Diazoxide Promotes Oligodendrocyte Precursor Cell Proliferation and Myelination

Several clinical conditions are associated with white matter injury, including periventricular white matter injury (PWMI), which is a form of brain injury sustained by preterm infants. It has been suggested that white matter injury in this condition is due to altered oligodendrocyte (OL) development or death, resulting in OL loss and hypomyelination. At present drugs are not available that stimulate OL proliferation and promote myelination. Evidence suggests that depolarizing stimuli reduces OL proliferation and differentiation, whereas agents that hyperpolarize OLs stimulate OL proliferation and differentiation. Considering that the drug diazoxide activates K(ATP) channels to hyperpolarize cells, we tested if this compound could influence OL proliferation and myelination.Studies were performed using rat oligodendrocyte precursor cell (OPC) cultures, cerebellar slice cultures, and an in vivo model of PWMI in which newborn mice were exposed to chronic sublethal hypoxia (10% O(2)). We found that K(ATP) channel components Kir 6.1 and 6.2 and SUR2 were expressed in oligodendrocytes. Additionally, diazoxide potently stimulated OPC proliferation, as did other K(ATP) activators. Diazoxide also stimulated myelination in cerebellar slice cultures. We also found that diazoxide prevented hypomyelination and ventriculomegaly following chronic sublethal hypoxia.These results identify KATP channel components in OLs and show that diazoxide can stimulate OL proliferation in vitro. Importantly we find that diazoxide can promote myelination in vivo and prevent hypoxia-induced PWMI

Element characterization of african cuttlefish, Sepia bertheloti from the coastal waters off Qua Iboe River, Nigeria, using energy dispersive x-ray flourescence technique

Ten samples of African Cuttlefish, Sepia bertheloti, collected from the coastal waters off Qua Iboe River Nigeria, were analyzed using Energy Dispersive X-ray Fluorescence (EDXRF) analytical technique to determine their elemental composition. Eleven elements namely, CI, Sr, K, Ca, Br, Fe, Cu, Zn, Mn, Ni, and Se are identified and their relative concentration found. Of these elements, CI, Sr and Ca are present at the highest concentrations of 1.37 2.55 (1.86%), 1.15 - 2.10 (1.64%) and 0.09 - 0.43(0.31%), respectively. This is followed by K, Br. Fe, Zn, Cu, Mn, Ni and Se in decreasing order. Result further showed that at a daily consumption rate of 100 g/day, the values of the elements in the sea food are close to the US recommended dietary reference intakes for people of different age groups. These elements are of great nutritional value for proper and healthy growth of humans. The accuracy and precision of the technique were assured by analyzing the BCR referencematerials BCR 185 (bovine liver), and BCR 186 (pig kidney)

Canine trypanosomosis: Clinical observations and morphological pathology associated with natural infection of Trypanosoma congolense in exotic breeds of dog in Abeokuta, Nigeria

Clinical and pathological aspects of canine trypanosomosis were determined in naturally infected dogs presented to the Veterinary Teaching Hospital, Federal University of Agriculture, Abeokuta, at different times between 2012 and 2013. The breeds, sexes, ages and body weights of the dogs were recorded.  Clinical signs were observed. Blood samples were collected to determine their packed cell volumes  (PCVs) and parasitaemia. Post-mortem examinations were carried out on 6 dogs that died of the disease and tissue samples were collected and fixed in 10% buffered formalin for histopathology. Trypanosoma species was characterized using polymerase chain reaction. Trypansoma species detected by microscopy was confirmed as T. congolense savannah sub-type by PCR. Clinically, the dogs were anorexic, lethargic and showed lymphadenopathy. Their body temperatures ranged from 40-41.6oC,  Respiratory rates were 28-34/minute, 4 out of 6 cases examined at post-mortem showed epistaxis. The gross lesions were pale mucous membranes, severe pulmonary congestions, haemorrhages and oedema (4/6), marked hydrothorax measuring 1-2 litres (5/6), misshapen heart with petechial and ecchymotic haemorrhages in the epicardium (4/6), severely enlarged and icteric livers and splenomegaly. The intestinal mucous membranes were haemorrhagic (2/6), the kidneys were pale and the testes were haemorrhagic (2/6). Microscopic lesions were severe pulmonary congestion, haemorrhages, oedema and infiltration by inflammatory cells, severe haemorrhagic myocarditis, hyperplastic lymphodenopathy, varying degree of degeneration and necrosis with inflammatory reactions in the lungs, hearts, livers,  spleens and kidneys. The liver sinusoids were dilated and the hepatocytes show varying degree of fatty change. In some cases, hepatocytes were atrophic. In all the six cases, Trypanosome species were characterized as T. congolense savannah type. The pathogenicity of trypanosomes in dogs was discussed.Keywords: trypanosomosis, clinical signs, parasitaemia, pathology, dogs. rhodesense