A pilot study of inherited carnitine palmitoyltransferase deficiency as an ethnogenetic risk factor of infant mortality in indigenous populations of the Far North

A common variant of inherited deficiency of type 1A carnitine palmitoyltransferase (CPT1A) first detected in Canadian Inuits has also been detected in the indigenous populations of various regions of Alaska, northern Canada, and Greenland. However, the prevalence of the P479L genotype in neonates has not been evaluated to date. The frequency of the P479L allele in two populations of Taymyr Peninsula (Dolgan-Nganasan and Nenets) has been assessed in the study. Dried blood spots from newborns born in 2010–2013 were collected in two populations: 108 samples were collected from Dolgan-Nganasans (the settlements Syndasko, Kataryk, and Levinskie Peski) and 105 samples were collected from Nganasans (the Nosok settlement). Allelic variants c.1436C/T (rs 80356779) of the carnitine palmitoyltransferase (CPT1A) gene were investigated in these samples. Genotyping for the P479L mutation was based on analysis of restriction fragment length polymorphism. DNA extracted from the dried blood spots was initially amplified using polymerase chain reaction with the following primers: 5’-CTGGCCAGGTTTGGATTTT-3’ and 5’-TCCAGGATGAAGCAGAGAGG-3’. Restriction endonuclease BstMC (SibEnzim, Novosibirsk, Russia) was used for restriction of the amplicons obtained: a 252-bp fragment was obtained after restriction if the subject carried the T-allele, and an 83-bp fragment was obtained if the subject carried the C-allele. There was a distinct difference in the frequency of the P479L genotype between the two populations, with seven heterozygotes identified in the Dolgan-Nganasan population (7/108; 0.07; 95% confidence interval, 0.03–0.13) and no carriers of the mutant gene identified in the Nenets population (0/105), p = 0.006. The frequency of the rare T-allele in the Dolgan-Nganasan population was 0.03. The results of the study support the hypothesis of the influence of the traditional diet and “evolutionary advantage” for carriers of the P479L mutation residing in certain Arctic regions. We assume that a certain increase in the prevalence of the genetic variant P479L in the Dolgan population may be due to proximity of the area of residence to the coast and adherence to a high-fat diet. Furthermore, we believe that our data and the results of similar studies addressing the frequency of the P479L mutation can be successfully used for the analysis of the origin and migration of certain indigenous peoples of the Far North.     

Beta-globin gene cluster haplotypes in two North American indigenous populations

Haplotypes derived from five polymorphic restriction sites were determined in 50 Carrier-Sekani and 70 Mvskoke chromosomes, and the results were integrated with those previously obtained for 11 South American Indian populations. Eleven haplotypes were identified in the Mvskokes, while five were observed in the Carrier-Sekani. As in South American natives, haplotype 2 (+----) and 6 (-++ -+) were the most prevalent among the Mvskoke (46% and 30%, respectively). In the Carrier-Sekani, haplotype 2 was also the most common, but haplotype 5 (-+ -++) was somewhat more frequent (18%) than 6 (12%). High heterozygosities, as well as genetic differentiation, were observed among these two North American and two other South American groups (Mapuche and Xavante). They could be due to non-Indian admixture in the Mvskoke and Mapuche, but the findings in the other two populations require some other type of explanation.     

Comparative study of mesiodistal crown diameters and arch dimensions between indigenous British and Pakistani immigrant populations

Over the last two decades, the United Kingdom has seen an increase in the number of immigrants from the Indian subcontinent, mainly Pakistan. The amount of information that is available regarding parameters such as mesiodistal crown diameters and dental arch dimensions is, however, somewhat limited for this population. An investigation was carried out to compare corresponding mesiodistal crown diameters and arch dimensions between samples of the indigenous British population in Leeds (England) and the Pakistani immigrant population living in Rochdale (England). Measurements were taken from dental casts. The results showed that there were no significant differences between the two ethnic groups in corresponding mesiodistal crown diameters or arch dimensions. Data are provided for the Pakistani immigrant population in Britain.     

Mechanisms of inhibition of vascular-platelet hemostasis by salivary gland secretion of the medicinal leech Hirudo medicinalis

The mechanism of inhibition of the vascular-platelet stage of hemostasis by medicinal leech salivary gland secretion was studied. It was shown that the secretion blocks platelet adhesion on the surface of collagens belonging to different genetic classes, inhibits the primary attachment of platelets and completely suppresses their spreading on collagen surface. Whatever its antithrombin activity, the leech secretion inhibits platelet aggregation stimulated by various inductors, e. g., ADP, prostaglandin endoperoxide analog U-46619, Ca2+ ionophore A23187, arachidonic acid. The secretion possessing the antithrombin activity causes a greater inhibition of the thrombin-stimulated aggregation than that devoid of this activity. Leech secretion stimulates adenylate cyclase of platelet membranes in a receptor-mediated fashion and increases the level of cAMP. The active substance is a low molecular weight, thermostable trypsin-resistant fraction of the secretion. Stimulation of adenylate cyclase is not mediated by adenosine receptors. It is supposed that the mechanism of this activating effect involves platelet prostaglandin receptors.     

Lipids and their correlation with vitamin D in the indigenous populations of Russia European North

The aim of our research was to investigate the level of 25-OH vitamin D in blood plasma of indigenous inhabitants of Russia European North. The study showed that there was wide spreading of vitamin D deficiency among northerners especially in teenager. The significant reduction of 25-OH vitamin D3 was revealed in the inhabitants of Far North in March. It is shown that there is correlation of the vitamin D with total cholesterol, apolipoprotein A, high and low density lipoproteins and vitamin A and E.     

Comparisons of cerebral circulation parameters in schoolchildren living in the Far East and European North

Transcranial Doppler sonography and impedansometry was used to study cerebral circulation in students aged from 7 to 17 living in the North in the "absolute discomfort" area (Magadan region. 62 degrees North, 158 degrees East, n = 167) and "discomfort" area (Arkhangelsk region, 61 degrees North, 41 degrees East, n = 52). New data were obtained about both blood flow parameters in main cerebral arteries, vessels tone and vasomotor reactivity as well as differences between these indices in children from the two northern areas. The results reveal that arterial blood flow velocity (BFV) in cerebral arteries is faster in Koryaks and Evens who are the children of the native population compared to BFV in the children born in the North whose parents represent newcomers. A tendency exists in the form of vascular tone rising in the living in the North students. This tendency is more expressed in children and adolescents from Magadan region which is distinguished from Arkhangelsk region by more severe climate. The indices that characterize individual alterations of cerebral circulation under hypoxic-cold factors as well as population peculiarities related to "polar adaptive type of metabolism" forming are discussed.     

Population parameters of indigenous populations ofMyocastor coypus: the effect of hunting pressure

The coypu or nutriaMyocastor coypus Molina, 1782 is a semiaquatic rodent intensively harvested for fur in its native region. We studied population parameters at four sites differing in hunting pressure and characterised hunting activity in north-eastern Buenos Aires province, Argentina. Our interviews with hunters, local inhabitants and wildlife managers revealed that hunting is a cultural tradition in the countryside with the coypu being used as meat and, fur and the young occasionally used as pets. Quarterly live trapping captured a high proportion of all coypus present at each site. In sites with higher hunting pressure, low density of coypus was associated with high population losses and immigration. I n these sites the proportion of juveniles and pregnant females was similar to that obtained at sites with no hunting pressure. No foraging deficiencies were evident from diet quality analysis. Our results suggest that harvesting determines the dynamics of coypu populations in, this region where hunting pressure can be assessed by accessibility of hunting sites, their distance to urban or rural settlements, effective control of hunting, and human population density of the area.     

Red blood system in 10–12-year-old children of the Far North

Healthy children between the ages of 10 and 12 years (n=699) of the Far North (Taimyr peninsular) and Siberia (Krasnoyarsk city) were examined. The red blood system was investigated relative to the duration of residence in the polar region and the season of the year. The red blood cell (RBC) count and the hemoglobin level in children from the newly arrived population corresponded to the normal age values, and those of the aborigines were at the lower border of the normal value range. The qualitative composition of their red blood was changed—the level of the alkaline-resistant hemoglobin was elevated. In all the children who lived in the polar regions, the mean RBC volume was augmented, along with seasonal dynamics of blood electrolyte composition, changes in phospholipid spectrum of erythrocyte membranes, and certain activation of lipid peroxidation reactions. The oxygen-binding capacity of blood was changed in children from the polar regions, which led to alterations of hemoglobin affinity to O₂ in pO₂ in the direction of its increase in the lungs and decrease in tissues under conditions of existing pO₂. These deviations were the most common (from 5/6 to 2/3) in children during the first five years of their residence in polar regions; afterwards their frequency as compared to the control curve did not exceed 1/2, as in the aborigines.     

Effect of ethyl alcohol on selected parameters of the hemostasis system in vitro]

Alcohol produces several disorders in all components of hemostasis system. However, its mechanism of action is not clear. Therefore, an effect of ethyl alcohol on the selected parameters of both platelet and plasma hemostasis has been examined in vitro. Blood aggregation induced by ADP and PAF and platelet-leucocytic aggregates have been determined in vitro in the group of 45 healthy volunteers. Out of plasma parameters the selected factors of blood coagulation and fibrinolysis have been examined. Results suggest that the examined concentrations of ethyl alcohol mainly affect platelet function decreasing platelet aggregation. Alcohol does not affect significantly blood coagulation and fibrinolysis occurring in vitro.     

Effect of ionizing radiation on the functional state of the vascular-thrombocytic component of the hemostasis system

The influence of ionizing radiation (gamma-rays 60Co) on aggregation activity of the vascular wall and functional (aggregation) platelet activity was studied in the course of the development of acute radiation sickness. The decrease in the aggregation properties of the vascular wall and high functional activity of platelets were inversely proportional, correlating with the periods of acute radiation sickness development and depending on the radiation dose. It is suggested that the changes detected may play a role in the pathogenesis of the development of the postirradiation thrombohemorrhagic syndrome.     

Some parameters of hemostasis in diabetic patients

Parameters of blood coagulation and fibrinolysis in diabetic patients chronically treated with oral hypoglycaemic agents and insulin have been analysed. All examined patients were divided into four subgroups: I-treated with biguanides, II-treated with sulfonylurea derivatives, III-sulfonylurea and biguanide derivatives simultaneously, IV-treated with insulin. Observed decrease in haemostasis parameters and activation of fibrinolysis in patients treated with only biguanides seemed associated with favourable effect of these agents on the decrease in the risk of the thrombotic complications in diabetes mellitus.     

Genetic structure of the indigenous populations of Siberia

This study explores the genetic structure of Siberian indigenous populations on the basis of standard blood group and protein markers and DNA variable number of tandem repeats (VNTR) variation. Four analytical methods were utilized in this study: Harpending and Jenkin's R-matrix; Harpending and Ward's method of correlating genetic heterozygosity (H) to the distance from the centroid of the gene frequency array (r_ii); spatial autocorrelation, and Mantel tests. Because of the underlying assumptions of the various methods, the numbers of populations used in the analyses varied from 15 to 62. Since spatial autocorrelation is based upon separate correlations between alleles, a larger number of standard blood markers and populations were used. Fewest Siberian populations have been sampled for VNTRs, thus, only a limited comparison was possible. The four analytical procedures employed in this study yielded complementary results suggestive of the effects of unique historical events, evolutionary forces, and geography on the distribution of alleles in Siberian indigenous populations. The principal components analysis of the R-matrix demonstrated the presence of populational clusters that reflect their phylogenetic relationship. Mantel comparisons of matrices indicate that an intimate relationship exists between geography, languages, and genetics of Siberian populations. Spatial autocorrelation patterns reflect the isolation-by-distance model of Malecot and the possible effects of long-distance migration. Am J Phys Anthropol 104:177–192, 1997. © 1997 Wiley-Liss, Inc.     

Parasitism and breeding system variation in North American populations of Daphnia pulex

The Red Queen hypothesis proposes that frequency-dependent selection by parasites may be responsible for the evolutionary maintenance of sexual reproduction. We sought to determine whether parasites could be responsible for variation in the occurrence of sexual reproduction in 21 populations of Daphnia pulex (Crustacea; Cladocera) that previous studies have shown to consist of either cyclical parthenogens, obligate parthenogens, or a mixture of both. We measured parasite prevalence over a four-week period (which essentially encompasses an entire season for the temporary snow-melt habitats we sampled) and regressed three different measures of sexuality against mean levels of parasite prevalence. Levels of parasitism were low and we found no relationship between levels of sexuality and mean parasite prevalence. Genetic variation with infection level was detected in 2 of the 21 populations, with several different clones showing signs of overparasitism or underparasitism. Overall, however, our results suggest that parasites are not a major source of selection in these populations and it thus seems unlikely they are responsible for maintaining breeding system variation across the study region.     

Analysis of palm dermatoglyphics in Taiwan indigenous populations

An analysis of a-b and a-d palm ridge counts was made from samples of people in eight indigenous Taiwan populations. Differences between hands, sexes, and populations were all significant. Bimanual differences for both counts were large, and right hand counts were consistently smaller than those for the left hand in all the populations. This is believed to be a consequence of the evolution of development, reflecting some inborn bilateral differences in function and anatomy. Sex differences, although small, were noticed. Variations between populations, ranging from approximately 7 to 19% of the total, were assumed to be genetic. The population relationships, based on dermatoglyphics, partially resembled those based on anthropometric measurements; and some aspects of their evolutionary significance were discussed.     

Estimation of mating system parameters in plant populations using the EM algorithm

Theoretical and Applied Genetics - An EM algorithm procedure is presented for the maximum-likelihood estimation of mating system parameters of mixed mating system models for both angiosperms and...