Search PubMed⌕ Search

Biomedical subjects

Alan Cameron

Publications and source records attributed to Alan Cameron.

8 recordsLinked to original sources
PubMed2004

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop.

BACKGROUND & AIMS: The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues. METHODS: A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion. RESULTS: There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia. CONCLUSIONS: Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Adenocarcinoma↗
PubMed2003

Maternal docosahexaenoic acid supplementation and fetal accretion.

Docosahexaenoic acid (DHA) (22 : 6n-3) is a polyunsaturated fatty acid that is an essential constituent of membranes, particularly of the nervous system. Infants acquire DHA from their mothers, either prenatally via the placenta or postnatally in milk. The present study aimed to test the hypothesis that maternal supplementation during the second and third trimesters of pregnancy enriches maternal and/or fetal DHA status. In a randomised, prospective, double-blind study 100 mothers received either fish-oil capsules containing 400 mg DHA/g (200 mg/d) (n 50), or placebo containing 810 mg oleic acid/g (400 mg/d) (n 50) from 15 weeks gestation until term. Venous blood samples were obtained from mothers at 15, 28 and 40 weeks, and from the umbilical cord at birth. Total fatty acids in plasma and erythrocytes were analysed by GC-MS. There were no significant differences between maternal groups in baseline DHA, as a proportion of total fatty acids (g/100 g total fatty acids) or concentration (nmol/ml), in plasma and erythrocytes. DHA concentrations in plasma at 28 weeks (P=0.02) and erythrocytes at both 28 weeks (P=0.03) and term (P=0.02) were 20 % higher in supplemented mothers than the placebo group. DHA accounted for a higher proportion of total fatty acids in erythrocytes of supplemented mothers at 28 weeks (P=0.003) and term (P=0.01). There were no significant differences between groups in DHA (g/100 g total fatty acids or nmol/l) in cord blood. Maternal DHA status was maximal in mid-trimester and declined to term, at a lower rate in supplemented compared with unsupplemented mothers. Maternal DHA supplementation significantly increases maternal DHA status and limits the last trimester decline in maternal status, aiding preferential transfer of DHA from mother to fetus.

Dietary Supplements↗
PubMed2002

Outcomes of pregnancies diagnosed with Klinefelter syndrome: the possible influence of health professionals.

OBJECTIVE: To describe the association between the outcomes of pregnancies diagnosed with Klinefelter syndrome (KS) and the specialty of the health professional providing pre- and post-diagnostic counselling. METHOD: Data were extracted from the case notes of the 111 cases of KS diagnosed prenatally between 1986 and 1997 in eight geographical regions in five European countries. The data extracted included: outcome of pregnancy, maternal age, social class, parity, gestational age at diagnosis, year of diagnosis and specialties of the health professionals conducting pre- and post-diagnosis consultations. RESULTS: The overall termination rate was 44% (49/111: 95% confidence interval: 35 to 54). Using multivariable logistic regression analysis, the only significant predictor of continuation of the pregnancy was the specialties of the health professionals conducting post-diagnosis counselling: the affected pregnancy was more likely to continue when post-diagnosis counselling involved only a genetics specialist (relative risk: 2.42 (1.14 to 5.92)). CONCLUSION: There is an association between whether or not a woman terminates a pregnancy affected by an unfamiliar fetal anomaly and the professional background of the health professional providing post-diagnostic counselling. The causal nature of this association remains to be determined.

Abortion, Eugenic↗
PubMed2002

Endothelial function is preserved in pregnant women with well-controlled type 1 diabetes.

OBJECTIVE: Pregnant women with diabetes mellitus have a higher incidence of adverse pregnancy outcomes. Vascular, and in particular, endothelial function may be significantly modified in diabetes resulting in impaired endothelium-dependent relaxation. This study aims to investigate endothelium-dependent relaxation in pregnant women with pre-existing type I diabetes mellitus. METHODS: Small arteries (mean luminal diameter approximately 295 microm) were isolated from biopsies of subcutaneous fat from pregnant women with pre-existing type I diabetes mellitus, non-diabetic pregnant women, and non-diabetic non-pregnant women. Endothelial and smooth muscle function were determined using wire myography, and the contributions of nitric oxide, vasodilator prostanoid and endothelial hyperpolarisation were studied using specific inhibitors. RESULTS: Arteries obtained from the diabetic pregnant women did not demonstrate any difference in either endothelial or smooth muscle function when compared with non-diabetic pregnant women. The contribution of nitric oxide to endothelium-dependent relaxation was approximately 20% in the pregnant women regardless of whether they were diabetic, and approximately 11% in the non-pregnant women. Endothelial hyperpolarisation appeared to contribute largely to vasorelaxation in human subcutaneous arteries, and was at least twice that of nitric oxide in pregnant women and fivefold greater in non-pregnant women. CONCLUSIONS: This study provides evidence that pregnant women with well-controlled pre-existing type 1 diabetes mellitus have both normal endothelial and smooth muscle function. Endothelium-dependent hyperpolarisation appears to play a large role in vascular relaxation in human subcutaneous resistance arteries. This study suggests that the problems associated with diabetic pregnancies are unlikely to be due to vascular dysfunction.

Adult↗