bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Changing Incidence of Twinning in Scotland in 1939-1968
Authors: MacGillivray Ian 
Published: July 2016

The rate of twinning, both MZ and DZ, as determined by the Weinberg formula, remained fairly static in Scotland up to 1958, when it fell (Fig. 1), due to a fall in the DZ twinning rate. These figures are based on the returns from the Registrar General for Scotland.As age has a marked influence on the incidence of twinning, it was thought that the difference might be due to a reduced number of older women having babies. However, this does not seem to be the whole answer (Fig. 2). The most marked change would be expected in the women over 35, but this did not occur. It was not possible to look at other factors such as parity, social class and height in the figures for Scotland. The details of all births in the City of Aberdeen are known because of the very high hospital delivery rate, and more detailed studies have been made on the twinning rates for Aberdeen.These figures, again, showed that from 1959 onwards there was a fall in the twinning rate in Aberdeen and this was due to the fall in the number of DZ twins. The fall in incidence occurred both in Primigravidae and in multigravidae (Tab. I), and more in older than in younger Primigravidae (Tab. II), but there was little difference by age in the fall in multigravidae (Tab. III).Another factor which is related to the incidence of twinning is the height of the mother. This, in turn, reflects the social class, as tall women are more commonly from the upper, and small women from the lower social classes. The rate of twinning in Aberdeen was highest in the tall women before 1954 (Tab. IV). The rates in all women fell from 1954 onwards, but most dramatically in the tall women. The rates from 1959 onwards show very little difference according to height.
Leukocytic Infiltration of the Umbilical Cord in Twins
Authors: Thiery M. , le Sian A. Yo , Derom R. , Boelaert R. 
Published: July 2016

Leukocytic infiltration of the umbilical cord, particularly of the umbilical vein, is common both after normal and abnormal delivery (Tab. I).The significance and the cause(s) of this phenomenon, however, are still highly controversed subjects (Tab. II). According to some authors (Benirschke, i960; Benirschke and Clifford 1959; Blanc 1961; and Kelsall et al, 1967), cord infiltration may be an indication of intrauterine fetal infection. As a consequence, the terms vasculitis, umbilical phlebitis and funiculitis have been introduced. Other authors (Barter, 1962, and Dominguez et al, 1960), mostly impressed by the discrepancy between the incidence of clinically evident neonatal infection and funiculitis, as well as by the significant association of cord infiltration with prolonged labor and clinical signs of fetal distress, have come to the conclusion that leukocytic infiltration of the umbilical cord must predominantly be the effect of fetal hypoxia. Dominguez et al (i960) go even further and postulate “that the examination of the umbilical cord for leukocytic infiltration affords a means for a long term study of children to determine the effect of intrauterine hypoxia on their ultimate growth and development”.One way to check the validity of the latter hypothesis, is to investigate the umbilical cords of twins. Since our group has proven that, compared to the first-born twin, the second-born infant is as a rule significantly more hypoxic at birth (Derom and Thiery, 1969), one may expect that intragroup comparison of the incidence of leukocytic infiltration of twin cords should at least permit to disprove the validity of Dominguez assumptions.
Twin Models
Authors: Gedda L. , Brenci G. , Lun M. T. 
Published: July 2016

The theoretical relationship between the distribution of a given trait in a population of twin pairs and several genetic parameters has been examined. In particular, a series of mathematical models has been worked out, that, when applied to a twin population, nonselected for the occurrence of a given trait and nondiagnosed as to zygosity, leads to an estimate of:1) The MZ: DZ ratio in the population;2) The frequency of the genotype responsible for a given trait;3) The probability of manifestation of the trait;4) The value of epistatic factors.A further mathematical model affords the estimate of linkage in the hypothesis of simultaneous recording of more than one trait.
Distances Généralisées des Dermatoglyphes de Jumeaux
Authors: Vrydagh-Laoureux Stana 
Published: July 2016

Soixante-douze paires de jumeaux de même sexe, âgés de 6 à 22 ans, ont été examinées à Bruxelles par l'équipe du Prof. Twiesselmann. Ils ont été séparés en deux groupes, 35 paires de concordants et 37 paires de discordants pour au moins un des neuf sérums des groupes ABO, MN et Rh. Aucun élément subjectif n'est donc intervenu dans cette ségrégation basée sur des facteurs dont le mode de transmission est connu. Nous n'avons fait aucun essai de diagnostic de zygotie basé sur la plus ou moins grande similitude de caractères morphologiques, de façon à rester dans un domaine absolument objectif. Le groupe des discordants est évidemment composé uniquement de jumeaux DZ. Celui des concordants comprend tous les MZ plus vraisemblablement quelques paires de DZ.Pour l'étude des dermatoglyphes, nous avons retenu trois caractères: le nombre total de triradius digitaux (pattern intensity index), l'indice des lignes principales (main line index) et le nombre de crêtes entre les triradius interdigitaux a et b (a-b ridge-count).Nous avons d'abord étudié les corrélations entre jumeaux d'une même paire (Fig. 1). Dans le groupe des discordants sérologiques, les intervalles de confiance des coefficients de corrélation englobent la valeur théorique de 0.5. Chez les concordants, ils approchent de l'unité et les coefficients de corrélation vont de 0.83 à 0.85. Aucun de ces intervalles de confiance ne se chevauche, malgré leur étalement dû au petit nombre de sujets.
Il Disadattamento Sociale Rilievi su gemelli MZ e DZ
Authors: Gaffuri G. 
Published: July 2016

Il problema del disadattamento sociale, nelle sue diverse forme e gravità, è stato considerato attraverso l'osservazione di 60 coppie di gemelli: 30 MZ e 30 DZ, ♂♂ e ♀♀, dai 15 ai 55 anni, vissuti rispettivamente in ambienti identici o differenti per tutta la vita o solo nell'età infantile-giovanile, oppure nell'età adulta. Sono state escluse, dall'osservazione le coppie di soggetti affetti da sofferenze organiche, neurologiche e psichiche, tali da giustificare anomalie del comportamento e quindi disadattamento sociale. I casi, trovati nel corso di 25 anni, sono stati studiati attraverso inchieste socio-familiari ed esami obiettivi clinici e di laboratorio, generici e specialistici, particolarmente quelli propri della clinica neuro-psichiatrica.Le inchieste sono state condotte per tutte le età ed ogni ambiente, per raccogliere informazioni attendibili ed obiettive che investissero l'intera vita dei soggetti, contribuendo alla comprensione psicodinamica delle anomalie comportamentali ed in particolare del disadattamento sociale. Gli esami obiettivi e collaterali psichiatrici (colloqui psicodiagnostici e test psicoproiettivi), più volte ripetuti a distanza anche di anni, hanno permesso di precisare i singoli quadri clinici ed hanno fornito gli elementi per la loro interpretazione.In tutti i gemelli MZ vissuti in ambienti identici (10 coppie), sono riscontrabili rilevanti concordanze. In quelli vissuti in ambienti sostanzialmente differenti (4 coppie), non è stato rilevato alcun caso di perfetta concordanza: concordanze parziali in 2 coppie e marcate discordanze nelle altre 2.
Congenital Malformations in MZ Twins
Authors: Derom R. , Cameron A. H. , Edwards J. H. , Thiery M. , Boelaert R. 
Published: July 2016

Congenital malformations have been investigated in a consecutive series of 445 MZ twin pairs coming from two twin surveys numbering 1424 pairs.Concordant malformations were found in 6 pairs; discordant malformations, in 20 pairs. The significance of these findings is briefly discussed.The methodology of the prospective twin studies is described. The diagnosis of zygosity is based on sex, structure of placental membranes, and enzyme systems of the blood and placenta.
Le Malformazioni nell'Uomo — Studio gemellare
Authors: Del Porto G. , Del Porto-Mercuri A. 
Published: July 2016

Molto spesso la genetica si è interessata delle malformazioni allo scopo di evidenziare il « quantum » di eredità che interviene nel determinismo morboso, specialmente quando la patologia denunciata è causa di grave alterazione del fenotipo.Lo studio attuale vuole invece valutare l'importanza dell'eredità in un settore meno impegnativo della patologia malformativa, ma a nostro avviso assai diffuso, e cioè il peso dell'eredità sul determinismo di: (1) palato ogivale; (2) valgismo delle ginocchia; (3) malformazioni genitali; (4) piedi piatti; (5) malformazioni della colonna vertebrale; (6) malformazioni dentarie; (7) malformazioni delle dita; (8) malformazioni craniche.Ben note sono le difficoltà che si incontrano in campo umano per l'impossibilità di procedere ad una sperimentazione diretta, ed è quindi il metodo gemellare ad apportare un contributo essenziale nella valutazione dell'eredità e dell'interazione di fattori paragenetici ed ambientali sull'evento patologico, mediante lo studio delle coppie gemellari MZ e DZ.Nel nostro caso abbiamo raccoito 240 coppie gemellari delle quali 120 MZ e 120 DZ, che sono state distribuite in otto classi corrispondenti alle otto patologie descritte a seconda della rispettiva presenza in entrambi o in un solo gemello.
Twinning and Blood Groups — I. ABO frequencies in twins and controls: immunological considerations
Authors: Bolognesi M. , Milani-Comparetti M. 
Published: July 2016

Several studies have appeared in the literature to support the hypothesis of a differential incidence of twin births according to the antigenic structure of maternal erythrocytes (Gedda, 1961).Osborne and DeGeorge (1957) wrote that twin births exhibit a higher incidence when mothers belong to group O, as compared to other groups within the ABO system; a similarly increased incidence of twin births was indicated for rh-negative mothers within the Rh-Hr system.The availability of a large number of immunohematological data concerning twin pairs and nontwin individuals examined in our Institute have encouraged us to verify whether this material could reveal some a posteriori effect of the selective tendencies that have been related to the parental level.Limiting our study in this phase to the ABO system, we have collected data on 1190 twin individuals and 1454 nontwin individuals, for all of whom the ABO blood group had been recorded.The first step in our analysis was the perequation of the nontwin distribution to the twin distribution, obtaining the figures reported in the column “controls” in Tab. I.
Allergy and Disease in Twins — An anamnestic study
Authors: Milani-Comparetti M. 
Published: July 2016

The immunological nature of allergic diseases is a recognized fact, but their pathogenesis is still largely unknown, representing one of the less understood areas of immune pathology.Twin studies in allergic diseases have been carried out before (Gedda and Teodori, 1962), contributing to prove the great importance of heredity in the occurrence of allergic disease.Yet, the nature and mode of inheritance of allergic hereditary factors is still unknown, thus representing further question marks in the mystery of allergic pathogenesis.The present study has been extended to include allergic diseases within the wider scope of total pathological experience, through a comparison between a sample of twin pairs with a history of allergic disease and a control sample of nonallergic twins.All our data have been derived from the records of the Twin Register of the Mendel Institute. These records have been coded and transferred onto IBM punched cards with the support of the Italian National Research Council (Gedda and Milani-Comparetti, 1966). A population of 500 twin pairs was selected for having been included in the Twin Register before 1955, so as to have a minimum age of 15 years. The case histories of all these pairs had been coded and punched independently, according to a coding system developed in our Institute, which listed the following items: (1) oculorhinitis; (2) asthma; (3) urticaria; (4) allergic eczema; (5) unspecified allergic disease.As many as 76 of our 500 pairs were found to have a positive history for at least one of these classes of disease, representing an incidence of 15.02% in our material.
Coronary Occlusion in Twins
Authors: Harvald B. , Hauge M. 
Published: July 2016

It seems to be generally accepted that genetic factors take a place among the causes of coronary heart disease. Careful and extensive family studies, among others by workers in Carter's group, have shown that the risk to close relatives of patients with coronary heart disease is significantly increased. This may, however, be an effect of the common social background in families. Systematic twin investigations have been needed, which could distinguish between the effects of common environment and common genes, and allow an estimate of the relative importance of genetic and environmental factors.The present study is an approach to this problem by using twins with coronary heart disease in the Danish Twin Register (Hauge et al, 1968). This was founded in 1954 and has been developed ever since. It now contains total medical information on about 10 000 unselected pairs of twins born in Denmark in the period 1870-1910, where both partners have survived the age of five. On January 1, 1968, coronary occlusion had been registered in a total of 352 twins.
Twin Studies in Congenital Heart Diseases
Authors: Jörgensen G. 
Published: July 2016

Uchida and Rowe (1957), Lamy et al (1957), as well as Campbell (1961), were of the opinion that genetic factors do not play an important role in the genesis of congenital heart deformities. These authors could not find any concordantly affected pair among a total of 32 MZ twin pairs. Impressive family case reports and systematic investigations (Fuhrmann, 1970; Jörgensen, 1970) do not support this assumption. The results of twin investigations by Nora et al (1967) also contradict previous results. Among a total of 37 twin pairs these authors found 6/13 MZ and 1/24 DZ concordantly affected pairs.Our own investigations began in autumn, 1966 and were recently completed. With the help of the registrar of birth offices and the cardiological team of the University of Göttingen (Prof. Dr. A. J. Beuren, Prof. Dr. H.-E. Hoffmeister, Prof. Dr. J. Koncz, Prof. Dr. J. Stoermer), we were able to find 50 index patients, each being a member of a twin pair, among 2427 propositi with different congenital heart defects.Our own results are shown in Tab. I: 4/21 MZ (19.0 ± 8.6%) and 1/24 DZ (4.2 ± 4.1%) are concordantly affected. In five cases, the zygosity of the twins, as well as the diagnosis of respective cotwins, (stillborn or perinatal-dead) is unknown.
Applicazione del Metodo Gemellare nello Studio dell'Enuresi Primitiva
Authors: Gedda L. , Alfieri A. , Brenci G. , Reggiani L. , Lun M.T. 
Published: July 2016

L'enuresi primitiva (essenziale notturna) può essere definita come una minzione involontaria che avviene di notte durante il sonno, mentre nel corso della giornata la minzione è normalmente controllata, ed ha perciò caratteri peculiari.Il notare, a volte, nei bambini affetti da enuresi primitiva la concomitanza di piccoli disturbi psichici o emozionali, di piccolo male, di stati di ipervagotonia o spasmofilia, conferma la natura funzionale complessa dell'affezione, sulla quale influiscono in prevalenza turbe della vita psichica o degli interessi affettivi del bambino. Alcuni dei fattori psichici implicati nell'enuresi (mancinismo, infantilismo nei giochi o discorsi, terrori notturni, fobie) possono anche essere considerati come indice di una incompleta maturazione psichica.Non vogliamo qui discutere sull'etiopatogenesi della malattia, che è tuttora piuttosto oscura. La maggioranza degli autori considera l'enuresi primitiva come un disturbo funzionale complesso, non legato ad alterazioni dell'innervazione o della maturazione delle strutture nervose e muscolari preposte alla funzione vescicale, ma piuttosto riportabile ad alterazioni (o ritardo) del meccanismo volontario della minzione.Si parla di enuresi primitiva quando il controllo anche notturno della minzione non è stato raggiunto entro i primi tre anni di vita. Secondo Harrison (1967), a 5 anni l'enuresi è presente nel 15% dei maschi e nel 10% delle femmine, a 9 anni nel 5%. Il disturbo cessa spontaneamente alla pubertà in quasi tutti i casi.
Concordant Glaucoma in MZ Twins
Authors: Gedda L. , Scullica L. , Accardi A. 
Published: July 2016

The Authors report a 54-year-old male MZ twin pair with two single-born relatives suffering from glaucoma.The twins are concordant as to glaucoma, but onset of the disease in the first-born occurred 20 years later than in the second-born. This high chronological difference is ascribed to the hardships the latter twin had suffered for three years in Africa.The meaning of anticipation is discussed in the light of modern views on the time dimensions of the unit of inheritance (chronon).
A Comparison of Heritability Estimates of US Negro and White High School Students
Authors: Vandenberg S. G. 
Published: July 2016

As you all know, there is a growing concern with the Negro problem in America. I will look at one small aspect of that problem today: the possible hereditary difference in ability between Negro and White.Fig. 1 is just one of many examples that could be chosen. It shows the extent of such differences in ability for different years, for male and female separately, between Negro and White students admitted to the University of Georgia, as reported by Hills (cf. Stanley and Porter, 1967). Ability was measured by the verbal score on the Scholastic Aptitude Test — a test widely used by college admission officers in the USA for selection of students.Fig. 2 shows a comparison of the fertility of Negroes and Whites, indicating that less able Negroes have the highest fertility, while more able ones have lower fertility (Bogue, 1969).Should the combined effect of these two factors (i.e., lower IQ,'s and greater fertility of low IQ, Negroes) lead us to worry about a gradual decline of the national level of intelligence in the USA? I believe not, and I will present some evidence which supports the thesis that the observed lower intelligence in US Negroes is due to an interaction between innate potential and unfavorable environmental conditions. If, as I believe, social conditions for the Negro are improving and if their greater fertility will level off as social conditions improve, we will not need to be concerned about a national decline in ability.
A Comparison of Twin and Sibling Studies for a Developmental Theory of Schizophrenia
Authors: Pollack Max , Woerner Margaret G. , Klein Donald F. 
Published: July 2016

Studies have clearly established that the concordance rate for schizophrenia is much higher in MZ than DZ twins. Beyond this, it is difficult to generalize the findings to singletons. Analyzing the reports of MZ twins discordant for schizophrenia, Stabenau and Pollin (1967) view the differences between the index case and his nonschizophrenic cotwin, as stemming from an early biological defect or immaturity, which, in interaction with parental handling and other environmental response, may lead to socio-psychological incompetency and, in turn, to gross schizophrenic symptomatology.In a previous study (Pollack et al, 1966), comparing schizophrenic patients and their nonschizophrenic sibs, we found that patients showed significant psychological (social and personality) deviations from the preschool age through adolescence. We did not obtain significant differences on the biological and very early developmental variables that clearly distinguished the discordant twins. These include birth weight, paranatal complications or motor development, such as age of walking. In contrast, Lane and Albee (1966) found schizophrenic index cases to be lighter at birth than their sibs, confirming the finding for twins. The clinical significance of this difference is debatable, since the index cases did not differ from national norms.
Family Studies of MZ Twins Discordant for Schizophrenia: Neurological Findings
Authors: Mosher L. R. , Pollin W. , Stabenau J. R. 
Published: July 2016

Over the past six years the Section on Twin and Sibling Studies, NIMH, has conducted intensive studies of 16 families with MZ twins discordant for schizophrenia. In addition, 3 families in which both twins were schizophrenic and 4 with no known psychiatric illness have been similarly investigated.Each family is admitted to the Clinical Center, NIH, for two weeks of multi-disciplinary investigation. In the hope of shedding light on the question of neurologic findings in schizophrenic patients and their role in this disorder, detailed neurological examinations are performed on the twins by two neurologists. Patients with gross neurologic disturbance are screened out by our selection criteria. The examiners are therefore explicitly seeking minor deviations in neurologic status, rather than patterns of symptoms and signs leading to a specific neurologic diagnosis. Given this context, the neurologists recorded substantial numbers of signs. Yet, in none of the twins was there sufficient evidence to warrant a neurologic diagnosis.The pairs of neurologic reports were subjected to a variety of procedures, in an attempt to quantify the results. For example, 11 of the first 13 index schizophrenic twins, as compared with 1 of 13 cotwin controls, were rated as having “probable” or “definite” neurologic abnormality, based upon the senior author's analysis of the number and type of signs recorded and the degree of agreement between the examiners. Significant group differences on number of signs reported were found between schizophrenics and nonschizophrenics, schizophrenic indexes and their cotwin controls, and schizophrenics and normals. In contrast, there were no significant group differences in the number of signs found between the nonschizophrenic cotwin controls and the normal twins.
A Twin Study of Suicide
Authors: Juel-Nielsen N. , Videbech Th. 
Published: July 2016

Suicide is a complex problem and a phenomenon of mankind which is obviously influenced by a multitude of ethnological, socio-cultural, psychological and various other factors.That a man takes his own life does not necessarily mean that he was mentally abnormal. On the other hand, it is a well established fact that the frequency of mental illness — affective disorders in particular — is high among suicides, and that one in six patients suffering from manic-depressive psychosis will commit suicide (Sainsbury, 1968). A family history of suicide is not quite uncommon, and beforehand one cannot exclude the possibility that somehow genetic factors may play a part in suicide; but evidence in favour of such an assumption seems to be scanty.A survey of the literature reveals that there have been very few twin studies of suicide, and so far concordance in MZ twins seems to have been reported in three cases only.The first case was observed, already in 1812, by a Dr. Stephens Williams from Massachusetts. He described twin brothers, presumably MZ, who both were captains and had distinguished themselves in the War of Independence. One of the twins settled down in the beautiful state of Vermont, whereas the other remained in Springfield. For several years, they continued to live apart, until, within short interval, they both committed suicide by cutting their throat. Williams points out that the mother and two siblings of the twins had presented symptoms of mental illness, and that, prior to their death, both had been in a state of melancholy, probably an endogenous depression.