Search PubMed⌕ Search

Biomedical subjects

B S Rabin

Publications and source records attributed to B S Rabin.

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

Stressor-induced changes in mitogenic activity are not associated with decreased interleukin 2 production or changes in lymphocyte subsets.

Splenic lymphocytes from Lewis rats that received presentations of physically aversive electric shock demonstrated a marked reduction in responsiveness to T-cell mitogens such as concanavalin A. This study examined cellular mechanisms which may be responsible for this functional alteration. There was no difference in distribution of T-cell subsets from shocked and nonshocked rats. There was no difference in the production of interleukin 2 (IL-2) nor was there a difference in the percentage of IL-2 receptor positive T cells or T-cell subsets after culture for 24 hr. However, there was a marked lack of mitogenic stimulation in splenocytes from shocked rats when stimulated with the calcium ionophore A23187. This indicates a defect in the biochemical pathways necessary to activate T-cell mitogenesis.

Animals↗
PubMed1991

Familial and sporadic insulin-dependent diabetes: evidence for heterogeneous etiologies?

Heterogeneity within insulin-dependent diabetes mellitus (IDDM) has been hypothesized, but few studies have focused on differences which may exist between familial and sporadic IDDM cases. Presenting characteristics for 330 white, newly diagnosed IDDM cases were evaluated. Familial cases were older (10.2 +/- 5.1 years vs 7.9 +/- 4.2 years, P = 0.010) and had, on average, less severe metabolic disturbances at presentation, as demonstrated by lower mean hemoglobin A1 (12.6 +/- 2.4% vs 14.4 +/- 2.6%, P = 0.001) and mean insulin dose at discharge (0.62 +/- 0.35 U/kg/day vs 0.85 +/- 0.29 U/kg/day, P less than 0.001), and higher mean plasma bicarbonate concentrations (19.3 +/- 3.9 mmol/l vs 15.8 +/- 5.9 mmol/l, P = 0.023) and mean plasma C-peptide levels (0.35 +/- 0.36 pmol/ml vs 0.14 +/- 0.15 pmol/ml, P less than 0.001). Further analyses on a subset of IDDM cases (n = 100) indicated that initial differences in metabolic indices observed at diagnosis were no longer apparent at one-year post-diagnosis. These results suggest that the etiology of familial and sporadic IDDM is similar and that the less severe presentation observed at diagnosis in the familial cases may be due to earlier identification of the disease, reflecting increased parental knowledge of diabetic symptoms and/or frequent testing for diabetes.

Age Factors↗
PubMed1991

Alterations in specific antibody production due to rank and social instability.

Separate studies examined the influence of the social environment of male cynomolgus macaques on primary and secondary antibody responses to immunization with tetanus toxoid. All animals showed evidence of both primary and secondary anti-tetanus antibody response. In the first study, subordinate animals had a greater primary antibody response to tetanus toxoid, while a single social reorganization (acute stressor) did not influence the response. In the second study, social rank was not associated with the secondary antibody response but repeated social reorganizations (chronic stressor) resulted in a greater level of specific antibody production in comparison to nonreorganized controls. These effects could not be accounted for on the basis of nonspecific differences in total serum IgG or serum albumin.

Animals↗
PubMed1991

Serum auto-antibodies in Alzheimer's disease.

The prevalence and clinical significance of non-CNS auto-antibodies in the serum of patients with probable and possible Alzheimer's disease (AD) was determined. Serum was obtained from 88 patients and 55 normal controls. Serum from each subject was tested for the presence of seven different auto-antibodies. Auto-antibodies were detected in 44% of the subjects with probable AD, 70% with possible AD with cerebrovascular disease (CVD), 45% with possible AD and other disease and 42% of normal controls. Although a subpopulation of AD patients with CVD showed a trend to an increased predisposition to develop autoimmune disease, these results do not support the relationship of AD and serum auto-antibodies or autoimmune disease.

Aged↗
PubMed1991

Long-term follow-up of children born to women immunized with tetanus toxoid during pregnancy.

Ten years after transplacental immunization with tetanus toxoid, the antibody responses of the immunized children to a booster immunization with 5 Lf tetanus toxoid did not differ from those of the control children. The tetanus toxoid-stimulated lymphocyte proliferative responses showed that there was no tolerance to tetanus toxoid induced by transplacental immunization, and the stimulation indices suggested that there may be some long-term memory for tetanus toxoid among the T lymphocytes in children who had been transplacentally immunized by maternal immunization with a standard dose of tetanus toxoid.

Antibodies, Bacterial↗
PubMed1990

T-lymphocyte reactivity during the menstrual cycle in women.

Reactivity of blood lymphocytes to nonspecific mitogenic stimulation with phytohemagglutinin (PHA) was measured in nine healthy, regularly cycling women at three phases of their menstrual cycles corresponding to peak levels of estradiol (midfollicular phase), peak levels of progesterone (midluteal phase), and the lowest levels of both hormones (menstrual phase). Sampling points were verified by radioimmunoassay of estrogen, progesterone, luteinizing hormone, and follicle-stimulating hormone. There were significant increases in reactivity associated with an increasing concentration of PHA and with autologous plasma vs AB plasma. However, no differences were found in reactivity to PHA over the three menstrual cycle phases and correlational analyses indicated no relationship between counts and any of the hormones measured.

Adolescent↗
PubMed1990

Evidence that shock-induced immune suppression is mediated by adrenal hormones and peripheral beta-adrenergic receptors.

Our previous work has demonstrated that presentations of mild foot-shock to Lewis rats induces a suppression of splenic and peripheral blood lymphocyte responses to nonspecific T-cell mitogens. The present study demonstrated that adrenalectomy prevented the shock-induced suppression of the mitogenic response of peripheral blood T-cells but did not attenuate the suppression of splenic T-cells. Conversely, the beta-adrenergic receptor antagonists, propranolol and nadolol, attenuated the shock-induced suppression of splenic T-cells in a dose-dependent manner but did not attenuate suppression of the blood mitogen response. These data indicate that distinct mechanisms mediate the shock-induced suppression of T-cell responsiveness to mitogens in the spleen and the peripheral blood. The results indicate that the peripheral release of catecholamines is responsible for splenic immune suppression and that adrenal hormones, which do not interact with beta-adrenergic receptors, are responsible for shock-induced suppression of blood mitogenic responses.

Adrenal Cortex Hormones↗
PubMed1990

Immobilization 12 days (but not one hour) earlier enhanced 2-deoxy-D-glucose-induced immunosuppression: evidence for stressor-induced time-dependent sensitization of the immune system.

1. Prior exposure to a stressor can either increase or decrease subsequent behavioral, neurochemical, and endocrine reactivity to stress, depending on the pattern of stress exposure. 2. Massed or frequent exposures typically induce a reduction in reactivity whereas intermittent or widely spaced exposures increase subsequent reactivity. 3. In the present study, the authors examined whether a single presentation of a temporally remote stressor would increase the immunosuppressive effects of a subsequent stressor. Specifically, the authors investigated the effectiveness of 2-deoxy-D-glucose (2-DG) in suppressing the responsiveness of splenic lymphocytes in male, Sprague-Dawley rats that received either no prior treatment, or immobilization either one hour or 12 days earlier. 4. Splenic lymphocyte responsiveness to the T-cell mitogens, Concanavalin A (Con-A) and phytohemagglutinin (PHA) was suppressed following a single injection of 2-DG. 5. The group exposed to the stress of immobilization one hour prior to 2-DG demonstrated a comparable level of immune suppression. 6. In contrast, animals immobilized 12 days prior to the administration of 2-DG showed a more pronounced suppression of immune responsiveness which was significantly greater than the other groups injected with 2-DG. 7. Neither the stress-induced elevation in corticosterone, nor the suppression of blood lymphocyte reactivity to Con-A and PHA was enhanced by prior immobilization. 8. The results indicate that the immunosuppressive effects of an acute stressor can sensitize with the passage of time.

Animals↗
PubMed1990

Evaluation of immunologic assays to determine the effects of differential housing on immune reactivity.

The mechanism is being investigated to determine specifically how an environmental variation such as differential housing can influence the multiple components of the host defense mechanism. Male C3H/HeJ mice were housed either one or five per cage. Cells and sera from these mice were analyzed and compared by several immunologic techniques to determine in which cells or tissues the effect of differential housing was most pronounced. The individually housed mice (a) had a greater capacity to phagocytose dead cells of Candida albicans. (b) had spleens that produced more macrophage colony stimulating factor (M-CSF). (c) were more responsive to M-CSF, (d) had peritoneal macrophages that released greater quantities of interleukin-1 in vitro into the surrounding medium and that had a greater capacity to migrate toward a chemotactic stimulus, and (e) had higher titers of IgM hemagglutination antibody to sheep erythrocytes. Differential housing of mice may therefore be a highly important modulator and indicator of the nature and extent of an animal's immunologic response to an environmental stimulus.

Animals↗
PubMed1990

Stressor-induced alteration of lymphocyte proliferation in mice: evidence for enhancement of mitogenic responsiveness.

The present study evaluated the immunomodulatory effect of the administration of different intensities of electric foot shock presentations to different strains of mice. The results showed an enhancement of the mitogenic responsiveness to concanavalin A (Con A), a T-lymphocyte mitogen, that was directly related to the intensity of the electric shock presentations. However, the electric shock induced no significant alteration of the mitogenic responsiveness to lipopolysaccharide (LPS), a B-lymphocyte mitogen. These findings were evident in HLA-SW/ICR, C57BL/6N, and C3H/HEJ mice. In contrast, the C3H/HEN mice did not show any alteration of mitogenic responsiveness. The number of splenic leukocytes was not altered by the electric shock presentations in the strains that showed enhanced mitogenic responsiveness, but the C3H/HEN strain showed a leukopenia directly related to the shock intensity. In a subsequent experiment, it was demonstrated that repeated sessions of electric shock resulted in a reduction in the enhancement effect. Collectively, the results demonstrate that stressful stimulation can result in an enhancement of mitogenic responsiveness, but that such an effect is dependent on the intensity and frequency of the stressor, as well as on the strain of the subject.

Animals↗
PubMed1989

Analyses on possible heterogeneity of IDDM based on presence of islet cell cytoplasmic antibody at diagnosis.

In a large, representative sample of newly-diagnosed IDDM patients, using a highly sensitive assay to detect islet cell cytoplasmic antibodies (ICA), no marked differences were found between ICA+ and ICA- patients on various clinical, genetic, immunologic, and epidemiologic characteristics. In particular, there was no evidence for associations between ICA status at diagnosis and either sex, race, family history of IDDM, HLA-DR phenotype, antibody titers to Coxsackie B viruses, immunoglobulin levels, C-peptide and glycosylated hemoglobin concentrations, or insulin requirements. The most significant relationship was between the presence of ICA and a young age at diagnosis; however, the large overlap between the distributions of the ages at onset for ICA+ and ICA- groups on this variable suggests that this association is of limited importance. These data suggest that the presence or absence of ICA at diagnosis may not be useful in defining possible subtypes of IDDM.

Adolescent↗
PubMed1989

Bidirectional interaction between the central nervous system and the immune system.

We believe that any questions regarding whether the CNS can alter immune system functions no longer remain. It can conclusively be stated that the immune system is susceptible to influences of the CNS. It remains to be determined whether all classes of lymphocytes, NK cells, macrophages, polymorphonuclear leukocytes, and other antigen-processing cells are all susceptible to CNS influences. We have presented evidence that peripheral blood lymphocytes may not reflect the immunological activity of lymphocytes within lymphatic tissue after being influenced by a stressor. Thus, all types of immunological cells must be evaluated in different organs. Whether the immune system of young and old animals respond in the same way must also be determined. The sex of the animal needs to be taken into consideration. What immune responses are important to measure? Do in vitro responses reflect the ability of an animal to resist infectious disease or susceptibility to autoimmune and malignant diseases? Certainly, absence of an immune response is detrimental to health. It must be determined whether moderately suppressed immune function in multiple compartments is as detrimental as total absence of an immune response in a single immunological compartment. The data that we have presented with respect to adjuvant arthritis indicate that an immune response in the peripheral of the animal can be modified by a stressor and influence an immunopathological process. This may indicate that the most important immune compartment to evaluate with respect to altering disease susceptibility is the peripheral blood and that lymphoid tissue may be interesting, but not clinically relevant. The reasons why the peripheral blood and lymphoid tissue differ in their immunological function following exposure to a stressor must be determined. We have reviewed information indicating that lymphoid tissue is innervated and that such innervation can modify immune function. In addition, hormones released by the CNS may alter immune function. Yet, much of this data are contradictory and whether immune enhancement or suppression occurs is not clearly defined with respect to any experimental manipulation involving denervation or the addition of hormones to in vitro cultures. Whether this reflects the age of the experimental animal, the type of immune response being measured, the adequacy of the experimental procedure, background rearing conditions of the animals, the amount of noise in the animal room, the diet of the animals, or the number of animals housed per cage all remain to be determined. Our purpose has not been to provide a comprehensive review of all of the data relating to the immune system/CNS interaction.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗