Tuberculosis is a major cause of death in much of the world. Current estimates are that one-third of the world's population is infected with Mycobacterium tuberculosis. Most infected persons control the infection but in many cases may not eliminate the organism. Reactivation of this clinically latent infection is responsible for a large proportion of active tuberculosis cases. A major risk factor for reactivation of latent tuberculosis is HIV infection, suggesting a role for the CD4+ T cell subset in maintaining the latent persistent infection. In this study, we tested the requirement for CD4+ T cells in preventing reactivation in a murine model of latent tuberculosis. Antibody-mediated depletion of CD4+ T cells resulted in rapid reactivation of a persistent infection, with dramatically increased bacterial numbers in the organs, increased pathology in the lungs, and decreased survival. Although CD4+ T cells are believed to be a major source of interferon (IFN)-γ, expression of the gene for IFN-γ in the lungs of CD4+ T cell–depleted mice was similar to that in control mice. In addition, inducible nitric oxide synthase production and activity was unimpaired after CD4+ T cell depletion, indicating that macrophage activation was present even during CD4+ T cell deficiency. These data indicate that CD4+ T cells are necessary to prevent reactivation but may have roles in addition to IFN-γ production and macrophage activation in controlling a persistent tuberculous infection.

Members of the transforming growth factor-beta (TGF-beta) superfamily signal through heteromeric type I and type II serine/threonine kinase receptors. Transgenic mice that overexpress a dominant-negative mutation of the TGF-beta type II receptor (DNIIR) under the control of a metallothionein-derived promoter (MT-DNIIR) were used to determine the role of endogenous TGF-betas in the developing mammary gland. The expression of the dominant-negative receptor was induced with zinc and was primarily localized to the stroma underlying the ductal epithelium in the mammary glands of virgin transgenic mice from two separate mouse lines. In MT-DNIIR virgin females treated with zinc, there was an increase in lateral branching of the ductal epithelium. We tested the hypothesis that expression of the dominant-negative receptor may alter expression of genes that are expressed in the stroma and regulated by TGF-betas, potentially resulting in the increased lateral branching seen in the MT-DNIIR mammary glands. The expression of hepatocyte growth factor mRNA was increased in mammary glands from transgenic animals relative to the wild-type controls, suggesting that this factor may play a role in TGF-beta-mediated regulation of lateral branching. Loss of responsiveness to TGF-betas in the mammary stroma resulted in increased branching in mammary epithelium, suggesting that TGF-betas play an important role in the stromal-epithelial interactions required for branching morphogenesis.

Mycobacterium tuberculosis causes active tuberculosis in only a small percentage of infected persons. In most cases, the infection is clinically latent, although immunosuppression can cause reactivation of a latent M. tuberculosis infection. Surprisingly little is known about the biology of the bacterium or the host during latency, and experimental studies on latent tuberculosis suffer from a lack of appropriate animal models. The Cornell model is a historical murine model of latent tuberculosis, in which mice infected with M. tuberculosis are treated with antibiotics (isoniazid and pyrazinamide), resulting in no detectable bacilli by organ culture. Reactivation of infection during this culture-negative state occurred spontaneously and following immunosuppression. In the present study, three variants of the Cornell model were evaluated for their utility in studies of latent and reactivated tuberculosis. The antibiotic regimen, inoculating dose, and antibiotic-free rest period prior to immunosuppression were varied. A variety of immunosuppressive agents, based on immunologic factors known to be important to control of acute infection, were used in attempts to reactivate the infection. Although reactivation of latent infection was observed in all three variants, these models were associated with characteristics that limit their experimental utility, including spontaneous reactivation, difficulties in inducing reactivation, and the generation of altered bacilli. The results from these studies demonstrate that the outcome of Cornell model-based studies depends critically upon the parameters used to establish the model.

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This study extends the literature on women's perception of the influence of smoking on breast feeding by assessing breast-feeding intent, initiation, duration, and reasons for weaning longitudinally among women who quit smoking as a result of pregnancy. The results support a need for additional research to determine the effectiveness of breast feeding supports as a component of interventions to reduce postpartum smoking relapse.

Objective Test the hypothesis that alcoholism, including antisocial alcoholism, is more prevalent among mothers and fathers of children with versus without ADHD. Method Mothers (312 ADHD group, 235 non-ADHD group) and fathers (291 ADHD group, 227 non-ADHD group) in the Pittsburgh ADHD Longitudinal Study were interviewed along with their adolescent and young adult offspring. Results Maternal and paternal alcoholism, with and without comorbid antisociality, was more prevalent in the ADHD group. Paternal alcoholism without antisociality was only marginally higher for probands after controlling for paternal ADHD. Offspring conduct disorder comorbidity was associated with parental antisociality but not parental antisocial alcoholism. Conclusions Our findings that 44% of proband fathers and 25% of proband mothers experienced alcohol problems with or without antisociality, are further evidence of increased alcoholism prevalence in families affected by ADHD. Maternal alcoholism and antisociality are prominent contributors to this family-level vulnerability. These findings indicate the need to assess long-term offspring outcomes as a function of parental alcohol and externalizing comorbidities, and perhaps other indicators of parental alcoholism phenotype, as familial vulnerability unfolds across development.

Objectives: We examined the association of parent training (PT)-related factors with therapeutic success in the Treatment of Severe Childhood Aggression (TOSCA) study. Our aims were (1) to evaluate demographic and clinical characteristics as predictors of parent attendance and engagement in PT and (2) to examine the associations of parent attendance and engagement in PT with study-targeted child behavior outcomes (i.e., attention-deficit/hyperactivity disorder [ADHD] and disruptive behavior symptoms). TOSCA was a randomized clinical trial evaluating the effect of placebo versus risperidone when added to PT and psychostimulant for childhood ADHD with severe aggression. Methods: Data for 167 parents and children 6-12 years old with ADHD, oppositional defiant disorder (ODD) or conduct disorder, and severe physical aggression were examined. Analyses used generalized linear models. Results: Most parents (72%) attended seven or more of nine sessions. The average parental engagement, that is, the percentage of PT elements fully achieved across participants and sessions, was 85%. The average therapist rating of goal completion was 92%. Parents of non-white and/or Hispanic children (p = 0.01) and children with lower intelligence quotient (p = 0.02) had lower PT attendance; parents with lower family incomes (p = 0.01) were less engaged. Attendance and engagement predicted better scores on the primary child behavior outcomes of disruptive behavior (Nisonger Child Behavior Rating Form Disruptive Behavior Total) and ADHD and ODD symptoms, adjusting for baseline severity. Conclusions: When the clinical picture is sufficiently severe to warrant prescribing an atypical antipsychotic, PT is feasible for families of children with ADHD and co-occurring severe aggression. The promotion of attendance and engagement in PT is important to enhance clinical outcomes among this challenging population. Methods for overcoming barriers to participation in PT deserve vigorous investigation, particularly for those with low family income, non-white race, Hispanic ethnicity, or when children have lower cognitive level.

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