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Biomedical subjects

R D Wilson

Publications and source records attributed to R D Wilson.

At least 73 records · Page 4Linked to original sources
PubMed1991

Chorionic villus sampling: analysis of fetal losses to delivery, placental pathology, and cervical microbiology.

A population of 1639 patients were seen for chorionic villus sampling (CVS). Embryonic death was identified at ultrasound in 5.3 per cent of patients. The number of patients undergoing CVS was 1551, with 1416 transcervical procedures and 135 transabdominal procedures. The most common indication for CVS was advanced maternal age. Spontaneous pregnancy losses identified by increased risk of pregnancy loss with increasing aspiration attempts. The total fetal loss for this population was 5.4 per cent with the pregnancy loss estimated due to procedure being 1.2 per cent. Analysis of placentae from patients having CVS and amniocentesis showed no differences. Microbiological assessment prior to CVS was similar to previous publications.

Adult↗
PubMed1991

Confirmation of CVS mosaicism in term placentae and high frequency of intrauterine growth retardation association with confined placental mosaicism.

About 2 per cent of specimens from chorionic villus sampling (CVS) analysed either on direct preparation of cytotrophoblast cells or after culture of mesenchymal stroma reveal confined placental mosaicism (CPM), most commonly involving chromosomal trisomy. A significantly higher rate of prenatal loss (22 per cent) as well as the presence of intrauterine growth retardation (IUGR) has been reported among pregnancies with CPM. To evaluate more precisely the effect of these aneuploid cell lines confined to the placenta on intrauterine fetal growth and fetal survival, we have studied 34 term placentae from pregnancies with CPM diagnosed on CVS and confirmed identical mosaicism in 17 of these placentae. There was a direct correlation between a high number of aneuploid cells present at CVS and a high likelihood of their detection in term placenta. Also, the proportion of aneuploid cells in the mosaic term placentae correlated with that observed in CVS specimens. Among 17 gestations with confirmed CPM at delivery, there were six cases of IUGR identified, five in liveborns and one associated with intrauterine death.

Amnion↗
PubMed1991

The effects of comfrey derived pyrrolizidine alkaloids on rat liver.

Three groups of young adult rats were fed pyrrolizidine alkaloids derived from Russian comfrey to study the effects of the herb on the liver. Group I animals received a single dose of 200 mg/kg body wt, Group II 100 mg/kg three times a week for 3 weeks and Group III 50 mg/kg three times a week for 3 weeks. All rats showed light and electron-microscopic evidence of liver damage, the severity of which was dose dependent. There was swelling of hepatocytes and hemorrhagic necrosis of perivenular cells. There was a concomitant loss of sinusoidal lining cells with disruption of sinusoidal wall and the sinusoids were filled with cellular debris, hepatocyte organelles and red blood cells. Extravasation of red blood cells was evident. Terminal hepatic venules were narrowed by intimal proliferation, and in Group II and III, reiculin fibres radiated from these vessels. These appearances have been described in veno-occlusive disease due to pyrrolizidine alkaloids from other plant sources such as Senecio and Crotalaria. The safety of comfrey, a widely used herb, in relation to human consumption requires further investigation.

Animals↗
PubMed1991

Recurrent spontaneous pregnancy loss. Investigation and reproductive follow-up.

Between July 1, 1985, and Dec 31, 1988, 187 women referred to the University of British Columbia Medical Genetics Clinical Unit for two or more consecutive, unexplained, spontaneous pregnancy losses were evaluated for seven categories of possible etiology. Follow-up of the total subsequent reproductive experience was obtained in 171 cases. For those who became pregnant, achievement of a live birth was tabulated according to the number of previous pregnancy losses, age at the investigation and abnormalities found in the investigation. Overall, 81.8% of those who became pregnant after the evaluation and with a known outcome or outcomes at follow-up had a live birth-78% of primary aborters (no previous liveborn infant) and 86.3% of secondary aborters (previous liveborn infant).

Abortion, Habitual↗
PubMed1989

ITP in pregnancy: use of the bleeding time as an indicator for treatment.

ITP is a relatively common disorder seen in pregnancy. Current recommendations for management of patient with ITP recommend maintaining the platelet count above 50 x 10(9)/L and the bleeding time less than 20 min. It has been well documented that the bleeding time in ITP is disproportionately shortened in many patients relative to the platelet count. We present a prospective study of 24 ITP patients in whom the bleeding time was used as an indicator for therapeutic intervention in pregnancy. Indications for therapy with prednisone and/or intravenous gammaglobulin were the following: significant clinical hemorrhage due to thrombocytopenia; bleeding time of greater than 20 min at the baseline platelet count; for normalization of hemostasis prior to delivery or surgical procedure. Caesarean section was performed only in cases in which there were obstetrical indications for this mode of delivery or when the fetal platelet count (obtained by fetal scalp vein sample) was less than 50 x 10(9)/L. Of 24 patients with ITP, eight had significant thrombocytopenia (platelet count less than 50 x 10(9)/L) throughout pregnancy. Only two patients required prolonged prednisone therapy. Both suffered side effects of chronic prednisone administration. Four patients were treated with prednisone for a short course (10-14 days) at term to improve hemostasis for delivery. One patient was treated with intravenous gammaglobulin at term in an effort to prevent severe neonatal thrombocytopenia. Seven patients required caesarean section; the remaining 17 patients underwent vaginal delivery. Only one minor bleeding complication was seen - a small wound hematoma post caesarean section. In summary, using the bleeding time as an indicator for therapeutic intervention, treatment of ITP in pregnancy can be minimized. Thus, therapy related toxicity can be avoided.

Autoimmune Diseases↗
PubMed1989

Teratogenic assessment of 2,4-dichlorophenol in Fischer 344 rats.

The potential maternal, embryotoxic, and teratogenic parameters of 2,4-dichlorophenol (2,4-DCP) were evaluated in Fischer 344 rats following oral administration in corn oil on Days 6 through 15 of gestation. Dose levels were 0, 200, 375, and 750 mg/kg/day. Females were sacrificed on Gestation Day 20 and cesarean sections performed. The fetuses were weighed, sexed, measured for crown-rump length, and examined for external malformations. A skeletal examination was conducted on one-half of the fetuses after staining with alizarin red S. The remaining fetuses were fixed in Bouin's solution and examined for visceral anomalies and developmental variations. Maternal body weight gain inhibition occurred in all 2,4-dichlorophenol-treated groups during the treatment period. Four treatment-related deaths occurred in the 750 mg/kg/day group. Additional indicators of maternal toxicity included urogenital staining of the fur at all levels tested, and an increased incidence of hair loss and respiratory rales at the 750 mg/kg/day level. Fetal examinations did not reveal differences in the incidence of external, visceral, or skeletal fetal malformations in any treatment group, when compared with the control group. A slight increase in early embryonic death occurred in the high-dose group only. Fetal weights were lower in the high-dose group than in the control group. Variations in skeletal structure were expressed among fetuses exposed to 750 mg/kg/day during organogenesis. These included delayed ossification of sternal elements and vertebral arches. The reduced fetal weights, intrauterine survival, and retarded ossification may represent a slight degree of embryotoxicity or fetotoxicity in this group. The test material was not teratogenic at any dose level.

Animals↗
PubMed1989

Clinical follow-up of prenatally diagnosed isolated ventriculomegaly, microcephaly and encephalocele.

This retrospective review identified all cases of isolated ventriculomegaly (without spina bifida), encephalocele and microcephaly in approximately 22,000 consecutive patients through the Ultrasound Department at the University of British Columbia, Grace Hospital. 17 cases of isolated ventriculomegaly, 16 cases of microcephaly and 6 cases of encephalocele were identified. Isolated ventriculomegaly and encephalocele were accurately diagnosed prenatally while microcephaly was not consistently identified prenatally. Patients with isolated ventriculomegaly had a positive family history for cranial abnormalities in 24%. The prognosis is difficult to predict for fetuses with ventriculomegaly, but severe ventriculomegaly generally produced a poor outcome while mild or moderate ventriculomegaly resulted in normal development or marginal developmental delay. Chromosome analysis is recommended in all patients with central nervous system lesions and viral studies are recommended with ventriculomegaly and microcephaly.

Brain↗
PubMed1989

A rural retrieval service.

In rural areas critically ill patients are transferred frequently from smaller to larger hospitals. The time spent in transit may influence their outcome. Intensive care facilities in the Central Western Health Region of N.S.W. are located at The Orange Base Hospital and many of the patients admitted to that unit each year are transferred from other hospitals. Since 1984 The Orange Base Hospital, with the N.S.W. Ambulance Service, has offered a retrieval service, and during the three years 1984-86, 135 patients have been retrieved. The service has been well accepted, the only major criticism from the referring hospitals being the extra time taken for some patients suffering from trauma to receive definitive treatment. By improving communications and developing a regional plan, this difficulty may to some extent by overcome.

Ambulances↗
PubMed1988

Cold-induced abortion in paramyotonia congenita.

Paramyotonia congenita is a rare autosomal dominant disorder with complete penetrance. Its most typical clinical feature is the precipitation of active myotonia by exposure to cold. We report a case of cold-induced abortion in a woman with paramyotonia congenita.

Abortion, Spontaneous↗
PubMed1988

Prenatal diagnosis of asplenia/polysplenia syndrome.

Complex congenital heart disease with atrioventricular block was detected prenatally in two fetuses at 34 and 28 weeks' gestation. The spleen was not seen on ultrasonographic examination in either fetus, suggesting polysplenia/asplenia syndrome. Both infants died shortly after delivery and the autopsies confirmed this diagnosis. Recommendations for sonographic screening of the fetal spleen in cases of prenatal detection of complex heart disease or cardiac dysrhythmia are discussed.

Abnormalities, Multiple↗
PubMed1988

In vitro activity of A-56619 and A-56620 against multi-resistant and routine clinical isolates.

A-56619 and A-56620 are two new quinolone compounds that are currently being studied. They were found to be active against multi-resistant and routine isolates of Staphylococcus aureus, enterobacteria, aminoglycoside-sensitive and resistant strains of Pseudomonas aeruginosa. Most of the enterobacteria were inhibited by 0.5-1 mg/l of A-56620. A-56619 was less active, concentrations of 1-4 mg/l being needed for 90% inhibition. Both the compounds were active at concentrations of 0.5-1 mg/l against staphylococci, including multi-resistant S. aureus. The MIC90 for P. aeruginosa was 1-2 mg/l for A-56620 and 8 mg/l for A-56619.

Anti-Bacterial Agents↗
PubMed1988

Clinical follow-up of fetal urinary tract anomalies diagnosed prenatally by ultrasound.

This retrospective review identified 122 cases with a prenatal diagnosis of genitourinary anomalies and categorized them into parenchymal and collecting system abnormalities. Comparisons were made between the anatomical groups for indications for ultrasound, average gestational age at positive and negative renal ultrasound diagnosis, amniotic fluid volume and pregnancy outcome with postnatal diagnosis. The results indicated that parenchymal abnormalities were detected earlier in gestation than collecting system anomalies. Additional fetal anomalies were more often present in the parenchymal group. Chromosome abnormalities were present in 5% of the urinary tract abnormalities. Parenchymal abnormalities were more likely to have oligohydramnios and a higher morality rate.

Female↗
PubMed1987

First-trimester prenatal diagnosis for Huntington's disease with DNA probes.

Polymorphic DNA probes linked to the locus for Huntington disease (HD) were used for prenatal diagnosis of a 10-week fetus at 25% risk for the disease. The fetus proved to have a 48% risk of having inherited the HD mutation which was similar to that for the at-risk parent (50%). On this basis the parents elected to terminate the pregnancy. When appropriate family members are available and DNA studies are informative, prenatal diagnosis of HD with polymorphic DNA probes can determine the at-risk status of the fetus with 96% accuracy.

Adult↗
PubMed1987

Confined chorionic mosaicism in prenatal diagnosis.

Confined chorionic mosaicism, detected commonly on chorionic villus sampling (CVS) and occasionally in cultured amniotic fluid cells, is described in five pregnancies that showed confined chorionic mosaicism for trisomies 12, 13, 14, 17 and a marker chromosome. Cytogenetic findings in these pregnancies support the conclusion that within chorion some chromosomal mosaicism are confined to the trophectoderm derivatives while others to the extra-embryonic mesoderm. The etiology of confined chorionic mosaicism is discussed in relation to a significant role of multiple cell lineages contributing to the early development of placenta. The need is indicated for the use of both direct and long-term cultures in CVS prenatal diagnosis, and for the confirmatory testing of fetal blood or amniotic fluid in cases where mosaicism is detected in chorionic villi.

Adult↗