Effect of forkhead box O1 (FOXO1) on beta cell development in the human fetal pancreas.

AIMS/HYPOTHESIS: Recent studies have demonstrated that in adult murine beta cells the forkhead box O1 (FOXO1) transcription factor regulates proliferation and stress resistance. However, the role of FOXO1 during pancreatic development remains largely unknown. The present study aimed to characterise the expression of the FOXO1 transcription factor in the early to mid-gestation human fetal pancreas and to understand its role in islet cell development. METHODS: Human (8-21 week fetal age) pancreases were examined using immunohistological, quantitative RT-PCR and western blotting. Isolated human (18-21 week) fetal islet epithelial cell clusters were treated with insulin or glucose, or transfected with FOXO1 small interfering RNA (siRNA). RESULTS: Nuclear and cytoplasmic FOXO1 were widely produced during human fetal endocrine pancreatic development, co-localising in cells with the transcription factors pancreatic and duodenal homeobox 1 (PDX-1) and neurogenin 3 (NGN3) as well as cytokeratin 19 (CK19), insulin and glucagon. Treatment with exogenous insulin (50 nmol/l) induced the nuclear exclusion of FOXO1 in both cytokeratin 19 (CK19)(+) (p < 0.01) and insulin(+) cells (p < 0.05) in parallel with increased phospho-Akt (p < 0.05) production. siRNA knockdown of FOXO1 significantly increased the number of NGN3(+) (p < 0.01) and NK6 homeobox 1 (NKX6-1)(+) (p < 0.05) cells in parallel with increases in insulin gene expression (p < 0.03) and C-peptide(+) cells (p < 0.05) and reduced levels of hairy and enhancer of split 1 (HES1) (p < 0.01). CONCLUSIONS/INTERPRETATION: Our results indicate that FOXO1 may negatively regulate beta cell differentiation in the human fetal pancreas by controlling critical transcription factors, including NGN3 and NKX6-1. These data suggest that the manipulation of FOXO1 levels may be a useful tool for improving cell-based strategies for the treatment of diabetes.

High risk pregnancy: detection and management.

Risk in pregnancy relates to events which lead to perinatal morbidity and mortality. Numerous risk scoring systems have been devised to bring attention to risk factors so that problems can be prevented, identified and treated. However, by carrying out very few fundamental assessments at regular antenatal office visits: checking blood pressure, testing urine for protein, measuring the symphysis to fundus height and carefully establishing the expected date of confinement during the first trimester, the principal causes of perinatal morbidity and mortality-intrauterine growth retardation, prematurity, congenital anomalies, infection, abruptio placentae and meconium aspiration-can be identified and treated. Appropriate perinatal management of the very premature fetus/neonate (less than 34 weeks gestation) is a critical factor which will influence outcome. Whenever possible the mother should be transferred to a centre equipped and staffed for all necessary intrapartum and neonatal care, to minimize the risk of adverse outcome: postnatal transfer of the deteriorating, sick, small neonate is at best hazardous.

Factors associated with immediate abortion complications.

OBJECTIVE: To identify factors associated with increased risk of immediate complications from induced abortion. DESIGN: Retrospective analysis of a provincial database. SETTING: All Ontario general hospitals in which abortions are performed and all free-standing abortion clinics in Ontario. POPULATION: Women in Ontario aged 15 to 44 years who underwent an induced abortion in the province (without concurrent sterilization) between Jan. 1, 1992, and Dec. 31, 1993. OUTCOME MEASURES: Recording of complications at the time of the procedure, gestational age, type of procedure, place of abortion (hospital or clinic), and patient's age, parity and history of previous abortion (spontaneous or induced). RESULTS: During the study period 83 469 abortions were performed that met our inclusion criteria. Immediate complications were reported in 571 cases (0.7%). Multivariate logistic regression analysis revealed that, after other variables were controlled for, the patient's age, parity and history of previous abortions (spontaneous or induced) were not significant risk factors for immediate complications; however, gestational age, method of abortion and place of abortion were significant risk factors (p < 0.001). The odds ratio (OR) for having a complication from abortion was 1.3 (95% confidence interval [CI] 1.02 to 1.63) between 9 and 12 weeks, compared with having one after abortion at 9 weeks or earlier, and increased to 3.3 (95% CI 2.23 to 5.00) after abortion between 17 and 20 weeks. Compared with surgical dilatation and curettage (D&C), instillation of saline and instillation of prostaglandins were more likely to be associated with immediate complications (OR 24.0, 95% CI 13.22 to 43.70, and OR 11.7, 95% CI 6.43 to 21.18, respectively), whereas both suction D&C and insertion of a laminaria tent were less likely to be associated with immediate complications (OR 0.4, 95% CI 0.26 to 0.67, and OR 0.3, 95% CI 0.19 to 0.52, respectively). Compared with women who had an abortion in a free-standing clinic, the risk for immediate complications was greater among those who had an abortion in a hospital, especially a teaching hospital (OR 1.9, 95% CI 1.38 to 2.58), a nonteaching hospital with 200 to 399 acute care beds (OR 3.1, 95% CI 2.27 to 4.21) and a nonteaching hospital with fewer than 200 acute care beds (OR 5.9, 95% CI 4.04 to 8.64). CONCLUSION: The risk of immediate complications from induced abortion is very low. Unlike in previous studies, the woman's age, parity and history of previous spontaneous or induced abortions were not found to be risk factors. However, advancing gestational age and procedures involving instillation of saline or prostaglandins were predictive factors of immediate complications.

Cellular distribution of enzymes involved in phosphatidylcholine synthesis in developing rat lung.

The incorporation of radioactive choline into phosphatidylcholine and disaturated phosphatidylcholine in rat lung slices increased markedly before term and peaked after birth. The specific activity of cholinephosphate cytidylyltransferase in the microsomal fraction increased before birth but fell after delivery. The specific activity of this enzyme in the cytosol showed a marked increased at birth. The developmental profile for the total cytosolic activity per gram lung was similar to the pattern observed with choline incorporation. Although the specific activity of cholinephosphotransferase in the whole homogenate remained relatively constant throughout pulmonary maturation, there was a marked increase in the specific activity of this enzyme in the microsomal fraction at term. Similar findings were obtained with the microsomal marker NADPH-cytochrome c reductase. The basis of this disparity in specific activity profiles is being investigated further. The specific activity of lysophosphatidylcholine:lysophosphatidylcholine transacylase in rat lung homogenates increased during gestation but rose a further 10-fold between day 3 after birth and the adult. The specific activity of lysophosphatidylcholine:palmitoyl-CoA acyltransferase remained relatively constant throughout development. At term, the specific activity of the acylation enzyme was 10- to 15-fold greater than the specific activity of the transacylation enzyme. These observations are consistent with previous studies indicating that the accumulation of phosphatidylcholine and dipalmitoyl phosphatidylcholine during the perinatal period may be due to alterations in the activity of cholinephosphate cytidylyltransferase. Cholinephosphotransferase could also play a regulatory role. The formation of dipalmitoyl phosphatidylcholine appears to occur via the acylation, rather than the transacylation pathway.