The influence of regulatory T cells and diurnal hormone rhythms on T helper cell activity

Symptoms of diseases such as rheumatoid arthritis, which is T helper 1 (Th1) dependent, and asthma, which is T helper 2 (Th2) dependent, are influenced by diurnal rhythms and natural regulatory T cells (nTreg). However, the mechanisms responsible for the diurnal rhythm of disease activity have not been identified and it is unclear whether nTreg activity is diurnal rhythm‐dependent. We therefore investigated whether a 24‐hr diurnal cycle affected the ability of various helper T‐cell populations to generate immunomodulatory and pro‐inflammatory cytokines, as well as its suppression by nTreg cells. Using a within‐subject crossover design, sleep versus continuous wakefulness was compared over a 24‐hr period in healthy young volunteers under defined environmental conditions. Venous blood was drawn periodically every 5 hr and the function of T cells was explored in vitro. We demonstrated that interleukin (IL)‐2, interferon‐γ (IFN‐γ), tumour necrosis factor‐α (TNF‐α) and IL‐10 secretion by naïve CD4⁺ T cells follows a diurnal rhythm. Furthermore, multiple regression analysis, as well as subsequent in vitro experiments, suggested that serum levels of cortisol and prolactin are part of the underlying mechanism. Additionally, we observed that nTreg suppressed the secretion of IFN‐γ, IL‐2 and TNF‐α, but not the secretion of IL‐4, IL‐6, IL‐10 and IL‐17A. However, the abrogation of IL‐2 release was reversed upon inhibiting CD25 on nTreg. Highly purified nTreg secreted IL‐6, IL‐10 and IL‐17A, but not IL‐2, IL‐4, IFN‐γ or TNF‐α. Taken together, our results demonstrate that hormones and nTreg modulate the diurnal rhythm of T helper cell activity.     

Shared decision making coding systems: How do they compare in the oncology context?

Objective

The current study aimed to evaluate three coding systems which have been used to assess shared decision making in oncology consultations (OPTION, Decision Support Analysis Tool (DSAT) and Decision Analysis System for Oncology (DAS-O)): (i) comparing their ability to identify competencies of shared decision making, and (ii) determining their ability to predict patient outcomes in a single data set.

Method

Twenty oncologists from Australia and New Zealand participated in the IBCSG Trial 33-03. The consultations of 55 women with early stage breast cancer were audio-taped, transcribed and then coded using the OPTION, DAS-O and DSAT coding systems by three different raters. Women completed the questionnaires 2 weeks and 4 months after their consultation.

Results

DAS-O was strongly correlated with OPTION (r = 0.73). DSAT was moderately correlated with DAS-O and OPTION (r < 0.6). Decisional satisfaction and satisfaction with doctor SDM skills were significantly correlated with OPTION (r = 0.39 and 0.42 respectively) and the latter variable was correlated with DAS-O (r = 0.40). These relationships persisted in multiple linear regression analyses.

Conclusions

OPTION may be the most efficient and sensitive coding system for research purposes; however, DSAT appeared to document behaviours reducing decisional conflict and both DSAT and DAS-O offer more detailed feedback to doctors.

Practice implications

Optimal coding system will depend on research goals and training purposes.     

The program for phenotyping of genetically modified animals at AstraZeneca

Genetically modified mice offer a wide range of possibilities in preclinical drug discovery, e.g. for use in target identification, target validation and disease model generation. However, genomic modification and alteration in gene expression may cause unpredicted phenotypic alterations in the organism other than the intended ones. The aim of this study was to determine the importance of establishing the phenotype of transgenic and knockout mice models for use in pharmaceutical research.

A total number of 51 mouse models (transgenic and knockout) produced at AstraZeneca during a 4 year period were subjected to a thorough phenotyping package covering clinical as well as morphological aspects. Phenotype abnormalities were recorded in 36 (70.6%) of the mouse models. The majority of findings were considered to be minor in magnitude. Histopathological changes related to the genotype of the animals were observed in 33% of the mouse models, underlining the importance of pathology in the phenotyping program.     

Correlates and trend of HIV prevalence among female sex workers attending sexually transmitted disease clinics in Pune, India (1993-2002)

In India, substantial efforts have been made to increase awareness about HIV/AIDS among female sex workers (FSWs). We assessed the impact of awareness regarding safe sex in a cohort of FSWs by studying trends in HIV prevalence, sexually transmitted diseases (STDs), and risk behaviors measured from 1993 to 2002 in Pune, India. A total of 1359 FSWs attending 3 STD clinics were screened for HIV infection, and data on demographics, sexual behaviors, and past and current STDs were obtained. The overall HIV prevalence among FSWs was 54%. Not being married (adjusted odds ratio [AOR] = 1.74, 95% confidence interval [CI]: 1.17 to 2.59), being widowed (AOR = 2.10, 95% CI: 1.16 to 3.80), inconsistent condom use (AOR = 1.60, 95% CI: 1.02 to 2.50), clinical presence of genital ulcer disease (GUD; AOR = 1.66, 95% CI: 1.07 to 2.56), and genital warts (AOR = 4.70, 95% CI: 1.57 to 14.08) were independently associated with HIV infection among FSWs. The prevalence of HIV remained stable over 10 years (46% in 1993 and 50% in 2002; P = 0.80). The prevalence of GUD decreased over time (P < 0.001), whereas that of observed genital discharge remained stable. Reported consistent condom use as well as the proportion of FSWs who refused sexual contact without condoms increased over time (P < 0.001). These data collectively suggest that safe sex interventions have had a positive impact on FSWs in Pune, India.     

Environmental allergens and asthma in urban elementary schools.

BACKGROUND: Asthma in school children is rising, and indoor allergens are very common triggers of asthma attacks; however, the risk of the school environment on asthma has not been well studied. OBJECTIVE: To determine the presence and the levels of common aeroallergens in schools, where asthma prevalence rates are high. METHODS: Settled dust samples were collected from 12 Baltimore City public elementary schools, and they were analyzed for the following allergens: cockroaches (Bla g 1/2), dust mites (Der f 1/p 1), dog (Can f 1), cat (Fel d 1), and mouse (Mus m 1). School asthma prevalence rates were correlated with allergen levels, and association between allergen levels and other risk factors present in the schools' environment was examined. RESULTS: The mean and range levels were 1.49 U/g (0 to 8) for Bla g 1/2; 0.38 microg/g (0 to 11.9) for the Der f 1/p 1; 1.44 microg/g (0.1 to 9.6) for Can f 1; 1.66 microg/g (0.2 to 12) for Fel d 1; and 6.24 microg/g (0.3 to 118.3) for Mus m 1. Dust mite, cat and dog allergens were significantly in rooms with carpet and/or area rugs, compared to rooms with bare floors (P < 0.05). Asthma prevalence rates varied from 11.8 to 20.8% between schools and positively correlation with the mean levels of Bla g 1/2 in the schools (P = 0.001). CONCLUSIONS: Common allergens that are known to trigger asthma were detected in all school environments, where asthma prevalence rates were high. However, the overall allergen levels were low, indicating that other factors, including exposures in the homes of asthmatic patients, may have more relevance to sensitization and symptoms than school exposures.     

Social Relationship Factors,Preoperative Depression,and Hospital Length of Stay in Surgical Patients

Purpose

The interrelated associations of social relationship factors, depression, and outcomes of surgical patients are yet unexplored. The purpose of this study was to investigate whether depression mediates effects of general social support, loneliness, and living alone on hospital length of stay (LOS) of 2487 patients from diverse surgical fields.

Method

Social relationship factors and depression were assessed prior to surgery. The PROCESS macro for SPSS was used to conduct three simple mediation models that tested the indirect effects of social relationship factors on LOS mediated through depression. The models were adjusted for age, gender, preoperative physical health, surgical field, severity of medical comorbidity, and extent of surgical procedure.

Results

Social support and loneliness had significant indirect effects on LOS that were statistically mediated by preoperative depression. Lower social support and the feeling of loneliness were considerably related to higher depression which predicted longer LOS. While social support and loneliness had no direct effects on LOS, there was a small significant direct association of living alone with shorter LOS.

Conclusion

Data suggest that social support and loneliness are indirectly related with surgical outcomes by an association with depression which in turn is related to worse outcomes.

Trial Registration

NCT01357694

     

CX3CL1 (fractalkine) and CX3CR1 expression in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis: kinetics and cellular origin

Background  

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). It is associated with local activation of microglia and astroglia, infiltration of activated macrophages and T cells, active degradation of myelin and damage to axons and neurons. The proposed role for CX₃CL1 (fractalkine) in the control of microglia activation and leukocyte infiltration places this chemokine and its receptor CX₃CR1 in a potentially strategic position to control key aspects in the pathological events that are associated with development of brain lesions in MS. In this study, we examine this hypothesis by analyzing the distribution, kinetics, regulation and cellular origin of CX₃CL1 and CX₃CR1 mRNA expression in the CNS of rats with an experimentally induced MS-like disease, myelin oligodendrocyte glycoprotein (MOG)-induced autoimmune encephalomyelitis (EAE).     

ROC analysis of dexamethasone suppression test threshold in suicide prediction after attempted suicide

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis function is associated with suicidal behavior. In suicide attempters with mood disorder, the non-suppressor status in the dexamethasone suppression test (DST) is associated with suicide indicating that HPA-axis hyperactivity is a biological risk factor for suicide and may be a useful predictor. The threshold of 5 microg/dl for cortisol levels measured at 08:00 a.m. or 4:00 p.m. following dexamethasone at 11:00 p.m. to define the DTS nonsuppression was derived as being optimal for the separation of melancholia and nonmelancholic conditions rather than the prediction of suicide. A different threshold may offer a better identification of suicide. The aim of this study was to find the optimal threshold level of post DST plasma cortisol at 4 p.m. for suicide prediction using receiver operating characteristics (ROC) analysis. A cohort of 106 depressed inpatients with an index suicide attempt admitted to the department of Psychiatry at the Karolinska University Hospital between 1980 and 2000, were submitted to DST and followed up for causes of death. During the follow-up (mean 17 years), 25 suicides (24%) were identified. The ROC analysis revealed that a lower threshold of 3.3 microg/dl for the nonsuppressor status predicted 17 of 25 suicides (sensitivity of 68%) compared with 15 of 25 suicides (sensitivity 60%) with a conventional threshold of 5 microg/dl at 4:00 p.m. In male suicide attempters the lower threshold for pathological DST result (3.3 microg/dl) changed the Odds ratio from 6.7 till 18. In female suicide attempters a higher threshold (7.3 microg/dl) optimised the value of DST as a biological test for suicide prediction indicating a gender difference.     

Cytoskeletal changes during neurogenesis in cultures of avian neural crest cells

Summary Neural crest cells are motile and mitotic, whereas their neuronal derivatives are terminally post-mitotic and consist of stationary cell body from which processes grow. The present study documents changes in the cytoskeleton that occur during neurogenesis in cultures of avian neural crest cells. The undifferentiated neural crest cells contain dense bundles of actin filaments throughout their cytoplasm, and a splayed array of microtubules attached to the centrosome. In newly differentiating neurons, the actin bundles are disrupted and most of the remaining actin filaments are reorganized into a cortical layer underlying the plasma membrane of the cell body and processes. Microtubules are more abundant in newly-differentiating neurons than in the undifferentiated cells, and individual microtubules can be seen dissociated from the centrosome. Neuron-specific -III tubulin appears in some crest cells prior to cessation of motility and cell division, and expression increases with total microtubule levels during neurogenesis. To investigate how these early cytoskeletal changes might contribute to alterations in morphology during neurogenesis, we have disrupted the cytoskeleton with pharmacologic agents. Microfilament disruption by cytochalasin immediately arrests the movement of neural crest cells and causes them to round-up, but does not significantly change the morphology of the immature neurons. Microtubule depolymerization by nocodazole slows the movement of undifferentiated cells and causes retraction of processes extended by the immature neurons. These results suggest that changes in the actin and microtubule arrays within neural crest cells govern distinct aspects of their morphogenesis into neurons.     

Neutralization assay using a modified vaccinia virus Ankara vector expressing the green fluorescent protein is a high-throughput method to monitor the humoral immune response against vaccinia virus

Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.