Marital status, living arrangement and mortality: does the association vary by gender?

Men appear to benefit more from being married than women with respect to mortality in middle age. However, there is some uncertainty about gender differences in mortality risks in older individuals, widowed, divorced and single individuals and about the impact of living arrangements.

Screening of Swiss hot spring resorts for potentially pathogenic free-living amoebae

Free-living amoebae (FLA) belonging to Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Sappinia pedata are known to cause infections in humans and animals leading to severe brain pathologies. Worldwide, warm aquatic environments have been found to be suitable habitats for pathogenic FLA. The present study reports on screening for potentially pathogenic FLA in four hot spring resorts in Switzerland. Water samples were taken from water filtration units and from the pools, respectively. Amoebae isolated from samples taken during, or before, the filtration process were demonstrated to be morphologically and phylogenetically related to Stenoamoeba sp., Hartmannella vermiformis, Echinamoeba exundans, and Acanthamoeba healyi. With regard to the swimming pools, FLA were isolated only in one resort, and the isolate was identified as non-pathogenic and as related to E. exundans. Further investigations showed that the isolates morphologically and phylogenetically related to A. healyi displayed a pronounced thermotolerance, and exhibited a marked in vitro cytotoxicity upon 5-day exposure to murine L929 fibroblasts. Experimental intranasal infection of Rag2-immunodeficient mice with these isolates led to severe brain pathologies, and viable trophozoites were isolated from the nasal mucosa, brain tissue, and lungs post mortem. In summary, isolates related to A. healyi were suggestive of being potentially pathogenic to immunocompromised persons. However, the presence of these isolates was limited to the filtration units, and an effective threat for health can therefore be excluded.

Probing the Mechanical Properties of Magnetosome Chains in Living Magnetotactic Bacteria

The mechanical properties of cytoskeletal networks are intimately involved in determining how forces and cellular processes are generated, directed, and transmitted in living cells. However, determining the mechanical properties of subcellular molecular complexes in vivo has proven to be difficult. Here, we combine in vivo measurements by optical microscopy, X-ray diffraction, and transmission electron microscopy with theoretical modeling to decipher the mechanical properties of the magnetosome chain system encountered in magnetotactic bacteria. We exploit the magnetic properties of the endogenous intracellular nanoparticles to apply a force on the filament-connector pair involved in the backbone formation and stabilization. We show that the magnetosome chain can be broken by the application of external field strength higher than 30 mT and suggest that this originates from the rupture of the magnetosome connector MamJ. In addition, we calculate that the biological determinants can withstand in vivo a force of 25 pN. This quantitative understanding provides insights for the design of functional materials such as actuators and sensors using cellular components.

Determinants of hepatitis A vaccine immunity in a cohort of human immunodeficiency virus-infected children living in Switzerland

Vaccination in HIV-infected children is often less effective than in healthy children. The goal of this study was to assess vaccine responses to hepatitis A virus (HAV) in HIV-infected children. Children of the Swiss Mother and Child HIV Cohort Study (MoCHiV) were enrolled prospectively. Recommendations for initial, catch-up, and additional HAV immunizations were based upon baseline antibody concentrations and vaccine history. HAV IgG was assessed by enzyme-linked immunosorbent assay (ELISA) with a protective cutoff value defined as ≥10 mIU/ml. Eighty-seven patients were included (median age, 11 years; range, 3.4 to 21.2 years). Forty-two patients were seropositive (48.3%) for HAV. Among 45 (51.7%) seronegative patients, 36 had not received any HAV vaccine dose and were considered naïve. Vaccine responses were assessed after the first dose in 29/35 naïve patients and after the second dose in 33/39 children (25 initially naïve patients, 4 seronegative patients, and 4 seropositive patients that had already received 1 dose of vaccine). Seroconversion was 86% after 1 dose and 97% after 2 doses, with a geometric mean concentration of 962 mIU/ml after the second dose. A baseline CD4(+) T cell count below 750 cells/μl significantly reduced the post-2nd-dose response (P = 0.005). Despite a high rate of seroconversion, patients with CD4(+) T cell counts of <750/μl had lower anti-HAV antibody concentrations. This may translate into a shorter protection time. Hence, monitoring humoral immunity may be necessary to provide supplementary doses as needed.

Regional Differences in Living Standards in Eastern European Countries - Changes During the Transition

This research aimed to discover how differences in living standards between regional units changed during the period of transformation from 1990 to 1995 in Poland, the Slovak Republic, the Czech Republic and Hungary. The standard of living was measured by the so-called Living Standard Index (LSI), a composite taxonomic measure. Fixed reference points make it possible to compare the standard of living in regional administrative units and to study its dynamics. The analysis was country-specific, since the lists of variable were not fully identical for all the countries studied. The main tools used were LSI variability measures (mainly variance and standard deviation). By identifying trend patterns in the characteristics of LSIs, it was possible to compare the different countries. It was found that * differences in living standards between regional units have been decreasing during the transformation in Poland and in the Czech Republic. In the latter this process is slow and smooth, while in Poland there was a relatively sharp decline which then stopped entirely in 1994 * the only country with increasing differences between regions is Hungary and these differences are growing at a constant rate * the lowest level of regional differences in the LSI was found in Poland, followed by the Slovak Republic and the Czech Republic * the regional differences in Hungary are almost twice as high as in the Czech Republic

Synthesis and two-photon photolysis of 6-(ortho-nitroveratryl)-caged IP3 in living cells

The synthesis of a photolabile derivative of inositol-1,4,5-trisphosphate (IP3) is described. This new caged second messenger (6-ortho-nitroveratryl)-IP3 (6-NV-IP3) has an extinction coefficient of 5000 M(-1) cm(-1) at 350 nm, and a quantum yield of photolysis of 0.12. Therefore, 6-NV-IP3 is photolyzed with UV light about three times more efficiently than the widely used P(4(5))-1-(2-nitrophenyl)ethyl-caged IP3 (NPE-IP3). 6-NV-IP3 has a two-photon cross-section of about 0.035 GM at 730 nm. This absorbance is sufficiently large for effective two-photon excitation in living cells at modest power levels. Using near-IR light (5 mW, 710 nm, 80 MHz, pulse-width 70 fs), we produced focal bursts of IP3 in HeLa cells, as revealed by laser-scanning confocal imaging of intracellular Ca2+ concentrations. Therefore, 6-NV-IP3 can be used for efficient, subcellular photorelease of IP3, not only in cultured cells but also, potentially, in vivo. It is in the latter situation that two-photon photolysis should reveal its true forte.

The nitrodibenzofuran chromophore: a new caging group for ultra-efficient photolysis in living cells

Photochemical uncaging of bio-active molecules was introduced in 1977, but since then, there has been no substantial improvement in the properties of generic caging chromophores. We have developed a new chromophore, nitrodibenzofuran (NDBF) for ultra-efficient uncaging of second messengers inside cells. Photolysis of a NDBF derivative of EGTA (caged calcium) is about 16-160 times more efficient than photolysis of the most widely used caged compounds (the quantum yield of photolysis is 0.7 and the extinction coefficient is 18,400 M(-1) cm(-1)). Ultraviolet (UV)-laser photolysis of NDBF-EGTA:Ca(2+) rapidly released Ca(2+) (rate of 20,000 s(-1)) and initiated contraction of skinned guinea pig cardiac muscle. NDBF-EGTA has a two-photon cross-section of approximately 0.6 GM and two-photon photolysis induced localized Ca(2+)-induced Ca(2+) release from the sarcoplasmic recticulum of intact cardiac myocytes. Thus, the NDBF chromophore has great promise as a generic and photochemically efficient protecting group for both one- and two-photon uncaging in living cells.

Health risk appraisal in older people 1: are older people living alone an "at-risk" group?

BACKGROUND: In the UK, population screening for unmet need has failed to improve the health of older people. Attention is turning to interventions targeted at 'at-risk' groups. Living alone in later life is seen as a potential health risk, and older people living alone are thought to be an at-risk group worthy of further intervention. AIM: To explore the clinical significance of living alone and the epidemiology of lone status as an at-risk category, by investigating associations between lone status and health behaviours, health status, and service use, in non-disabled older people. Design of study: Secondary analysis of baseline data from a randomised controlled trial of health risk appraisal in older people. SETTING: Four group practices in suburban London. METHOD: Sixty per cent of 2641 community-dwelling non-disabled people aged 65 years and over registered at a practice agreed to participate in the study; 84% of these returned completed questionnaires. A third of this group, (n = 860, 33.1%) lived alone and two-thirds (n = 1741, 66.9%) lived with someone else. RESULTS: Those living alone were more likely to report fair or poor health, poor vision, difficulties in instrumental and basic activities of daily living, worse memory and mood, lower physical activity, poorer diet, worsening function, risk of social isolation, hazardous alcohol use, having no emergency carer, and multiple falls in the previous 12 months. After adjustment for age, sex, income, and educational attainment, living alone remained associated with multiple falls, functional impairment, poor diet, smoking status, risk of social isolation, and three self-reported chronic conditions: arthritis and/or rheumatism, glaucoma, and cataracts. CONCLUSION: Clinicians working with independently-living older people living alone should anticipate higher levels of disease and disability in these patients, and higher health and social risks, much of which will be due to older age, lower educational status, and female sex. Living alone itself appears to be associated with higher risks of falling, and constellations of pathologies, including visual loss and joint disorders. Targeted population screening using lone status may be useful in identifying older individuals at high risk of falling.

Asthma in young south Asian women living in the United Kingdom: the importance of early life

BACKGROUND: Studies of immigrants suggest that the environment during fetal life and duration of residence in the host country might influence the development of asthma. Little is known about the importance of the timing of the exposure in the host country and whether migrants might be especially vulnerable in certain age windows. OBJECTIVE: We compared the reported prevalence of asthma between young white and south Asian women in the United Kingdom, and investigated associations with country of birth and age at immigration. METHODS: A questionnaire on atopic disorders was posted to 2380 south Asian and 5796 white young mothers randomly sampled in Leicestershire. Data on ethnicity were also available from maternity records. Data were analysed using multivariable logistic regression and a propensity score approach. Results The reported prevalence of asthma was 10.9% in south Asian and 21.8% in white women. South Asian women who migrated to the United Kingdom aged 5 years or older reported less asthma (6.5%) than those born in the United Kingdom or who migrated before age 5 (16.0%), with an adjusted odds ratio of 0.38 [95% Confidence Interval 0.23-0.64, P<0.001]. For those who migrated aged over 5 years, the prevalence did not alter with the duration of residence in the United Kingdom. Current exposure to common environmental risk factors had relatively little effect on prevalence estimates. CONCLUSION: These data from a large population-based study support the hypothesis that early life environmental factors influence the risk of adult asthma.