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Biomedical subjects

P Bayliss

Publications and source records attributed to P Bayliss.

11 recordsLinked to original sources
PubMed2000

Genetic analysis, phenotypic diagnosis, and risk of venous thrombosis in families with inherited deficiencies of protein S.

Protein S deficiency is a recognized risk factor for venous thrombosis. Of all the inherited thrombophilic conditions, it remains the most difficult to diagnose because of phenotypic variability, which can lead to inconclusive results. We have overcome this problem by studying a cohort of patients from a single center where the diagnosis was confirmed at the genetic level. Twenty-eight index patients with protein S deficiency and a PROS1 gene defect were studied, together with 109 first-degree relatives. To avoid selection bias, we confined analysis of total and free protein S levels and thrombotic risk to the patients' relatives. In this group of relatives, a low free protein S level was the most reliable predictor of a PROS1 gene defect (sensitivity 97.7%, specificity 100%). First-degree relatives with a PROS1 gene defect had a 5.0-fold higher risk of thrombosis (95% confidence interval, 1. 5-16.8) than those with a normal PROS1 gene and no other recognized thrombophilic defect. Although pregnancy/puerperium and immobility/trauma were important precipitating factors for thrombosis, almost half of the events were spontaneous. Relatives with splice-site or major structural defects in the PROS1 gene were more likely to have had a thrombotic event and had significantly lower total and free protein S levels than those relatives having missense mutations. We conclude that persons with PROS1 gene defects and protein S deficiency are at increased risk of thrombosis and that free protein S estimation offers the most reliable way of diagnosing the deficiency. (Blood. 2000;95:1935-1941)

Adult↗
PubMed2000

Farnesylation is involved in meristem organization in Arabidopsis.

Although studies in plant and animal cell culture systems indicate farnesylation is required for normal cell cycle progression, how this lipid modification of select proteins translates into whole-organism developmental decisions involving cell proliferation or differentiation is largely unknown. The era1 mutant of the higher plant Arabidopsis thaliana (L.) Heynh. offers a unique opportunity to understand the role farnesylation may play in regulating various processes during the development of a multicellular organism. Loss of farnesylation affects many aspects of Arabidopsis growth and development. In particular, apical and axillary meristem development is altered and these phenotypes are contingent on the growth conditions.

Abscisic Acid↗
PubMed1997

Pregnancy complicated by primary aldosteronism.

Pregnancy is rarely complicated by aldosteronism. We report the case of a 32-year-old woman who became pregnant soon after primary aldosteronism was diagnosed. Only antihypertensive medication and oral potassium supplementation were required in addition to routine prenatal care. A healthy female infant was delivered at term. In this case, no adrenal adenoma was identified. We discuss management of aldosteronism in pregnancy and review the literature.

Adult↗
PubMed1997

Co-inheritance of the 20210A allele of the prothrombin gene increases the risk of thrombosis in subjects with familial thrombophilia.

The presence of the 20210A allele of the prothrombin (PT) gene has recently been shown to be a risk factor for venous thromboembolism. This is probably mediated through increased plasma prothrombin levels. The aim of this study was to compare the prevalence of the prothrombin 20210A allele in control subjects and in subjects with recognised thrombophilia and to establish whether the additional inheritance of the PT 20210A allele is associated with an increased risk of venous thromboembolism. 101 subjects with a history of venous thromboembolism and diagnosed as having either factor V Leiden (R506Q) or heritable deficiencies of protein C, protein S or antithrombin were studied. The prevalence of the PT 20210A allele in this group was compared with the results obtained for 150 control subjects. In addition, the relationships were examined between genetic status and the number of documented thromboembolic episodes, and between plasma prothrombin levels and possession of the PT 20210A allele. 8 (7.9%) of the 101 patients were also heterozygous for the PT 20210A allele. This compares with 0.7% in the control subjects (p = 0.005). After exclusion of patients on warfarin, the mean plasma prothrombin of 113 subjects without 20210A was 1.09 U/ml, as compared with 1.32 U/ml in 8 with the allele (p = 0.0002). Among the 101 patients with either factor V Leiden, protein S deficiency, protein C deficiency or antithrombin deficiency, the age adjusted mean (SD) number of venous thromboembolic episodes at diagnosis was 3.7 (1.5) in those with the PT 20210A allele, as compared with 1.9 (1.1) in those without (p = 0.0001). We have demonstrated that the prevalence of the PT 20210A allele is significantly greater in subjects with venous thrombosis and characterised heritable thrombophilia than in normal control subjects and that the additional inheritance of PT 20210A is associated with an increased risk of venous thromboembolism. We have also confirmed that plasma prothrombin levels are significantly greater in subjects possessing the PT 20210A compared with those who do not.

Adolescent↗
PubMed1995

Partial hydatidiform molar pregnancy presenting with severe preeclampsia prior to twenty weeks gestation: a case report and review of the literature.

A previously healthy 37-year-old Latin American female presented at 17 6/7 weeks gestation with clinical manifestations of preeclampsia. Ultrasound revealed a growth-retarded fetus with hypoechoic bowel, a thickened cystic placenta, bilateral multicystic adnexal masses, and oligohydramnios. The patient had laboratory evidence of hyperthyroidism and the maternal serum alpha-fetoprotein was 12.3 multiples of the mean. Subclinical disseminated intravascular coagulation rapidly ensued and an induction of labor was performed. This was productive of a 110-g female fetus with a markedly distended abdomen and syndactyly. The placenta weighted 650 g with gross hydropic changes throughout. The clinical aspects of this case and review of the literature on partial molar pregnancies will be discussed.

Adult↗
PubMed1994

A case for a code of ethics.

Ethical dilemmas in business and health have become a familiar topic over recent times. Doubts remain, however, as to whether a code should be produced and the recently issued IHSM consultation paper argues the case for "a statement of primary values" rather than a code of ethics. In a second article on the subject, Paul Bayliss examines the importance of having a code, looks at some of the contextual issues and suggests an approach to producing one.

Administrative Personnel↗
PubMed1994

Should managers have a code of conduct?

Much attention is currently being given to values and ethics in the NHS. Issues of accountability are being explored as a consequence of the Cadbury report. The Institute of Health Services Management (IHSM) is considering whether managers should have a code of ethics. Central to this issue is what managers themselves think; the application of such a code may well stand or fall by whether managers are prepared to have ownership of it, and are prepared to make it work. Paul Bayliss reports on a survey of managers' views.

Administrative Personnel↗
PubMed1992

Effect of induced supraventricular tachycardias on changes in urine output and plasma hormone levels in man.

1. A symptomatic diuresis, polyuria, sometimes accompanies paroxysmal tachycardias in man. A study was undertaken in patients with inducible supraventricular tachycardia, irrespective of the symptom of polyuria, to measure simultaneous changes in urine output and plasma hormone levels during the arrhythmia. 2. During 14 episodes of induced tachycardia in 10 patients, there was a significant increase in mean urine flow, which was independent of the state of patient hydration. During a mean tachycardia duration of 30 +/- 3 min, the mean group urine flow increased from 3.2 +/- 2.3 ml/min to 7.6 +/- 3.7 ml/min (P less than 0.001). This was characterized by a consistent increase in free water excretion and a variable increase in sodium excretion. 3. The plasma atrial natriuretic peptide level (five patients) significantly increased from 7.6 +/- 4.6 pg/ml to 34.6 +/- 21.7 pg/ml (P less than 0.02) during the arrhythmia. There was no significant change in the plasma arginine-vasopressin level and a non-significant reduction in plasma renin activity. 4. This study has shown that induced supraventricular tachycardias in man are accompanied by a significant diuresis. The mechanisms responsible remain unknown, but do not appear to involve the plasma arginine-vasopressin level alone.

Adult↗
PubMed1989

Prolactin and thyrotropin responses to nursing during the early puerperium.

This study investigated the possible role of thyrotropin-releasing hormone (TRH) as a physiologic prolactin-releasing factor by measuring prolactin (PRL) and thyrotropin (TSH) responses to nursing. Eight women had serum samples drawn at 15-minute intervals for 1 hour while nursing during three separate periods in the hour while nursing during three separate periods in the first month postpartum. The samples were frozen and assayed in a single batch for PRL and TSH. Mean PRL levels during suckling increased greater than 50% over baseline values in all three sampling sessions. In contrast, suckling had no effect on circulating TSH. Our data fail to support the previously reported observation of a release of TSH in response to nursing and provide further indirect evidence that TRH is not responsible for the brisk release of PRL with suckling.

Adolescent↗