Candidate gene expression in response to low-level air pollution

Background The progression of Helicobacter pylori-associated gastritis towards atrophic gastritis is modulated by host-related and environmental factors. Studies that explore the possible involvement of host-related versus environmental factors in the development of gastritis phenotype induced by H. pylori are highly needed. Aims Our study was aimed at investigating the phenotype of H. pylori-associated gastritis in two cohorts of monozygotic and dizygotic twins, using the OLGA/OLGIM gastritis staging system. Methods Two cohorts of monozygotic (14 pairs) and dizygotic (15 pairs) dyspeptic twins prospectively underwent endoscopy with biopsy sampling based on Sydney protocol. H. pylori status and OLGA/OLGIM stages were assessed and compared. Results The mean age of monozygotic and dizygotic twins was 40.4 and 38.6 years, respectively (p = 0.623). The overall prevalence of H. pylori infection was 51.7%. Among the 14 monozygotic twin pairs, five pairs were H. pylori-positive, four were H. pylori-negative, and five were H. pylori-discordant. Among the 15 dizygotic twin pairs, five pairs were H. pylori-positive, five were H. pylori-negative, and five were H. pylori-discordant. Concordance for antrum atrophy in monozygotic twins was 78.6% (11/14 pairs) and in dizygotic twins 73.3% (11/15 pairs) (p = 0.742). Concordance for corpus atrophy in monozygotic versus dizygotic twins was 92.9% (13/14 pairs) and 86.7% (13/15 pairs), respectively (p = 0.584). Concordance for antrum intestinal metaplasia (IM) in monozygotic twins was 85.7% (12/14 pairs) and in dizygotic 73.3% (11/15 pairs) (p = 0.411). Concordance for corpus IM in monozygotic twins was 85.7% (12/14 pairs) and in dizygotic 86.7% (13/15 pairs) (p = 0.941). Among monozygotic and dizygotic subjects, the stage of gastritis was concordant in both H. pylori-positive and H. pylori-negative subjects. Conclusions In conclusion, histological gastric mucosa alterations in monozygotic and dizygotic twins showed high rates of concordance. Furthermore, OLGA/OLGIM gastritis stages were not modulated by the zygosity of the twins.

The twin study method is deemed to be the most reliable one in order to study the hereditary and environmental influences upon the development of intelligence. Among the various conditions the problem of early physical conditions was this time taken up, using individual intelligence test scores obtained from 269 pairs of monozygotic (MZ) twins and 64 pairs of same-sexed dizygotic (DZ) twins, all twelve years of age. Among the results obtained, the statistically significant ones were as follows:I. The analysis of the physical conditions compared between MZ and DZ twins indicated that MZ twins showed much more similar birth weights, a shorter time interval in birth, and less difference in the initiation of walking than DZ twins. As to MZ twins with a great difference in the start of walking, it was found that the first-born, or the heavier twin began to walk earlier than the other twin, while this relationship could not be seen in DZ twins.II. The view of many previous researchers that MZ twins as a whole show higher degree of conformity in the development of intelligence than DZ twins was not supported by all cases of our MZ twins, and in some MZ twins a great difference of intelligence was found. This difference was considered having been caused by the environmental factors.III. Those MZ twins who showed a great intra-pair difference in their biological conditions at birth were selected. The comparative analysis of the data indicated that1) as to pairs with a great intra-pair difference in birth weight, the heavier twin showed the higher intelligence score, 2) as to pairs with a long intra-pair interval in birth, the first born showed the higher score, 3) when a twin was born with asphyxia neonatorum, he showed a lower score, and4) those twins who showed a great difference in intelligence scores also showed a difference in their initiation of walking and/or talking.Although there was a tendency that MZ twins were born with much more similar physical conditions than DZ twin, there was a great intra-pair difference observed in the development of intelligence at the age of twelve if MZ twins passed through different physical conditions at birth. A definite relationship between the early physical conditions and the intelligence development was thus illustrated, that is, the MZ twin born with superior conditions generally showed superiority in the development of intelligence.

Materials and methods. The source of information on fertility and mortality was Russian Federal State Statis-tics Service data on 173 cities of the Russian Federation with a population of more than 100 thousand peo-ple for 2014-2016. The sources of air pollution were the Yearbooks of the state of air pollution in cities in Russia for the same period. A nonparametric analysis of variance was used to compare cities with different levels of air pollution in terms of fertility, mortality, birth-death and aging index. Results. Comparison of groups of cities with different maximum one-time levels of atmospheric pollution with benzo[a]pyrene revealed significant differences between the groups in terms of total fertility and mortal-ity rates, birth-death ratio and aging index. Comparison of groups of cities with different average annual levels of air pollution for 19 pollutants showed that only for benzo[a]pyrene, nitrogen dioxide, nitric oxide and ammonia a statistically significant relation-ship with the characteristics of population health was found. For benzo[a]pyrene, the results were similar to those obtained for the maximum one-time concentrations of benzo[a]pyrene (except for the total mortality rate, for which the relationships are not significant). Statistically significant relationships of air pollution with nitrogen dioxide, nitrogen oxide and ammonia were revealed with the total mortality rate and the birth-death ratio, and for ammonia pollution also with the demographic aging index. Conclusion. In cities of the Russian Federation, the maximum one-time air pollution with benzo[a]pyrene is statistically significantly associated with the total fertility rate, birth-death ratio and the aging index: in groups of cities with an increase in the level of atmospheric air pollution, the median values of the total fer-tility rate and the birth-death ratio are increasing, and the median values of the aging index are decreasing. Comparison of groups of cities with different average annual levels of air pollution for 19 pollutants re-vealed statistically significant effects for pollution with benzo[a]pyrene, nitrogen dioxide, nitrogen oxide and ammonia. A statistically significant heterogeneity of the groups of cities with different average annual levels of benzo[a]pyrene was revealed in terms of the total fertility rate, birth-death ratio and aging index: with an increase in the level of atmospheric air pollution, the median values of the total fertility rate and the birth-death ratio increase, while the median values of the aging index decrease. A statistically significant hetero-geneity of the groups of cities with different average annual levels of air pollution with nitrogen dioxide, ni-tric oxide and ammonia was revealed in terms of the total mortality rate and the birth-death ratio, and for ammonia pollution also in terms of the demographic aging index. In cities with a high level of air pollution with nitrogen dioxide and ammonia, the total mortality rate is higher.

Sleep and dream patterns in twins. Markov analysis of a genetic trait.

Dental development, one of the most reliable indicators of chronological age (CA), has been believed to be fundamentally influenced by genetics rather than environmental factors. The study aims (i) to compare dental ages (DAs) in monozygotic (MZ) and dizygotic (DZ) twins using three different DA methods and determining the most appropriate method, and (ii) to determine the possible effects of genetics on DA by evaluating the differences in the estimated DAs of MZ and DZ twins. The study sample consisted of 171 twin pairs (47 monozygotic, 124 dizygotic) between the ages of 5.0 and 12.9. In order to estimate DA, Demirjian, Willems and Nolla methods were used. The mean CA of group was 8.42 (2.05) years. The Demirjian, Willems and Nolla methods overestimated the DAs by 0.69, 0.60 and 0.56 years, respectively. The estimated DAs in age groups were similar, and differences were not statistically significant for intrapair DZ and MZ twins. As a result, it was not correct to state that any method was more appropriate and better than others for studies of twins. All methods’ standards were not suitable for any age groups of MZ and DZ twins, except for twins aged 12–12.9 years. Country-wide samples are needed to gather enough data to create valuable results and to establish the applicability of methods used.

Study the influence of age, zygosity and birth weight on insulin action and insulin secretion in twins. In vivo insulin action and insulin secretion were measured using the euglycaemic, hyperinsulinaemic clamp technique and intravenous glucose tolerance test, respectively. We examined 104 monozygotic (MZ) twins and 88 dizygotic (DZ) twins in two age groups (25-34 and 57-66 years). There were no differences in birth weight, body mass index, waist to hip ratio or lean body mass between monozygotic and dizygotic twins. Younger monozygotic twins had a slightly higher insulin-stimulated glucose uptake (M) than younger dizygotic twins. In contrast, elderly monozygotic twins had a lower insulin-stimulated glucose uptake value compared with elderly dizygotic twins. Elderly monozygotic twins had a reduced insulin secretion relative to insulin resistance compared to dizygotic twins during oral glucose tolerance test (OGTT). Birth weight per se was not associated with insulin secretion or action in the twins. However, correcting for the genetic influence on birth weight using intrapair differences among monozygotic twin pairs, low birth weight was associated with insulin resistance and low insulin secretion after both oral and intravenous glucose administration in elderly MZ twins. Zygosity status has a major age (or time) dependent impact on in vivo insulin secretion and insulin action in twins independent of birth weight and adult antropometry. An additional non-genetic impact of low birth weight on insulin secretion and insulin action was found in elderly monozygotic twins. Ageing could play an important role by unmasking the influence of an adverse intrauterine environment on insulin resistance and low insulin secretion in twins.

Background: Air pollution has been linked to increased rates of mortality, but little is known about individual characteristics related to the increase in risk. Aims: To examine short term effects...

Control of Splicing Efficiency by the Mouse Histone H2a Element in a Murine Leukemia Virus–based Retroviral Vector

The heritability of anxiety and its association with insomnia have been suggested. This study investigated the coincidence of anxiety and insomnia in monozygotic twins compared to dizygotic twins. The Korean Genome and Epidemiology Study 2005–2014 was used. The ≥20-year-old cohort population was composed of 1300 twin participants. A total of 980 monozygotic twins and 232 dizygotic twins were compared for the concordance for the history of insomnia in both twin pairs (coincidence of insomnia) and the difference in state of anxiety and trait of anxiety scores. The odds ratios (ORs) for the coincidence of insomnia in monozygotic twins compared to dizygotic twins were analyzed using multiple logistic regression analysis. The estimated values (EV) of the difference of state and trait of anxiety scores were analyzed using a linear regression model. The coincidence of insomnia was not high in monozygotic twins compared to dizygotic twins. The difference in the state of anxiety score was comparable between monozygotic twins and dizygotic twins. However, the difference in anxiety scores was higher in dizygotic twins than in monozygotic twins. The monozygotic twin group did not demonstrate higher coincidence of insomnia or the state of anxiety than the dizygotic twin group. However, the monozygotic twin group indicated higher coincidence of the trait of anxiety than the dizygotic twins. The current results implied the potential contribution of heritable factors for the trait of anxiety.

Monozygotic (MZ) twins spend more time with each other and are more genetically alike than are dizygotic (DZ) twins or nontwin siblings and therefore probably experience less diversity in their playmates than DZ twins, who in turn may experience less diversity than other-age siblings. Thus MZ twins may be more inhibited than DZ twins, who may in turn be more inhibited than nontwin siblings. To test this, 205 children (42 MZ twins, 94 DZ twins, and 69 nontwin siblings) were assessed in a playroom laboratory during free play with an unfamiliar peer. Children's inhibition was rated based on latency to touch a toy for the first time and amount of time spent interacting with the other child. Additionally, the Child Behavior Checklist (CBCL) withdrawn scale was used to assess inhibition according to parent report. Behavioral ratings showed that MZ and DZ twins did not significantly differ on the inhibition or withdrawn ratings. DZ twins were significantly more inhibited than were nontwin siblings, according to laboratory ratings. Greater inhibition of twins during the free peer play situation can be explained by their relative lack of experience in playing with children who are less genetically and phenotypically like themselves. Parental ratings showed exactly the opposite pattern, suggesting a rater bias effect.

Understanding the factors leading to the development of allergic disease is a critical area of research. We studied the development of allergic disease in identical and fraternal twins to identify potential differences in environment versus genetic factors. Twins aged up to 4 years were selected for inclusion in this long-term follow-up study. Regular questionnaire results, allergen levels, and other indicators were examined. A total of 80 twins were included in this study. Over time, the incidence of atopic dermatitis (AD) decreased, and the incidence of rhinitis and wheezing increased. The incidence of AD, rhinitis, and food allergy was significantly higher in identical twins than fraternal twins. The consistency of positive inhaled allergens and positive food allergens was significantly higher in the identical twins than fraternal twins. The factors influencing allergic diseases were analyzed. In the identical twins, AD was more frequent in males, those with a birth weight <2,500 g, and having siblings; rhinitis was more frequent in those living in a bungalow style home, having pets, and carpeting; and wheezing was more frequent in males, having a birth weight <2,500 g, and having siblings. In the fraternal twins, AD was more frequent in those born <37 weeks gestation, and having flowers and plants in the house; rhinitis was more frequent in those born <37 weeks gestation, those with a history of neonatal asphyxia, and having a household smoking; and wheezing was more frequent in those born <37 weeks gestation, those with a history of neonatal asphyxia, with central heating, and household smoking. No factors were found to affect the occurrence of food allergy. Allergic diseases in children have a strong genetic predisposition, but are also influenced by environmental factors. The environmental factors affecting the occurrence of allergic diseases in identical and fraternal twins differ.

We sought in this study to clarify the role that familial factors play in influencing the clinical presentation of major depression (MD). We examined the similarity of the historical and symptomatic features of MD in 176 pairs of female-female monozygotic (MZ) and dizygotic (DZ) twins from a population-based registry, where both members reported a history of MD defined by DSM-III-R criteria. The age at onset and treatment-seeking were significantly correlated in all twin pairs and the correlation in concordant DZ pairs was actually somewhat higher than in concordant MZ twins. The degree of impairment was modestly correlated in all twin pairs with substantially higher correlations in MZ vs DZ twins. No twin resemblance was observed for number of episodes or longest duration of an episode. Twin resemblance for the clinical features of MD was modest, but so was their consistency for the same individual over successive 1-year periods. However, in 5 of the 6 neurovegetative symptoms involving changes in appetite, weight and sleep, MZ twins were significantly correlated and correlations were significantly greater in concordant MZ vs DZ twins. Although the familial factors that cause twin resemblance for the age at onset and treatment seeking appear to be largely environmental, twin resemblance for the degree of impairment and neurovegetative symptoms are probably due largely to genetic factors. Our results suggest that familial factors influence the predisposition to some clinical features of MD.

The equal environments assumption (EEA) of the twin method posits that environmental influences that are etiologically relevant to a given phenotype are no more likely to be shared by monozygotic (MZ) than dizygotic (DZ) twin pairs. One method of testing the EEA is to evaluate whether increased rearing environment similarity in MZ twin pairs compared to DZ twin pairs is related to increased phenotypic correlation. In a sample of 885 twin pairs, we contrasted similarity in rearing environment between MZ and DZ twin pairs, examined the correlation between similarity in rearing environment and conduct disorder (CD), oppositional-defiant disorder (ODD), inattention, and hyperactivity-impulsivity symptom dimensions, and tested the effects of differential similarity in rearing environments between MZ and DZ twin pairs by testing whether rearing environment similarity moderated the correlations for the externalizing symptom dimensions. We found that MZ twins experienced substantially more similar rearing environments than DZ twins, but that there was little evidence that MZ and DZ correlations for the externalizing symptom dimensions varied by rearing environment similarity. Thus, these results constitute evidence for the validity of the EEA for childhood externalizing disorders.

Brain Fog: Does Air Pollution Make Us Less Productive?

Twins are a source of curiosity, both for the family and the scientific community. Genetic similarities between twins have been the preferred choice to study the heritability of traits. The fact that nature and nurture play a significant role in shaping one’s phenotype has prompted Geneticists to use twins as a proxy to address this fact. Based on the similarities, twins are of two types, monozygotic twins (MZ) and Dizygotic twins (DZ). Identical or monozygotic twins are formed when one fertilized egg (ovum), fertilized by one sperm, splits and develops into two embryos with precisely the same genetic information. The combined ratio of MZ and DZ to singleton delivery is approx 1: 100. On the other hand, fraternal or dizygotic twins are formed when two eggs (ova) are fertilized by two sperm and produce two genetically unique children in the same pregnancy. Monochorionic twins are genetically identical, sharing the same placenta. If more than two twins share the placenta, these are monochorionic multiples. Monochorionic twins occur in 0.3% of all pregnancies. Monozygotic (identical) twins share all their genes, while dizygotic (fraternal) twins only share about 50%. Hence, any similarity seen between identical twins when comparing the similarity between sets of fraternal twins for a trait or condition is most probablydue to genes rather than environment. TWIN REGISTRIESProgress in twin research worldwide is carried out by establishing Twin registries or consortia based on collaborations of several twin families. These registries are a rich source of materials for Twin research. It is much needed to establish such Twin registries in India. With its 1.5 Billion population, Indian Twin registries can be a source of materials for Twin Research for the whole world.