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Biomedical subjects

J Hebert

Publications and source records attributed to J Hebert.

52 records · Page 3Linked to original sources
PubMed1984

The regulatory effect of histamine on the immune response: III. Defect on in vitro IgE production in atopics.

Spontaneous in vitro production of IgE was found higher in a group of untreated grass sensitive atopic patients than in normal volunteers when assessed at the cellular level with a reverse hemolytic plaque assay. This study also confirmed the increase of IgE synthesis after pokeweed mitogen stimulation in non-atopic donors and its decrease in atopic patients. Moreover, in this work we looked for a potential defect in immunoregulatory functions in atopic patients toward the in vitro IgE production. Indeed, histamine is known to activate suppressor cells capable, in turn, of suppressing IgG and IgE production from normal cells. In atopic patients, histamine could activate cells capable of suppressing IgG production but not IgE. Furthermore, similar findings were found when Concanavalin A-induced suppressor cells were examined. These findings suggest (a) a defective regulatory function towards IgE in atopic patients and (b) that the same subpopulation of suppressor cells seems to be activated by histamine and ConA and defective in atopic patients.

Antibody-Producing Cells↗
PubMed1983

Psoriatic arthritis: risk factors for patients with psoriasis - a study based on histocompatibility antigen frequencies.

Histocompatibility antigen frequencies were studied in a group of 100 patients with psoriatic arthritis (PSA) and were compared to a group of 80 patients whose psoriasis was restricted to skin lesions (PSC). The antigens B13, BW57 (17), CW6 were significantly increased in PSC while BW57 (17), BW39, CW6 and CW7 were increased in PSA. No DR or MT antigen was elevated in frequency when compared to normal controls. The significant information which results from this study includes: 1) a failure to confirm previous reports on HLA-DR antigen increased frequencies; 2) an association, in this population, of BW39 with PSA and not BW38; 3) finding of a closer link of PSC and PSA with HLA-C rather than HLA-B antigens; 4) an estimate of relative risk for patients with PSC to develop PSA.

Adolescent↗
PubMed1982

C3b inactivator deficiency with immune complex manifestations.

We report a complete C3b inactivator deficiency in a 28-year-old patient referred for bronchiectasis and recurrent pneumonia. In addition to these recurrent infections, previously described with this deficiency, he also had several immune complex manifestations (rheumatoid factor, circulating immune complexes and one episode of serum sickness). The consequences of C3b inactivator deficiency on complement activation, chemotaxis and opsonization, clearance of immune complexes, and on red blood cell sensitization are discussed. The study of the parents showed an autosomal dominant transmission.

Adult↗
PubMed1981

Characterization of lymphocytotoxic antibodies in renal transplantation.

Anti-B cell, anti-T cell, and antiperipheral blood lymphocyte antibodies were investigated in the sera from 115 cadaveric kidney graft recipients pre- and post-transplantation. These antibodies were characterized: optimal temperature for cytotoxicity (4 C or 22 C), immunoglobulin class (IgG or IgM), and reactivity after platelet absorption, and thereafter defined according to their influence on the graft survival. Patients with IgM anti-B cell antibodies, reacting mostly at 4 C, the activity of which could not be removed by platelet absorption, have a prognosis of the graft as good as those with no antibody, i.e., the graft function (serum creatinine and severity of rejection) at 3 years was comparable between those two groups. However, when the anti-B cell antibodies unabsorbable on platelets are of IgG class and detected at 4 C and 22 C, the graft outcome is poorer (P less than 0.025 at 3 months). A similar prognosis is observed in patients with antiperipheral blood lymphocyte antibodies of IgG or IgM class, absorbable or not on platelets (P less than 0.05). Lymphocytotoxic antibodies of the IgG class are always associated with a poor graft outcome. On another hand, the cold anti-B cell antibodies of the IgM class are not associated with graft failure but no enhancing effect could be seen.

Adolescent↗
PubMed1980

Pathological characteristics of good and poor interpersonal problem-solvers among psychiatric outpatients.

Contrasted good and poor interpersonal problem-solvers (N = 60), as defined by the Means-Ends-Problem-Solving Procedure (MEPS), on indices of psychopathological characteristics, as measured by the Millon Multiaxial Clinical Inventory (MMCI). The results suggest some support for a relationship between performance on the MEPS and psychological adjustment indices (MMCI); however, they do not offer an unambiguous interpretation. Significant differences were found between poor problem-solvers in contrast to good problem-solvers in the direction of relatively more maladjustment for poor problem-solvers. Significant differences were found between black-white good problem-solvers and also between black-white poor problem-solvers. Race may be an important moderator variable in performance on both the MEPS and the MMCI.

Adult↗
PubMed1978

Behçet's disease: possible role of secretory component deficiency, synovial inclusions, and fibrinolytic abnormality in the various manifestations of the disease.

Detailed study of four patients with BD, four controls with recurrent aphthous stomatitis, and 12 healthy controls has demonstrated markedly decreased levels of salivary SC in both its free and bound forms, and normal total protein concentration in BD salivas. In two BD patients, SC deficiency was also found in jejunal fluids. Depressed in vitro response of blood T cells to mitogens was also noted in BD. Levels of IgA in serum were normal, as well as total numbers of T cells and IgA-carrying B cells in blood. A fluid phase abnormality of the fibrinolytic system as tested by the clot lysis assay was demonstrated in the blood from BD patients. Studies of BD SF and synovial membrane by light and electron microscopy showed inclusions composed of degenerated neutrophils inside monocytes. Abnormalities of host defense mechanisms at the mucous membrane level due to SC deficiency, together with a systemic T cell functional defect and fibrinolytic abnormality, could be important mechanisms in the pathogenesis of recurrent mucosal ulcers and thrombosis in BD.

Behcet Syndrome↗
PubMed1976

Evaluation of an automated procedure for primary screening of hyperlipoproteinemias.

An automated procedure for the determination of beta-plus-pre-beta-lipoprotein cholesterol is described and evaluated for mass screening of hyperlipoproteinemias. It is shown that this method fulfills the requirements for an ideal method for primary screening: it can be used in non-fasting samples, is capable of detecting hyperlipoproteinemias characterized by both cholesterol and/or triglyceride abnormalities, is fast, accurate and extremely inexpensive. Evidence is shown that the method is extremely useful for primary screening and, when tested in a coronary screening detection program, gave only 4% false positive and 3.4% false negative results.

Autoanalysis↗
PubMed1975

Superior recall of letters in the right visual field with bilateral presentation and partial report.

The present investigation addresses itself to the question of whether a right visual field effect would emerge under conditions of bilateral letter presentation and partial report. Tachistoscopic trials consisting of eight letters, four in each field, were presented for 100 msec., to twenty right-handed adults. Ss were instructed to report the content of only one field on each trial. Under these conditions a right field superiority was obtained and an interaction between field and stimulus position. The field asymmetry appears to reflect the operations of cerebral dominance while the interaction suggests the influence of mnemonic factors.

Brain Mapping↗
PubMed1975

Cellular and humoral immune parameters of synovial fluid and blood in rheumatoid arthritis.

Thymus derived (T) and bone marrow derived (B) cells from joint fluid and peripheral blood of 15 patients with rheumatoid arthritis and 10 controls with other inflammatory joint diseases were studied. High absolute numbers and high percentages of T cells in the synovial fluid, T plus B cell sums exceeding 100 per cent in synovial fluid or blood, and fewer complement receptors compared to surface Ig bearing cells in joint fluid or blood was found only in rheumatoid arthritis. T and B cell numbers did not correlate with disease activity. No differences in T and B cells were found between patients positive or negative for rheumatoid factor. (J Rheumatol 2: 363-372, 1975).

Adult↗
PubMed1975

Modulation of HL-A antigens by anti-HLA antiserum: effects on the cytotoxicity assay and mixed leukocyte reaction.

Modulation of human leukocyte antigen (HLA) was attempted by treating leukocytes with specific anti-HLA antiserum or by their passage through columns coated with anti-HLA or a double layer of HLA-anti-HLA. The modulated cells were resistant to the cytotoxic effects of the anti-HLA, and they were poor stimulators and good responders to allogeneic cells in the unidirectional mixed leukocyte reaction. Modulated cells regained their HLA 16 hr after modulation if kept in cell suspension alone. The proliferative responses of modulated cells to mitogens were as good as non-modulated cells, indicating that modulation was probably not caused by depletion of lymphoid cells. Supernatants of modulated cells that were incubated overnight or preformed HLA-anti-HLA complexes were capable of suppressing and enhancing the MLR of specific cells depending on the dose used. The similarities of modulation of HLA to other lymphocyte receptors and the limitation of application of the modulation phenomenon to transplantation of allogeneic cells are discussed.

Antibody Specificity↗
PubMedDate not supplied

Attitudes toward risk factor behavior of relatives of cancer patients.

BACKGROUND: Targeted health promotion requires an identifiable subpopulation which is accessible, at increased risk, receptive to input, and receptive to change. Relatives of recently diagnosed cancer patients may meet these criteria and have not previously been investigated as recipients of preventive education regarding smoking and diet. METHODS: This study investigates these factors, beliefs regarding perceived susceptibility to cancer, and attitudes toward behavior change in 101 relatives of 50 patients with smoking-related cancers, breast cancer, and other diet-related cancers. Congruence of attitudes between patients and relatives, another possible factor in changing health behaviors, also was assessed. RESULTS: Access to relatives of patients was very high, as was their willingness to discuss these issues (99% of relatives contacted participated in the survey). Relatives' ratings of relevant risk factors were generally higher than those of patients; ratings of their own vulnerability were moderate. Within diagnostic groups, there was high concordance of belief between patients and relatives for certain types of risk, such as heredity for breast cancer (r = 0.81) and smoking for smoking-related cancers (r = 0.52), but not for dietary factors. CONCLUSIONS: The high level of access suggests that relatives may be receptive to discussing issues of behavior risk and change. They are at least as aware as patients of cancer risk factors. Spontaneous behavior change was very low. They may therefore be good candidates for targeted health promotion regarding cancer risk.

Adult↗
PubMedDate not supplied

16alpha-bromoepiandrosterone, a dehydroepiandrosterone (DHEA) analogue, inhibits Plasmodium falciparum and Plasmodium berghei growth.

Dehydroepiandrosterone (DHEA) and its analogue, 16alpha-bromoepiandrosterone (alpha-epi-Br), may have activity against viral and parasitic infections, including human immunodeficiency virus (HIV) and Cryptosporidium parvum. Therefore, we evaluated its antimalarial effects on Plasmodium falciparum and Plasmodium berghei. In vitro, chloroquine (CQ)-sensitive and resistant strains of P. falciparum parasitized red blood cells were incubated with escalating doses of alpha-epi-Br or CQ. In vivo, 62 rats were infected with P. berghei and treated with CQ or alpha-epi-Br. At the highest doses tested against a CQ-sensitive strain, parasitemias decreased from 25.4% in the saline control group to 4.3% and 4.8% in the alpha-epi-Br and CQ groups, respectively (P < 0.05). Against two CQ-resistant strains, parasitemias decreased from 22.3-28.8% and 24.8-30% in the CQ and saline groups, respectively, to 2.5-2.7% in the alpha-epi-Br groups (P = 0.003). In vivo, on Day 4, parasitemias decreased from 23% in the saline group to 9-12% and 12% in the in alpha-epi-Br and CQ groups, respectively (P < 0.05). These data demonstrate that alpha-epi-Br shows activity against CQ-sensitive and resistant strains of P. falciparum in vitro. At the doses tested against P. berghei in vivo in rats, alpha-epi-Br is comparable to CQ.

Androsterone↗
PubMedDate not supplied

Predictive value of anti-DNA antibody and selected laboratory studies in systemic lupus erythematosus.

In a retrospective study of 71 patients with systemic lupus erythematosus (SLE), a large number of clinical and laboratory variables were studied in order to determine their predictive value of morbidity and mortality. Patients were followed for an average of 57 months. Anti-DNA antibody, hemoglobin and creatinine levels at initial evaluation correlated significantly (p less than 0.05) for subsequent course of SLE, although each parameter was not a good predictor for final outcome. Anti-DNA correlated better with subsequent course in patients who were diagnosed within 12 months of the initial evaluation. By comparison, other measured parameters were not predictive at all. Anti-DNA, hemoglobin, creatinine and C3 levels at the time of most recent evaluation (date last seen) correlated strongly (p less than 0.01-p less than 0.001) with concurrent clinical status.

Antibodies, Antinuclear↗