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Biomedical subjects

J Vondrácek

Publications and source records attributed to J Vondrácek.

At least 19 recordsLinked to original sources
PubMed2004

[Psychological condition of children from pregnancies after assisted reproduction in the third year of life].

OBJECTIVE: To analyse psychological development of children born after assisted reproductive technology. DESIGN: Psychological analysis of the child's development related to the technology of assisted reproduction, length of pregnancy and multiple birth was performed and compared with the control group. SETTING: Institute for the Care of Mother and Child, Prague. METHODS: Out of the total number of 123 children born after assisted reproductive technology during the 1st half of the year 1998 in the Center ISCARE IVF, psychological development was evaluated in 109 children (88.6%). Ninety four children from this sample were assessed using mental, motor and behavior scales of the Bayley Scales of Infant Development II. RESULTS: Mental and motor development of infants born after intracytoplasmatic injection (ICSI) and after in-vitro-fertilisation (IVF) was not significantly different. Fullterm singletons born after assisted reproductive technology did not differ from control fullterm children. There was a developmental delay in both fullterm and preterm children from multiple pregnancies in comparison to control children. No child had serious impairment of psychic functions (developmental index <50). There were no significant differences in behavior records between children born after assisted reproductive technology and control children, but some parents had problems in educational care of their children born after assisted reproductive technology. CONCLUSION: From children born after assisted reproductive technology, those from multiple pregnancies may be at risk for later psychological development. The occurrence of educational problems in assisted reproductive families indicates a need of accessible professional care in this field.

Adult↗
PubMed2004

[Effect of early nutrition on growth parameters and psychomotor development of children of very low birth weight].

OBJECTIVE: The aim of the study was to evaluate influence of early nutrition on growth parameters and psychomotor development of children with very low birth weight (VLBW). DESIGN: A prospective clinical study. SETTING: Institute for Care of Mother and Child, Prague. METHODS: Thirty nine children of birth weight 1,000-1,499 were followed up to one year of their corrected age in a prospective study. The group was divided in two groups according to type of nutrition: 17 children (group A) were fed with milk of own mother - "preterm milk", 22 children (group B) were orally fed with mature milk from the Bank of mother milk - "term milk", which was fortified with BMF preparation (Nutricia, Netherlands). Both groups were comparable in basic anthropometric parameters (weight, lenght, circumference of head and thotax) and in psychosocial characteristics of their mothers. Growths parameters were monitored in weekly intervals for approximatelly eight weeks. In the period between 11th and 15th month of corrected age, the children were evaluated by a clinical psychologist on a blind basis in mental a motor development by using Bayley Scales of Infant Development (BSID-II). Statistical analysis was performed by chi-square test and t-test. RESULTS: No statistically significant differences between the two groups in evaluating the growth parameters were observed. The psychological examination demonstrated statistically significant differences in the motor development. The psychomotor developmental index (PVI) proved to be 84.4 +/- 14.6 in the group A and 94.3 +/- 12.5 in the group B (t-test = 2.28, p<0.05). There was not any statistically significent difference in metal development between the two groups. The mean mentel developmental index (MVI) was 98.2 +/- 10.2 in the A group and 101.0 +/- 13.3 in the group B. CONCLUSION: Result of the study indicate favorable effect of fortification of breast milk in VLBW newborns, especially in view of the observed favorable influence of fortfication on motor development of the children.

Breast Feeding↗
PubMed2001

Peri- and post-operative course of cytokines and the metabolic activity of neutrophils in human liver transplantation.

Peri- and post-operative (up to day 7 after surgery) neutrophil chemiluminescence and the plasma concentrations of interleukin 6 (IL-6), IL-8, IL-10 and tumour necrosis factor alpha (TNF-alpha) were evaluated in the blood of patients undergoing liver transplantation. IL-6, IL-8 and IL-10 levels increased during early reperfusion and then returned to normal mostly within the first post-operative day. TNF-alpha was increased during the whole period observed. Spontaneous as well as activated neutrophil chemiluminescence was depressed in early reperfusion and remained low during the whole period followed. Samples collected during early reperfusion provided positive correlation for IL-6 vs IL-8 as well as for IL-6 and IL-8 vs chemiluminescence. The data were also evaluated with respect to the outcome of transplantation. Since IL-8, IL-10 and TNF-alpha levels increased significantly during the first post-operative week, mainly in a group of patients who developed serious complications within the first month after surgery, we proved a connection between peri- and early post-operative induction of cytokine release and the outcome of liver allograft transplantation.

Adult↗
PubMed2001

Aryl hydrocarbon receptor-mediated activity of mutagenic polycyclic aromatic hydrocarbons determined using in vitro reporter gene assay.

Activation of aryl hydrocarbon receptor (AhR) by 30 polycyclic aromatic hydrocarbons (PAHs) was determined in the chemical-activated luciferase expression (CALUX) assay, using two exposure times (6 and 24h), in order to reflect the metabolization of PAHs. AhR-inducing potencies of PAHs were expressed as induction equivalency factors (IEFs) relative to benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In 24h exposure assay, the highest IEFs were found for benzo[k]fluoranthene, dibenzo[a,h]anthracene and dibenzo[a,k]fluoranthene (approximately three orders of magnitude lower than TCDD) followed by dibenzo[a,j]anthracene, benzo[j]fluoranthene, indeno[1,2,3-cd]pyrene, and naphtho[2,3-a]pyrene. The 6h exposure to PAHs led to a significantly higher AhR-mediated activity than the 24h exposure (generally by two orders of magnitude), probably due to the high rate of PAH metabolism. The strongest AhR inducers showed IEFs approaching that of TCDD. Several PAHs, including some strong mutagens, such as dibenzo[a,l]pyrene, cyclopenta[cd]pyrene, and benzo[a]perylene, elicited only partial agonist activity. Calculation of IEFs based on EC25 values and/or 6h exposure data is suggested as an alternative approach to estimation of toxic potencies of PAHs with high metabolic rates and/or the weak AhR agonists. The IEFs, together with the recently reported relative mutagenic potencies of PAHs [Mutat. Res. 371 (1996) 123; Mutat. Res. 446 (1999) 1] were combined with data on concentrations of PAHs in extracts of model environmental samples (river sediments) to calculate AhR-mediated induction equivalents and mutagenic equivalents. The highest AhR-mediated induction equivalents were found for benzo[k]fluoranthene and benzo[j]fluoranthene, followed by indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[a]pyrene, dibenzo[a,j]anthracene, chrysene, and benzo[b]fluoranthene. High mutagenic equivalents in the river sediments were found for benzo[a]pyrene, dibenzo[a,e]pyrene, and naphtho[2,3-a]pyrene and to a lesser extent also for benzo[a]anthracene, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[j]fluoranthene, dibenzo[a,e]fluoranthene and dibenzo[a,i]pyrene. These data illustrate that AhR-mediated activity of PAHs, including the highly mutagenic compounds, occurring in the environment but not routinely monitored, could significantly contribute to their adverse effects.

Animals↗
PubMed2001

Inhibitors of arachidonic acid metabolism potentiate tumour necrosis factor-alpha-induced apoptosis in HL-60 cells.

We investigated whether and how could various modulators of arachidonic acid metabolism affect apoptosis induced by tumour necrosis factor-alpha (TNF-alpha) in human myeloid leukaemia HL-60 cells. These included arachinonyltrifluoromethyl ketone (AACOCF3; cytosolic phospholipase A2 inhibitor), indomethacin (cyclooxygenase inhibitor), MK-886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2-dimethyl propanoic acid; 5-lipoxygenase-activating protein inhibitor), nordihydroguaiaretic acid (general lipoxygenase inhibitor), and arachidonic acid itself. Incubation of HL-60 cells with nordihydroguaiaretic acid resulted in apoptosis and it was characterised by mitochondria membrane depolarisation, release of cytochrome c from mitochondria into cytosol and activation of caspase-3. Indomethacin and nordihydroguaiaretic acid synergistically potentiated TNF-alpha-induced apoptosis, while arachidonic acid, AACOCF3 and MK-886 did not modulate its effects. Furthermore, indomethacin potentiated apoptosis in cells treated with a differentiating agent, all-trans retinoic acid, which induces resistance to TNF-alpha. However, the observed effects were probably not associated either with the cyclooxygenase- or lipoxygenase-dependent activities of indomethacin and nordihydroguaiaretic acid, respectively. Since indomethacin may reportedly activate peroxisome proliferator-activated receptors (PPARs), the effects of specific ligands of PPARs on apoptosis were studied as well. It was found that selective PPARs ligands had no effects on TNF-alpha-induced apoptosis. The findings suggest that arachidonic acid metabolism does not play a key role in regulation of apoptosis induced by TNF-alpha in the present model. Nevertheless, our data raise the possibility that indomethacin could potentially be used to improve the treatment of human myeloid leukaemia.

Apoptosis↗
PubMed2001

Modulation of death receptor-mediated apoptosis in differentiating human myeloid leukemia HL-60 cells.

Differentiating myeloid cells may become resistant to various apoptotic stimuli. In the present study, dimethyl sulfoxide (DMSO) and all-trans retinoic acid (ATRA) were found to modulate the sensitivity of HL-60 cells to death receptor-mediated apoptosis in a time-dependent manner. During the early stages of differentiation, DMSO treatment increased the response of HL-60 cells to tumor necrosis factor alpha; (TNF-alpha), but enhanced responsiveness was lost during later differentiation stages. In contrast, ATRA treatment induced resistance to TNF-alpha-induced apoptosis. HL-60 cells were resistant to Fas-mediated apoptosis but were sensitized by culturing in serum-free conditions. Similar to its effect on TNF-alpha sensitivity, DMSO pretreatment augmented the response to Fas-mediated signaling, which coincided with increased expression of Fas on DMSO-pretreated cells. However, during the later stages of DMSO-induced differentiation, sensitivity to anti-Fas antibody-induced apoptosis declined significantly, although Fas expression was still elevated. The reduced sensitivity to anti-Fas treatment partially correlated with increased Fas-associated phosphatase-1 mRNA expression. Thus, regardless of either Fas up-regulation or potentiation of TNF-alpha-mediated apoptosis during early DMSO-induced differentiation, a slow increase in resistance to apoptosis mediated through these death receptors occurs during DMSO-induced differentiation, which contrasts with the rapid induction of resistance following treatment with ATRA.

Antibodies, Monoclonal↗
PubMed2001

Monitoring river sediments contaminated predominantly with polyaromatic hydrocarbons by chemical and in vitro bioassay techniques.

Extracts of sediment samples collected from the Morava River and its tributaries (Czech Republic) were examined for mutagenic, dioxin-like, and estrogenic activities. Moreover, the human leukemic HL-60 cell line was tested as a potential model for the detection of effects of environmental contaminants on cell proliferation and differentiation processes. Analytical data indicate that the sediments were contaminated predominantly with polycyclic aromatic hydrocarbons (PAHs) and phthalate esters. The sums of concentrations of 16 U.S. Environmental Protection Agency priority PAHs ranged from 0.8 to 13.2 micrograms/g and those of phthalates reached up to 3,000 ng/g, while only low levels of chlorinated hydrocarbons were found. The main goal of the present study was to determine effects of PAH prevalence on in vitro bioassays, with special emphasis on dioxin-like activity. The dioxin-like activity was tested using a reporter gene assay based on chemical-activated luciferase expression (the CALUX assay). Significant dioxin-like activity (2.6-40.1 micrograms/g benzo[a]pyrene equivalents and 5.9-48.2 ng/g 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents) was detected in all samples, and the results obtained with various exposure times or with both crude and PAH-deprived extracts indicate that the response was probably caused almost exclusively by the presence of high concentrations of PAHs. This corresponds with results of chemical analyses and indicates that various exposure times would allow a discrimination between dioxin-like activities of persistent compounds and easily metabolized aryl hydrocarbon (Ah) receptor inducers. Only sediment extracts containing the highest concentrations of PAHs were mutagenic, as determined by the umu assay. Estrogenic activity was found in several samples (4.75-22.61 pg/g estradiol equivalents) using cells stably transfected with an estrogen-responsive element linked to a luciferase promoter. Noncytotoxic doses of extracts had no effects on HL-60 cell proliferation, while two of the tested crude extracts significantly enhanced their all-trans retinoic acid-induced differentiation. These activities were not associated with phthalate esters and/or PAHs. Our results indicate that cellular and biochemical in vitro assays based on various specific modes of action may yield data complementary to results of mutagenicity tests and that they could be useful in environmental risk assessment. High levels of PAHs are apparently associated with dioxin-like and mutagenic activities rather than with estrogenic activity.

Biological Assay↗
PubMed2000

[Regular respiration during sleep in children in the first months of life].

Regular respiration is an important parameter of quiet sleep in infants. At the earliest age, the periods of regular respiration are shorter as compared with the periods of EEG, EMG and EOG patterns of quiet sleep. The duration of periods with regular respiration significantly increases with age, and their coincidence with other parameters of quiet sleep becomes higher. The frequency of regular respiration significantly decreases with age. Very short periods of regular respiration, low coincidence with other parameters of quiet sleep, and very high frequency of regular respiration after the 12th week of life may indicate a delay in the central nervous system development.

Aging↗
PubMed1998

Total antioxidant capacity of serum increased in early but not late period after intestinal ischemia in rats.

The ischemia of small intestine was induced in anesthetized Wistar rats by occluding the superior mesenteric artery for 45 min and then the reperfusion was set. Serum samples were obtained at the end of the ischemic period and also during early (1 to 4 h) and late postischemic period (1 to 4 d). The total antioxidant capacity (TRAP) of serum samples was evaluated using luminol enhanced chemiluminescence. The increased mobilization of phagocytic cells and the release of reactive oxygen species into the circulation was observed from the first and second hour of the postischemic period, respectively. Nevertheless, the activity of natural antioxidant mechanisms of serum was already elicited at the end of the ischemic period. Furthermore, the TRAP of serum increased with the increasing duration of early postischemic period. Among the antioxidants studied, urate and ascorbate concentrations exerted the highest correlation with TRAP, but 31.6% of the total antioxidant capacity remained for the activity of an unidentified antioxidant(s). After being exhausted, the TRAP of serum oscillated around the preoperation level at days 1-4 of the postischemic period. The increase in total antioxidant capacity of serum induced by oxidative stress was sufficient to prevent lipoperoxidation both in serum and intestinal tissue.

Animals↗
PubMed1997

Leukocyte mobilization, chemiluminescence response, and antioxidative capacity of the blood in intestinal ischemia and reperfusion.

Intestinal ischemia and reperfusion elicits changes in leukocyte counts and increased production of reactive oxygen species (ROS). The purpose of this study was to investigate whether these changes were followed by and/or connected with changes in the extracellular antioxidative capacity in a rat superior mesenteric artery (SMA) occlusion/reperfusion model. The SMA was occluded for 45 min and then allowed to be reperfused. Changes of leukocyte, polymorphonuclear (PMN), and lymphocyte counts, chemiluminescence (CL) of whole blood samples as a marker of ROS production, and the total antioxidative capacity of the serum were quantified at the end of ischemia and in 1 h intervals during the postischemic period up to 4 h. The myeloperoxidase (MPO) activity in the serum and intestinal tissue samples was also determined. The MPO activity in the intestinal tissue samples was significantly elevated at the end of ischemia, and this elevation lasted for the whole postischemic period. The oxidative challenge to the body induced a fast mobilization of extracellular antioxidative mechanisms already at the end of ischemia, which was followed by a significant increase in PMN counts and whole blood CL starting at the 2nd hour after reperfusion. The increased CL activity of whole blood was attributed to the increase of the circulating PMNs. No significant changes were observed in leukocyte and lymphocyte counts. It is concluded that compensatory mechanisms of the oxidative-antioxidative balance of the body react very quickly if challenged.

Animals↗
PubMed1997

Effects of recombinant rat tumor necrosis factor-alpha and interferon-gamma on the respiratory burst of rat polymorphonuclear leukocytes in whole blood.

Activated polymorphonuclear leukocytes (PMNL) might be an important source of host tissue damage. PMNL may be primed by various inflammatory mediators for an increased production of reactive oxygen species (ROS). The short-term priming effects of two cytokines, interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), on rat PMNL in whole unfractionated blood were investigated in the present study. Incubation of PMNL with cytokine alone did not induce the detectable ROS production without addition of a second stimulus-phorbol myristate acetate (PMA) or opsonized zymosan particles (OZP). One-hour incubation with TNF-alpha, or the mixture of TNF-alpha + IFN-gamma resulted in a dose-dependent enhancement of ROS production in response to PMA. Moreover, the incubation with both IFN-gamma and TNF-alpha caused a significantly higher increase of ROS production than with TNF-alpha alone. However, no priming effects of IFN-gamma on the PMA-induced ROS production were observed. Finally, none of the cytokines enhanced the total production of ROS upon the stimulation with OZP, although changes in the time course of ROS production were observed. Thus, different signal transduction pathways seem to be involved in PMA- and OZP-induced respiratory burst. Alternatively, partial activation and assembling of NADPH oxidase during cytokine treatment might explain the differences observed between PMA- and OZP-induced ROS production. The results of the present study suggest that IFN-gamma may enhance the priming effects of TNF-alpha. This finding may have implications for understanding the mechanisms by which both cytokines may contribute to PMNL-mediated tissue injury during various clinical conditions, as well as to host defense against invading pathogens.

Animals↗
PubMed1996

Determination of phagocyte activity in whole blood of carp (Cyprinus carpio) by luminol-enhanced chemiluminescence.

In this study, the phagocytic capacity of fish peripheral blood leucocytes was studied using the luminol-enhanced chemiluminescence (CL) method. Suspensions of rice starch (1%) or opsonized zymosan particles-OZP (0.2%) were used as activators. The level of CL was detected at 25 degrees C in various whole blood volumes (100, 50, 20 a 10 microliters) during the mixed or unmixed measurement mode. The peak of CL in all starch-activated samples was between 2.0-4.0 mV, regardless of blood volume or a mode of measurement. Similar results were obtained for OZP activated CL when measured in the mixed mode. On the other hand, the peak of OZP activated CL in unmixed samples was much higher and it showed positive correlation with the increasing volume of blood in a sample. In contrast, no significant differences between the reaction curve areas were found for different blood volumes. After correction for phagocyte number the highest CL activity per cell was observed in the samples containing 10 microliters of blood. It can be concluded that 10-20 microliters of blood are optimal volumes for the measurements of respiratory burst activity in the whole blood of carp and opsonized zymosan particles should be used as an activator. At the same time, the unmixed mode of measurement seems to give better results than the mixed one.

Animals↗
PubMed1995

[Risk of diabetes mellitus, variations in glucose tolerance, insulin secretion and lipid parameters in offspring of diabetic mothers].

BACKGROUND: Children of diabetic mothers are a relatively new population group which started its existence due to revolutionary changes in the treatment of insulin-dependent diabetes during pregnancy. In the Institute for the Care of Mother and Child since the fifties comprehensive care of diabetic mothers was concentrated and thus it became possible to follow-up a relatively large group of their children to adult age. METHODS AND RESULTS: The authors investigated 176 children of diabetic mothers (CDM) aged 20.75 +/- 0.31 years. All mothers suffered from insulin-dependent diabetes mellitus (IDDM). In 7.95% CDM diabetes developed at the age of 11-23 years (IDDM in 4.54% and NIDDM in 3.41% of CDM). An impaired glucose tolerance was revealed in 6.25%. The mean blood sugar level during the oral glucose tolerance test was significantly higher than in a control group of 31 subjects of the same average age without a family-history of diabetes (p < 0.01). The ratio of insulinaemia to the blood sugar level was markedly higher not only when the glucose tolerance was impaired (p < 0.005) but also in CDM with a normal glucose tolerance (p < 0.025). The total cholesterol and triacylglycerol levels did not differ from the control group. In the group of DDM with an impaired glucose tolerance the non-esterified fatty acid levels were higher, as compared with controls (p < 0.05). CONCLUSIONS: The results of the described group of CDM which is one of the groups followed-up for the longest period reported in the literature indicate the risk of children of diabetic mothers and the necessity to follow-up and screen subclinical signs of the disease.

Adolescent↗
PubMed1994

[Short-term variability of fetal cardiac activity in 1F and 2F behavioral states].

The investigation revealed intraindividual differences in characteristics of the short-term variability of cardiac action of normal foetus during the tenth month of pregnancy in the phase of behavioural state 1F and 2F. These conditions, in particular state 1F, are otherwise frequently the cause of false positivity of the non-stress test during antepartum monitoring because the values of the parameter of short-term variability of FHR when reading the hard print of the cardiotocogram can permit also an interpretation suggesting the diagnosis of chronic foetal hypoxia. Simultaneously the authors proposed and tested a simple supplementing device which makes it possible to evaluate continuously selected parameters of the short-term variability of cardiac action for the needs of antepartum monitoring.

Female↗
PubMed1993

[Development and interrelations between certain respiratory and biochemical parameters in normal neonates].

The authors investigated the development and interrelations of respiratory and biochemical parameters of normal neonates during the adaptation period from 15 minutes to the 7th day after delivery. They found that the correlations of oxygen consumption, carbon dioxide output, respiratory volume and minute ventilation are positive and independent on the time of assessment. These respiration parameters are independent on the glucose, lactate and pyruvate levels, on the respiratory quotient and pH and pCO2. The authors characterize the similarity of the trend of individual parameters and the variability of normal values.

Blood Glucose↗
PubMed1991

[Development of attention in early childhood].

Based on observations of a group of 16 healthy newborn mature babies the authors describe the development of attention during the first six months of life. Analysis of data revealed the importance of age and individual differences. We investigated an interrupted attention (lasting half a minute or longer) focused on the face of adults and a suspended toy, and interrupted attention (lasting for a period less than half a minute with an interruption not longer than half a minute). The curve of uninterrupted attention paid to the face of an adult had the shape of an inverted letter "U". As regards uninterrupted attention devoted to toys this type of curve was less expressed. Interrupted attention increased continuously with age. Individual differences between children throughout the investigation period displayed considerable stability.

Attention↗