Trans-epidermal Transport and Storage of Calcium in Holthuisana transversa (Brachyura; Sundathelphusidae) During Premoult

Holthuisana transversa reabsorbs much of its exoskeletal calcium in the last 3 days before ecdysis and stores it in circulating granules in the haemocoel and in non-circulating granules in the subepidermal connective tissue. Calcium enters the epidermal cells from the moulting fluid, probably through their apical microvilli and is either incorporated into intracellular calcium granules or exits the cell via the basolateral membranes to be used in formation of two other granule types. Intracellular granules (0.4–2 μm long) form in large masses in the apical cytoplasm of the epidermal cells. They are formed as membrane-bound vesicles by the Golgi, and calcium and organic matrix material are added from the surrounding cytoplasm. As development proceeds, lamellae appear and calcium carbonate is deposited in the matrix. Granule masses move basally and are stored in the connective tissue. Calcium is also incorporated into extracellular large granules (0.8–3.8 μm long) which are formed in narrow intercellular channels between epidermal cells. A third granule type (small granules, 0.26 μm diameter) is formed in subepidermal connective tissue cells and released into the haemolymph in very large numbers. Calcium was identified in the two larger granule types using X-ray microanalysis and significant amounts of phosphorus and potassium were also present in the large granules. A model for ion cycling between the exoskeleton and granules is presented.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.