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Sensitivity of whole-blood T lymphocytes in individual patients to tacrolimus (FK 506): impact of interleukin-2 mRNA expression as surrogate measure of immunosuppressive effect.

BACKGROUND: To optimize immunosuppressive treatment in individual transplant patients, functional measurements of the effects of tacrolimus (FK 506) are of clinical importance. Previous investigations have demonstrated the occurrence of tacrolimus-resistant production of interleukin-2 (IL-2) in vitro, which may explain in part why rejection episodes are still a frequent problem despite attainment of therapeutic blood concentrations and HLA matching. However, an adequate surrogate marker to define the tacrolimus response in individual patients has not been established. METHODS: We investigated the immunosuppressive effects of tacrolimus on anti-CD3/anti-CD28 T-cell costimulation in a human whole-blood assay, analyzing T-cell proliferation, activation marker expression (CD25, CD69), IL-2 protein expression, and cytokine mRNA expression in vitro (n = 11 healthy individuals). We also quantified IL-2 mRNA expression in patients undergoing tacrolimus (n = 4) or cyclosporin A (CsA; n = 4) monotherapy before ex vivo living-donor kidney transplantation. RESULTS: T-cell proliferation; CD25, CD69, and IL-2 concentrations; and IL-4 mRNA were significantly decreased in vitro. In contrast, cytokine mRNA profiles revealed variable tacrolimus sensitivity. Whole-blood samples from 3 of 11 healthy individuals demonstrated marked suppression of IL-2 mRNA expression (>50%) when tacrolimus was administered in vitro. When CsA was added to whole-blood cultures, the influence on IL-2 mRNA expression was comparable to that of tacrolimus in 9 of 11 individuals. Two individuals responded conversely, indicating that differences in the in vitro response to tacrolimus and CsA among individuals may be attributable to potential heterogeneity in the involvement of the CD28 pathway. Kinetic profiles of IL-2 mRNA expression also revealed individually distinct degrees of calcineurin inhibitor sensitivity in patients undergoing tacrolimus or CsA monotherapy before living-donor kidney transplantation. CONCLUSIONS: Our results suggest an individual degree of calcineurin inhibitor sensitivity of activated whole-blood lymphocytes based on IL-2 mRNA expression. Our approach is potentially valuable for identifying transplant patients in whom IL-2 mRNA expression is unaffected or even enhanced after initiation of immunosuppressive therapy. Such individuals may be less sensitive to the immunosuppressive agent and therefore at increased risk of transplant rejection. Prospective studies are necessary to determine the correlation of IL-2 mRNA expression with the clinical risk of transplant rejection.

Adult↗

Pulmonary function in individuals with a history of poliomyelitis.

We examined the relationship between the lung function of 74 individuals with a history of poliomyelitis and reports of shortness of breath during activities of daily living, and the presence of post-polio sequelae risk factors. First, we studied the spirometry of 60 individuals (group 1) and second, we studied the relationship between the spirometry of an additional 14 individuals (group 2) and their respiratory muscle strength (Pimax and Pemax). In both groups, we examined the relationship between factors associated with post-polio sequelae including ventilation at polio-onset, having contracted polio after the age of 10, and having had polio for over 35 years; and lung function. In group 1, the FEV1 and FVC were lower for individuals with shortness of breath than individuals without (p less than 0.01). With respect to risk factors, FEV1 and FVC were lower in individuals who were ventilated at polio-onset, in individuals who contracted polio over 10 years of age, and in individuals who had had polio for less, rather than more than 35 years (p less than 0.05). The results for group 2 were comparable to group 1. In addition, the observed Pimax and Pemax were significantly lower than predicted values (p less than 0.05). Although FEV1 and FVC were positively correlated with both Pimax and Pemax (p less than 0.05), Pemax was disproportionately impaired compared to Pimax (40 +/- 12.1 and 82 +/- 38.8 percent predicted respectively). We conclude that individuals with a history of poliomyelitis can have compromised lung function irrespective of shortness of breath, that risk factors such as ventilation at polio-onset and polio-onset after 10 years of age can help predict those at risk of respiratory compromise, and that the measurement of respiratory muscle strength and of Pemax in particular, can augment the assessment of lung function of these individuals. Such assessment may avert respiratory complications in the post poliomyelitis population including those secondary to health care interventions.

Adult↗

The ecological effects of individual exposures and nonlinear disease dynamics in populations.

To describe causally predictive relationships, model parameters and the data used to estimate them must correspond to the social context of causal actions. Causes may act directly upon the individual, during a contact between individuals, or upon a group dynamic. Assuming that outcomes in different individuals are independent puts the causal action directly upon individuals. Analyses making this assumption are thus inappropriate for infectious diseases, for which risk factors alter the outcome of contacts between individuals. Transmission during contact generates nonlinear infection dynamics. These dynamics can so attenuate exposure-infection relationships at the individual level that even risk factors causing the vast majority of infections can be missed by individual-level analyses. On the other hand, these dynamics amplify causal associations between exposure and infection at the ecological level. The amplification and attenuation derive from chains of transmission initiated by exposed individuals but involving unexposed individuals. A study of household exposure to the only vector of dengue in Mexico illustrates the phenomenon. An individual-level analysis demonstrated almost no association between exposure and infection. Ecological analysis, in contrast, demonstrated a strong association. Transmission models that are devoid of any sources of the ecological fallacy are used to illustrate how nonlinear dynamics generate such results.

Dengue↗

Population-based incidence rates and risk factors for type 2 diabetes in white individuals: the Bruneck study.

Incidence rates and risk factors for type 2 diabetes in low-risk populations are not well documented. We investigated these in white individuals who were aged 40-79 years and from the population of Bruneck, Italy. Of an age- and sex-stratified random sample of 1,000 individuals who were identified in 1990, 919 underwent an oral glucose tolerance test (OGTT) and an assessment of physiological risk factors for diabetes, including insulin resistance (homeostasis model assessment, HOMA-IR), and postchallenge insulin response (Sluiter's Index). Diabetes at baseline by fasting or 2-h OGTT plasma glucose (World Health Organization criteria, n = 82) was excluded, leaving 837 individuals who were followed for 10 years. Incident cases of diabetes were ascertained by confirmed diabetes treatment or a fasting glucose >or=7.0 mmol/l. At follow-up, 64 individuals had developed diabetes, corresponding to a population-standardized incidence rate of 7.6 per 1,000 person-years. Sex- and age-adjusted incidence rates were elevated 11-fold in individuals with impaired fasting glucose at baseline, 4-fold in those with impaired glucose tolerance, 3-fold in overweight individuals, 10-fold in obese individuals, and approximately 2-fold in individuals with dyslipidemia or hypertension. Incidence rates increased with increasing HOMA-IR and decreasing Sluiter's Index. As compared with normal insulin sensitivity and normal insulin response, individuals with low insulin sensitivity and low insulin response had a sevenfold higher risk of diabetes. Baseline impaired fasting glucose, BMI, HOMA-IR, and Sluiter's Index were the only independent predictors of incident diabetes in multivariate analyses. We conclude that approximately 1% of European white individuals aged 40-79 years develop type 2 diabetes annually and that "subdiabetic" hyperglycemia, obesity, insulin resistance, and impaired insulin response to glucose are independent predictors of diabetes.

Adult↗

Geographic variation of lower-extremity major amputation in individuals with and without diabetes in the Medicare population.

OBJECTIVE: To describe geographic variation in rates of lower-limb major amputation in Medicare patients with and without diabetes. RESEARCH DESIGN AND METHODS: This cross-sectional population-based study used national fee-for-service Medicare claims from 1996 through 1997. The unit of analysis was 306 hospital referral regions (HRRs) representing health care markets for their respective tertiary medical centers. Numerators were calculated using nontraumatic major amputations and the diabetes code (250.x) for individuals with diabetes. Denominators for individuals with diabetes were created by multiplying the regional prevalence of diabetes (as determined using a 5% sample of Medicare Part B data identifying at least two visits with a diabetes code for 1995-1996) by the regional Medicare population. Denominators for individuals without diabetes were the remaining Medicare beneficiaries. Rates of major amputations were adjusted for age, sex, and race. RESULTS: Rates of major amputations per year were 3.83 per 1,000 (95% CI 3.60-4.06) individuals with diabetes compared with 0.38 per 1,000 (95% C1 0.35-0.41) individuals without diabetes. Marked geographic variation was observed for individuals with and without diabetes; however, patterns were distinct between the two populations. Rates were high in the Southern and Atlantic states for individuals without diabetes. In contrast, rates for individuals with diabetes were widely varied. Variation across HRRs for individuals with diabetes was 8.6-fold compared with 6.7-fold in individuals without diabetes for major amputations. CONCLUSIONS: Diabetes-related amputation rates exhibit high regional variation, even after age, sex, and race adjustment. Future work should be directed to exploring sources of this variation.

Age Distribution↗

The prevalence and pattern of complementary and alternative medicine use in individuals with diabetes.

OBJECTIVE: This study compared the prevalence and pattern of use of complementary and alternative medicine (CAM) in individuals with and without diabetes and identified factors associated with CAM use. RESEARCH DESIGN AND METHODS: The 1996 Medical Expenditure Panel Survey, a nationally representative sample of the U.S. noninstitutionalized civilian population, was analyzed. Estimates of CAM use in individuals with common chronic conditions were determined, and estimates of CAM use in patients with diabetes were compared with that in individuals with chronic medical conditions. Patterns of use and costs of CAM use in patients with diabetes were compared with those in nondiabetic individuals. Multiple logistic regression was used to determine independent predictors of CAM use in individuals with diabetes, controlling for age, sex, race/ethnicity, household income, educational level, and comorbidity. RESULTS: Individuals with diabetes were 1.6 times more likely to use CAM than individuals without diabetes (8 vs. 5%, P < 0.0001). In the general population, estimates of CAM use were not significantly different across selected chronic medical conditions, but diabetes was an independent predictor of CAM use. Among individuals with diabetes, older age (> or =65 years) and higher educational attainment (high school education or higher) were independently associated with CAM use. CONCLUSIONS: Diabetes is an independent predictor of CAM use in the general population and in individuals with diabetes. CAM use is more common in individuals aged > or =65 years and those with more than high school education.

Adult↗

Electromyographic analysis of the masseter and temporal muscles in oralized deaf individuals.

Deaf individuals show a number of difficulties related to the functionality of the stomatognathic system, mainly by reason of the little or no use of facial musculature during speech either due to the use of sign language or to the difficulty that these individuals have in articulating words. The stomatognathic system muscles play important roles in functions such as mastication, deglutition, and phonation. This study aimed to assess, by means of computerized bilateral electromyography (EMG), masseter and temporal muscles of 12 oralized deaf individuals in clinical activities that involve part of this masticatory musculature and compare this system's functionality with that of 12 normal listening individuals, performing the same activities. An 8-channel K6-I EMG Light Channel Surface Electromyography device was used (Myo-Tronics Co.Seattle, WA, USA), in addition to disposable double electrodes covered with silver chloride (Duotrodes; Myo-tronics Co., Seattle, WA) containing a conductor gel (Myogel- Myo-tronics Co., Seatlle, WA). The averaged rectified EMG values were normalized with reference to the EMG amplitude induced by a maximum bite force. The statistical analysis confirmed that there were any significant differences between the groups, clinical activities, and muscles, and also effects of interaction among them. The analysis made use of Variance Analysis (ANOVA). Significant differences (p < 0.01) for both muscles were found among the clinical conditions, with deaf individuals showing greater electromyographic activity for both muscles for the clinical activity protrusion. Deaf individuals showed a lower muscular activity for clinical activities that demanded a greater masseter and temporal muscular activity such as mastication, mouth opening and closing, and dental compression. Greater electromyographic values were found for both deaf individuals and healthy controls during clinical activities of mastication and dental compression. Based on the obtained data, we concluded that deaf individuals showed a lower activity of the masticatory musculature than healthy individuals; the differences were significant at the level of p < 0.01 between the performed clinical activities; and all deaf individuals and healthy controls showed greater electromyographic values for mastication and dental compression.

Adolescent↗

Functional characterization and modulation of cytokine production by CD8+ T cells from human immunodeficiency virus-infected individuals.

CD8+ T-cell clones were generated from peripheral blood mononuclear cells (PBMC) of three human immunodeficiency virus (HIV)-seronegative individuals and six HIV-seropositive individuals and assessed for their cytokine secretion profile, cytolytic potential, and chemokine production. While the great majority of CD8+ T-cell clones generated from HIV-seronegative individuals produced interferon (IFN)-gamma, but not interleukin-4 (IL-4), that is a type 1 cytotoxic (Tc1) profile, high numbers of CD8+ T-cell clones generated from HIV-seropositive individuals produced IL-4 in addition to IFN-gamma or IL-4 alone, thus showing a type 0 cytotoxic (Tc0)- or a type 2 cytotoxic (Tc2) profile, respectively. Tc0/Tc2 cells displayed lower cytolytic activity than Tc1 cells, including a reduced ability to lyse autologous targets pulsed with HIV or HIV peptides. By contrast, the production of chemokines RANTES and macrophage inflammatory protein-1alpha was comparable in Tc1, Tc0, and Tc2 clones irrespective of whether they were derived from HIV-seronegative or HIV-seropositive individuals. When CD8+ T-cell clones were generated from PBMC cultures of HIV-seronegative individuals conditioned with IL-4 plus an anti-IL-12 antibody (Ab), a shift towards the Tc0/Tc2-like profile was observed. Conversely, the addition to PBMC cultures of IL-12 plus an anti-IL-4 Ab shifted the differentiation of CD8+ T cells from HIV-infected individuals towards the Tc1-like profile, whereas IL-12 or anti-IL-4 Ab alone had a lower Tc1-promoting effect. Irradiated PBMC from HIV-infected individuals, used as feeder cells, shifted the differentiation of CD8+ T cells from a healthy HIV-seronegative individual towards the Tc0/Tc2-like profile. On the other hand, a shift towards the Tcl-like profile was noted in CD8+ T-cell clones generated from the skin specimens of two HIV-seropositive patients with Kaposi's sarcoma, successfully treated with IFN-alpha, in comparison to CD8+ clones generated from the same skin areas before treatment. The IFN-alpha-induced Tc1 shift could be prevented by the incubation of skin-infiltrating CD8+ T cells with IL-4 before cloning. Taken together, these data indicate that both defective production of IL-12 and abnormal IL-4 production in bulk PBMC populations of HIV-infected individuals may contribute to the development of high numbers of CD8+ T-cell clones showing a Tc0/Tc2-like phenotype and reduced cytolytic potential against HIV itself. They also suggest that the cytokine profile of CD8+ T-cell clones can be modulated by cytokines (or anticytokine Ab) both in vitro and in vivo.

Antibodies, Monoclonal↗

Use of community versus individual socioeconomic data in predicting variation in hospital use.

OBJECTIVES: (1) To examine the association of socioeconomic characteristics (SES) with hospitalization by age group, and when using measures of SES at the community as opposed to the individual level. (2) Thus, to support the inference that socioeconomic factors are important in the analysis of small area utilization data and address potential criticisms of this conclusion. DATA SOURCES: The 1989 Michigan Inpatient Database (MIDB), the 1990 U.S. Census, the 1989 Area Resource File (ARF), and the 1990 National Health Interview Survey (NHIS). STUDY DESIGN: A qualitative comparison of socioeconomic predictors of hospitalization in two cross-sectional analyses when using community as opposed to individual socioeconomic characteristics was done. DATA EXTRACTION. Hospitalizations (excluding delivery) were extracted by county from the MIDB and by individual from the NHIS. SES variables were extracted from the U.S. Census for communities and from the NHIS for individuals. Measures of employment for communities were from the ARF and information on health insurance and health status of individuals from the NHIS. PRINCIPAL FINDINGS: Both analyses show similar age-specific patterns for income and education. The effects were greatest in young adults, and diminished with increasing age. Accounting for multiple admissions did not change these conclusions. In the individual-level data the addition of variables representing health and insurance status substantially diminished the size of the coefficients for the socioeconomic variables. CONCLUSIONS: By comparison to parallel individual-level analyses, small area analyses with community-level SES characteristics appear to represent the effect of individual-level characteristics. They are also not substantially affected by the inability to track individuals with multiple readmissions across hospitals. We conclude that the impact of SES characteristics on hospitalization rates is consistent when measured by individual or community-level measures and varies substantially by age. These variables should be included in analyses of small area variation.

Adolescent↗

The fundamental characteristics of individual development.

Individual development in the course of a generation has an unidirectional, irreversible, "closed", predominantly structly-determined, predominantly autoprogrammed, autoreproducible character. The characteristics of individual development differ in terms of its processes, stages, types and orders. Ontogenesis and ageing of the organism represent the principal processes of individual development. Individual development has three main stages (progressive stage, "plateau" stage and regressive stage). The types of individual development may be grouped into two categories: elementary and complex. The complex types result from the combining in different ways of the elementary types. Similarly, orders of the generations of individual development and hierarchical orders of individual development may be differentiated. Between the processes, stages, types and orders of individual development certain "combining" relationships may appear. The processes, stages and types of individual development as well as their mutual relationships serve both development and stability.

Aging↗

Estimating individual influences of behavioral intentions: an application of random-effects modeling to the theory of reasoned action.

Methods are proposed and described for estimating the degree to which relations among variables vary at the individual level. As an example of the methods, M. Fishbein and I. Ajzen's (1975; I. Ajzen & M. Fishbein, 1980) theory of reasoned action is examined, which posits first that an individual's behavioral intentions are a function of 2 components: the individual's attitudes toward the behavior and the subjective norms as perceived by the individual. A second component of their theory is that individuals may weight these 2 components differently in assessing their behavioral intentions. This article illustrates the use of empirical Bayes methods based on a random-effects regression model to estimate these individual influences, estimating an individual's weighting of both of these components (attitudes toward the behavior and subjective norms) in relation to their behavioral intentions. This method can be used when an individual's behavioral intentions, subjective norms, and attitudes toward the behavior are all repeatedly measured. In this case, the empirical Bayes estimates are derived as a function of the data from the individual, strengthened by the overall sample data.

Adolescent↗

Collective memory: collaborative and individual processes in remembering.

Two experiments compared collaborative and individual recall. In Experiment 1, participants encoded pictures and words with a deep or shallow processing task, then recalled them twice either individually or collaboratively. Collaborative groups recalled more than individuals, but less than nominal groups (pooled individuals), thus exhibiting collaborative inhibition. However, group recall appeared to be more stable over time than individual recall. Groups and individuals both showed a picture-superiority effect, a level-of-processing effect, and hypermnesia. In Experiment 2, participants recalled the story "War of the Ghosts" (from F. C. Bartlett, 1932), and again collaborative groups recalled more than individuals, but less than nominal groups. Both the individual and collaborative recalls were highly organized. There was evidence that the collaborative groups tended to rely on the best individual to a greater extent in story than in list recall. Possible social and cognitive mechanisms are considered.

Adolescent↗

Adolescent individuation and alcohol use.

OBJECTIVE: This study evaluates a developmental psychosocial model of adolescent drinking. Specifically, the role of two aspects of adolescent individuation-separation and intergenerational individuation-is examined within the context of family dynamics, stress and peer associations. These measures parallel an ongoing debate regarding the nature of individuation. The separation measure captures aspects of individuation related to detachment or rebelliousness. Intergenerational individuation measures increasing self-reliance and control with maintenance of supportive family bonds. METHOD: A structural equation model describing adolescent alcohol use as a function of two measures of individuation, family conflict, communication with mother, stress and peer use of alcohol was tested in two independent samples. The first included 6th- through 12th-grade adolescents and the second was composed of 6th- through 8th-grade students. RESULTS: In both studies, significant direct and indirect paths were found from individuation measures and family, peer use and stress constructs to adolescent alcohol use. Separation had a stronger relationship to alcohol use than did intergenerational individuation and was associated with higher levels of stress and alcohol use by peers. CONCLUSIONS: The findings support the role of individuation as a contributing factor in adolescent alcohol use. They indicate the importance of family and parent-adolescent relationships in adolescent alcohol use and suggest directions for both family-based and school-based preventive interventions.

Adolescent↗

Epstein-Barr virus seroreactivity among unaffected individuals within high-risk nasopharyngeal carcinoma families in Taiwan.

Most adults have been infected with EBV. Many studies have indicated that antibodies against specific EBV antigens, particularly IgA antibodies, can be predictive or prognostic of EBV-associated malignancies, such as NPC. We hypothesized that healthy individuals from families with a history of multiple members affected with NPC (who therefore might be genetically susceptible to NPC themselves) might have an EBV antibody profile that is distinct from that seen in healthy individuals from the community at large. To explore this possibility and examine determinants of anti-EBV antibody levels in healthy, high-risk individuals, we evaluated data from 2 parallel studies of NPC in Taiwan, which included 1,229 healthy members of families in which 2 or more individuals were affected with NPC and 320 controls from the community at large. Blood collected from participants was tested for IgA antibodies against EBV VCA and EBNA-1 and for neutralizing antibodies against EBV DNase using standard assays. We observed evidence of familial aggregation of EBV seroreactivity among individuals from high-risk, multiplex NPC families. Anti-VCA IgA and anti-EBNA-1 IgA antibody seroprevalence in unaffected family members of NPC cases was 5-6 times higher than in members of the community (p < 0.01). This elevated seroprevalence among unaffected individuals from high-risk families was observed regardless of the relationship of the unaffected individual to the closest affected relative (siblings, parents, children or spouses). No sociodemographic or environmental factors examined were found to strongly and consistently correlate with elevated seroprevalence, but patterns emerged of increasing seroprevalence among older individuals and among females. Unaffected individuals from high-risk NPC families have elevated anti-EBV IgA antibody titers. The etiologic and clinical implications of this finding remain to be established.

Adolescent↗

Reduced HIV-1 infectability of CD4+ lymphocytes from exposed-uninfected individuals: association with low expression of CCR5 and high production of beta-chemokines.

We examined the human immunodeficiency virus type 1 infectability of CD4+ lymphocytes isolated from CCR5 wild-type individuals, individuals heterozygous for the delta32 allele of CCR5, and HIV-1-exposed but uninfected (EU) individuals who had CD4+ lymphocytes refractory to M-tropic viral replication. None of the EU individuals were found to be heterozygous for the delta32 allele. The CD4+ lymphocytes isolated from CCR5/delta32 and EU individuals were less infectable with an M-tropic viral isolate of HIV-1 than CCR5/CCR5 control individuals but were equally as infectable with a T-tropic viral isolate. The restriction to M-tropic viral isolate replication did not associate with any profound genotypic change in the CCR5 gene. CD4+ lymphocytes from CCR5/delta32 and CCR5/CCR5 EU individuals were more sensitive to the HIV-inhibitory effects of the recombinant beta-chemokines RANTES, MIP-1alpha, and MIP-1beta than were CD4+ lymphocytes from CCR5/CCR5 control individuals. CD4+ lymphocytes from EU individuals also showed increased sensitivity to recombinant beta-chemokines and low surface expression of CCR5. A phenotype of low CCR5 expression and high secretion of beta-chemokines is associated with reduced infectability of cells by M-tropic HIV-1. This phenotype may also be associated with protection against sexual transmission of HIV-1.

CD4-Positive T-Lymphocytes↗

A community model of ciliate Tetrahymena and bacteria E. coli: Part I. individual-based models of tetrahymena and E. coli populations.

The dynamics of a microbial community consisting of a eucaryotic ciliate Tetrahymena pyriformis and procaryotic Escherichia coli in a batch culture is explored by employing an individual-based approach. In this portion of the article, Part I, population models are presented. Because both models are individual-based, models of individual organisms are developed prior to construction of the population models. The individual models use an energy budget method in which growth depends on energy gain from feeding and energy sinks such as maintenance and reproduction. These models are not limited by simplifying assumptions about constant yield, constant energy sinks and Monod growth kinetics as are traditional models of microbal organisms. Population models are generated from individual models by creating distinct individual types and assigning to each type the number of real individuals they represent. A population is a compilation of individual types that vary in a phase of cell cycle and physiological parameters such as filtering rate for ciliates and maximum anabolic rate for bacteria. An advantage of the developed models is that they realistically describe the growth of the individual cells feeding on resource which varies in density and composition. Part II, the core of the project, integrates models into a dynamic microbial community and provides model analysis based upon available data.

Animals↗

Antibodies to infectious agents in individuals with recent onset schizophrenia.

We investigated the levels of antibodies to infectious agents in the serum and cerebral spinal fluids (CSFs) of individuals with recent onset schizophrenia and compared these levels to those of controls without psychiatric disease. We found that untreated individuals with recent onset schizophrenia had significantly increased levels of serum and CSF IgG antibody to cytomegalovirus and Toxoplasma gondii as compared to controls. The levels of serum IgM class antibodies to these agents were not increased. Untreated individuals with recent onset schizophrenia also had significantly lower levels of serum antibody to human herpesvirus type 6 and varicella zoster virus as compared to controls. Levels of antibodies to herpes simplex virus type 1, herpes simplex virus type 2, and Epstein Barr virus, and did not differ from cases and controls. We also found that treatment status had a major effect on the levels of antibodies in this population. Individuals who were receiving treatment had lower levels of antibodies to cytomegalovirus and Toxoplasma gondii, and higher levels of serum antibodies to human herpesvirus type 6 as compared to untreated individuals. The level of antibodies to Toxoplasma and human herpesvirus type 6 measured in treated individuals did not differ from the levels measured in controls. In the case of cytomegalovirus, the levels of CSF antibodies in treated individuals did not differ from those of controls, while the level of serum IgG antibodies to CMV remained slightly greater than controls in this population. Our studies indicate that untreated individuals with recent onset schizophrenia have altered levels of antibodies to cytomegalovirus, Toxoplasma gondii, and human herpesvirus type 6 while the levels of these antibodies in treated individuals with recent onset schizophrenia are similar to those of controls. These findings indicate that infectious agents may play a role in the etiopathogenesis of some cases of schizophrenia.

Adult↗

Influence of change from grouped to individual housing on a T-cell-dependent immune response in mice: antagonism by diazepam.

Transferring CD-1 mice from grouped to individual housing and then maintaining them individually resulted in a decline in the peak IgM plaque-forming cell (PFC) response to sheep red blood cells (SRBCs). However, the immunosuppression was dependent on the amount of time mice were maintained individually. In particular, individual housing for 5-10 days prior to SRBC inoculation and for 4 days following inoculation resulted in a suppression of the splenic PFC response and serum antibody titers. Shorter periods of individual housing (4 days following inoculation) did not provoke the immunosuppression. Likewise, following more protracted individual housing (15-30 days prior to inoculation) the immunosuppression was not evident. Inasmuch as daily treatment with an anxiolytic, diazepam (1.0 mg/kg), antagonized the suppression induced by 5 days of individual housing, it was suggested that the change from group to individual housing and then maintenance of animals individually acted much like a stressor to induce the immunosuppression.

Animals↗