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1.
J Forensic Odontostomatol ; 2(38): 40-46, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-33174536

RESUMEN

Lip print patterns are referred to as unique to each individual, but controversy exists surrounding twins. In this study, the lip prints of 19 pairs of monozygotic and 47 pairs of dizygotic twins were studied. The left lower lip was photographed and the furrows were classified using Renaud's classification. Results showed the same lip pattern was found only in one monozygotic pair (5.3%) and in 4 dizygotic pairs (8.5%), and no significant statistical differences were found between groups (p > 0.05). In monozygotic twins only type C furrows presence displayed statistical significant differences (p=0.034). As for dizygotic twins, there were statistical significant differences in the frequency of type A (p=0.005) and type G furrows (p=0.018). As for the most common types, both groups displayed a higher prevalence of vertical furrows (type B: 97.4% and 96.8%, type A: 86.8% and 87.2%, in monozygotic and dizygotic, respectively). The least frequent furrow type was type I and type E in monozygotic (2.6% and 5.3%, respectively) and types E, F and I, in dizygotic (6.4%, 7.4%. and 7.4%, respectively). Our results seem to point out that lip print patterns should be useful carefully in twins' identification.


Asunto(s)
Labio , Gemelos Dicigóticos , Enfermedades en Gemelos , Humanos , Portugal , Gemelos Monocigóticos
2.
Stomatologija ; 21(2): 54-57, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33242030

RESUMEN

AIM OF THE WORK: If we figure out mandible asymmetry etiology, we can inspire further scientific research, create more effective treatment schemas and recommend means of prophylaxis that could stop mandible asymmetry development. The aim of this work was to analyze monozygotic and dizygotic twins' mandibular asymmetry in sagittal direction using cephalometric data and to analyze its dependence of genetic and environmental factors. MATERIAL AND METHODS: Study sample consisted of 80 dizygotic (DZ) and 80 monozygotic (MZ) twins of same sex. 3 cephalometric measurements were made to determine mandible asymmetry in sagittal direction. Indexes of mandibular asymmetry (IMA1, IMA2) were calculated. Data analysis was done using Microsoft Excel (2013). Genetic and environmental factors influencing mandible asymmetry was determined. RESULTS: Mandibular dental asymmetry was bigger in monozygotic twins' group but the results were not statistically significant. Mandibular skeletal asymmetry was significantly bigger in dizygotic twins' group: IMA1(DZ)=3.05±1.94, IMA1(MZ)=1.92±1.05, p=0.005. IMA2(DZ)=3.12±2.04, IMA2(MZ)=1.88±1.04, p=0.004. Distance between distal borders of the ramus is mostly determined by genetic factors. CONCLUSIONS: 1. Mandibular skeletal asymmetry was significantly bigger in dizygotic twins' group. Mandibular dental asymmetry and symmetry did not differ in groups significantly. 2. Skeletal mandible's asymmetry is more determined by genetics than environmental factors, but lower molars' sagittal position is determined more by environment.


Asunto(s)
Gemelos Dicigóticos , Gemelos Monocigóticos , Cefalometría , Humanos , Mandíbula , Diente Molar
3.
Medicine (Baltimore) ; 99(40): e22558, 2020 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-33019467

RESUMEN

RATIONALE: During ultrasound prenatal screening, absence of the fetal nasal bone is used as a marker for common aneuploidies in singleton pregnancies. However, its application in multiple pregnancies is less sensitive and more challenging owing to difficulties in obtaining adequate views of the fetal face. PATIENT CONCERNS: A 38-year-old woman with dichorionic-diamniotic (DCDA) pregnancy and a history of in vitro fertilization and embryo transfer was referred to our hospital with the absence of the nasal bone noted on ultrasound images obtained during the second trimester in 1 fetus. DIAGNOSIS: Prenatal sonographic examination revealed the absence of the nasal bone in 1 fetus in the DCDA gestation. Amniocentesis performed on the dual amniotic sacs revealed normal karyotypes for each twin. The absence of the nasal bone was confirmed on a radiograph obtained postnatally in 1 infant. INTERVENTIONS: The mother underwent routine outpatient care according to the gestational age and successfully delivered following lower-segment cesarean section. OUTCOMES: Two live infants were uneventfully delivered. Radiography confirmed the absence of the nasal bone in 1 of the newborns on postnatal day 3. The infants were followed up until 2 years and 9 months of age, which revealed normal appearance and eating and breathing functions. LESSONS: Prenatal diagnosis of the absence of nasal bone in 1 fetus of DCDA pregnancy has rarely been reported. Although a fetus with the absence of the nasal bone in DCDA gestation poses a significant risk of aneuploidy, it is acceptable when the defect is an isolated anomaly after ruling out genetic abnormalities. Appropriate consultation should be provided for these patients.


Asunto(s)
Fertilización In Vitro/efectos adversos , Hueso Nasal/anomalías , Diagnóstico Prenatal/métodos , Adulto , Amniocentesis/métodos , Cesárea/métodos , Transferencia de Embrión , Femenino , Feto , Humanos , Hueso Nasal/diagnóstico por imagen , Embarazo , Segundo Trimestre del Embarazo , Embarazo Múltiple , Radiografía , Gemelos Dicigóticos , Ultrasonografía Prenatal/métodos
5.
PLoS Negl Trop Dis ; 14(8): e0008424, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32745093

RESUMEN

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1-40% of cases of pregnant women infected by ZIKV, suggesting that mothers' infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses' tissues.


Asunto(s)
Expresión Génica , Trofoblastos/metabolismo , Gemelos Dicigóticos , Infección por el Virus Zika/congénito , Quimiocinas/metabolismo , Matriz Extracelular , Femenino , Predisposición Genética a la Enfermedad , Humanos , Células Madre Pluripotentes Inducidas , Lactante , Embarazo , Complicaciones Infecciosas del Embarazo/genética , Complicaciones Infecciosas del Embarazo/virología , Trofoblastos/virología , Virus Zika , Infección por el Virus Zika/genética
6.
Eur J Clin Microbiol Infect Dis ; 39(12): 2441-2445, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32661809

RESUMEN

Viral infections are common complications of pregnancy, with a wide range of obstetric and neonatal sequelae. Currently, there are limited data on whether SARS-CoV-2 is vertically transmitted in pregnant women tested positive for the virus. Here we describe a case of a known SARS-CoV-2-positive woman giving preterm birth to two fetuses with SARS-CoV-2 positive testing in placental tissue and amniotic fluid. The placental histological examinations showed chronic intervillositis and extensive intervillous fibrin depositions with ischemic necrosis of the surrounding villi.


Asunto(s)
Betacoronavirus/patogenicidad , Infecciones por Coronavirus/transmisión , Diabetes Gestacional/diagnóstico , Transmisión Vertical de Enfermedad Infecciosa , Neumonía Viral/transmisión , Complicaciones Infecciosas del Embarazo/diagnóstico , Nacimiento Prematuro/virología , Adulto , Líquido Amniótico/virología , Cesárea , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/patología , Infecciones por Coronavirus/virología , Diabetes Gestacional/patología , Diabetes Gestacional/virología , Femenino , Muerte Fetal , Feto , Humanos , Pandemias , Placenta/patología , Placenta/virología , Neumonía Viral/diagnóstico , Neumonía Viral/patología , Neumonía Viral/virología , Embarazo , Complicaciones Infecciosas del Embarazo/patología , Complicaciones Infecciosas del Embarazo/virología , Nacimiento Prematuro/patología , Gemelos Dicigóticos
7.
J Oral Rehabil ; 47(9): 1110-1119, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32613647

RESUMEN

BACKGROUND: Sleep bruxism (SB) and awake bruxism (AB) have been considered different entities, although co-occurrence between them has been shown. While genetic factors have a marked influence on phenotypic variance in liability to SB, this remains unclear for AB. AIM: To examine the degree of co-occurrence of SB and AB, and whether they have common correlates and also twin similarity of SB and AB bruxism traits by zygosity and sex. METHODS: A questionnaire was mailed to all twins born 1945-1957 in Finland in 2012 (n = 11 766). Age and sex adjusted logistic regression models were used. Twin similarity was assessed using polychoric correlations, and crosstwin-crosstrait correlations were computed. RESULTS: The response rate was 72% (n = 8410). Any SB was reported by 14.8% and ≥ 3 nights weekly by 5.0%. Percentages for any AB were 18.4% and 6.3%, respectively. There was substantial co-occurrence (29.5%) between SB and AB, and several shared correlates were found. For SB, the polychoric intra-class correlation was 0.366 in monozygotic (MZ) and 0.200 in dizygotic (DZ) pairs, without gender difference. A twofold crosstwin-crosstrait correlation was observed in MZ twins compared to DZ twins. CONCLUSIONS: The risk factor profiles of SB and AB were largely but not entirely similar. The higher correlation in MZ than in DZ pairs suggests the influence of genetic factors on both SB and AB. The higher crosstwin-crosstrait correlation in MZ than in DZ pairs suggests some degree of genetic influences shared by SB and AB.


Asunto(s)
Gemelos Dicigóticos , Vigilia , Finlandia , Humanos , Autoinforme , Gemelos Monocigóticos
8.
Medicine (Baltimore) ; 99(25): e20730, 2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32569212

RESUMEN

BACKGROUND: Published findings on perinatal outcomes of multifetal pregnancy reduction (MPR) of dichorionic diamniotic (DCDA) twin pregnancy to singleton are controversial. We performed a meta-analysis to appraise the effects of MPR of DCDA twin pregnancy versus expectant management on perinatal outcomes. METHODS: Four electronic databases were searched from their inception to June 15, 2019, to identify publications that appraised MPR before 15 weeks of gestation. Studies reporting perinatal outcomes of both MPR of DCDA twin pregnancy to singleton and expectant management were considered. The relative risks (RRs) and mean differences with 95% confidence intervals (CIs) were pooled using a random-effects model. RESULTS: Six studies involving 7398 participants showed that MPR of DCDA twin pregnancy to singleton was associated with a lower risk of preterm birth (5 studies with 7297 participants; RR: 0.30, 95% CI: 0.22-0.40; P < .001) and higher birth weight (4 studies with 5763 participants; mean differences: 548.10 g, 95% CI: 424.04-672.15; P < .001) than expectant management; there was no difference in the occurrence of miscarriages (5 studies with 7355 participants; RR: 1.57, 95% CI: 0.90-2.75; P = .11). Sensitivity analysis showed that all the results were stable and reliable, with the omission of 2 studies with serious risk of bias. CONCLUSION: Compared to expectant management, MPR of DCDA twin pregnancy to singleton prevents preterm birth and low birth weight, without increasing the risk of miscarriages. Regarding perinatal morbidity related to preterm birth, MPR can be reserved as a remediation measure to improve the perinatal outcomes of DCDA twin pregnancies.


Asunto(s)
Resultado del Embarazo , Reducción de Embarazo Multifetal , Adulto , Amnios/anatomía & histología , Corion/anatomía & histología , Femenino , Humanos , Embarazo , Embarazo Gemelar , Gemelación Dicigótica , Gemelos Dicigóticos , Espera Vigilante
9.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(6): 819-823, 2020 Jun 10.
Artículo en Chino | MEDLINE | ID: mdl-32564542

RESUMEN

Objective: To explore the genetic and environmental effects on alcohol intake. Methods: Data on 9 231 pairs of adult twins of the same sex was collected from the Chinese National Twin Registry (CNTR), between 2015 and 2018 and used in this study. Structural equation model was used to estimate the effects of genetic and environmental factors on alcohol intake. Results: A total of 9 231 pairs of twins were included in the analysis, of which 6 085 pairs were monozygotic (MZ). The average age of MZ was (36.91±13.07) years old, and males accounted for 56.80%. The average age of dizygotic twins (DZ) was (35.22±12.48) years old, and males accounted for 55.91%. There were 350 pairs of alcohol-drinking twins were with high-risk, accounting for 1.90% and another 367 pairs (1.99%) were with medium-risk. Alcohol-drinkers with medium-risk were affected by additive genetics, common and unique environmental factors, seen among the twins. The overall heritability appeared as 24.3% (95%CI: 0 to 56.8%). Furthermore, 50.7% of the variation (95%CI: 20.4%-79.0%) could be explained by the common environmental factors and 24.9% (95%CI: 18.3%-36.5%) by unique environmental factors. High-risk related drinking behavior was affected by both common and unique environmental factors. The common environmental component appeared as 75.6% (95%CI: 69.6%-80.8%) and unique environmental component as 24.4% (95%CI: 19.2%-30.4%), respectively. Gender difference was seen in the heritability of those with medium or high-risk drinking behaviors. The heritability of men was 30.8% (95%CI: 9.8%-53.5%), while in women it was mainly affected by the environment. Conclusion: Both alcohol drinkers with medium and high-risk drinking behaviors were mainly affected by the environment factors and gender. With the increase of drinking volume, the effect of environment on drinking behaviors became more obvious.


Asunto(s)
Consumo de Bebidas Alcohólicas/genética , Gemelos Dicigóticos/psicología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Gemelos Dicigóticos/estadística & datos numéricos
10.
Nat Ecol Evol ; 4(7): 987-992, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32393867

RESUMEN

Dizygotic twinning, the simultaneous birth of siblings when multiple ova are released, is an evolutionary paradox. Twin-bearing mothers often have elevated fitness, but despite twinning being heritable, twin births occur only at low frequencies in human populations. We resolve this paradox by showing that twinning and non-twinning are not competing strategies; instead, dizygotic twinning is the outcome of an adaptive conditional ovulatory strategy of switching from single to double ovulation with increasing age. This conditional strategy, when coupled with the well-known decline in fertility as women age, maximizes reproductive success and explains the increase and subsequent decrease in the twinning rate with maternal age that is observed across human populations. We show that the most successful ovulatory strategy would be to always double ovulate as an insurance against early fetal loss, but to never bear twins. This finding supports the hypothesis that twinning is a by-product of selection for double ovulation rather than selection for twinning.


Asunto(s)
Gemelación Dicigótica , Gemelos Dicigóticos , Femenino , Fertilidad , Humanos , Edad Materna
11.
Twin Res Hum Genet ; 23(1): 61-65, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32228740

RESUMEN

Twin data and the results generated by research are driven by the behavioral and physical attributes of twin participants. However, many investigators working with twin data have limited personal contact with actual twin-pairs. This situation may be limiting with respect to interpretation of results and formulation of new hypotheses. In an attempt to rectify this issue, key aspects of the interconnected lives of co-twins in three monozygotic male twin-pairs are presented. The section that follows includes a review of twin research on Kleine-Levin syndrome, political discussion, twin relationship quality and urinary cortisol level, and guidelines for determining sample sizes. The final part of this report presents twin-related news items relating to twins' same day deliveries, death of a twin Holocaust survivor, the Vindman twins, a twin festival in France and the tiniest twins on record.


Asunto(s)
Gemelos , Femenino , Francia , Vacaciones y Feriados , Holocausto , Humanos , Hidrocortisona/orina , Síndrome de Kleine-Levin/genética , Síndrome de Kleine-Levin/inmunología , Masculino , Política , Embarazo , Embarazo Gemelar , Sistema de Registros , Sobrevivientes , Gemelos/psicología , Gemelos Dicigóticos , Gemelos Monocigóticos
12.
Eur J Endocrinol ; 182(5): 473-480, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32229696

RESUMEN

Objective: Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases. Design: Prospective twin cohort study. Methods: We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto's thyroiditis, atrophic gastritis, celiac disease, Graves' disease, type 1 diabetes, vitiligo and Addison's disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation of data. Results: Co-aggregation was more pronounced in monozygotic twins (median HR: 3.2, range: 2.2-9.2) than in dizygotic twins (median HR: 2.4, range: 1.1-10.0). Heritability was moderate for atrophic gastritis (0.38, 95% CI: 0.23-0.53) but high for all other diseases, ranging from 0.60 (95% CI: 0.49-0.71) for Graves' disease to 0.97 (95% CI: 0.91-1.00) for Addison's disease. Conclusions: Overall, co-aggregation was more pronounced in monozygotic than in dizygotic twins, suggesting that disease overlap is largely attributable to genetic factors. Co-aggregation was common, and twins faced up to a ten-fold risk of developing diseases not present in their co-twin. Our results validate and refine previous heritability estimates based on smaller twin cohorts.


Asunto(s)
Autoinmunidad/fisiología , Enfermedad de Addison/genética , Autoinmunidad/genética , Enfermedad Celíaca/genética , Estudios de Cohortes , Femenino , Gastritis Atrófica/genética , Predisposición Genética a la Enfermedad/genética , Enfermedad de Graves/genética , Humanos , Masculino , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Gemelos Dicigóticos/genética , Gemelos Monocigóticos/genética
13.
Twin Res Hum Genet ; 23(1): 55-60, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32248882

RESUMEN

Using vital statistics in Japan (1995-2008), 154,578 live-born twin pairs (128,236 monozygotic [MZ] and 180,920 dizygotic [DZ]) were identified. The proportion of severe discordance among live-born twin births was twice as high in Japanese than Caucasian infants. There were 1858 MZ and 1620 DZ infant deaths. Computation of the relationship between infant mortality rate and birth weight discordance among the twins was performed. Discordance levels were classified into seven groups: <5%, five groups from 5-9% to 25-29%, and ≥30%.The mortality rate was significantly higher in MZ than DZ twins for discordances except at 5-9% and 10-14%. The lowest rate for MZ twins was at 5-9% (7.5 per 1000 live twins) and significantly increased from 10-14% (9.4) to ≥30% (83.4), while the lowest rate for DZ twins was at <5% (6.7), which significantly increased at 10-14% (8.0) and from 25-29% (12.1) to ≥30% (35.5). The relationship was also computed in two gestational age groups (<28 and ≥28 weeks). For births at <28 weeks, three discordances (after 20-24%) in MZ twins were associated with adverse mortality rate. For births at ≥28 weeks, the same relationship was obtained after 10-14% in MZ and after 20-24% in DZ twins. The relationship from 2002 to 2008 showed that the mortality rates significantly increased after 10-14% for both types of twins. In conclusion, five discordance levels in MZ and three levels in DZ twins were associated with adverse mortality rates.


Asunto(s)
Peso al Nacer , Mortalidad Infantil/etnología , Gemelos Dicigóticos/estadística & datos numéricos , Gemelos Monocigóticos/estadística & datos numéricos , Edad Gestacional , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Lactante , Mortalidad Infantil/historia , Japón
15.
Ann Hum Biol ; 47(3): 250-255, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32321309

RESUMEN

Background: Birth measures of twins are potentially influenced by sex of co-twin.Aim: To analyse the association between sex of co-twin and birth weight, length and ponderal index in twin infants from Yucatan, Mexico.Subjects and methods: A total of 2057 twin pairs born during 2008-2017 were analysed. Female-female (F-F), male-male (M-M) and male-female (M-F) twin pair types were defined. Multiple linear regression models were used to analyse the association of (1) being female from M-F pairs and birth measures among overall female infants (M-F and F-F), and (2) being male from M-F pairs and birth measures among overall male infants (M-F and M-M). The length of gestation and mothers' age and level of education were used as covariates.Results: Models showed that being male from M-F pairs was associated with increases of 81 g in birth weight and 0.61 cm in length, compared to males from M-M pairs, and being female from opposite-sex pairs was associated with increases of 0.36 cm in length, compared to females from same-sex pairs.Conclusions: Males from M-F pairs show greater birth size than males from same-sex pairs, which supports the hypothesis that birth measures of twins are influenced by sex of the co-twin.


Asunto(s)
Peso al Nacer , Gemelos Dicigóticos/estadística & datos numéricos , Femenino , Humanos , Recién Nacido , Masculino , México , Factores Sexuales
16.
Arch Dis Child ; 105(9): 864-868, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32156695

RESUMEN

OBJECTIVES: To assess evidence supporting the view that 'low fibre causes childhood constipation'. DESIGN: Triangulation integrated three approaches: a systematic review NICE guideline CG99 examining effectiveness of increasing fibre; a cohort study, Avon Longitudinal Study of Parents and Children (ALSPAC), to assess if constipation (or hard stools) can precede fibre intake at weaning; and a literature search for twin studies to calculate heredity. SETTING: CG99 examined the literature regarding the effectiveness of increasing fibre. ALSPAC asked parents about: hard stools at 4 weeks, 6 months and 2.5 years and constipation at age 4-10 years, as well as fibre intake at 2 years. Twin studies and data from ALSPAC were pooled to calculate concordance of constipation comparing monozygotic and dizygous twin pairs. PARTICIPANTS: CG99 reported six randomised controlled trials (RCTs). ALSPAC hard stool data from 6796 children at 4 weeks, 9828 at 6 months and 9452 at 2.5 years plus constipation data on 8401 at 4-10 years were compared with fibre intake at 2 years. Twin studies had 338 and 93 twin pairs and ALSPAC added a further 45. RESULTS: Increasing fibre did not effectively treat constipation. Hard stools at 4 weeks predated fibre and at 6 months predicted lower fibre intake at 2 years (p=0.003). Heredity explained 59% of constipation. CONCLUSIONS: RCTs indicate that increasing fibre is not an effective treatment for constipation in children. Hard stools can precede and predict later fibre intake. Genetic inheritance explains most childhood constipation. Extended treatment with stool softeners may improve fibre intake and limit long-term damaging sequelae of constipation.


Asunto(s)
Estreñimiento/etiología , Fibras de la Dieta/deficiencia , Adolescente , Niño , Preescolar , Estreñimiento/epidemiología , Estreñimiento/genética , Fibras de la Dieta/administración & dosificación , Enfermedades en Gemelos/epidemiología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Encuestas y Cuestionarios , Gemelos Dicigóticos , Gemelos Monocigóticos
17.
Twin Res Hum Genet ; 23(1): 33-38, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32209144

RESUMEN

Life-course experiences have been postulated to program hypothalamus-pituitary-adrenal (HPA) axis activity, suggesting that HPA axis activity is, at least partially, stable over time. Yet, there is paucity of data on the long-term stability of cortisol production and metabolism. We performed a prospective follow-up study in twins recruited from a nationwide register to estimate the stability of cortisol production and metabolism over time, and the contribution of genetic and environmental factors to this stability. In total, 218 healthy mono- and dizygotic twins were included. At the ages of 9, 12 and 17 years, morning urine samples were collected for assessment (by gas chromatography-tandem mass spectrometry) of cortisol metabolites, enabling the calculation of cortisol metabolite excretion rate and cortisol metabolism activity. Our results showed a low stability for both cortisol metabolite excretion rate (with correlations <.20) and cortisol metabolism activity indices (with correlations of .25 to .46 between 9 and 12 years, -.02 to .15 between 12 and 17 years and .09 to .28 between 9 and 17 years). Because of the low stability over time, genetic and environmental contributions to this stability were difficult to assess, although it seemed to be mostly determined by genetic factors. The low stability in both cortisol production and metabolism between ages 9 and 17 years reflects the dynamic nature of the HPA axis.


Asunto(s)
Glucocorticoides/metabolismo , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Adolescente , Niño , Cromatografía de Gases , Cortisona/metabolismo , Cortisona/orina , Citocromo P-450 CYP3A/metabolismo , Femenino , Estudios de Seguimiento , Interacción Gen-Ambiente , Estudios de Asociación Genética , Glucocorticoides/orina , Humanos , Hidrocortisona/orina , Sistema Hipotálamo-Hipofisario/enzimología , Estudios Longitudinales , Masculino , Sistema Hipófiso-Suprarrenal/enzimología , Estudios Prospectivos , Sistema de Registros , Espectrometría de Masas en Tándem , Gemelos Dicigóticos , Gemelos Monocigóticos/genética
18.
Twin Res Hum Genet ; 23(1): 51-54, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32209150

RESUMEN

Dichorionic diamniotic (DCDA) twin pregnancies after single blastocyst embryo transfer have been reported recently, although a blastocyst ovum is generally believed to divide into monochorionic twin pregnancy. We investigated the incidence of DCDA twin pregnancy after single blastocyst embryo transfer and their zygosity. This prospective cohort study included 655 consecutive twin pregnancies that were managed from 2006 to 2014 at our institution. Chorionicity and amnionicity were determined using first-trimester ultrasonography and/or placental pathology. Zygosity was analyzed if the cases were DCDA twins after single blastocyst embryo transfer. Among 655 twin pregnancies, there were 348 DCDA cases, 295 monochorionic diamniotic (MCDA) cases and 12 monochorionic monoamniotic cases. Single blastocyst embryo transfer was performed in 43 cases. Six out of the 43 (14%) cases involved DCDA twin pregnancies and the other 37 cases involved MCDA twin pregnancies. Three DCDA twins born after single blastocyst embryo transfer, wherein frozen embryo transfer (FET) was performed in the natural cycle, were dizygotic, and the other three cases, wherein FET with hormone replacement therapy was performed, were monozygotic. DCDA twin pregnancy occurred in 14% (7% for monozygotic and 7% for dizygotic) of twin pregnancies after single blastocyst embryo transfer cases.


Asunto(s)
Amnios/diagnóstico por imagen , Corion/diagnóstico por imagen , Gemelos Monocigóticos/estadística & datos numéricos , Adulto , Amnios/crecimiento & desarrollo , Blastocisto , Corion/crecimiento & desarrollo , Estudios de Cohortes , Transferencia de Embrión , Femenino , Humanos , Embarazo , Primer Trimestre del Embarazo , Estudios Prospectivos , Gemelos Dicigóticos/genética , Gemelos Dicigóticos/estadística & datos numéricos , Gemelos Monocigóticos/genética , Ultrasonografía Prenatal
19.
Behav Genet ; 50(2): 127-138, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32040643

RESUMEN

The univariate bootstrap is a relatively recently developed version of the bootstrap (Lee and Rodgers in Psychol Methods 3(1): 91, 1998). DeFries-Fulker (DF) analysis is a regression model used to estimate parameters in behavioral genetic models (DeFries and Fulker in Behav Genet 15(5): 467-473, 1985). It is appealing for its simplicity; however, it violates certain regression assumptions such as homogeneity of variance and independence of errors that make calculation of standard errors and confidence intervals problematic. Methods have been developed to account for these issues (Kohler and Rodgers in Behav Genet 31(2): 179-191, 2001), however the univariate bootstrap represents a unique means of doing so that is presaged by suggestions from previous DF research (e.g., Cherny et al. in Behav Genet 22(2): 153-162, 1992). In the present study we use simulations to examine the performance of the univariate bootstrap in the context of DF analysis. We compare a number of possible bootstrap schemes as well as more traditional confidence interval methods. We follow up with an empirical demonstration, applying results of the simulation to models estimated to investigate changes in body mass index in adults from the National Longitudinal Survey of Youth 1979 data.


Asunto(s)
Interpretación Estadística de Datos , Genética Conductual/métodos , Modelos Estadísticos , Adolescente , Adulto , Índice de Masa Corporal , Peso Corporal/genética , Intervalos de Confianza , Femenino , Humanos , Estudios Longitudinales , Masculino , Modelos Genéticos , Fenotipo , Análisis de Regresión , Medio Social , Gemelos Dicigóticos/genética , Gemelos Monocigóticos/genética , Adulto Joven
20.
Nat Commun ; 11(1): 709, 2020 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-32024844

RESUMEN

Human visual cortex contains discrete areas that respond selectively to specific object categories such as faces, bodies, and places. A long-standing question is whether these areas are shaped by genetic or environmental factors. To address this question, here we analyzed functional MRI data from an unprecedented number (n = 424) of monozygotic (MZ) and dizygotic (DZ) twins. Category-selective maps were more identical in MZ than DZ twins. Within each category-selective area, distinct subregions showed significant genetic influence. Structural MRI analysis revealed that the 'genetic voxels' were predominantly located in regions with higher cortical curvature (gyral crowns in face areas and sulcal fundi in place areas). Moreover, we found that cortex was thicker and more myelinated in genetic voxels of face areas, while it was thinner and less myelinated in genetic voxels of place areas. This double dissociation suggests a differential development of face and place areas in cerebral cortex.


Asunto(s)
Modelos Genéticos , Corteza Visual/diagnóstico por imagen , Corteza Visual/fisiología , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Memoria a Corto Plazo , Experimentación Humana no Terapéutica , Estimulación Luminosa , Gemelos Dicigóticos , Gemelos Monocigóticos
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