Association of secondhand smoke exposure with pediatric invasive bacterial disease and bacterial carriage: a systematic review and meta-analysis

Background

A number of epidemiologic studies have observed an association between secondhand smoke (SHS) exposure and pediatric invasive bacterial disease (IBD) but the evidence has not been systematically reviewed. We carried out a systematic review and meta-analysis of SHS exposure and two outcomes, IBD and pharyngeal carriage of bacteria, for Neisseria meningitidis (N. meningitidis), Haemophilus influenzae type B (Hib), and Streptococcus pneumoniae (S. pneumoniae).

Methods and Findings

Two independent reviewers searched Medline, EMBASE, and selected other databases, and screened articles for inclusion and exclusion criteria. We identified 30 case-control studies on SHS and IBD, and 12 cross-sectional studies on SHS and bacterial carriage. Weighted summary odd ratios (ORs) were calculated for each outcome and for studies with specific design and quality characteristics. Tests for heterogeneity and publication bias were performed. Compared with those unexposed to SHS, summary OR for SHS exposure was 2.02 (95% confidence interval [CI] 1.52–2.69) for invasive meningococcal disease, 1.21 (95% CI 0.69–2.14) for invasive pneumococcal disease, and 1.22 (95% CI 0.93–1.62) for invasive Hib disease. For pharyngeal carriage, summary OR was 1.68 (95% CI, 1.19–2.36) for N. meningitidis, 1.66 (95% CI 1.33–2.07) for S. pneumoniae, and 0.96 (95% CI 0.48–1.95) for Hib. The association between SHS exposure and invasive meningococcal and Hib diseases was consistent regardless of outcome definitions, age groups, study designs, and publication year. The effect estimates were larger in studies among children younger than 6 years of age for all three IBDs, and in studies with the more rigorous laboratory-confirmed diagnosis for invasive meningococcal disease (summary OR 3.24; 95% CI 1.72–6.13).

Conclusions

When considered together with evidence from direct smoking and biological mechanisms, our systematic review and meta-analysis indicates that SHS exposure may be associated with invasive meningococcal disease. The epidemiologic evidence is currently insufficient to show an association between SHS and invasive Hib disease or pneumococcal disease. Because the burden of IBD is highest in developing countries where SHS is increasing, there is a need for high-quality studies to confirm these results, and for interventions to reduce exposure of children to SHS. Please see later in the article for the Editors'' Summary     

Developmental changes in the fatty acids of rat uterus and the influence of dietary essential fatty acids.

The effect of age on uterine fatty acid composition was studied in rats fed diets of differing fatty acid composition. Uteri of newly weaned 23-day rats had a higher fatty acid content and a higher proportion of short-chain (less than or equal to C18) fatty acids. Higher incorporation of C less than or equal to 18 fatty acids into neutral lipid (NL) and phospholipid (PL) of young 42-day rats compared with adult 240-day rats was detected. Uterine NL incorporated predominantly C less than or equal to 18 fatty acids which may be an important metabolic energy store in developing uterine tissue. Incorporation of C less than or equal to 18 fatty acids by uterine PL and NL was relatively unselective. In contrast, there was selective retention of arachidonic acid (AA) and docosahexanoic acid (DHA) throughout uterine development. An effect of dietary EFA on uterine n-3 and n-6 EFA was detected in each age group. There was marked retention of uterine AA when dietary supplies of n-6 EFA were low, but the total AA, eicosapentaenoic acid (EPA) and DHA in uterine PL remained constant in the three diet groups, and a constant content of AA, EPA and DHA was maintained throughout uterine development, regardless of diet. The degree of n-3 substitution achieved in this study inhibited uterine release of PG and parturition in adult rats.     

17beta-Estradiol responsiveness of MCF-7 laboratory strains is dependent on an autocrine signal activating the IGF type I receptor

BACKGROUND: Human MCF-7 cells have been studied extensively as a model for breast cancer cell growth. Many reports have established that serum-starved MCF-7 cells can be induced to proliferate upon the sole addition of 17beta-estradiol (E2). However, the extent of the mitogenic response to E2 varies in different MCF-7 strains and may even be absent. In this study we compared the E2-sensitivity of three MCF-7 laboratory strains. RESULTS: The MCF-7S line is non-responsive to E2, the MCF-7 ATCC has an intermediate response to E2, while the MCF-7 NKI is highly E2-sensitive, although the levels and activities of the estrogen receptor (ER) are not significantly different. Both suramin and IGF type I receptor blocking antibodies are able to inhibit the mitogenic response to E2-treatment in MCF-7 ATCC and MCF-7 NKI cells. From this we conclude that E2-induced proliferation is dependent on IGF type I receptor activation in all three MCF-7 strains. CONCLUSIONS: The results presented in this article suggest that E2-responsiveness of MCF-7 cells is dependent on the secretion of an autocrine factor activating the IGF-IR. All three strains of MCF-7 breast cancer cells investigated do not respond to E2 if the IGF-RI-pathway is blocked. Generally, breast cancer therapy is targeted at inhibiting estrogen action. This study suggests that inhibition of IGF-action in combination with anti-estrogen-treatment may provide a more effective way in treatment or even prevention of breast cancer.     

Comparative characteristics of nests of Vespula germanica (F.) and Vespula vulgaris (L.) (Hymenoptera: Vespinae) from Christchurch City,New Zealand

Abstract

From July 1987 to June 1989, 141 nests and 365 nests, respectively, of the adventive social vespines the German wasp, Vespula germanica (F.), and the common wasp V. vulgaris (L.), from the City of Christchurch, New Zealand, were evaluated for seven major characteristics.

There were few, if any, differences in nest sites, and from spring to early summer in nest traffic, nest size, and numbers of combs. However, Getman wasps showed no preference for direction of nest entrances, while common wasp nests were more numerous in areas most exposed to the morning sun. Some Getman wasp nests survived the winter and began producing new worker cells by late June, but all common wasp nests died by June. Because common wasp nests have been reported surviving the winter in beech forest, which produces honey dew, and honey dew is not available in Christchurch City, common wasp nest survival over winter may be more dependent upon carbohydrates and/or prey dependent upon carbohydrates than the survival of German wasp nests. The presence of large, expanding wasp nests from early spring must impose localised predation pressures virtually unknown in the Northern Hemisphere where overwintering nests are rare. Wasp population dynamics, and impacts of wasps on fauna, are likely to vary between different geographical areas of New Zealand, but as targets for biological control, the two wasp species can generally be considered to be quite similar.     

Genomic organization and characterization of mouse SAP, the gene that is altered in X-linked lymphoproliferative disease

X-linked lymphoproliferative (XLP) disease is a fatal immunological disorder that renders the immune system unable to respond effectively to Epstein-Barr virus (EBV) infection. The gene that encodes a protein termed SAP or SH2D1A is either deleted or mutated in XLP patients, resulting in uncontrolled B- and T-cell proliferation upon EBV infection. Here, we report the cloning and characterization of the mouse SAP gene. It is localized on the mouse X chromosome and comprises four exons spanning approximately 25 kb. Its expression appears to be restricted to T lymphocytes. Whereas a high level of SAP expression is observed in Thl cells, only small amounts are detectable in Th2 cells. Moreover, SAP expression is down-regulated upon in vitro activation of T cells, including CD4+, CD8+ single-positive T cells, and Thl and Th2 cells. This study provides valuable information for in-depth genetic and biochemical analysis of the function of SAP in the immune system.     

Redescription and palaeobiology of Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate of Germany

Abstract: Palaeoscorpius devonicus Lehmann, 1944 is known from only a single specimen, found in the Eschenbach Pit near Bundenbach in the Lower Devonian Hunsrück Slate of Germany. It is a key fossil, having been interpreted both as the most basal member of the Scorpiones and as one of the order’s most likely candidates for an aquatic mode of life. Prepared both ventrally and dorsally, some aspects of its morphology remain problematic. Here, with the aid of new techniques, including computed tomography, we present a re‐investigation of this scorpion’s anatomy and a new reconstruction, with a particular focus on the species’ original habitat. On the basis of the environmental interpretation of the Hunsrück Slate and the completeness of the specimen, previous authors concluded that P. devonicus was marine, but none offered convincing morphological evidence. Recent studies of the deposit’s environment suggest that the Hunsrück Sea was part of an intrashelf basin, relatively close to the coastline, and fossils of land plants show that terrestrial wash‐in occasionally occurred. Our revised interpretation of the fossil’s morphology demonstrates that the scorpion was most probably terrestrial. Internal mesosomal organs are interpreted as book lungs, but other terrestrial adaptations are lacking. The absence of both coxapophyses and gnathobases makes determining the scorpion’s feeding mechanism difficult. Interpreting the scorpion’s character states within a phylogenetic framework, especially the possible presence of book lungs, implies either that the plesiomorphic position of P. devonicus is no longer supported or that the development of book lungs had already taken place early in the scorpion lineage.     

Resolution of Der p1-induced allergic airway inflammation is dependent on CD4+CD25+Foxp3+ regulatory cells

Allergic airway inflammation (AAI) is characterized by airway hyperreactivity, eosinophilia, goblet cell hyperplasia, and elevated serum IgE, however, it is unclear what mediates natural resolution after cessation of allergen exposure. This is important because the outcome of subsequent allergen challenge may depend on the concurrent inflammatory milieu of the lung. Using a murine AAI model, we demonstrate that after exposure to a defined natural protein allergen, Der p1, the response in lungs and draining mediastinal lymph nodes (dMLN) peaks between 4 and 6 days then declines until resolution by 21 days. Der p1-specific serum IgE follows the same pattern while IgG1 continues to increase. Resolution of AAI is mediated by CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs), which appear in lungs and dMLN following airway challenge. Treg depletion exacerbated lung eosinophilia, increased dMLN IL-5 and IL-13 but not IL-10 secretion, and increased allergic Ab responses. Most convincingly, transfer of CD4(+)CD25(+)Foxp3(+) T cells from Ag naive mice (natural Tregs) abolished AAI, decreased dMLN IL-5 and IL-13 secretion, increased dMLN IL-10 secretion, abolished IgE, and decreased IgG1 Abs. Blocking IL-10 receptor function in vivo did not block the anti-inflammatory function of transferred natural Tregs but did restore dMLN IL-5 and IL-13 secretion. Thus natural Tregs can control AAI in an IL-10 independent manner.