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O Török

Publications and source records attributed to O Török.

At least 19 recordsLinked to original sources

Quality assurance in obstetric and gynecologic ultrasound. The Hungarian model.

The majority of physicians performing obstetric scans are radiologists and obstetricians. The radiologist is well trained in imaging but lacks the obstetric background required to interpret information obtained from the scan. The obstetrician is qualified in obstetric knowledge but often lacks the formal imaging training necessary to optimize the pictures. In Hungary, nearly 100% of the physicians who perform obstetric and gynecologic scans are obstetricians. In order to create a standard and to hold together the practitioners in obstetrics and gynecology, as well as to eliminate the serious consequences of clinical malpractice, we organized the Hungarian Society of Ultrasound in Obstetrics and Gynecology in 1992. The Society was established according to the standards of the most skilled obstetricians and gynecologists. In addition to working out the conditions and the standards, the Society provides for its members continuous education, postgraduate training, and monitors the knowledge and level of practitioners. We have established three levels of qualification. Each level requires a medical undergraduate degree. The levels range from basic (A), intermediate (B), to specialist (C). To receive the certificate every user and ultrasound laboratory have to fulfill requirements based on skill as well as equipment and circumstances. The certificates are valid for one year. Every year the practitioner must pass a special examination at the appropriate level. By doing so, the Society provides its members with not only professional support, but ethical and legal security as well.

Certification↗

[Biochemical and ultrasonic screening of chromosomal aneuploidies in the second trimester of pregnancy].

For prenatal screening of chromosomal aneuploidies (primarily the most frequent Down syndrome) maternal serum AFP screening in the second trimester of pregnancy has been supplemented by the determination of hCG in Hajdú-Bihar county. In pregnancies at risk on the basis of biochemical tests, a thorough, aimed ultrasound examination for the detection of minor and major anomalies characteristic for chromosomal abnormalities was carried out. If both biochemical and ultrasound examinations were suggestive of high risk prenatal karyotyping was offered. During a two-years prospective study 14328 pregnancies were screened. Authors could detect 38% of Down-syndrome cases prenatally, 5 cases in pregnant women at age under 35 years and at the same time the number of amniocenteses increased only by 70. It was concluded that 66% of all Down syndrome cases could have been prenatally diagnosed if prenatal chromosome test were performed in all cases at high risk on the basis of screening tests and maternal age.

Adult↗

[Screening for congenital anomalies in mid-term pregnancy. Prospective epidemiologic study. Fetal trisomy].

The authors have presented their experiences on prenatal screening of fetal trisomies in this second part of a prospective study between 1988 and 1990. They gained their conclusions by processing 63,496 pregnancies during three years. The results show that maternal age plays the most important role in the prenatal screening of fetal trisomies in Hungary. They recommend fetal karyotyping for every pregnant woman aged 35 years or more. They emphasized that using of a combined screening method (i.e. maternal age, serum alpha-fetoprotein, human chorionic gonadotropin, oestriol) is only permissible if the hormonal and cytogenetic laboratory background are provided under standard circumstances. Since these are not available for the vast majority of pregnant women in Hungary they concluded that, at least for the time being, the main criteria for prenatal screening of fetal trisomies is the maternal age. By applying this recommendation 25-30 percentage of Down syndrome fetuses can be detected.

Adult↗

Impact of prenatal mid-trimester screening on the prevalence of fetal structural anomalies: a prospective epidemiological study.

The objective of this study was to evaluate the effectiveness of the measurement of maternal serum alpha-fetoprotein (MSAFP) at 16 weeks and a subsequent routine ultrasound screening at 18-20 weeks' gestation and the impact on the birth prevalence of congenital structural anomalies in an unselected pregnant population of Hungary in a prospective epidemiological study. A total of 63,794 pregnant women (representing one-sixth of the population of Hungary) were offered this screening program over 3 years (1988-90). Of the pregnant population, 75.7% (48,312) received MSAFP screening and in 81.0% (51,675), at least one ultrasound scan was performed. In the screened pregnancies, 496 craniospinal, thoraco-abdominal, urogenital and other severe major anomalies occurred; 317 were detected at 18-20 weeks (sensitivity 63.1%; specificity 100.0%; positive predictive value 100.0%). The sensitivity of ultrasound scanning was significantly higher (p < 0.05) than that of the MSAFP screening. (At the time of ultrasound scanning the MSAFP value was known.) In this study, the less serious anomalies such as hydrocele, hypospadias and undescended testicle were not systematically searched for, but the birth prevalences were calculated. The overall mid-trimester prevalence of severe plus less severe major anomalies was 2.26%. The birth prevalences of severe major anomalies were 0.57 (craniospinal), 4.36 (thoracoabdominal and urogenital) and 1.21 (other severe) per 1000. These values were lower than the mid-trimester prevalences which were 2.94, 5.20 and 2.06 per 1000, respectively. The prevalence values at the age of 1 year were also calculated (0.36, 2.21, 0.54 per 1000, respectively). We conclude that our screening program with availability of termination of pregnancy could significantly (p < 0.05) reduce the prevalence of severe major abnormalities at birth. Training programs in cardiac scanning are required.

Abnormalities, Multiple↗

[Screening of congenital anomalies in the mid-trimester of pregnancy. Prospective epidemiologic study. Developmental anomalies].

Authors report about the data of 60,000 pregnant women from three district counties of Eastern-Hungary between 1988 and 1990, on whom both ultrasound and alfa-fetoprotein screenings were performed. They demonstrate the value of this screening for the detection of fetal malformations and for the birth prevalence rate as well. This effective screening-protocol is proposed for a nation-wide application.

Abortion, Spontaneous↗

Influence of gonadotropin (FSH + LH) and thyrotropin (TSH) on the multiplication of Chinese hamster ovary (CHO) cells. Impact of the age of the culture.

CHO cells repeatedly treated with gonadotropin showed peak division rates after their third exposure and a decrease in the mitotic rate after their fourth exposure. Thyrotropin induced a considerable decrease in the mitotic rate following the first exposure, a significant increase after the second and a further decrease following the third and fourth exposures. The pattern did not differ between the two hormones when the cells were exposed further. The age (density of the cell cultures) had an appreciable influence on hormone-provoked changes in the mitotic rate, this differing only in intensity and never in the response following the initial re-exposure.

Animals↗

Impact of serum concentration of the medium and fasting on the imprintability of the insulin receptors of Chang liver cells.

When the cells of the Chang cell line came into interaction with a hormone (insulin) an imprinting-like phenomenon took place. The binding capacity of the receptors strengthened and this feature was transmitted to the descendant generations. The quality of the nutrient medium influenced the development of imprinting, when the cells were maintained in a medium containing 2% serum it was more difficult to evoke imprinting than in case the cells were kept in a medium containing 10% serum. If the cells were cultured kept in Tyrode (physiological) solution for 24 hours the possibility to evoke imprinting was lost. Difference could be observed between the behaviour of receptors in nuclear membrane and that of receptors in the plasma membrane; i.e. changes were more dynamic in the plasma membrane.

Cell Line↗

Impact of combined hormonal pretreatment (insulin+TSH) on the imprinting of hormones administered in combination to Chinese hamster ovary cell culture.

Cultured Chinese hamster ovary (CHO) cells were treated (imprinted) with insulin and with thyrotropin (TSH) related to gonadotropins (FSH+LH). When one week later the treatment was repeated with one of the hormones, considerable differences could be observed in the binding capacity of the cells. In the hormone combination TSH was able to evoke persistent imprinting only to a markedly lesser degree than insulin, meanwhile the imprintatory effect of insulin was of greater extent even on the cell regarded to be unspecific for insulin. Hormone treatment of one hour duration--when investigated immediately after--did not extinct the binding capacity to TSH but enhanced that to insulin. With the deterioration of the conditions of culturing, the enhanced binding capacity disappeared.

Animals↗

[Selective termination of the development of the defective fetus in discordant twin pregnancies].

Selective termination of the affected fetus in twin pregnancies was performed in the second trimester of seven pregnancies. The malformations included anencephaly/exencephaly (2 cases), hydrocephalus (1 case), thoracoabdominopagus of "B" and "C" cotwins (1 case), urethral obstruction sequence (1 case) and hygroma colli (2 cases). Intrauterine intervention on the affected fetus was done by transabdominal intracardial injection of 20% NaCl solution in the 15--24 weeks of gestation. All cases had dichorionic placentation. Unaffected co-twin infants were delivered at term with normal weight in 4 cases. In 2 cases the affected fetus was found in the lower gestational sac and both pregnancies, as well as the triplet pregnancy were lost 1--6 weeks and 3 weeks after the intervention, respectively. In the other cases, neither the mother, nor the survived fetus showed any complications. We believe that using hypertonic saline is lethal for the affected fetus but carries little or no risk either the other fetus or the mother, even if small amounts of the solution might inadvertently enter their circulation.

Abortion, Induced↗

[Experience with chorionic villi sampling].

The authors discuss their experiences from 412 chorion villus samplings, (CVS), which they have done under four and a half years since 1985. They used eight types of instruments in performing their examinations and each instrument proved to be satisfactory in the gaining of chorion villus samples, suitable for further tests. They also discuss the bacteria found most frequently in the vagina on the basis of the examination and culturing of both vaginal and cervical fluid done prior to 151 CVS examinations and the effective method with which ascending infection can be prevented. They discuss a distributional pattern of their results based on the different indications for the CVS examinations, and the outcome of each of the pregnancies after CVS. In 377 cases they did direct karyotyping, in 30 cases DNA examination and in five cases enzyme determination also occurred.

Bacterial Infections↗

Influence of insulin and biogenic amines on the division of Chang liver cells after primary exposure (imprinting) and repeated treatments.

Cells of the Chang liver line responded differently to insulin and histamine exposure and re-exposure after five pretreatments. The mitotic index showed a considerable relative decrease 72 h after the last pretreatment. The response to serotonin did not differ between pretreatment and re-exposure. The effect of insulin and of biogenic amines was positive at the primary exposure and negative 72 h after repeated pretreatments.

Animals↗

[Possibilities of prenatal diagnosis in hemophilia A based on DNA analysis].

Haemophilia-A is the most common bleeding disorder in man, resulting from a deficiency of the coagulant protein, factor VIII. The factor VIII gene is located at Xq28 and the disease is inherited as an X-linked recessive disorder. There is a possibility using DNA probes closely linked to the gene factor VIII to determine the genotype. The availability of factor VIII DNA probes has led to the detection of carrier females and first trimester prenatal diagnosis of haemophilia-A. The authors give a short account on their experiences with four DNA probes. Their studies were carried out in nine families who have affected individuals and plan another pregnancies in the near future. DNA analysis can allow first trimester prenatal diagnosis from chorionic villi taken at 8-10th weeks of gestation. In the case of a male fetus it is possible to determine whether the mutant gene is inherited or not. Till now seven prenatal diagnoses have been performed based on the chorionic DNA.

Chorionic Villi Sampling↗

[Prenatal diagnosis of Hunter's disease].

The authors give a short report about the first-trimester prenatal detection of Hunter's disease (MPS II) inherited as X-linked disorder. There is written about a family having one affected child with Hunter's syndrome. Chorionic villus sample was taken at 10th weeks of gestation in the new pregnancy of the mother. The sex of the fetus was a male determined by DNA analysis. The activity of sulphoiduronate sulphatase was very low. The enzyme activity was also extremely low in the cultured cells from amniotic fluid taken at 16th weeks of gestation. On the basis of these results the pregnancy was terminated at parents's request. The diagnosis of Hunter's disease was confirmed by measuring the enzyme activity of the cultured fibroblasts from the male fetus.

Female↗

Cytoplasmic manifestation of the nuclear membrane's hormone binding capacity during cell division.

Binding of insulin and thyrotropic hormone (TSH) to the nuclear membrane of Chang liver cells was demonstrated by qualitative and quantitative cytofluorimetry, which failed to substantiate a similar binding affinity for BSA. It appears that in the dividing cell the binding structures (receptors) of the nuclear membrane migrate in the cytoplasm together with the chromosomes by the end of the prophase and become reorganized in the nucleus around the telophase. The fluorescence which indicated binding also appeared in the midbody region during division of the two daughter cells. These experimental observations strongly suggest that, after cell division, only part of the nuclear membrane's receptor complement has to be resynthesized in the daughter cells, because the receptor number required by a single cell is conserved in cytoplasmic membrane details of nuclear membrane origin.

Animals↗

Ultrasound diagnosis and screening of fetal cystic fibrosis.

By ultrasound examination of high risk pregnancies for cystic fibrosis in some cases echogenic areas and dilated bowels could be demonstrated. These signs could be detected in 75% of those cases where biochemical assay of the amniotic fluid proved the fetus to be affected with cystic fibrosis. Having got these results authors started to look for these signs during the screening of normal pregnancies. Out of 22 thousand screened pregnancies 28 amniocenteses have been performed because of the ultrasound finding and in 18 cases the low microvillar enzyme activity also predicted cystic fibrosis.

Amniotic Fluid↗

Permanence of the cell-to-cell transmission of insulin induced hormonal imprinting.

When insulin-treated (imprinted) Chang liver cell cultures were mixed with cultures which did not receive insulin treatment the information of imprinting was transmitted to the cultures which were not in direct contact with insulin. The ability of the cells to transmit imprinting was long lasting and could be detected even after four weeks, when it was nearly of the same degree as at the first measurement. Difference was found between the binding capacity of the receptors of the plasma membrane and those of the nuclear membrane.

Animals↗

Impact of pretreatment (imprinting) with insulin on insulin-induced mitotic activity in Chang and CHO cell lines.

Primary interaction with insulin increased the mitotic activity of Chang liver and Chinese hamster ovary (CHO) cells. Re-exposure to insulin accounted for a significant increase of mitoses over the control, but for a considerable decrease thereof relative to the effect of primary exposure. The hormone had a more pronounced effect on its direct target cells (Chang liver cells) than on the CHO cells.

Animals↗