In a wide survey of twin births which was made in Sardinia, covering the years from 1902 to 1954, it was found that there was an incidence of 9.2 multiple births out of a thousand, which may be considered the lowest for any of the regions of Italy. The survey comprised not only the three provinces, but individual zones which are distinguished by historical and geographical differences.

In each of these areas a different trend appeared in what might be termed the twin phenomenon due, obviously, to the characteristic hereditary traits of the population, the degree of isolation and the endogamy which has usually been praticed over a long period.

In a commune of Campidano di Cagliari, Serramanna, research was made to ascertain what part heredity played in twin births, with positive results.

Furthermore, MZ and DZ twins were studied for the resemblance or non-resemblance in certain characteristics such as the form and colour of the hair, the skin colour, the m.c.c, the colour of the iris.

This survey of twins has shown itself to be a truly suitable method for the study of the patrimony of heredity of the Sardinians who are a Mediterranean population which are anthropologically and ethnically a distinct group on their own.

The ability to secrete ABH antigen in the saliva has been determined in 160 men and 87 mothers with 45 boys and 42 girls. Mother-child studies on the secretor-nonsecretor distribution and Gc serum types showed a good agreement between observed and expected numbers in the different classes.

The ability to smell HCN has been examined in a sample of 2619 subjects from Hyderabad, Andhra Pradesh, belonging to different Indian ethnic groups. One single antimode, between concentrations of 5% and 10%, has been found. No sex nor ethnic differences were noted. Previous claims of possible sex-linked inheritance could not be confirmed.

The fact that controls as are maintained in most biological experiments, could even be studied ebulliently in human population, by observing a MZ pair, a member of which is exposed to a certain anomaly and the other acts as control, becomes more vivid and recommended from the present studies. For, they can be directly related to human health and welfare.

Permanent changes due to typhoid incidence in physical, mental and anthropometric traits of a member of MZ twin pair may be suggestive of some “beneficial interaction of typhoid bacillus with certain intricate mechanisms like RNA and protein synthesis, as has been envisaged earlier.

Out of 446 twin births in 1946-1971, 177 (19.8%) were stillborn or perinatally dead. The main reason of twin perinatal mortality is prematurity, which is also confirmed by clinical and anatomopathologic findings. The essential role in the reduction of perinatal mortality is being attributed to ambulatory “K” Centres through early diagnosis of multiple pregnancy and pregnant women hospitalization at 30-32 weeks of pregnancy.

It is suggested that the rise in a population depends not only on the number of females per thousand males, their fecundability, and the survival of offspring (mean live births), but also on the genetic background or inbreeding status of the fetuses. Abortions and stillbirths add to the interference. A hypothetical formula has been devised , where Mb = mean birth rate, G = growth percentage of population sample from preceding Census, F = inbreeding coefficient, Sa = Stillbirths + abortions, and Sr = Sex ratio. It is intriguing that the product, being termed Fraternal Component (FC), is found to be almost equal to the DZ twinning rate of the population sample. Should that be confirmed, one could perphaps estimate the DZ twinning rate by an altogether new approach.

The proliferative characteristics of human acute leukaemia cells are reported and the relationships between the proliferative alterations and differentiation defect of these cells discussed. The proliferative activity of acute leukaemia cells was also studied in relation to cytostatic treatment.

Emphasis is laid on the fact that in all cases of acute leukaemia the characteristic blast cells of the disease do not constitute a homogenous cell population but can be divided into various sub-classes with different kinetic and proliferative characteristics. It is also pointed out that all cytostatic treatment acts on the most actively proliferating classes and only indirectly on the non-proliferating classes.

Finally, the need for more detailed study of DNA synthesis at chromosome and sub-chromosome level for the purpose of more fully understanding the response of leukaemic cells to the various chemiotherapies is underlined.

In order to evaluate the influence of birth order and fetal presentation on antenatal growth of twins we conducted a comparison of prospective measurements of five fetal biometric indices in 50 vertex-vertex and 47 vertex-breech twins. We compared (a) twin A to twin B in both groups; (b) the second and (c) the first twins of both groups. Both groups had similar maternal and neonatal characteristics. The growth curves of the twins were also very similar except for three significant (p<0.05) deviations: (a) Twin A of the vertex-vertex group, had larger femur length (FL) at 18-19 weeks, abdominal circumference (AC) and estimated fetal weight (EFW) at 29 weeks, and EFW measurements at 36 weeks, (b) Second breech twins, compared to their second vertex cohorts, had significantly smaller biparietal diameter (BPD), head circumference (HC) and FL at 18-19 weeks, BPD and HC at 29 weeks, and EFW at 37 weeks, (c) First twins of the vertex-breech group, as compared to first twins of the vertex-vertex group, had significantly smaller BPD and AC at 18-19 weeks, FL and AC at 21-22 and 29 weeks, FL at 31 weeks, and EFW at 27-28 and 36 weeks' gestation. We concluded that significantly different sonographic fetal indices may be measured at about 20 and 30 weeks' gestation, but not later. An adaptive mechanism attributed to fetal presentation is suggested to explain similar birthweights in spite of these antepartum differences.

A prospective study was undertaken to determine the effect of twin birth-weight discordancy on Apgar scores and umbilical blood acid-base parameters. Using the paired t-test, small but statistically significant differences were seen in these parameters favoring the heavier twin over its lighter sibling. These differences were also affected by birth order, with the first-born being favored.

The problem of the familial incidence of cancer has been studied on the basis of the genetical researches of the last ten years on leukemia, cancer of the breast, uterus, prostate, bladder and stomach. The conclusion has been reached, except for the cancer of the bladder, of the existence of a significant familial incidence of cancers.

Segregation and twin disease concordance analyses have assumed a theoretical underlying liability following a multivariate normal distribution. For reasons of computation, of incorporation of measured explanatory variables, and of testing of fit and assumptions, newer analytical methods are being developed. The regressive logistic model (RLM) relies on expressing the pedigree likelihood as a product of conditional probabilities, one for each individual. In addition to logistic regression modelling of measured epidemiological variables on disease prevalence, there is modelling of vertical transmission, of transmission of unmeasured genotypes and of sibship environment. This paper discusses methods for the analysis of binary traits in twins and in pedigrees. Some extensions to the RLM for pedigrees which include twins are proposed. These enable exploration of twin concordance in the context of the twins' common parenthood, the sibship similarities within the family, and the twins' similarity in age, sex, genes and environment.

This study involves the presentation of a kindred from Southwestern Louisiana showing 66 individuals who were heterozygous for a rare dominant gene for a type of Charcot-Marie-Tooth disease with hypertrophy of peripheral nerves. Two marriages between heterozygotes resulted in the occurrence of five homozygous offsprings. Clinical features of these previously undescribed homozygotes are compared to the clinical features of the classic type of heterozygote. The value of using nerve-conduction time to detect the asymptomatic heterozygote for Charcot-Marie-Tooth disease is discussed.

Cells from blood stains in absorbent and nonabsorbent materials like stainless steel, unpolished wood, cloth, glass, and paper, can be correctly sexed using fluorescent stains even after 90 days, during which the stains had been exposed to light, unfixed.

In 1969 children of a multiple birth in the GDR made up 1.9% of livebirths and 15.3% of early neonatal deaths. The early neonatal mortality rate of children from a multiple birth was 95.7‰, that of all live-births 12.4‰. The cause was the low birth weight of children from a multiple birth (56.2% vs. 5.8% of all livebirths). Their low birth weight is the result of a hypotrophic development caused by malnutrition. The loss of children from a multiple birth (stillbirths, early neonatal and postneonatal deaths) was 143‰. International experience has shown that such heavy losses can be largely prevented by bed rest of the woman with a multiple pregnancy. We therefore strongly recommend early diagnosis and early in-patient care of women with multiple pregnancy.

Since the MNS blood group system does not exhaust the total degrees of freedom under the Wright's equilibrium law, it was felt that the peculiar problems facing the detection of F (the fixation coefficient of Wright's model) from ABO blood group data may not be totally relevant to the MNS system. To verify this, a short discussion on the detection of F from MNS blood group data is given here.

This study was performed to examine the main characteristics of the French Romulus twin population: zygosity, chorionicity, sex, term and birthweight. A sample of 104 pairs of twins was distinguished by zygosity, chorionicity and sex, and divided into concordant and discordant birthweight groups. Fifty-three % (n = 55) of the fetus pairs studied were born at “ideal term” (35-38 weeks), and 25% (n = 26) were delivered at “preterm” (28-34 weeks). The very preterm (< 28 weeks), and “postterm” (> 38 weeks) represented altogether 22% (n = 23) of the sample. Of the 104 twin pairs, 68% (n = 71) differ by less than 15% in birthweight, and 32% (n = 33) have a birthweight difference higher than 15%. In dizygotic (DZ) pairs females had more tendency to be in the discordant group (p = 0.01) while in monochorionic-monozygotic (MC-MZ) pairs males were more discordant (p = 0.07). We found a significant interaction between sex and zygosity type (p = 0.02). Males had a birthweight difference significantly weaker than that of females in dichorionic-monozygotic (DC-MZ) and DZ twins whereas it was higher than that of females in MC-MZ twins. There were no MZ twin pairs with DC placentation over than 15% birthweight difference. Log linear analysis demonstrated a three-way interaction (p < 0.05) between term type, zygosity type and hypotrophy. Our data indicate that in the group of twins born between 35 and 38 weeks' gestation the crucial question still remains unsettled on how term and birhweight are related to zygotism and/or chorionicity.

Natulan (Procarbazine) is a methylhydrazine derivative which in animal experiments inhibits a series of transplantable tumours. The Walker carcinoma is markedly affected. Even well established Walker tumours disappear completely under Natulan treatment. Tumour tissue is replaced by fibrous tissue. Natulan does not act selectively on neoplastic tissue, it also depresses the growth of other rapidly proliferating tissues such as the bone marrow.

As regards the mechanism of action the following data are known: Natulan lowers the mitotic index by prolonging the interphase and hindering the cell from entering into mitosis. In Ehrlich ascites tumour cells chromatid breaks were observed. Natulan depolymerizes deoxyribonucleic acid (DNA) in vitro. In vivo the synthesis of DNA is inhibited. Furthermore alkylation of purine bases has been demonstrated. All these mechanisms may be responsible for the cytotoxic effect of methylhydrazine derivatives. Natulan does not possess cross-resistance towards other cytotoxic agents. This phenomenon is a further proof of its particular mechanism of action.