Small-for-gestational-age preterm-born infants already have lower bone mass during early infancy

BackgroundIn preterm-born infants, low birth weight and diminished bone accretion deteriorate peak bone mass. Whether low birth weight is already associated with decreased bone mass during infancy is unknown.ObjectiveTo study the effect of birth weight on bone accretion between term age (40 weeks postmenstrual age) and six months post-term in preterm-born infants.DesignIn 139 preterm-born infants (51% male, gestational age 30.3 ± 1.5 weeks, birth weight 1341 ± 288 g) weight and whole-body bone mineral content (BMC, gram) were measured at term age and six months post-term. At birth, infants were small-for-gestational-age (SGA, n = 33, weight and/or length < ? 2 SDS) or appropriate-for-gestational-age (AGA, n = 98, weight and length ≥ ? 2 SDS).ResultsAt term age and six months post-term, BMC adjusted for gender and gestational age was lower in SGA than AGA infants (term age: 38.1 ± 9.5 versus 48.6 ± 10.1 g, β = ? 0.26, 95% CI ? 0.37; ? 0.16, p < 0.001; six months: 130.1 ± 25.7 versus 145.4 ± 22.9 g, β = ? 0.16, 95% CI ? 0.25; ? 0.08, p < 0.001). At six months post-term, BMC remained lower in SGA infants after adjustment for actual weight and length. Between term age and six months post-term, BMC gain adjusted for gender and gestational age was lower in SGA than AGA infants (91.7 ± 22.8 versus 98.2 ± 20.7 g; β = ? 0.12, 95% CI ? 0.24; ? 0.003, p = 0.044). BMC gain remained lower in SGA infants after adjustment for weight and length gain.ConclusionThe first six months post-term, SGA preterms have lower bone accretion, independent of body size, suggesting that prenatal conditions for bone accretion cannot be replicated postnatally.     

Glucosamine decreases expression of anabolic and catabolic genes in human osteoarthritic cartilage explants

OBJECTIVE: To investigate the effect of glucosamine (GlcN) in a human osteoarthritic explant model on expression of genes involved in anabolic and catabolic activities of chondrocytes. METHODS: Human osteoarthritic explants, obtained during knee arthroplasty surgery, were pre-cultured (3 days) and treated with glucosamine-hydrochloride (GlcN-HCl) or glucosamine-3-sulphate (GlcN-S) at 0.5mM and 5mM (4 days). RNA was isolated from the explants and real time RT-PCR was performed. Additionally, total matrix metalloproteinase (MMP) activity was measured in culture medium. RESULTS: Addition of 5mM GlcN led to significant down-regulation of aggrecan (2.65-7.73-fold) and collagen type II (7.75-22.17-fold) gene expression, indicating inhibited anabolic activity. Considering catabolic activities, 5mM GlcN significantly down-regulated aggrecanase-1 and MMP3 and 5mM GlcN-S additionally down-regulated aggrecanase-2 and tissue inhibitor of MMP gene expression significantly. Gene expression was not significantly altered by 0.5mM GlcN. Total MMP activity in culture medium was only significantly reduced after addition of 5mM GlcN-HCl. CONCLUSION: The effects of GlcN on gene expression in a human osteoarthritic explant model suggest that enzymatic breakdown of the extra-cellular matrix might be reduced by the addition of 5mM GlcN. Additionally, restoration of already damaged cartilage is not to be expected, because gene expression of anabolic genes is also down-regulated. We suggest that chondroprotective properties of GlcN in vivo may be based on inhibiting further degradation due to catabolic activities, rather than on the ability to rebuild cartilage.     

Conservation of biological properties of the CD40 ligand, CD154 in a non-mammalian vertebrate

Signals delivered by the CD40 ligand, CD154, have crucial roles in immune responses in mammals, being required for development of germinal centres, maturation of T-dependent antibody responses, and generation of B-cell memory. To determine whether these functions were conserved in a non-mammalian species, a putative chicken CD 154 cDNA was used to make an oligomeric fusion protein, and to raise monoclonal antibodies. The antibodies detected surface expression on activated T-cells. The fusion protein detected expression of a receptor on B-cells, thrombocytes and macrophages. Biological effects of the fusion protein included induction of NO synthesis in a macrophage cell line, enhancement of splenic B-cell survival, and induction of apoptosis in a bursal lymphoma cell line. These observations demonstrated substantial functional equivalence with mammalian CD 154 and thus provided evidence for the early evolutionary emergence of the set of functions associated with this molecule, and its central role in the vertebrate immune system.     

Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro

The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeated exposure. The influence of repeated and single exposure to representative biocidal active substances on the skin barrier was investigated in vitro. The biocidal active substances selected were alkyldimethylbenzylammonium chloride (ADBAC), boric acid, deltamethrin, dimethyldidecylammonium chloride (DDAC), formaldehyde, permethrin, piperonyl butoxide, sodium bromide, and tebuconazole. Of these nine compounds, only the quaternary ammonium chlorides ADBAC and DDAC had a clear and consistent influence on skin permeability of the marker compounds tritiated water and [(14)C]propoxur. For these compounds, repeated exposure increased skin permeability more than single exposure. At high concentrations the difference between single and repeated exposure was quantitatively significant: repeated exposure to 300 mg/L ADBAC increased skin permeability two to threefold in comparison to single exposure. Therefore, single and repeated exposure to specific biocidal products may significantly increase skin permeability, especially when used undiluted.     

Disease control in primary health care: a historical perspective

The effectiveness of disease control by mobile teams decreased when countries became independent. Early case-finding and continuity of care require permanently accessible health care facilities where rationalization by professionals and participation of the users are well balanced. The Primary Health Care concept, a plea for this equilibrium, has been discredited by different types of misapplication. Correctly functioning and accessible first line health services, completed by a referral level, are a precondition for effective participation of the users. Where 'ideal health districts' cannot be realized, a form of steady exchanges between generalists and the specialists of the referral level has lead to diverse 'functional districts'.     

Syndromic surveillance in the Netherlands for the early detection of West Nile virus epidemics

West Nile virus (WNV) is an arthropod-borne flavivirus that is endemic in Africa, Europe, and Eastern Asia. The recent introduction and rapid dissemination of the virus in the United States as well as an increase in WNV outbreaks in Europe, has raised concerns for its spread in Europe. A surveillance system was developed to allow timely detection of an introduction of WNV infections in The Netherlands. This program focuses on cases presenting with neurological disease and includes the monitoring of hospital discharge diagnoses, trends in cerebrospinal fluid (CSF) diagnostic requests, laboratory testing of CSF, and monitoring of neurological disease in horses. Retrospective data from the hospital discharge records showed yearly peaks of unexplained meningitis and (meningo)encephalitis in the summer. A total of 781 CSF samples from humans and 71 serum and/or CSF samples from horses presenting with neurological disease of suspected viral etiology tested negative for the presence of specific antibodies to WNV. With a coverage rate of 59% in 2003, the probability that a cluster of five WNV cases presenting with neurological symptoms would have been detected was 99%. We conclude that, from 1999 to 2004, no evidence of WNV infection could be found in either humans or horses in The Netherlands.