P300 amplitude in nonalcoholic adolescent twin pairs who become discordant for alcoholism as adults

Past reports suggest that reduced P300 amplitude is associated with risk for alcoholism. We examined whether visual P300 amplitude could identify familial risk for alcohol disorders in individuals not known to be at risk at the time P300 was recorded. These individuals were twins from pairs where neither twin had an alcohol disorder at age 17 but familial risk was established at age 20 when one twin developed an alcohol disorder whereas the other did not. Of special interest was the P300 of the unaffected twin recorded at age 17 when both twins were alcoholism free. We found reduced P300 in the unaffected twin compared to pairs where both members were continuously disorder free. Hence, P300 was reduced in alcohol disorder-free individuals whose twin siblings subsequently developed alcoholism, further supporting reduced P300 amplitude as an endophenotype indexing familial risk for alcoholism.     

Magnitude of right-to-left shunt as the only determinant of stroke in a pair of identical twins

Abstract. Right-to-left shunt due to patent foramen ovale is a well-established risk factor for stroke in the young. The magnitude of shunt seems to be correlated to the risk of stroke in individuals. We report the cases of two 51-year-old identical twins, with similar risk factors for ischemic stroke, in which the sibling with a large and permanent shunt suffered a left hemispheric stroke and the other, with a small and latent shunt, was asymptomatic. In a three-year follow-up, the siblings were both asymptomatic, and the dimensions of shunts were unchanged. Our cases stress the importance of quantifying right-to-left shunt in order to stratify the risk of stroke in individuals, and suggest a role of heredity in patency of foramen ovale.     

Status epilepticus in a population-based Virginia twin sample

PURPOSE: To characterize status epilepticus (SE) and estimate its frequency of first occurrence, as well as to assess the contribution of genetic factors to risk of SE occurrence in a sample of Virginia-born twins ascertained from the population-based Mid-Atlantic Twin Registry. METHODS: The occurrence of SE was determined in 13,506 unselected Virginia-born twin pairs ascertained from birth records. Twins included in the study were between ages 2 and 75 years when surveyed. History of seizures and SE was validated through medical records and by detailed personal or parental interviews. RESULTS: Among 381 twins included in 332 pairs with a verified history of seizures, 70 (18.4%) were validated to have had at least one episode of SE. The frequency of first SE in this sample was 309 per 100,000 twins. First SE occurred in conjunction with 21 of 158 febrile and 49 of 223 afebrile seizure cases, respectively. Mean length of SE episode was 76.2 +/- 14.9 min. Age at first SE occurrence ranged from 2 months to 59 years. All concordant twin pairs in the sample were monozygotic (MZ), with a proband-wise concordance rate estimated for SE in this population of 0.31 [95% confidence interval (CI), 0.14-0.52) overall, and 0.67 (95% CI, 0.35-0.90) in pairs concordant for epilepsy. CONCLUSIONS: These results provide a direct estimate of the frequency of SE in a defined population of twins and afford further evidence for a genetic contribution to risk for SE.     

双胎之一完全性葡萄胎的产前诊断及处理

目的 探讨双胎之一完全性葡萄胎(a twin pregnancy consisting of acomplete mole and coexisting fetus,CMCF)的产前诊断及处理。方法 回顾性分析2例CMCF的临床资料。结果 第1例患者在孕10周时,B超发现胎儿与葡萄胎胎盘共存,患者要求终止妊娠,刮宫物间期细胞荧光原位杂交(fluorescent in situ hybridization,FISH)和核型分析提示,胎儿与葡萄胎均为二倍体,证实为CMCF。第2例患者在孕21周时,B超发现胎儿与葡萄胎胎盘共存,B超引导下经腹壁绒毛活组织检查(活检)和羊膜腔穿刺,葡萄胎和羊水的间期细胞FISH和核型分析提示,胎儿与葡萄胎均为二倍体,证实为CMCF双胎之一完全性葡萄胎,患者继续妊娠,在孕28周时胎膜早破,因继发感染而行剖宫产终止妊娠,胎儿存活,胎盘、新生儿外周血的核型分析结果与产前诊断相符。结论 产前一旦发现胎儿与葡萄胎胎盘共存,应立即进行CMCF和部分性葡萄胎(partial hydatidiform mole,PHM)的鉴别,如果绒毛和羊水行间期细胞FISH和核型分析为二倍体,则为CMCF,是否继续妊娠,需采取个体化原则;如果为三倍体,则为部分性葡萄胎,应及时终止妊娠。     

Heritability of explosive power and anaerobic capacity in humans

There is a disparity in the information about the heritability of the response of muscle anaerobic metabolism to exercise and the use of explosive power, as well as a lack of information concerning the genetic determinants of this form of work, as measured using different specific physical tests. We applied a battery of some of the commonly employed procedures (Ergojump, Wingate, maximal accumulated oxygen deficit, excess post-exercise oxygen consumption, and Δ lactate concentration) to a group of 32 Caucasian male twins, 8 monozygotic and 8 dizygotic pairs, who had similar environmental backgrounds. Results were studied using a heritability index (HI). Zygosity was determined using the identity of erythrocyte antigens, protein and enzyme polymorphism and human leucocyte antigen serologic types between co-twins. Significant HI values (P<0.05) were found in the following tests: maximal 5 s power (HI=0.74) and total power in a 30 s interval (HI=0.84) in the Wingate test, maximal lactate concentration (HI=0.82) and Δ lactate concentration (HI=0.84) in the maximal progressive test, as well as in the 2nd (HI=0.93) and in the 3rd min (HI=0.92) of recovery after the deficit test. In this study, the most relevant findings were: firstly, significant HI values for many of the variables studied; secondly, the HI values of the parameters used to evaluate explosive power were higher than those of lactic acid capacity and thirdly, the HI of certain variables from different tests measuring, in theory, similar qualities, were different. Electronic Publication     

Life-course financial strain and health in African–Americans

Differential exposure to financial strain may explain some differences in population health. However, few studies have examined the cumulative health effect of financial strain across the life-course. Studies that have are limited to self-reported health measures. Our objective was to examine the associations between childhood, adulthood, and life-course, or cumulative, financial strain with disability, lung function, cognition, and depression. In a population-based cross-sectional cohort study of adult African–American twins enrolled in the US Carolina African American Twin Study of Aging (CAATSA), we found that participants who reported financial strain as children and as adults are more likely to be physically disabled, and report more depressive symptoms than their unstrained counterparts. Participants who reported childhood financial strain had lower cognitive functioning than those with no childhood financial strain. We were unable to detect a difference in lung function beyond the effect of actual income and education in those who reported financial strain compared to those who did not. Financial strain in adulthood was more consistently associated with poor health than was childhood financial strain, a finding that suggests targeting adult financial strain could help prevent disability and depression among African–American adults.     

Primiparity, assisted reproduction, and preterm birth in twin pregnancies: a population based study

Objective To determine the prevalence of pregnancy complications among primiparous patients with twin gestation in our population and to investigate the association between the increased rates of assisted reproduction (ART) in twin gestation and preterm birth (PTD). Material and methods A retrospective population based cohort study was designed, including all twin deliveries after 24 weeks gestation (n = 2,601). The study group included 666 primiparous women and the comparison group 1,935 multiparous women. Maternal characteristics and perinatal outcome were evaluated. Women with fetal malformations were excluded. A multiple logistic regressions analysis for independent risk factors was performed including factors that were significantly different between the study groups in the univariate analysis. Patient’s data were obtained from computerized database and analyzed using SPSS statistical package. Results Primiparous women had a significantly higher rate of preeclampsia, chronic hypertension, ART, prelabor rupture of membranes (PROM) preterm deliveries (PTD), labor dystocia, cesarean section (CS) and vacuum extraction of the first twin than the multiparous group. Primiparous patients had a significantly lower gestational age at delivery and neonatal birth weight of the first and second twin. In multiple logistic regressions analysis primiparity and ART were independent risk factors for PTD, (OR 1.45, 95% CI 1.18–1.78; OR 1.36, 95% CI 1.09–1.71, respectively). Conclusions (1) Primiparous patients with twin gestation represent a unique population with high rate of infertility and underlying diseases such as chronic hypertension in comparison to the multiparous women with twin gestation; (2) primiparity is an independent risk factor for prematurity in twin gestations; and (3) although primiparous women had an increased maternal complications, neonatal mortality rates were not significantly different from multiparous women.     

External hydrocephalus in discordant birth weight twins: a case report

The term “external hydrocephalus (EH)” is used to describe excessively rapid head growth in infants who are found to have enlarged subarachnoid spaces and little or no ventricular enlargement. EH has not yet been described in discordant birth weight twins.

We report the cases of two sets of discordant twins with normal neonatal course and normal neonatal brain ultrasound scans who developed an EH in the first months after birth and had a mild neurodevelopmental delay.

Our findings suggest that EH may be part of neurologic morbidity in discordant birth weight twins and represents one of the potential complications to look for in the follow-up of these infants.     

6例双绒双胎妊娠中期选择性减胎后胎膜早破患者妊娠结局分析

目的：回顾性分析通过辅助生殖技术受孕的双绒毛膜双羊膜囊双胎（双绒双羊双胎）妊娠中期减胎后发生胎膜早破患者的妊娠结局,为临床妊娠中期胎膜早破患者的治疗提供一定的临床依据。方法：收集2012年1月—2018年2月在武汉大学人民医院生殖中心选择性减胎后发生胎膜早破的双绒双羊双胎妊娠患者6例,患者受孕方式为体外受精（IVF）或胞浆内单精子注射（ICSI）,绒毛膜性在妊娠早期超声诊断为双绒双羊双胎,孕12～16周接受选择性减胎。结果：6例患者均减胎成功,减灭的胎儿除了1例为右侧胎儿,1例为左下方胎儿,其余4例均为下方胎儿。减胎后胎膜早破均发生在减胎后的24 h内,所有患者均在减胎胎膜早破后8 d之内（2～8 d）停止阴道流液。整个妊娠期1例患者妊娠晚期羊水过少,1例因胎膜早破早产,1例合并妊娠期糖尿病,另3例患者无异常。除了胎膜早破早产患者分娩孕周为34+6周,其余均为足月分娩,其中有4例患者剖宫产,2例经阴道顺产。新生儿体质量为2 200～3 400 g,4名男婴,2名女婴,除早产儿合并肺部感染外,其余新生儿均无并发症。结论：辅助生殖技术受孕双绒双胎妊娠中期选择性减胎后胎膜早破患者可以建议期待治疗,其妊娠结局可能是令人满意的,然而仍需要大样本研究来证实。     

Common Genetic Contributions to Alcohol and Cannabis Use and Dependence Symptomatology

Background: Despite mounting evidence that use of and dependence on alcohol and cannabis are influenced by heritable factors, the extent to which heritable influences on these phenotypes overlap across the 2 substances has only rarely been explored. In the current study, we quantified cross‐substance overlap in sources of variance and estimated the degree to which within‐substance associations between use and dependence measures are attributable to common genetic and environmental factors for alcohol and cannabis. Methods: The sample was comprised of 6,257 individuals (2,761 complete twin pairs and 735 singletons) from the Australian Twin Registry, aged 24 to 36 years. Alcohol and cannabis use histories were collected via telephone diagnostic interviews and used to derive an alcohol consumption factor, a frequency measure for cannabis use, and DSM‐IV alcohol and cannabis dependence symptom counts. Standard genetic analyses were conducted to produce a quadrivariate model that provided estimates of overlap in genetic and environmental influences across the 4 phenotypes. Results: Over 60% of variance in alcohol consumption, cannabis use, and cannabis dependence symptoms, and just under 50% of variance in alcohol dependence (AD) symptoms were attributable to genetic sources. Shared environmental factors did not contribute significantly to the 4 phenotypes. Nearly complete overlap in heritable influences was observed for within‐substance measures of use and dependence symptoms. Genetic correlations across substances were 0.68 and 0.62 for use and dependence symptoms, respectively. Conclusions: Common heritable influences were evident for alcohol and cannabis use and for AD and cannabis dependence symptomatology, but findings indicate that substance‐specific influences account for the majority of the genetic variance in the cannabis use and dependence phenotypes. By contrast, the substantial correlations between alcohol use and AD symptoms and between cannabis use and cannabis dependence symptoms suggest that measures of heaviness of use capture much of the same genetic liability to alcohol‐ and cannabis‐related problems as dependence symptomatology.