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Biomedical subjects

R Faber

Publications and source records attributed to R Faber.

At least 19 recordsLinked to original sources
PubMed2001

Gestational regulation of the gene expression of C-type natriuretic peptide in mouse reproductive and embryonic tissue.

C-Type natriuretic peptide (CNP) is a vasoactive hormone and the endothelial component of the natriuretic peptide system. We examined the expression of CNP in mouse reproductive organs and embryos at different stages of gestation. Pregnant mice were killed and embryos were dissected on gestational days 9.5, 12.5, 15.5, 18.5 postconceptionem (pc) and at term. Nonpregnant mice were used as controls. Total RNA was isolated from placenta, ovaries, myometrium and from head and trunk of embryos and neonates. CNP-mRNA was quantified by ribonuclease-protection assay (RPA). Uterine CNP-mRNA concentrations increase during pregnancy up to the sevenfold concentration, whereas in the ovaries these levels decrease to 10% compared to nonpregnant controls. In the placenta, a peak of CNP expression has been observed around day 15.5 pc, whereby placenta showed the strongest CNP signals. CNP-mRNA concentrations in embryos are gestational age-dependent with a high level at day 9.5 pc in head and trunk. These results indicate that CNP has a regulatory function in pregnancy and embryonic development.

Animals↗
PubMed2001

Dual natriuretic peptide response to volume load in the fetal circulation.

OBJECTIVE: To measure atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in control fetuses and fetuses with Rhesus isoimmunisation before and after intravascular transfusion. The current study was designed to investigate the response of ANP and BNP to cardiac short-term and long-term volume load in the human fetus. METHODS: Fetal blood samples were collected from 18 human fetuses (nine controls, nine anemic fetuses with Rhesus isoimmunisation before and after intravascular transfusion). Fetal ANP and BNP concentrations were measured and compared to maternal plasma levels. RESULTS: Both ANP and BNP were significantly higher in fetal blood compared to the mothers. Fetuses with Rhesus isoimmunisation, characterized by long-term cardiac overload, showed significantly elevated ANP but not BNP concentration compared to the fetal controls (ANP: 80.8+/-16.6 vs. 31.6+/-7.7 pg/ml, P<0.05). However, short-term volume load due to intravascular transfusion leads to a significant increase in the fetal BNP- but not ANP-plasma level (BNP: 112.9+/-14.1 vs. 64.8+/-6.6 pg/ml, P<0.05). CONCLUSION: ANP and BNP respond differently to cardiac short- and long-term volume load in the fetal circulation. Therefore, the data suggest that in the fetus, similar to adults, ANP and BNP constitute a dual natriuretic peptide system responsive to changes in cardiac filling pressure.

Analysis of Variance↗
PubMed2001

Detection of cervical immunoglobulin A in normal pregnancy.

The aim of our study was to evaluate a feasible method to quantify the immunoglobulin A concentration in the cervical mucus of women with a normal singleton pregnancy. In 60 immunologic healthy pregnant women cervical mucus samples were taken at a random time in pregnancy using an absorbing cylindrical cotton-swab stick. In this cervical mucus immunoglobulin A concentration was measured by radial immunodiffusion. A vaginal bacterial swab was taken from each woman. Concentration of immunoglobulins in maternal serum was estimated. There was no statistically significant difference of cervical immunoglobulin A concentration between the investigated groups (p = 0.952): 18-24 gestational weeks (gw): 52.8 (6.6-258.4) mg/l; 25-29 gw: 89.3 (4.8-193.8) mg/l; 30-34 gw: 55 (1.4-326) mg/l; 35-40 gw: 59.2 (4-400.9) mg/l. Women with a normal vaginal flora showed a significantly higher cervical immunoglobulin A concentration than those with a pathological colonization: 92.2 (6.6-400.9) mg/l vs. 42.5 (1.4-326) mg/l (p < 0.05). The serum levels of immunoglobulins A, A1, A2, M and G do not correlate to cervical immunoglobulin A levels nor to gestational age. In normal pregnancy, cervical immunoglobulin A concentration does not change with advancing gestational age, but a pathological vaginal colonization seems to be associated with decreased immunoglobulin A levels.

Adolescent↗
PubMed2000

Persistent fetal rubella vaccine virus infection following inadvertent vaccination during early pregnancy.

Inadvertent immunisation of seronegative women with RA27/3 rubella virus live-attenuated vaccine several weeks before and after conception is described. Whereas in 5 cases the vaccine virus was not transmitted vertically, in 1 case vaccination led to the development of persistent fetal infection with prolonged virus shedding for more than 8 months. Sequence analysis carried out on isolates from amniotic fluid, from cord blood leukocytes as well as from infantile urine confirmed an infection by the vaccine strain. At birth, the newborn infant exhibited none of the symptoms compatible with the congenital rubella syndrome and signs indicative for development of late onset disease are not apparent. This observation constitutes the first unequivocal documented case of rubella vaccine virus related to persistent fetal infection.

Adult↗
PubMed2000

Greenberg dysplasia: first reported case with additional non-skeletal malformations and without consanguinity.

In 1988 Greenberg et al. reported an association of fetal hydrops with irregular calcification and moth-eaten skeletal dysplasia. Here, we report on the first case of this disorder accompanied by additional malformations (omphalocele, intestinal malrotation, disturbed fingernails and toes, hypolobated lungs) in a German couple without consanguinity (karyotype 46,XY). Sonograpically, the fetus was characterised by tetraphokomelia, severe generalised hydrops, pulmonal hypoplasia and hepato-splenomegaly. Greenberg dysplasia should be considered in differential diagnosis in cases with severe fetal hydrops and phokomelia on antenatal sonography.

Abnormalities, Multiple↗
PubMed2000

Prenatal diagnosis of del(15)(q26.1) and del(18)(q21.3) due to an unbalanced de novo translocation: ultrasound, molecular cytogenetic and autopsy findings.

A case of partial deletion of the distal parts of chromosomes 15 and 18 [(15)(q26.1)(18)(q21.3)] due to a de novo translocation is reported. Cordocentesis and fetal karyotyping was done because of severe oligohydramnios and bilateral absence of kidneys. Renal defects are a frequent finding in fetuses with different chromosomal anomalies; this particular chromosomal rearrangement however has not been reported yet in a fetus with bilateral renal agenesis. FISH was performed for detailed clarification of the chromosomal anomaly. Prenatal karyotyping appears to be important in fetuses with renal agenesis.

Adult↗
PubMed2000

Baroreflex sensitivity, heart rate, and blood pressure variability in normal pregnancy.

Heart rate variability is a relevant predictor of cardiovascular risk in humans. However, to use heart and blood pressure (BP) variability or baroreflex sensitivity as markers for hypertensive pregnancy disorders, it is first necessary to describe these parameters in normal pregnancy. To accommodate the complexities of autonomic cardiovascular control we added parameter domains of nonlinear dynamics to conventional linear methods of time and frequency domains. The BP of 27 women with normal pregnancy and 14 nonpregnant women were monitored at a high resolution (200 Hz sampling frequency) using a Portapres for 30 min. The pregnant women were divided into groups of 32 or less or greater than 32 weeks of gestation. Pregnant and nonpregnant women were classified into subclasses of maternal age of less than 28 or 28 or more years. Except for two single parameter domains, we found no significant differences in heart rate and BP variability for pregnant women with different gestational age or different maternal age. Moreover, no significant differences in spontaneous baroreflex sensitivity could be found between pregnant women regardless of either their age or gestational age. In contrast, all measures of nonlinear dynamics of heart rate variability as well as all parameter domains of spontaneous baroreflex sensitivity showed significant changes between pregnant and nonpregnant women, whereas BP variability did not differ between those groups. This complex assessment of autonomic cardiovascular regulation has shown that the parameters tested are stable in the second half of normal pregnancy, and might have the potential to be excellent indicators of pathophysiologic conditions.

Adult↗
PubMed2000

Detection of nucleic acid sequences from bacterial species with molecular genetic methods.

While blood products become more safe in terms of viral contamination, the risk of transfusion-related bacterial infection has re-emerged to one of the major hazards in transfusion medicine. In recent prospective studies the rate of contaminated platelets ranged from 0.04 to 0.5%, and a rate of transfusion reactions between 0.007% and 0.046%. It is generally agreed that most of the organisms isolated from donated blood originate from the normal skin flora or from the environment. As it is unlikely that antiseptic methods can achieve absolute sterilization of the skin before venepuncture, blood banks have to rely on laboratory tests to detect contaminated blood products before release. But most of the currently available methods detecting bacterial contaminations do not have the potential to be sensitive and fast enough for a routine contamination screening in transfusion services. Here we present two alternative strategies based on molecular genetic techniques (Real-Time-PCR and Haystack processing) that detect or semi-quantify bacterial rRNA gene sequences for the majority of bacterial species. In addition we discuss some aspects on target selection, routine preparation and residual 16S-rDNA-contamination of enzymes.

Bacteria↗
PubMed2000

Detection of C-type natriuretic peptide in fetal circulation.

C-type natriuretic peptide (CNP) belongs to the natriuretic peptide family that plays an important role in the control of blood pressure, renal function and volume homeostasis. In contrast to the atrial natriuretic peptide and brain natriuretic peptide, CNP acts in an autocrine/paracrine fashion and is considered to be the endothelial component of the natriuretic peptide system. CNP has a high expression and tissue-specific regulation in reproductive organs. Using a radio-immunoassy for CNP-22 we measured for the first time CNP in fetal blood. Samples were taken by cordocentesis in a group of fetuses with rhesus isoimmunisation (10.74 +/- 2.81 pg/ml), fetuses with rhesus isoimmunisation after intravascular transfusion (10.03 +/- 4.01 pg/ml) and a group with structural anomalies (12.9 +/- 5.67 pg/ml). A group of healthy fetuses was used as controls (11.64 +/- 4.32 pg/ml). In contrast to ANP, the fetal CNP-plasma concentrations remain stable in the investigated fetal diseases and after volume load during intravascular transfusion. Moreover, fetal CNP-plasma levels are higher than previously measured maternal concentrations in normal pregnancies. Therefore, the fetus expresses CNP independently of the maternal circulation.

Blood Transfusion, Intrauterine↗
PubMed2000

Postnatal intestinal disturbances in small-for-gestational-age premature infants after prenatal haemodynamic disturbances.

Uteroplacental insufficiency leads to fetal growth retardation, which is a major cause of perinatal and postnatal morbidity. In the present study we investigated the relationship between prenatal haemodynamic disturbances and postnatal intestinal perfusion and gastrointestinal function in small-for-gestational-age neonates. Prospectively, 114 preterm neonates with a birthweight below 1500 g were assigned to one of two groups according to their prenatal Doppler sonographic measurements: neonates with or without prenatal haemodynamic disturbances. We defined a pathological fetal perfusion by a pulsatility index of uterine arteries, umbilical artery and fetal thoracic aorta above the 90th percentile and by a pulsatility index of middle cerebral artery below the 10th percentile of a normal group. We compared the postnatal respiratory and intestinal adaptation in both groups as well as the blood flow velocity waveforms of the superior mesenteric artery in all neonates. Postnatally, all 36 neonates with prenatal haemodynamic disturbances were classified to be small for gestational age. Thirty-one of these neonates developed abdominal problems with delayed meconium passage, abdominal distension, bilious vomiting and a delay in tolerating in enteral feeding within the first days of life. Six of them needed surgical intervention, but none of these infants revealed typical signs of necrotizing enterocolitis. In contrast, all neonates after normal prenatal perfusion were classified to be appropriate for gestational age. Only 19 of 78 neonates of this group showed signs of intestinal disturbances postnatally. By Doppler sonographic investigations we found significant lower systolic, mean and end-diastolic flow velocities and higher pulsatility indices of the superior mesenteric artery in neonates with prenatal haemodynamic disturbances. This may occur as a result of postnatal persistent redistribution of regional blood flow and results in gastrointestinal problems and may adversely affect gut motility.

Blood Flow Velocity↗
PubMed1999

Prenatal detection of a giant bilateral thoracic vascular lesion: prognostic evaluation and genetic aspects.

We describe a giant bilateral vascular mass in the skin of the chest diagnosed by ultrasound investigation in a fetus of 20 gestational weeks. Ultrasound and colour Doppler investigations detected no signs of early congestive heart failure but rapid and excessive enlargement of the vascular mass. Indications of increased fetal blood volume were found. The fetus had additional minor anomalies. Early in utero manifestation suggests a severe vascular malformation.

Amniocentesis↗
PubMed1999

C-type natriuretic peptide levels in women with gestational hypertension and preeclampsia.

OBJECTIVE: To measure plasma levels of C-type natriuretic peptide in women with normal pregnancies and those complicated by gestational hypertension and preeclampsia. METHODS: We collected venous plasma samples from 20 women with normal pregnancies, 15 with gestational hypertension, and nine with preeclampsia. Gestational ages ranged from 26-39 weeks. We measured C-type natriuretic peptide concentrations by radioimmunoassay. Statistical comparisons were made by one-way analysis of variance and Tukey test. RESULTS: The mean plasma concentration of C-type natriuretic peptide in the women with normal pregnancy was 7.1 +/-2.5 pg/mL, in those with gestational hypertension 9.6+/-4.2 pg/mL, and in those with preeclampsia 8.1+/-2.4 pg/mL. There were no statistically significant differences between groups. The statistical power to detect a difference of 3 pg/mL at the 5% significance level was 78% for the group with gestational hypertension and 64% for the preeclamptic group. CONCLUSION: Our results suggest that C-type natriuretic peptide plasma levels are not significantly different in normal pregnancies and those complicated by gestational hypertension or preeclampsia. In hypertensive pregnancy disorders, C-type natriuretic peptide showed a distinct course compared with atrial natriuretic peptide and brain natriuretic peptide.

Adult↗
PubMed1999

Congenital hernia of the abdominal wall: a differential diagnosis of fetal abdominal wall defects.

A 28-year-old woman was referred at 33 weeks of gestation with suspected fetal intestinal atresia. Sonography showed a large extra-abdominal mass on the right of the normal umbilical cord insertion. Following Cesarean section at 36 weeks and immediate surgical treatment, the malformation was not definable either as an omphalocele or as gastroschisis. This reported case involves a previously undocumented malformation of the fetal abdominal wall described as a 'hernia' of the fetal abdominal wall.

Abdominal Muscles↗
PubMed1999

Expression of low density lipoprotein receptor messenger ribonucleic acid in placentas from pregnancies with intrauterine growth retardation.

The low density lipoprotein receptor plays an important role in the uptake of maternal plasma lipoproteins for placental steroid metabolism. Using an RNase protection assay, the expression of low density lipoprotein receptor mRNA was measured in human placentas from pregnancies in the second and third trimester and from pregnancies with intrauterine growth retardation. Pregnancies complicated by intrauterine growth retardation showed a significantly higher expression (1.28), compared with the term and preterm pregnancies (P < 0.05). The increased low density lipoprotein receptor expression in placentas from pregnancies with intrauterine growth retardation could be a compensatory mechanism for the lower circulating low density lipoprotein concentrations in women with intrauterine growth retardation.

Female↗
PubMed1998

DNA analysis for phospholipase A2 coding sequences of Mycoplasma hominis isolated from women with a normal pregnancy and women with a pregnancy complicated by preterm labour.

A possible cause of preterm labour is an increased synthesis of prostaglandins by a phospholipase A2 (PLA2) activity. PLA2 activity has been detected in Mycoplasma hominis. The aim of this study was to test whether chromosomal DNA of M. hominis contains sequences coding for PLA2. M. hominis was cultured in specimens from 5 women with normal pregnancy and 4 in preterm labour. Using sequence alignment, primer pairs for the active part of PLA2 of different species were designed for PCR analysis. No sequences coding for PLA2 could be amplified. Whatever its role in preterm labour, M. hominis is not involved in causing an increase of prostaglandin synthesis.

DNA, Bacterial↗
PubMed1998

Absence of phospholipase A2 activity in genital Mycoplasma hominis.

The clinical relevance of vaginal colonization with Mycoplasma hominis (M hominis) as a cause of prematurity is doubtful. One of the possible pathways which could explain the role of M hominis in the induction of preterm labour is an increased synthesis of prostaglandins by a phospholipase A2 activity. The aim of this study was to prove whether M hominis secrets proteins with a PLA2 activity and to test whether there are strain differences in the enzyme activity between M hominis isolated from women with normal pregnancy and those with preterm labour. Using specific radio-immunoassay we could not measure any PLA2 activity in the supernatant of all investigated M hominis strains. We exclude the mechanism of induction of preterm labour by M hominis via an increased prostaglandin synthesis. Our findings make a relation between vaginal colonization with M hominis and prematurity unlikely.

Female↗