Reconstitution of a functional interleukin (IL)-7 receptor demonstrates that the IL-2 receptor gamma chain is required for IL-7 signal transduction

The interleukin (IL)-2 receptor gamma chain has recently been shown to be a component of the IL-7 and IL-4 receptors. Using a transient transfection assay and the trans-activation of reporter gene constructs which are under the control of cytokine-responsive promoter elements, we have studied signal transduction through the IL-7 receptor (IL-7R). The reporter gene expression was not stimulated by receptors that contained the cytoplasmic domain of the IL-7R, either as intact IL-7R or as part of a chimeric receptor. However, co-expression of the IL-7R with the IL-2 receptor gamma chain was able to stimulate gene activation. For maximal stimulation the intact cytoplasmic domains of each chain was required.     

Impact of noise and nonlinear distortion due to clipping on the BERperformance of a 64-QAM signal in hybrid AM-VSB/QAM optical fibertransmission system

Experimental BER measurements of a 64-QAM signal in a hybrid AM-VSB/QAM optical fiber transmission system are shown to be in good agreement with a corrected and reinterpreted theory of impulsive and Gaussian noise based on Middleton's class B impulsive noise model. Fiber dispersion induced distortion of the chirped laser output is also shown to adversely affect the QAM signal     

Low-temperature behavior of alkali halides doped with hydroxyl

The low-temperature dielectric dispersions of LiF, NaCl, KCl, and KBr have been measured for different concentrations of OH^?. With decreasing tunnel splitting of the OH^? levels, and with increasing dipolar interaction, a behavior is observed below ～1 K similar to that found in amorphous materials and attributed to two-level states (TLS). Differences between OH^? and TLS are noted, the main difference being that the broad spectrum of energy levels associated with the OH^? in alkali halides arises from dipolar interactions rather than an atomically disordered environment. It is argued that an electric dipole analog of the magnetic spin-glass state does not occur in the OH^? systems.     

Demographic impact of the HIV epidemic in Thailand

OBJECTIVE: To assess the impact of the HIV epidemic on the demographic development of the Thai population. METHODS: A deterministic mathematical model was used to predict simultaneously epidemiological and demographic processes. Partial differential equations express the relationships between biological, behavioural and demographic variables. The model allows the evaluation of different sexual mixing patterns, variable transmission probabilities and incubation times. Validity analysis was performed by generating antecedent HIV prevalence patterns among military recruits and pregnant women. RESULTS: On the national level in Thailand we predict that the cumulative number of people in Thailand with HIV infection will exceed 1 million by 1999; the number of deaths from AIDS will be 555000 by the year 2000 but will not reach 1 million until after the year 2014. Without the HIV epidemic the population growth rate was estimated at 1.3% per annum until 1995, after which a decline to 0.9% by 2005 is predicted. The HIV epidemic started to affect the population growth rate by 0.026% per year in 1991, and the difference is predicted to rise to about 0.12% per year during the period 1995-2000, to decline to 0.06% in 2005 and then to disappear. In the mid-1990s HIV affected mainly the 15-35-year-old age group, but over time younger and older age groups have been affected as a result of perinatal transmission, and a decline in fertility as well as ageing of the 15-35-year-old birth cohort. Because of HIV, in 2000 there will be 612000 (1%) fewer people than expected and by 2010, 1140000 fewer (1.6%). We predict that the demographic impact of the HIV epidemic in the northern region will follow the same pattern, but with greater severity. Here, the effect on the population growth rate and the population age distribution is likely to be twice as high as at the national level. CONCLUSIONS: It is estimated that 1 million Thais will be infected with HIV by the year 2000 and an almost equal number will have died of AIDS by the year 2014. Although these numbers seem high, their direct and indirect effects on the demographic structure of the Thai population are small. However, at a regional level, for example in the northern region, the effect of the HIV epidemic may be more severe.     

Parents' nonshared treatment of siblings and the development of social competence during adolescence.

This article proposes that there is a distinction between shared (SH) and nonshared (NSH) parenting. This study investigated the contribution of these aspects of parenting to indexes of social competence in adolescents by means of a multimethod, multimeasure study. NSH parenting was predictive of child adjustment at least as strongly as was SH parenting. The NSH components, however, were child-directed relations instead of sibling-directed relations. Parental treatment of a sibling thus added information about SH environmental processes, but did not provide information about independent NSH processes. NSH components predicted social responsibility and cognitive agency rather than autonomy, sociability, and self-worth. NSH conflict, shared monitoring and control, and both SH and NSH warmth were important for the prediction of adjustment. These relations were consistent across gender and were characteristic of a broad array of family types. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of neutrophil-endothelial cell adhesion in inflammatory disorders

Polymorphonuclear leukocytes are armed with an impressive arsenal of bactericidal agents that allow these cells to play a vital role in host defense against invading pathogens. However, these same agents can produce extensive cellular damage in host tissues when leukocytes are activated during inflammatory conditions. Recognition of this fact, when coupled with the observation that leukocyte adhesion to post-capillary venules is a critical first step in the inflammatory process, has led to the development of the concept that inhibition of neutrophil-endothelial cell adhesion (NECA) may represent a novel therapeutic strategy for the prevention of leukocyte-dependent injury in inflammatory conditions. Indeed, pharmacological or immunologic inhibition of NECA reduces cellular injury, dysfunction, and necrosis induced by ischemia/reperfusion, circulatory shock and resuscitation, organ transplantation, cardiopulmonary bypass, frostbite, and thermal trauma. NECA also appears to play an important role in the pathobiology of airway inflammation and asthma, pulmonary oxygen toxicity, arthritis, bacterial meningitis, and cerebral malaria. The aim of this review is to summarize the evidence implicating NECA in the pathogenesis of these inflammatory conditions.