Search results for " monozygotic"
showing 10 items of 106 documents
Differences in hand and foot psychomotor speed among 18 pairs of monozygotic twins discordant for lifelong vehicular driving.
1997
The purpose of this study was to examine driving as a determinant of hand and foot psychomotor reaction times. Visual simple and choice hand and foot psychomotor reaction times were measured. The occupational driving contrast was determined by an interview reviewing every job held during each subject's lifetime. Comparison was made of psychomotor speed among 18 pairs of 39- to 62-year-old monozygotic male twins discordant for lifelong occupational driving. The mean discordance was the equivalent of 16 years of full-time driving. The twins who drove more tended to have slower hand simple and choice reaction times, although only the difference in hand-choice decision time was statistically si…
Monozygotic twinning after assisted reproductive technologies: a case report of asymmetric development and incidence during 19 years in an internatio…
2015
Objective To describe a case of monozygotic twinning with asymmetric development following a single fresh embryo transfer as part of an intracytoplasmic sperm injection (ICSI) treatment. Secondarily, to report the incidence of monozygotic twinning at the IVI (Instituto Valenciano de Infertilidad) clinics. Design Case report. Setting Private fertility centers. Patient(s) A 33-year-old woman with a 2-year history of primary infertility. Intervention(s) Controlled ovarian hyperstimulation and ICSI treatment with single-embryo transfer. Main Outcome Measure(s) Incidence of monozygotic twinning at the IVI clinics. Result(s) We report a twin pregnancy after a single-embryo transfer. Twins were di…
Genetic and environmental contributions to plasma C-reactive protein and interleukin-6 levels--a study in twins.
2006
Elevated baseline levels of acute-phase proteins such as C-reactive protein (CRP) or cytokines like interleukin-6 (IL-6) are known risk factors for atherosclerosis and cardiovascular disease (CVD) events. However, until today, there is only controversial information about the contribution of genetic and environmental factors. Therefore, we performed an open prospective study in 108 monozygotic (MZ) and 60 same-sex dizygotic (DZ) twin pairs to analyse the genetic and environmental contributions to plasma CRP and IL-6 levels. Heritability of IL-6 was 0.61, indicating that plasma IL-6 levels are to a major part influenced by genetic determinants; however, for CRP, heritability was only 0.22, p…
Associations between long-term physical activity, waist circumference and weight gain: a 30-year longitudinal twin study.
2007
Background and objective: Physical activity level and obesity are both partly determined by genes and childhood environment. To determine the associations between long-term leisure-time physical activity, weight gain and waist circumference and whether these are independent of genes and childhood effects. Design and subjects: The study design is a 30-year follow-up twin study in Finland. For this study, 146 twin pairs were comprehensively identified from the large Finnish Twin Cohort. These twin pairs were discordant for both intensity and volume of leisure physical activity in 1975 and 1981 and were healthy in 1981. At follow-up in 2005, both members of 89 pairs were alive and participated…
Lifetime exercise and disk degeneration: an MRI study of monozygotic twins.
1997
Participation in some competitive sports has been shown to increase disk degeneration; however, the long-term effects of recreational physical activities are unclear. We investigated the effects of endurance exercise and power sports on disk degeneration in monozygotic male twins with contrasting lifetime exercise histories. The effects of endurance exercise were studied in 22 discordant twin pairs (mean lifetime frequencies of 3.9 vs 1.1 times/wk), and the effects of power sports were investigated in 12 discordant pairs (2,300 vs 200 h of weightlifting). The age range of the twins was from 35 to 69 yr. No differences in MRI findings between co-twins discordant for endurance exercise were f…
Motor Development and Physical Activity: A Longitudinal Discordant Twin-Pair Study.
2015
ntroduction : Previous longitudinal research suggests that motor proficiency in early life predicts physical activity in adulthood. Familial effects including genetic and environmental factors could explain the association, but no long-term follow-up studies have taken into account potential confounding by genetic and social family background. The present twin study investigated whether childhood motor skill development is associated with leisure-time physical activity levels in adulthood independent of family background. Methods : Altogether, 1550 twin pairs from the FinnTwin12 study and 1752 twin pairs from the FinnTwin16 study were included in the analysis. Childhood motor development wa…
A genome-wide association study of monozygotic twin-pairs suggests a locus related to variability of serum high-density lipoprotein cholesterol
2012
Serum lipid levels have been associated with cardiovascular diseases, metabolic syndrome and type II diabetes (Kannel et al., 1961; Miller & Miller, 1975; Pilia et al., 2006). Variation in lipids levels is highly influenced by heritable factors (Friedlander et al., 1997) and 95 loci have already been associated with levels of high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, triglycerides (TG) and total cholesterol (TC) in numerous study samples and replicated in various populations using genome-wide approaches (Aulchenko et al., 2008; Kathiresan et al., 2008; Kooner et al., 2008; Teslovich et al., 2010; Willer et al., 2008). However, the genetic associa…
Differences in Corneal Anatomy in a Pair of Monozygotic Twins Due to Continuous Contact Lens Wear
2003
Purpose To study the differences in the corneal anatomy in a pair of 31-year-old monozygotic female twins, one of whom has been a contact lens wearer for the past 15 years and the other is a nonwearer. Methods We analyzed the corneal thickness and the corneal endothelial cell density of the monozygotic twins and of two age-matched control groups, one made up of non-contact lens wearers (35 eyes of 35 patients; mean age, 29.32 +/- 2.83 years) and the other made up of soft contact lens wearers (30 eyes of 30 patients; mean age, 33.08 +/- 3.72 years; mean duration of contact lens use, 10.62 +/- 4.32 years). Five corneal thickness measurements were carried out with the Orbscan Topography System…
Biological clocks and physical functioning in monozygotic female twins
2018
Background Biomarkers of biological aging – DNA methylation age (DNAm age) and leukocyte telomere length (LTL)– correlate strongly with chronological age across the life course. It is, however, unclear how these measures of cellular wear and tear are associated with muscle strength and functional capacity, which are known to decline with older age and are associated with mortality. We investigated if DNAm age and LTL were associated with body composition and physical functioning by examining 48 monozygotic twin sisters. Methods White blood cell DNAm age (predicted years) was calculated from Illumina 450 k BeadChip methylation data using an online calculator. DNAm age acceleration was define…
Body Fat and Mobility Are Explained by Common Genetic and Environmental Influences in Older Women
2008
In older adults, mobility limitations often coexist with overweight or obesity, suggesting that similar factors may underlie both traits. This study examined the extent to which genetic and environmental influences explain the association between adiposity and mobility in older women. Body fat percentage (bioimpedance test), walking speed over 10 m, and distance walked in a 6-min test were evaluated in 92 monozygotic (MZ) and 104 dizygotic (DZ) pairs of twin sisters reared together, aged 63-76 years. Genetic and environmental influences on each trait were estimated using age-adjusted multivariate genetic modeling. The analyses showed that the means (and s.d.) for body fat percentage, walkin…