Publications

PLASMA PROTEIN SCANNING AS A NEW TOOL IN PREVENTIVE CARDIOLOGY

No abstract is provided for this article.

Evidence for a Major Quantitative Trait Locus on Chromosome 17q21 Affecting Low-Density Lipoprotein Peak Particle Diameter

Several lines of evidence suggest that small dense LDL particles are associated with the risk of coronary heart disease. Heritability and segregation studies suggest that LDL particle size is characterized by a large genetic contribution and the presence of a putative major genetic locus. However, association and linkage analyses have thus far been inconclusive in identifying the underlying gene(s).An autosomal genome-wide scan for LDL peak particle diameter (LDL-PPD) was performed in the Québec Family Study. A total of 442 markers were genotyped, with an average intermarker distance of 7.2 cM. LDL-PPD was measured by gradient gel electrophoresis in 681 subjects from 236 nuclear families. Linkage was tested by both sib-pair-based and variance components-based linkage methods. The strongest evidence of linkage was found on chromosome 17q21.33 at marker D17S1301, with an LOD score of 6.76 by the variance-components method for the phenotype adjusted for age, body mass index, and triglyceride levels. Similar results were obtained with the sib-pair method (P<0.0001). Other chromosomal regions harboring markers with highly suggestive evidence of linkage (P< or =0.0023; LOD > or =1.75) include 1p31, 2q33.2, 4p15.2, 5q12.3, and 14q31. Several candidate genes are localized under the peak linkages, including apolipoprotein H on chromosome 17q, the apolipoprotein E receptor 2, and members of the phospholipase A2 family on chromosome 1p as well as HMG-CoA reductase on chromosome 5q.This genome-wide scan for LDL-PPD indicates the presence of a major quantitative trait locus located on chromosome 17q and others interesting loci influencing the phenotype.

Genetics of obesity: an update on molecular markers.

No abstract is provided for this article.

Inclined plate settler for emergency water treatment: final design

Previously we reported on the proof-of-concept and initial optimisation work on an inclined plate settler (IPS) for water treatment in humanitarian situations. Whilst promising results (i.e. effluent turbidity < 5 NTU) were obtained, further work was warranted to better control and design the hydraulic flocculation (floc conditioning) stage of the treatment system. This paper reports on such work. A scaled-down version of the IPS was tested in parallel with several hydraulic flocculation configurations. The first deployment of the IPS is planned for 2015.

Absolute fat mass, percent body fat, and body-fat distribution: which is the real determinant of blood pressure and serum glucose?

Associations of body mass index (BMI), absolute fat mass, percent body fat, and regional fat distribution with concentrations of fasting blood glucose and blood pressure were examined cross-sectionally in 1551 men and women aged 15–79 y from two study centers. Measurements included height, weight, multiple skinfold thicknesses, body density by underwater weighing, and waist and hip girths. Three principal findings emerged: 1) Absolute overall body mass and fat mass were stronger predictors of blood pressure and blood glucose than were relative fat mass, after age, height, and current cigarette-smoking status were adjusted for; 2) when diastolic blood pressure and serum glucose were used as the external validity criteria, densitometry was not a “gold standard” for body composition associated with risk for increased blood pressure and serum glucose; and 3) BMI was as good a predictor of blood pressure and glucose as was any other measure of body fat in nearly all analyses.

Aerobic and Anaerobic Energy Contribution during Maximal Work Output in 90 s Determined with Various Ergocycle Workloads

The aim of this experiment was to evaluate the effect of different workloads on the relative contribution of the various energy delivery systems during a 90-s ergocycle test. Nine male subjects, 22 +/- 1 (mean +/- SD) years of age and weighing 71.4 +/- 6.8 kg, were submitted to a VO2max test, as 10-s test (0.1 kp/kg) and three 90-s tests at different loads (LO: 0.05, ME: 0.075 and HI: 0.1 kp/kg) on an ergocycle. No difference was found between peak power output during the 10-s and HI tests. No differences were observed in the total work output performed during 90 s at different workloads (between 481 and 495 J/kg) as well as in the contribution of aerobic and anaerobic pathways to total energy production. However, VO2max was reached earlier during the ME and HI tests than during the LO test. These results indicate that variation in workload did not influence the total work output and the total contribution of aerobic and anaerobic systems during maximal 90-s ergocycle performances. However, variation in workload had an impact on the relative aerobic and anaerobic contribution at various time points. It is concluded that a 90-s ergocycle test with a resistance of at least 0.1 kp/kg is required to appropriately assess maximal anaerobic power while anaerobic capacity might be measured with workloads as low as 0.05 kp/kg.

1053 Hormonal and metabolic responses to prolonged submaximal exercise in lean and obese men

Lamarche, Benoit; homme, Denis Prud; Bouchard, Claude FACSM; Kranenbarg, Elma Klein; Tremblay, Angelo; Nadeau, André; Després, Jean-Pierre Author Information

KCNC1 Gene Polymorphism and OV2max

0710 The K+ voltage-gated channel of the shaw-related subfamily member 1 (KCNC1) gene (11p15), encodes for a voltage-gated K+ channel that serves as an oxygen sensor in*uencing pulmonary artery smooth muscle (PASM) cells excitability in hypoxic conditions, such as high intensity physical activity. PURPOSE: We examined the hypothesis of association between a G\A transition in the KCNC1 gene and OV2max in the sedentary (SS) and trained (TS) states, as well as in response (Δ) to 20-wk endurance-training (ET). METHODS: Pre- and Post-ET VO2 was measured by progressive exercise tests on a cycle ergometer. The polymorphism was detected by PCR and digestion with MspI in 777 DNA samples from the HERITAGE Family Study (Blacks = 275 and Whites = 502). RESULTS: Genotypic distributions were in Hardy- Weinberg equilibrium. χ2 indicated that genotype frequencies were different between races (P <0.0001) but not between genders (p>0.05). ANCOVA revealed statistically significant genotype effects for SS OV2max (P = 0.04) and TS OV2max (P = 0.01) values adjusted for age, gender and body mass. In Blacks only, homozygotes for the rare A allele had significantly higher SS (2329 ± 44 mL/min) and TS OV2max (2729 ± 45 mL/min) than both GG homozygotes (SS = 2314 ± 40 mL/min; TS = 2683 ± 43 mL/min) and GA heterozygotes (SS = 2241 ± 36 mL/min; TS = 2614 ± 36 mL/min). CONCLUSIONS: These findings suggest that DNA sequence variation in the KCNC1 gene is part of the complex genotype associated with OV2max in the sedentary and trained states in Blacks, but not in Whites. Supported by several grants from NHLBI of NIH, CRC-RCMI #1P20RR11126, and RCMI #G12RR03051.

Comparison of the myocardial effects of desflurane and isoflurane in healthy patients: assessment by continuous oesophageal aortic blood flow echo-Doppler

Experimentally, desflurane causes a moderate positive inotropic effect and a transient increase in arterial pressure with rapid increases in concentration compared with isoflurane. We used a continuous oesophageal aortic blood flow echo Doppler device to study the myocardial effects of equi-anaesthetic concentrations of isoflurane and desflurane in 32 healthy patients undergoing superficial surgery. After induction of anaesthesia with midazolam, etomidate and fentanyl general anaesthesia was maintained in 16 patients with 0.6% end-expired concentration of isoflurane and in 16 patients with 3% end expired concentration of desflurane. Isoflurane induced a rapid decrease in aortic blood flow (ABF) which remained almost stable whereas desflurane induced an early, moderate and transient increase in ABF (1 min after introduction of the halogenated agent, mean ABF was 107 (SD 3)% in the desflurane group vs 95 (9)% in isoflurane group compared with control values before introduction of the inhalation agent; P = 0.005), followed by a marked secondary decrease in ABF. The maximal decrease in ABF reached 71 (15)% of its initial value in the desflurane group compared with 80 (14)% in the isoflurane group (ns). Neither agent caused significant changes in other variables except for PE'CO2 which decreased in both groups. Continuous ABF echo-Doppler monitoring demonstrated an early transient positive inotropic effect of desflurane.

Physical activity level and weight control during pregnancy.

No abstract is provided for this article.

Aging Per Se Does Not Influence Glucose Homeostasis

OBJECTIVE—To assess the effect of age on glucose metabolism by examining 1) glucose metabolism in young and middle-aged subjects when total or regional adiposity is taken into account and 2) in vitro glucose transport in adipose tissue explants from young and middle-aged women paired for total and abdominal adiposity. RESEARCH DESIGN AND METHODS—Study 1: body composition, subcutaneous abdominal and visceral adipose tissue areas, and fasting and oral glucose–stimulated glucose and insulin were measured in 84 young and 81 middle-aged men and in 110 young and 91 middle-aged women. Study 2: glucose uptake in subcutaneous abdominal and visceral adipose tissue explants were measured in eight young and eight middle-aged women. RESULTS—Study 1: young and middle-aged men showed similar subcutaneous abdominal tissue area, whereas fat mass and visceral adipose tissue were greater in middle-aged than in young men (P &amp;lt; 0.01). Fat mass and subcutaneous and visceral adipose tissue areas were greater in middle-aged as compared with young women (P &amp;lt; 0.01). Fasting plasma glucose and the glucose response to an oral glucose tolerance test were significantly higher in middle-aged than in young men and women (P &amp;lt; 0.001). Statistical control for visceral adipose tissue area eliminated the difference seen in glucose response in men and women. Study 2: glucose transport in subcutaneous and omental adipose tissue did not differ between young and middle-aged women. CONCLUSIONS—1) Visceral obesity, more than age per se, correlates with glucose intolerance in middle-aged subjects; 2) aging does not influence in vitro adipose tissue glucose uptake.

Convergence between biological, behavioural and genetic determinants of obesity

No abstract is provided for this article.

Association between serum high-density lipoprotein cholesterol and body composition in adult men.

No abstract is provided for this article.

Familial aggregation of seven-year changes in blood pressure in Canada.

No abstract is provided for this article.

Current understanding of the etiology of obesity: genetic and nongenetic

Four types of human obesities are defined by topography of fat deposition. The focus of the paper is on the genetic determinants and the nongenetic correlates of the first type, which is commonly defined as excess weight-for-height or excess body fat without a particular concentration of fat in a given area of the body. The heritability of fat mass or percent body fat derived from underwater-weighing assessment of body density reaches '�-25% of the age- and gender-adjusted pheno- typic variance. The within-identical-twin-pair resemblance in the response to a standardized overfeeding protocol emphasizes the importance of the genotype in determining individual dif- ferences in body weight and body composition. In this regard, the proneness to store energy primarily as fat or as lean tissue is a major determinant of the response to a caloric sur- plus. Am J C/in Nutr 199l;53:l56lS-5S.

Sex differences in the relationships of abdominal fat to cardiovascular disease risk among normal-weight white subjects

No abstract is provided for this article.

Associations between regional body fat distribution, fasting plasma free fatty acid levels and glucose tolerance in premenopausal women.

FAMILIAL AGGREGATION OF CARDIOVASCULAR RESPONSE TO SUBMAXIMAL EXERCISE IN THE HERITAGE FAMILY STUDY

Cardiovascular reactivity, including responses of systolic blood pressure (SBP) and heart rate (HR) to exercise, has been postulated to be a predictor of future essential hypertension and coronary heart disease. The purpose of this study was to investigate the familial relationship of response of SBP and HR and their product to submaximal cycle ergometer exercise in 474 members of 99 sedentary Caucasian families participating in the HERITAGE Family Study. Familial aggregation due to genetic factors and shared social environment was assessed by analysis of variance and the use of the SEGPATH familial correlation model. Maximal heritability for HR response reached 52% at 50 W and 45% at 60% of maximal oxygen uptake (VO2 max), while estimates for SBP response reached 48% at 50W and 38% at 60% of VO2 max, and the estimates for their product were 56% and 45% at 50 W and 60% of VO2 max, respectively. We conclude that the cardiovascular response to the stress of light-to-moderate-intensity exercise is highly familial and includes a significant genetic component. This research was supported by multiple grants from the NHLBI.