Biomedical subjects

V Vitek

Publications and source records attributed to V Vitek.

28 records · Page 2Linked to original sources

PubMed1977

Enzyme activities in quadriceps femoris muscle of obese diabetic male patients.

In biopsy samples of the lateral part of the quadriceps femoris muscle of 6 obese diabetic male patients and of 11 obese males with a normal glucose tolerance, the activities of 7 enzymes of energy metabolism were estimated: hexokinase, cytoplasmic glycerol-3-phosphate: NAD dehydrogenase, triosephosphate dehydrogenase, lactate dehydrogenase, citrate synthase, malate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase. The obese diabetic male patients exhibited decreased activities of enzymes of carbohydrate breakdown and cytoplasmic NAD regeneration. Enzymes connected functionally with aerobic metabolism were less affected. The unchanged activity of 3-hydroxyacyl-CoA dehydrogenase points to an increased role of fatty acid catabolism in the muscle.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1976

The effect of severe trauma on urinary cyclic AMP in children of different ages.

Under routine clinical conditions the urinary excretion of cyclic AMP was studied in 97 healthy children (3 months to 16 years old) and 65 child victims of various forms of trauma and proved to be age-dependent. The mean admission cAMP urinry levels for children of all ages were increased by 44.8% and were time dependent. In 26 injured children (3 months to 9.5 years old) the excretion increased to 12.10 +/-1.29 mumol cAMP/g creatinine as compared to 8.06 +/- 2.25 mumol cAMP/g crEAtinine (50.0%; P less than 0.01) and in 38 children (9.5-16 years) it rose to 6.43 +/- 4.12 from 4.72 mumol +/- 1.10 (36.2%; P less than 0.001). In 23 victims admitted within the first two hours after trauma the cAMP levels were elevated by 31.25% in contrast to 49.2% elevation in those admitted from 2 to 24 h after trauma. In a five-day follow-up of a group of 15 surviving patients the highest excretion of cAMP was found on the first day. It was followed by a steep decline until the values plateaued on the third day at values slightly elevated above control. Compared with the fifth day, the first day excretion expressed as mumol cAMP/24 h was enhanced by 92.3% (P less than 0.01) and as a ratio to creatinine (muol/g creatine) by 52.24% (P less than 0.05. In comparison with injured adults studied previously under analogical conditions, the cAMP excretory response to trauma in children differs in higher intensity (P less than 0.01) and in the nature of the daily pattern starting with the third day. It is pointed out that the intensity of the cAMP response to pathological stimuli may be age-dependent also in other clinical conditions.

Adolescent↗

PubMed1976

Urinary excretion of cyclic adenosine 3',5'-monophosphate in children of different ages.

The urinary excretion of cyclic AMP was investigated in 97 healthy children, 3 months to 16 years old. When the excretion was expressed as mumol/24 h an increase with age (r = 0.693, P less than 0.001) and an increase with body weight (r = 0.700, P less than 0.001) were found to be quite similar. In relation to surface area, the average excretion for children up to 91/2 years old was 4.45 +/- 1.71 mumol/m2 in constrast with 2.22 +/- 0.66 mumol/m2 in older children (P less than 0.001). The decline appears to be associated with approaching puberty. When cAMP excretion was related to urinary creatinine, an inverse correlation with age was found (r = -0.772, P less than 0.001). In the youngest category, 3 months to 4 years old, the ratio was 9.26 +/- 1.49 mumol/g creatinine vs 4.67 +/- 1.05 mumol/g creatinine in the age group 12 to 16 years old (P less than 0.001), which compares closely with the normal adult average of 4.34 +/- 1.25 mumol/g creatinine found in our previous study. Throughout there was no evidence of sex differentiation.

Adolescent↗

PubMed1976

Time related response of urinary cyclic adenosine monophosphate to trauma.

Urinary cyclic adenosine monophosphate levels were measured in 150 patients with accidental injury of varying causes. Thirty-eight healthy adults of both sexes serving as controls excreted 2.21 to 6.85 micromoles of cyclic adenosine monomphosphate per gram of creatinine, mean 4.34 +/- 1.25. In 120 patients with trauma on admission, the excretion was increased by 15.7 per cent, p less than 0.05, and the changes showed a time related pattern. In patients admitted within the first 30, 60 and 120 minutes after trauma, the mean excretion was changed by 19, 10 and minus 2.8 per cent, respectively, and in those admitted between two and 24 hours by 30 per cent. Twelve patients with differing types of trauma showed a mean 24 hour excretion reaching its peak on the first day, 44 per cent, and declining to its nadir of 2.25 micromoles per gram of creatinine on the third day, minus 47 per cent, p less than 0.01. A second rise reached its peak on the fifth day, p less than 0.05. Thereafter, the excretion fluctuated widely with peaks significantly above and below the control range, and we were unable to correlate these changes with any specific factors. In post-traumatic acute renal failure, the nucleotide excretion fell within several hours and usually reached low values, that is, below 0.25 micromoles per 1,000 milliliters per 24 hours within one to three days. In general, the excretory pattern for cyclic adenosine monophosphate followed that of creatinine clearance, but in the diuretic phase of the recovering kidney, the cyclic adenosine monophosphate levels remained more depressed than those of creatinine. The high sensitivity of urinary cyclic adenosine monophosphate to abnormalities in renal function suggests its potential as a clinical indicator.

Acute Kidney Injury↗

PubMed1975

Lactosuria - a new metabolic feature of severe cerebrocranial trauma.

Under controlled dietary conditions the urinary excretion of lactose was studied in 15 healthy persons, 15 patients with cerebrocranial trauma and 15 patients with extracranial trauma. Urinary lactose levels were found to be markedly increased in patients with head injury and ranged from 10.3 to 147.7 mg/24 h with a mean 63.4 mg/24 h in contrast to patients with other injuries (3.1 to 17.0 mg/24 h, mean 9.4 mg/24 h; P less than 0.001), and healthy individuals (3.3 to 17.93 mg/24 h, mean 7.6 mg/24h; P less than 0.001). In the head injury group the lowest values were found in drowsy or disoriented patients with cerebral concussion and the highest in comatose subjects. The level of lactosuria decreases after approximately 12 to 16 days to normal levels even when the patient remains unconscious. An earlier return to normal excretion parallels or preceeds the reappearance of consciousness. Unlike alimentary lactosuria, caused by ingestion of milk or other dairy products in large quantities, the elevated lactose levels in head injury patients were not usually accompanied by a comparable rise in galactose excretion, mean 11.45 mg/24 h versus 9.17 mg/24 h in controls; P less than 0.2. The mechanism of enhanced lactose excretion in severe cerebrocranial trauma remains unknown. It is suggested that it may be associated with either an increased catabolism of brain gangliosides or a stimulated lactose synthesis in peripheral tissues probably due to the participation of the lactogenic hormone prolactin.

Adolescent↗

PubMed1975

M. Quadriceps femoris of man, a muscle with an unusual enzyme activity pattern of energy supplying metabolism in mammals.

1. The following enzyme activities were estimated in needle-biopsy samples of the lateral part of the human quadriceps femoris muscle: triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), NAD : glycerol-3-phosphate dehydrogenase (GPDH), hexokinase (HK), NAD: malate dehydrogenase (MDH), citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase. 2. Although the enzyme activities in muscles of women were lesser than in those of men, no difference was found in the calculated enzyme activity ratios. There is thus no sex-dependent metabolic type-differentiation in this muscle. 3. The human quadriceps femoris is a low-activity muscle, in comparison with muscles of homoiotherm laboratory animals. The enzyme activity ratio of TPDH to CS, characterizing the glycolytic pyruvate formation to aerobic oxidative capacities, shows this muscle to be of an intermediate type in this respect, similarly as the extensor digitorum longus of the rat. The relatively very high capacity of glucose phosphorylation (HK), the high aerobic regeneration of cytoplasmic dehydrogenated NAD (GPDH) and the very low anaerobic regeneration (LDH), show the unusually high proportion of carbohydrates (glucose) which can be broken down aerobically.

Acetyl Coenzyme A↗

PubMed1971