Cohort Differences in the Associations of Selected Candidate Genes With Risk of All-Cause Mortality at Advanced Ages.

Considerable efforts have been made to identify the genetic basis of human longevity, with only limited progress. One important drawback of current genetic studies is the limited knowledge of gene-environment interaction. Using 2 cohorts of long-lived individuals born in 1905 and 1915 in Denmark, we performed survival analysis to estimate risk of mortality for major candidate genes of aging and longevity and their cohort effects.

Analyzing age-specific genetic effects on human extreme age survival in cohort-based longitudinal studies.

The analysis of age-specific genetic effects on human survival over extreme ages is confronted with a deceleration pattern in mortality that deviates from traditional survival models and sparse genetic data available. As human late life is a distinct phase of life history, exploring the genetic effects on extreme age survival can be of special interest to evolutionary biology and health science. We introduce a non-parametric survival analysis approach that combines population survival information with individual genotype data in assessing the genetic effects in cohort-based longitudinal studies.

Trends in rates of natural conceptions among Danish women born during 1960-1984.

Study Question: The aim of the study was to analyse trends in the rate of natural conceptions (RNC) among birth cohorts of women born during the period 1960-1984.

Summary Answer: In this nationwide study of Danish-born female cohorts born during the period 1960-1984, we found a gradual decline in the RNC with successive birth cohorts.

What Is Known Already: Our results confirm the findings from a previous study on trends in RNC among native Danish women.

Human longevity and variation in GH/IGF-1/insulin signaling, DNA damage signaling and repair and pro/antioxidant pathway genes: cross sectional and longitudinal studies.

Here we explore association with human longevity of common genetic variation in three major candidate pathways: GH/IGF-1/insulin signaling, DNA damage signaling and repair and pro/antioxidants by investigating 1273 tagging SNPs in 148 genes composing these pathways. In a case-control study of 1089 oldest-old (age 92-93) and 736 middle-aged Danes we found 1 pro/antioxidant SNP (rs1002149 (GSR)), 5 GH/IGF-1/INS SNPs (rs1207362 (KL), rs2267723 (GHRHR), rs3842755 (INS), rs572169 (GHSR), rs9456497 (IGF2R)) and 5 DNA repair SNPs (rs11571461 (RAD52), rs13251813 (WRN), rs1805329 (RAD23B), rs2953983 (POLB), rs3211994 (NTLH1)) to be associated with longevity after correction for multiple testing. In a longitudinal study with 11 years of follow-up on survival in the oldest-old Danes we found 2 pro/antioxidant SNPs (rs10047589 (TNXRD1), rs207444 (XDH)), 1 GH/IGF-1/INS SNP (rs26802 (GHRL)) and 3 DNA repair SNPs (rs13320360 (MLH1), rs2509049 (H2AFX) and rs705649 (XRCC5)) to be associated with mortality in late life after correction for multiple testing.

Evidence from case-control and longitudinal studies supports associations of genetic variation in APOE, CETP, and IL6 with human longevity.

In this study, we investigated 102 single-nucleotide polymorphisms (SNPs) covering the common genetic variation in 16 genes recurrently regarded as candidates for human longevity: APOE; ACE; CETP; HFE; IL6; IL6R; MTHFR; TGFB1; APOA4; APOC3; SIRTs 1, 3, 6; and HSPAs 1A, 1L, 14. In a case-control study of 1,089 oldest-old (ages 92-93) and 736 middle-aged Danes, the minor allele frequency (MAF) of rs769449 (APOE) was significantly decreased in the oldest-old, while the MAF of rs9923854 (CETP) was significantly enriched. These effects were supported when investigating 1,613 oldest-old (ages 95-110) and 1,104 middle-aged Germans.

Bioinspired principles for large-scale networked sensor systems: an overview.

Biology has often been used as a source of inspiration in computer science and engineering. Bioinspired principles have found their way into network node design and research due to the appealing analogies between biological systems and large networks of small sensors. This paper provides an overview of bioinspired principles and methods such as swarm intelligence, natural time synchronization, artificial immune system and intercellular information exchange applicable for sensor network design.

Risk of breast cancer in families with cleft lip and palate.

Purpose: To test whether female subjects in families with cleft lip and/or palate (CL/P) have an increased risk of breast cancer.

Methods: By using the Danish Facial Cleft Registry, we identified female subjects with CL/P, mothers of children with CL/P, and sisters to CL/P cases for the Danish birth cohorts 1911-1975. These subjects were compared with a 5% random sample of these cohorts regarding the incidence and age of onset for breast cancer registered in the Danish Hospital Discharge Register 1977-2005.

Sex Differences in Medication and Primary Healthcare Use before and after Spousal Bereavement at Older Ages in Denmark: Nationwide Register Study of over 6000 Bereavements.

Background. The study aimed to examine sex differences in healthcare use before and after widowhood to investigate whether reduced healthcare use among widowers compared with widows may partially explain excess mortality and more adverse health outcomes among men than women after spousal loss. Methods.

Increased effect of the ApoE gene on survival at advanced age in healthy and long-lived Danes: two nationwide cohort studies.

Studies of Nordic twins suggest an increased genetic influence on mortality with age. Contrary to this, the heterogeneity hypothesis predicts that the mortality of individuals carrying a 'frail' or 'risky' genotype in a population will approach that of noncarriers with age because of selection pressure. The ApoE ε4 allele is associated with an increased mortality risk, and its effect has been suggested to decrease with age.

Is the relationship between BMI and mortality increasingly U-shaped with advancing age? A 10-year follow-up of persons aged 70-95 years.

Background: In the call for papers (Alley DE, Ferrucci L, Barbagallo M, Studenski SA, Harris TB. A research agenda: the changing relationship between body weight and health in aging. J Gerontol A Biol Sci Med Sci.

Good semen quality and life expectancy: a cohort study of 43,277 men.

Fertility status may predict later mortality, but no studies have examined the effect of semen quality on subsequent mortality. Men referred to the Copenhagen Sperm Analysis Laboratory by general practitioners and urologists from 1963 to 2001 were, through a unique personal identification number, linked to the Danish central registers that hold information on all cases of cancer, causes of death, and number of children in the Danish population. The men were followed until December 31, 2001, death, or censoring, whichever occurred first, and the total mortality and cause-specific mortality of the cohort were compared with those of all age-standardized Danish men or according to semen characteristics.

Sex differential in mortality trends of old-aged Danes: a nation wide study of age, period and cohort effects.

Objective: Over the last half century the mortality rates in Denmark for females above age 80 have declined dramatically whereas the decline for males have been modest, resulting in a change in sex-ratio for centenarians from 2 to 5. Here we investigate whether this mortality pattern is mainly explained by period effects, cohort effects or both. This can provide clues for where to search for causes behind the changes in sex differential in mortality seen in many Western countries during the last decades.

Cellular telephone use and cancer risk: update of a nationwide Danish cohort.

Background: The widespread use of cellular telephones has heightened concerns about possible adverse health effects. The objective of this study was to investigate cancer risk among Danish cellular telephone users who were followed for up to 21 years.

Methods: This study is an extended follow-up of a large nationwide cohort of 420,095 persons whose first cellular telephone subscription was between 1982 and 1995 and who were followed through 2002 for cancer incidence.

Causes of death behind low life expectancy of Danish women.

Aims: The authors examined causes of death contributing to the relatively high mortality of Danish women born 1915-45, and evaluated the impact of smoking related causes of death.

Methods: Age-period-cohort analysis of mortality of Danish women aged 40-89 in 1960-98. Estimate of the negative curvature in parabola patterns for 50 causes of death.

Strained silicon as a new electro-optic material.

For decades, silicon has been the material of choice for mass fabrication of electronics. This is in contrast to photonics, where passive optical components in silicon have only recently been realized. The slow progress within silicon optoelectronics, where electronic and optical functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon.

Trends in testicular cancer incidence in the Nordic countries, focusing on the recent decrease in Denmark.

Testicular cancer is the most frequent malignancy among young men, and there have been steady increases in its incidence in most western countries for many decades. Recently, a decrease was seen in some countries, including Denmark. Here, we report recent trends in testicular cancer incidence in the Nordic countries.

Planar glass devices for efficient periodic poling.

We demonstrate that frequency-converting devices of high quality can be realised with glass poling. The devices, made with silica-on-silicon technology, are poled with periodic, embedded electrodes, and used for second-harmonic generation. We obtain precise control of the quasi phase-matching wavelength and bandwidth, and a normalised conversion efficiency of 1.

Direct experimental and numerical determination of extremely high group indices in photonic crystal waveguides.

We report on time-of-flight experimental measurements and numerical calculations of the group-index dispersion in a photonic crystal waveguide realized in silicon-on-insulator material. Experimentally group indices higher than 230 has been observed. Numerical 2D and 3D time-domain simulations show excellent agreement with the measured data.

Use of census data for construction of fertility history for Danish women.

Background: Modern epidemiology increasingly uses data on families. The authors constructed an extended fertility database for women born in Denmark from 1930 onwards by supplementing the existing Fertility Database with household data from the 1970 census.

Methods: A fertility history was constructed for all women participating in the 1970 census, but aiming for complete data only for women aged 20-39.

Violent behaviour among adolescents in Iceland: a national survey.

Background: Violence among adolescents may have serious developmental, physical, and mental health consequences for the affected individuals. In this study, we assessed the prevalence of violent behaviour and its correlates among 15-16 year old schoolchildren in Iceland.

Methods: In 1997, a cross-sectional survey was conducted among a random half of all Icelandic schoolchildren aged 15-16 years.

Fertility pattern does not explain social gradient in breast cancer in denmark.

The present study was undertaken to assess the impact of reproductive behavior on the social class gradient in breast cancer occurrence in Denmark. Objectives were to study whether the gradient across socioeconomic groups could be explained by fertility differences, whether the gradient across educational groups could be explained by fertility differences and whether the effect of socioeconomic group on breast cancer incidence and mortality could be explained by education and vice versa. We studied 674,084 women aged 20-39 at the census on 9 November 1970 for whom we had complete data on fertility history.

Women's death in Scandinavia--what makes Denmark different?

Objective: To compare the mortality for women in Sweden, Norway and Denmark in order to search for clues for the low life expectancy of Danish women.

Methods: Prospective age-period-cohort study covering 40 years for all Swedish, Norwegian and Danish women aged 40-84 during the period 1960-2000, and born 1900-1950.

Outcome Measures: Relative risks and 95% confidence intervals for deaths.