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Biomedical subjects

J Hewitt

Publications and source records attributed to J Hewitt.

At least 91 records · Page 5Linked to original sources
PubMed1982

The use of murine monoclonal antibodies without purification of antigen in the serodiagnosis of tuberculosis.

A serum diagnostic test for tuberculosis has been devised on the basis of competitive inhibition by human sera of the binding of 125I-labelled murine monoclonal antibodies (Mabs) to a solid-phase bound pressate of M. tuberculosis. Five monoclonal antibodies binding to distinct antigenic determinants of the organism were used as structural probes which conferred their stringent combining site specificities to the polyclonal mixture of human antibodies. Sera from patients but not from healthy controls competed effectively with the binding of 125I-labelled Mabs to M. tuberculosis-coated polyvinyl plates. This inhibition technique eliminated the need for elaborate purification of antigen used in previous serological methods. Some Mabs gave considerably more positive results than others. The best combination of tests used 2 Mabs and yielded a positive result in 71% of 41 patients with smear-positive pulmonary tuberculosis. This approach is applicable in principle to the serodiagnosis of other human bacterial diseases.

Animals↗
PubMed1982

[Kaposi's disease. 2 recent cases].

Known since 1872, the multifocal angiosarcoma called Kaposi's sarcoma takes different forms in different communities. It develops slowly among the mediterranean populations and Jewish Central Europe and most rapidly among Bantus, in Africa, and white homosexuals. Another aspect of the disease has been described in patients with transplanted kidney, where it seems to be associated with immunosuppressive treatments. The recent outbreak of Kaposi's sarcoma among homosexuals in New York and San Francisco raises new and difficult problems concerning its aetiology, as the outbreak cannot be entirely explained by pressure from sexually transmissible diseases. Having observed two new cases in France, the authors have attempted to re-evaluate the pathophysiological factors of the disease, the most constant of which seems to be a considerable degree of immunodepression, perhaps partly due to chronic infection.

Adult↗
PubMed1982

Activation of beta-galactosidase by monoclonal antibodies.

Four monoclonal cell lines secreting antibodies that activate the beta-galactosidase protein from lac-aba strains of Escherichia coli have been isolated. One of the antibodies, BG 79, inhibits the normal beta-galactosidase from E. coli in addition to its activation of the protein from mutants. Moreover, when in combination with any of the other activating antibodies, BG 79 exhibits synergistic activation of the beta-galactosidase protein, and the synergistically activated enzyme is stimulated by methanol, although most of the proteins activated by single antibodies are inhibited by methanol. The equilibrium of binding of BG 79 to the beta-galactosidase protein is not affected by the presence of a second antibody, and the half-time for activation by BG 79 is only slightly, though significantly, increased by preincubation of the protein with the second antibody. Our results imply that activation of beta-galactosidase proteins is not a simple correction of a conformational defect, and that many distinct active conformations are available to the enzyme.

Antibodies, Monoclonal↗
PubMed1982

Differential reaction to touch by men and women.

An experimenter placed biofeedback electrodes on seven different locations of each subject's body. The electrodes were held in place by the experimenter for 2 min. (at each location) after which the subject rated his or her degree of comfort-relaxation. A three-factor design was employed in which the variables were touch type (hand top, forearm top and bottom, upperarm top and bottom, shoulder, back), sex of subject, and sex of experimenter. It was assumed that males would react more adversely to same-sex touch than would females when the type of touch was typical of female-female interactions (hand or arm touch) but not when the touch was typical of male-male interactions (shoulder or back touch). Results were consistent with expectations.

Adult↗
PubMed1982

[Hyperkeratosis of the keratotic plug type in patients with chronic renal failure and metabolic diseases].

We have noticed in eight male patients transepithelial keratotic plugs which appeared preferentially on zones of supporting points. These plugs evoked in a more or less accurate way, Kyrle's disease or other related syndromes, particularly reactive perforating collagenosis and perforating folliculitis. Seven cases were associated with chronic and severe renal failure complicating a serious diabetes in four cases, one of them with a viral hepatitis. One case has been observed during an important denutrition with digestive disorders.

Adult↗
PubMed1981

The large high mobility group proteins of rainbow trout are localized predominantly in the nucleus and nucleoli of a cultured trout cell line.

On the basis of immunofluorescence and biochemical studies, it has been suggested that the concentration of nonhistone chromosomal protein high mobility group 1 may be higher in the cytoplasm than in the nucleus of mammalian cells (Bustin, M., and Neihart, N. K. (1979) Cell 16, 181-189). In view of the possible implications of this finding, we have examined the in situ location of trout proteins HMG-T1 and HMG-T2, which are analogous to the mammalian proteins HMG-1 and HMG-2. Antibodies prepared against purified HMG-T2 were shown to react only with HMG-T1 and HMG-T2, but not with any other chromosomal proteins from trout. This has been established using a modified immunoautoradiographic techique involving CNBr-activated paper transfers of proteins separated on regular sodium dodecyl sulfate-polyacrylamide gels. Using the indirect immunofluorescence technique to examine the subcellular location of HMG-T (T1 and T2) proteins in a cultured cell line of rainbow trout, we find that these proteins are located primarily in the nucleus of these cells. The fluorescence in the nucleolar regions is even more intense than in the nonnucleolar regions. The cytoplasmic regions show only a weak fluorescence which may be due to low levels of HMG-T proteins in the cytoplasm, since preincubation of anti-HMG-T2 with purified HMG-T2 abolishes the nuclear as well as cytoplasmic fluorescence.

Animals↗
PubMed1981

Fetal metabolic response to experimental placental vascular damage.

The fetal metabolic response to repetitive placental damage, produced by microsphere embolization of the uteroplacental circulation, was examined longitudinally in eight singleton fetal lambs and compared with similar data from seven controls. Significant morphometric fetal growth retardation was associated with an abrupt cessation of the normal increases in oxygen, glucose, and lactate uptake observed in the control animals. However, fetal blood levels and umbilical substrate quotients did not change. At the time of sacrifice, fetal oxidative metabolic rate was reduced significantly. The significance of these findings relative to intact fetal survival is discussed.

Animals↗
PubMed1981

Effect of anti-inflammatory drug administration in patients with rheumatoid arthritis. An endoscopic assessment.

A prospective endoscopic study was carried out in 65 patients with rheumatoid arthritis to assess the prevalence of gastroduodenal lesions on aspirin alone or aspirin plus another anti-inflammatory drug (n = 26). All patients were taking greater than or equal to 8 tablets aspirin/day for greater than or equal to 3 months. Drug therapy consisted of regular, buffered or enteric-coated aspirin +/- one other non-steroidal anti-inflammatory drug or less than or equal to 10 mg prednisone/day. Endoscopic findings were graded as normal, or gastric and/or duodenal erythema, erosions, or ulcer; only the most serious lesion was tabulated. Fifty-three percent of patients on aspirin alone has a gastric ulcer or erosions, and 13% duodenal ulcer or erosions compared to 35% with gastric lesions and 4% with duodenal lesions on aspirin plus a second drug. Twenty-two percent of patients taking regular aspirin had gastric ulcers compared to only 6% taking enteric coated. Patients on enteric coated aspirin and prednisone had only a 10% prevalence of severe gastro-duodenal lesions. In conclusion, the combination of a second anti-inflammatory drug and aspirin therapy did not result in a higher prevalence of gastro-duodenal damage over that produced by aspirin therapy alone. Enteric coated aspirin produced significantly fewer serious lesions than regular or buffered aspirin. The combination of enteric-coated aspirin plus low dose prednisone caused a low prevalence of severe gastro-duodenal lesions.

Anti-Inflammatory Agents↗
PubMed1981

Infective endocarditis-associated glomerulonephritis in rabbits: evidence of a pathogenetic role for antiglobulins.

Serial studies of circulating immune complexes, serum complement, proteinuria and renal histology and immunofluorescence have been undertaken in infective endocarditis glomerulonephritis in rabbits. Eighteen of 24 rabbits developed evidence of glomerulonephritis and 13 of 18 had circulating immune complexes. Gel filtration studies showed the immune complexes to have a size range of ca 4.10(6)--3.10(5) daltons. Direct immunofluorescence staining of glomeruli showed that IgM was the predominant immunoglobulin present and that antiglobulin activity was associated with IgM deposition. Intraglomerular localization of antiglobulin was closely associated with evidence of glomerulonephritis. Streptococcal antigen(s) were not demonstrable in glomeruli, even after acid elution of sections.

Animals↗