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Biomedical subjects

H Spielvogel

Publications and source records attributed to H Spielvogel.

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

Muscle tissue adaptations of high-altitude natives to training in chronic hypoxia or acute normoxia.

Twenty healthy high-altitude natives, residents of La Paz, Bolivia (3,600 m), participated in 6 wk of endurance exercise training on bicycle ergometers, 5 times/wk, 30 min/session, as previously described in normoxia-trained sea-level natives (H. Hoppeler, H. Howald, K. E. Conley, S. L. Lindstedt, H. Claassen, P. Vock, and E. R. Weibel. J. Appl. Physiol. 59: 320-327, 1985). A first group of 10 subjects was trained in chronic hypoxia (HT; barometric pressure = 500 mmHg; inspired O2 fraction = 0.209); a second group of 10 subjects was trained in acute normoxia (NT; barometric pressure = 500 mmHg; inspired O2 fraction = 0.314). The workloads were adjusted to approximately 70% of peak O2 consumption (VO2peak) measured either in hypoxia for the HT group or in normoxia for the NT group. VO2peak determination and biopsies of the vastus lateralis muscle were taken before and after the training program. VO2peak in the HT group was increased (14%) in a way similar to that in NT sea-level natives with the same protocol. Moreover, VO2peak in the NT group was not further increased by additional O2 delivery during the training session. HT or NT induced similar increases in muscle capillary-to-fiber ratio (26%) and capillary density (19%) as well as in the volume density of total mitochondria and citrate synthase activity (45%). It is concluded that high-altitude natives have a reduced capillarity and muscle tissue oxidative capacity; however, their training response is similar to that of sea-level residents, independent of whether training is carried out in hypobaric hypoxia or hypobaric normoxia.

Acclimatization↗
PubMed1996

Lactate and epinephrine during exercise in altitude natives.

We tested the hypothesis that the reported low blood lactate accumulation ([La]) during exercise in altitude-native humans is refractory to hypoxianormoxia transitions by investigating whether acute changes in inspired O2 fraction (FIo2) affect the [La] vs. power output (W) relationship or, alternatively, as reported for lowlanders, whether changes in [La] vs. W on changes in FIo2 are related to changes in blood epinephrine concentration ([Epi]). Altitude natives [n = 8, age 24 +/- 1 (SE) yr, body mass 62 +/- 3 kg, height 167 +/- 2 cm] in La Paz, Bolivia (3,600 m) performed incremental exercise with two legs and one leg in chronic hypoxia and acute normoxia (AN). Submaximal one- and two-leg O2 uptake (Vo2) vs. W relationships were not altered by FIo2. AN increased two-leg peak Vo2 by 10% and peak W by 7%. AN paradoxically decreased one-leg peak Vo2 by 7%, whereas peak W remained the same. The [La] vs. W relationships were similar to those reported in unacclimatized lowlanders. There was a shift to the right on AN, and maximum [La] was reduced by 7 and 8% for one- and two-leg exercises, respectively. [Epi] and [La] were tightly related (mean r = 0.81) independently of FIo2. Thus normoxia attenuated the increment in both [La] and [Epi] as a function of W, whereas the correlation between [La] and [Epi] was unaffected. These data suggest loose linkage of glycolysis to oxidative phosphorylation under influence from [Epi]. In conclusion, high-altitude natives appear to be not fundamentally different from lowlanders with regard to the effect of acute changes in FIo2 on [La] during exercise.

Adult↗
PubMed1995

Developmental, genetic, and environmental components of aerobic capacity at high altitude.

The aerobic capacity of 268 subjects (158 males and 110 females) was evaluated in La Paz, Bolivia situated at 3,750 m. The sample included 1) 39 high altitude rural natives (all male); 2) 67 high altitude urban natives (32 male, 35 female); 3) 69 Bolivians of foreign ancestry acclimatized to high altitude since birth (37 male, 32 female); 4) 50 Bolivians of foreign ancestry acclimatized to high altitude during growth (25 male, 25 female); and 5) 42 non-Bolivians of either European or North American ancestry acclimatized to high altitude during adulthood (25 male, 18 female). Data analyses indicate that 1) high altitude urban natives, acclimatized to high altitude since birth or during growth, attained higher aerobic capacity than subjects acclimatized to high altitude during adulthood; 2) age at arrival to high altitude is inversely related to maximum oxygen consumption (VO2 max) expressed in terms L/min or ml/min/kg of lean body mass, but not in terms of ml/min/kg of body weight; 3) among subjects acclimatized to high altitude during growth, approximately 25% of the variability in aerobic capacity can be explained by developmental factors; 4) as inferred from evaluations of skin color reflectance and sibling similarities, approximately 20 to 25% of the variability in aerobic capacity at high altitude can be explained by genetic factors; 5) except among the non-Bolivians acclimatized to high altitude during adulthood, the aerobic capacity of individuals with high occupational activity level is equal to the aerobic capacity of high altitude rural natives; and 6) the relationship between occupational activity level and aerobic capacity is much greater among subjects acclimatized to high altitude before the age of 10 years than afterwards. Together these data suggest that the attainment of normal aerobic capacity at high altitude is related to both developmental acclimatization and genetic factors but its expression is highly mediated by environmental factors, such as occupational activity level and body composition.

Acclimatization↗
PubMed1995

Maximal exercise performance in chronic hypoxia and acute normoxia in high-altitude natives.

Maximal O2 uptake (VO2max) was determined on a bicycle ergometer in chronic hypoxia (CH) and during acute exposure to normoxia (AN) in 50 healthy young men who were born and had lived at 3,600 m altitude (La Paz, Bolivia). VO2max was significantly improved (approximately 8%) by AN. However, the difference in VO2max measured in CH and AN (delta VO2max) was lower than that reported in sea-level natives (SN) who exercised in chronic normoxia and acute hypoxia. It is shown that high-altitude natives (HN) and SN have a similar VO2max in normoxia, but highlanders can attain a greater VO2max when O2 availability is reduced by altitude exposure. In addition, in HN, the higher the subject's VO2max in hypoxia, the smaller his delta VO2max. These results contrast with the data obtained in 14 lowlanders acclimatized to high altitude who showed that their delta VO2max was positively related to their VO2max in hypoxia, as previously reported in SN who exercised in acute hypoxia (A. J. Young, A. Cymerman, and R. L. Burse. Eur. J. Appl. Physiol. Occup. Physiol. 54: 12-15, 1985). Furthermore, arterial O2 saturation of HN behaved differently from acclimatized lowland natives, inasmuch as it fell less during exercise both in CH and AN. HN with high aerobic capacity display a lower exercise ventilation and a reduced arterial saturation, which could explain their inability to improve VO2max with normoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1995

Training in hypoxia vs. training in normoxia in high-altitude natives.

To determine the interactions between endurance training and hypoxia on maximal exercise performance, we performed a study on sedentary high-altitude natives who were trained in normoxia at the same relative (n = 10) or at the same absolute (n = 10) intensity of work as hypoxia-trained subjects (n = 10). The training-induced improvement of maximal oxygen uptake (VO2max) in hypoxia-trained subjects was similar to that obtained in normoxia-trained sea-level natives submitted to the same training protocol (H. Hoppeler, H. Howald, K. Conley, S. L. Lindstedt, H. Claassen, P. Vock, and E. W. Weibel. J. Appl. Physiol. 59: 320-327, 1985). Training at the same absolute work intensity in the presence of increased oxygen delivery failed to provide a further increase in VO2max. VO2max was not improved to a greater extent by simultaneously increasing absolute work intensity and O2 delivery during the training sessions. In addition, training in normoxia is accompanied by an increased blood lactate accumulation during maximal exercise, leading to greater drops in arterial pH, bicarbonate concentration, and base excess. We conclude that, in high-altitude natives, 1) training at altitude does not provide any advantage over training at sea level for maximal aerobic capacity, whether assessed in chronic hypoxia or in acute normoxia; 2) VO2max improvement with training cannot be further enhanced by increasing O2 availability alone or in combination with an increased work intensity during the exercising sessions; and 3) training in normoxia in these subjects results in a reduced buffer capacity.

Adult↗
PubMed1995

Applications of random PCR.

Since the technique of PCR was developed in 1985 (Saiki et al). many new forms of applications have been described in the literature. Of particular interest are PCR approaches, allowing amplification of unknown sequences. In this review these approaches are generally termed "Random PCR"s. While "conventional PCR" in the form that was first described by Saiki et al. is utilized for the amplification and subsequent detection of specific DNA sequences, which are precisely characterized in length and sequence, Random PCR is either used for universal amplification of prevailing DNA or for amplification of unknown intervening sequences which are not generally defined in length or sequence. We depict criteria for discrimination between conventional PCR and Random PCR. Furthermore, we have compiled a classification system for Random PCR approaches based on differentiation by primer structure (degenerate--non-degenerate). According to this classification system a general overview of published Random PCR approaches is given. Future aspects of application of Random PCR are mentioned and commented. Own investigations, combining Random PCR with the technique of chromosome microdissection and thus allowing characterization of unknown chromosomes or chromosome fragments via FISH, are presented. Results are briefly summarized.

Base Sequence↗
PubMed1994

Total lung capacity in young highlanders of Aymara ancestry.

Total lung capacity (TLC) and its components, including residual volume (RV) and vital capacity (VC), are described in a sample of 164 male and 143 female youths of Aymara ancestry (10.0-19.9 years) who were born and raised at high altitudes (> 2,500 m) and who were residing in La Paz, Bolivia (average altitude of about 3,600 m). The hypothesis was tested that the enhanced lung volumes of adult highlanders are attained during the period of growth and development. As found in adult male highlanders, TLC in young highlanders was significantly larger than in lowlanders of the same sex and body size, primarily as a result of increases in RV and secondarily through increases in VC. In addition, estimates of the magnitude of the effect of chronic hypobaric hypoxia on all of the measures of pulmonary function, including TLC, RV, and VC, were positively related to age. This finding suggests that growth and development at high altitude is associated with a constant increase in TLC and other measures of pulmonary function relative to those of lowlanders, a finding which is consistent with the expectations of the developmental adaptation hypothesis. However, although these relationships were statistically significant in males, they were not significant in females. Thus, although the magnitude of the estimated effects of chronic hypobaric hypoxia on TLC, RV, and VC were similar in males and females, the developmental pattern by which these enhanced volumes are achieved may differ between sexes.

Adolescent↗
PubMed1994

Evaluation of physical fitness from field tests at high altitude in circumpubertal boys: comparison with laboratory data.

Field tests of running and laboratory tests were performed in La Paz [high altitude (HA), 3700 m] and in Clermont-Ferrand [low altitude (LA), 300 m] to investigate their validity at HA. Prepubertal boys of mean ages 10.6 years (HA1, n = 16; LA1, n = 28) and pubertal boys of 13.7 years (HA2, n = 12; LA2, n = 41) took part in the study. All the boys performed a 30-m sprint (V30m), a 30-s shuttle run (V30s) and a progressive shuttle run test until their maximal aerobic velocity (VmaxSRT). Maximal oxygen consumption was extrapolated from the last test (VO2maxSRT). In the laboratory, the boys performed a force-velocity test (Pmax), a Wingate test (PWing) and a graded test to measure maximal oxygen consumption (VO2maxB; direct method) on a cycle ergometer. At similar ages, there was no significant difference between HA and LA boys for V30m and Pmax. The V30s of HA boys was 3%-4% lower than those of LA boys (P < 0.05); there was no significant difference for PWing. Significant relationships were observed at both altitudes between Pmax (watts per kilogram) and V30m (HA: r = 0.76; LA: r = 0.84) and between PWing and V30s (HA: r = 0.67; LA: r = 0.77); the slopes and the origins were the same at HA and LA. The VO2max, VmasSRT and VO2maxB were lower by 9%, 12% and 20%, respectively, at HA than at LA (P < 0.05). However, the relationships between VO2maxB and VO2maxSRT (litres per minute) at HA (r = 0.88) and at LA (r = 0.93) were identical.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

The effect of acute hypoxia at low altitude and acute normoxia at high altitude on performance during a 30-s Wingate test in children.

The effect of acute hypoxia (FIO2 = 0.137 +/- 0.001) at Low Altitude (LA: Clermont-Ferrand, 330 m) and acute normoxia (FIO2 = 0.306 +/- 0.006) at High Altitude (HA: La Paz, 3600 m) on performance during a 30-s Wingate test has been investigated in prepubertal children (Tanner stage 1). Twenty five boys (LA, n = 10; HA, n = 15) aged from 10.6 to 12.7 years performed two Wingate tests at random: at LA, one in normoxia (ambient air) and one in acute hypoxia and at HA, one in chronic hypoxia (ambient air) and one in acute normoxia. The subjects performed the two tests using the same calibrated cycle ergometer. Peak Power (PP), Mean Power (MP), O2 uptake during the 30 s (VO2) and blood lactate accumulation (delta [L]s) were measured. Compared to normoxia, acute hypoxia at LA did not alter PP (8.0 +/- 1.1 vs 7.9 +/- 1.3 W.kg-1 BW) and MP (6.1 +/- 0.7 vs 6.1 +/- 1.1 W.kg-1 BW). Similarly, compared to chronic hypoxia, acute normoxia at HA did not modify these parameters (PP: 7.4 +/- 1.5 vs 7.3 +/- 1.8; MP: 5.4 +/- 1.2 vs 5.5 +/- 1.1; W.kg-1 BW). VO2 and delta [L]s were neither significantly changed by acute hypoxia at LA (520 +/- 50 vs 550 +/- 60 ml O2; 5.3 +/- 1.7 vs 4.8 +/- 1.7 mmol.l-1) nor by acute normoxia at HA (530 +/- 110 vs 500 +/- 90 ml O2; 3.4 +/- 1.3 vs 3.3 +/- 1.0 mmol.l-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Anthropometry and lung function of 10- to 12-year-old Bolivian boys.

Anthropometric measurements of 23 HAHSES, 44 HALSES, 43 LAHSES, and 28 LALSES boys (see Introduction to this Supplement) are presented here. They include body height (H), body weight (BW), upper arm circumference (UAC), and skinfold thickness taken at four locations. From these measurements, body fat, lean body mass, and body mass index (BMI = BW/H2) were calculated. The degree of maturation was assessed according to Tanner, orchidometry, and by quantification of testosterone in saliva. Lung function data include: vital capacity (VC), forced expired volume per 1 s (FEV1), functional residual capacity (FRC), residual volume (RV), and total lung capacity (TLC). The results show enhanced lung volumes in both HA groups in comparison to LA groups, with HALSES boys having the greatest increase, even though the LSES boys were significantly smaller compared to the HSES boys at both altitudes and their growth was delayed by approximately 2 years. From the anthropometric data it appears that physical growth of prepubertal boys is dependent on SES but not on high-altitude exposure. We tentatively conclude that chronic hypoxia per se does not affect physical growth in prepubertal boys in an Andean environment and that development of lung function is accelerated in relation to linear growth as has been suggested by other authors (15).

Altitude↗
PubMed1994

Effect of chronic hypoxia and socioeconomic status on the maximal oxygen uptake of 10- to 12-year-old Bolivian boys.

The aim of this study was to analyze the effect of altitude and socioeconomic status on the maximal oxygen uptake (VO2max) of prepubertal Bolivian boys. The subjects were 143 prepubertal boys (10 to 11.5 years old) living in La Paz (altitude 3600 m, n = 67) and Santa Cruz de la Sierra (altitude 420m, n = 76). At high altitude, 23 boys were from a high socioeconomic status (HAHSES) and 44 from a low socioeconomic background (HALSES). At low altitude, 29 boys were from a high socioeconomic level (LAHSES) and 47 from a low socioeconomic background (LALSES). Anthropometric characteristics were determined in order to assess the physical growth of the boys. The VO2max was determined from a progressive maximal exercise (direct method). The subjects performed this test using the same cycle ergometer at both high and low altitudes. For the overall anthropometric parameters, there was no significant difference between highland and lowland boys of the same socioeconomic status. However, regardless of altitude, boys from a low socioeconomic background were 2 years behind those from a high socioeconomic background. There was no significant difference for VO2max between boys from high and low socioeconomic backgrounds at HA (HAHSES: 37.2 +/- 5.6; HALSES: 38.9 +/- 6.4 ml.min-1.kg-1 body weight) and at LA (LAHSES: 42.6 +/- 5.4; LALSES: 43.1 +/- 4.9 ml.min-1.kg-1 body weight). The VO2max of highland boys was, on average, 11% lower than that of lowland boys. It appears, therefore, that a difference in socioeconomic status has no effect on the VO2max (ml.min-1.kg-1) of prepubertal children at low altitude as well as the altitude of 3600m.

Altitude↗
PubMed1993

Effect of chronic hypoxia and socioeconomic status on VO2max and anaerobic power of Bolivian boys.

The aim of this work was to analyze the effects of altitude and socioeconomic and nutritional status on maximal oxygen uptake (VO2max) and anaerobic power (P) in 11-yr-old Bolivian boys. At both high (HA) (3,600 m) and low (LA) (420 m) altitudes, the boys were divided into high (HA1, n = 23, LA1, n = 48) and low (HA2, n = 44, LA2, n = 30) socioeconomic levels. Anthropometric characteristics, VO2max, and P [maximal P (Pmax) during a force-velocity test and mean P (P) during a 30-s Wingate test] were measured. Results showed that 1) anthropometric parameters were not different between HA1 and LA1 and HA2 and LA2 boys, but HA2 and LA2 boys were two years behind HA1 and LA1 boys in development; 2) VO2max was not different in boys from the same altitude, but at HA VO2max was 10% lower than at LA (HA1 = 37.2 +/- 5.6, HA2 = 38.9 +/- 6.4, LA1 = 42.5 +/- 5.8, LA2 = 42.5 +/- 5.3 ml.min-1 x kg-1 body wt); and 3) Pmax and P were higher in well-nourished than in undernourished boys, but there was no difference in Pmax and P between HA1 and LA1 and HA2 and LA2 boys (HA1 = 6.8 +/- 1.0, HA2 = 5.5 +/- 0.8, LA1 = 7.1 +/- 1.0, LA2 = 5.3 +/- 0.9 W/kg for Pmax; HA1 = 5.2 +/- 0.8, HA2 = 4.5 +/- 0.9, LA1 = 5.2 +/- 0.7, LA2 = 4.0 +/- 0.6 W/kg for P).(ABSTRACT TRUNCATED AT 250 WORDS)

Altitude↗
PubMed1993

Effects of chronic hypoxia and exercise on plasma erythropoietin in high-altitude residents.

The present study was performed to evaluate the effects of chronic inspiratory hypoxia and its combination with physical exercise on plasma erythropoietin concentration ([EPO]). Eight natives from the Bolivian Plateau were investigated at 3,600 m above sea level at rest as well as during and up to 48 h after exhaustive exercise (EE) and 60 min of submaximal (60%) cycle ergometer exercise (SE). Ten sea-level subjects were used as a control group for resting values. The mean resting plasma [EPO] of the high-altitude group (19.5 +/- 0.7 mU/ml) did not differ from that of the sea-level group (18.1 +/- 0.4 mU/ml) but was higher than would be expected from the relationship between [EPO] and hematocrit at sea level. Five hours after both types of exercise, [EPO] decreased by 2.1 +/- 0.8 (EE, P < 0.01) and 1.6 +/- 0.8 mU/ml (SE, P < 0.05); 48 h after SE, [EPO] increased by 2.6 +/- 0.9 mU/ml (P < 0.05). It is concluded that 1) high-altitude natives need relatively high [EPO] to maintain their high hematocrit and 2) exercise at low basal arterial PO2 does not directly increase plasma [EPO] in high-altitude residents but seems to exert suppressive effects.

Acclimatization↗
PubMed1992

Physical fitness of children resident at high altitude in Bolivia.

In 7-15-yr-old children living in La Paz (Bolivia, altitude 3,700 m) (HA): 1) Maximal oxygen consumption (VO2max) varies from 35 to 45 ml.min-1.kg-1 and maximal heart rate from 188 to 194 beats.min-1. These values are lower than those of their counterparts at low altitude (LA) by 10-20% and 10-15 b.min-1, respectively. 2) The anaerobic metabolism is not affected by chronic hypoxia if the nutritional conditions and pubertal development of HA and LA boys are the same. When related to percent of VO2max, submaximal O2 debts are similar at HA and LA. After supramaximal exercise, maximal O2 debts (45.7 +/- 2.7 vs 45.9 +/- 3.8 ml.kg-1) and blood lactate concentrations (7.6 +/- 0.6 vs 6.5 +/- 0.6 mmol.l-1) are also the same at HA and LA. No differences are observed between the 2 altitudes in ventilatory (60 vs 56% VO2max) and lactate (60 vs 65% VO2max) thresholds. The altitude of La Paz does not alter the anaerobic performance of a force-velocity test (from 6 to 10 W.kg-1) between the ages of 7 to 15 years but reduces by 14-17% the mean anaerobic power developed during a 30-s Wingate test. This decrease could be linked to a lower participation of glycolysis and aerobic metabolism at HA during this test. 3) Poor socio-economic and nutritional conditions do not modify the aerobic performance of boys living in La Paz but lead to lower maximal anaerobic power (from -17% to -25%) when compared with HA boys from a high socio-economic background.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Adrenergic system in high altitude residents.

Heart rate (HR) response to isoproterenol (ISO) infusion (IP) is decreased in normal sea level (SL) natives exposed to high altitude (HA). Since norepinephrine plasma concentration is higher in HA hypoxia, a downregulation of beta-adrenoceptors (beta AR) was evoked. We explored this phenomenon at 3600 m in a HA normal population (HAN) and in polycythemic subjects (HAP). Results are compared to SL natives in normoxia (SLN), and during chronic hypoxia at 4800 m (SLH) (J Appl Physiol 65:1957-1961, 1988). ISO dose required to raise HR by 25 min-1 (I 25) is not different in HAN or HAP group when compared to SLN. Density of beta AR on lymphocytes was 39% and 25% lower in HAN and HAP than in SLN group, respectively. Chronotropic response to IP is similar in SL and HA subjects under their usual environmental conditions, while SL natives show a blunted response under hypoxia, probably due to a decrease in beta AR density. No adrenergic desensitization was found in highlanders. Lower beta AR density in HA groups could be an adaptive mechanism to chronic hypoxia. Polycythemia does not affect this responsiveness.

Adult↗
PubMed1992

Band-specific localization of the microsatellite at D13S71 by microdissection and enzymatic amplification.

Microsatellite DNA consists of tandemly repeated simple DNA sequence motifs, the number of these repeats being polymorphic. These recently described polymorphisms are ubiquitously distributed throughout the human genome and are highly informative, making them ideal markers for linkage analysis. Physical localization of these microsatellites is an important prerequisite for aligning physical and genetic maps. We have physically mapped the microsatellite at D13S71, which has previously been assigned to chromosome 13. Band-specific mapping of D13S71 to the distal part of band 13q32, near 13q33, was achieved by microdissection of GTG-banded chromosomes and subsequent enzymatic amplification with a heminested PCR approach. Analysis of a panel of somatic cell hybrids confirmed this localization. The technique presented may also be useful in a variety of complex mapping situations and whenever the precise localization of very small (as small as 70 bp) DNA probes is necessary.

Base Sequence↗
PubMed1991

Force-velocity and 30-s Wingate tests in boys at high and low altitudes.

The effects of high altitude (HA, 3,700 m) on performance during a force-velocity test (maximal anaerobic power, MAnP) and a 30-s Wingate test (mean power, P) were studied in boys 7-15 yr of age. Forty-seven children acclimatized to HA were compared with 101 living at low altitude (LA, 330 m). They had the same good nutritional status and the same level of physical activities [average 5.4 +/- 1.1 (SD) and 5.2 +/- 1.9 h/wk at HA and LA, respectively]. They performed the two tests using the same calibrated cycle ergometer. For the Wingate test, O2 uptake (VO2) during the 30 s and the peak of blood lactate concentration ([L]p) during the recovery were also measured. No difference in MAnP was observed between HA and LA. P, [L]p, and VO2 were lower at HA. This suggests that the altitude of 3,700 m did not affect the performance of the force-velocity test but reduced that of the Wingate test. This decrease in P was linked to a lower participation of glycolysis and aerobic metabolism. The latter is related to a reduced aerobic performance at HA. In addition, the slopes of the relationships between age and MAnP, P, and [L]p were the same at HA and LA, indicating that chronic hypoxia did not alter the development of the anaerobic metabolism during puberty.

Acclimatization↗