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Biomedical subjects

J Koudelová

Publications and source records attributed to J Koudelová.

At least 19 recordsLinked to original sources
PubMed2006

[Peripheral primitive neuroectodermal tumor -- PNET].

The authors describe three cases of peripheral primitive neuroectodermal tumor. The tumor was found in soft tissues of the crus, shoulder girdle and perineum, and was also located paravertebrally and epidurally at the level of L1-L2 vertebrae. Radiological findings were not specific for this disease. The results of imaging methods (sonography, CT, MRI, DSA) were important for the assessment of tumor size, its boundary and invasion of the surrounding tissues, and for the evaluation of tumor response to therapy and detection of recurrent disease. The PNET diagnosis was based on immunohistochemical, biochemical and cytogenetic examinations. One patient died 5 months after the first clinical signs were manifested; the two patients surviving for 2 and 1 3/4 years after first sign manifestation, respectively, remained in the care of cancer specialists. Key words: skeletal Ewing's sarcoma, extra-skeletal Ewing's sarcoma, Ewing's sarcoma family of tumors, peripheral primitive neuroectodermal tumor.

Adolescent↗
PubMed2005

Developmental changes of erythrocyte catalase activity in rats exposed to acute hypoxia.

The erythrocytes represent an important source of antioxidant capacity of the blood. Catalase (EC 1.11.1.6.) is one of the enzymatic components of their antioxidant defense system. The objective of this study was to follow erythrocyte catalase (CAT) in 7-, 15-, 21-, 35-, 60- and 90-day-old Wistar rats of both sexes in normoxia and after exposure to intensive acute hypobaric hypoxia. During the development CAT activity increases in both sexes, but the rise was usually higher in females. Hypobaric hypoxia increased CAT activity in all studied age groups of both sexes. However, higher CAT activity in females was less affected by hypoxia than the lower activity in males. This was true for nearly all age groups studied. It can be concluded that both ontogenetic aspects and sex differences play a major role in establishing the activity of CAT, which is an important part of the antioxidant defense of the organism.

Acute Disease↗
PubMed2005

Biochemical markers and genetic research of ADHD.

ADHD (attention hyperactivity disorder) is a polygenetic disorder with various candidate genes. At this time, more than thirty dopaminergic, noradrenergic, serotonergic and GABA-ergic genes are known. The research of only some candidate genes (DRD4, DAT, DRD5, DBH, 5HTT, HTR1B and SNAP25) brought relatively consistent results confirming the heredity of ADHD syndromes. The results of research of other genes (DRD2, DRD3, MAO, ADR2A, GABA A3, GABA B3) are not clear yet. This paper summarizes the most important genetic data in correlations with biochemical periphery parameters (especially for DBH, HVA, MHPG, serotonin). Hypothetically, certain subgroups of ADHD may be identified by correlation of biochemical characteristics and some candidate genes. The paper discusses some implications for future research. Review.

Attention Deficit Disorder with Hyperactivity↗
PubMed2005

[Metaphyseal fibrous defect].

PURPOSE OF THE STUDY: The aim of the study was to identify predisposition to the development of metaphyseal fibrous defect (MFD) on the skeleton and to select appropriate imaging methods and examination for detection of atypically located or larger cortical lesions. MATERIAL: A group of 38 randomly selected patients with MFD was analyzed. It comprised of 27 boys and 11 girls at average ages of 13.7 years and 15.5 years, respectively. The youngest child was 4 and the oldest patient was 30 years old. METHODS: Thirty-two patients with a history of trauma and six patients with problems associated with sports activities were examined by plain radiography. Additional examination included CT scans in eight, MRI in two, scintigraphy in 17, angiography in seven and genetic examination in three patients. Histological evaluation confirming the presence of MFD was carried out in seven patients. RESULTS: The majority of lesions (75.6 %) were found around the knee, 17 in the distal femur and 17 in the proximal tibia. Eight lesions (17.8 %) were present in the distal tibia and three (6.6 %) were at other sites. Multifocal lesions, when detected, were associated with von Recklinghausen's neurofibromatosis, Marfan's disease or familiar occurrence. In most cases the diagnosis was made on the basis of plain radiographic findings. For large lesion in atypical locations, examination by CT, MRI, scintigraphy or biopsy were recommended. DISCUSSION: In this section the authors discussed other pathologic conditions that must be distinguished from MFD. CONCLUSIONS: The bones around the knee were affected most often. Multifocal MFD lesions were associated with von Recklinghausen's neurofibromatosis, Marfan's disease or familiar occurrence. The diagnosis was usually based on plain X-ray examination. To diagnose atypical and large lesions, advanced imaging (CT, MRI), scintigraphy or biopsy were recommended.

Adolescent↗
PubMed2004

Changes of dopamine-beta-hydroxylase activity during ontogenesis in healthy subjects and in an experimental model (rats).

In children and adolescents (250 healthy subjects) serum dopamine-beta-hydroxylase (DBH) activity (23.9+/-5.2 to 57.1+/-17.5 micromol/min/ml) increases with the age between 3-10 years, later it decreases approximately by the age of 10-14 years. At the age of 21 to 60 years DBH level is stable. Our study described decreasing DBH activity in adolescents at the age of 10-14 years in the studied sample of healthy persons. Experimental animals (200 Wistar rats, 5-120 days old) show the same trend of enzymatic activity, similarly as in humans. DBH activity in rats is between 0.85+/-0.1 to 2.8+/-0.05 micromol/min/ml. This activity is highest in 5-day-old rats; it decreases till the age of 14 days and increases mainly in 14- to 35-day-old animals. Decrease of DBH activity in rats between 35 to 40 days is significant and corresponds to the reduction of DBH activity in adolescent humans (10-14 years). Adult rats (aged 90-120 days) show a stable DBH activity. DBH activity intermediately decreases in 10- to 14-year-old children. This decrease corresponds to the intermediate developmental changes of electrophysiological parameters (decreasing EEG activity in healthy adolescents occurs in 10-14 years old children). Puberty is coupled with intermediate decreasing of DBH activity in man and also in experimental animals in the period of prominent psychological and physiological changes.

Adolescent↗
PubMed2003

[Primary hyperparathyroidism (osteitis fibrosa cystica generalisata Recklinghausen)].

The case of a 67-year-old man presenting with parathyroid gland adenoma associated with multiple organ manifestations of a rare normocalcemic form of primary hyperparathyroidism is described. The authors draw attention to the importance of correlating clinical and laboratory examinations with histological, radiological and scintigraphic findings for the establishment of diagnosis. They emphasize the role of two-phase 99mTC-MIBI (methoxyisobutyl-isonitril) scintigraphy not only for diagnostic purposes but also for exact localization of the adenoma by means of a gamma probe during surgery. They also point out the possibility of accompanying pathological conditions, in this case, the development of a tumor described as "brown tumor". This was shown by angiography as a hypervascularized and strongly stained expanding lesion. The authors conclude that the early surgical removal of this parathyroid gland adenoma was important for the patient's successful recovery.

Aged↗
PubMed2002

[Periosteal desmoid].

The authors describe a rare benign disease occurring in children and adolescents with an increased physical activity at the age of 8-20 years. It is a tumour-like lesion developed by a repeated micro-trauma of the origin of distal fibres of adductor magnus and aponeurotic origin of the medial head of the gastrocnemius. This disease must be paid increased attention as in the region of the knee joint in children it is a location of a frequent development of sarcoma and osteomyelitis. With the knowledge of this lesion such cases may be diagnosed merely by a classic radiograph, preferably in external rotation and CAT and MRI examinations. Of the highest value for the examination is the CAT examination. Radiograph changes are located in the region of the distal part of the medial crest of linea aspera, tuberculum adductorium and posteromedial part of the medial epicondyle of femur.

Adolescent↗
PubMed2001

Carnitine pretreatment can partially change the excitability of the immature nervous tissue.

The possible protective action of L-carnitine on neuronal excitability was studied in 21-day-old male Wistar rats with implanted electrodes. Administration of L-carnitine did not change the elicitation and duration of the epileptic seizures (cortical afterdischarges, ADs) in rats under normobaric oxygen atmosphere conditions. However, in animals exposed to 30 min hypobaric hypoxia the duration of the ADs was shortened after the second, fourth and sixth stimulation (in comparison with the first evoked ADs) while carnitine-treated rats retained their neuronal excitability and the duration of ADs was shortened only after the third stimulation.

Animals↗
PubMed1999

The role of membrane fluidity changes and thiobarbituric acid-reactive substances production in the inhibition of cerebral cortex Na+/K+-ATPase activity.

Lipid peroxidation of rat cerebral cortex membranes was induced by Fe2+/ADP and ascorbate. The rate of Na+/K(+)-ATPase inhibition was correlated with the increase of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD) and with membrane fluidity changes. Our data showed that membrane fluidity changes (evaluated by fluorescence steady-state anisotropy measurements) can participate in Na+/K(+)-ATPase inhibition during the initial period of lipid peroxidation process, whereas during the following period the enzyme inhibition correlates only with TBARS and CD production.

Adenosine Diphosphate↗
PubMed1997

[Adrenergic tocolytics--their effects on lipoperoxidation in the brain].

As a sequence of our previous investigations and published results dealing with the inhibitory effect of the BETA-mimetic Tocolyticum (Partusisten) on the blood plasma levels of polyunsaturated fatty acids (n-3), we performed experiments where the possible inducing effect of BETA-mimetic drugs (epinephrine and isoprenaline) on the lipoperoxidative processes in the brain and liver was studied. (Adult rats-females.) Lipoperoxidation was tested by the method of Ohkawa and al. [21] based on changes in malondialdehyde (MDA) production. The intraperitoneal administration of isoprenaline (0.15 mg/kg body weight) increases significantly the MDA production in the cerebral cortex as well as in the medulla oblongata of rats (females-Wistar). Isoprenaline induces a small but significant decrease of MDA in the liver. The intraperitoneal administration of epinephrine (0.15 mg/kg body wight) raises significantly the MDA production in the cerebral cortex as well as in the medulla oblongata. In hepatic tissue changes in MDA levels were not observed. The mentioned data indicate that the decrease of polyunsaturated fatty acids (esp. of n-3 series) in plasma of human newborns and their mothers treated by BETA-mimetic tocolytic drugs (as Partusisten), could be associated with the significant higher lipoperoxidation. The clinical use of such tocolytic drugs has to be discussed also from this point of view.

Adrenergic Agonists↗
PubMed1994

Protective effect of carnitine on lipoperoxide formation in rat brain.

Carnitine administration (by intraperitoneal injection) to 21-day-old-rats prevents the increase of thiobarbituric acid-reactive substances (index of lipid peroxidation and free radical damage) induced by 30 min hypobaric hypoxia in four different parts of the brain (cerebral cortex, subcortical structures, medulla oblongata and cerebellum).

Animals↗
PubMed1994

The lipid peroxidation in various parts of the rat brain: effect of age, hypoxia and hyperoxia.

The effect of normobaric oxygen atmosphere on hypoxia-enhanced lipid peroxidation in the brain cortex, subcortical structures, medulla oblongata and in the cerebellum was observed in 7- and 21-day-old and adult rats. The production of free oxygen radicals causing lipid peroxidation was assessed by the method described by Ohkawa et al. (1979). The rats were exposed for 30 min to 100% oxygen atmosphere which significantly stimulated the production of malondialdehyde (MDA) in all the studied regions of the brain in 7- and 21-day-old male rats, and in the brain cortex and subcortical structures of adult males. Higher levels of MDA were found in the brain cortex of 7-day-old female rats only. Reoxygenation with pure oxygen after 30 min hypobaric hypoxia corresponding to 9000 m increased MDA production in all studied parts of the brain on both male and female rats 7- and 21-day-old. In adult rats significantly increased MDA production was only found in the brain cortex of male and female rats and in the subcortical structures of males. The exposition to hypobaric hypoxia followed by reoxygenation by atmospheric air enhanced MDA production in all studied regions of the brain in 7-day-old males and in the cerebellum of females; in 21-day-old rats of both sexes a significant increase of MDA was detected in all parts of the brain. In adult rats were found higher MDA levels in the cerebral cortex of both males and females.

Aging↗
PubMed1993

Lipid peroxidation in isolated membranes of cerebral cortex, heart and kidney.

The extent of ADP.Fe/NADPH-induced lipid peroxidation measured as production of thiobarbituric acid-reactive substances (TBARS) was determined in isolated membranes from cerebral cortex, heart and kidney of 21-days-old rats. The time course of lipid peroxidation showed higher production of TBARS in cerebral cortex than in heart and kidney. Our data indicate that high level of TBARS production is not due to high activity of NADPH oxidoreductase but due to high content of endogenous lipids in cerebral cortex membranes that could be modified. Higher production of TBARS in cerebral cortex is the result of higher content of lipids in cerebral cortex membranes because NADPH cytochrome c reductase activity in membranes of cerebral cortex is lower than that of heart and kidney.

Adenosine Diphosphate↗
PubMed1992

Different degrees of lipid peroxidation in the CNS of young and adult rats exposed to short-term hypobaric hypoxia.

The authors studied the effect of short-term (20 min) hypobaric hypoxia at simulated altitudes of 7000 and 9000 m on the peroxidation of lipids in the cerebral cortex, subcortical formations, medulla oblongata and cerebellum of the laboratory rat. In 5- and 21-day-old rats, increased lipoperoxidation was recorded in all the studied regions of the brain. Differences were observed in sensitivity to the degree of hypoxia. In 5-day-old rats the response to both exposures was the same, but in 21-day-old animals exposure at 7000 m stimulated peroxidation in the cerebral cortex only (at 9000 m in all the parts of the CNS examined). In 35-day-old and adult rats, changes in the malondialdehyde concentration were likewise found after exposure at 9000 m, but not in every compartment (in 35-day-old rats in the cerebral cortex and subcortical formations and in adult rats in the cerebral cortex). In young rats, 30 and 60 min after exposure to hypoxia the malondialdehyde concentration was still higher than in older animals.

Aging↗
PubMed1991

[The effect of intraperitoneal administration of adrenaline on ascorbic acid levels in the brain, adrenal glands and blood in rats of various ages].

Male and female rats (Wistar strain), 5 days old and full grown rats (cca90-120 days) were used for experiments where the authors investigated the effect of adrenaline SPOFA, 0.15 mg/kg body weight administered by the i.p. route, on the ascorbic acid content in the cerebral cortex, in the mesencephalon, cerebellum and medulla oblongata, as well as in the adrenals and plasma. Ascorbic acid was assessed by Roe and Kuether's method (19). The control group was formed by intact rats or a group where saline in analogous amounts (volume) was administered by the i.p. route. Tissues and plasma were processed 30 min. after administration of adrenaline (saline). The method of processing and collection of tissue specimens was described repeatedly in the past (10, 16). It was revealed that 5-day old rats regardless of sex have after administration of saline or adrenaline a higher ascorbic acid concentration in the brain (more frequently significant changes were found in males-incl. plasma). The same applies to the group of full grown males. In full grown females there is usually a decline of the ascorbic acid concentration in the brain (injection and administration of saline is more effective than adrenaline). In full grown rats concurrently a marked rise of the plasma concentration of ascorbic acid occurs.

Adrenal Glands↗
PubMed1990

Influence of age, sex and hypoxia on plasma dopamine-beta-hydroxylase activity in the rat.

Using rats (Wistar strain) of our own breed, we studied dopamine-beta-hydroxylase (E.C. 1.14.17.1) (DBH) activity in the plasma of animals of different ages (in correlation to sex) under normal conditions and after exposure to altitude hypoxia (corresponding to 7000 or 9000 m and lasting 20 min). The enzyme was determined by the method of Kato et al. (1974). We found that the given plasma enzyme activity was significantly higher in females than in males, throughout the whole life-span. In addition, we found that minimum activity was reached on about the 14th and 21st day of postnatal life and again on the 40th day, while maximum activity was recorded at the ages of 5, 30 and 35 days and in adult rats. In adult animals (males and females), exposure to altitude hypoxia was followed by a statistically significant increase in plasma DBH activity, which was much more pronounced in females than in males. In males, 240 min after terminating hypoxia plasma DBH activity had returned to normal, but in females it was still significantly raised; after 48 h, plasma DBH activity in females was identical to the activity before exposure to hypoxia. In rats aged 5 and 35 days, hypoxia evoked a fluctuating response. A decrease in activity immediately after terminating hypoxia was followed at 60 min by a return to normal, but at 240 min there was again a significant decrease. In 21-day-old rats, hypoxia did not induce any significant change in plasma DBH activity (the initial activity level in this group was very low).

Aging↗
PubMed1990

[The effect of one-time and repeated starvation on dopamine beta-hydroxylase serum activity in rats of various ages].

The authors used for experiments Wistar strain rats, 5 days old and adult rats, and investigated the activity of plasma dopamine-beta-hydroxylase after exposing the rats to a single 24-hour or repeated 3 X 18-hour fast and fluid deprivation on three consecutive days. They found that in both age groups, in males as well as females, both mentioned types of nutritional stress (deprivation) led to a marked reduction of activity of the plasma level of the mentioned enzyme. This reduction was in both types of fasting roughly equal when expressed in absolute or relative figures. The enzyme activity was assessed by a method described by Kato (4) and is expressed in nmol/l ml plasma/min. The statistical evaluation was made by the Biocybernetic department of the Institute of Physiology, Faculty of General Medicine, Charles University, Prague.

Animals↗