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PubMed1979

Plasma lactate accumulation and distance running performance.

Laboratory and field assessments were made on eighteen male distance runners. Performance data were obtained for distances of 3.2, 9.7, 15, 19.3 km (n = 18) and the marathon (n = 13). Muscle fiber composition expressed as percent of slow twitch fibers (%ST), maximal oxygen consumption (Vo2max), running economy (Vo2 for a treadmill velocity of 268 m/min), and the Vo2 and treadmill velocity corresponding to the onset of plasma lactate accumulation (OPLA) were determined for each subject. %ST (R greater than or equal to .47), Vo2max (r greater than or equal to .83), running economy (r greater than or equal to .49), Vo2 in ml/kg min corresponding to the OPLA (r greater than or equal to .91) and the treadmill velocity corresponding to the OPLA (r greater than or equal to .91) were significantly (p less than .05) related to performance at all distances. Multiple regression analysis howed that the treadmill velocity corresponding to the OPLA was most closely related to performance and the addition of other factors did not significantly raise the multiple R values suggesting that these other variables may interact with the purpose of keeping plasma lactates low during distance races. The slowest and fastest marathoners ran their marathons 7 and 3 m/min faster than their treadmill velocities corresponding to their OPLA which indicates that this relationship is independent of the competitive level of the runner. Runners appear to set a race pace which allows the utilization of the largest possible Vo2 which just avoids the exponential rise in plasma lactate.

Adult↗
PubMed1984

Genetic distances between the Utah Mormons and related populations.

Gene frequency data, consisting of six red cell antigen loci, nine electrophoretic systems, and HLA-A and -B are reported for the Utah Mormon population. These are compared statistically to gene frequencies from at U.S. population, 13 European populations, and seven populations from three religious isolates. The Mormon gene frequencies are similar to those of their northern European ancestors. This is explained by the large founding size of the Mormon population and high rates of gene flow. In contrast, the religious isolates (Amish, Hutterites, and Mennonites) show marked divergence from their ancestral populations and each other, due to isolation and random genetic drift. The HLA loci and electrophoretic loci presented here yield sets of genetic distances that are highly correlated (r = .734) and that both correspond closely to the actual geographic distances among the European populations. The genetic distances based on red cell antigen loci correspond less closely to the geographic distances and exhibit lower correlations with both the HLA and electrophoretic loci (r = .524 and r = .565, respectively).

Alleles↗
PubMed1983

[Hemodynamic and humoral changes in long-distance athletes].

Cardiac anatomy and function, and some biohumoral parameters, have been examined in 11 long-distance olympic runners, and in 11 healthy untrained control subjects. Echocardiographic methods and computed reading of tracings were adopted. Long-distance runners were also studied within 2 minutes after the end of a 30 Km race. At rest, the athletes had thicker interventricular septa and, posterior walls, higher left ventricular mass index, larger end-diastolic dimensions, cardiac index and stroke index compared to the untrained subjects (all P less than 0.01). Resting heart rate was lower in runners (P less than 0.01). In runners, competitive exercise test induced significant haemodynamic changes (increases in cardiac index, heart rate, stroke index, ejection fraction [all P less than 0.01], decreases in end-systolic dimensions and peripheral vascular resistance [both P less than 0.01]). After exercise, runners showed massive increases both of norepinephrine and epinephrine serum levels (measured in 4 subjects), an increase, in haematocrit and plasma glucose concentration, and a decrease in plasma potassium concentration (all P less than 0.01). In conclusion, olympic long-distance runners have increased cardiac dimensions and wall thickness at rest as compared with healthy untrained subjects matched for age and resting blood pressure. In the former group, a competitive long-distance test results in marked haemodynamic changes, with massive increase in plasma catecholamine concentration and concomitant reduction in plasma potassium concentration. This combination is potentially hazardous, and warrants further investigation.

Cardiac Output↗
PubMed1983

Distance running improves fitness in asthmatic children without pulmonary complications or changes in exercise-induced bronchospasm.

The effect of a distance running program was studied in 15 children with severe chronic asthma. Following a 6-week control period, the subjects ran four days a week for 6 weeks. The distance was increased gradually to 3.2 km. Clinical status and need for treatment did not change. Episodes of exercise-induced bronchospasm were readily reversed. Fitness improved as measured by the distance run in 12 minutes (P less than .005). Resting pulmonary function did not change. Exercise-induced bronchospasm following a bicycle ergometer stress test under comparable conditions did not change. Ventilatory muscle strength, measured as the maximal inspiratory pressure, and endurance, measured as the sustainable inspiratory pressure, were at a high level initially and did not change. It is concluded that distance running is safe and can increase the fitness of asthmatic children who are receiving adequate therapy.

Adolescent↗
PubMed1982

The distance between the high affinity sites of troponin-C measured by interlanthanide ion energy transfer.

Trivalent lanthanide ions are known to be good substituents for Ca2+ at all four calcium-binding sites of rabbit skeletal troponin-C (TnC). In particular, the visible luminescence of terbium ions bound at the two high affinity sites can be excited via a tyrosine residue. We have carried out energy transfer measurements using Tb3+ as the donor and a number of lanthanide ions as acceptors in order to measure the distance between the two high affinity sites in TnC. Luminescence decay measurements showed that, in the absence of acceptors, TnC-bound Tb3+ decays with a single lifetime of 1.31 ms. In the presence of a good acceptor such as Nd3+, the decay was resolvable into two components of roughly equal amplitude. The first was the same in lifetime as that of TnC-bound Tb3+ alone; the second has a shorter lifetime, presumably due to interlanthanide ion energy transfer. From these lifetimes and published critical transfer distances (Horrocks, W. DeW., Jr., Rhee, M.-J., Snyder, A.P., and Sudnick, D.R. (1980) J. Am. Chem. Soc. 102, 3650-3652), we obtained a distance of 0.92 nm between the two high affinity sites. This distance is consistent with the fact that the two high affinity sites have been located in the COOH-terminal half of TnC and with the proposal that each half of TnC is homologous in structure to parvalbumin (Kretsinger, R. H., and Barry, C. D. (1975) Biochim. Biophys. Acta 405, 40-52).

Animals↗
PubMed1981

[The growth of the basis cranii (distances measured externally and problems of the asymmetry) (author's transl)].

The postnatal linear expansion in the region of skull base at the external cranial side was investigated at 91 skulls (44 adults, 47 children). From the anterior end of the Meatus acusticus externus to some anthropological measuring marks in the orbital region (Ektokonchion, Nasomaxillo-frontale, Dakryon, superior and inferior orbital rim) the growth increases between newborn age and 2 years. There is a phase of rest between 2 and 4 years, a further distance growth between 4 and 7 years, a phase of rest between 7 and 17 years and an increase of distance till the adult age. From the posterior end of the meatus acusticus externus to the Opisthocranion proves a less growth increase between newborn age and 2 years, a great one between 2 and 4 years and in the following time only a less growth of distance. Our results of the problem of asymmetries demonstrate that the lateral orbital rim on the right side stretches more dorsally than on the left side. Generally the posterior measuring distance on the right side is greater than on the left side too. The right Orbitale moreover stands lower on the right than on the left side. Opposite to a line from Basion to the Spina nasalis posterior founded by us also the right Porion stands lower significantly than the left one.

Adolescent↗
PubMed1980

The focus-to-detector distance as a source of systematical errors in the measurement of Chaoul therapy units.

The skin exposure rates measured on 22 Chaoul units in two consecutive years were compared and their variance was analysed. The statistical fluctuation of the ionization method was 3.1% by a factor of about 2 to 2.5 smaller than the variations due to lack of reproducibility of the Chaoul units. The authors observed systematical errors among exposure rate measurement performed at different focus-to-detector distances. The effective source-to-detector distance is different for various ionization chambers. It is the sum of nominal focus-to-detector distance plus a geometrical constant. The geometrical constant is for a particular chamber only to a small extent dependent on the front wall thickness and on the focus-to detector distance. Sufficient standardization of both calibration procedure and construction of ionization chambers may help in avoiding this effect.

Analysis of Variance↗
PubMed1980

Running economy and distance running performance of highly trained athletes.

The purpose of the study was to determine the relationship between running economy and distance running performance in highly trained and experienced distance runners of comparable ability. Oxygen uptake (Vo2) during steady-state and maximal aerobic power (Vo2max) were measured during treadmill running using the open-circuit method. Distance running performance was determined in a nationally prominent 10 km race; all subjects (12 males) placed among the top 19 finishers. The subjects averaged 32.1 min on the 10 km run, 71.7 ml.kg-1.min-1 for Vo2max, and 44.7, 50.3, and 55.9 ml.kg-1.min-1 for steady-state Vo2 at three running paces (241, 268, and 295 m.min-1). The relationship between Vo2max and distance running performance was r = -0.12 (p = 0.35). The relationship between steady-state Vo2 at 241, 268 and 295 m.min-1 and 10 km time were r = 0.83, 0.82, and 0.79 (p < 0.01), respectively. Within this elite cluster of finishers, 65.4% of the variation observed in race performance time on the 10 km run could be explained by variation in running economy. It was concluded that among highly trained and experienced runners of comparable ability and similar Vo2max, running economy accounts for a large and significant amount of the variation observed in performance on a 10 km race.

Adolescent↗
PubMed1994

[The origin of long-distance water supply in the central German area and its significance from a hygienic viewpoint].

By means of the climatic, hydrological and hydrogeological conditions in the middle German area the unfavorable water household also due to anthropogenic influences caused through mining and industry will be described. These conditions have, already in the first half of this century, lead to disadvantages concerning the drinking water supply for the population in this territory. Based on older ideas for improving the water supply in the middle German area the long-distance water supply system Elbaue-Ostharz was built after the 2. world war using the water supplies of the river Bode in the Harz, of the Elbaue as well as water from the Dübener Heide to overcome the bad water supply situation in middle Germany. In this connection the efforts of the public health service for improving the drinking water quality in the former country of Sachsen-Anhalt in the DDR will be described. Due to an increased connection of the population in the middle German area with local central water supplies as well as with the long-distance water supply up to 1990 92% of the population could be supplied with drinking water from central water supplies. Nevertheless it was not possible to manage all problems of drinking water quality up to 1990. These problems concerned local central water supplies due to not existing or inadequate plants for water refinement in waterworks and poor conditions of the drinking water pipe nets. Despite all an increasing improvement of the drinking water could be registered as a result of decrease in drinking water consumption, the shutting of water works with water catchments on hygienic unfavorable places, the refurbishment of water works and the further connection from communes with long-distance water supplies. At present and in future too the long-distance water supply will be necessary for the middle German area to guarantee a sufficient quantity as well as quality of drinking water for the population in this territory.

Germany↗
PubMed1995

Effect of distance and travel time on rural women's compliance with screening mammography: an UPRNet study. Upper Peninsula Research Network.

BACKGROUND: The purpose of this study was to determine whether the distance and time required for rural women to travel for a mammogram is associated with their compliance with screening mammography recommendations. METHODS: Women who were > or = 40 years old and visiting family physician offices for any reason were given a questionnaire regarding their frequency of mammography during the past 4 years, the distance and travel time from their homes to the nearest mammography unit, their attitudes and knowledge about mammography, and demographics. The study was conducted in the 12 family practices of the Upper Peninsula Research Network (UPRNet), a Michigan rural family practice research network. RESULTS: Eighty-eight percent (N = 416) of the women in the study had previously had mammography, but 41% were not compliant with American Cancer Society guidelines regarding mammography screening. After controlling for confounding, none of the measures of travel time or distance were associated with mammography compliance. CONCLUSIONS: In this rural population, mammography compliance is not affected by distance, travel time, or transportation. A population-based study in a more remote area is needed to further explore geographic barriers to mammography compliance among rural women.

Adult↗
PubMed1994

[Padma-28, a herbal preparation, increases walking distance in patients with intermittent claudication].

Thirty-six patients with stable intermittent claudication were randomized in a doubleblind study either to treatment with two tablets of Padma-28 twice daily (containing 340 mg dried herbal mixture composed according to an ancient lamaistic prescription) or placebo for four months. Effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressures, and pain-free and maximal walking distances on a tread-mill. The actively treated group attained a significant increase in pain-free walking distance from 115 m (72-218) to 227 m (73- >1000, p < 0.05). The placebo group did not show significant changes in either pain-free or maximal walking distance. Significant changes in systemic or peripheral blood pressures could not be demonstrated in any of the groups. In conclusion, our study has shown that treatment with Padma-28 over a four month period significantly increases the walking distance in patients with stable intermittent claudication of long duration.

Aged↗
PubMed1994

Differences between anatomical and physiological interpupillary distance.

BACKGROUND: The interpupillary distance (IPD) is usually measured between the centers of the pupils (anatomical IPD) or between the visual axes (physiological IPD). We have investigated the differences between the two methods of measuring IPD. METHODS: A millimeter ruler was used to measure the distance between the nasal and lateral limbus of 400 male Arab subjects (anatomical IPD). An Essilor corneal reflex pupillometer was employed to also measure the inter visual axes distance (physiological IPD) of the same group of subjects. RESULTS: The anatomical IPD is on the average 0.10mm and 0.30mm wider than the physiological IPD at distance and near respectively. The calculated near physiological IPD is significantly different from the measured near physiological IPD. CONCLUSIONS: Although individual differences between anatomical and physiological IPDs could be clinically significant, generally, there is good agreement between the two. It is preferable to employ the monocular components of the physiological IPD in ophthalmic procedures.

Adolescent↗
PubMedDate not supplied

Effect of light-tip distance on polymerization of resin composite.

The inability to place a light tip in close approximation to a resin restoration may affect the resultant polymerization and clinical durability of the restoration. This research measured light intensity at the surface of a resin composite, as well as 2 mm within its bulk, as the tip-to-resin distance is moved from 0 to 10 mm. The polymerization of the resin composite at both locations was measured for the various tip distances using exposure durations of 10, 20, 40, and 60 seconds. Light intensity did not decrease with the inverse square of the tip distance. The polymerization on the surface was greatly dependent upon the duration of exposure. The extent of polymerization 2 mm below the surface was still dependent primarily upon exposure duration, but intensity had a significant affect. For exposure durations of 10, 20, and 40 seconds, a tip distance greater than 4 mm demonstrated a significant decrease in resin polymerization 2 mm below the resin composite surface.

Composite Resins↗
PubMed1993

Considerations for standard chest radiography: the long film-focus distance technique.

The possibility of using long film-focus distance radiography as a new screening method for lung cancer diagnosis was investigated. Long-film focus distance radiography produced exceptionally superior image sharpness suitable for use as clinical photographs, at a distance of about FFD (Film-Focus Distance) 20 m. The effective energy was increased by narrowing the radiation spectrum via an air-filter effect, which may prove useful in reducing radiation exposure dosage. Questionnaire results indicate good visualization of cardiac posterior and trachea shadow regions in the diaphragm. Further study is required regarding methods for stabilizing patient position and synchronization with heart beat and respiration to improve reproducibility.

Humans↗
PubMed1993

Could distance be a proxy for severity-of-illness? A comparison of hospital costs in distant and local patients.

OBJECTIVE: We test the hypothesis that hospital costs, after adjusting for DRG mix, are higher in distant patients than in local patients. DATA SOURCES AND STUDY SETTING: Data were obtained from the Washington State Commission Hospital Abstract Reporting System (CHARS) and included all patients discharged from 15 metropolitan hospitals in the state of Washington during fiscal year 1987 (N = 181,072). STUDY DESIGN: Distant patients were initially defined as those patients residing outside a 15-mile radius of the hospital from which they were discharged; all other patients were considered local. Distance was determined using the patient's residence zip code. Hospital charge, calculated for all patients regardless of payer, served as a proxy for cost and was adjusted using the DRG weight. PRINCIPAL FINDINGS: Average charge (adjusted for DRG weight) was higher for distant patients in all but two hospitals. Overall adjusted charge for distant patients was 15 percent higher (p < .001). This finding persisted when different distances were used to dichotomize distant and local patients. When the 20 most common DRGs were examined individually, little charge difference was found in surgical DRGs that require tertiary center services (tertiary DRGs) and in those DRGs with both moderate and predictable resource use (routine DRGs); the charge difference seemed most prominent in those DRGs with a wide array of possible resource use (heterogeneous DRGs). CONCLUSIONS: Results suggest that patients traveling long distances use more resources and incur higher hospital charges than local patients. This is not accounted for in prospective payment. We postulate that distance might serve in part as a proxy for severity-of-illness.

Catchment Area, Health↗
PubMed1993

Kin-structured migration and isolation by distance.

Classical isolation by distance models predict a negative exponential relationship between genetic similarity and geographic distance. Furthermore, under random spatial differentiation all alleles should reflect the same pattern because migration affects all loci identically. The effect of nonrandom composition of migrant groups (kin-structured migration) on these predictions was investigated using computer simulation. Spatial autocorrelation analysis of the simulated gene frequencies showed a decline in similarity with distance in the kin-structured experiments, as predicted by the isolation by distance model. However, the spatial autocorrelations were lower and the variation among correlograms of different alleles was greater than what would be expected under random migration. These findings suggest caution in inferring specific evolutionary conclusions from empirical spatial patterns.

Biological Evolution↗
PubMed1993

31P-MRS of quadriceps reveals quantitative differences between sprinters and long-distance runners.

Phosphorus-31 nuclear magnetic resonance spectroscopy (31P-MRS) has been used to characterize the spectral pattern of quadriceps muscle at rest for sedentaries (N = 10), sprinters (N = 12), and long-distance runners (N = 10). Intracellular pH (pHi), phosphocreatine (PCr), inorganic phosphate (Pi), phosphodiesters (PDE), adenosine triphosphate (ATP) and total phosphate (Pt), defined as the sum of the areas of PCr, PDE, Pi, and 3 times the beta-ATP resonances, were obtained from all spectra. The pHi and ATP/Pt ratio were the same in the three groups of people studied. The PCr/Pi and PCr/Pt ratios were significantly lower and the Pi/Pt ratio was significantly higher for long-distance runners than for sprinters and sedentaries, while the PDE/Pt ratio was significantly lower for sprinters than for sedentaries and long-distance runners. Furthermore, the PCr concentration for sprinters and sedentaries was significantly higher and the Pi was significantly lower than for long-distance runners. The results obtained in this study can be explained by the accepted differences in fiber type composition between sprint and endurance athletes. We suggest that 31P-MRS at rest could be used to monitor noninvasively the individual adaptive response to training in the metabolic characteristics of the athlete muscle fiber.

Adaptation, Physiological↗
PubMed1997

Relationship of distance run per week to coronary heart disease risk factors in 8283 male runners. The National Runners' Health Study.

BACKGROUND: Official guidelines from the Centers for Disease Control and Prevention and the American College of Sports Medicine state that every adult should accumulate 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week. OBJECTIVE: To examine the dose-response relationship between coronary heart disease (CHD) risk factors and vigorous exercise above the recommended minimum levels to assess whether further benefits accrue. METHODS: Physician-supplied medical data were compared with reported distance run in a national cross-sectional survey of 8283 male recreational runners. RESULTS: Compared with runners who ran less than 16 km (10 miles) per week, long-distance runners (> or = 80 km/wk) showed an 85% reduced prevalence of high-density lipoprotein cholesterol levels that were clinically low (< 0.9 mmol/L [< 35 mg/dL]), a 2.5-fold increased prevalence of clinically defined high levels of high-density lipoprotein cholesterol (ie, > or = 1.55 mmol/L [> or = 60 mg/dL], the level thought to be protective against CHD), a nearly 50% reduction in hypertension, and more than a 50% reduction in the use of medications to lower blood pressure and plasma cholesterol levels. Estimated age-adjusted 10-year CHD risk was 30% lower in runners who averaged more than 64 km/wk than in those who averaged less than 16 km/wk (42 vs 61 events per 1000 men). Each 16-km incremental increase in weekly distance run up to 64 to 79 km/wk was associated with significant increases in high-density lipoprotein cholesterol levels and significant decreases in adiposity, triglyceride levels, the ratio of total cholesterol to high-density lipoprotein cholesterol level, and estimated CHD risk. CONCLUSIONS: Our data (1) suggest that substantial health benefits occur at exercise levels that exceed current minimum guidelines and (2) do not exhibit a point of diminishing return to the health benefits of running at any distance less than 80 km/wk.

Adult↗