Biomedical subjects

K Kotaska

Publications and source records attributed to K Kotaska.

9 recordsLinked to original sources

PubMed2004

[Evaluation of three dosage regimens of amikacin using pharmacokinetic models in patients with cystic fibrosis].

BACKGROUND: Once-daily administration of aminoglykosides is routinely used, but comparative efficacy data for patients with cystic fibrosis are not available. METHODS AND RESULTS: The aim of the this study was to compare the predicted pharmacodynamic (PD) activity of amikacin at 28 mg/kg/den administered every 24 hod.(q24h), q12h, and q8h. Pharmacokinetic (PK) data were derived from analysis of the amikacin serum concentration from 42 CF children patients. Individual pharmacokinetics values were used to construct serum concentration--versus time curves and to determine various indices (c peak/MIC ratio and time during the concentration was less than the MIC--T < MIC) for all three dose regimens described above. MIC (minimal inhibitory concentration) for Pseudomonas aeruginosa was 4 mg/l. Significantly lower c peak/MIC but shorter T < MIC were noted when regimens of q8h versus q12h (p < 0.001), q8h vs. q24h (p < 0.001) and q12h vs. q24h (p < 0.001) were compared. This analysis suggests that the potential advantage of achieving a greater c peak/MIC with once-daily aminoglycoside administration may be neutralized by the significantly greater T < MIC in CF patients compared with that achieved with multiple-daily-dosing regimens. CONCLUSIONS: Routine use of once daily amikacin administration could not be recommended until the clinical data confirming efficiency of this dose modality are available.

Adolescent↗

PubMed2004

[Ghrelin--structure, function and clinical applications].

Ghrelin is a peptidic hormone composed of 28 aminoacid residues. It is produced by enteroendocrine cells of stomach and intestine. It is also produced in pancreas, kidney, placental tissue, thyroid gland, hypothalamus, and hypophysis. Gastrectomy leads to 65-80% decrease of plasma levels of ghrelin. In human organism, ghrelin stimulates secretion of growth hormone, prolactin, and ACTH. Ghrelin also has orexigenic activity (increases food intake), influences the sleep/wake cycle, gastric motility and secretion, cardiovascular functions, regulates endocrine function of pancreas and metabolism of glucose and shows an antiproliferative effect. Ghrelin is an important regulatory part of the homeostasis of the organism, and iterconnects neuroendocrine and metabolic response of the organism to starvation, and it is considered as a counterpart to leptin. Ghrelin was discovered by Japanese scientists in 1999 as a natural ligand of an "orphan" receptor GHS1a, which is specific for a group of synthetic peptides (growth hormone secretagogues--GHS) stimulating secretion of growth hormone. Plasma levels of ghrelin reflect short-time changes of food intake, as well as long-time changes of the nutritional state of the organism. Plasma levels of ghrelin are decreased after food intake and in obese humans, and they are increased during starvation and in patients with mental anorexia. Plasma levels of ghrelin in humans correlate negatively with body mass index, amount of body fat, size of adipocytes, and plasma levels of insulin, glucose, and leptin. Thus, ghrelin probably plays a role as a metabolic signal of hunger.

Energy Metabolism↗

PubMed2003

Inhibin B, follicle stimulating hormone, luteinizing hormone and testosterone during childhood and puberty in males: changes in serum concentrations in relation to age and stage of puberty.

Inhibin B is a gonadal dimeric polypeptide hormone that regulates synthesis and secretion of follicle stimulating hormone (FSH) in a negative feedback loop. The aim of the present study was to determine changes in serum inhibin B, gonadotropins and testosterone concentrations during childhood and puberty in males. We studied the relationship between circulating inhibin B, gonadotropins and testosterone in serum of healthy boys during the first two years of life and then in pubertal development. Using a recently developed two-side enzyme-linked immunosorbent assay (ELISA), inhibin B levels were measured in the serum of 78 healthy boys divided into eleven age groups from birth to the end of pubertal development. In addition, serum levels of gonadotropins and testosterone were measured. Serum inhibin B, gonadotropins and testosterone increased during the first months of postnatal life. A peak in serum inhibin B and gonadotropins concentrations was observed around 3-4 months of age. There was a significant positive correlation between serum inhibin B and gonadotropins and testosterone levels during the first 2 years of life. After this early increase, serum inhibin B, gonadotropins and testosterone levels decreased significantly and remained low until puberty followed by an increase beginning with the onset of puberty. Serum levels of inhibin B reached a peak at stage G3 of puberty. Around midpuberty, inhibin B lost its positive correlation with luteinizing hormone (LH) and testosterone from early puberty, and developed a strong negative correlation with FSH, which persisted into adulthood. We conclude that inhibin B plays a key role in the regulation of the hypothalamic-pituitary-gonadal hormonal axis during male childhood and pubertal development. Inhibin B is a direct marker of the presence and function of Sertoli cells and appears to reflect testicular function in boys.

Aging↗

PubMed2003

Inhibin B, follicle stimulating hormone, luteinizing hormone, and estradiol and their relationship to the regulation of follicle development in girls during childhood and puberty.

Inhibin B, produced by granulosa cells in the ovary, is a heterodimeric glycoprotein suppressing synthesis and secretion of the follicle stimulating hormone (FSH). The aim of the present study was to determine hormone profiles of inhibin B, FSH, luteinizing hormone (LH), and estradiol in girls during childhood and puberty and to evaluate whether inhibin B is a marker of follicle development. We examined the correlation between inhibin B and gonadotropins and estradiol during the first two years and across the pubertal development. Using a specific two-side enzyme-linked immunosorbent assay (ELISA), inhibin B levels were measured in the serum of 53 healthy girls divided into 8 groups according to age. In addition, serum FSH, LH, and estradiol were measured by chemiluminescent immunoassay in all serum samples. A rise in serum levels of inhibin B (55.2+/-7.3 ng/l, mean +/- S.E.M.) and FSH (1.78+/-0.26 UI/l), concomitant with a moderate increment of serum LH (0.36+/-0.09 UI/l) and estradiol (45.8+/-12.2 pmol/l) concentrations was observed during the first three months of life and declined to prepubertal concentrations thereafter. A strong positive correlation between inhibin B and FSH (r = 0.48, p<0.05), LH (r = 0.68, p<0.001) and estradiol (r = 0.59, p<0.01) was demonstrated during the first 2 years of life. A rise in serum levels of inhibin B, FSH, LH, and estradiol was found throughout puberty. Inhibin B had a strong positive correlation with FSH (stage I of puberty: r = 0.64, p<0.05; stage II of puberty: r = 0.86, p<0.01), LH (I: r = 0.61, p<0.05; II: r = 0.67, p<0.05), and estradiol (II: r = 0.62, p<0.05) in early puberty. From pubertal stage II, inhibin B lost this relationship to gonadotropins and estradiol. Serum inhibin B and FSH levels increased significantly during pubertal development, with the highest peak found in stage III of puberty (133.5+/-14.3 ng/l), and decreased thereafter. In conclusion, inhibin B is produced in a specific pattern in response to gonadotropin stimulation and plays an important role in the regulation of the hypothalamic-pituitary-gonadal axis during childhood and puberty in girls. Inhibin B is involved in regulatory functions in developing follicles and seems to be a sensitive marker of ovarian follicle development.

Adolescent↗

PubMed2003

Serum alpha-glutathione S-transferase as a sensitive marker of hepatocellular damage in patients with cystic fibrosis.

The aim of the study was to evaluate serum a-glutathione S-transferase (s-GSTA) levels in patients with cystic fibrosis (CF) and to compare s-GSTA with other liver function tests and with a hepatic ultrasound scan (US). The cytosolic enzyme, alpha-glutathione S-transferase is predominantly found in the liver and is distributed uniformly in the liver tissue. In our study s-GSTA levels were measured in 37 CF patients aged 1 to 28 years (mean age 10.4 years, 24 males). The control group consisted of 27 patients aged 2 to 17 years (mean age 8.5 years, 18 males). The presence of hepatobiliary abnormalities was assessed by clinical examination, ultrasound scan, s-GSTA, and conventional liver enzymes: alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST) and gama-glutamyl transferase (GMT). The calculated 5-95 % range of s-GSTA for the control group was 0.098-2.54 microg/l, for the CF group 0.43-9.76 microg/l. Mean s-GSTA level in the control group was 1.55 microg/l (S.D.=1.57), and 2.05 micro/l (S.D.=2.60) in the CF group. In the group of CF patients, the serum levels were significantly higher than in the control group (P<0.01). No significant correlation existed in the CF group between s-GSTA and conventional liver tests (ALT, AST, ALP and GMT). Four patients in the CF group had hepatobiliary abnormalities detectable by conventional liver tests, s-GSTA and US. Four patients had abnormal s-GSTA, while conventional liver tests and US were normal. One other patient had abnormal hepatic US, but normal standard liver tests and s-GSTA. The study has suggested that a raised s-GSTA level might be a marker of possible pathological changes of the hepatobiliar system in CF patients. Serum GSTA seems to be a more sensitive marker than transaminases for the monitoring of hepatocellular integrity and as an early predictor of hepatic damage.

Adolescent↗

PubMed2003

Common CYP21 gene mutations in Czech patients and statistical analysis of worldwide mutation distribution.

CYP21 gene molecular analysis was performed to determine the mutational analysis of 87 unrelated Czech patients with different forms of steroid 21-hydroxylase deficiency. Eight of the most common point mutations (intron 2 splice, P30L, 8 bp deletion in exon 3, I172N, V281L, Q318X, R356W, P453S) were analyzed using Amplification-created restriction site method. Cluster in exon 6 mutation was analyzed using allele-specific oligonucleotide hybridisation. Deletions and conversions were screened by modification of an sequence specific oligonucleotides hybridisation. The most frequent mutation in Czech patients was intron 2 splice mutation (45.4%). The comparison of mutation frequencies was made among Czech and European population (high frequency of intron 2 splice, 8bp deletion, P30L, P453S and low frequency of deletions/conversions in Czech population) and among Czech and different regions worldwide (low frequency of deletions/large gene conversions, V281L, R356W, high frequency of intron2, 8bp deletion, P30L and P453S in Czech population). We compared common mutation frequencies of different regions worldwide (North and South America, Asia, North Africa, Europe). Significant differencies in selected regions were determined by ANOVA statistical analysis (One-sample t-test, confidence interval) at value of p<0.05.

Adolescent↗

PubMed2002

Insulin-like growth factor binding protein-3 in patients with liver cirrhosis.

Aim of the study was to evaluate serum levels of insulin-like growth factor binding protein-3 in patients with liver cirrhosis and to compare serum IGFBP-3 levels with other liver function tests. Fifty-one patients with liver cirrhosis were selected for our study. We measured IGFBP-3 (1.67+/-1.06 mg/l, mean+/-SD), albumin (32+/-8 g/l), prealbumin (0.22+/-0.14 g/l), AST (2.29+/-2.38 microkat/l), ALT (2.11+/-4.83 microkat/l) and cholinesterase (mean 78.6+/-45.2 microkat/l) in the serum. There was a significant positive correlation of serum IGFBP-3 with serum albumin and serum cholinesterase. The correlation coefficient was much lower between serum IGFBP-3 and serum prealbumin. There was no significant correlation between serum AST, ALT and IGFBP-3. Serum IGFBP-3 proves to be a better marker for the hepatic synthetic capacity than serum albumin or cholinesterase.

Adult↗

PubMed2002

[Amylin--its physiological role in humans].

Amylin is a polypeptide hormone composed of 37 aminoacids, that is produced in pancreatic beta-cells, and that was discovered in 1987. Releasing amylin into the circulation is increased postprandially, proportionally to the amount of digested food. Daily profile of amylin plasma levels corresponds to the profile of insulin. Normal plasma levels of amylin vary from 4 pmol/L (fasting) to 25 pmol/L (postprandially). Receptors for amylin are highly concentrated especially in the central nervous system--area postrema and nucleus accumbens. There is a 20% sequence homology between amylin, calcitonin and adrenomedullin and 44% homology with calcitonin gene--related peptide. Amylin contributes to the regulation of postprandial glycaemia by suppression of glucagon release and by regulation of gastric emptying. Deficit os amylin is typical for diabetes mellitus type 1 or for the late stage of diabetes type 2. Insulin resistance in obese patients is characterized by increased levels of both insulin and amylin. Amylin decreases food intake and participates in the regulation of body weight. Some biochemical forms of amylin cause proliferation of osteoblasts and inhibit bone resorption. Amylin modulates insulin sensitivity of skeletal muscle, contributes to the regulation of blood pressure and causes vasodilatation.

Amyloid↗

PubMed1999

[Orexins and orexin receptors].

The hypothalamus plays a central role in the integrated control of feeding and energy homeostasis. Two novel neuropeptides Orexin -A and -B were identified. Orexins activate two closely related G protein-coupled receptors and stimulate food consumption. They act also as mediators in the central feedback mechanism and regulates feeding behavior.

Animals↗