The association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes.

AIMS: We examined the association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes in a multi-ethnic and socio-economically diverse patient group. METHODS: Medical charts at a Toronto gestational diabetes clinic were reviewed for women with a recorded pregnancy between 1 March 2006 and 26 April 2011. One-hour 50-g glucose challenge test values and postal code data were abstracted. Postal codes were merged with 2006 Canadian census data to compute neighbourhood-level ethnic concentration (% recent immigrants, % visible minorities) and material deprivation (% low education, % low income, single-parent households). We compared women in the highest neighbourhood quintiles for both ethnic concentration and material deprivation with all other women to explore an association between marginalization and diagnostic glucose levels. Multivariate regression models of glucose challenge test values and insulin prescription were adjusted for age, prior gestational diabetes, parity and diabetes family history. RESULTS: Among 531 patients with complete glucose challenge test data (mean 11.94 mmol/l, sd 1.83), those in the most marginalized neighbourhoods had 0.43 mmol/l higher glucose challenge test values (95% CI 0.08-0.78) compared with the rest of the study population. Other factors associated with higher glucose challenge test values were prior gestational diabetes (0.59 mmol/l increment, 95% CI 0.19-0.99) and diabetes family history (0.32 mmol/l increment, 95% CI -0.01 to 0.66). Each additional 1 mmol/l glucose challenge test result was associated with an increased likelihood of being prescribed insulin (odds ratio 1.33, 95% CI 1.17-1.51). CONCLUSIONS: Women living in the most materially deprived and ethnically concentrated neighbourhoods have higher glucose levels at diagnosis of gestational diabetes. They may need close monitoring for timely initiation of insulin.

Type 2 diabetes in Canada: concentration of risk among most disadvantaged men but inverse social gradient across groups in women.

AIMS: To assess sex-specific associations of educational and income levels with Type 2 diabetes mellitus. METHODS: Logistic regression analyses (Canadian Community Health Survey, cross-sectional) adjusted for ethnicity, immigration, urban/rural, overweight/obesity, physical inactivity, smoking, chronic conditions and regular physician. RESULTS: Compared to women with some post-secondary education, Type 2 diabetes was more likely in both high school graduates without post-secondary education [odds ratio (OR) 1.27, 95% confidence interval (CI) 1.07-1.51] and high school non-completers (OR 1.73, 95% CI 1.47-2.04); among men, definitive conclusions in high school graduates without post-secondary education could not be drawn (OR 0.93, 95% CI 0.78-1.12), but Type 2 diabetes was more likely in high school non-completers (OR 1.26, 95% CI 1.08-1.48). Compared to women with the highest income, Type 2 diabetes was three times more likely in the lowest income group (OR 2.90, 95% CI 2.25-3.73), 2.53 times more likely in the low middle income group (OR 2.53, 95% CI 1.98-3.24) and 55% more likely in the high middle income group (OR 1.55, 95% CI 1.20-2.01). Among men, Type 2 diabetes was approximately 40% more likely in both the lowest (OR 1.41, 95% CI 1.10-1.80) and low middle income groups (OR 1.39, 95% CI 1.12-1.71); definitive conclusions in the high middle income group could not be drawn (OR 1.05, 95% CI 0.87-1.28). CONCLUSIONS: In women, Type 2 diabetes increased monotonically with lower educational and income levels; in men, Type 2 diabetes was concentrated in the least educated and least affluent. Our findings support the need for policies and practices that lower diabetes risk among the most disadvantaged women and men and moderately disadvantaged women.

Labour market income inequality and mortality in North American metropolitan areas.

OBJECTIVE: To investigate relations between labour market income inequality and mortality in North American metropolitan areas. METHODS: An ecological cross sectional study of relations between income inequality and working age (25-64 years) mortality in 53 Canadian (1991) and 282 US (1990) metropolitan areas using four measures of income inequality. Two labour market income concepts were used: labour market income for households with non-trivial attachment to the labour market and labour market income for all households, including those with zero and negative incomes. Relations were assessed with weighted and unweighted bivariate and multiple regression analyses. RESULTS: US metropolitan areas were more unequal than their Canadian counterparts, across inequality measures and income concepts. The association between labour market income inequality and working age mortality was robust in the US to both the inequality measure and income concept, but the association was inconsistent in Canada. Three of four inequality measures were significantly related to mortality in Canada when households with zero and negative incomes were included. In North American models, increases in earnings inequality were associated with hypothetical increases in working age mortality rates of between 23 and 33 deaths per 100 000, even after adjustment for median metropolitan incomes. CONCLUSIONS: This analysis of labour market inequality provides more evidence regarding the robust nature of the relation between income inequality and mortality in the US. It also provides a more refined understanding of the nature of the relation in Canada, pointing to the role of unemployment in generating Canadian metropolitan level health inequalities.

The role of nuclear factor-kappaB essential modulator (NEMO) in B cell development and survival.

The transcription factor nuclear factor-kappaB (NF-kappaB) is essential for immune and inflammatory responses. NF-kappaB essential modulator (NEMO) is a scaffolding component of the IkappaB kinase complex required for NF-kappaB activation in vitro. Because NF-kappaB activation is involved in B cell development and function, we set out to determine whether NEMO is required for these processes. NEMO(-/-) mice die very early during embryogenesis, and fetal livers from NEMO(-/-) embryos can not reconstitute either B or T lymphopoiesis in irradiated host mice. We therefore used NEMO(-/-) embryonic stem cells and the OP9 in vitro differentiation system to demonstrate that NEMO is not required for B cell development but plays an important role in B cell survival.

Relation between income inequality and mortality in Canada and in the United States: cross sectional assessment using census data and vital statistics.

OBJECTIVE: To compare the relation between mortality and income inequality in Canada with that in the United States. DESIGN: The degree of income inequality, defined as the percentage of total household income received by the less well off 50% of households, was calculated and these measures were examined in relation to all cause mortality, grouped by and adjusted for age. SETTING: The 10 Canadian provinces, the 50 US states, and 53 Canadian and 282 US metropolitan areas. RESULTS: Canadian provinces and metropolitan areas generally had both lower income inequality and lower mortality than US states and metropolitan areas. In age grouped regression models that combined Canadian and US metropolitan areas, income inequality was a significant explanatory variable for all age groupings except for elderly people. The effect was largest for working age populations, in which a hypothetical 1% increase in the share of income to the poorer half of households would reduce mortality by 21 deaths per 100 000. Within Canada, however, income inequality was not significantly associated with mortality. CONCLUSIONS: Canada seems to counter the increasingly noted association at the societal level between income inequality and mortality. The lack of a significant association between income inequality and mortality in Canada may indicate that the effects of income inequality on health are not automatic and may be blunted by the different ways in which social and economic resources are distributed in Canada and in the United States.

Geographical variation in attitudes towards smoking: findings from the COMMIT communities.

This paper examines the links between attitudes towards cigarette smoking and the social environments of communities involved in the U.S. National Cancer Institute's Community Intervention Trial for Smoking Cessation (COMMIT). Our objective is to identify sources of social-geographic variation in smoking attitudes and norms which can hinder or enhance public health efforts to reduce tobacco use. The analysis had two stages: (1) place (measured as region and community) was identified as an important main effect accounting for individual variation in smoking attitudes independent of smoking status and personal characteristics; (2) case studies of COMMIT sites in North Carolina, Iowa, Washington, New Jersey and New Mexico were conducted to reveal features of the local milieux which could account for variations in smoking attitudes. Some of the place characteristics that we suggest are linked to local attitudes include economic reliance on the tobacco industry, libertarian political orientations, socio-economic conditions, legislative context and ethnic composition. Given the effects of regional and community attributes on individual attitudes towards smoking, we conclude that public health efforts to control smoking should continue to be targeted beyond individual smokers to the broader social environment.

Community Intervention Trial for Smoking Cessation (COMMIT): changes in community attitudes toward cigarette smoking.

The success of the Community Intervention Trial for Smoking Cessation (COMMIT) in changing smoking attitudes is examined by testing two primary hypotheses: (1) the priority of smoking as a public health problem increased more in the intervention communities than in the comparison communities, and (2) norms and values that support non-smoking increased more in the intervention than in the comparison communities. One community within each of 11 matched pairs was randomly assigned to receive a 4-year (1989-92) community-based smoking control intervention. Community attitudes towards smoking were measured primarily by cross-sectional surveys in 1989 (n = 9875) and 1993 (n = 14117) but a cohort (n = 5450) also provided attitude information. The main trial effect was on heavy smokers in the intervention communities who showed significantly more change in their beliefs about smoking as a public health problem. Despite the absence of an intervention-comparison difference, the magnitude of change in community-wide norms and values was related to the level of smoking control activities. In the cohort, light-to-moderate smokers in the intervention communities came to have stronger beliefs about smoking as a serious public health problem. COMMIT's impact on the beliefs of heavy smokers about the seriousness of smoking as a public health problem has important public health implications.

Measuring attitudes towards smoking in the Community Intervention Trial for Smoking Cessation (COMMIT).

We present the development of indices using baseline data from the Evaluation Survey for the Community Intervention Trial for Smoking Cessation (COMMIT). The indices are designed to measure two primary attitude constructs that relate to smoking behavior: beliefs about smoking as a public health problem (SPHP); and norms and values concerning smoking (NVS). Two general approaches to index construction, the rational method and the factor analytic method, were used. Item analysis suggested good internal consistency for both indices (alpha > 0.75). Seven subconstructs emerged from the factor analysis accounting for 55.0% of the total variance. The SPHP and NVS items uniquely identify with four factors and three factors, respectively, confirming the validity of the two indices. Confirmatory factor analyses of a different data set provided further validation. Validity was also assessed by an examination of the relationships between index scores and smoking status. Smokers reported significantly higher scores than non-smokers on the two measures indicating, as anticipated, that smokers have more favorable attitudes towards smoking than non-smokers. These findings suggest that the two a priori constructs of SPHP and NVS are empirically distinguishable components of attitudes towards smoking, and that the indices developed here are reliable and valid measures of those constructs.

Contradictions in women's health care provision: a case study of attendance for breast cancer screening.

Breast cancer screening facilities operated by the Ontario Breast Screening Program (OBSP) have recently been added to the existing geography of diagnostic mammography facilities in hospitals and private clinics in Eastern Ontario. While diagnostic facilities require a physician's referral for access, the new centres offer mammograms by self-referral. Other work has shown the utilization of mammography screening services to be quite low despite widespread acceptance of early diagnosis through mammographic screening as the best method to lower breast cancer mortality. Major findings are that spatial variation does exist in attendance rates in the townships and census tracts surrounding the screening centre. At the regional level, physician referral patterns and the presence of local diagnostic mammography units appear to affect the uptake of screening at the Kingston facility. The individual level analysis confirms the importance of the primary care physician's referral with two-thirds of the client sample indicating that they were referred for screening by their family physician. The sample of clients are also very mobile women who have comparatively greater access to financial resources than other women of screening age. The results of ecological and individual level analyses of attendance at OBSP's Kingston Centre reveal contradictions in the provision of this service. Spatially, the centres follow a location pattern of a much higher order health facility yet women are expected to include screening as part of their routine care. Attenders at the Centre were found to be of higher socioeconomic status, married and have access to a private automobile. The finding that the primary care physician's referral is an important prerequisite for attendance raises questions about the feasibility of providing health care for women which encourages individual responsibility for health within the existing paternalistic health care system.

False-positive thromboscintigram resulting from lymphedema--a roentgen pathological model.

Abnormal thromboscintigrams were observed in patients with lymphatic obstruction. This syndrome was reproduced by surgically ligating the lymphatic drainage of the lower extremity of a dog prior to thromboscintigraphy.

Characterization of a yeast mitochondrial locus necessary for tRNA biosynthesis. Deletion mapping and restriction mapping studies.

Yeast mitochondrial DNA codes for a complete set of tRNAs. Although most components necessary for the biosynthesis of mitochondrial tRNA are coded by nuclear genes, there is one genetic locus on mitochondrial DNA necessary for the synthesis of mitochondrial tRNAs other than the mitochondrial tRNA genes themselves. Characterization of mutants by deletion mapping and restriction enzyme mapping studies has provided a precise location of this yeast mitochondrial tRNA synthesis locus. Deletion mutants retaining various segments of mitochondrial DNA were examined for their ability to synthesize tRNAs from the genes they retain. A subset of these strains was also tested for the ability to provide the tRNA synthesis function in complementation tests with deletion mutants unable to synthesize mature mitochondrial tRNAs. By correlating the tRNA synthetic ability with the presence or absence of certain wild-type restriction fragments, we have confined the locus to within 780 base pairs of DNA located between the tRNAMetf gene and tRNAPro gene, at 29 units on the wild-type map. Heretofore, no genetic function or gene product had been localized in this area of the yeast mitochondrial genome.

Fetal surgery in the primate I. Anesthetic, surgical, and tocolytic management to maximize fetal-neonatal survival.

There are compelling physiologic arguments for correcting certain malformations before birth. Although fetal surgery has been successful in sheep and lower animals, it has proven difficult in primates because the gravid uterus is exquisitely sensitive to induction of preterm labor and abortion. Because the feasibility of fetal intervention can be determined only in a primate model, we have investigated the variables affecting fetal-neonatal survival after fetal surgery in 25 monkeys. As we improved our anesthetic and surgical techniques and refined our tocolytic therapy, mortality fell from 73.3% (11/15) to 20% (2/10). Since spontaneous perinatal loss in 56 controls was 21.4% we can now operate on the late second and early third trimester fetal monkey without increasing maternal or fetal-neonatal mortality. Success in this rigorous model is a requisite for attempted correction of human malformations in utero.

Correction of congenital diaphragmatic hernia in utero. III. Development of a successful surgical technique using abdominoplasty to avoid compromise of umbilical blood flow.

Infants born with congenital diaphragmatic hernia (CDH) die because their lungs are hypoplastic. In the fetal lamb, the lung made hypoplastic by compression with an intrathoracic balloon can, if decompressed in utero, grow and develop enough to permit survival at term. To study the efficacy and feasibility of in utero repair of CDH, we created diaphragmatic hernias in fetal lambs at approximately 100 days gestation and corrected them surgically at approximately 120 days. Repair of the diaphragm with closure of the abdomen resulted in postoperative fetal death in six lambs. Acute studies demonstrated that increased intraabdominal pressure compromises blood flow in the umbilical vein and produces severe fetal distress. When a silastic patch was used to enlarge the abdomen after reduction of the viscera and repair of the diaphragm, six of nine lambs were viable after term delivery. In sacrificed lambs, the lungs were well expanded, mature histologically, and greatly increased in size. Correction of CDH in utero appears physiologically sound and technically feasible.

Correction of congenital diaphragmatic hernia in utero. I. The model: intrathoracic balloon produces fatal pulmonary hypoplasia.

A conical silicone rubber balloon was placed in the left hemithorax of fetal lambs and progressively inflated through an exteriorized catheter over the last trimester. Newborn lambs died of severe respiratory insufficiency, despite maximal resuscitation. The lungs were markedly hypoplastic with greatly reduced parenchymal mass and air capacity. This model of a progressively enlarging intrathoracic mass which produces severe pulmonary hypoplasia and fatal respiratory insufficiency simulates the pathophysiology of congenital diaphragmatic hernia in human neonates.