bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Analysis of Marital Interaction in Cross-Sectional Twin Data
Authors: Heath A.C. 
Published: July 2016

AbstractThe effects on twin data of social interaction between spouses is examined. When social interaction leads to an increase in marital resemblance (eg through reciprocal imitation), the variance of married individuals is increased, compared to the variance of unmarried individuals. Furthermore, the expected correlations between concordant married twin pairs will be lower than the expected correlations between concordant unmarried twin pairs, with the discordant twin correlations being intermediate in value. It is therefore possible, in principle, to detect the effects of marital interaction without using either longitudinal data or data on spouse pairs. However, to be detectable in twin data, marital interaction must be strong, or must exhibit marked asymmetry of effects between males and females. Genotype × environment interaction can also produce heterogeneity of correlation between concordant married, discordant, and concordant unmarried twin pairs, when genetic and environmental effects interact with marital status. However, this will usually produce increased estimates of the genetic component of variance in unmarried twins, whereas marital interaction produces increased genetic variance in married twins.
NOR Variability in Twins
Authors: Weltens R. , Kirsch-Volders M. , Hens L. , Defrise-Gussenhoven E. , Susanne C. 
Published: July 2016

AbstractThe number of AgNOR (NOR+) and the amount of AgNOR (NORM+) were analysed by means of two multilevel analyses of variance in a total of 12 twin pairs: 3 female and 4 male MZ and 5 male DZ pairs. In the first analysis, only zygosity was controlled; in the second, chromosome types D and G were controlled as well as the interaction between chromosome type and zygosity. For NOR+ and NORM+, when chromosome types D and G are not distinguished, the within-pair variance is greater, though not significantly, in DZ than in MZ pairs; but it is highly significantly greater when chromosome type (D or G type) is under control. This confirms an important genetic determination of NOR+ and NORM+ when in the ANOVA model the D and G types are controlled. However, nongenetic factors also influence the Ag-NOR patterns, but not enough to conceal the genetically defined rDNA pattern. Indeed, about 50% of the cells transcribe their rDNA in a way not closely dependent on the rDNA background and significant intrapair differences of NOR+ pattern exist in MZ twins.
Premature Contractions: Are They Caused by Maternal Standing?
Authors: Schneider K.T.M. , Huch A. , Huch R. 
Published: July 2016

AbstractIn 33 out of 51 women studied in late gestation, the uterus was found to phasically compress the pelvic vessels and impede the venous blood flow during quiet standing. This caused a reduction of the cardiac stroke volume with resultant reduction of systemic blood pressure and a compensatory increased heart rate (range of increases 9-51 beats/min). In all cases uterine contractions (mostly subclinical) coincided with the phase of circulatory readjustment. Apparently, the contracting uterus, by changing its position and/or shape, relieves the venous obstruction and prevents decompensation. In the women displaying the uterine compression syndrome (UCS), uterine activity was markedly increased in standing compared to the left recumbent position.It was also investigated whether the UCS appeared more often and earlier in gestation in women with twins. In all 9 women with twin pregnancies (mean gestational age 28 5/7 weeks) the UCS associated with uterine contractions was apparent in the standing posture. Although at present no definite conclusions can be reached on the effect on the cervix of these contractions, quiet standing especially in twin pregnancies seems to provoke an increased uterine activity and should therefore be avoided.
Discordant Monozygotic Twins with Trisomy 13
Authors: Loevy H.T. , Miller Marilyn , Rosenthal Ira M. 
Published: July 2016

AbstractMonozygotic twins with typical trisomy 13 are reported. Despite an identical karyotype, the twins were dimorphic for the presence of an omphalocele. Reasons for the rarity of MZ twins with trisomy 13 are presented. It is suggested that the presence of a chromosomal abnormality in MZ twins may predispose to dimorphism.
Arterial Blood Pressure - The Pattern of Change in Twin Pregnancies
Authors: Campbell D.M. , Campbell A.J. 
Published: July 2016

AbstractAn epidemiological study of all primigravid twin pregnancies delivered in Aberdeen between 1950 and 1969 was performed to determine the pattern of arterial blood pressure changes. There is a greater fall from non-pregnant levels in diastolic blood pressure by mid pregnancy and a greater rise of diastolic pressure by delivery. These changes are independent of age, body size and rate of weight gain during pregnancy. The expected increased incidence of proteinuric pre-eclampsia is also independent of rate of weight gain when defined for twin pregnancies.
Twin Pregnancies: An 11-Year Review
Authors: Grothe W. , Rüttgers H. 
Published: July 2016

AbstractFrom 1971 to 1981, 16752 women were delivered at the University Women's Clinic in Heidelberg; 228 of these were twin pregnancies (1.36%). The relationships between sex, gestational age, birthweight, mortality, and fetal outcome were investigated. For the reason of grading, so-called χ2 curves are used. These curves show the strength and the course of relationship between two parameters. Mortality of the twin (8.3%) depended on birthweight and on sex of the infant, but not on the mode of delivery. All twins were ‘small-for-date’ (25th weight percentile of single births). Starting at the 35th week of gestation, the increase in weight decelerated additionally. So, immaturity as well as twin-related factors led to the high mortality rate for twins. Fetal outcome was evaluated in respect to the birthweight and to the delivery interval.
Seasonality in Early Loss of One Fetus Among Twin Pregnancies
Authors: Nakamura I. , Uno M. , Io Y. , Ikeshita I. , Nonaka K. , Miura T. 
Published: July 2016

AbstractUltrasonographic examinations were performed on 519 pregnant women in the first trimester at three hospitals in Tokyo from August 1985 to March 1987. Among 519 women, two fetal heart movements (FHMs) were comfirmed in six cases. In two of these six cases, one of two FHMs disappeared two weeks later, and these were considered the “vanishing twin”. In eight cases among those with ultrasonographic image of echo-free-space (EFS) in the uterus, the observed EFS was considered to be a probable empty gestational sac (GS-like-EFS-image). Seven of eight GS-like-EFS-images were observed in October-December (p < 0.01) and two “vanishing twin” cases were also observed in the same season. Spontaneous abortion occurred in 11 cases and these were also more frequently observed in October-November (p < 0.05). Some abortive factor is supposed to have prevailed in October-December. All six women having twin fetuses (including the “vanishing twin” cases) were born in January-May (p < 0.05) and those having GS-like-EFS-images or terminating their pregnancy in spontaneous abortion were also born more frequently in the same season. Twin-prone and abortion-prone characteristics of the women born in this season are considered.
Fetal Deaths with Birth Defects Among Japanese Multiples, 1974
Authors: Imaizumi Y. , Asaka A. , Inouye E. 
Published: July 2016

AbstractSource of data is “Survey on Socio-Economic Aspects of Vital Events – Plural Births in 1975”, including 12,392 twin pairs, 124 triplet sets, 7 quadruplet sets and 1 quintuplet set. Feal deaths were 3,285 for twins, 141 for triplets, 17 for quadruplets, and 5 for quintuplets, among which the numbers of birth defects were 78, 3, 0, and 0, respectively. Concordant twin pairs with the same category of birth defect were 20 among 56 pairs (0.36). As for the remaining 36 pairs, 2 pairs had different category of birth defects, 27 pairs had liveborn cotwins, and 7 pairs were both fetal deaths among which a twin had birth defect. The second-born twins had birth defects more frequently than the first-born twins among fetal deaths (28 vs 6).
Transfusion Syndrome in a Triplet Pregnancy
Authors: Pons J.C. , Olivennes F. , Fernandez H. , Ramdin I. , Mayenga J.M. , Bessis R. , Papiernik E. 
Published: July 2016

AbstractA case is reported of a transfusion syndrome in a triplet pregnancy with intrauterine death of two of the fetuses. This is an exceptional occurrence in a triplet pregnancy and raises the problem of the management of multiple pregnancies associated with the death of one or more of the fetuses. The problem of the method of delivery and the complications arising in triplet dizygotic pregnancies is discussed.
Quantitative Genetic Analysis of Longitudinal Trends in Height: Preliminary Results from the Louisville Twin Study
Authors: Phillips K. , Matheny A.P. 
Published: July 2016

AbstractA preliminary series of quantitative genetic models was applied to a subset of longitudinal height data, spanning birth to maturity, gathered from twin families in the Louisville Twin Study. Descriptive Cholesky factor parameterization was found to give more satisfactory results than did a system of constraints based on a model of developmental transmission of a time-constant and time-specific factors. The results from application of two autosomal sex-limitation models are contrasted with those from a model specifying both autosomal and sex-chromosomal patterns of inheritance. The latter model was more conducive to parameter reduction. Although these models do not constitute conclusive tests of autosomal sex-limitation versus sex-linkage, the more parsimonious model is consistent with previous research suggesting a stature locus on the long arm of the Y chromosome. Heritability of height is estimated at about 90% or greater from 6 years of age on. Substantial and fairly constant longitudinal genetic correlations are found from 3 years of age on. Shared environmental effects unrelated to parental height were seen for birth length, corrected for gestational age, to height at 3 years of age, but these are not satisfactorily differentiated from possible twin effects in the present sample. The genetic consequences of assortative mating are emphasized since failure to take assortment into account can lead to overestimation of shared environmental effects and under-estimation of genetic effects. The results indicate that about 20% of within-gender variability for mature height can be attributed to the genetic consequences of assortment, even though the phenotypic marital correlation of 0.22 is quite modest. The importance of testing the assumption of multivariate normality underlying the application of the method of maximum-likelihood is also highlighted.
Relationship Between Blood Uric Acid Level and Personality Traits
Authors: Ooki S. , Yamada K. , Asaka A. 
Published: July 2016

AbstractThe present study deals with the relationship between blood uric acid level and human behavior. Subjects were 37 MZ and 7 DZ twins aged from 18 to 45 years. In males, blood uric acid level increased with age, while it decreased with age in females. Blood uric acid level was corrected and standardized using regression lines separately for males and females. The distribution of standardized uric acid level corresponded well with the theoretical curve of normal distribution. The intraclass correlation coefficient for standardized uric acid level was r = 0.370 (P < 0.05) for the 37 MZ twins, but not significant for the 7 DZ twins. These findings suggest that blood uric acid level is genetically controlled. By the analysis of 12 personality traits in YG (Yatabe-Guilford) character test, it was revealed that “General activity” was more controlled by genetically than environmentally. In the evaluation of the correlation between standardized uric acid level and the YG 12 personality traits, significant correlation was observed in “Lack of agreeableness” and “Rhathymia”. Since these two personality traits include the factor of “activity”, it is concluded that the plasma uric acid level and activity in a broader sense are under genetic control. This conclusion is consistent with the generally accepted view that persons with high uric acid level are more active and energetic than those with low level.
Congenital Malformations in Twins: A Population Study
Authors: Källén Bengt 
Published: July 2016

AbstractMalformations in twins were studied with the use of a Medical Birth Registry covering nearly all births in Sweden, 1973-1981. A total of 15,427 infants marked twins were identified and the malformation diagnoses were analyzed, comparing rates with the overall rates in the same data source. Problems in ascertainment and interpretation are discussed. No excess of neural tube defects was seen, but hydrocephaly was diagnosed more often in twins than in singletons. This can be partly, but not completely, explained by a higher rate of low-weight infants among twins. An excess was noticed in twins in the rates of cardiac defects, spine defects, gut atresias – notably esophageal and anal atresia – and severe kidney malformations. These are components of the so-called VACTERL syndrome – the last component (limb reductions) being more common in twins than in singletons, though statistical significance was not reached. A relation between monozygotic twinning and this syndrome is tentatively suggested.
Metric Analyses of the Teeth and Faces of South Australian Twins
Authors: Townsend G.C. , Brown T. , Richards L.C. , Rogers J.R. , Pinkerton S.K. , Travan G.R. , Burgess V.B. 
Published: July 2016

AbstractProcedures are described for the acquisition and analysis of data in a study of the dental and facial characteristics of South Australian twins. Comparisons of the mesiodistal diameters of maxillary incisors in MZ and DZ twins revealed heterogeneity of total variances and evidence of inequality of mean values for some dimensions between MZ and DZ twins. Previous estimates of heritabilities for tooth size, relying on classical assumptions in twin research, may be exaggerated. A preliminary analysis of facial shape was undertaken using a procedure for shape matching based on a least squares fit of homologous coordinates. There was evidence of mirror-imaging in some MZ twin pairs and differences in facial asymmetry between male and female DZ twins. Future extensions of the study using methods for three-dimensional shape analysis are described.
Preterm Deliveries in Twin Pregnancies in Oxford
Authors: Watson P. , Campbell D.M. 
Published: July 2016

AbstractThe incidence of preterm delivery among twin maternities in Oxford between 1973 and 1983, was 39.4%. Preterm delivery was more common in MZ than DZ twins, and this was associated with higher incidence of spontaneous rupture of the membranes associated with monozygosity.
Twin Studies of Coronary Heart Disease and Its Risk Factors
Authors: Berg Kare 
Published: July 2016

AbstractThe ongoing comprehensive study of the updated population-based Norwegian Twin Panel (like-sexed twin pairs born since 1915) has already given results of interest to the research on coronary heart disease and its risk factors. Significantly more dizygotic (DZ) than monozygotic (MZ) pairs are discordant for death between 40 and 60 years of age. Presumably, several of the cases must have been coronary heart disease deaths. In pairs where both members are alive, concordance rate for coronary heart disease before the age of 60 years is significantly higher in MZ than in DZ pairs. Concordance rate for reported hypertension is significantly higher in MZ than in DZ pairs. These findings are compatible with a significant genetic effect on premature death, coronary heart disease and hypertension.There is a strong genetic effect on serum level of apoB, apoA-I and apoA-II, a weaker effect on cholesterol level and a doubtful effect on triglyceride level. Genes belonging to several normal genetic polymorphisms may participate in the control of environmentally/dietary caused variability in lipid and lipoprotein parameters. The study of MZ twins that was conducted to detect these effects holds considerable promise for the detection of gene control of many kinds of quantitative parameters. Further work with this twin panel may provide more definite answers to several questions raised during the present investigation. Application of more sophisticated models for twin family analysis on several normal and pathological traits may be very informative. Also, this updated Norwegian Twin Panel should in the long run make it possible to estimate the predictive value for the second member of a twin pair of having a twin contracting coronary heart disease (or any other reasonably frequent disease) by a given age. Finally, the subsample that is subjected to extensive laboratory analyses will provide useful data for genetic linkage analyses since in many cases, offspring of two members of a MZ pair can effectively be considered as one single (more informative) sibship.
Twin Analysis as a Potential Tool for Examining Psychosocial Factors Associated with and Preceeding Smoking Behaviors
Authors: Pedersen N.L. , Floderus-Myrhed B. 
Published: July 2016

AbstractData from the young cohort of the Swedish Twin Registry are being used in an attempt to describe characteristics which distinguish among current, non- and ex- smokers prior to the development of a smoking habit versus those present after establishment of the habit (or lack of one). With twins as a sample of individuals, the psychosocial variables instability, extroversion, leisure activity, relative weight, alcohol, coffee and psycho-pharmaceutic drug use were examined jointly as predictors of current smoking status in multiple regression analyses. This phase was intended to replicate and expand upon earlier studies characterizing current, non- and ex-smokers. These analyses were then performed on MZ nonsmoking twin individuals who were classified on the basis of their cotwins' smoking status. Pattern of variation in the psychosocial variables across the groups of nonsmokers were similar to the pattern seen for current, ex- and nonsmokers. Characteristics in MZ nonsmokers which are predictive of their cotwins' smoking status may be interpreted as those present prior to development of a smoking habit. Selected results from these analyses will be presented.
Finnish Twins Reared Apart. IV: Smoking and Drinking Habits. A Preliminary Analysis of the Effect of Heredity and Environment
Authors: Kaprio J. , Koskenvuo M. , Langinvainio H. 
Published: July 2016

AbstractData on alcohol use and smoking habits was available from the 1975 questionnaire of the entire cohort. Prior to pairwise analyses, the data of individuals was compared to that of age-sex matched groups of pairs reared together. The early separated twins had a higer alcohol consumption, while for smoking only slight differences were observed compared to twins reared together. Probandwise concordance rates were computed from smoking status (ever smoker/never smoker), alcohol use (user/nonuser) and “heavy” drinking (half-bottle of spirits on one occasion at least once a month). The following results were obtained in those pairs with the environmental dissimilarity score > 15:
Cancer and Senescence: Is There a Biological Link?
Authors: Burch P.R.J. 
Published: July 2016

AbstractIt is shown that sex- and age-specific death rates from all causes of death other than neoplasms have features that resemble those of corresponding rates for all neoplasms. The same generalization holds in connexion with specific neoplastic and non-neoplastic disorders. In both categories of disease many age-patterns suggest that the rate-governing mechanism for their occurrence is stochastic in character; a rather small number of random events, generally fewer than ten, suffice for their initiation. It is not immediately obvious how a widespread degenerative disorder, sometimes involving an astronomical number of target cells, can be initiated by only a few random events. We infer that all such disorders, together with natural cancers, are autoaggressive in nature. They are initiated by random somatic mutations in comparator stem cells of the central system of growth control. Mutant stem cells propagate forbidden clones of cells that attack target cells at one or multiple sites. (In certain disorders, the presence of an extrinsic precipitator in the host in essential to the propagation of forbidden clones). Autoaggressive attacks have consequences that range from the destruction of target cells to their transformation with invasive proliferation. Senescence can be regarded as the cumulative effect of predominantly late-onset autoaggressive disorders. The relevance of studies of twins to this unified theory is discussed.
Twin Studies of Disease Heritability Based on Medical Records: Application to Acne Vulgaris
Authors: Friedman Gary D. 
Published: July 2016

AbstractEstablishment of the Kaiser- Permanente Twin Registry permitted the study of disease heritability in twins based on review of the twins' medical records. The records of 930 pairs of twins were reviewed. Based on previous questionnaires, 342 pairs were MZ, 345 were DZ and 243 were of unknown zygosity. Because of the age distribution of these twins and the time period in which they received care, conditions of youth, such as acne vulgaris were most reliably studied Heritability of acne was assessed in three ways; all indicated a substantial genetic influence. Certain problems with twin studies using medical records became apparent: 1) Zygosity information is often lacking; 2) Differing times and durations of observation of the two twins in each pair must be accounted for; 3) Categorization by diagnosis is difficult and strict criteria for diagnosis may be impractical; 4) Patients' behavior that affects assessment of disease concordance must be considered; 5) The order in which records are reviewed may influence apparent concordance.
The Twins Foundation: Twins Take Up the Challenge
Authors: Cassill Kay 
Published: July 2016

AbstractRevelations about twins are abundant, but the information often is inaccessible. Therefore, The Twins Foundation, a multifaceted, international, nonprofit agency has been formed. Through development of a Research Library, Museum and Hall of Fame, it will (1) provide archival and research support to the growing number of disciplines involved in twin studies; (2) provide a central repository and clearing house of information about twins for the general public; (3) enlist twin achievers to act as role models for adolescent twins; and (4) collect information about the contributions twins have made to their societies in order to dispel still prevalent negative stereotypes about multiples. (Note: The term “twin” is used generically and implies all multiples).
The Secular Trend of Twinning in Australia, 1853–1982
Authors: Doherty J.D.H. , Lancaster P.A.L. 
Published: July 2016

AbstractThe incidence of twinning in Australia from 1853 to 1982 is described. The overall trend was determined by changes in the dizygotic rate and, for more than a century, it has been similar to that found in Finland and the South of Italy. It is not explained by demographic changes and there is no clear relationship with industrialisation or psychosocial factors. Monozygotic twinning has increased, most markedly in the 1970s. No adequate explanation has been given for this increase, so continuing surveillance in many different populations is necessary.