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Biomedical subjects

M Irwin

Publications and source records attributed to M Irwin.

At least 73 records · Page 4Linked to original sources
PubMed1994

Immunity and depression: insomnia, retardation, and reduction of natural killer cell activity.

Depressed patients show a reduction of natural killer (NK) cell activity which may be associated with specific depressive symptoms. The present study demonstrated that sleep disturbance and retardation, but not other depressive symptoms, were negatively correlated with NK activity in 38 depressed patients. Specific behavioral changes in depression such as sleep disturbance and retardation were found to predict 16% of the variance of cytotoxicity levels in depression.

Adult↗
PubMed1994

Bereavement, depression, and immune function.

This study evaluates whether recently widowed women who fulfill criteria for a depressive syndrome differ in their immune responses from widows who do not. Twenty-one middle-aged widows who had lost their spouses 2 months before the initial evaluation and 21 demographically matched married women were evaluated at approximately 6-month intervals for 13 months. Evaluations consisted of diagnostic interviews using the Schedule for Affective Disorders and Schizophrenia, Hamilton Rating Scale for Depression, and Beck Depression Inventory. Immune function was measured by total lymphocyte counts, natural killer (NK) cell activity, mitogen responsiveness to concanavalin A, and T-cell subsets. There were no statistically significant differences on any of the immune measures between the entire cohort of widows and control subjects. However, the subset of widows who met DSM-III-R criteria for major depressive syndromes demonstrated impaired immune function (lower NK cell activity and lower mitogen stimulation) compared with those who did not meet criteria for major depression. This study suggests a relationship between impaired immune function and depression in women experiencing the stress of bereavement.

Aged↗
PubMed1994

One-year incidence rate of major depression and other psychiatric disorders in 239 alcoholic men.

The rate of depressive symptoms among alcoholics is high, but many of these syndromes appear to be alcohol-induced mood disorders and might not represent major depressive episodes independent of heavy drinking. The present study examines one aspect of the relationship between alcoholism and depression by evaluating the incidence of new episodes of major depressive disorders among alcohol-dependent men during the year following treatment. One year following discharge from an alcohol treatment program, structured face-to-face interviews were carried out with 239 primary alcoholic men, as well as additional informants. Approximately 4% of the men developed depressive episodes while drinking heavily, but only 2.1% demonstrated major depressions independent of heavy alcohol intake. There was no evidence of an increased incidence of any other major psychiatric disorder during the year of follow-up. These results are consistent with prospective studies of children of alcoholics and of longitudinal evaluations of general population samples. They do not indicate that in the present sample most primary alcohol-dependent men have elevated rates for major depressive disorders independent of alcohol-induced mood syndromes. However, it is likely that in the context of heavy drinking severe, although temporary, depressive episodes are likely to be observed.

Adult↗
PubMed1994

DDI pacing: indications, expectations, and follow-up.

The DDI mode of pacing that permits noncompetitive atrioventricular sequential bradycardia support was chosen in 65 of 480 (14%) patients selected for dual chamber pacing between February 1985 and March 1990. All patients were implanted with Pacesetter 283 or 285 pulse generators and programmed to DDI. The indications for pacing were sick sinus syndrome (n = 52), combined sinus node dysfunction and AV block (n = 13). Forty-two of these patients had a history of paroxysmal atrial arrhythmias. All patients received passive fixation atrial and ventricular leads. Follow-up thereafter was performed predischarge, and at 6 weeks, 3 and 6 months after discharge. The duration of follow-up ranged from 1-61 months (mean 31 months). Fifty-four of 65 (83%) patients chosen for DDI remain programmed in the DDI mode. Three patients were reprogrammed to VVI and eight to DDD. During the course of follow-up, six patients presented with effective VVI pacing with consistent ventriculoatrial conduction that was appropriately sensed by the atrial circuit with atrial output inhibition. A further four patients presented with "functional undersensing" due to ventricular blanking period (VBP) characteristics in these pulse generators and in this mode. Functional undersensing was eliminated in all but one patient by reprogramming the VBP to 13 msec with no subsequent episodes of provoked crosstalk inhibition. Effective VVI pacing was observed in patients with AV block during times of sinus acceleration.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Sustained attention and grade retention.

Two studies are reported which explore the possible relationship between academic failure, as measured by grade retention, and the capacity to sustain attention on a computerized continuous performance task. In a nonreferred sample, 89 children who had been retained at some point in their academic careers showed a higher frequency of abnormal scores on an index of sustained attention than did 93 children who had never repeated a grade. In a sample of children who had been referred for an evaluation of Attention-Deficit Hyperactivity Disorder, children with a history of grade retention had significantly lower scores on the same measure of sustained attention. Results are discussed in terms of the possible contribution of attention deficits to over-all academic achievement, even for children who have not necessarily been referred for a clinical evaluation.

Attention↗
PubMed1993

Benzodiazepines antagonize central corticotropin releasing hormone-induced suppression of natural killer cell activity.

Benzodiazepines have anxiolytic properties and attenuate behavioral stress responses induced by corticotropin releasing hormone (CRH). To evaluate the effect of benzodiazepines on CRH-induced immune suppression, potent centrally acting benzodiazepines were administered prior to central infusion of CRH (i.c.v.; 1.0 microgram). CRH induced a significant (P < 0.01) reduction of splenic natural killer cell activity which was completely antagonized by pretreatment with either diazepam or alprazolam.

Alprazolam↗
PubMed1993

Stress-induced immune suppression. Role of the autonomic nervous system.

Experimental data together with clinical studies have generated information about the association between sympathetic nervous system activity and immunity as measured by in vitro correlates of cellular immune function. In addition, studies on the in vivo role of central CRF in coordinating sympathetic outflow and modulating immune function have provided an opportunity to examine central mechanisms important in the link between brain, behavior, and immune function. Finally, use of CRF as a neuropeptide probe will likely continue to give information about the central mechanisms relevant to the abnormal regulation of sympathetic nervous activity and immune function in stress and possibly in aging.

Aging↗
PubMed1993

Sympathetic regulation of T-helper cell function.

The role of sympathetic neurotransmission in regulation of T-cell function was examined in mice. After in vivo priming with a model protein antigen, hen egg white lysozyme (HEL), the specific proliferative recall response of lymph node cells (LNCs) was examined. The release of endogenous catecholamines by amphetamine (5 mg/kg, 45 min prior to sacrifice) markedly inhibited the proliferative response of LNCs. Combined alpha- and beta-adrenergic blockade (phentolamine, 1.0 mg/kg+propranolol, 2.5 mg/kg) prevented this effect of amphetamine on proliferation. In vitro, the alpha-adrenergic agonist phenylephrine, but not the beta-agonist isoproterenol, inhibited proliferation in a dose-dependent manner, up to 80%. The effect of phenylephrine was blocked by the alpha-adrenoceptor antagonist phentolamine. The effects of catecholamines appear to be mediated at the level of antigen processing/presentation: Amphetamine given prior to sacrifice inhibited interleukin 2 production when irradiated spleen cells were used to present HEL and HEL-related peptides to HEL-specific T-cell hybridomas. In summary, the sympathetic nervous system seems to inhibit antigen processing/presentation and, indirectly, T-helper responses.

Animals↗
PubMed1993

A comparison of sleep EEGs in patients with primary major depression and major depression secondary to alcoholism.

Polygraphic sleep recordings were compared between patients with primary major depression (MDD), patients with primary alcoholism and secondary MDD, and normals. Patients differed significantly from normals on the following measures: both patient groups showed short REM latency, and REM latency corrected, along with prolonged sleep latency. Secondary depressives differed from controls on several other measures: sleep onset time, total sleep time, delta sleep, REM percent, stage one sleep, stage three sleep, non-REM sleep, stage three and delta sleep in the first non-REM period. Prior research has shown a decrease in non-REM sleep and total sleep time in alcoholic patients who are not currently depressed, and short REM latency in patients with MDD. Thus, our findings suggest an additive effect of two disorders known to affect sleep: alcoholism and depression.

Adult↗
PubMed1993

Capsular tissues of the proximal interphalangeal joint: normal composition and effects of Dupuytren's disease and rheumatoid arthritis.

Three fibrocartilages associated with the proximal interphalangeal joint are described--at the attachment of the central slip to bone, within the slip where it passes over the joint, and the volar plate. Material was obtained at surgery following trauma, Dupuytren's disease and rheumatoid arthritis. The fibrocartilages were structurally distinct and immunolabelled differently with monoclonal antibodies to extracellular matrix components. All fibrocartilages from normal and Dupuytren's fingers contained chondroitin and keratan sulphate. Type II collagen was present in all attachment zones, although there was little in rheumatoid fingers. It was also present in the dorsal hood of some normal fingers, but not in pathological specimens or the volar plate. The results show that the fibrocartilages are dynamic tissues whose composition varies according to function and use, and changes in disease.

Adult↗
PubMed1993

Subjective predictions of outcome among alcoholics.

This study examines the importance of Subjective Staff Ratings as predictors of the 3- and 12- month outcomes in 375 male primary alcoholic inpatients. For short-term outcome, while combinations of more usual predictors including two aspects of the pretreatment drinking history, evidence of a stable personal relationship, prior alcoholic hospitalizations, employment status, and posttreatment recovery home placement explained up to 5% of the variance on three measures of short-term outcome, Subjective Ratings alone explained up to 6%. The combination of Subjective Ratings and objective historical data explained up to 9% of the variance. The data indicate that it is difficult to accurately predict short term outcome among primary alcoholics, that the Subjective Ratings of prognosis by the treatment staff are important predictors of short-term outcome which do not overlap greatly with more traditional predictors, but that these ratings appear to add little to the longer term outcome prediction.

Adult↗
PubMed1993

Clinical course of alcoholism in 636 male inpatients.

OBJECTIVE: This study was undertaken to determine the relative order of appearance of symptoms in alcohol dependence. METHOD: The age at which 21 alcohol-related major life events first occurred was investigated in 636 male alcohol-dependent inpatients through a standardized, structured personal interview with each subject and at least one resource person. RESULTS: A general pattern of first occurrence of these events was observed. Heavy drinking escalated further when the subjects were in their late 20s, followed by evidence of interference with functioning in multiple life areas in the early 30s, a subsequent perception of loss of control, and then an intensification of social and job-related problems, along with evidence of deterioration in body systems, in the mid- to late 30s. Similar patterns of problems emerged when the alcoholic subjects were divided into subgroups based on onset of alcohol dependence before or after age 30, presence or absence of a family history of alcoholism, and presence or absence of additional psychiatric disorders. CONCLUSIONS: These data indicate that there is a typical progression of events related to alcohol dependence. This information can be useful for clinicians in their work with patients and for teachers and researchers as well.

Adult↗
PubMed1993

Brain corticotropin-releasing hormone- and interleukin-1 beta-induced suppression of specific antibody production.

CRH serves as a central nervous system mediator of autonomic and visceral responses to stress. In addition, central infusion of CRH has a role in the modulation of in vitro correlates of cell-mediated immune function, such as natural killer cell activity and T-lymphocyte proliferation. The present study examined the effects of central CRH on an integrated in vivo immune response, specific antibody production to a novel antigen. Synthetic rat CRH (1.0 micrograms) microinjected into the lateral ventricle significantly (P < 0.001) slowed the induction of a specific immunoglobulin G (IgG) antibody response to the T-cell-dependent antigen keyhole limpet hemocyanin (KLH) after either primary or secondary immunization. CRH-induced suppression of the IgG response in vivo was found after immunization with a low threshold dose of KLH, but not when a 100-fold increased dose of antigen was given. Administration of CRH 20 min before immunization reduced the antibody response, whereas CRH infusion 24 h after KLH exposure failed to alter antibody levels, suggesting that CRH alters initial antigen processing. These effects of CRH on an in vivo antibody response were due to the infusion of CRH into the brain, as a 1.0-micrograms dose of CRH injected either ip or sc had no effect. In addition, central coadministration of the CRH antagonist alpha-helical CRH-(9-41) significantly blocked the immunosuppressive action of CRH. Finally, as central interleukin-1 beta has been reported to modulate cellular immunity, we examined the effect of central infusion of interleukin-1 beta on the KLH antibody response and found that intracerebroventricular interleukin-1 beta (50 ng) produced a significant (P < 0.001) suppression of the IgG response to KLH. These findings extend previous data on central CRH-induced suppression of in vitro measures of cellular immunity and demonstrate that CRH acts in the brain to reduce an in vivo antibody response.

Animals↗
PubMed1992

Lack of association between an RFLP near the D2 dopamine receptor gene and severe alcoholism.

Blum et al (1990) have recently examined a restriction fragment length polymorphism (RFLP) detected by TaqI RFLP to the dopamine D2 receptor gene (DRD2) in deceased alcoholics and nonalcoholics, and reported an association between alcoholism and the A1 allele. Subsequent studies, however, by other investigators have failed to confirm this. We have examined the DRD2 TaqI RFLP in 47 living Caucasian males with severe alcoholism. All alcoholic subjects were thoroughly characterized by a structured interview, and met DSM-III-R criteria for alcohol dependence. Only 9/47 (19%) (1990) of these alcoholics had the AI allele compared to 14/22 (64%) reported by Blum et al. This rate was not significantly different from the rates reported in control populations by Blum et al (1990), CEPH, or Bolos et al (1990), and differed only slightly from those reported by Grandy et al (1990). Alcoholics selected for severe medical complications also displayed a similar rate. Our data do not support an association between alcoholism and the D2 dopamine receptor gene in this population.

Adult↗
PubMed1992

Central corticotropin-releasing hormone reduces cellular immunity.

Corticotropin-releasing hormone (CRH) acts within the brain to elicit changes in neuroendocrine, autonomic, and behavioral activity similar to those observed after stress. A reduction of splenic natural killer (NK) activity has also been described following the central administration of CRH. In this study, we examined whether other in vitro measures of cellular immunity, including peripheral and splenic NK activity, lymphocyte responses to mitogen stimulation, and numbers of splenic T and NK cell subpopulations, are altered following CRH. Synthetic rat CRH (1.0 microgram) microinjected into the lateral ventricle reduced splenic and peripheral blood NK activity, lymphocyte responses to mitogenic stimulation, and percentage of splenic NK cell numbers. Numbers of splenic lymphocytes and T cell subpopulations were not altered by central CRH. These findings suggest that central CRH acts to reduce a number of in vitro cellular immune measures similar to the effects of inescapable stress.

Animals↗
PubMed1992

Depression and reduced natural killer cytotoxicity: a longitudinal study of depressed patients and control subjects.

Cross-sectional studies have demonstrated that natural killer (NK) cell activity is reduced in depression. To extend these observations and examine further the association between severity of depressive symptoms and values of NK activity, this study used a longitudinal case-control design and assessed NK cytotoxicity at intake and at follow-up 6 months after discharge from the hospital in depressed patients and control subjects. From acute hospitalization to follow-up, depression scores significantly (P < 0.01) decreased following treatment in the depressed patients but did not change in the control subjects. NK activity significantly (P < 0.05) increased from intake to follow-up in the depressives while lytic activity did not change in the controls. At intake NK activity was significantly (P < 0.01) reduced in the depressed patients as compared to values in the controls, while at follow-up cytotoxicity was similar between the two groups. These longitudinal data suggest that a reduction of NK cytotoxicity is temporally associated with the state of acute depression.

Adult↗