Ovarian hormones and cognition in the aged female rat: II. progesterone supplementation reverses the cognitive enhancing effects of ovariectomy

The authors hypothesized that the progesterone component of some hormone replacement therapies in women is detrimental to cognition. A previous study showed that ovariectomy (ovx) in aged rats enhanced spatial working memory and decreased elevated progesterone levels. The current study evaluated whether progesterone administration counteracts these cognitive enhancing effects of ovx. Aged sham and aged ovx rats given progesterone exhibited compromised learning of the working and reference memory components of the task, and made more working memory errors on the latter testing days compared with aged ovx rats not given progesterone. Results suggest that whereas ovx of the aged female rat enhances learning and the ability to handle numerous items of spatial working memory information, progesterone is detrimental to these aspects of performance. These findings may speak to studies in menopausal women which suggest that combination hormone therapies have a negative impact on cognition.     

Absence of proteinase-activated receptor-1 signaling affords protection from bleomycin-induced lung inflammation and fibrosis

Activation of the coagulation cascade is commonly observed in the lungs of patients with both acute and chronic inflammatory and fibrotic lung disorders, as well as in animal models of these disorders. The aim of this study was to examine the contribution of the major thrombin receptor, proteinase-activated receptor-1 (PAR-1), during the acute inflammatory and chronic fibrotic phases of lung injury induced by intratracheal instillation of bleomycin in mice. Inflammatory cell recruitment and increases in bronchoalveolar lavage fluid (BALF) protein were attenuated by 56 +/- 10% (P < 0.05) and 53 +/- 12% (P < 0.05), respectively, in PAR-1-deficient (PAR-1-/-) mice compared with wild-type (WT) mice. PAR-1-/- mice were also protected from bleomycin-induced pulmonary fibrosis with total lung collagen accumulation reduced by 59 +/- 5% (P < 0.05). The protection afforded by PAR-1 deficiency was accompanied by significant reductions in pulmonary levels of the potent PAR-1-inducible proinflammatory and profibrotic mediators, monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-beta-1 (TGF-beta1), and connective tissue growth factor/fibroblast-inducible secreted protein-12 (CTGF/FISP12). In addition, PAR-1 was highly expressed in inflammatory and fibroproliferative lesions in lung sections obtained from patients with fibrotic lung disease. These data show for the first time that PAR-1 signaling plays a key role in experimentally induced lung injury, and they further identify PAR-1 as one of the critical receptors involved in orchestrating the interplay between coagulation, inflammation, and remodeling in response to tissue injury.     

Characterization of BrkA Expression in Bordetella bronchiseptica

BrkA confers resistance to killing by complement in Bordetella pertussis. Complement resistance in Bordetella bronchiseptica was examined. Four B. bronchiseptica strains possessed the brkA gene; however, only three expressed the protein. Only the strain lacking BrkA was susceptible to complement. Introduction of the B. pertussis brkA gene restored BrkA expression to this strain but did not confer resistance. brkA was mutated in the strains that naturally expressed BrkA, and loss of BrkA did not confer sensitivity to complement. As a species, B. bronchiseptica is more resistant to complement than B. pertussis, and BrkA does not mediate resistance.     

In vitro degradation of silk fibroin

A significant need exists for long-term degradable biomaterials which can slowly and predictably transfer a load-bearing burden to developing biological tissue. In this study Bombyx mori silk fibroin yarns were incubated in 1mg/ml Protease XIV at 37 degrees C to create an in vitro model system of proteolytic degradation. Samples were harvested at designated time points up to 12 weeks and (1) prepared for scanning electron microscopy (SEM), (2) lyophilized and weighed, (3) mechanical properties determined using a servohydraulic Instron 8511, (4) dissolved and run on a SDS-PAGE gel, and (5) characterized with Fourier transform infrared spectroscopy. Control samples were incubated in phosphate-buffered saline. Fibroin was shown to proteolytically degrade with predictable rates of change in fibroin diameter, failure strength, cycles to failure, and mass. SEM indicated increasing fragmentation of individual fibroin filaments from protease-digested samples with time of exposure to the enzyme; particulate debris was present within 7 days of incubation. Gel electrophoresis indicated a decreasing amount of the silk 25 kDa light chain and a shift in the molecular weight of the heavy chain with increasing incubation time in protease. Results support that silk is a mechanically robust biomaterial with predictable long-term degradation characteristics.     

Silencing of Fas, but not caspase-8, in lung epithelial cells ameliorates pulmonary apoptosis, inflammation, and neutrophil influx after hemorrhagic shock and sepsis

Apoptosis and inflammation play an important role in the pathogenesis of direct/pulmonary acute lung injury (ALI). However, the role of the Fas receptor-driven apoptotic pathway in indirect/nonpulmonary ALI is virtually unstudied. We hypothesized that if Fas or caspase-8 plays a role in the induction of indirect ALI, their local silencing using small interfering RNA (siRNA) should be protective in hemorrhage-induced septic ALI. Initially, as a proof of principle, green fluorescent protein-siRNA was administered intratracheally into transgenic mice overexpressing green fluorescent protein. Twenty-four hours after siRNA delivery, lung sections revealed a significant decrease in green fluorescence. Intratracheally administered Cy-5-labeled Fas-siRNA localized primarily in pulmonary epithelial cells. Intratracheal instillation of siRNA did not induce lung inflammation via toll-like receptor or protein kinase PKR pathways as assessed by lung tissue interferon-alpha, tumor necrosis factor-alpha, and interleukin (IL)-6 levels. Mice subjected to hemorrhagic shock and sepsis received either Fas-, caspase-8-, or control-siRNA intratracheally 4 hours after hemorrhage. Fas- or caspase-8-siRNA significantly reduced lung tissue Fas or caspase-8 mRNA, respectively. Only Fas-siRNA markedly diminished lung tissue tumor necrosis factor-alpha, IL-6, IL-10, interferon-gamma, IL-12, and caspase-3 activity. Fas-siRNA also preserved alveolar architecture and reduced lung neutrophil infiltration and pulmonary epithelial apoptosis. These data indicate the pathophysiological significance of Fas activation in nonpulmonary/shock-induced ALI and the feasibility of intrapulmonary administration of anti-apoptotic siRNA in vivo.     

Growth, morbidity, and mortality in a cohort of institutionalized HIV-1-infected African children

OBJECTIVE: As a result of the HIV epidemic in Africa, much debate exists on whether institutionalized compared with community-based care provides optimum management of infected children. Previous reports calculated 89% mortality by age 3 years among outpatients in Malawi. No similar data are available for infected children in institutionalized care. We characterized patterns of morbidity and mortality among HIV-1-infected children residing at an orphanage in Nairobi. METHODS: Medical records for 174 children followed over 5 years were reviewed. Mortality was analyzed by Kaplan-Meier methods with adjustment to account for survival in the community before admission. Anthropometric indices were calculated to include mean z scores for weight for length and length for age. Low indices reflected wasting and stunting. Opportunistic infections were documented. RESULTS: Of 174 children, 64 had died. Survival was 70% at age 3 years. Morbidity included recurrent respiratory tract infections, gastroenteritis, parotitis, and lymphoid interstitial pneumonitis. No new cases of tuberculosis disease were noted after admission. Mean z scores for length for age suggested overall stunting (z = -1.65). Wasting was not observed (z = -0.39). CONCLUSION: The optimal form of care for HIV-infected children in resource-poor settings may be the development of similar homes. Absence of tuberculosis disease in long-standing residents may have contributed to improved survival. Stunting in the absence of wasting implied that growth was compromised by opportunistic infections and other cofactors.     

<Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> Ats1p interacts with Nap1p,a cytoplasmic protein that controls bud morphogenesis

Saccharomyces cerevisiae ATS1 (-tubulin suppressor 1) was originally identified as a high-copy suppressor of class two -tubulin mutations and was proposed to have a regulatory role in coordinating the microtubule state with the cell cycle. Here, we show that Ats1p interacts with Nap1p, a cytoplasmic protein that regulates the activity of the Cdc28p/Clb2p complex. Loss of Nap1p results in a delayed switch from polar to isotropic bud growth. The delayed switch results in elongated buds. Nap1p and Ats1p interact in two-hybrid and co-immunoprecipitation assays. Both nap1 and ats1 cells have a Clb2p-dependent elongated bud morphology. Deletion of ATS1 partially suppresses the elongated bud morphology and benomyl resistance of nap1 mutants. Our results suggest Ats1p might regulate coordination of the microtubule state with the cell cycle through an interaction with Nap1p.Communicated by S. Hohmann     

Health-related quality-of-life measures for children with asthma: reliability and validity of the Children's Health Survey for Asthma and the Pediatric Quality of Life Inventory 3.0 Asthma Module.

BACKGROUND: Economically disadvantaged African American youth are especially vulnerable to the effects of pediatric asthma and are at increased risk for difficulties in daily functioning. Measures of health-related quality of life (HRQoL) yield important information regarding the impact of pediatric chronic illness on daily functioning. It is essential to develop and validate measures of HRQoL to detect the impact of asthma on this vulnerable population. OBJECTIVE: To examine the psychometric properties of 2 asthma-specific measures of pediatric HRQoL in a sample of economically disadvantaged African American children diagnosed as having asthma. METHODS: One hundred twenty-seven caregivers completed questionnaires regarding their child's HRQoL, asthma symptoms, health care utilization, and school absences and regarding caregiver emotional distress. The severity of the child's asthma was measured via spirometry. RESULTS: The Children's Health Survey for Asthma and the Pediatric Quality of Life Inventory 3.0 Asthma Module demonstrated adequate internal consistency reliability and validity for the present sample. Lower HRQoL was associated with poorer adherence and more health care utilization, asthma symptom days, school absences, and caregiver distress. Only the Children's Health Survey for Asthma was significantly associated with severity, when defined as airway obstruction. CONCLUSIONS: This study supports the psychometric equivalence of 2 condition-specific measures of HRQoL in a population at high risk for asthma and asthma-related problems. The utility of each measure will depend on the needs of the researcher or physician. Both measures can inform the treatment course, help identify and address barriers to treatment adherence, and inform treatment interventions.