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Biomedical subjects

J Sonka

Publications and source records attributed to J Sonka.

At least 37 records · Page 2Linked to original sources
PubMed1990

[A low-energy protein diet and complete fasting in obese patients. Effect on energy metabolism].

The authors investigated 38 obese patients with a BMI above 35. The patients were divided into four groups. The first three groups were on a strict reducing diet, which differed as to the energy values (1.38 MJ to 2.75 MJ) and the amount of protein (5.58 g N to 17.91 g N) per 24 hours. The fourth group fasted. In the course of 16 days metabolic balances were made and the energy output at rest was assessed by indirect calorimetry. In all groups the body weight declined markedly on average by 8.2 to 10.5 kg. The energy consumption at rest declined only during the complete fast. The fasting patients were in a negative nitrogen balance. The nitrogen balance was positive in the patients who were given 11.2 g N and 17.91 g N/24 hours. In all groups the fat utilization increased and the sugar utilization declined. The protein catabolism declined markedly only in the fasting patients. It may be summarized that the low-energy protein diet is, as compared with the fast, a more physiological way to achieve weight reduction, in particular because despite weight reduction a positive nitrogen balance is achieved.

Adult↗
PubMed1990

Low-energy protein diet and starvation diet in the obese--effect on energy metabolism.

38 obese patients with BMI in excess of 35 were monitored, the patients were divided into four groups. The first three were on a strict slimming diet which different as to the energy values (1.38 MJ--2.75 MJ) and the amount of protein (5.58 g N--17.91 g N) per 24 hours. The fourth group was on a starvation diet. Metabolic balance values and resting energy cut put were measured by indirect calorimetry during 16 days of monitoring. In all groups the body weight declined markedly by an average of 8.2-10.5 kg. Resting energy consumption dropped only during absolute fasting. The starvation diet patients exhibited a negative nitrogen balance. Positive nitrogen balance was found in groups on 11.2 g N and 17.91 g N/24 hours. Fat utilization increased and sugar utilization declined in all groups. Protein catabolism declined markedly only in the fasting patients. Summed up, the low-energy protein diet is--in comparison with absolute diet--a more physiological way to achieving weight reduction, in particular, because, despite the loss of weight, a positive weight balance is achieved, too.

Adult↗
PubMed1990

[Sexual development in obese women].

By means of an interview and the questionnaire "Heterosexual Development of Women" [HDW] the authors subjected to sexuological examination 129 obese women aged 20-50 years with a body mass index above 25. As regards the time when overweight developed 29 women developed obesity during the prepubertal period and in 100 of the women obesity developed during adolescence and later. It was revealed that the sexual development of obese women was normal. The mean values in the HDW questionnaire in both subgroups with a different period of development of overweight were all within the normal range.

Adult↗
PubMed1990

[Factors affecting normal levels of insulin, cortisol, STH, thyroxine and triiodothyronine].

Published "normal" values of some hormones have an excessively wide range and unequal mean values because the material on which these values are based is from subjects suffering from different diseases which only apparently are not associated with the investigated hormone, or else the specimens are obtained under non-standard conditions (malnutrition, stress, alcohol etc.). This wide range of normal values may hide incipient pathological processes and is not suitable even as control group. The investigation is based on the assessment of insulin, growth hormone (GH), cortisol, thyroxine (T4) and triiodothyronine (T3) in a group of blood donors. The assembled results were compared with two other groups of blood donors and a group of obese subjects. The following findings were assembled: We recommend to lower the upper borderline of "normal" insulinaemia from the recommended value of 26 to 20 i.u./l, as the original range may comprise milder forms of hyperinsulinism which is recently assumed to participate in the genesis of type 2 diabetes, hypertension, coronary ischemia and polycystic ovaries. Elevated normal values of serum insulin may be obtained also from blood donors who usually have breakfast before the blood is collected. The wide range of cortisolaemia is due to the diurnal rhythm. The basal value is raised by a declining blood sugar level, alcohol, obesity and of course, varying forms of stress. The upper range of cortisolaemia at 8 a.m. should not be beyond the range of 140-690 nmol/l. GH secretion is governed by an individual 3.5-hour cycle as well as changes of the blood sugar level, e. g. during the OGTT: the declining blood sugar level raises the GH level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Sexual development and life of obese women].

The authors examined by means of a structured interview and four questionnaires (heterosexual development of women, sexual activity of women, sexual function of women and N5 assessing the incidence and intensity of neurotic symptoms 100 obese women, mostly aged 21-40 years, who had a regular sex life. 73 of them had BMI values of 22 to 30. In the remaining 27 morbid obesity was involved with BMI values above 30. In the group as a whole the course of sexual development and life did not differ markedly from that of average women. A retarding trend with lower values in questionnaires on sexual activity and sexual function was found in women with primary and morbid obesity. In these sub-groups the number and intensity of neurotic symptoms was elevated. Their intensity in the group as a whole was significantly higher than in the ordinary population.

Adult↗
PubMed1989

[Dehydroepiandrosterone. Renaissance after 13 years].

DHEA, a steroid precursor of androgens and estrogens has also an inhibitory effect on several enzymes, namely on 11 beta-hydroxylase, NADH oxidase and glucose 6-phosphate dehydrogenase. The latter is the rate limiting enzyme of the pentose phosphate cycle. This metabolic pathway provides the cells with extramitochondrial NADPH and pentose phosphates. NADPH is used for the synthesis of fatty acids and steroids. Together with ribose 5-phosphate, NADPH (as coenzyme of folate reductases) is required for the synthesis of nucleic acids. A deficient production of DHEA has been found to be responsible for several diseases obesity, diabetes type 2, hypertension, arteriosclerosis and hyperuricemia as well as malignant growth (low DHEA syndrome). DHEA administration favourably modified several of these metabolic disorders. These studies were started in our laboratory in 1962 and stopped in 1976 because we were short of DHEA. At that time the response to our results was rather theoretical, but the last years a new wave of interest in DHEA called for two consecutive symposia, where important findings were presented (Paris in January and Jena in April 1989). It is a damage that this new trend, started in our laboratory, could not be pursued up to now without interruption.

Animals↗
PubMed1989

Phosphorylation by cell surface protein kinase of bovine and human fibrinogen and fibrin.

Human and bovine fibrinogen as well as fibrin are shown to be phosphorylated by Co631 (monolayer, hamster) and RPL12 (suspension, chicken) cells by their surface protein kinase of the casein kinase II type. The phosphate label is introduced into the alpha-peptide. The kinase system phosphorylates serine residues and utilizes GTP equally well as ATP. The participation of intact cell surfaces indicates the possibility of phosphorylation of extracellular fibrinogen independently of the site of its biosynthesis.

Animals↗
PubMed1989

Evidence for ecto-protein kinase activity that phosphorylates Kemptide in a cyclic AMP-dependent mode.

The heptapeptide Leu-Arg-Arg-Ala-Ser-Leu-Gly (Kemptide) is a synthetic construct of a substrate for cAMP-dependent protein kinase (PK). In this work we show that Kemptide has all the properties of a cytophilic substrate, i.e. it is a molecule preserving cell membrane intactness when added to cultured cells. Kemptide thus satisfies the prerequisites for employment in assays for cell surface-located ecto-PK activity. Different types of intact cells catalyze the phosphorylation of Kemptide in the presence of extracellular ATP and cAMP with Km values of 3-4 microM for Kemptide. Kemptide phosphorylation was influenced by PKI, the inhibitory protein specific for cAMP-PK. The results of comparative experiments with intact cells and with cell extracts demonstrate the ectoenzyme nature of this cAMP-PK. Further, the possibility was ruled out of a transfer of enzyme activity from damaged cells to the surface of intact cells. The anchorage of the surface cAMP-PK activity to the plasma membrane appears to be relatively stable since (i) cell supernatants, obtained after preincubation of intact cells with cAMP or Kemptide, did not show Kemptide phosphorylation, and (ii) the cAMP-dependent PK activity remained with cells even after five consecutive washes with cAMP or Kemptide. This is in contrast to the ecto-cAMP-independent phosvitin/casein type PK (Kübler, D., Pyerin, W., Burow, E., and Kinzel, V. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 4021-4025) which is released from intact cells through the addition of substrate. Data are presented which show that both ectokinase activities are exhibited independently. In conjunction with published evidence for an active export of cAMP from cells as well as for the appearance of extracellular ATP the demonstration of an ecto-cAMP-PK further supports the potential of PK for intercellular regulation. The potential of ecto-cAMP-PK is demonstrated by its ability to phosphorylate biologically active forms of atrial natriuretic peptide, the atrial natriuretic peptide, which possesses the specific sequence for a cAMP-PK-catalyzed phosphorylation.

Amino Acid Sequence↗
PubMed1989

[The effect of a short-term reducing regimen on hormonal secretion in obese patients].

A twelve-day reducing regime involving exercise and a reducing diet (2.5 MJ/day), led in 23 obese women to an average loss of body weight of 4.52 +/- 0.35 kg. The loss of adipose tissue during the reducing regime was greater than the total loss of body weight, obviously due to proliferation of lean body mass as a result of exercise. Concurrently a significant decline of the mean morning concentration of thyroxine, triiodothyronine, C-peptide and STH in serum was recorded, while the concentration of TSH, cortisol, prolactin, LH and FSH increased insignificantly and the concentration of insulin and testosterone declined insignificantly. Exercise thus did not prevent a decline of triiodothyronine induced by the low energy diet. The exercise in the morning did not cause a stress conditioned increase of the secretion of cortisol, prolactin and STH at the onset and at the end of the reducing regime. From the metabolic aspect the favourable absence of the stimulating action of exercise on cortisol secretion is due to the character of motor activity (40-50% VO2max). The absence of a stress conditioned rise of prolactin during exercise prevents the inhibiting action of prolactin on gonadal functions. The reducing regime has also a favourable effect on insulin secretion, as on the 12th day of the reducing regime there was a significant decline of the serum level of immunoreactive insulin in the course of exercise.

Adult↗
PubMed1989

[The effect of a low-energy protein diet in short-term ambulatory treatment of obese women].

Fourteen obese women (BMI 37.2 +/- 7.3) were treated with a very low energy diet containing 1555 kJ (370 kcal) for 14 days. Weight loss occurred in all cases (4.2-10.7 kg, mean 6.46 +/- 1.68 kg), although usual weight-reducing regimens have not succeeded before. There were no complications and results of usual biochemical tests did not change. Body mass index and concentrations of serum total cholesterol decreased significantly, insulin levels fell in the first and fourth hour of a glucose tolerance test. Also serum triiodothyronine concentrations declined significantly but not below the lower limit of normal results. We concluded that short-term very low energy diet treatment enable a safe decline of excessive body mass in out-patients, including those resistant to usual reducing diets.

Adult↗
PubMed1989

Initial and early effects of adriamycin in murine sarcoma 180 cannot be restored in a resistant subline by increasing the uptake and external concentration of the drug.

We demonstrate the early effects (1 day) of Adriamycin (ADM) on proliferation-stimulated and quiescent sensitive, and ADM-resistant cells of the murine tumor sarcoma 180 (S 180). By investigating cell-cycle distribution and thymidine labeling, it can be shown that sensitive cells are strongly affected by the drug, even in a proliferationarrested state. A remarkable but slow DNA synthesis is the prominent effect of this drug treatment on sensitive cells, even under nonstimulating conditions. In resistant cells, neither an increase in concentration nor a variation in drug uptake can induce effects that could be compared with those observed in the sensitive line. From these results we conclude that the early effects of ADM are not modulated by drug uptake.

Animals↗
PubMed1988

New trends in obesitology.

Several new problems in obesitology were pointed out in this book and commented with respect to experiments and experiences of our working group. The problem of the low triiodothyronine (T3) syndrome was treated in chapter 2. The decrease of serum T3 and increase of serum reverse T3 in obese subjects was induced by several factors, namely by fasting. A resistance to administered thyroxine and triiodothyronine was observed in these patients. This energy saving mechanism is at variance with slimming regimens. The prevention and treatment of this awkward complication was discussed. The next chapter (3) is concerned with the hormonal and metabolic effects of diet and motor activity in the course of slimming regimens. The different effects of diet and motor activity on epinephrine and norepinephrine in obese subjects were similar to those obtained by other investigators in nonobese humans. A great importance was attributed to an increased plasma level of cortisol in obese and nonobese subjects in the course of different forms of motor activity and related to a different intensity of exercise. Parallel to several of these experiments, beta-endorphin, thyroid hormones and glucagon were also estimated. It was suggested that motor activity for exercising subjects should not lead to an enhanced secretion of cortisol in view of the health deteriorating effects of increased cortisolemia and in view of an already stimulated secretion of this hormone in obese subjects on basal conditions. Vice versa, a decreased cortisolemia should be obtained in obese subjects treated with an appropriate motor activity and diet. It has been shown that diet without motor activity reduced the level of plasma androgens but in cooperation with motor activity, the level of androgens remained unaltered in the course of the reducing regimen. The conservation of a normal or even higher level of androgens is probably prerequisite for a positive nitrogen balance observed in the course of a combined slimming regimen, while diet without motor activity led in the studied conditions to a negative nitrogen balance. Chapter 4 was devoted to the role of motor activity in slimming regimens. In view of the metabolic effects of motor activity and the clinical late effects of obesity (osteoarthritis of the knees, hips and spine, arterial hypertension, overload of the cardiovascular system, diabetes mellitus etc.), a selection of motor activities was proposed. According to our long experience, we do not recommend jogging, running, jumping and all sports leading to collisions of players.(ABSTRACT TRUNCATED AT 400 WORDS)

Glucose↗
PubMed1987

Quantitative description of nuclear morphology in assessing resistance of sarcoma 180 to adriamycin.

Resistance to adriamycin generally is explained through changes of cell/drug interactions that possibly reflect structural alterations of intracellular targets. One of the main targets of adriamycin is believed to be nuclear chromatin. In order to recognize chromatin alterations, we studied cell nuclei morphology and chromatin structure by means of digital image analysis. The studies were performed in both adriamycin-sensitive and -resistant Sarcoma 180 cell lines which were cultured under growth-stimulated and nonstimulated conditions. Using specially developed methods, we extracted parameters characterizing geometrical, optical, and structural properties of the cell nuclei from light microscopical images. The latter parameters concerned microscopical appearances of condensed chromatin and were described by features of high-optical-density regions. The results demonstrated that the quantitative criteria applied enabled the discrimination of sensitive and resistant cells. The most important parameters are the nuclear size, number, distribution, and optical density of condensed chromatin regions. In addition, the criteria permit recognition of changes related to differences in the growth conditions of the cells. The data of the image analysis suggest that adriamycin resistance in Sarcoma 180 cells is associated with characteristic patterns of cell nuclear morphology which can be described with a sufficient number of appropriate parameters. The advantages of image analysis are evident when these results are compared with the flow cytometric findings. The conclusion is that structural features of nuclear chromatin provide information essential for the assessment of drug resistance.

Animals↗