ in pattern and distribution despite similar proportions of T cells and B cells expressing isotype-specific surface membrane immunoglobulin (SmIg). Among the isotypes secreted, IgA appeared to be increased relatively to other isotypes in MLN cultures. Crossover coculture experiments using T and B cells isolated from both MLN and blood by E-rosetting and cell panning procedures demonstrated that IgA was particularly sensitive to help and suppression exerted by MLN T cells and T cell subsets defined by monoclonal antibodies OKT4 and OKT8 respectively, when compared with similar subsets isolated from blood. The results presented provide a basis for study of gut handling of ingested antigen in man, and of disturbed immunoregulatory events in inflammatory and neoplastic disease of the human gut.

Adult↗
PubMed1986

Quantitation of isotype specific Haemophilus influenzae antibody in serum and saliva of normal subjects and chronic bronchitics.

An immunoglobulin isotype specific radioimmunoassay procedure has been developed to assess the antibody response to Haemophilus influenzae somatic antigens in serum and mucosal secretions. This assay was reproducible (between assay CV% 13.9; within assay CV% 4.5 IgG, 3.9 IgA, 3.0 IgM) and specific for H1/H2 antigens. Different patterns of antibody were observed in healthy children (aged 5-10 years), adults and patients with chronic bronchitis. In serum, 20% of chronic bronchitics had antibody levels greater than those observed in healthy adults. In saliva, the proportion of chronic bronchitic patients with high levels (greater than 12% binding) of IgG specific antibody was significantly greater (P less than 0.05) than in healthy adults or children. The proportion of children and chronic bronchitics which had antibody levels of up to 4% binding was significantly greater (P less than 0.05) than that observed in healthy adults. A similar pattern was observed for IgM specific antibody. The occurrence of IgA specific antibody in the saliva in children and chronic bronchitics was consistently greater than that observed in adults for all levels of antibody (P less than 0.05). Chronic bronchitics with high levels of antibody had greater infection and mortality rates.

Adolescent↗
PubMed1983

Telangiectasias of the upper gastrointestinal tract. Report of six cases and review.

Telangiectasias of the upper gastrointestinal tract are probably being recognized more frequently now simply because of current high awareness of their existence. In six patients reported here, the condition was recognized in three because of recurrent upper gastrointestinal hemorrhage and in three during endoscopic evaluation for epigastric pain. Two of the six patients shared the features of gastric and/or duodenal telangiectasia, advanced age, and aortic valve disease. Two patients were treated with endoscopic coagulation, with no success in one. Laser, when available, may prove to be the most effective therapeutic tool for this entity.

Aged↗
PubMed1981

Immunoglobulin production in vitro by peripheral blood lymphocytes in systemic lupus erythematosus: helper T cell defect and B cell hyperreactivity.

Peripheral blood lymphocytes (PBL) from 16 patients with systemic lupus erythematosus (SLE) and 15 healthy control subjects were cultured and immunoglobulin (Ig) production in vitro was measured by immunofluorescent staining for intracytoplasmic Ig, a reverse haemolytic plaque assay to quantify cells secreting Ig and a solid-phase radioimmunoassay for Ig secreted into culture supernatants. Compared with normal PBL, lymphocytes from patients with SLE produced significantly fewer Ig-containing cells, Ig-secretion cells (ISC) and less Ig in supernatants in cultures stimulated by pokeweed mitogen (PWM). These differences were most pronounced during phases of disease activity. Culturing SLE PBL with a supernatant obtained from PWM-activated cultures of normal T lymphocytes partially restored their capacity to produce ISC. This observation suggests a helper T cell defect of SLE lymphocytes. In addition, PBL from patients with active SLE generated more ISC when cultured with Staphylococcus aureus bacteria (S aureus) than with PWM. S. aureus-stimulated cultures of SLE PBL also generated more ISC than PBL from normal individuals. The S. aureus response of SLE lymphocytes did not correlate with disease activity. As S. aureus is a T cell-independent mitogen, the latter observations suggest that in SLE an intrinsic B cell hyperreactivity may be a more persistent defect whereas T cell defects are transitory.

Adolescent↗
PubMedDate not supplied

Suppression of immunity to influenza virus infection in the respiratory tract following sleep disturbance.

The extent to which sleep deprivation interferes with immunity in the respiratory tract to influenza virus has been assessed in mice. Mice were orally immunized with influenza virus on two occasions separated by a one week interval and challenged intranasally one week later. Some animals were deprived of sleep for a 7 h period immediately following challenge. Three days after challenge, virus clearance and virus specific antibody were determined in lungs of sleep deprived and normally sleeping mice and the results compared with unimmunized mice subjected to the same protocol. Whereas immunized, normal sleep mice achieved total virus clearance, sleep deprivation in immunized mice completely abrogated this effect such that sleep deprived animals behaved as though they had never been immunized. There was no difference in viral clearance in unimmunized mice whether sleep deprived or not, indicating that sleep deprivation did not itself have a direct effect on viral replication. The data reported here support the concept that sleep is a behavioral state which is essential for optimal immune function in the presence of a respiratory tract pathogen.

Administration, Oral↗