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Biomedical subjects

C Rodeck

Publications and source records attributed to C Rodeck.

At least 37 records · Page 2Linked to original sources
PubMed2000

The misoprostol third stage of labour study: a randomised controlled comparison between orally administered misoprostol and standard management.

OBJECTIVE: To compare misoprostol with standard oxytocic regimens in the prevention of postpartum haemorrhage. DESIGN: Randomised controlled trial. SETTING: Obstetric unit in a large teaching hospital. METHODS: One thousand women randomised to 500 microg misoprostol given orally or to standard oxytocic regimens of oxytocin, oxytocin with ergometrine, or ergometrine. MAIN OUTCOME MEASURES: Incidence of postpartum haemorrhage and the incidence and severity of side effects. RESULTS: Postpartum haemorrhage occurred in 12% of women given misoprostol and in 11% of women given standard oxytocic drugs (relative risk (RR) 1.10, 95% confidence interval (CI) 0.79, 1.55). Blood loss of 1000 mL or more occurred in 2% of women in each group. Nausea, headache, dizziness and tiredness were less frequent with misoprostol (RR (95% CI) 0.71 (0.59, 0.84); 0.53 (0.38, 0.74); 0.73 (0.61, 0.87) and 0.88 (0.83, 0.94) respectively). The main side effects of misoprostol were shivering (RR 1.95, 95% CI 1.69, 2.25) and a rise in temperature (difference in mean rise 0.34 degrees C, 95% CI 0.26, 0.42). CONCLUSION: Oral misoprostol for the prevention of postpartum haemorrhage was comparable to standard oxytocics. Many side effects were less common with misoprostol but shivering and pyrexia were more common. Larger randomised trials are needed before establishing the equivalence between misoprostol and standard oxytocic drugs in the prevention of postpartum haemorrhage.

Administration, Oral↗
PubMed2000

Effect of NO, phenylephrine, and hypoxemia on ductus venosus diameter in fetal sheep.

To study the regulation of the ductus venosus (DV) inlet in vivo, we measured the effect of vasoactive substances and hypoxemia on its diameter in nine fetal sheep in utero at 0.9 gestation under ketamine-diazepam anesthesia. Catheters were inserted into an umbilical vein and a fetal common carotid artery, and a flowmeter was placed around the umbilical veins. Ultrasound measurements of the diameter of the fetal DV during normoxic baseline conditions [fetal arterial PO(2) (PaO(2)) 24 mmHg] were compared with measurements during infusion of sodium nitroprusside (SNP; 1.3, 2.6, and 6.5 microg. kg(-1). min(-1)) or the alpha(1)-adrenergic agonist phenylephrine (6.5 microg. kg(-1). min(-1)) into the umbilical vein or during hypoxemia (fetal Pa(O(2)) reduced to 10 mmHg). SNP increased the DV inlet diameter by 23%, but phenylephrine had no effect. Hypoxemia caused a 61% increase of the inlet diameter and a distension of the entire vessel. We conclude that the DV inlet is tonically constricted, because nitric oxide dilates it but an alpha(1)-adrenergic agonist does not potentiate constriction. Hypoxemia causes a marked distension of the entire DV.

Adrenergic alpha-Agonists↗
PubMed2000

Serum screening for Down syndrome and adverse pregnancy outcomes: a case-controlled study.

The relationship between adverse perinatal outcomes in women with false positive biochemical screening test for Down syndrome was investigated in a retrospective case-controlled study. A cohort of 4000 women who booked for routine antenatal care and opted for biochemical screening over a 22 month period was obtained. The pregnancy outcome data of 272 women with a false positive screening test for Down syndrome (risk >1 in 250) at 15-18 weeks of gestation (study group) were compared with data from 272 age and gestation matched controls with a negative Down syndrome screening test from the same population. The frequency of normal and adverse perinatal outcomes, including pre-eclampsia, isolated intrauterine growth restriction, spontaneous preterm labour and stillbirth was recorded. The incidence of adverse pregnancy outcomes was 11.9% in the study group and 8.6% in the control group. The estimated odds ratio of an abnormal outcome in the study group was 1.41 (95% CI-0.790, 2.55). The observed difference between proportion was 0.0324 (95% CI-0.022, 0.083; p=0.40). These data identify no evidence for a strong association between a false positive Down syndrome screening test result and subsequent adverse perinatal outcomes in the general population.

Case-Control Studies↗
PubMed1999

Rapid detection of chromosomes X and Y aneuploidies by quantitative fluorescent PCR.

Quantitative fluorescent polymerase chain reaction (QF-PCR) assays and small tandem repeat (STR) markers have been successfully employed for the rapid detection of major numerical aneuploidies affecting human autosomes. So far, the analysis of chromosomes X and Y disorders has been hampered by the rarity of highly polymorphic markers which could distinguish normal female homozygous PCR patterns from those seen in patients with Turner's syndrome. A new marker (X22) of the X/Y chromosomes has been identified which maps in the Xq/Yq pseudoautosomal region PAR2; used together with the HPRT it allows the rapid diagnosis of numerical aneuploidies of the sex chromosomes. Blood samples from normal male and female subjects and from patients with X and Y chromosome disorders (45,X and 47, XXY) have been tested by QF-PCR with the X22 polymorphic pentanucleotide (12 alleles) together with the HPRT and P39 markers. The samples were also tested by multiplex QF-PCR with STRs specific for chromosomes 21,18,13 and amelogenin (AMXY). Tested by QF-PCR, all samples from normal females were heterozygous for either the X22 or the HPRT marker with fluorescent peak ratios near 1:1, thus allowing a correct, rapid diagnosis of their chromosome complement. Turner's patients (45,X) showed only one X22 and one HPRT fluorescent peak, thus documenting the presence of a single X chromosome. Turner's patients with mosaicism showed a major fluorescent peak for the X22 and HPRT markers and a minor peak revealing the presence of a second minor population of cells. Two 47, XXY cases could also be diagnosed. Multiplex analyses can be performed using simultaneously STR markers for chromosomes 21,18,13 X and Y. The diagnostic value of a third X-linked marker (P39) was also investigated. These results suggest that rapid diagnosis of major numerical anomalies of the X and Y chromosomes can be performed using QF-PCR with a new highly polymorphic X-linked marker, X22, which maps in the Xq/Yq pseudoautosomal region PAR 2. Multiplex QF-PCR tests-using the X22 STR in association with HPRT and, in rare cases, a third P39 marker-allow the rapid diagnosis of major aneuploidies affecting chromosomes 21, 18, 13, X and Y. The X22 marker can also be employed for the detection of fetal cells present in maternal peripheral blood or the endocervical canal.

Aneuploidy↗
PubMed1999

Maternal tobacco exposure and cotinine levels in fetal fluids in the first half of pregnancy.

OBJECTIVE: To evaluate the distribution of cotinine in fetal fluids and serum during the first half of pregnancy, and compare the fetal and maternal cotinine levels in passive and active smokers. METHODS: Maternal smoking status was determined by questionnaire in 85 pregnant women requesting abortion for psychosocial reasons between 7 and 17 weeks' gestation. Coelomic and amniotic fluid samples were collected between 7 and 11 weeks and fetal blood and amniotic fluid between 11 and 17 weeks. Cotinine levels were measured by radioimmunoassay. RESULTS: Women classified themselves as nonsmokers in 40 cases, passive smokers in 19 cases, and voluntary smokers in 26 cases. Five nonsmokers, 16 passive smokers, and all smokers had cotinine levels above the detection limit of the assay. Cotinine was invariably found in coelomic, amniotic, and fetal serum when maternal serum and urine cotinine levels exceeded 25 and 250 ng/mL, respectively. Higher cotinine levels were found in fetal fluids and serum than in maternal serum. Positive linear correlations were found between maternal urine and amniotic fluid cotinine concentrations (r = .75), between maternal urine cotinine concentration and number of cigarettes smoked per day (r = .66), and between maternal and fetal serum cotinine concentrations (r = .97). CONCLUSION: Cotinine accumulates in the fetal compartments as early as 7 weeks' gestation in both active and passive smokers. Women should be advised to give up smoking from conception and avoid environmental tobacco smoke exposure.

Amniotic Fluid↗
PubMed1999

Transcervical cells and the prenatal diagnosis of haemoglobin (Hb) mutations.

Prenatal diagnoses of haemoglobin (Hb) mutations were performed using transcervical cells, retrieved by aspiration from the endocervical canal of ten selected pregnant women at about 10 weeks of gestation, prior to chorionic villus sampling (CVS). Both parents were carriers of haemoglobinopathies (thalassaemia or HbS). Clumps of fetal cells were isolated by micromanipulation under an inverted microscope and aliquots of the extracted DNA tested separately for the presence of paternally derived chromosome markers and Hb mutations by quantitative fluorescent polymerase chain reaction (PCR). The correct prenatal diagnosis of Hb diseases, using selected single clumps of trophoblastic cellular elements free of maternal contaminating cells, was achieved in six out of ten cases.

Anemia, Sickle Cell↗
PubMed1999

Successful expression of beta-galactosidase and factor IX transgenes in fetal and neonatal sheep after ultrasound-guided percutaneous adenovirus vector administration into the umbilical vein.

In utero somatic gene therapy in the later stages of pregnancy may allow targeting of organ systems which are difficult to reach later in life and to prevent the development of tissue damage otherwise caused by the early onset of inherited diseases. We report here on the percutaneous delivery of two adenoviral vectors, containing the beta-galactosidase reporter gene and the human Factor IX gene respectively, to the fetal liver and circulation by ultrasound-guided umbilical vein puncture similar to procedures used in human pregnancy. Vector spread, as detected by PCR analysis for the beta-galactosidase encoding vector, was found in almost all fetal and neonatal organs and in the maternal liver. Expression of the beta-galactosidase transgene was detected in many fetal tissues by RT-PCR. High beta-galactosidase production was shown by immuno-histochemistry predominantly in the liver, where about 30percent of the hepatocytes stained positive, and in the adrenal cortex. Production of factor IX was determined by ELISA in the plasma of treated fetuses and newborn lambs and reached at birth up to 80percent of the normal human plasma concentration. This demonstrates a very hopeful proof of principle for the development of prenatal treatment of many genetic diseases but also requires more detailed investigations with respect to the observed systemic spread of the vector.

Adenoviridae↗
PubMed1999

National Confidential Enquiry into counselling for genetic disorders by non-geneticists: general recommendations and specific standards for improving care.

OBJECTIVES: To assess genetic counselling by non-geneticists and to improve clinical practice. DESIGN: National retrospective review of casenotes. SETTING: Antenatal, paediatric, medical, and surgical units. SAMPLE: 1293 genetic events were identified, involving potentially avoidable cases of Down's syndrome, neural tube defect, cystic fibrosis, beta thalassaemia major and late onset medullary carcinoma of the thyroid (multiple endocrine neoplasia). Notes were available for review in 888 (69%) of these cases. OUTCOMES: Documented counselling, offers of relevant genetic screening and prenatal diagnosis. RESULTS: Clinical audit was frustrated by poor quality hospital records lacking evidence of counselling. Non-geneticist clinicians concentrate on the management of disease, and may overlook the need for counselling and recording data which patients will later need for decisions about reproduction or disease prevention. Counselling, screening and prenatal diagnosis were sometimes impossible because of late booking in pregnancy, or because of delayed diagnosis of an earlier affected child with cystic fibrosis. There are marked regional inequalities of access to genetic services, particularly for minority ethnic groups with increased risks of thalassaemia. Although patients were selected for this enquiry because they had known high risks of genetic disorders, on average less than half were referred to medical geneticists. General recommendations relevant for improvement of care for patients and families with medical genetic needs and those specific for each disorder are given. CONCLUSIONS: Assessment of the quality of genetic care becomes increasingly important as genetic counselling spreads beyond the narrow confines of specialist genetic services. Even though the events studied in this enquiry largely occurred between 1991 and 1995, there is little reason to believe that clinicians in general have become markedly better trained in medical genetics. The General Medical Council and Medical Royal Colleges should urgently consider the need for a national policy for improving undergraduate and postgraduate medical, nursing and midwifery education in genetics. Commissioners of clinical services should require that genetic management be at least as well-documented as surgical operations, drug records and informed consent, perhaps by using a nationally agreed pro-forma for prenatal diagnosis. Regular audit of counselling provided by non-geneticists is necessary to confirm that clinical improvements are occurring and standards are being met. The Confidential Enquiry provides data for a systematic approach to clinical governance of genetics in all specialities. This sets the scene for multi-speciality NHS genetic services capable of giving patients greater consistency both in access and in quality.

Clinical Competence↗
PubMed1998

Free amino acid distribution inside the first trimester human gestational sac.

The trophoblast functions of nutrient transport and protein synthesis generate high concentrations of amino acids in the placenta and in fetal blood during the second half of pregnancy, but little is known about these metabolic processes in embryonic and early fetal periods. The aim of this study is to compare the distribution of amino acids inside the first trimester gestational sac. Free amino acid concentrations were measured in homogenates of placental villi, in samples of coelomic and amniotic fluid, and in the maternal serum from 17 normal pregnancies between 7 and 11 weeks of gestation. Significant positive relationships between maternal serum and placental tissue were found for 10 amino acids, indicating that active amino acid transport and accumulation by the human syncytiotrophoblast occurs as early as 7 weeks of gestation. The transplacental flux of most amino acid transport from maternal blood to the exocoelomic cavity was against a concentration gradient. The highest placental amino acid concentrations were found for taurine, glutamic acid, glycine and alanine. The amniotic fluid contained lower mean concentration of all amino acids than coelomic fluid and maternal serum. The concentration distribution of individual amino acids in coelomic and amniotic fluid were related indicating a passive transfer through the amniotic membrane. A coelomic-maternal gradient was observed in 19 out of 24 amino acids measured and positive correlations were found between maternal serum and coelomic fluid for concentrations of alpha-aminobutyric acid, tyrosine and histidine, suggesting that these amino acids are only partially retained and/or transferred more rapidly by the early placenta.

Alanine↗
PubMed1998

Prospective non-invasive monitoring of pregnancies complicated by red cell alloimmunization.

Our purpose was to evaluate the impact of non-invasive assessment of fetal anemia and anti-D antibody quantification on the timing and frequency of invasive procedures in pregnancies complicated by rhesus alloimmunization. Nineteen consecutive non-hydropic pregnancies referred to the fetal medicine center were assigned a prior risk category (none/mild, moderate or severe) and monitored by: (1) serial fetal measurements of umbilical vein maximal flow velocity (UVVmax), liver length and spleen perimeter measurements; and (2) serial anti-D antibody concentration. Invasive tests for fetal anemia (amniocentesis or fetal blood sampling) were deferred in the absence of abnormal ultrasound findings and/or rising antibody levels. In six cases serial non-invasive tests were normal with stable antibody levels, and no invasive tests were performed; four infants were mildly affected, one was unaffected and one required postnatal exchange transfusion. In the remaining 13 affected cases, amniocentesis was performed in nine cases for: elevated UVVmax alone (n = 3), elevated UVVmax and an increased antibody level (n = 2), or normal UVVmax with an increased antibody level (> 15 IU/ml) and severe prior risk category (n = 4). Six fetuses underwent fetal blood sampling (initial hematocrit 9-29%), and five of these had an elevated UVVmax. Liver length and spleen perimeter measurements were increased in only one anemic fetus (hematocrit 13%). Of 17 infants born alive, an elevated UVVmax prior to delivery was predictive of the need for exchange transfusion (six of seven cases with an elevated UVVmax vs. one of ten with a normal UVVmax; chi 2 = 5.73, p = 0.017 with Yates' correction). These preliminary data suggest that pregnancies with a mild or no history of fetal anemia may be monitored by a combination of serial antibody quantification and Doppler monitoring of UVVmax.

Adult↗
PubMed1998

Comparison of placental isoferritin levels in maternal serum and coelomic and amniotic fluids during first trimester human gestation.

Placental isoferritin (PLF) is present in serum at high concentrations throughout normal gestation. The current study compared PLF concentrations in first trimester maternal serum with those of amniotic and coelomic fluids in 25 healthy, pregnant women. Use of a specific enzyme-linked immunosorbent assay indicated concentrations high (22 +/- 3 U/ml) in maternal serum, whereas significantly lower values were detected in both coelomic and amniotic fluids (5 +/- 2 and 3 +/- 2 U/ml, respectively, P < 0.005). It was further demonstrated that when pure PLF was added to amniotic and coelomic fluids, the PLF levels remained low in each compartment, suggesting that bioproducts produced inside the gestational sac may interfere with the PLF immunoassay.

Amniotic Fluid↗
PubMed1998

Electrical potential difference between exocelomic fluid and maternal blood in early pregnancy.

The forces that drive transfer of solutes between maternal blood and embryo in early human pregnancy are poorly understood. The aim of this study was to determine whether there is an electrical potential difference (PD) between maternal blood and the exocelomic cavity and between maternal blood and the amniotic cavity in the normal human conceptus at or before 10 wk of pregnancy. We measured PD between a saline-filled catheter in a forearm vein of women undergoing termination of pregnancy for psychological reasons in the first trimester and a second saline-filled catheter in the exocelomic cavity or amniotic cavity of their conceptus. The mean (+/- SE) maternal blood/exocelomic cavity PD in eight women was 8.7 +/- 1.0 mV and the mean maternal blood/amniotic cavity PD in four of the women was 6.7 +/- 1.3 mV, embryo side negative for both sets of measurement. These data show that there is a PD between maternal and embryonic extracellular fluid in the first trimester that will directly influence exchange of ions between the two compartments.

Amniotic Fluid↗
PubMed1997

Audit of prenatal diagnosis for haemoglobin disorders in the United Kingdom: the first 20 years.

OBJECTIVES: To audit services for prenatal diagnosis for haemoglobin disorders in the United Kingdom. DESIGN: Comparison of the annual number of cases recorded in a United Kingdom register of prenatal diagnoses for haemoglobin disorders, with the annual number of pregnancies at risk of these disorders, by ethnic group and regional health authority. The number of pregnancies at risk was estimated using data on ethnic group from the 1991 census and data from the United Kingdom thalassaemia register, which records the number of babies born with thalassaemia. SETTING: The three national prenatal diagnosis centres for haemoglobin disorders. SUBJECTS: 2068 cases of prenatal diagnosis for haemoglobin disorders in the United Kingdom from 1974 to 1994. MAIN OUTCOME MEASURES: Utilisation of prenatal diagnosis by risk, ethnic group, and regional health authority. Proportion of referrals in the first trimester and before the birth of any affected child. RESULTS: National utilisation of prenatal diagnosis for haemoglobin disorders was around 20%. During the past 10 years it has remained steady at about 50% for thalassaemias and risen from 7% to 13% for sickle cell disorders. Utilisation for sickle cell disorders varies regionally from 2% to 20%. Utilisation for thalassaemias varies by ethnic group. It is almost 90% for Cypriots and ranges regionally for British Pakistanis from 0% to over 60%. About 60% of first prenatal diagnoses are done for couples without an affected child. Less than 50% of first referrals are in the first trimester. CONCLUSIONS: National utilisation of prenatal diagnosis for haemoglobin disorders is far lower than expected, and there are wide regional variations. A high proportion of referrals are still in the second trimester and after the birth of an affected child. The findings point to serious shortcomings in present antenatal screening practice and in local screening policies and to inadequate counselling resources, especially for British Pakistanis.

Africa↗
PubMed1997

Fetal and maternal plasma insulin-like growth factors and binding proteins in pregnancies with appropriate or retarded fetal growth.

A prospective observational study of 104 women was performed to study whether the insulin-like growth factor (IGF) system in pregnancy before labour is associated with reduced fetal growth. Fetal blood was obtained by cordocentesis for prenatal diagnosis or at elective caesarean delivery and a maternal sample was also obtained, IGF-1 and IGF-2 and their binding proteins -1 and -3 were measured by RIA. The 35 case were smaller than -2S.D.s by ultrasound abdominal circumference and birthweight and were subdivided into fetal growth retardation (FGR, n = 20) and small for gestational age (SGA, n = 15) by Doppler velocimetry and neonatal outcome. Controls (n = 69) were normally grown. Control maternal IGF-1 (r = 0.65, P < 0.0001) and IGFBP-3 (r = 0.46, P = 0.001) increased with advancing gestational age. In FGR cases, maternal IGF-1 was low (P = 0.0001) and IGFBP-1 was high (P = 0.03) and maternal IGF-2 was low in SGA (P = 0.005). In the SGA fetus, IGF-2 was low (P = 0.0009) and IGFBP-3 (P = 0.02) was high. In FGR, IGFBP-1 (P < 0.0001) and IGFBP-3 (P = 0.002) were both elevated. These data do not support the hypothesis that fetal IGF-1 deficiency is a common cause of FGR. Elevated binding proteins may lead to a relative deficiency of free IGF but changes in binding proteins may be secondary to metabolic changes. In FGR, maternal IGF-1 was low with high binding proteins, so this system may be important in controlling placental transfer.

Embryonic and Fetal Development↗
PubMed1997

Prenatal detection of Hb mutations using transcervical cells.

Prenatal diagnoses were performed on six selected pairs of parents known to be carriers of Hb mutations by testing transcervical cells (TCCs) retrieved, prior to chorionic villus sampling (CVS), by aspiration of the cervical mucus from the pregnant mothers at 10-12 weeks of gestation. A concordance between the results of testing chorionic villus cells and isolated clumps of trophoblastic cellular elements was observed in four of the six cases.

Cervix Uteri↗