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Biomedical subjects

P Magnus

Publications and source records attributed to P Magnus.

At least 163 records · Page 9Linked to original sources
PubMed1989

Declining mortality from ischemic heart disease and cerebrovascular disease in Australia.

The authors examined the patterns of mortality from ischemic heart disease and cerebrovascular disease in Australia for men and women aged 30-84 years during the period 1950-1986 to assess the relative contributions of period and cohort effects on changes in the mortality rates. Death rates for ischemic heart disease increased from 1950 to the late 1960s and then declined. Although the relative magnitude of the decline was greater among younger age groups, decreasing mortality rates were experienced in all age groups, including the oldest. The period effect was dominant so that each successive cohort experienced lower age-specific mortality rates after the late 1960s. Death rates for cerebrovascular disease for both sexes and all age groups have declined since the early 1950s, although the rate of change was less in 1961-1971 and greater before and after this period. No cohort effect was demonstrated for either disease. Changes in diet, decreasing prevalence of cigarette smoking, and increasing treatment of hypertension throughout the period and improved coronary care from the late 1960s onward are all consistent with the mortality trends.

Adult↗
PubMed1989

Familial clustering in the polycystic ovarian syndrome.

To assess the degree of familial clustering and the mode of inheritance of the polycystic ovarian syndrome (PCO), the prevalence of PCO-related symptoms among first- and second-degree relatives of 132 PCO patients and 71 controls was studied using questionnaire data. 19.7% of male first-degree relatives of PCO patients were reported to have early baldness or excessive hairiness, as opposed to 6.5% of relatives of controls. For female first-degree relatives, the percentages for PCO-related symptoms were 31.4 and 3.2, respectively, in the two groups. In a subgroup of 52 families of PCO patients where one of the parents was reported to have symptoms, 35% of brothers and 58% of sisters had symptoms. Although autosomal dominant inheritance could be excluded as an explanation for PCO in the whole data set, the findings were consistent with this mode of inheritance for a sizeable fraction of families. X-linked dominant inheritance of PCO could be discarded.

Adult↗
PubMed1987

Left-handedness in twin families: support of an environmental hypothesis.

Information on handedness, assessed as writing-hand, was collected from 197 MZ twin pairs and 203 DZ twin pairs and from their parents, spouses, and children. Associations for pairs of relatives were studied by 2 X 2 tables, computing chi squared-values and tetrachoric correlations. Correlations of about .3 were obtained for mother-offspring and sibling pairs, while for cousins the correlation was .25 (in a small sample). No other significant associations were found, not even for twins. These results suggest only a small, if any, genetic effect, and only a small environmental between family effect, most of which seems to be a maternal effect. The lack of cotwin correlations and correlations for one of the twins with her/his ordinary brothers/sisters suggest the existence of an effect specific to twins, since the correlation for pairs of ordinary siblings is significant. Conclusions drawn from twin studies alone may be biased. The frequency of left-hand writers has increased from 1% to 10% in the different age groups born during the last century in Norway. This age effect is present mainly in hand writing and not so much in handedness generally, suggesting a decrease in cultural repression against left-hand writing.

Adult↗
PubMed1986

Education level and coronary risk factors in Australians.

There is an inverse association between social class ranking and mortality from coronary heart disease in Australia and in some other countries. To explain whether this association is related to differences in risk factors, the relationship between coronary risk factors and the highest level of education completed was explored for a reasonably representative cross-section of the adult Australian population. After adjustment for the effects of age, relative weight and alcohol intake, blood pressure was found to vary inversely with education level in both sexes. In men only plasma cholesterol, triglycerides and high density lipoprotein cholesterol levels showed no significant variation with education level. In women, plasma triglycerides and high density lipoprotein cholesterol levels varied inversely with education level after adjustment. There was less cigarette smoking among more highly educated men but no clear smoking trends among women. The findings broadly confirm the results of similar analyses which used occupation as the measure of social class and have implications for future community education programmes in that present strategies may be inappropriate for less highly-educated members of society.

Alcohol Drinking↗
PubMed1986

Increased levels of apo-transcobalamins I and II in amniotic fluid from pregnant women with previous neural tube defect offspring.

In an attempt to identify biochemical components of the genetic predisposition to neural tube defects (NTDs), levels of folate, cobalamin, apo-transcobalamins I and II and alpha-fetoprotein were studied in midtrimester amniotic fluid from 24 pregnant women who had previously had a child with NTD. The control group consisted of 76 mothers, subjected to amniocentesis for reasons other than risk of NTD in offspring. Only pregnancies with normal outcome were included. No differences were found between groups for levels of folate, cobalamin or alpha-fetoprotein. Folate intake or metabolism did not appear to differ between groups. In contrast, the level of apo-transcobalamin I was doubled and the level of apo-transcobalamin II tripled in amniotic fluid from women who had had a child with NTD compared with the control group. Since the variation in apo-transcobalamin II in adults is to a high degree genetically determined, the present results may suggest that the genetic predisposition to NTD is associated with variation in this protein. Further studies are needed to substantiate or reject this possibility.

Adult↗
PubMed1985

The association of parity and birth weight: testing the sensitization hypothesis.

The increase in birth weight with parity was studied in sibships of 2, 3, and 4 children using large samples from the Norwegian Birth Registry. Families with full sibs were compared to families with maternal half-sibs. The sensitization hypothesis of Warburton and Naylor predicts no increase in birth weight with parity when the mother changes mate. The hypothesis was not supported by the data, since similar increases in birth weight with parity were found in both types of families. A small effect of the sex of the first child on the birth weight of the later born children was observed.

Adult↗
PubMed1985

No significant difference in birth weight for offspring of birth weight discordant monozygotic female twins.

Birth weights of offspring of 105 female, monozygotic twin pairs discordant in birth weight were studied. No significant differences were found when offspring of the larger twin were compared with offspring of the smaller twin. The results do not support the hypothesis that in utero effects on females associated with low birth weight will influence their subsequent chance of having low birth weight offspring.

Birth Order↗
PubMed1985

Association of parental consanguinity with decreased birth weight and increased rate of early death and congenital malformations.

Data on parental consanguinity have been recorded for all births in Norway since 1967. Pregnancy outcome for offspring of 848 women mated to their first cousins were compared with offspring of 1,696 control women. The stillbirth rate was 23.6 per thousand for cases and 13.4 for controls. The neonatal death rate was 34.9 per thousand for cases and 14.3 for controls. The recurrence risk for sibs for early death was 9.4% for cases and 4.2% for controls. The mean offspring birth weight was significantly lower (3377 g vs. 3491 g), and the variance in birth weight was slightly larger for cases than controls. The percentage of children with malformations detected shortly after birth was 4.6% for cases and 2.2% for controls. The differences may be attributed to the increased homozygosity in offspring of first cousins. The results have relevance for genetic counselling to consanguineous couples, as well as for the understanding of the etiology of adverse pregnancy outcome and for elucidating the causes of variation in birth weight.

Birth Weight↗
PubMed1985

The heritability of smoking behaviour in pregnancy, and the birth weights of offspring of smoking-discordant twins.

Questionnaire information on smoking habits in pregnancy was collated in 341 monozygotic (MZ) and 321 dizygotic (DZ) female twin pair cases from a population-based Norwegian Twin Panel. In a multifactorial model, the intra-pair correlation in smoking was 0.797 (+/- 0.042) in monozygotic (MZ) and 0.443 (+/- 0.075) in dizygotic (DZ) twin pairs, indicating a substantial genetic influence on liability to smoke in pregnancy. The questionnaire information was linked with birth records in the Medical Birth Registry of Norway, and birth weights of offspring of 62 MZ and 100 DZ smoking-discordant twin pairs were studied. Offspring of smoking MZ twins weighed 127 g less than birth order matched offspring of the non-smoking co-twins. This finding is additional evidence that smoking is a direct cause of reduced birth weight in offspring.

Birth Weight↗