TLR2/MyD88/NF-κB Pathway, Reactive Oxygen Species, Potassium Efflux Activates NLRP3/ASC Inflammasome during Respiratory Syncytial Virus Infection

Human respiratory syncytial virus (RSV) constitute highly pathogenic virus that cause severe respiratory diseases in newborn, children, elderly and immuno-compromised individuals. Airway inflammation is a critical regulator of disease outcome in RSV infected hosts. Although “controlled” inflammation is required for virus clearance, aberrant and exaggerated inflammation during RSV infection results in development of inflammatory diseases like pneumonia and bronchiolitis. Interleukin-1β (IL-1β) plays an important role in inflammation by orchestrating the pro-inflammatory response. IL-1β is synthesized as an immature pro-IL-1β form. It is cleaved by activated caspase-1 to yield mature IL-1β that is secreted extracellularly. Activation of caspase-1 is mediated by a multi-protein complex known as the inflammasome. Although RSV infection results in IL-1β release, the mechanism is unknown. Here in, we have characterized the mechanism of IL-1β secretion following RSV infection. Our study revealed that NLRP3/ASC inflammasome activation is crucial for IL-1β production during RSV infection. Further studies illustrated that prior to inflammasome formation; the “first signal” constitutes activation of toll-like receptor-2 (TLR2)/MyD88/NF-κB pathway. TLR2/MyD88/NF-κB signaling is required for pro-IL-1β and NLRP3 gene expression during RSV infection. Following expression of these genes, two “second signals” are essential for triggering inflammasome activation. Intracellular reactive oxygen species (ROS) and potassium (K+) efflux due to stimulation of ATP-sensitive ion channel promote inflammasome activation following RSV infection. Thus, our studies have underscored the requirement of TLR2/MyD88/NF-κB pathway (first signal) and ROS/potassium efflux (second signal) for NLRP3/ASC inflammasome formation, leading to caspase-1 activation and subsequent IL-1β release during RSV infection

Seasonal variations in the levels of heavy metals in river waters of Ebonyi state, Nigeria

Concentrations of Cadmium (Cd), Chromium (Cr), Mercury (Hg), Copper (Cu), Zinc (Zn), Lead (Pb) and Iron (Fe) were sampled four rivers in Ebonyi State, Nigeria across two seasons to determine their degree of pollution and portability considering the incidental industrial, agricultural and other activities in the area. Mean concentrations of iron were significantly (

Studies on pest infestation of commercial samples of cowpeas and maize Marketed in Owerri, Imo State, Nigeria

Samples of different varieties of brown beans, Vigna unguiculata and white maize, Zea mays randomly purchased from two open markets in Owerri, Imo State were studied for pest infestation. The grains were examined with x2 magnification hand lens for the eggs, larvae and adults of the pests. Callosobruchus maculates (Olivier) and Sitophilus zeamais (Motsch) were identified as insect pests infesting beans and maize respectively. On the overall, 43.3% of 7565 cowpea and 30.8% of 4640 of maize grains respectively were infested. Eggs, larvae, pupae and adults of the insect pests were recovered from both the beans and maize samples. In beans, eggs of C. maculates were found only on the pericarp while the larvae, pupae and adults were recovered from both the pericarp and from within the endosperm of the seeds. In the maize, the eggs, larvae and pupae of S. zeamais were located in the endosperm only, while the adults were found in both the endosperm and the outer surfaces of the grains. Weight loss as an index of degree of damage to the samples ranged from 23.3% to 35.7% in beans and 19.3% to 55.7% in maize. Weight loss in both the infested beans and maize increased with increase in the number of emergence holes. Public health implications of the insect infestation of the stored products such as reduction in nutritive value and accumulation of undesirable residues were discussed. Improved storage and pest control techniques are recommended. Keywords: pest, infestation, cowpea, maize, Nigeria International Journal of Natural and Applied Sciences Vol. 1(1) 2005: 5-

Formulated feed preference for survival and optimal growth of Bulinus species reared in the laboratory

Seventy-seven Bulinus snail species were fed for eight weeks with eleven diets consisting of different feed-formulations and vegetables. Snails reared exclusively on grower’s mash, corn fibre meal and fish meal did not survive for up to two weeks. The result from this investigation indicatesthat there isno signiicant difference in body growh gain between lettuce + blood meal, lettuce +groundnut fibre meal, blood meal, lettuce and cabbage. But they showed significant dfference withlettuce + corn fibre meal and lettuce + fish meal. It is therefore recommended that in a situation where lettuce which is well known as the snail’s food is not available as during the peak of rainy season, feeds like blood meal and cabbage can be used as viable substitutes for rearing experimental Bulinus snail species in the laboratory. Also, lettuce + blood meal has been shown bythis study as the best feed formulation for the optimal growth and development of Bulinus sp in thelaboratory.Keywords: Bulinus snail, Lettuce, Blood meal, Dietary formulations, Surviva

Prevalence of pediculosis in selected rural areas of Imo State, Nigeria

A study of the prevalence of Pediculus capitis (Head lice) was carried out at some selected primary schools in the rural areas of Imo-State, Nigeria. Infestation was diagnosed by direct inspection of the hair and scalp for the presence of adult head lice, nymph or nits (eggs). A total number of 2080pupils were examined; out of which 208 (10%) were infected with head lice. The prevalence varied across the communities, sex and age groups. In all the schools surveyed, female pupils had the highest prevalence of pediculosis. Infestation also increased with age in both male and female pupils. The public health significance in relation to the infestation of head lice on primary school pupils was highlighted. Possible measure for controlling and preventing pediculosis like initiating a screening program by school administrators in the first week school resumption in September are discussed.Keywords: Pediculosis, head lice, school pupils, rural areas, Nigeri

Evaluation of Bacterial and Parasitic Load of Clarias species from River Niger and an artificial habitat in Onitsha, Anambra State, Nigeria

The bacterial and parasitic load of Clarias gariepinus fishes collected from a fish pond and River Niger in Onitsha, Anambra State were studied. A total of 25 apparently healthy and diseased fishes comprising of 13 (2 diseased and 11 healthy pond fishes) and 12 apparently healthy fishes from River Niger were examined. The skin, gills and intestine of the fishes were examined. The findings of bacteriological examinations revealed that Staphylococcus Species (sp)Enterobacter sp , Pseudomonas sp, Escherichia coli, Streptococcus feacalis, Proteus sp, Aeromonas sp , Vibrio sp and Salmonella sp were present in the skin, gills and intestine of the fishes examined. Prevalence of bacteria in the different parts of the fishes were: Intestine > gills and skins and also gills > skin in two habitats. Parasitic examination of the fishes revealed the presence of: Entamoeba sp, Trichodina sp, Ichthiopthrius sp, Gyrodactylus sp, and Neobenedenia melleni. Entamoeba sp (84.0%) was the most prevalent parasite encountered while the least was Gyrodactylus species and Neobenedenia species (4.0%) respectively. Comparative analysis of the samples from pond and river showed that Pond fishes haboured more bacteria and parasites than River Niger fishes. This study has shown that apparently healthy and diseased fishes from artificial culture systems and natural water habitat habour bacterial and parasitic organisms capable of infecting humans.Keywords: Clarias gariepinus, Proteus sp, Entamoeba sp, gills and Trichodina sp.Nigerian Journal of Parasitology, Vol. 32 [1] March 2011, pp.117-12