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Biomedical subjects

B S Rabin

Publications and source records attributed to B S Rabin.

At least 19 recordsLinked to original sources
PubMed2001

Characterization of the central nervous system innervation of the rat spleen using viral transneuronal tracing.

Splenic immune function is modulated by sympathetic innervation, which in turn is controlled by inputs from supraspinal regions. In the present study, the characterization of central circuits involved in the control of splenic function was accomplished by injecting pseudorabies virus (PRV), a retrograde transynaptic tracer, into the spleen and conducting a temporal analysis of the progression of the infection from 60 hours to 110 hours postinoculation. In addition, central noradrenergic cell groups involved in splenic innervation were characterized by dual immunohistochemical detection of dopamine-beta-hydroxylase and PRV. Infection in the CNS first appeared in the spinal cord. Splenic sympathetic preganglionic neurons, identified in rats injected with Fluoro-Gold i.p. prior to PRV inoculation of the spleen, were located in T(3)-T(12) bilaterally; numerous infected interneurons were also found in the thoracic spinal cord (T(1)-T(13)). Infected neurons in the brain were first observed in the A5 region, ventromedial medulla, rostral ventrolateral medulla, paraventricular hypothalamic nucleus, Barrington's nucleus, and caudal raphe. At intermediate survival times, the number of infected cells increased in previously infected areas, and infected neurons also appeared in lateral hypothalamus, A7 region, locus coeruleus, subcoeruleus region, nucleus of the solitary tract, and C3 cell group. At longer postinoculation intervals, infected neurons were found in additional hypothalamic areas, Edinger-Westphal nucleus, periaqueductal gray, pedunculopontine tegmental nucleus, caudal ventrolateral medulla, and area postrema. These results demonstrate that the sympathetic outflow to the spleen is controlled by a complex multisynaptic pathway that involves several brainstem and forebrain nuclei.

Animals↗
PubMed2001

Identification of delta- and mu-type opioid receptors on human and murine dendritic cells.

The purpose of this study was to evaluate mu- and delta-opioid receptors (OR) on human and murine dendritic cells (DC). Expression of mu- and delta-OR mRNA on DC was demonstrated by RT-PCR. The immunocytochemical and Western blot analyses revealed the expression of OR protein in DC. Radioreceptor assay demonstrated the specific saturated temperature-dependent binding of [3H]-labeled opioid ligand on DC and B(max)=2.8+/-0.3 fmol/10(6) cells and K(D)=4.8+/-1.0 nM were calculated by a Scatchard analysis. Finally, OR ligands DADLE and DAGO dose-dependently modulated the capacity of DC to induce T cell proliferation in an MLR assay. Importantly, expression of functional OR on DC was significantly increased upon TNF-alpha-induced DC maturation. Thus, these data suggest a new mechanism of opioid-dependent neuroendocrine immunomodulation.

Animals↗
PubMed2001

Associations between stress, trait negative affect, acute immune reactivity, and antibody response to hepatitis B injection in healthy young adults.

Eighty-four healthy graduate participants were administered the standard course of 3 hepatitis B vaccinations. Five months after the first dose (shortly after the second injection), each participant completed psychosocial measures, and a blood sample was drawn for determination of hepatitis B surface antibody titer. After completion of the vaccination series, participants performed an acute stress protocol, consisting of a 30-min adaptation period and a 5-min evaluative speech task. Blood was drawn at the end of the resting and task periods for assessment of cellular immune measures. Lower antibody response, as assessed after the second hepatitis B injection, was predicted independently by (a) high trait negative affect and (b) diminished T-cell proliferation in response to PHA. These data provide evidence that trait negative affect and the magnitude of stress-induced suppression of immune function may have clinical significance.

Adult↗
PubMed2000

The stability of and intercorrelations among cardiovascular, immune, endocrine, and psychological reactivity.

One hundred fifteen college students were exposed to an evaluative speech task twice, separated by 2 weeks. At both sessions, we assessed cardiovascular, endocrine, immune, and psychological response at baseline and during the task. We found stability across sessions for stress-induced increases in anxiety and task engagement, heart rate, blood pressure, norepinephrine (but not epinephrine), cortisol, natural killer cell cytotoxicity, and numbers of circulating CD3+, CD8+, and CD56+ (but not CD4+ or CD19+) lymphocytes. The stable cardiovascular, immune, and endocrine reactivities were intercorrelated, providing evidence of a unified physiological stress response across these outcomes. Although stable stress-induced increases in task engagement were associated with the physiological stress responses, stress-induced anxiety was not.

Adolescent↗
PubMed2000

Role of locus coeruleus in foot shock-evoked Fos expression in rat brain.

The robust activation of locus coeruleus neurons in response to a variety of stressors, in conjunction with the widespread outputs of the locus coeruleus, suggest that the locus coeruleus may be important in mediating responses to stress. Previous studies in rats have demonstrated that exposure to foot shock elicits Fos expression, a marker of neuronal activation, in the locus coeruleus and other brain sites. In order to evaluate the involvement of the locus coeruleus in foot shock-induced activation of other brain sites, shock-induced Fos expression was examined in the locus coeruleus and other brain areas known to be activated by foot shock, following direct inhibition of the locus coeruleus by local infusion of muscimol, a GABA agonist, prior to foot shock. Control rats received infusions of artificial cerebrospinal fluid into the locus coeruleus or muscimol into areas outside of locus coeruleus. Rats infused with artificial cerebrospinal fluid and then exposed to foot shock had significant increases in Fos expression in several brain areas, including locus coeruleus, nucleus O, several subdivisions of the hypothalamus, subnuclei of amygdala, bed nucleus of the stria terminalis and cingulate cortex. Inhibition of the locus coeruleus prior to foot shock significantly inhibited Fos expression in the locus coeruleus, nucleus O, some subdivisions of the hypothalamus including the magnocellular and medial parvicellular paraventricular hypothalamic nucleus, subnuclei of amygdala, and cingulate cortex. In contrast, inhibition of the locus coeruleus did not affect shock-induced Fos expression in other areas, including certain subdivisions of the hypothalamus and bed nucleus of the stria terminalis. We suggest that foot shock may activate multiple pathways, with activation of certain discrete nuclei requiring input from the locus coeruleus and activation of others occurring independently of locus coeruleus input.

Animals↗
PubMed1999

Personality and tonic cardiovascular, neuroendocrine, and immune parameters.

Although there is now abundant evidence that certain personality features constitute risk factors for negative health outcomes, personality measures have received little attention to date in the behavioral immunology literature. The present study assessed the relationship between major dimensions of personality and tonic cardiovascular, neuroendocrine, and immunologic parameters in 276 healthy adults. Participants who scored low in agreeableness tended to have higher levels of systolic blood pressure, diastolic blood pressure, and epinephrine. Low levels of extraversion were associated with higher blood pressure, epinephrine, norepinephrine, and natural killer cell cytotoxicity. Neuroticism was generally unrelated to physiologic outcomes. Personality was not associated with leukocyte subset counts. The magnitude of relationships between personality and physiology was modest, with personality measures accounting for 1 to 7% of the variance in selected physiological parameters. Health practices did not mediate associations between personality and physiologic outcomes. However, a substantial proportion of the relationship between extraversion and natural killer cell cytotoxicity was accounted for by their common association with epinephrine and to a lesser extent norepinephrine. These findings are consistent with the notion that personality contributes to basal physiology and provide a foundation for further research on the relationship between personality and natural killer cell cytotoxicity.

Adolescent↗
PubMed1999

Relation between aerobic fitness level and stress induced alterations in neuroendocrine and immune function.

Alterations in neuroendocrine and immune function were examined in sedentary (n=15) (VO2peak; 31.4+/-0.7 ml x kg(-1) x min(-1); 24.4+/-1.2yr), moderately active (n=15) (VO2peak; 45.4+/-1.1 ml x kg(-1) x min(-1); 24.2+/-1.1 yr) and aerobically trained (n=15) (VO2peak; 58.8+/-0.9 ml x kg(-1) x min(-1); 24.3+/-1.0 yr) men following exposure to an acute mild psychological stressor. Subjects had 2 min to prepare, and 3 min to deliver a speech in front of 3 observers. Blood samples were drawn from an indwelling catheter before, during and 30 min following the speech task (ST). Self-reported measures of anxiety were obtained prior to and immediately following the stressor. The ST resulted in significant alterations in the number and function of immune cells, and in self-reported anxiety scores. Plasma levels of norepinephrine increased during the speech task. The neuroendocrine and immune response to the chosen stressor were independent of subject aerobic fitness level.

Exercise↗
PubMed1998

Injection of corticotropin-releasing hormone into the locus coeruleus or foot shock increases neuronal Fos expression.

Previous research suggests that corticotropin-releasing hormone can act in the locus coeruleus to increase the firing of locus coeruleus neurons and elicit physiological responses resembling those associated with stress. The present study used immunocytochemical detection of Fos as a measure of neuronal activation to identify brain areas that were activated by bilateral injections of corticotropin-releasing hormone into the locus coeruleus of rats. Injection of corticotropin-releasing hormone into the locus coeruleus increased the expression of Fos in the locus coeruleus as compared with injection of vehicle into the locus coeruleus or injection of corticotropin-releasing hormone into neighbouring pontine sites. The pattern of Fos expression throughout the brain after injections of corticotropin-releasing hormone into the locus coeruleus was generally consistent with the anatomical organization of efferent projections arising from the locus coeruleus; increased Fos expression was observed in many brain areas including the ventral lateral septum, septohypothalamic nucleus, bed nucleus of the stria terminalis, the central amygdaloid nucleus, the dorsomedial nuclei of the hypothalamus, and the thalamic paraventricular and rhomboid nuclei. Foot shock also increased Fos expression in the locus coeruleus and the other brain regions that expressed Fos after corticotropin-releasing hormone injections into the locus coeruleus. A few brain regions, most notably the hypothalamic paraventricular nucleus, expressed Fos in response to foot shock but not corticotropin-releasing hormone. These results indicate that local injection of corticotropin-releasing hormone into the locus coeruleus stimulates the activity of the locus coeruleus neurons. However, the pattern of Fos expression throughout the brain evoked by injection of corticotropin-releasing hormone into the locus coeruleus does not fully replicate the effects of foot shock.

Animals↗
PubMed1998

Types of stressors that increase susceptibility to the common cold in healthy adults.

Two-hundred seventy-six volunteers completed a life stressor interview and psychological questionnaires and provided blood and urine samples. They were then inoculated with common cold viruses and monitored for the onset of disease. Although severe acute stressful life events (less than 1 month long) were not associated with developing colds, severe chronic stressors (1 month or longer) were associated with a substantial increase in risk of disease. This relation was attributable primarily to under- or unemployment and to enduring interpersonal difficulties with family or friends. The association between chronic stressors and susceptibility to colds could not be fully explained by differences among stressed and nonstressed persons in social network characteristics, personality, health practices, or prechallenge endocrine or immune measures.

Adolescent↗
PubMed1997

Social ties and susceptibility to the common cold.

OBJECTIVE: To examine the hypothesis that diverse ties to friends, family, work, and community are associated with increased host resistance to infection. DESIGN: After reporting the extent of participation in 12 types of social ties (eg, spouse, parent, friend, workmate, member of social group), subjects were given nasal drops containing 1 of 2 rhinoviruses and monitored for the development of a common cold. SETTING: Quarantine. PARTICIPANTS: A total of 276 healthy volunteers, aged 18 to 55 years, neither seropositive for human immunodeficiency virus nor pregnant. OUTCOME MEASURES: Colds (illness in the presence of a verified infection), mucus production, mucociliary clearance function, and amount of viral replication. RESULTS: In response to both viruses, those with more types of social ties were less susceptible to common colds, produced less mucus, were more effective in ciliary clearance of their nasal passages, and shed less virus. These relationships were unaltered by statistical controls for prechallenge virus-specific antibody, virus type, age, sex, season, body mass index, education, and race. Susceptibility to colds decreased in a dose-response manner with increased diversity of the social network. There was an adjusted relative risk of 4.2 comparing persons with fewest (1 to 3) to those with most (6 or more) types of social ties. Although smoking, poor sleep quality, alcohol abstinence, low dietary intake of vitamin C, elevated catecholamine levels, and being introverted were all associated with greater susceptibility to colds, they could only partially account for the relation between social network diversity and incidence of colds. CONCLUSIONS: More diverse social networks were associated with greater resistance to upper respiratory illness.

Adolescent↗
PubMed1997

Immune system differences in men with hypo- or hypercholesterolemia.

Substantial epidemiologic evidence indicates that relative hypocholesterolemia in apparently healthy individuals is associated with increased subsequent mortality from cancer and other nonatherosclerotic causes of death. To test a hypothesis potentially underlying these unexplained associations, we evaluated whether individuals with hypo- and hypercholesterolemia differ in various enumerative and functional indices of the immune system. Nineteen healthy adult men with a mean age of 46 years and a mean total cholesterol concentration of 151 mg/dl constituted a low cholesterol group and were compared with 39 men of a similar age whose total cholesterol averaged 261 mg/dl. Relative to the high cholesterol group, hypocholesterolemic men had significantly fewer circulating lymphocytes, fewer total T cells, and fewer CD8+ cells (P's < 0.05). Trends toward fewer CD4+ cells and less IL-2 release in response to PHA were also noted in the low, compared to the high, cholesterol group. The low and high cholesterol groups did not differ in number of B lymphocytes, level of PHA-induced proliferation, number of natural killer (NK) cells, or degree of NK cytotoxicity. These data provide preliminary evidence of immune system differences in healthy individuals with hypo- and hypercholesterolemia.

Adult↗
PubMed1997

Lactation alters the effects of conditioned stress on immune function.

During lactation, endocrine function is altered and stress responses are dampened. Stress effects on immune function are partially determined by endocrine factors; therefore, we assessed whether stress similarly alters immune function during lactation. Sprague-Dawley rats were conditioned by exposure to a tone paired with foot shock (2 sessions, 16 shocks each) prior to breeding or were left undisturbed. Lactating (day 10) (Lac) and nonlactating diestrous virgin controls (C) were killed immediately after reexposure to the tone or removal from their home cage. Plasma corticosterone stress responses were dampened in Lac relative to C animals. Peripheral blood lymphocyte proliferation to T cell receptor antibody stimulation was reduced to a similar extent in both experimental groups. Conditioned stress reduced splenocyte proliferation and increased nitrite accumulation in C animals, but not in Lac animals. Mesenteric lymph node lymphocyte proliferation was significantly increased after stress in Lac compared with C animals. Both plasma interleukin-6 (IL-6) and phytohemagglutinin-stimulated splenic IL-6 production were increased in Lac animals compared with C animals after stress exposure. These data indicate that stress-induced alterations may be determined by different regulatory mechanisms within immune compartments and that these effects depend on the physiological state of the organism.

Animals↗
PubMed1996

The effects of incremental submaximal exercise on circulating leukocytes in physically active and sedentary males and females.

To study the effects of exercise on circulating leukocytes and leukocyte subsets, physically active (n = 32) and sedentary (n = 32) male and female subjects were randomly assigned to an exercise or control condition. Exercise involved a continuous incremental protocol consisting of cycling for three periods of 6 min at power outputs corresponding to 55%, 70% and 85% maximal oxygen uptake (VO2max). Blood samples were drawn from a venous catheter at baseline, and at 6 min, 12 min, and 18 min after beginning the exercise and 2 h following completion of exercise. Resting- and exercise-induced alterations in total leukocytes were independent of gender and subject fitness level. Relative to baseline, each increment in workload resulted in a rapid increase in the number of circulating leukocytes. Increases in neutrophils, lymphocytes and monocytes accounted for the exercise-induced leukocytosis. With regard to lymphocytes, exercise resulted in a significant increase in the number of T cells (CD3+), T helper cells (CD4+), T suppresser (CD8+) and natural killer (NK) cells (CD3-/CD16+/CD56+). The largest percentage increase occurred in the NK cell population. The CD4+: CD8+ ratio decreased (P < 0.001) throughout exercise due to a larger increase in the number of CD8+ cells relative to CD4+ cells. An exercise-induced neutrophilia, lymphocytopenia, and eosinophelia was observed 2 h into recovery. Exercise resulted in significant increases in plasma epinephrine and norepinephrine levels. There was no indication of a hypothalamic-pituitarty-adrenal response during exercise. The results indicate that the rapid, albeit transient, alteration in the number of circulating leukocytes during and following an acute progressive incremental exercise test are independent of gender and fitness.

Adult↗
PubMed1996

Exercise-induced alterations in natural killer cell number and function.

To study the effects of exercise on natural killer (NK) cell number and activity (NKCA) healthy male (n = 32) and female (n = 32) subjects were randomly assigned to an exercise or control condition. Exercise involved a continuous incremental protocol consisting of cycling for three periods of 6 min at work rates corresponding to 55%, 70% and 85% peak oxygen uptake (VO2peak). Blood samples were drawn at baseline, at 6 min, 12 min and 18 min during exercise, and at 2 h following completion of exercise. Relative to both baseline and control conditions, exercise resulted in an increase in the number of circulating lymphocytes. The proportion of T cells (CD3+) and B cells (CD19+) significantly decreased, and NK cells (CD3-CD16+CD56+) increased throughout exercise. NKCA increased (P < 0.001) during the initial 6 min of exercise with no further changes observed, despite increases (P < 0.001) in the number and proportion of circulating NK cells during exercise at 70% and 85% VO2peak. Plasma epinephrine and norepinephrine increased (P < 0.001) above baseline at 12 min and 18 min. The changes in NK cell number and function were independent of gender. The results indicate that short-duration low-intensity exercise can significantly increase NK cell number and activity. However, alterations in NK cell number are not accompanied by changes of a similar magnitude in NKCA.

Adult↗
PubMed1996

Immunologic response to acute psychological stress in MS patients and controls.

To determine whether MS patients differ from healthy subjects in stress-related immune changes, we examined immunologic alterations following a public speaking task in 25 MS patients and 25 healthy controls. Both groups demonstrated similar autonomic, neuroendocrine and immunologic responses to acute stress. Neutrophils, monocytes, CD8+ suppressor/cytotoxic T-lymphocytes and NK-cells transiently increased, with parallel changes in NK-cell activity. T-cell proliferation declined at 20 min, followed by increased reactivity at 60 min relative to baseline. This data suggests that stress-induced immune alterations remain intact in MS patients, and may contribute to immune changes associated with disease exacerbation.

Acute Disease↗