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Biomedical subjects

G Bernaschek

Publications and source records attributed to G Bernaschek.

At least 19 recordsLinked to original sources

High levels of reticulated platelets and thrombopoietin characterize fetal thrombopoiesis.

To characterize fetal thrombopoiesis, we determined plasma thrombopoietin (TPO) and glycocalicin levels, platelet counts and reticulated platelets (RP) of fetuses and compared them with the respective values of their mothers. Percutaneous umbilical vein sampling in abnormal pregnancies revealed twofold higher thrombopoietin levels and 20-fold higher reticulated platelet counts, but lower levels of glycocalicin in fetuses compared with their mothers (P < 0.05). Neither the expression of platelet glycoprotein Ib and IIb on platelets nor the platelet counts were different between mothers and their fetuses. These data indicate enhanced thrombopoiesis and/or increased platelet turnover in fetuses.

Adult↗

Influence of acupuncture on Doppler ultrasound in pregnant women.

OBJECTIVE: To evaluate the influence of acupuncture on the blood flow in the umbilical artery (UA), fetal aorta and uterine artery and on the fetal heart rate using two different acupuncture points (SP-6 (Sanyinjiao) and LI-4 (Hegu)). METHODS: In group A (n = 50), measurements (Doppler ultrasound and fetal heart rate) were performed at term after an uneventful pregnancy (#1) followed by acupuncture treatment using the acupuncture-point SP-6 bilaterally. The treatment time lasted 15 min after which the next measurement (#2) was carried out. The needles were then inserted into the LI-4 acupuncture point for a further 15 min. A third measurement at the end of acupuncture treatment (#3) completed the session. In group B (n = 25), measurements were made before (#1) and after (#4) acupuncture at LI-4 acupuncture points only. RESULTS: In group A, the mean systolic/diastolic (S/D) ratios of UA #1, UA #2 and UA #3 were 2.45, 2.38 and 2.22, respectively (P = 0.0012). The difference in mean S/D ratios between UA #1 and UA #3 as well as that between UA #2 and UA#3 were statistically significant (P = 0.0002 and P = 0.008, respectively). There was no difference between the mean S/D ratios of the uterine artery and between the mean resistance indices of the fetal aorta. In group B, the only significant difference between measurements following acupuncture treatment was in fetal heart rate (139 vs. 143 bpm, P = 0.02). CONCLUSION: Our study indicates a positive influence of acupuncture treatment on umbilical artery waveforms when using a combination of SP-6 (Sanyinjiao) and LI-4 (Hegu) acupuncture points. Acupuncture performed at these sites either individually or in combination does not seem to affect blood flow in the fetal aorta or uterine artery.

Acupuncture Therapy↗

The TSC1 gene product, hamartin, negatively regulates cell proliferation.

Tuberous sclerosis is an autosomal dominant hereditary disease caused by mutations in either the TSC1 or the TSC2 tumor suppressor gene. The TSC1 gene on chromosome 9q34 encodes a 130 kDa protein named hamartin, and the TSC2 gene on chromosome 16p13.3 codes for tuberin, a 200 kDa protein. Here we show that expression of hamartin, assayed by immunoblot analyses, is high in G(0)-arrested cells and hamartin is expressed throughout the entire ongoing cell cycle. An interaction of hamartin and tuberin can be detected in every phase of the cell cycle. Ectopic expression of high levels of hamartin attenuates cellular proliferation. We provide evidence that this effect could depend on a coiled-coil region earlier proposed to be involved in binding of hamartin to tuberin. Further investigations revealed that hamartin affects cell proliferation via deregulation of G(1) phase. Our data have a clear impact on understanding the role of hamartin during development of this disease.

Animals↗

Association of fetal and maternal carboxyhemoglobin levels in normal and Rh-alloimmune pregnancies.

OBJECTIVE: To compare paired antepartum fetal/maternal COHb ratios in whole blood from control and alloimmunized pregnancies and to examine the relationships between fetal and maternal COHb. METHODS: COHb levels were measured in paired fetal and maternal blood samples obtained at cordocentesis in 47 control and 16 Rh-alloimmunized pregnancies. COHb was determined by gas chromatography. Results were analyzed by t-test, regression and analysis of covariance. RESULTS: Although fetal/maternal COHb ratios for control and alloimmunized pregnancies were not statistically significantly different, i.e. 1. 11+/-0.04 and 1.26+/-0.09, respectively (P=0.09), fetal COHb levels were higher in Rh-alloimmunized fetuses (P=0.0002). Fetal COHb levels were also higher than paired maternal levels among the alloimmunized group (P=0.011), but not among the control group (1. 04+/-0.04, P=ns). In univariate regression analysis, fetal and maternal COHb levels were significantly correlated with one another in both control (r=0.52, P=0.0002) and alloimmunized pregnancy groups (r=0.52, P=0.05). Comparison of the slopes of the fetal versus maternal COHb plots for the two groups showed a significant difference (P=0.02), with the alloimmunized group having the steeper slope. CONCLUSION: Differences in the antepartum fetal-maternal COHb relationships in control and alloimmunized groups likely reflect increased endogenous CO production among alloimmunized fetuses as a result of pathologic hemolysis.

Adult↗

Prenatal diagnosis of fetal urinary ascites.

We report on a rare in utero appearance of the rupture of the fetal bladder caused by low urinary tract obstruction with subsequent urinary ascites. The findings on prenatal sonography, postnatal X-ray examinations and postnatal surgical treatment are described and the literature is reviewed.

Adult↗

Transplacental priming of the human immune system with environmental allergens can occur early in gestation.

BACKGROUND: Allergen-specific T cells play an important role in the allergic immune response to various environmental allergens. In vitro studies have shown that T-cell responses to these allergens do occur prenatally. Some allergens (milk proteins) appear to lead more often to fetal T-cell priming than others (house dust mite allergen, ovalbumin, and birch and grass pollen allergens). OBJECTIVE: We sought to determine the window of opportunity for prenatal T-cell priming with inhalant and nutritive allergens. METHODS: The T-cell reactivity of cord blood cells derived through cordocentesis from unborn (n = 62) and term babies (n = 114) in response to inhalant allergens (birch pollen major allergen, recombinant Bet v 1, and timothy grass major allergen, recombinant Phl p 1) was investigated. RESULTS: The results demonstrate that allergen-specific T-cell reactivity is as common in preterm as in term infants (Bet v 1, 8% and 5%, respectively; Phl p 1, 20% and 25%, respectively). CONCLUSIONS: Our data support the hypothesis that differential handling of the allergenic proteins by the feto-placental barrier and possibly by antigen-presenting cells may directly modulate the ensuing T-cell immune response.

Administration, Inhalation↗

Three-dimensional ultrasonographic imaging of fetal tooth buds for characterization of facial clefts.

The purpose of this prospective study was to investigate whether the antenatal characterization of fetal facial clefts can be improved by three-dimensional ultrasonographic visualization of fetal tooth buds. Between January 1996 and June 1998, seventeen consecutive fetuses with facial clefts were examined for fetal maxillary tooth buds in the cleft area using three-dimensional multiplanar reconstruction. It was possible in all cases to classify the clefts either as cleft lip alone or unilateral cleft lip and palate or bilateral cleft lip and palate. Three-dimensional computed tomography and histological jaw sections of three stillborn infants were produced in order to examine the correlation between the sonographic, radiographical and histological findings. The prenatal characterization of the facial clefts by means of a visualization of the tooth buds showed to be accurate postnatally in all cases. The sonographic proof of tooth buds might gain increasing importance as this technique seems to facilitate and improve the prenatal classification of suspected facial clefts.

Adult↗

Unfused amnion and chorion after 14 weeks of gestation: associated fetal structural and chromosomal abnormalities.

OBJECTIVE: To assess possible associations between delayed chorioamniotic fusion after the end of the first trimester and fetal structural and/or chromosomal abnormalities. DESIGN: We prospectively studied 492 fetuses from high-risk pregnancies between 14 and 18 weeks of gestation by transabdominal ultrasonography. Of these, 60 (12%) had unfused amnion and chorion. RESULTS: No additional abnormalities were detected in 28/60 fetuses (47%). Karyotyping was performed in 27/28 cases, and one fetus had trisomy 13 (4%). Ten of 24 fetuses (42%) of this group attending a second mid-trimester scan after 18 weeks of gestation had abnormal sonographic findings not noted at the initial scan. Thirty-two of 60 (53%) fetuses had additional abnormalities at the initial scan: cystic hygroma (n = 12), increased nuchal translucency (n = 10) and other abnormalities (n = 10). Karyotyping revealed aneuploidy in 13 of 28 fetuses (46%) tested: trisomy 21 (n = 5), Turner's syndrome (n = 3), trisomy 18 (n = 3) and trisomy 13 (n = 2). Additional fetal abnormalities were detected only at the second scan after 18 weeks of gestation in three of eight fetuses (38%). CONCLUSIONS: These preliminary data suggest that the sonographic finding of unfused amnion and chorion after 14 weeks of gestation may be associated with fetal structural and/or chromosomal abnormalities.

Amnion↗

The value of echogenic foci ('golfballs') in the fetal heart as a marker of chromosomal abnormalities.

OBJECTIVE: The aim of our study was to determine the significance of antenatally detected hyperechogenic foci in the fetal heart. DESIGN: Prospective study. SUBJECTS AND METHODS: During a 21-month period, 6995 women underwent a sonographic screening investigation. A detailed structural survey was performed on each fetus according to our sonography protocol, including a four-chamber view and an evaluation of the great vessels, as permitted by gestational age. We prospectively identified each fetus with an echogenic intracardiac focus. RESULTS: A total of 150 fetuses with this sonographic finding were identified. The incidence rate was 2.15%. In 114 patients (76%), prenatal karyotyping was performed. The aneuploidy rate was 4.4%. CONCLUSIONS: The echogenic intracardiac focus can be easily diagnosed in most cases. This should prompt an extensive search for other 'soft' markers. The presence of an echogenic intracardiac focus as a single soft marker should raise the question of prenatal karyotyping. It might help in the decision-making regarding invasive prenatal testing in cases with an otherwise low risk for chromosomal abnormality. In cases with other markers for chromosomal abnormality (advanced maternal age, sonographic signs, positive serum marker screening), the presence of an echogenic intracardiac focus should be an additional incentive for a chromosomal examination.

Adolescent↗

Male fetuses are particularly affected by maternal alloimmunization to D antigen.

BACKGROUND: It is hypothesized that male fetuses are more severely affected by fetomaternal alloimmunization to D antigen than female fetuses. STUDY DESIGN AND METHODS: One hundred four consecutive pregnancies with single D+ fetuses (51 males, 53 females) and maternal anti-D titers >16 were analyzed retrospectively. RESULT: Sixty fetuses (58%) received intrauterine transfusions. Male fetuses required more transfusions than females (5.0 vs. 2.0, p = 0.0001). At the initial transfusion, male fetuses had a lower gestational age (24.5 vs. 31.0 weeks, p = 0.0007), cord blood hemoglobin content (6.45 vs. 8.75 g/dL, p = 0.01), and hematocrit (19.8 vs. 26.8%, p = 0.004) than female fetuses. After adjustment for maternal gravidity, parity, and history of affected offspring, the odds ratio for development of hydrops by male fetuses was 13.1 (95% CI 2.69-63.6, p = 0.001). Perinatal mortality was higher in male (18%) fetuses than in female (6%) (adjusted odds ratio for males 3.38; 95% CI 0.59-19.46, p = 0.17). CONCLUSION: Male fetuses are particularly affected by maternal alloimmunization to D and require more intense antepartum surveillance than female fetuses.

Adult↗

[Echogenic intracardiac structures (golf ball phenomenon) as predictors of chromosome anomalies].

UNLABELLED: Small echogenic areas in the fetal heart are known as the golf ball phenomenon. These structures are considered by some to be a marker for chromosomal anomalies. AIM: To prospectively study the relationship of echogenic intracardiac structures and chromosomal aberrations. METHODS: Over a 15 month period (6/96-9/97) 4500 unselected fetuses between 16-31 weeks were screened for malformations; in each case echogenic intracardiac structures were sought. RESULTS: In 77 cases (1.17%) single or multiple echogenic punctate intracardiac structures could be diagnosed. In 60 fetuses (78%) chromosome analysis was performed. Two (3.3%) had chromosomal abnormalities--trisomy 21 and 45.XO/46.XX. CONCLUSION: The golf ball phenomenon appears to be a normal variation in the development of the papillary muscle. This sign is usually easily to identify and if present, should lead to a more detailed screening for anomalies. In the case of other sonographic abnormalities, with advanced maternal age or with a positive triple test, a chromosomal analysis should be performed.

Adult↗

Isolated Dandy-Walker malformation: prenatal diagnosis in two consecutive pregnancies.

We report a family with recurrent Dandy-Walker malformation (DWM). The first offspring was found prenatally to have isolated DWM at 30 weeks' gestation. Ultrasonography at 19 weeks' gestation in the subsequent pregnancy revealed isolated DWM in both dizygotic twins. Chromosome analysis was normal in all three infants, and autopsy confirmed that no other congenital abnormalities were present. Evidence suggests that rare families transmit the disorder in an autosomal or X-linked recessive pattern, with a high recurrence risk.

Adult↗

Antepartum fetal and maternal carboxyhemoglobin and cotinine levels among cigarette smokers.

The objective of this study was to examine the association of carboxyhemoglobin (COHb) and plasma cotinine levels among pregnant women who smoke cigarettes and their fetuses. Fifteen pregnant women who smoked and their fetuses undergoing cordocentesis had blood samples analysed simultaneously for COHb and cotinine. Linear regression was used to test for associations among study variables. Significant maternal-fetal associations were observed both with COHb (r = 0.72, p = 0.003) and with cotinine (r = 0.96, p = 0.003). Maternal cotinine levels were correlated with maternal and fetal COHb levels (r = 0.96, p = 0.003; r = 0.99, p = 0.0003, respectively). Fetal cotinine levels were correlated with COHb in maternal and in fetal blood (r = 0.81, p = 0.0003; r = 0.88, p<0.0001, respectively). The strong direct associations of maternal and fetal levels of COHb and cotinine indicate that maternal COHb and cotinine measurements may be interpreted as surrogates of fetal COHb levels. However, the specificity, ex vivo stability and ease of measurement of cotinine offer advantages over using COHb in quantifying fetal CO exposure following maternal cigarette smoking.

Adult↗

Ultrasound evaluation of fetal spine length between 14 and 24 weeks of gestation.

The objective of our study was to establish a nomogram of fetal spine length in the second trimester of pregnancy by using two and three-dimensional ultrasound. Fetal spine length was measured prospectively by means of transabdominal ultrasonography in 114 normal singleton pregnancies between 14 and 24 weeks of gestation. Regression analyses were performed on spine length, gestational age, biparietal diameter and femur length. Supplementary three-dimensional ultrasound to assess fetal spine length was performed in 75 cases. Fetal spine length, as a function of gestational age, was expressed by the following regression equation: spine length (mm) = -47.2 + 7.16 x gestational age (weeks), with a Pearson correlation coefficient of R(2)=0.956. The results of the measurements revealed no difference between two and three-dimensional ultrasound. Our study defines the normal limits of fetal spinal length in the second trimester of pregnancy and demonstrates a high correlation between spinal length, gestational age, biparietal diameter and femur length. However, there are still too few prenatal research data to say whether and to what extent an assessment of fetal spine length at this stage of pregnancy can be used for prenatal diagnosis of congenital syndromes, which, among other manifestations, are marked by fetal spine lengthening or shortening.

Female↗

A role of the tuberous sclerosis gene-2 product during neuronal differentiation.

Tuberous sclerosis is an autosomal dominant disorder. Besides the development of benign growths (hamartomas) in different tissues, one hallmark of this disease is the presence of highly epileptogenic dysplastic lesions in the cerebral cortex (tubers) composed of abnormal shaped neurones. Patients often show evidence of severe mental retardation. Linkage analysis revealed two disease-determining genes on chromosome 9 and chromosome 16. The TSC2 gene on chromosome 16 encodes a 1784-amino acid putative tumour suppressor protein, tuberin, that functions as a GTPase-activating protein. Here we show that tuberin expression is upregulated upon induction of neuronal differentiation in the neuroblastoma cell lines SK-N-SH and LAN-1. This upregulation occurs at post-transcriptional level and is independent of the proliferation status. TSC2 expression is unaffected during differentiation of C2C12 myoblasts into myotubes and of F9 embryonal carcinoma cells into cells resembling parietal endoderm. Antisense inhibition of tuberin expression in SK-N-SH or LAN-1 cells inhibits neuronal differentiation, but does not affect the differentiation of F9 cells. Ectopic overexpression of TSC2 not only reverts the antisense-associated phenotype but furthermore accelerates the neuronal differentiation process. Our data show for the first time that tuberin plays a critical role in neuronal differentiation. Such role is consistent with the phenotype of tuberous sclerosis patients, who inherit one defective TSC2 allele, and frequently lose the remaining normal allele in many of the tubers/hamartomas which develop in the central nervous system of these patients.

Animals↗

Three-dimensional ultrasound evaluation of fetal tooth germs.

OBJECTIVE: A total of 126 genetic syndromes are associated with oligodontia or anodontia. The most frequent of these are ectodermal dysplasias, all types of facial cleft and Down's syndrome. With the advent of three-dimensional ultrasonography, accurate assessment of many fetal abnormalities has become possible. The objective of this study was to determine the effectiveness of three-dimensional ultrasonography in the visualization of fetal tooth germs. DESIGN: We examined 45 women with singleton pregnancies between 16 and 36 gestational weeks who were undergoing routine ultrasound check-ups for fetal tooth germs with conventional two-dimensional ultrasonography, followed by three-dimensional ultrasonography using multiplanar reconstruction. RESULTS: In the 45 fetuses studied, fetal tooth germs were visualized at the first attempt in 36 cases (80%). In the group of fetuses aged between 19 and 36 weeks of gestation, the overall detection rate in both jaws was at least 86% for three-dimensional ultrasonography, compared to at least 56% for two-dimensional ultrasonography. CONCLUSIONS: Three-dimensional ultrasonography was clearly superior to conventional ultrasonography in the visualization and evaluation of fetal tooth germs. Three-dimensional ultrasonography therefore has a potential for enhanced visualization of fetal tooth germs and may aid in the antenatal detection of syndromes associated with oligodontia or anodontia.

Cleft Lip↗