bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of Antepartum Uterine Activity and Cervical Change in Twin Gestation
Authors: Newman R. B. , Ellings J. M. , O'Reilly M. M. , Brost B. C. , Miller M. C. , Gates D. 
Published: July 2016

Objective. To determine the correlation between quantitative measurements of antepartum uterine activity and cervical change twin gestations.Methods. Forty women from our Twin Clinic constituted the study group. Participants had a cervical examination each week between 20 and 37 weeks gestation and a cervical score (CS) was calculated as follows: CS = cervical length (cms)-cervical dilation (cms) at the internal os. The women also performed blinded home uterine activity monitoring (HUAM) for a mean of 7.0+3.0 hrs/wk (+SD). Uterine activity was expressed as mean number of contractions/hour/week gestation based on the average of three independent reviewers. CS was determined by a single clinician unaware of the HUAM recordings. A significant change in the CS was defined as a reduction of at least 0.5 from the preceding week. Correlation coefficients were used to determine the association between uterine activity and change in the cervical score.Results. Twin pregnancy was characterized by a rise from 0.2 + .03 contractions/hr at 20 weeks to 3.2 + 2.4 contractions/hr at 37 weeks gestation. CS fell from a mean of 2.6 + 0.2 at 20 weeks to −2.1 + 0.9 at 37 weeks gestation. There was a significant negative correlation (−0.317, p<.0001) between increasing uterine activity and decreasing CS. There were significantly more (p <.002) contractions during the 7 days preceding a significant reduction in CS (3.3 + 3.5 contractions/hr) than when the CS was unchanged (1.6±1.5 contractions/hr).Conclusions. In twin gestations, an increasing frequency of uterine contractions is strongly correlated with quantifiable cervical change between 20-37 weeks gestation. Persistent daytime contraction frequencies of >3/hr represent a risk factor for cervical dilation and/or effacement.
The Twinning Rates and Epidemiological Characteristics of Births in Southeast Uttar Pradesh, India
Authors: Sharma K. 
Published: July 2016

AbstractBirth statistics over a period of 5 years were analyzed to study epidemiological characteristics of twinning in Southeast Uttar Pradesh, India. The data revealed higher incidence of breech twins (11.84% of all cotwins) as compared to breech single births (2.18%). But the perinatal mortality and caesarean section rates were similar in both twin and singleton pregnancies. The cumulative twinning rate over the studied period was 11.70 per 1000 live births. The MZ and DZ twinning rates were estimated respectively as 3.67 and 8.03 per mill. The mean maternal age of sampled mothers was 26.42 years with one standard deviation of 5.30 years. The twinning rate for mothers over 35 years of age was about four times higher than that in mothers younger than 20 years. Incidently, the twinning rate was the highest at parity four and a non-linear curve could more appropriately be fitted to the series of data. Seasonal variations were observed for both twin and singleton births. The highest frequency of births was observed from August through October. But seasonal index for twinning rate showed a clear bimodal distribution with peaks in April (223) and September (167).
Maternal and Neonatal Variables in Twins: an Epidemiological Approach
Authors: Campana M. A. , Roubicek M. M. 
Published: July 2016

AbstractPopulation studies on human twinning are scarce in Argentina. In order to analyze frequencies and certain maternal and neonatal variables related to twin births, we studied a series of 69.678 consecutive newborns with 500 g of weight and over, which occurred at a public hospital in the province Buenos Aires, during 14 years (1982-1995). The frequency of twin births (10 per 1000 deliveries) and sex ratio were similar to other studies reported in Caucasian population. Maternal age and order of gravity/parity were positively correlated with twinning rates, more markedly so in dissimilar sex-pairs. Stillbirths and neonatal deaths were more frequent in twins than in singletons, but less frequent when comparing groups of same weight. Congenital malformations were not found to be significantly more frequent in twins than in the total newborn population. However, their occurrence, predominantly in like-sexed pairs and the concordance for defect type in doubly affected same-sex pairs, suggests that monozygotic twinning carries an increased risk for malformation.
Cognitive Development and Behaviour in Very Low Birthweight Twins at Four Years
Authors: Dezoete J.A. , MacArthur B.A. 
Published: July 2016

AbstractThis study included two groups of 37 children, one of twins and the other singletons at 4 years of age. All subjects had birthweights under 1500 grams and individuals in the groups were matched for birth date, gender and birthweight. Except when parental socio-economic status was taken into account, no significant differences between twins and singletons were observed on any of the results ofThe Stanford-Binet Intelligence Scale, nor were there any when the twins and singletons were divided into groups with birthweights < 1000 grams and 1000 to 1499 grams. When cognitive scores were analysed in relation to socio-economic status, there were significant differences in the whole population between subjects in the high and low socioeconomic status groups, with higher mean scores for the former. Comparison of the twins and singletons with parents in the lower socio-economic status group did not produce any significant differences but in the case of the upper socio-economic status group the singletons scored significantly better that the twins in Quantitative Reasoning and on the Composite Score. No significant differences were demonstrated in the clinical assessment of speech, language or behaviour. So far as general life considerations and health were concerned only one significant difference was found and this was for the number of siblings born subsequently, with more born in the singleton families. This study did not provide support for the view that singletons and twins differ significantly in the areas considered.
Reducing Fetal Deaths in Multiple Births: Optimal Birthweights and Gestational Ages for Infants of Twin and Triplet Births
Authors: Luke B. 
Published: July 2016

AbstractThe objective of this study was to determine the birthweight and gestational age associated with the lowest fetal mortality for twins and triplets. The study design was a population-based analysis of all live births and fetal deaths in the US between 1983-88. Fetal mortality was compared by categories of birthweight and gestational age, for twins and triplets versus singletons, and within each plurality by the lowest rate compared to all other rates as relative risks ± 95% Cls. The overall versus lowest fetal death rate per 1,000 conceptions for singletons was 4.3 versus 0.9 at 3700-4000 g and 40-41 weeks; for twins, 15.5 versus 3.3 at 2500-2800 g and 36-37 weeks; and for triplets, 21.0 versus 5.2 at 1900-2200 g at 34-35 weeks. Beyond these plurality-specific lowest ranges, the risk of fetal death increased, more for twins than singletons, and most for triplets. To conclude, fetal death rates can be reduced by 75-80% with attainment of birthweight and gestational age within a plurality-specific ideal range.
The “Equal Environments Assumption” in MZ-DZ Twin Comparisons: an Untenable Premise of Psychiatric Genetics?
Authors: Pam A. , Kemker S.S. , Ross C.A. , Golden R. 
Published: July 2016

AbstractThe comparison of MZ-DZ twins in behavioral genetics has produced what seems like irrefutable evidence for the heritability of many psychiatric disorders. But such research depends on the validity of the EEA – the “equal environments assumption” – as an underlying premise. In this paper, several empirical studies which support the EEA are critically reviewed in terms of methodology and the way data has been processed in a mathematical model called “path analysis”. It turns out that studies investigating the EEA appear to be largely inadequate in terms of technique, as well as biased in the inferences drawn. Further, the “heritability” estimate – often taken to mean the influence of trait – specific genes – is merely a statistical abstraction derived from a matrix of correlations; this estimate encompasses many buried environmental effects so that “heritability” does not correspond to any underlying DNA structure. In conclusion, many MZ-DZ pedigree studies have dubious scientific value, given the non-viable premise of the EEA, as well as the misleading operational definition of what has been called “heritability”.
Embryologic Development and Monozygotic Twinning
Authors: Hall J.G. , Lopez-Rangel E. 
Published: July 2016

In 1875, Sir Francis Galton was the first to propose that by comparing the concordance of a specific trait or disorder in monozygotic (MZ) twins (assumed to be genetically identical) and dizygotic (DZ) twins (which were assumed to be as similar or as different as any other pair of sibs), it would be possible to distinguish between environmental and heritable effects. DZ twins are derived from the fertilization of two eggs by two sperm. MZ twins are the result of the fertilization of one egg by one sperm that then divides to form two embryos.Genetic research has made amazing progress since 1875. Advances in molecular DNA techniques and developmental genetics have made it possible to differentiate unequivocally between MZ and DZ twins [1, 14]. It is in this new light that this manuscript will review the recent knowledge about twins and the twinning process.The incidence of DZ twins differs between population [11, 18]. A DZ twin birth in North America is estimated to occur 9–11 times in every 1000 live births or 1 in 100 births; i.e. 1 in every 50 people is a DZ twin.The DZ twinning rate is closely related to maternal age, parity, height, weight and gonadotropin levels. An increased DZ twinning rate is seen with increasing maternal age and peaks around 35–39 years; higher parity is also associated with a higher DZ twinning rate [19]. Tall heavy women are more likely to give birth to DZ twins than short thin women. A higher incidence of DZ twins has also been reported with the use of new reproductive techniques.
Imprinting and Transgenerational Modulation of Gene Expression; Human Growth as a Model
Authors: Pembrey M. 
Published: July 2016

AbstractIt is proposed that transgenerational modulation of gene expression might be possible, if the metabolic response of the parent to some physiological or social stress modified imprint setting. Transcription regulators could theoretically mediate this process. The nature of imprinted genes poised, as it were, between a transcriptionally active and silent state, makes them good candidates for incorporation into the evolution of transgenerational adaption systems where coordinated changes in gene expression over the generations is a selective advantage. The coordination of human fetal (head) growth with the existing size of the mother's pelvis is suggested as just such a circumstance. The reduced birth weight of Dutch babies where their grandmothers suffered acute starvation in mid pregnancy, supports the notion of transgenerational adaption to nutrition, as does the secular change (increase) in child growth over the last century. The recent indication that there may be functional polymorphism in the imprinting of the human IGF2 and IGF2R genes suggests these ideas could be explored using association studies at the population and individual level.
Aneuploid Correction and Confined Placental Mosaicism
Authors: Simoni G. , Sirchia S. M. , Fraccaro M. 
Published: July 2016

Uniparental disomy (UPD) can be caused by various genetic mechanisms such as gamete complementation, chromosome duplication in a monosomic zygote or postzygotic aneuploid correction. This latter mechanism has been recently well documented in human reproduction and seems to be strictly related to placental mosaicism. We have therefore studied some aspects of confined placental mosaicism (CPM) which are useful to clarify one of the most common sources of UPD in humans.Abnormal distribution of chromosomes in postzygotic mitotic cell divisions may result in a mosaic condition with two or more cell lines showing different chromosome constitutions. The effects on fetal phenotype and pregnancy development depend on the chromosomes involved, the distribution of the abnormal cells among tissues and on the precise stage at which chromosome mutation occurs.As shown in Fig. 1, when the mutational event occurs in the blastocyst, prior to the differentiation of embryonic and chorionic compartments, the mosaicism is found in both the placental and fetal tissues. In contrast, when the chromosome mutation occurs at a later stage, after embryonic and chorionic compartment separation, the abnormal cells may be confined to the placenta or to the embryo, and are not necessarily found in both.
The IPW Gene is Imprinted and is not Expressed in the Prader-Willi Syndrome
Authors: Wevrick R. , Kerns J.A. , Francke U. 
Published: July 2016

Since the original description of the Prader-Willi syndrome (PWS) in 1956 [1], and the recognition of the involvement of the proximal region of chromosome 15 in this disorder [2], understanding of the molecular basis of the genetic defect in PWS has progressed rapidly. A set of clinical criteria has been defined [3], although the diagnosis on clinical grounds alone remains difficult in the first year of life. Research has focussed both on improving the diagnostic molecular and cytogenetic tests for PWS and on identifying and defining the functions of genes whose expression is altered in this neurobehavioral disorder. Furthermore, this region is known to be subject to genomic imprinting effects, so that expression of genes involved in PWS is expected to be exclusively from the paternal allele.A critical step in the definition of the region containing such genes was the identification of a subset of unusual patients affected with either PWS or the Angelman syndrome, which also involves a gene or genes in the proximal region of chromosome 15. These unique patients, who have chromosome 15 translocations or deletions, helped to narrow the critical region to an interval containing less than 500 kb of DNA [4-6] (Fig. 1). As will be discussed, below, regulatory elements exist in this 500 kb region which alter the expression of genes located outside this interval [7, 8].
A New Case of Beckwith-Wiedemann Syndrome with an 11p15 Duplication of Paternal Origin [46,XY,-21,+der(21), t(11;21)(p15.2;q22.3)pat]
Authors: Krajewska-Walasek M. , Gutkowska A. , Mospinek-Krasnopolska M. , Chrzanowska K. 
Published: July 2016

AbstractWe present a new case of 11p15 duplication (trisomy 11p15) in a boy [46,XY,-21,+der(21), t(11;21)(p15.2;q22.3)] suffering from Beckwith-Wiedemann syndrome (BWS), whose phenotypically normal father carries a balanced translocation between chromosomes 11 and 21[46,XY, t(11;21)(p15.2;q22.3)]. The paternal grandmother has the same balanced translocation and is also clinically normal. BWS was suspected when the boy was 6 months old because of gigantism, macroglossia, visceromegaly, ear lobe creases and abdominal distention. Apart from the characteristic BWS phenotype, the boy has other features which are almost exclusively observed in 11p trisomy (high forehead with frontal upsweep of hair, wide central nose bridge, slightly beaked nose, chubby cheeks and severe mental retardation). So far, at least eight cases of 11p15 duplication have been described as patients with BWS. In six of these, the duplication was due to inheritance of a translocated or rearranged paternal chromosome. This was also the case in our patient. In the two other previously published cases, the 11p15 duplications were de novo, but in one of these, DNA analysis has subsequently shown that the duplication was of paternal origin. We discuss our observations in relation to the above-mentioned previous cases of 11p15 duplication and the possible role of genomic imprinting in the etiology of BWS.
A Case of Angelman Syndrome Arising as a Result of a De Novo Robertsonian Translocation
Authors: Ramsden S. , Gaunt L. , Seres-Santamaria A. , Clayton-Smith J. 
Published: July 2016

AbstractA male child has been identified with Angelman syndrome. He has been shown to carry a de novo Robertsonian 15/15 translocation where both chromosome 15s have been derived from the father. Consequently the disease in this instance is due to paternal uniparental disomy.
The Childhood Growth of Twin Children
Authors: Luke B. , Leurgans S. , Keith L. , Keith D. 
Published: July 2016

AbstractThe objective of this study was to assess the childhood growth of twin children in terms of the effects of intrauterine growth retardation (IUGR) and discordancy at birth on the incidence and severity of stunting and discordancy in current height and weight. The study was part of a cross-sectional field project conducted at the Annual Twins Days Festival in Twinsburg. Ohio, USA, during 1990, 1991, and 1993, and including all twin children between 2 and 12 years of age. Mothers of twins were interviewed regarding their children's birthweights and gestational age; the twin children were measured for their current heights and weights. The study population included 990 twin children, including 555 boys and 435 girls, of which there were 254 boy pairs and 194 girl pairs. Birthweight for gestational age and current weight and height were each converted into Z-scores and characterized as severe (Z-score <−2,0), or moderate IUGR or stunting (Z-score > −2.0 and < −1.2). For the present study discordancy in birthweight, and current height and weight was calculated for like-gender twin pairs. Only twin children with severe IUGR at birth showed an increased risk of stunting in their current height or weight, and this risk was only for moderate, not severe, stunting. Boy twins with severe IUGR at birth were at increased risk of moderate stunting in their current weight (OR 2.67, 95% CI 1.55, 4.58, P = 0.002), while girl twins with severe IUGR at birth were at increased risk of moderate stunting in their current height (OR 4,09, 95% CI 1.49, 10.99, p = 0.003). Among like-gender twin pairs, there were no differences in mean or categories of birthweight or current weight discordancy, but boy twin pairs did show a significantly greater proportion of current weight discordancy compared to girl twin pairs (p = 0.005). Overall, there was a significant tendency for differences in height and weight between like-gender twin pairs to disappear over time, with the effect being greater for boy twin pairs. We conclude from these findings that twin children tend to overcome growth retardation and discordancy present at birth, and although children who had severe IUGR or discordancy at birth were more likely to have some residual moderate stunting or discordancy in height or weight, they still tended to be within normal values for their gender and current age.
Mutations in Fucosidosis Gene: a Review
Authors: Tiberio G. , Filocamo M. , Gatti R. , Durand P. 
Published: July 2016

AbstractFucosidosis is an autosomal recessive disorder caused by a deficiency of alpha-L-fucosidase. Up to now 79 cases have been described and several others identified but not yet published. The higher incidence of the disease is in Italy, where nearly 20 patients have been identified. Fourteen disease-causing mutations have been detected and four of them, Q422X, G60D, E375X, P141fs are present in more than 70% of the forty patients studied. In Italian patients, only seven mutations have been described and P141fs and G60D mutations are present in more than 50% of the cases. The P141fs mutation is absent in other ethnic groups. It has been impossible to establish genotype-phenotype correlation so far and the clinical variability of the disease cannot be explained only by genetic heterogeneity.
Twin-to-twin Transfusion Syndrome Type III - Case Report of an Intrauterine Death in Monochorionic Pregnancy
Authors: Biskup I. , Malinowski W. 
Published: July 2016

AbstractThe acute form of twin-to-twin transfusion syndrome is caused by rapid transfer of blood from one of the twins to another via placental anastomoses. Usually, this only occurs during the second stage of labour as a result of a sudden relative rise of blood pressure in one of the fetal circulations. This can result in the sudden intrauterine death of a fetus (or both, as in our case). Currently, there is no reliable means of identifying such an at-risk pregnancy by means of ultrasound antenatally. We would classify this as TTTS Type III.
Laterality Effects In Twins
Authors: Meshkova T.A. 
Published: July 2016

AbstractThe laterality effects in 10 symmetrical EEG derivations in twins (20 MZ and 20 DZ pairs with a mean age of 20.5 years) were examined. The quantitative and qualitative analyses gave the following results: (1) cotwins in the MZ and DZ pairs differed particularly in the intensity of asymmetry for EEG parameters — one was more asymmetrical than the other; (2) among the MZ twins there were no “mirror” pairs (opposite asymmetry of the EEG), even where opposite-handedness existed. For example, a right-handed twin had an asymmetrical EEG, while the other, a left-hander, had a symmetrical one; (3) the most asymmetrical EEG was in the temporal derivations showing a more active left hemisphere; and, (4) there was no evidence of genetic influence in the intensity of EEG asymmetry.
Twinning Rates in Japan, 1951-1990
Authors: Imaizumi Y. 
Published: July 2016

AbstractTwinning rates in all of Japan for 1951-1968 and 1974-1990 were analyzed using data from vital statistics of Japan. The twinning rate per 1,000 births was 6.43 in 1951 and remained nearly constant until 1968, then decreased to 5.79 in 1974 and gradually increased to 7.00 in 1990. The MZ twinning rate increased slightly up to 1966, but decreased thereafter, whereas the DZ rate declined over the entire period. As for maternal age, the DZ rate increased up to the age group 35-39 and decreased thereafter. The same tendency is seen in the MZ rate, but the maternal age effect is less marked than in DZ twins. The same tendency is also seen in the overall rate for 1975-1985. As for geographical variations, the MZ and DZ rates were computed in each prefecture for 1955-1959 and in 1974. The DZ rate increased from a low level in the southwest of Japan to a high level in the northeast for both periods, whereas the MZ rate was rather constant in 1974 throughout Japan. As for seasonal variation, the highest rates per 1,000 births for MZ(4.56) and DZ(2.20) twins were seen in April, with the lowest rate in September (3.69) for MZ twins and in July (1.71) for DZ twins.