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P Soothill

Publications and source records attributed to P Soothill.

35 records · Page 2Linked to original sources
PubMed1996

First trimester prenatal diagnosis of Smith-Lemli-Opitz syndrome (7-dehydrocholesterol reductase deficiency).

In Smith-Lemli-Opitz syndrome (SLOs), 7-dehydrocholesterol (7-DHC) accumulated because there is a block in the pathway for synthesis of cholesterol via 7-DHC. Prenatal diagnosis of SLOs has been achieved by analysis of 7-DHC in amniotic fluid obtained at 16-18 wk from pregnancies at risk. The purpose of this study was to investigate 7-DHC and cholesterol concentrations in chorionic villus (CV) samples with a view to performing first trimester prenatal diagnosis. Using a sensitive gas chromatography-mass spectrometry assay it was possible to detect 7-DHC in CV samples obtained as early as 7 wk of gestation. The ration of 7-DHC to cholesterol in placental tissue was shown to be relatively constant over the gestational period of 7-18 wk. We therefore proceeded to analyze the 7-DHC/cholesterol ration in CV samples taken at 10-12 wk of gestation from three pregnancies at risk for SLOs. The results were as follows: patient A, 1.10 x 10(-3); patient B, 1.80 x 10(-3); patient C, 0.091; control range for CVS (8-12 wk), 3.10 x 10(-4) to 1.62 x 10(-3) (mean +/- 2SD; n = 5). The fetus of patient C was diagnosed as affected by SLOs, and the parents requested termination. Analysis of cultured skin fibroblasts confirmed the diagnosis. Pregnancies A and B were diagnosed unaffected, and this was confirmed first by amniocentesis and then by the birth of normal infants at term. We conclude that synthesis of cholesterol via 7-DHC is occurring in the placenta and/or fetus at 10 wk of gestation and that prenatal diagnosis by CV biopsy is possible.

Amniocentesis↗
PubMed1996

Matrix metalloproteinases in the formation of human synovial joint cavities.

Matrix metalloproteinases (MMPs) have been implicated in tissue remodelling in growth and development. A histochemical study of human fetal limbs was undertaken to assess the presence, and consequently the possible role, of MMPs and their inhibitor TIMP-1 (tissue inhibitor of metalloproteinases-1) in synovial joint cavity formation. Cryostat sections of fetal limbs from 7 to 14 wk gestation were stained with specific antibodies to collagenase (MMP-1), gelantinases A (MMP-2) and B (MMP-9), stromelysin (MMP-3) and TIMP-1. Immunoreactive (IR) MMP-1, MMP-2 and MMP-3 were seen chiefly in chondrocytes, but in all cases in zones distant from the joint line before cavity formation. IR-MMP-1 and MMP-2 were also localised both in synovium and on the articular surfaces of joints after cavity formation. In addition IR-MMP-2 was seen in a "collar' of perichondrium alongside the hypertrophic zone of chondrocytes and weakly in bone marrow spaces. IR-MMP-9 was seen in neutrophil leucocytes and in bone marrow spaces. IR-TIMP-1 was generally distributed in connective tissue cells. No IR-MMP (1, 2,3 or 9) was seen along potential joint lines before or at the time of cavity formation, nor was there aspecific decrease in IR-TIMP-1 at this site. These findings confirm a role for metalloproteinases in developmental processes such as cartilage remodelling and bone marrow space formation. MMP-1 and MMP-2 may be involved in the remodelling of developing synovial tissue and the articular surfaces subsequent to cavity formation. However, we have failed to find evidence to indicate that the loss of tissue strength at the joint line which allows synovial joint cavity formation relates to high local levels of MMPS.

Cartilage, Articular↗
PubMed1995

KAL, a gene mutated in Kallmann's syndrome, is expressed in the first trimester of human development.

Kallmann's syndrome (KS) is characterised by the association of anosmia and isolated hypogonadotrophic hypogonadism (IHH). Mutations of the KAL gene which is located at Xp22.3 cause X-linked KS (XKS). In this study we used the reverse transcriptase polymerase chain reaction and in situ hybridisation to examine the developmental expression of KAL in the first trimester of pregnancy, the earliest stage of human gestation examined thus far. At 45 days after fertilisation KAL mRNA was detected in the spinal cord, the mesonephros and metanephros but not in the brain. Later in gestation, at 11 weeks, the gene was expressed in the developing olfactory bulb, retina and kidney. This expression pattern correlates with the clinical findings in XKS since olfactory bulb dysgenesis with subsequent defective neural migration causes anosmia and IHH. Additionally, renal agenesis occurs in 40% of patients. Therefore this study provides strong evidence that KAL expression is required for the normal development of the olfactory bulb and kidney in the first trimester of human pregnancy.

Base Sequence↗
PubMed1995

Molecular evidence of fetal-derived chromosome 21 markers (STRs) in transcervical samples.

Transcervical cells (TCCs), collected by flushing or aspiration at 8-13 weeks of gestation, were analysed for the presence of fetal-derived DNA sequences. DNA extracted from maternal peripheral blood, TCC samples, and placental tissue was amplified by the polymerase chain reaction (PCR) to detect small tandem repeat (STR) markers specific to chromosome 21. STR products of fetal origin could be clearly observed in four TCC samples. TCC samples collected by flushing or aspiration were also analysed by fluorescent in situ hybridization (FISH) using X and Y probes simultaneously: 46,XY cells could be detected in all TCC samples obtained from mothers with male fetuses.

Base Sequence↗
PubMed1995

Corticotrophin-releasing hormone-binding protein in human fetal plasma.

During pregnancy maternal plasma corticotrophin-releasing hormone (CRH) levels rise 1000-fold whilst fetal plasma levels are often 100-fold higher than the concentrations seen in normal non-pregnant human plasma. Despite these high CRH levels neither the maternal nor fetal pituitary releases excessive amounts of ACTH. A specific CRH-binding protein (CRHBP) exists in the maternal circulation which is able to bind and inactivate the ACTH releasing activity of CRH. In this study we have used a specific CRHBP radioimmunoassay to determine the level of CRHBP in fetal and maternal plasma samples. Fetal samples were collected by cordocentesis between 20 and 33 weeks gestation and matched maternal samples were taken by venepuncture at the same time. In a second study, plasma samples were collected from 8 women at fortnightly intervals from week 20 to term, at labour and post-partum. A fetal sample, taken from the umbilical vein, was collected immediately post-delivery. The mean maternal CRHBP concentration for the samples collected between 20 and 33 weeks (n = 23) was 8.12 nmol/l and the fetal level was 8.62 nmol/l. Data from the second study showed that at term the maternal CRHBP concentration decreased significantly (P < 0.025) to 6.32 nmol/l. The fetal CRHBP level also decreased significantly (P < 0.001) at term to a level of 5.84 nmol/l. The CRHBP in both fetal and maternal plasma was shown to be functional by 125I-CRH binding and gel permeation chromatography. The capacity of maternal and fetal plasma to bind 125I-CRH decreased at term in agreement with the quantitation of plasma CRHBP by radioimmunoassay.

Carrier Proteins↗
PubMed1994

The formation of human synovial joint cavities: a possible role for hyaluronan and CD44 in altered interzone cohesion.

During fetal development, cavitation occurs within the primitive skeleton along planes destined to become the articular surfaces of synovial joints. A histochemical study of human fetal limbs was undertaken to identify the cell types involved in this cavitation and the possible role of interactions between cells and extracellular matrix. Cryostat sections were stained with antibodies to CD68, factor VIII related antigen, prolyl hydroxylase, beta 1 integrin, VCAM-1, proliferating cell nuclear antigen, chondroitin-4 sulphate, chondroitin-6-sulphate, hyaluronan synthase and CD44. Similar sections were reacted for uridine diphosphoglucose dehydrogenase (UDPGD) and acid phosphatase activity. Hyaluronan was demonstrated using an aggrecan core protein hyaluronan binding region probe. Macrophages were present prior to cavitation in the periphery of joint interzones but not at the presumptive joint line in the central interzone. Fibroblastic cells were present throughout. Absence of local VCAM-1 expression indicated that cavitation was temporally distinct from full fibroblast-like synoviocyte differentiation. CD44 was expressed by interzone cells at all stages. Staining for hyaluronan and hyaluronan synthase, but not chondroitin sulphates was present in the interzone before and at the time of cavitation. UDPGD activity was increased in a narrow band of cells at the presumptive joint line prior to cavitation. These findings suggest that joint cavitation is dependent on the behaviour of fibroblastic cells and/or adjacent chondrocytes, rather than macrophages. Since UDPGD activity is involved in hyaluronan synthesis, it is proposed that joint cavitation is facilitated by a rise in local hyaluronan concentration in an area of tissue where cohesion is dependent on the interaction between cellular CD44 and extracellular hyaluronan. As proposed by Toole et al. (1984) such a local rise in hyaluronan concentration may lead to a switch from intercellular cohesion to dissociation, leading to tissue cavitation.

Ankle Joint↗
PubMed1993

Detection of trisomy 18 and Y-derived sequences in fetal nucleated cells obtained by transcervical flushing.

A procedure which combines the collection of fetal cells by transcervical flushing and in situ hybridisation techniques on nuclei in interphase was used to detect trisomy 18 in a fetus at 12 weeks of gestation. Using a primed in situ labelling method, we could also detect Y-specific sequences in a small percentage of transcervically flushed cells obtained at 8-12 weeks from pregnant women with male fetuses. This approach seems to be suitable for prenatal diagnosis of major chromosomal abnormalities and other selected inherited disorders very early in gestation.

Adult↗
PubMedDate not supplied

Parvovirus as a differential diagnosis of hydrops fetalis in the first trimester.

We report a case of fetal parvovirus B19 infection which appears to have resulted in hydrops in the first trimester. An ultrasound scan performed at the booking visit of a woman in the first trimester showed generalised oedema. Karyotyping to exclude a fetal abnormality was normal. Maternal radioimmunoassay serological investigations showed parvovirus B19 IgG and IgM. Post-mortem analysis revealed intranuclear inclusion bodies typical of parvovirus in the erythroid cells in the liver and in the myocardium.

Adult↗
PubMedDate not supplied

Prenatal detection of facial clefts.

OBJECTIVES: To determine (1) the antenatal detection rate for isolated cleft lip and/or cleft palate during the routine anomaly scan; (2) the correlation between prenatal diagnosis and postnatal findings, and (3) the association of apparently isolated cleft lip and/or cleft palate with other anomalies, in particular chromosomal abnormalities. METHOD: A population-based retrospective analysis of all cases of isolated cleft lip and/or cleft during an 8-year period in an academic teaching hospital in the UK. RESULTS: Thirty-nine cases of isolated cleft lip and/or cleft palate were identified among deliveries at the hospital. Twenty-eight cases had a routine anomaly scan. Fourteen cases were detected prenatally (sensitivity 50%). None of the isolated cleft palates was detected, while 14 of 20 cases of cleft lip (70%) were detected. One of the isolated cases of cleft lip was associated with trisomy 21, while 3 of the isolated cleft palate cases were associated with the Pierre Robin syndrome. In all cases, an antenatal diagnosis of cleft was confirmed following delivery or post-mortem examination (specificity 100%). CONCLUSIONS: Ultrasound is a useful tool in screening for cleft lip with or without cleft palate, but not for cleft palate alone. Even with an isolated cleft lip, there is an increased risk of chromosomal abnormality. The role of prenatal education and support is extremely important in the preparation of prospective parents and can help alleviate the shock which occurs when there is an unexpected cleft at birth.

Cleft Lip↗
PubMedDate not supplied

Management of anti-Rhesus-D antibodies in pregnancy: a review from 1994 to 1998.

OBJECTIVE: To review our management of anti-Rhesus-D antibodies in pregnancy over a 5-year period in order to assess possible changes in the management or prognosis which may have developed with time. METHOD: Retrospective analysis of prospectively collected data from 31 pregnancies with maternal anti-D levels >4 IU/ml and in which the fetus was Rhesus positive. RESULTS: There were a total of 30 amniocenteses, 8 cordocenteses, and 54 fetal blood transfusions performed. When undertaken as the first procedure, the mean gestational age at amniocentesis was 30 weeks as compared with 25 weeks for fetal blood sampling/transfusion (p < 0.05). The median anti-D level at the first procedure was 24 IU/ml for amniocentesis and 64 IU/ml for fetal blood sampling. Of the 54 blood transfusions, 43 were intravascular, 4 were intraperitoneal, and 7 transfusions were both intravascular and intraperitoneal. CONCLUSIONS: Intravascular as opposed to intraperitoneal transfusions were found to be the main method of transfusion in the later years in this study, a finding which was expected with improved sonographic equipment. Apart from this, management and prognosis of anti-D red cell isoimmunisation in pregnancy have remained relatively stable since the 1980s. Amniocentesis was useful in the management of such pregnancies, especially as an initial procedure in the cases with a lower initial anti-D level. In this series 90% of the fetuses requiring blood transfusion, but were without hydrops, survived, whereas this was about 70%, if they had become hydropic (this latter figure was reduced by 2 hydropic deaths before 20 weeks' gestation in the same very severely affected woman).

Amniocentesis↗
PubMedDate not supplied

Fetal and perinatal medicine.

Fetal medicine, like this journal, is about 30 years old. In the 1960s access to the fetus was only possible around the time of birth, leading to the concept of 'perinatal medicine'. However, as ultrasonography, invasive procedures and genetics provided the necessary tools, it became clear that events in the preceding months are usually much more important than those around birth. The term perinatal medicine has therefore been replaced by fetal medicine.

Counseling↗