Search results for "Lactate"
showing 10 items of 363 documents
O6-methylguanine-DNA methyltransferase activity in breast and brain tumors.
1995
The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is a main determinant of resistance of tumor cells to the cytostatic activity of chemotherapeutic alkylating agents (methylating and chloroethylating nitrosoureas) and is effective in protecting normal cells against genotoxic and carcinogenic effects resulting from DNA alkylation. Therefore, the level of expression of MGMT is significant for the response of both the tumor and the non-target tissue following application of nitrosoureas in tumor therapy. To determine the expression of MGMT in tumor tissue, we have assayed MGMT activity in 68 breast carcinomas and 38 brain tumors. There was a wide variation of MGMT expression…
Relationships between recall of perceived exertion and blood lactate concentration in a judo competition
2001
Relationships between perceived exertion and blood lactate have usually been studied in laboratory or training contexts but not in competition, the most important setting in which sports performance is evaluated. The purpose of this study was to examine the relationships between psychological and physiological indices of the physical effort in a competition setting, taking into account the duration of effort. For this, we employed two Ratings of Perceived Exertion (RPE and CR-10) and lactic acid plasma concentration as a biological marker of the effort performed. 13 male judo fighters who participated in a sports club competition provided capillary blood samples to assay lactate concentrat…
Red cell enzyme polymorphisms in Bulgaria.
1972
7 human red cell enzyme polymophisms have been typed on a sample of n=138 unrelated adults from Bulgaria, which revealed the following gene frequencies: ADA1=0.8623. ADA2=0.1376; AK1=0.9637, AK2=0.0362; 6-PGDA=0.9891, 6-PGDC=0.0108; PGM11=0.8346, PGM12=0.1653; PA=0.1596, PB=0.7983, PC=0.0420. In the LDH-system one B-subunit variant was found, whilst no Peptidase A or B variant could be observed. The anthropological significance of these findings is discussed.
The relation between cycling time to exhaustion and anaerobic threshold.
1990
This study investigated whether the anaerobic threshold (AnT) could be used to predict prolonged work capacity measured as cycling time to exhaustion (= endurance time) and which factors, in addition to relative exercise intensity, could explain variation in endurance time. Theoretical exercise intensities corresponding to certain endurance times were also calculated. The hyperbolic and exponential functions between cycling time and relative work rate (WR[%]), as well as between cycling time and relative oxygen uptake (VO2[%]) were fitted to the pooled data (n = 45) of 17 subjects. The WR(%) and VO2(%) were expressed as a percentage of the subject's own AnT- and maximum-values. At WR corres…
Warm underwater water-jet massage improves recovery from intense physical exercise
1995
The effects of warm underwater water-jet massage on neuromuscular functioning, selected biochemical parameters (serum creatine kinase, lactic dehydrogenase, serum carbonic anhydrase, myoglobin, urine urea and creatinine) and muscle soreness were studied among 14 junior track and field athletes. Each subject spent, in a randomized order, two identical training weeks engaged in five strength/power training sessions lasting 3 days. The training weeks differed from each other only in respect of underwater water-jet massage treatments. These were used three times (20 min each) during the treatment week and not used during the control week. During the treatment week continuous jumping power decre…
Comparison of the 45-Second/15-Second Intermittent Running Field Test and the Continuous Treadmill Test
2012
Purposes:To compare the physiological responses and maximal aerobic running velocity (MAV) during an incremental intermittent (45-s run/15-s rest) field test (45-15FIT) vs an incremental continuous treadmill test (TR) and to demonstrate that the MAV obtained during 45-15FIT (MAV45-15) was relevant to elicit a high percentage of maximal oxygen uptake (VO2max) during a 30-s/30-s intermittent training session.Methods:Oxygen uptake (VO2), heart rate (HR), and lactate concentration ([La]) were measured in 20 subjects during 2 maximal incremental tests and four 15-min intermittent tests. The time spent above 90% and 95% VO2max (t90% and t95% VO2max, respectively) was determined.Results:Maximal ph…
Mechanical work and efficiency in ergometer bicycling at aerobic and anaerobic thresholds
1987
Internal and external mechanical work, energy consumption and mechanical efficiency were studied in constant-load ergometer bicycling at five different power outputs below, equal to, and above the aerobic (AerT) and anaerobic (AnT) thresholds. The gross, net and true efficiencies of the whole body in five male subjects were calculated. The work against the external load was defined as the external mechanical work. The internal mechanical work was calculated as the sum of the increments of kinetic and potential energy in all body segments by using methods of film analysis. Total energy consumption was measured by combining aerobic and anaerobic energy production. When the power output of the…
Muscle metabolism, blood lactate and oxygen uptake in steady state exercise at aerobic and anaerobic thresholds
1986
Muscle metabolites and blood lactate concentration were studied in five male subjects during five constant-load cycling exercises. The power outputs were below, equal to and above aerobic (AerT) and anaerobic (AnT) threshold as determined during an incremental leg cycling test. At AerT, muscle lactate had increased significantly (p less than 0.05) from the rest value of 2.31 to 5.56 mmol X kg-1 wet wt. This was accompanied by a significant reduction in CP by 28% (p less than 0.05), whereas only a minor change (9%) was observed for ATP. At AnT muscle lactate had further increased and CP decreased although not significantly as compared with values at AerT. At the highest power outputs (greate…
Volatile organic compounds (VOCs) in exhaled breath as a marker of hypoxia in multiple chemical sensitivity
2021
Abstract In the history of diagnostics, breath analysis was one of the first method used until the breakthrough of biochemical testing technology. Today, breath analysis has made a comeback with the development of gas analyzers and e‐noses, demonstrating its power in its applicability for diagnosing a wide range of diseases. The physical basis of multiple chemical sensitivity (MCS), an emerging environmental disease, is difficult to understand because it is based on the scenario of chronic hypoxia, with a complex of chemical compounds that trigger the syndrome and result in multiple symptoms. The aim of this study was to investigate MCS by analyzing exhaled volatile organic compounds (VOCs)…
Exercise intolerance at high altitude (5050 m): critical power and W'.
2011
Abstract The relationship between work rate (WR) and its tolerable duration (tLIM) has not been investigated at high altitude (HA). At HA (5050 m) and at sea level (SL), six subjects therefore performed symptom-limited cycle-ergometry: an incremental test (IET) and three constant-WR tests (% of IET WRmax, HA and SL respectively: WR1 70 ± 8%, 74 ± 7%; WR2 86 ± 14%, 88 ± 10%; WR3 105 ± 13%, 104 ± 9%). The power asymptote (CP) and curvature constant (W′) of the hyperbolic WR–tLIM relationship were reduced at HA compared to SL (CP: 81 ± 21 vs. 123 ± 38 W; W′: 7.2 ± 2.9 vs. 13.1 ± 4.3 kJ). HA breathing reserve (estimated maximum voluntary ventilation minus end-exercise ventilation) was also comp…