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A Rode

Publications and source records attributed to A Rode.

At least 37 records · Page 2Linked to original sources
PubMed1996

CYP2C19 genotyping and associated mephenytoin hydroxylation polymorphism in a Canadian Inuit population.

The CYP2C19-associated oxidation polymorphism of mephenytoin was investigated in an Inuit population living in the high Arctic of Canada. Results were obtained for 152 subjects, of whom 90 were unrelated to first degree relatives. Phenotyping was based on the capillary gas chromatographic determination of the S/R enantiomeric ratio in overnight urine collected after a dose of 100 mg (R,S)-mephenytoin. The phenotype was confirmed by determining the S/R enantiomeric ratio after acid treatment of urine samples, and for some subjects, by determining urinary recovery of 4'-hydroxymephenytoin using capillary electrophoresis analysis. DNA was analysed for the m1 and m2 mutations of CYP2C19. Three of 152 subjects (2.0%; 95% confidence limits: 0.0-4.2%) were phenotypically classified as poor metabolizers (PMs). Genotype analysis characterized three individuals as homozygous, and 28 individuals as heterozygous for the m1 mutation, the remaining individuals being homozygous for the wild-type allele. The genotype of the three PMs was concordant with that of the phenotype. DNA fingerprinting confirmed that these three individuals were genetically unrelated. The allele frequency of the CYP2C19m1 mutation, determined in unrelated subjects, was 0.12 (95% confidence limits: 0.07-0.17). CYP2C19m2 was not detected in this population. Thus, the Canadian Inuit resemble Caucasian rather than Asian populations in both the incidence of PM phenotype and the molecular basis of the polymorphism.

Adolescent↗
PubMed1996

Lung volumes of Igloolik Inuit and Volochanka nGanasan.

BACKGROUND: Acculturation to a 'modern' lifestyle has apparently speeded the aging of FVC and FEV1.0 in the Inuit (6). To test this hypothesis further, we compared lung function between Igloolik Inuit and less acculturated nGanasan in Volochanka. METHODS AND MATERIALS: FVC and FEV1.0 were measured by Stead-Wells spirometer (13.5 L lightweight bell) on 210M and 157F Inuit, and by 7.8 L dry gas wedge spirometer on 80M and 66F nGanasan. Subjects were aged 11-60 years. RESULTS: The Inuit and the nGanasan were both some 10 cm shorter than the urban norms, but the ratio of sitting to standing height was normal. Cigarette smoking began around 13-14 yr, reaching a prevalence of 80% in Inuit males and females, 78% in nGanasan males, and 56% in nGanasan females. Inuit lung volumes exceeded urban norms as children and young adults, but had a steep age coefficient even after excluding subjects with a history of respiratory disease. The nGanasan had smaller lung volumes as young adults, but a less rapid decline of function with age. CONCLUSIONS: High lung volumes in young adults probably reflect the continued physical fitness levels of circumpolar residents. The steep age coefficients for the Inuit cannot be explained simply by aging of a cohort with previous respiratory disease. The nGanasan have little advantage of smoking habits or fitness, but do not have snowmobiles. Operation of these vehicles may increase the inhalation of arctic air, and/or cause vertebral damage with resulting alterations of FVC and FEV1.0.

Adolescent↗
PubMed1995

Growth patterns of Canadian Inuit children. A longitudinal study.

A longitudinal study has examined the growth of height, sitting height, body mass and triceps skinfolds in a sample of Inuit (281 boys and 266 girls) attending the Igloolik school between the years 1981 and 1989. Heights were around the 10th percentile of U.S. norms for 1970. A peak height velocity of 9.2 +/- 2.3 cm/year was reached by girls at 11.3 +/- 0.7 years, and in boys the peak rate of 8.6 +/- 3.7 cm/year was seen at 13.5 +/- 0.8 years. Sitting heights were also low relative to urban norms. Body mass approached the 50th percentile of U.S. norms, giving a large mass for height ratio at all ages. Triceps thicknesses for the girls were around the 10th percentile of urban norms, and in the boys began around the 25th percentile, but dropped steadily to the 5-10th percentile. No significant differences of growth patterns were seen between cohorts formed from students born in the years 1970/72, 1973/74 and 1975/76. However, comparison with earlier cross-sectional surveys in the same community showed a secular trend to greater stature and greater skinfold readings as the community had become acculturated to such features of modern living as mechanized transport and television. There were no systematic differences of growth rates between the summer and the winter seasons, and nutrition was good throughout. We thus conclude that the short stature has an inherited basis. Attention is drawn to the problem of interpreting curves of growth and weight for height in populations with an unusual body build.

Adolescent↗
PubMed1995

Body fat distribution and other cardiac risk factors among circumpolar Inuit and nGanasan.

Secular trends in skinfold thicknesses and body fat distribution were examined in the adult Inuit of Igloolik, N.W.T. through surveys conducted in 1969/70, 1979/80 and 1989/93. Findings were compared with the nGanasan population of Volochanka (Taimir peninsula, Siberia), who were examined in 1992/3. The skinfold readings of the Inuit have increased over the two decades of observation. Currently, the young male Inuit and nGanasan remain relatively thin, but older Inuit men and the women of both populations are now quite obese relative to subjects from Southern Canada. The male Inuit have also developed a centripetal, coronary-prone pattern of fat distribution, with subscapular/triceps skinfold ratios that now exceed averages for southern Canada. The majority of both Inuit and nGanasan are current smokers and many fail to meet minimal standards of aerobic performance. Plasma cholesterol levels are still not very high, but a substantial proportion of the nGanasan are affected by hypertension; their source of animal protein is reindeer meat rather than the marine mammals eaten in Igloolik. Alcohol consumption is also higher in Volochanka than in Igloolik. Action is needed to control smoking, reduce body fat content and increase physical activity if circumpolar populations are not to experience an epidemic of cardiovascular disease.

Aged↗
PubMed1995

Plasma fatty acid profiles of Canadian Inuit and Siberian Ganasan.

Cross-sectional data from 86 male and 59 female coastal Inuit of Igloolik (69 degrees 40'N, 81 degrees W) showed a steep age-related increase in the percentage of plasma n-3 fatty acids, with parallel trends in 20:5 and 22:6 but not 18:3 n-3 fatty acid concentrations. Omega-7 + 9 (p < .001) and omega-9 fatty acid concentrations (P < .001 in M, .008 in F) also decreased with age. A tundra-based Siberian indigenous population (30 male and 11 female nGanasan) had similar percentages of n-3 and n-6 fatty acids to the young Inuit, with little age-related change in either measure. Correlation matrices for the Inuit men showed quite strong negative associations of n-3 fatty acid percentages with total triglycerides (r = .34, p < .001) and phosphatidylcholine/free cholesterol ratio (r = -.36, p < .001). In the Inuit women, n-3 percentages were strongly related to phosphatidylcholine/free cholesterol ratio (r = -.60, p < .001), but not to triglyceride readings. The phosphatidylcholine/free cholesterol ratio was also correlated with n-6 percentages (r = -.55, p < .001). In the nGanasan men, triglyceride levels were correlated with n-6 (r = -.35, p < .050), but the size of the female sample was insufficient to establish useful correlations. The present data suggest that as the younger coastal Inuit are abandoning their traditional country foods, plasma levels of n-3 fall. Reasons why n-3 fatty acid levels are negatively related to the plasma phosphatidyl choline/free cholesterol ratio merit further investigation.

Adult↗
PubMed1995

Modernization of lifestyle, body fat content and body fat distribution: a comparison of Igloolik Inuit and Volochanka nGanasan.

OBJECTIVE: To compare two circumpolar populations at different stages in adoption of a modern lifestyle with respect to body fat content, fat distribution, blood lipids and blood pressures. DESIGN: Cross-sectional comparison between Inuit and nGanasan. SUBJECTS: 141 male and 107 female Inuit (aged 17-49 years) living in the modern settlement of Igloolik (69 degrees 40'N, 81 degrees W) and 38 male and 39 female nGanasan living a more traditional lifestyle in Volochanka (71 degrees N, 94 degrees E). MEASUREMENT: Triceps, subscapular and suprailiac skinfold thicknesses, chest and waist circumferences, blood pressures, plasma total cholesterol, plasma HDL-cholesterol and triglyceride concentrations. RESULTS: Igloolik Inuit now have similar subcutaneous fat readings to their urban counterparts, average values increasing with age from 10 to 16 mm in males, and from 15 to 29 mm in females. In Volochanka, the men retain low readings (6-8 mm), but the women (13-25 mm) almost match their Inuit counterparts. Individual skinfolds, chest and waist circumferences all show substantial correlations with blood pressure (nGanasan > Inuit). The subscapular/triceps ratio is also high (Igloolik, 1.55 to 1.74 in men, 1.06 to 1.15 in women; Volochanka, 1.45 to 1.70 in men and 1.20 to 1.70 in women), but this ratio is only weakly correlated with plasma lipids and blood pressures. CONCLUSIONS: Internal fat deposition may reduce correlations between skinfolds and other cardiac risk factors. Nevertheless, the Inuit have accumulated fat in adopting a modern, sedentary lifestyle, with adverse implications for their future health.

Adolescent↗
PubMed1994

Physiological consequences of acculturation: a 20-year study of fitness in an Inuit community.

Surveys in 1969/1970, 1979/1980, and 1989/1990 assessed physical fitness among adult Inuit living in Igloolik, Northwest Territories, Canada, during a period of rapid acculturation to a sedentary lifestyle. MANOVA for age, cohort, and age-cohort effects indicated significant trends to greater skinfold readings [male (M) and female (F)] and body mass (F only), a lower handgrip and knee extension force (M and F), and lower step test predictions of aerobic power (M and F) in the more recent cohorts, with no change of forced vital capacity, 1-s forced expiratory volume, or hemoglobin level. By 1989/1990, continuing hunters tended to have thicker skinfolds than other villagers, and showed no advantage of aerobic power. The average fitness of the sample when tested in 1989/1990 was comparable with that of sedentary populations in Southern Canada, but a minority of villagers who now practiced regular sport had conserved the high levels of fitness that were observed in 1969/1970. We conclude that the fitness of this community appears to have deteriorated markedly as it has become more sedentary, and we thus recommend that health authorities develop methods of promoting an active lifestyle that are culturally appropriate to the populations of circumpolar settlements.

Acculturation↗
PubMed1994

Mitochondrial DNA variability detected in a single wheat regenerant involves a rare recombination event across a short repeat.

The mitochondrial genome of the selfed progeny of a plant regenerated from long-term somatic tissue culture displays specific structural rearrangements characterized by the appearance of novel restriction fragments. A mitochondrial DNA library was constructed from this selfed progeny in the SalI site of cosmid pHC79 and the novel fragments were subsequently studied. They were shown to arise from reciprocal recombination events involving DNA sequences present in the parental plant. The regions of recombination were sequenced and the nucleotide sequences were aligned with those of the presumptive parental fragments. We characterized an imperfect short repeated DNA sequence, 242 bp long, within which a 7-bp DNA repeat could act as a region of recombination. The use of PCR technology allowed us to show that these fragments were present in both parental plants and tissue cultures as low-abundance sequence arrangements.

Base Sequence↗
PubMed1994

Acculturation and the growth of lung function: three cross-sectional surveys of an Inuit community.

The influence of acculturation to a sedentary lifestyle upon the growth and development of lung volumes has been studied in Inuit children aged 9-19 years. Surveys were conducted in the circumpolar community of Igloolik (69 degrees 40'N, 81 degrees W) in 1969/70, 1979/80 and 1989/90. Over this period, the children showed little change of height or body mass at any given age, but a progressive loss of what initially had been a high level of health-related fitness. The sample for each survey comprised about 70% of children in the chosen age range: in the most recent study 87 males and 65 females. Respiratory data included forced vital capacity, one-second forced expiratory volume, maximal mid-expiratory flow rate (second and third surveys only), smoking habits and respiratory health. In each of the 3 surveys, many of the older children in the community were regular smokers. The average cigarette consumption currently rises progressively to 13 +/- 8 cigarettes/day in 87% of males and 11 +/- 7 cigarettes/day in 95% of females over 17 years of age. Nevertheless, lung volumes show the anticipated increase as a logarithmic function of stature. Furthermore, statistically fitted curves show only minor inter-survey differences in volumes for a given standing height. We thus conclude that the deterioration in other aspects of health-related fitness has not yet influenced the growth and development of respiratory function within this Inuit population.

Acculturation↗
PubMed1994

The ageing of lung function: cross-sectional and longitudinal studies of an Inuit community.

Three surveys (1969/1970, 1979/1980 and 1989/1990) have examined the impact of acculturation to a sedentary lifestyle on the pulmonary function of a circumpolar native Inuit community. The sample comprised more than 50% of those aged 20-60 yrs, most recently 119 males and 92 females. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and maximal mid-expiratory flow (MMEF) were measured by standard spirometric techniques, and information was obtained on smoking habits and health. Multiple regression equations showed that lung function was affected by height and age, but usually not by age squared. Cross-sectional age coefficients for FVC and FEV1 increased over the period 1969/1970 to 1989/1990. Parallel longitudinal trends were seen in FEV1 (males only). Multiple analysis of variance (MANOVA) showed age-decade*cohort effects for FVC and FEV1 (males but not females). Almost all of the population now smoke (mean +/- SD males 13 +/- 8 cigarettes.day-1; females 11 +/- 7 cigarettes.day-1). However, smoking bears little relationship to lung function perhaps due to limited variance in consumption. About a third of the community have physician-diagnosed and/or radiographically visible chest disease, but with little effect upon pulmonary function. We conclude that an apparent secular trend to a faster ageing of lung function in men is not explained by disease or domestic air pollution. Possible factors include increased lung volumes in young adults, greater pack-years of cigarette exposure, nonspecific respiratory disease, increased inspiration of cold air or altered chest mechanics due to operation of high-speed snowmobiles, and loss of physical fitness.

Acculturation↗
PubMed1994

Secular and age trends in the height of adults among a Canadian Inuit community.

The height of adults living in the Inuit settlement of Igloolik (69 degrees 40'N, 81 degrees W) had been determined in three surveys, conducted in the winters of 1969/70, 1979/80 and 1989/90. The Inuit are shorter than the general Canadian population, as surveyed in 1981, the discrepancy amounting to about 11 cm for males, and 9-10 cm for females. The decrease in height over the course of adult life, as seen in cross-sectional data, occurs at approximately the same speed in Igloolik as in Southern Canada. However, the causes of this trend seem to be different. Until the seventh decade of life, the decrease observed in southern Canada is due to a substantial secular trend to an increase of stature. In contrast, the Inuit living in Igloolik have become about 2 cm shorter at any given age over the past 2 decades. The trend to loss of stature is strongest in continuing hunters. In the men, the trauma associated with the operation of high-speed snowmobiles over rough terrain may be an important factor. The women do not drive snowmobiles to any great extent; however, they now carry small children on their back less frequently than in previous decades because of a smaller average family size and the adoption of store-purchased clothing which lacks the traditional amauti. In consequence, they may now be less well protected against a low calcium and vitamin D intake. We conclude that because of this secular trend, cross-sectional surveys currently under-estimate the decrease in height that the Inuit will sustain over the adult lifespan.

Adult↗
PubMed1993

Acculturation and loss of fitness in the Inuit: the preventive role of active leisure.

The association between active leisure pursuits and various indices of fitness has been examined in 165 males aged 13-39 years and 95 females aged 13-29 years, all Inuit residents of the community of Igloolik, NWT (69 degrees 40'N). The active individuals have largely conserved the high level of fitness that characterized the settlement in 1969/70, showing substantial advantages over their sedentary peers in terms of relative aerobic power (27.7%, males, 21.3%, females) and subcutaneous fat (18.3%, males, 5.9%, females), with a lesser trend to advantages of strength (handgrip force, 4.4%, males, 0.8% females; knee extension force, 8.3%, males, 2.0%, females). Much of their continued aerobic fitness can probably be attributed to physical activity although in the boys aged 13-16 years, a further factor is the selection of active leisure pursuits by tall, heavy and early maturing individuals. Both the lower body fat and the larger aerobic power are likely to have positive implications for future health. The current challenge is thus to increase the proportion of physically active villagers beyond the current 18.8% of males and 11.6% of females.

Acculturation↗
PubMed1992

Nuclear genes control changes in the organization of the mitochondrial genome in tissue cultures derived from immature embryos of wheat.

Although the mitochondrial genomes of the Chinese Spring and Aquila varieties of wheat are normally similar in organization, this is not so in tissue cultures initiated from their immature embryos where the mitochondrial genomes of both are rearranged and in different, characteristic, ways. However, the mitochondrial genomes of tissue cultures of reciprocal F1 crosses between these varieties were almost identical to one another, showing that nuclear genes control the rearrangement processes. These rearrangements are either due to the appearance of new structures or else result from changes in the relative amounts of subgenomic components. The severe reduction in the amount of certain molecular configurations in tissue cultures from reciprocal crosses is probably due to the presence of dominant information in the Aquila nuclear genome. Data obtained from tissue cultures initiated from F2 embryos of the cross Aquila x Chinese Spring suggest that at least two complementary genes are involved in this control. In contrast, the presence of new molecular arrangements appears to be under the control of a dominant allelic form of a Chinese Spring gene or genes. Thus, this study demonstrates that at least two sets of nuclear genes control the reorganization of the mitochondrial genome which occurs when tissue cultures are initiated from the immature embryos of wheat.

Blotting, Southern↗
PubMed1992

Cold, fitness and the exercise electrocardiogram. A 20 year longitudinal study of Canadian Inuit.

A 20 year longitudinal study has examined fitness, lung function and exercise electrocardiograms in the Inuit of Igloolik (NWT, 69 degrees 40' N). When first examined (1969/70), an energy expenditure of up to 16 MJ/day was estimated from Kofranyi-Michaelis respirometry. Step test predictions of maximal oxygen intake were also high initially, but values declined progressively with acculturation to a sedentary lifestyle. Throughout the 20 years, right-branch bundle block (RBBB) has been somewhat more prevalent than in southern Canada. The majority of those affected have shown no more than slight R-wave notching. In 1969/70, a few of the more marked cases of RBBB may have been attributable to chronic respiratory disease, but the majority of cases have shown high normal values for both lung function and maximal oxygen intake. We thus conclude that the major cause of RBBB in this community is a ventricular hypertrophy due to the vigorous physical demands of the traditional lifestyle.

Adolescent↗