HLA class II and HLA-B27 oligotyping in two Siberian native population groups

Abstract: It was the purpose of this study to better define the frequency of HLA-B27 subtypes and HLA class II alleles among indigenous populations from the eastern tip of the Chukotka Peninsula of Siberia, Russia, which have higher frequencies of HLA-B27 (40%) and spondyloarthropathies (2%) than Caucasian populations and test the hypothesis that these populations are more closely related to Orientals. Siberian Eskimos and Chukchi residing in four coastal villages on the Chukotka Peninsula inhabited by Siberian Eskimos and Chukchi people were examined using oligotyping of the polymerase-chain reaction-amplified second and third exons of the HLA-B27 gene. HLA-class II alleles (DRB1, DQA1 and DQB1) were similarly determined. Of 88 HLA-B27 positive individuals from these villages, all had HLA-B*2705, including the four patients with Reiter's syndrome and the five ankylosing spondylitis, except one Eskimo control who had HLA-B*2702. None had HLA-B*2704, a frequent subtype in Orientals. HLA-class II typing in 70 Siberian Eskimos and 71 Siberian coastal Chukchi revealed HLA-DRB1*0401, DRB1*0802, *0901 and *1402 to account for nearly all the DRB1 alleles found in this population, similar to what has been described in Eskimos in Alaska, but different from Chinese or native Americans in the U.S. The overwhelming majority of the individuals examined had HLA-DQB1*0301, similar to what has been observed in Native Americans. The Siberian Eskimos differed from the coastal Chukchi only in the occurrence of HLA-DRB1*0701, DQA1*0201, DQB1*0201 alleles, which occurred only in the former group. These data suggest that the Chukotka population is genetically more closely related to Caucasians and native Americans and less to other Oriental populations.     

Evaluation of association between 9 genetic polymorphism and myocardial infarction in the Siberian population

AIM: to evaluate association between genetic polymorphism (SNPs) and myocardial infarction (identified in recent GWAS) as markers of high risk of myocardial infarction (MI) in Siberian population. Patients were divided into 2 groups - MI patients and control group (ratio 1:2) and presented the sapmle of population of Novosibirsk (9400 patients, 45-69 years) within international project HAPIEE (Health, Alcohol and Psychosocial factors In Eastern Europe). 200 patients with MI (129 men, 71 women) were included. Control group - individuals without MI (420) matched for age and sex. Genomic DNA was extracted from venous blood by phenol-chloroform extraction. Gene polymorphism of genes tested by real-time PCR according to protocol (probes TaqMan, Applied Biosystems, USA) with the use of ABI 7900HT. The following SNPs were studied: rs28711149, rs499818, rs619203, rs10757278 and rs1333049 (hr. 9), rs1376251, rs2549513, rs4804611, rs17465637. The association of SNP and MI was confirmed for 4 of 9 studied SNPs: rs1333049 (hr. 9), rs10757278 (hr. 9), rs499818 (hr. 6), rs619203 gene ROS1. Heart rate was associated with rs1333049 and rs10757278. Glucose level was associated with rs619203, rs28711149 and rs1376251. Total cholesterol and atherogenic index was associated with rs28711149. For the first time in Russian population the associations of GWAS with myocardial infarction SNPs was detected for rs619203, rs499818, rs1333049 and rs10757278. These genetic markers can be used for assessing the risk of myocardial infarction in Russian population.     

Growth and nutritional status of the Evenki reindeer herders of Siberia

This study examines physical growth and nutritional status in a sample of 478 (247 males; 231 females) Evenki herders of Central Siberia. The Evenki display slow growth in stature and body weight, particularly during late childhood and adolescence. Adult males fall below the U.S. 5th percentiles for both stature and body weight. Adult females are below the 5th percentile for stature and approximate the 15th percentile for weight. Despite their diminutive size, the Evenki appear to have adequate energy reserves, as indicated by their skinfold measurements, which range between the U.S. 15th and 50th percentiles. Among adults, women are relatively heavier and fatter than men and tend to increase in weight and fatness with age. Poor growth in the Evenki does not appear to be directly attributable to limited food availability. Rather, it is hypothesized that elevated metabolic requirements, associated with adaptation to a high latitude ecosystem, are responsible for limiting the amount of energy that is allocated to growth. Relatively high levels of adiposity in adult females appear to be the product of changes in activity patterns and fertility levels that resulted after the collectivization of the Evenki. © 1994 Wiley-Liss, Inc.     

Energetics and reproductive effort

Natural selection favors the optimal allocation of energy and other limiting resources to reproduction. Human reproductive physiology displays characteristic patterns that can be viewed as mechanisms that help optimize reproductive effort in the face of environmental energetic constraints. Female ovarian function is particularly sensitive to energy balance and energy flux, resulting in a synchronization of conception with favorable energetic conditions. Reproductive effort during gestation is highly buffered from environmental energetic constraints, but the duration of gestation and final birthweight are both very sensitive to maternal energy availability. Milk production during lactation is relatively buffered from maternal energetic constraints as well, but the duration of lactational amenorrhea is sensitive to the relative metabolic load of lactation. Male gamete production is very insensitive to energetic constraints, but variation in testosterone production in response to both age and longer‐lasting energetic conditions contributes to the modulation of somatic and behavioral aspects of male reproductive effort, aspects that are more energetically costly for a male. There is also new evidence that testosterone may also help to modulate the trade‐off between male parenting and mating effort. Am. J. Hum. Biol. 15:342–351, 2003. © 2003 Wiley‐Liss, Inc.     

Energetics of cardiac contractions

1. The average resting heat production of a muscle under zero tension is 24.8 mcal/g muscle .min at 20 degrees C. In the majority of muscles examined the resting heat production increases when the resting tension and muscle length are increased.2. The relation between actively developed tension and heat produced is similar to that existing in skeletal muscle. The plot of heat against developed tension can be obtained either by altering muscle length or by varying the stimulus frequency.3. The mean maximum total efficiency work/(work + heat) in the work experiments was 11.6%. The total energy produced (work + heat) correlates with the load rather than with the work done.4. In isotonic contractions more heat is liberated than the heat versus tension plot predicts. This extra heat is load-dependent.     

Energetics of karate kumite

It is speculated that anaerobic metabolism is the predominant source of energy in karate kumite. However, no experimental proof is currently available. The metabolic cost and fractions of aerobic and anaerobic energy of karate kumite fighting were investigated. Ten male nationally or internationally ranked karateka [means (SD) age 26.9 (3.8) years, height 1.80 (0.08) m, mass 77.2 (12.8) kg] performed two to four fights scheduled and judged like a championship. Oxygen uptake was measured continuously with a portable spirometric device. Blood lactate was determined immediately before, and minute by minute after, each fight. Aerobic, anaerobic alactic and anaerobic lactic energy were calculated from oxygen uptake during the fight (VO₂), the fast component of the post-fight oxygen uptake (VO_2PCr) above resting values and changes in blood lactate concentration (Net-BLC), respectively. Altogether, 36 fights lasting 267 (61) s were analysed. The referees decisions caused an activity-to-break ratio of approximately 2:1. VO₂, VO_2PCr, and Net-BLC per fight were 165.3 (52.4) ml^.kg^–1, 32.2 (7.2) ml^.kg^–1and 4.2 (1.9) mmol^.l^–1; the overall energy cost above rest was 334.3 (86.3) kJ per fight. Fractions of aerobic, anaerobic alactic, and lactic energy sources were 77.8 (5.8)%, 16.0 (4.6)%, and 6.2 (2.4)%, respectively. The results indicate a high metabolic rate in karate kumite. However, the acyclic activity profile implies that aerobic metabolism is the predominant source of energy and there is anaerobic supplementation, mainly by high-energy phosphates.     

Adaptation to milking agropastoralism in Chilean goat herders and nutritional benefit of lactase persistence

The genetic trait of lactase persistence (LP) evolved as an adaptation to milking pastoralism in the Old World and is a well‐known example of positive natural selection in humans. However, the specific mechanisms conferring this selective advantage are unknown. To understand the relationship between milk drinking, LP, growth, reproduction, and survival, communities of the Coquimbo Region in Chile, with recent adoption of milking agropastoralism, were used as a model population. DNA samples and data on stature, reproduction, and diet were collected from 451 participants. Lactose tolerance tests were done on 41 of them. The European ?13,910*T (rs4988235) was the only LP causative variant found, showing strong association (99.6%) with LP phenotype. Models of associations of inferred LP status and milk consumption, with fertility, mortality, height, and weight were adjusted with measures of ancestry and relatedness to control for population structure. Although we found no statistically significant effect of LP on fertility, a significant effect (P = 0.002) was observed of LP on body mass index (BMI) in males and of BMI on fertility (P = 0.003). These results fail to support a causal relationship between LP and fertility yet suggest the idea of a nutritional advantage of LP. Furthermore, the proportion of European ancestry around the genetic region of ?13,910*T is significantly higher (P = 0.008) than the proportion of European ancestry genome‐wide, providing evidence of recent positive selection since European–Amerindian admixture. This signature was absent in nonpastoralist Latin American populations, supporting the hypothesis of specific adaptation to milking agropastoralism in the Coquimbo communities.     

Energetics of basic Karate Kata

Knowledge about energy requirements during exercises seems necessary to develop training concepts in combat sport Karate. It is a commonly held view that the anaerobic lactic energy metabolism plays a key role, but this assumption could not be confirmed so far. The metabolic cost and fractional energy supply of basic Karate Kata (Heian Nidan, Shotokan style) with duration of about 30?s were analyzed. Six male Karateka [mean?±?SD (age 29?±?8?years; height 177?±?5?cm, body mass 75?±?9?kg)] with different training experience (advanced athletes, experts, elite athletes) were examined while performing one time and two time continuously the sport-specific movements. During Kata performance oxygen uptake was measured with a portable spirometric device, blood lactate concentrations were examined before and after testing and fractional energy supply was calculated. The results have shown that on average 52?% of the energy supply for one Heian Nidan came from anaerobic alactic metabolism, 25?% from anaerobic lactic and 23?% from aerobic metabolism. For two sequentially executed Heian Nidan and thus nearly doubling the duration, the calculated percentages were 33, 25 and 42?%. Total energy demand for one Kata and two Kata was approximately 61 and 99?kJ, respectively. Despite measured blood lactate concentrations up to 8.1?mmol?l^?1, which might suggest a dominance of lactic energy supply, a lactic fraction of only 17–31?% during these relatively short and intense sequences could be found. A heavy use of lactic energy metabolism had to be rejected.     

Correlates of low serum lipid levels among the Evenki herders of Siberia

This study examines serum lipid levels (total, HDL and LDL cholesterol, and triglycerides) among the Evenki reindeer herders of Central Siberia. Cholesterol and triglyceride levels among the Evenki are low, even relative to other indigenous arctic and herding populations. Total and LDL cholesterol levels are higher in women, while HDL and triglyceride levels are comparable between the sexes. Additionally, residence location (i.e., herding brigade vs. central villages) has a significant influence on men's but not women's total and LDL cholesterol levels. Low lipid levels among the Evenki appear to reflect the maintenance of a traditional lifestyle with high levels of energy expenditure and relatively low levels of fat consumption. Sex differences in lipid levels may be partly attributable to differences in activity patterns, as women have significantly lower levels of energy expenditure than men. © 1994 Wiley-Liss, Inc.     

Energetics and oxygen transport mechanisms in embryos

Abrupt, bilateral destruction of the pre-Bötzinger Complex (preBötC) leads to terminal apnea in unanesthetized goats and rats. In contrast, respiratory rhythm and pattern and arterial blood gases in goats during wakefulness and sleep are normal after incremental (over a month) destruction of >90% of the preBötC. Here, we tested the hypothesis that the difference in effects between abrupt and incremental destruction of the preBötC are a result of time-dependent plasticity, which manifests as anatomic changes at sites within the respiratory network. Accordingly, we report data from histological analyses comparing the brainstems of control goats, and goats that had undergone bilateral, incremental, ibotenic acid (IA)-induced preBötC lesioning. A major focus was on the parafacial respiratory group/retrotrapezoid nucleus (pFRG/RTN) and the pontine respiratory group (PRG), which are sites thought to contribute to respiratory rhythmogenesis. We also studied the facial (FN), rostral nucleus ambiguus (NA), medullary raphé (MRN), hypoglossal (HN), and the dorsal motor vagal (DMV) nuclei. Neuronal counts, count region area (mm²), and neuronal densities were calculated using computer-assisted analyses and/or manual microscopy to compare control and preBötC-lesioned animals. We found that within the ventral and lateral medulla 2 mm rostral to the caudal pole of the FN (presumed pFRG/RTN), there were 25% and 65% more (P < 0.001) neurons, respectively, in preBötC-lesioned compared to control goats. Lesioned goats also showed 14% and 13% more (P < 0.001) neurons in the HN and medial parabrachialis nucleus, but 46%, 28%, 7%, and 17% fewer (P < 0.001) neurons in the FN, NA, DMV, and Kölliker-Fuse nuclei, respectively. In the remaining sites analyzed, there were no differences between groups. We conclude that anatomic changes at multiple sites within the respiratory network may contribute to the time-dependent plasticity in breathing following incremental and near-complete destruction of the preBötC.     

Energetics of kayaking at submaximal and maximal speeds

The energy cost of kayaking per unit distance (C_k, kJ?·?m^?1) was assessed in eight middle- to high-class athletes (three males and five females; 45–76?kg body mass; 1.50–1.88?m height; 15–32 years of age) at submaximal and maximal speeds. At submaximal speeds, C_k was measured by dividing the steady-state oxygen consumption (V˙O₂, l?·?s^?1) by the speed (v, m?·?s^?1), assuming an energy equivalent of 20.9?kJ?·?l O^?1 ₂. At maximal speeds, C_k was calculated from the ratio of the total metabolic energy expenditure (E, kJ) to the distance (d, m). E was assumed to be the sum of three terms, as originally proposed by Wilkie (1980): E?=?AnS?+?αV˙O_2max?·?t?αV˙O_2max?·?τ(1?e ^?t·τ?1), were α is the energy equivalent of O₂ (20.9?kJ?·?l?O₂ ^?1), τ is the time constant with which V˙O_2max is attained at the onset of exercise at the muscular level, AnS is the amount of energy derived from anaerobic energy utilization, t is the performance time, and V˙O_2max is the net maximal V˙O₂. Individual V˙O_2max was obtained from the V˙O₂ measured during the last minute of the 1000-m or 2000-m maximal run. The average metabolic power output (E˙, kW) amounted to 141% and 102% of the individual maximal aerobic power (V˙O_2max) from the shortest (250?m) to the longest (2000?m) distance, respectively. The average (SD) power provided by oxidative processes increased with the distance covered [from 0.64 (0.14) kW at 250?m to 1.02 (0.31) kW at 2000?m], whereas that provided by anaerobic sources showed the opposite trend. The net C_k was a continuous power function of the speed over the entire range of velocities from 2.88 to 4.45?m?·?s^?1: C _k ?=?0.02?·?v ^2.26 (r?=?0.937, n?=?32).     

Energetics of activation in frog and toad muscle

1. If activation heat reflects the operation of the calcium pump it should be independent of actomyosin activity. The semitendinosus preparation affords a technique for removing actomyosin activity since the muscle can be stretched till there is almost no overlap between the filaments.2. Heat production, H, in twitches and tetani of stretched muscle fits the relation H = A+M.P/P(ot) where P/P(ot) is the fraction of the optimal tension remaining at the stretched length and A and M are assumed to be the activation dependent and actomyosin dependent heat components.3. For twitches the A component is early and fast and constitutes 0.26 (S.D. 0.09) of the heat production at normal muscle lengths. Its time course is similar in both frog and toad muscle although both M and P are twofold slower in toad muscle. High concentrations of CO(2) slow only M and P(ot). The A component is associated with a normal recovery heat.4. The twitch-tetanus tension ratio, after correction for the extra shortening that occurs during a tetanus, does not vary with the degree of muscle stretch: it is thus probable that twitch activation does not vary with muscle stretch.5. Moderately hypertonic Ringer solution reduces M and P(ot) but not A, but strongly hypertonic solution also reduces A. Zn(2+), No(3) (-) and second shock potentiation of a twitch increase A, M and P(ot) in proportion to each other.     

Energetics of relaxation in frog muscle

1. Changes in the levels of phosphocreatine (PCr) and ATP during relaxation after tetanic contraction have been observed and compared with the heat + work production during the same period.2. The results were the same using 2 sec or 15 sec tetani and using 15 or 30 Hz stimulation.3. During relaxation the mean chemical change (of ATP + PCr) was -0.105 +/- 0.078 mumol/g muscle (n = 53). This change is less than would be required to explain the heat + work produced.4. The PCr split during both 2 sec and 15 sec tetani (up to the last stimulus) was less than would be required to explain the heat + work produced. This confirms previous experiments.5. It is concluded that the discrepancy between chemical change and heat + work production does not diminish during relaxation but actually increases.     

Energetics of locomotion in African pygmies

Summary The energy cost of walking (C _w). and running (C _r), and the maximal O₂ consumption (VO_2max) were determined in a field study on 17 Pygmies (age 24 years, SD 6; height 160 cm, SD 5; body mass 57.2 kg, SD 4.8) living in the region of Bipindi, Cameroon. TheC _w varied from 112 ml·kg^–1·km^–1, SD 25 [velocity (), 4 km·h^–1] to 143 ml·kg^–1·km^–1, SD 16 (, 7 km·h^–1). Optimal walking was 5 km·h^–1. TheC _r was 156 ml·kg^–1·km^–1, SD 14 (, 10 km·h^–1) and was constant in the 8–11 km·h^–1 speed range. TheVO_2max was 33.7 ml·kg^–1· min^–1, i.e. lower than in other African populations of the same age. TheC _r andC _w were lower than in taller Caucasian endurance runners. These findings, which challenge the theory of physical similarity as applied to animal locomotion, may depend either on the mechanics of locomotion which in Pygmies may be different from that observed in Caucasians, or on a greater mechanical efficiency in Pygmies than in Caucasians. The lowC _r values observed enable Pygmies to reach higher running speeds than would be expected on the basis of theirVO_2max.     

Energetics of meal patterns in rats

Meal patterns in rats were examined as functions of the caloric density and availability of the diet. Three diets were used, a standard laboratory diet (3.6 kcal/g), a calorically diluted diet (2.7 kcal/g), and a calorically concentrated diet (4.5 kcal/g). After obtaining ad lib measures of meal patterns on each diet availability of food was constrained by requiring the rats to complete fixed ratio requirements of barpresses to obtain access to a meal. On all 3 diets, meal frequency decreased, while meal size and duration increased as functions of the ratio requirement. Under ad lib conditions and low ratio requirements, in comparison to the standard diet, meal frequency was greater on the diluted diet and less on the concentrated diet. Meal size did not vary as a function of diet on low ratio schedules. At high ratio requirements, rats continued to maintain caloric intake on the diluted diet by increasing meal frequency. On the concentrated diet, however, rats maintained intake at high ratio values by decreasing meal size rather than meal frequency. The results indicate that the rat can adopt a variety of strategies to solve the problem of controlling energy intake constant across the daily feeding cycle.