A method of estimating the total tumour burden in patients with Hodgkin's disease was devised, combining the number of involved regions with the tumour size in each region. Further, a method of estimating the total tumour cell burden was devised, combining the estimate of the total macroscopic tumour burden with an estimate of the concentration of tumour cells in the tumour tissue. The prognostic significance of the total tumour burden was examined in multivariate studies of 300 patients in pathological stages I and II treated in the Danish National Hodgkin Study and 506 patients in all stages treated at the Finsen Institute, Copenhagen, Denmark, during a 15-year period. The total tumour burden turned out to be the most important prognostic factor in Hodgkin's disease. Most of the hitherto known prognostic factors were shown to be correlated with the total tumour burden and to lack independent prognostic significance.
Commingling and segregation of age-sex-adjusted systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MBP) were examined in 1,560 individuals from 374 French-Canadian nuclear families. After correction for skewness, evidence in favor of two commingled distributions was found for SBP in the combined data (parents and offspring) and in parents, but not in offspring. Segregation analysis (using the computer program POINTER) suggested that a multifactorial contribution to all three phenotypes was greater in offspring than in parents, which could be the result of either polygenic or shared environmental components relevant to sibships, or both. Statistical evidence was found for a major effect on SBP. However, Mendelian transmission of the major effect was rejected, and no transmission of the major effect (equal tau's) was not. This is just the opposite to what would be expected if the major effect was due to a major gene, and it would ordinarily be considered as sufficient evidence to refute a major gene effect on SBP. However, the commingling in parents but not in offspring (who are all below 26 years of age), and the finding of equal transmission probabilities (nearly equal to 1), are compatible with an alternative interpretation. It is possible that there is a real major gene effect on SBP but that the genotype for elevated SBP has not yet expressed itself in the offspring as they have not yet gone through the risk period. Accordingly, this possibility needs to be evaluated further in additional studies involving older offspring.
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To determine whether high maternal parity has any effect on pregnancy outcome independent of other maternal characteristics.
Retrospective observational study using the database of a referral obstetric unit in a 280-bed regional hospital in far north Queensland.
All 15 908 women who had singleton births between 1992 and 2001, comprising 653 women with grand multiparity (>or= 5 previous births at gestation >or= 20 weeks) and 15 255 women with lower parity.
Spontaneous vaginal birth, postpartum haemorrhage (estimated blood loss > 500 mL), placental retention requiring manual removal, blood transfusion associated with the birth, and perinatal death.
Women with grand multiparity were significantly older than those with lower parity, more likely to be Indigenous, not to have had antenatal care, to have smoked during pregnancy and to have had one or more previous caesarean sections. On univariate analysis, women with grand multiparity were more likely to have a postpartum haemorrhage (9.2% v 5.3%) and blood transfusion (2.8% v 1.5%). However, multivariate logistic regression analysis of women who began labour (ie, did not have an elective caesarean section) showed that grand multiparity was not significantly associated with postpartum haemorrhage or blood transfusion when other maternal characteristics were included in the model (regression coefficients [95% CI], 1.36 [0.99-1.87] and 1.09 [0.59-2.02], respectively). However, they remained more likely to have a spontaneous vaginal birth (regression coefficient [95% CI], 2.10 [1.56-2.74]).
Women with grand multiparity do not have an increased likelihood of poor pregnancy outcomes. Birth-suite protocols which dictate extra interventions as routine during labour in these women should be revised.
Comment In: Med J Aust. 2004 Feb 16;180(4):196-7; author reply 19714960145
Hypertension and its consequences on cognition was analyzed using data from the study "Men born in 1914" in Malmö, Sweden, a prospective cohort study of cardiovascular disease. The baseline examinations took place in 1982/83 where 500 men participated in extensive medical and social examinations. A neuropsychological investigation was completed including five standardized cognitive tests. The specific purpose of the study was to investigate whether hypertension was associated with cognitive performance. By the use of multiple regression analyses, normal blood pressure and three stages of hypertension were analyzed in relation to test performance. Hypertension Stage 3 was associated with lower performance on tests measuring psychomotor speed and visuospatial memory, whereas hypertension Stage 1 was associated with higher performance on tests measuring verbal ability and constructional ability. The associations were unconfounded by clinical manifestations of atherosclerosis, history of stroke, depressive mood, and antihypertensive drug treatment.
Dairy cow mortality has been steadily increasing during the last 2 decades in Denmark. This study aims to verify whether genetic mechanisms might be contributing to this increase. To do so, the records of 880,480 Holstein, 142,306 Jersey, and 85,206 Red Danish dairy cows calving from 1990 to 2006 were retrieved from the Danish Cattle register. Two causes of culling of cows were considered: death and slaughtering. Bivariate competing risk genetic models with a sire model structure were used to describe the death and the slaughtering rates simultaneously. The models included 2 random components: a sire random component with pedigree representing the sire genetic effects and a herd-year-season component. Moreover, the level of heterozygosity and the sire breed proportions were included in the models as covariates to account for potential nonadditive genetic effects due to the massive introduction of genetic material from other populations. The correlations between the sire components for death rate and slaughter rate were negative and small for the 3 populations, suggesting the existence of specific genetic mechanisms for each culling reason and common concurrent genetic mechanisms. In the Holstein population, the effects of the changes in the level of heterozygosity, breed composition, and the increasing genetic trend acted in the same direction, increasing the death rate in recent years. In the Jersey population, the effects of the level of heterozygosity and the breed proportion were small, and only the increasing genetic trend can be pointed as a genetic cause to the observed increase in the mortality rate. In the Red Danish population, neither the time-development pattern of the genetic trend nor the changes in the level of heterozygosity and breed composition could be causing the observed increase in the mortality; thus, nongenetic factors must be causing this negative development.
Women are often advised that lactation accelerates loss of the excess weight gained during pregnancy, but the evidence underlying this advice is sparse and conflicting. To help fill this gap, we assessed differences in the rate of postpartum weight loss in the first 9 months postpartum according to method of infant feeding.
Two hundred thirty-six women attending two public health clinics in Montreal were weighed in one to four routine infant immunization visits up to the 9th postpartum month. After each weighing, we administered a telephone questionnaire assessing the method of infant feeding (predominantly breast-feeding, mixed-feeding, or predominantly bottle-feeding) and potential confounders. Data were analyzed using unbalanced multivariate repeated measures linear regression.
Infant feeding was not associated with statistically significant differences in the rate of weight loss. Gestational weight gain, postpartum smoking, and maternal birthplace were important predictors of postpartum weight change.
Although our results cannot exclude an effect of more exclusive or more prolonged breast-feeding, breast-feeding as commonly practiced does not appear to influence the rate of postpartum weight loss. This information should be useful in counseling new or prospective mothers and in avoiding unrealistic expectations.
Schools represent an important environment for physical activity (PA) promotion among youth. Schools can promote PA through policies and programs but our understanding of how these school characteristics associate with student PA levels is largely unknown. Developing this understanding is critical for implementing new prevention interventions. The aim of this study was to identify the school- and student-related characteristics associated with moderate and high levels of PA in a sample of Ontario elementary schools.
Using multi-level logistic regression analyses, we explored the school- and student-level characteristics associated with being moderately and highly active using data collected from administrators and from students in grades 5 to 8 at 30 elementary schools in Ontario. Students' PA levels, sex, grade, and the number of physical education classes per week were linked to school environment data--specifically, a school's chosen implementation model for daily physical activity and whether it offers intramural and interschool PA programming.
Findings indicate that there was significant between-school variation for being moderately and highly active. Students were less likely to be moderately or highly active if they attended a school offering interschool PA programming. An important student characteristic positively associated with student PA levels included participating in at least two physical education classes per week.
The residual differences in PA by school suggest that school-level characteristics facilitate higher levels of student PA beyond individual-level factors. Although most variation in student PA lies between students within schools, there is sufficient between-school variation to be of interest to practitioners and policy-makers.