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Biomedical subjects

F S Apple

Publications and source records attributed to F S Apple.

At least 109 records · Page 6Linked to original sources
PubMed1987

Creatine kinase isoforms following isometric exercise.

The present study assessed creatine kinase (CK) activity, CK MM isoforms, and muscle soreness following an exercise regimen designed to induce skeletal muscle damage. Eight college-age subjects performed 40 maximal isometric contractions of the knee extensor muscles (10-second contraction/20-second rest). Serum samples and soreness ratings were taken prior to and 2, 6, 18, and 24 hours after the exercise. The CK MM1 and CK MM3 isoforms were determined by flatbed isoelectric focusing (IEF). In serum, the MM1 isoform (the pure gene product) is considered to be evidence of newly released CK from muscle, as upon entering the plasma, the CK MM1 is converted to MM2 and then MM3. A significant increase in serum CK activity was found at 6 hours and remained elevated at 24 hours. CK MM1 increased significantly at 2 hours, peaked at 6 hours, then approached baseline. Soreness did not increase significantly until 18 hours. Analysis of CK isoforms in serum can provide an earlier indicator of skeletal muscle damage than total CK or perception of soreness and may be useful in tracking the time course of skeletal muscle damage and repair.

Adult↗
PubMed1987

Skeletal muscle creatine kinase MB alterations in women marathon runners.

Total creatine kinase (CK) and CK MB activities were determined in gastrocnemius muscle and serum obtained from 14 female marathon runners. The level of CK MB in muscle increased significantly (p less than 0.05) after chronic exercise training from 5.3% to 10.5% of the total CK activity, but not after acute exercise (post-marathon 8.9%). No significant differences in total CK activities were detected. However, the total CK activity in the muscles were significantly (p less than 0.05) less than those previously reported from the muscle of men runners (1800 U/g, 3000 U/g respectively). No significant correlation existed between fiber type and muscle CK MB activity. Additionally, trace amounts of mitochondrial CK and CK BB were present in muscle homogenates. A significant correlation was observed in the increase in mean serum total CK (597 UL-1) and CK MB (23 UL-1) activities 24 h after the race (r = 0.97, p less than 0.05). These results suggest that gastrocnemius muscle in women adapts to training with increased CK MB activities and imply that skeletal muscle is the major source of elevated serum CK MB activities in women marathon runners.

Adult↗
PubMed1987

Analyses of creatine kinase isoenzymes and isoforms in serum to detect reperfusion after acute myocardial infarction.

Isoenzymes and isoforms of creatine kinase (CK, EC 2.7.3.2) were measured to assess reperfusion after acute myocardial infarction (AMI). In streptokinase-treated and in spontaneously reperfused AMI patients, total CK, CK-2 activity and concentration, and CK-3(3) isoform activity peaked significantly (p less than 0.05) earlier than conventionally treated, non-reperfused patients. The ratio for CK-3(3) to CK-3(1) activities peaked significantly (p less than 0.05) earlier in both the streptokinase-treated and spontaneously reperfused groups, and indicated a greater release of enzyme (higher ratio) than in the conventionally treated patients. The ratio of CK-3(3)/3(1) also peaked significantly (p less than 0.05) earlier in all three groups than did total CK, CK-2, and CK-3(3) activities or concentrations. The clearance rates of total CK, CK-2, and CK-3(3) were not significantly different in all three groups. Thus, the ratio CK-3(3)/3(1) was the earliest indicator of infarction in both reperfused and non-reperfused patients.

Creatine Kinase↗
PubMed1986

Poor iron status of women runners training for a marathon.

The iron status of nine female marathon runners was evaluated during 11 weeks of training for a marathon race and following a marathon race. Venous blood samples were obtained at the start of the training period, weekly during training, and 1, 2, 3, and 4 days post-race. The subjects completed menstrual and dietary histories, and the diet content of energy, protein, iron, and ascorbic acid was calculated. Serum iron, total iron binding capacity, and transferrin saturation showed no significant change at weeks 1, 7, and 11 during training. The mean values of serum iron and transferrin saturation were low. During training, eight of the nine women averaged serum ferritin levels below 50 ng/ml, one of the eight having values consistently less than 10 ng/ml. Ferritin values were significantly elevated for 3 days after the marathon. No subject reported abnormally heavy menstrual bleeding, and nutrient intakes were near recommended levels, except for iron. Thus, the iron status of these women marathon runners was poor, suggesting that women runners may have higher dietary needs for iron than sedentary women. Serum ferritin levels were also elevated after a marathon run and may not adequately reflect iron stores.

Adult↗
PubMed1986

Skeletal muscle lactate dehydrogenase isozyme alterations in men and women marathon runners.

Total lactate dehydrogenase (LD) and LD isozyme activities in gastrocnemius muscle from trained men and women runners were measured in response to the chronic stress of training for a marathon race (42.2 km). Following 9 wk of training, total LD activity in skeletal muscle from men and women runners significantly (P less than 0.02) decreased 2.26 and 2.25 U/mg protein, respectively. However, men's total LD activities were significantly (P less than 0.001) less than the women's both before and after training. Significant (P less than 0.05) increases in LD1 activities in skeletal muscle in men and women runners were also observed after training. No significant correlations were detected between percent fiber type composition in men or women vs. the changes in total LD activity, changes in LD1 activity, maximal O2 consumption or training distance averaged per week after the training period. The biochemical adaptations in skeletal muscle that occurred in the LD isozyme composition in both men and women runners make the runners skeletal muscle appear similar to heart muscle in LD1 and LD2 activities.

Electrophoresis↗
PubMed1986

Mitochondrial creatine kinase activity alterations in skeletal muscle during long-distance running.

In human gastrocnemius muscle obtained from long-distance runners, mitochondrial creatine kinase (CK) activities were significantly greater than nonrunning control skeletal muscle and significantly increased during training for and after a marathon race. Thus skeletal muscle tended to become similar to heart muscle in its mitochondrial CK composition. Total muscle CK activity was significantly different in males and females, was unaffected by marathon training and racing, and was similar to gastrocnemius muscle obtained from nonrunning controls. There was an inverse correlation between the maximum O2 uptake and the percentage increase in mitochondrial CK activity after training. These studies suggest that mitochondrial CK may play a key role in the intracellular transport of energy from mitochondrial to myofibrils in skeletal muscle during endurance exercise such as long-distance running.

Creatine Kinase↗
PubMed1986

Elevated serum ferritin concentrations in master runners after a marathon race.

To evaluate iron stores in master runners, serum ferritin levels were measured 24 hrs before and 1, 24 and 168 hrs after a 42.2 km marathon race in 12 men and 7 women master runners. Mean ferritin concentrations were 88 and 50 ng/ml, respectively, before the race. Significant elevations in serum ferritin levels were observed 24 and 168 hrs after the race for men runners and 1, 24 and 168 hrs after the race for women runners. Serum ferritin levels elevated after a stressful event like a marathon race may no longer accurately reflect body iron stores.

Adult↗
PubMed1986

Creatine kinase isoenzyme MM variants in skeletal muscle and plasma from marathon runners.

We investigated the patterns of variants of creatine kinase isoenzyme MM (CK-MM) in gastrocnemius muscle and plasma sampled from male and female long-distance runners before and after a marathon race. The proportions of CK-MM variants MM1 (pI 6.90) and MM2 (pI 6.62), identified in the skeletal muscle from both sexes, did not differ significantly from those in skeletal muscle from nonrunning controls or from heart muscle. CK-MM1 was the major (84-85% of total CK-MM) variant form. Patterns of CK-MM in plasma collected from male runners 24, 48, 72, and 96 h after the race were similar to those for female runners, but we detected two new additional variants, which we designate MM1B (pI 6.76) and MM2B (pI 6.49). For both sexes the total CK-MM activities in plasma were significantly (p less than 0.05) greater after the race, but the women's total CK-MM activities were significantly (p less than 0.05) less than the men's. The rates of disappearance of MM1, MM2, and MM3 from plasma after the race differed significantly (p less than 0.05) between men and women, MM1 clearing the fastest. Determination of the CK-MM variants in plasma after strenuous exercise may be of help in assessing CK release from injured skeletal muscle.

Adult↗
PubMed1985

Creatine kinase-MB isoenzyme adaptations in stressed human skeletal muscle of marathon runners.

The creatine kinase (CK) isoenzyme composition was determined in serial gastrocnemius muscle biopsies obtained from 12 male marathon runners. The mean muscle CK-MB composition significantly increased after chronic exercise (training) from 5.3% (pretraining) to 7.7% (premarathon) as well as after acute exercise (postmarathon) to 10.5% of the total CK activity (P less than 0.05). However, no significant differences in total CK activities were detected. Additionally, mitochondrial CK and CK-BB isoenzymes were present in muscle homogenates. A significant correlation was observed in the increase in mean serum total CK (3,322 U/l) and CK-MB (174 U/l) activities 24 h after the race (r = 0.98, P less than 0.05). These results show that gastrocnemius muscle adapts to long-distance training and racing with increased CK-MB activities and imply that skeletal muscle is the major source of elevated serum CK-MB activities in marathon runners.

Adaptation, Physiological↗
PubMed1985

Creatine kinase isoenzyme activities in men and women following a marathon race.

Serum samples from 14 men and 8 women were obtained pre-marathon (48 h) and at 24, 48, 72, and 96 h post-race to quantitate total serum creatine kinase activity (TCK), percentage of creatine kinase MB (CK-MB), and clearance rates (half-lives) of TCK and CK-MB. TCK was measured enzymatically, and the CK-MB isoenzyme was separated by agarose electrophoresis and quantitated by densitometry. The men's and women's post-race mean TCK levels were significantly elevated (P less than 0.05) above pre-race values at 24 h (3322 U . l-1, 946 U . l-1 and 48 h (1787 U . l-1, 508 U . l-1). In addition, CK-MB was significantly elevated both 24 h (5.1%, 3.3%) and 48 h (2.5%, 1.8%) post-race (P less than 0.05). The men's 24-h TCK was 22.3 times the pre-race value, while the women had an 8.6-fold increase in TCK. The mean 24-h post-race CK-MB activities were 166 U . l-1 for the men and 31 U . l-1 for the women. The mean increase in CK-MB activity was 41.5-fold for the men and 7.8-fold for the women. Furthermore, the men had a mean half-life (t1/2) of 30.4 h for TCK and 12.0 h for CK-MB; the women's t1/2's were 29.4 and 16.8 h, respectively. At all time points, the men evidenced significantly (P less than 0.05) higher TCK and CK-MB enzyme activities than did the women.(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗
PubMed1985

Variations in vitreous humor chemical values as a result of instrumentation.

Urea nitrogen, glucose, sodium, potassium, and chloride were measured in common vitreous humor samples using a variety of instruments. There was found to be variation in values obtained by the different procedures for each of these constituents. The variation in electrolyte values between the different procedures can pose real problems in attempting to determine the presence of an antemortem dehydration or low salt condition. Possible reasons for these variations are discussed, and the normal range of values of both sodium and chloride for the different instrumentalities is provided. However, variations in values for both urea nitrogen and glucose would not pose any problems of interpretation for forensic science evaluations.

Blood Glucose↗
PubMed1984

Chromatographic behavior of immunoglobulin-bound creatine kinase on DEAE-Sephadex A-50.

We investigated the chromatographic behavior of CK isoenzymes and immunoglobulin-bound macro-CK by discontinuous gradient elution from DEAE-Sephadex A-50 at pH 7 and 8. In four of five patients with macro-CK, the macro-CK was eluted with the MB buffer at pH 8, but a significant portion of the complex was eluted with the MM buffer at pH 7, in a region between CK-MM and CK-MB. In the fifth patient, the macro-CK was eluted with the MB buffer at both pH values. The immunoglobulin patterns of all five patients and of normal serum showed that IgG and IgM are eluted mainly with the MM and MB buffers, respectively, at both pH values, whereas IgA is eluted mainly with the MB buffer at pH 8, but at pH 7, shows a significant shift similar to that of macro-CK. These characteristic patterns allowed the identification of the immunoglobulin in macro-CK as IgA in the first four patients, and as IgM in the fifth patient.

Adult↗
PubMed1984

Comparison of serum creatine kinase and creatine kinase MB activities post marathon race versus post myocardial infarction.

Serial total creatine kinase (CK) and CK MB activities were determined in the serum of seven runners following a marathon race and compared to enzyme activities in the sera from five patients following acute myocardial infarction (AMI). In the runner's sera, total CK and CK MB activities were significantly elevated at 1, 24, 48 and 72 hours post marathon race when compared to the 1 hour pre-marathon samples (p less than 0.01). Serum CK MB activities peaked at 24 hours in both groups of subjects. The MB activities 24 hours following the marathon were substantially higher (91 +/- 30 U/l; mean +/- SD) than the MB activities 24 hours following AMI (46 +/- 38 U/l). However, the percentages of CK MB 24 hours following the marathon and AMI were almost identical (7.0 +/- 2.4% and 7.2 +/- 2.3%, respectively). Furthermore, CK and CK MB clearances were significantly prolonged (p less than 0.02 and p less than 0.001, respectively) following the marathon race (T 1/2 CK, 49 hours; T 1/2 CK MB, 29 hours) as compared to following AMI (T 1/2 CK, 27 hours; T 1/2 CK MB, 12 hours). These results suggest release of CK MB from the skeletal muscle of marathon runners. Therefore, we recommend that elevation of CK MB in the range indicative of myocardial damage be interpreted with caution in long-distance runners.

Adult↗
PubMed1984

Profile of creatine kinase isoenzymes in skeletal muscles of marathon runners.

The proportion of creatine kinase (CK; EC 2.7.3.2) isoenzyme MB activity was increased in skeletal muscle biopsies obtained from five long-distance runners, both 2 h before (mean 7.7%, SD 2.4%) and 30 min after (mean 7.2%, SD 1.2%) a marathon race, as compared with that in biopsies from five nonrunners (controls less than or equal to 1.0%). Further, mitochondrial CK and CK-BB isoenzymes were present in homogenates of the runners' skeletal muscle samples but not in those of the nonrunners. However, there were no substantial differences in the mean total CK activities per gram (wet wt.) of muscle tissue among premarathon samples, postmarathon samples, and nonrunners' samples (3148, 3365, and 3049 U/g, respectively). We conclude that the metabolically active gastrocnemius muscle of long-distance runners is qualitatively similar to the heart muscle in its CK isoenzyme composition.

Adult↗
PubMed1983

Serum enzyme changes during marathon training.

Blood enzyme activities that might be suggestive of organ-specific damage were measured over a six-week period in two, male, long-distance runners training for a marathon. Striking changes were observed in the CK and LD isoenzymes. Runner B exhibited a flipped LD1/LD2 isoenzyme ratio that paralleled his persistent MB CK elevation. The hepatic enzyme ALT was transiently elevated in Runner A. These data suggest that increases of cardiac isoenzymes (MB CK and LD1) and the specific hepatic enzyme ALT could lead to an inappropriate laboratory diagnosis of a myocardial infarction or liver disease, respectively, in a healthy runner during intense training for a marathon.

Adult↗
PubMed1982

Sodium measurements in multiple myeloma: two techniques compared.

Sodium was determined by flame photometry and by direct potentiometry in 56 serum or plasma samples from 24 patients with multiple myeloma or macroglobulinemia. We observed differences between the two techniques as large as 17 mmol/L (12%). The flame-photometric values decreased relative to the direct-potentiometric values as protein increased or water content decreased. Moreover, the two sodium measurements could not be interconverted simply on the basis of correcting for protein or water content. There was significantly lower residual variance (p less than 0.005) when the direct-potentiometric sodium values were compared with the osmolality (corrected for the influence of glucose and urea nitrogen) than when the flame-photometric values for sodium were so compared. We conclude that direct potentiometric measurements of sodium in patients with multiple myeloma gives clinically relevant results but flame photometry does not. Clearly, the method by which sodium is measured in patients with multiple myeloma must be considered if results are to be interpreted correctly.

False Negative Reactions↗