National Repository of Grey Literature 32 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Testing of drugs embryotoxicity on chicken embryo
Steklíková, Klára ; Peterka, Miroslav (advisor) ; Buchtová, Marcela (referee)
The embryonal development could be negatively disrupted by exogenous factors, which could cause developmental defect. These factors are called teratogens and amongst them there are not only physical and biological but also chemical substances including some of commonly used drugs. Those substances are recommended not to be use in pregnancy. In case of women with chronical disease, for example diabetes mellitus, permanent medication is necessary also during pregnancy. Therefore it is important to ensure medicament and dose, which are safe for use during pregnancy. For finding out the embryotoxicity of drugs the prospective and retrospective epidemiological studies are used, which are supplemented by results from experimental studies. According to OECD (organization for economic co-operation and development) recommendations the classical testing is performed on two different mammalian species. Those experiments are limited by different pharmacokinetics and biotransformation, which affects substances in maternal organism. Therefore for alternative embryotoxicity testing are used such methods, that exclude this impact. One of these model organisms that enable this is chicken embryo. Chicken embryo, unlike cellular and tissue cultures, can provide complex information about effect of tested substance on...
Embryotoxicity testing of psychopharmacs using the CHEST method
Pavlovič, Ondřej ; Peterka, Miroslav (advisor) ; Maňáková, Eva (referee)
Psychotropic drugs are commonly used group of pharmaceuticals, their main effect is to alter psychic condition, including mental diseases treatment. Symptoms of mental illnesses are more and more common, theref orenumber of patients diagnosed with mental illnes, and thus using psychotropics, is growing stronger. But using psychotropics during gestation is not without risks for mother and embryo itself. However, thanks to the absence of controlled human studies, the knowledge of emrbyotoxic effects of pschotropics is limited to casuistics, reported side effects and animal experimental studies. Many of those studies suggests emrbyotoxic potential of psychotropic drugs, on the other hand, others claim their safety. The goal of this thesis is to test at least some of them, using CHEST method, that allows us to observe direct effect of unmetabolized substance on chick embryo. In this thesis we tested selected psychotropics, very common antidepressant fluoxetine (prozac) and antipsychotic drug olanzapine, for embryotoxicity, using in ovo method CHEST with chick embryos as model organism. By bypassing the maternal organism and his metabolism, this method allows to observe direct effect of unmetabolized substance on chick embryo. Results revealed embryotoxic effect of fluoxetin in dosage 10-2 and 10-3 on 3rd and...
Functional role of ISLET1 in the neurosensory development of the inner ear.
Hampejsová, Zuzana ; Pavlínková, Gabriela (advisor) ; Peterka, Miroslav (referee)
Loss of hearing affects more than 10 % of the population, and one newborn in a thousand is born with defects of the inner ear. Transcriptional factors involved in the development of inner ear are important in our understanding of the causes of inner ear defects. ISLET1 is one of these factors. ISLET1 expression is detected in the sensory and neuronal cells of the inner ear. It participates in otocyst formation, and the specification and differentiation of cells of cochlea and vestibular system. The functional role of ISLET1 during inner ear development was investigated. Its role was studied by using Pax2-Isl1 transgenic mice that overexpress Islet1 under the control of the Pax2 promoter. Two transgenic lines were generated, Pax2-Isl1/300 and Pax2- Isl1/52. Two copies of the Pax2-Isl1 transgene were inserted to Pax2-Isl1/300 genome and one copy was inserted to the Pax2-Isl1/52 genome. Defects in sense of hearing were detected in both lines and circling behavior, a defect of balance, was detected in the Pax2-Isl1/300 transgenic mice. We observed high postnatal lethality in heterozygote transgenic mice. Pax2-Isl1/52 homozygote mutation is lethal at embryonic day 10 (E10,5). Pax2-Isl1/300 homozygote letality couldn't be detected because of the inability to breed heterozygote mutated mice of this line....
New modified method of neonatal cleft lip surgery
Borský, Jiří ; Peterka, Miroslav (advisor) ; Jirásek, Jan Evangelista (referee) ; Měšťák, Jan (referee)
2 2. Abstract Cleft palate is one of the most frequent congenital malformations. The complexity of these conditions requires surgical treatment in several stages. The first stage includes reconstruction of the nose and the lip, and timing is either shortly after birth, or, in about two thirds of centers worldwide this surgery is performed at the age of 3 months. The next stage, palate defect repair, is timed at around 9 months of age, and the final reconstruction of the maxilla is done based on the permanent canine eruption at about 8 years of age. The main objective of our study was to estimate the pros and cons of early surgical approach after introducing a novel modified surgical protocol versus the conventional surgical protocol. The 5 main findings include: 1. A novel surgical procedure to repair neonatal cleft lip was developed, incorporating modification of Tennison protocol by adding flaps acquired from the margins of the cleft. An important contribution is a shorter time both under anesthesia and in the theatre, and resulting reduction of hospital stay from 7-8 days down to 3-4 days. 2. We have compared the biochemical parameters of the surgical wound healing - matrix metaloproteases (MMP) and their inhibitors (TIMP) in the group of children having surgery early in neonatal age and in children...
Embryotoxicity test of insulin-glucose interaction
Vobrová, Renata ; Peterka, Miroslav (advisor) ; Peterková, Renata (referee)
Diabetes mellitus is heterogeneous group of diseases. Their common characteristic is failure of metabolism carbohydrate, fats and proteins which is caused by an absolute or relative lack of insulin. A lack of insulin leads to the hyperglycemia. If diabetes is present, glucose and insulin, which physiologically occur in a body, are not in a balance. Pregnant women with diabetes have 7x - 10x higher risk of incidence offspring congenital malformations and there is also 2x - 5x higher risk of neonatal death compared to a population of healthy women. There have been disputes whether the teratogenic potential should be attributed to insulin, glucose, or whether the teratogenic effect of these substances increases through interaction. There is a question how much can maternal organism with diabetes disorder participate to the formation of congenital defects. The embryotoxic effects of insulin itself is not possible to study in the experiment on mammals, because it is not possible to distinguish the effect of the substance itself from the effects of disturbed metabolism of the maternal organism. The unique opportunity is to test the chicken embryo that develops outside the maternal organism. Therefore, we choose the aim of this thesis a test method CHEST (single application 2nd - 5th embryonal day) and a...
Embryotoxicity test of thyroxine on chick embryo.
Petrušková, Michaela ; Peterka, Miroslav (advisor) ; Novotná, Božena (referee)
Thyroxine is the main thyroid gland's hormone. The state, when the thyroid gland does not produce enough of it into the bloodstream is called hypothyroidism. Hypothyroidism is related with several health complications; therefore it is required to take replacement therapy in adequate doses. Concerning pregnant women, it is important especially to keep the blood level of thyroxine in the normal, because increasing or decreasing of it, has an adverse effect on the health of the mother and also on the normal child development. The objective of my thesis was to describe malformations spectra of thyroxine, to find out the beginning of its embryotoxicity dose range for chick embryos, and recalculate this value for human embryos, allowing us to decide, if the level of thyroxine was increased by a replacement therapy, this could be embryotoxic for human. The experimental part of my work was to search an alternative method for testing embryotoxicity on chick embryos in ovo - CHEST, testing of embryotoxic potential of the thyroxine. Embryotoxicity is a feature of the external factors affecting the embryo, it may manifest as lethality, growth retardation, and teratogenicity; which is an ability of the external factor to induce the developmental defect. The most common manifestation of embryotoxicity in this...
Effect of addictive drugs on prenatal development
Hofmannová, Oldřiška ; Peterka, Miroslav (advisor) ; Peterková, Renata (referee)
Substance abuse is long-term worldwide problem. This thesis summarizes findings about the effects of stimulants, opiates and hallucinogens and focuses on the most commonly used illegal representatives of individual groups: cocaine, amphetamines, heroin and LSD. All these substances have negative effect on both mother and her fetus. Some of addictive substances can influence pregnancy and childbirth. There is also higher risk of fetus mortality and morbidity of the new born baby. Prenatal exposure to addictive substances could have influence on the birth weight, length, head circumference, its further growth and behavior. Some drugs can cause neonatal abstinent syndrome which can lead without prenatal care to death of newborn.
The comparation of embryotoxical effect of insulin and glucose by the method CHEST.
Turková, Aneta ; Peterka, Miroslav (advisor) ; Likovský, Zbyněk (referee)
If gravid women suffer from diabetes,their unborn children have 10x higher risk of development of malformation,prenatal and postnatal death and post partum complications than children of women belonging to healthy population.The main and very controversial potential teratogenic factors are glucose and insulin.However,there are very ambivalent opinions on which one of these two substances causes damage to embryo. Therefore,the aim of this diploma thesis was to contribute to solving of this problem and test direct embryotoxicity of insulin and glucose. For solving of this issue, the so-called CHEST.The principle of this method is creation of a window in eggshell and consequent subgerminal or intraamnial application of the substance being tested.Embryos were tested from the second until the sixth incubation day.Firstly, two types of insulin were injected.Injected doses varied between 3µg/3µl to 0,003µg/3µl. Then glucose was tested,with dosage of 300µg/3µl and 30µg/3µl. Embryotoxic effect was detected for both types of insulin. The beginning of embryotoxicity line of insulin's lies between the dosage of 0,03µg/3µl and 0,003µg/3µl. From embryotoxic effect, death of embryos predominated over development of congenital malformations. Only after application on the second incubation day, there was increased...
Testing of embryotoxicity of selected human teratogenes on chicken embryos.
Pavlíková, Zuzana ; Peterka, Miroslav (advisor) ; Novotná, Božena (referee)
Teratogenes are external environmental factors that can cause a developmental or a congenital defect in exposed individuals. The methods used for detecting the embryotoxic effect of substances are the classic when laboratory mammals are used and the alternative which use in vitro and in ovo systems. The main difference between these two is that the alternative methods lack metabolism of maternal organism. The metabolism of maternal organism brings a high variability of results to systems of the classic methods. We used two alternative methods in this thesis, both using chicken embryo. The first of them was in ovo method called CHEST (Jelínek, 1977). CHEST method can be used for administration of tested substances from ED2 to ED6. The disadvantage of this method is due to the dilution of the tested substance after subgerminal application at ED2. Therefore we developed in vitro method called SANDWICH. No dilution occurs while using the SANDWICH method. The aim of this study was to develop in vitro method SANDWICH while using proven teratogene (all-trans retinoic acid) and its solvent (dimethyl sulfoxide), to estimate beginning of the embryotoxicity dose range for both substances using CHEST and SANDWICH, and finally to compare obtained results. We confirmed the embryotoxic effect of all-trans...

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See also: similar author names
4 PETERKA, Michal
6 Peterka, Martin
2 Peterka, Matěj
4 Peterka, Michal
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