Retinoic acid can induce markers of endocrine transdifferentiation in pancreatic ductal adenocarcinoma: preliminary observations from an in vitro cell line model.

BACKGROUND AND HYPOTHESIS: The pancreatic ductal adenocarcinoma (HPAF) cells have a multipotent stem cell potential. It was hypothesised that all-trans-retinoic acid (atRA) can induce transdifferentiation of these cells into cells with an endocrine phenotype. MATERIAL AND METHODS: To explore this hypothesis, an in vitro system of cells was established. Some cells were treated with atRA at concentrations of 100 nmol/l (non-apoptosis-inducing) and 5 micromol/l (apoptosis-inducing) and harvested. Cells were examined for cell cycle kinetics, apoptosis (terminal deoxynucleotidyl transferase assay and p53 protein expression) and immunomorphological features of redifferentiation (MUC1 and DUPAN-2) and endocrine transdifferentiation (insulin, somatostatin, glucagon, neurone-specific enolase) by using immunoperoxidase staining methods. Levels of insulin, transforming growth factor (TGF) beta2, TGFalpha and epidermal growth factor receptor (EGFR) were measured by enzyme-linked immunosorbent assay (ELISA). The vehicle-treated cells served as a control group. RESULTS: When compared with untreated cells, cells treated with 100 nmol/l and 5 micromol/l atRA were observed to show (1) decreased proliferative activity (cpm) as indicated by decreased incorporation of thymidine labelled with hydrogen-3; (2) cell cycle arrest; (3) increased apoptotic activity associated with p53 protein overexpression; (4) upregulated expression of the transdifferentiation and redifferentiation markers; (5) morphological changes indicative of transdifferentiation (increased cell size and appearance of dendrites); (6) decreased production of EGFR; (7) upregulation of TGFalpha and TGFbeta2; and (8) increase in basal and glucose-induced insulin secretion. CONCLUSIONS: Functional endocrine transdifferentiation can be induced in HPAF lines by atRA. Further investigations are mandated to explore the underlying mechanisms of this transdifferentiation and to explore its in vivo extrapolation.

Is stored expressed breast milk an alternative for working Egyptian mothers?

Expression and storage of breast milk is way to maintain breastfeeding when mother and infant are separated, if the nutritional value can be conserved. Three expressed breast milk samples were collected from 61 healthy lactating mothers in Cairo, Egypt, for determination of total protein, fat, lactose and zinc content, as well as vitamins C, A and E concentrations. One sample was analysed immediately without storage, 1 after storage for 24 hours in a refrigerator (4 degrees C) and 1 after storage for 1 week in a home freezer (-4 degrees C to -8 degrees C). Refrigeration and freezing of breast milk caused a statistically significant decline in levels of vitamins C, A and E. Nevertheless, the values of all nutrients were still within the international reference ranges for mature breast milk.

Urinary iodine and other iodine deficiency indicators in a sample of school-age children in Egypt.

Sufficient data relating urinary iodine excretion in children to other iodine deficiency indicators are lacking in Egypt. We assayed urinary iodine concentration and serum levels of thyroid stimulating hormone (TSH), thyroglobulin, free triiodothyronine (T3) and free tetraiodothyronine in 99 school-aged Egyptian children. Goitre was found in 25 children. Median urinary iodine concentration was 70 microg/L. We found mild iodine deficiency (50-99 microg/L) in 60.6 % of the children and moderate to severe deficiency (< 50 microg/L) in 31.3%. The latter showed a high frequency of goitre and elevated mean serum free T3, TSH and thyroglobulin levels. Individual urinary iodine excretion rates vary, therefore these other indicators could help in screening for iodine deficiency at an individual level, especially in moderate to severe deficiency.