Evidence of co-infection of chikungunya and densonucleosis viruses in C6/36 cell lines and laboratory infected Aedes aegypti (L.) mosquitoes

<p>Abstract</p> <p>Background</p> <p>Densonucleosis viruses are the etiological agents of insect's disease. We have reported the isolation of densovirus from India and its distribution among the natural populations of <it>Aedes aegypti </it>mosquitoes across the country. Since densonucleosis virus persistently infects mosquito populations, and is demonstrated to negatively affect multiplication of dengue virus in <it>Aedes albopictus</it>, it would be interesting to study if this virus has a role in determining the susceptibility of the vector mosquito <it>Ae. aegypti </it>to chikugunya virus.</p> <p>Methods</p> <p>Mosquito cell lines and adult <it>Ae. aegypti </it>mosquitoes infected with densovirus were superinfected with Chikungunya virus and both the viruses were quantitated by determining their genomic copy number by real time amplification. Comparison was made between the log of genomic copy numbers of the viruses in the presence and absence of each other.</p> <p>Results</p> <p>The log of copy number of the viruses did not vary due to co-infection. Even though the RNA copy number of chikungunya virus increased over the period of time, no change was observed in the RNA copy number between the control and the co-infected group on any given day. Similarly, DNA copy number of densovirus also remained unchanged between the control and the co-infected groups.</p> <p>Conclusion</p> <p>Chikungunya virus neither stimulates the replication of densovirus nor is its own replication suppressed due to co-infection. <it>Ae. aegypti </it>mosquitoes with densovirus infection were as susceptible to infection by chikungunya virus as the uninfected mosquitoes.</p

Absence of knockdown resistance suggests metabolic resistance in the main malaria vectors of the Mekong region

<p>Abstract</p> <p>Background</p> <p>As insecticide resistance may jeopardize the successful malaria control programmes in the Mekong region, a large investigation was previously conducted in the Mekong countries to assess the susceptibility of the main malaria vectors against DDT and pyrethroid insecticides. It showed that the main vector, <it>Anopheles epiroticus</it>, was highly pyrethroid-resistant in the Mekong delta, whereas <it>Anopheles minimus sensu lato </it>was pyrethroid-resistant in northern Vietnam. <it>Anopheles dirus sensu stricto </it>showed possible resistance to type II pyrethroids in central Vietnam. <it>Anopheles subpictus </it>was DDT- and pyrethroid-resistant in the Mekong Delta. The present study intends to explore the resistance mechanisms involved.</p> <p>Methods</p> <p>By use of molecular assays and biochemical assays the presence of the two major insecticide resistance mechanisms, knockdown and metabolic resistance, were assessed in the main malaria vectors of the Mekong region.</p> <p>Results</p> <p>Two FRET/MCA assays and one PCR-RFLP were developed to screen a large number of <it>Anopheles </it>populations from the Mekong region for the presence of knockdown resistance (<it>kdr</it>), but no <it>kdr </it>mutation was observed in any of the study species. Biochemical assays suggest an esterase mediated pyrethroid detoxification in <it>An. epiroticus </it>and <it>An. subpictus </it>of the Mekong delta. The DDT resistance in <it>An. subpictus </it>might be conferred to a high GST activity. The pyrethroid resistance in <it>An. minimus s.l</it>. is possibly associated with increased detoxification by esterases and P450 monooxygenases.</p> <p>Conclusion</p> <p>As different metabolic enzyme systems might be responsible for the pyrethroid and DDT resistance in the main vectors, each species may have a different response to alternative insecticides, which might complicate the malaria vector control in the Mekong region.</p

Solubility prediction of satranidazole in aqueous N,N-dimethylformamide mixtures using extended hildebrand solubility approach

The solubility of satranidazole in several water-N,N-dimethylformamide mixtures was analysed in terms of solute-solvent interactions and data were treated on the basis of extended Hildebrand solubility approach. The solubility profile of satranidazole in water-N,N-dimethylformamide mixtures shows a curve with a solubility maxima well above the ideal solubility of drug. This is attributed to solvation of the drug with the water-N,N-dimethylformamide mixture, and indicates that the solute-solvent interaction energy (W) is larger than the geometric mean (δ1δ2 ) of regular solution theory. The new approach provides an accurate prediction of solubility once the interaction energy (W ) is obtained. In this case, the energy term is regressed against a polynomial in δ1 of the binary solvent mixture. A quartic expression of W in terms of solvent solubility parameter was found for predicting the mole fraction solubility of satranidazole in the studied mixtures. The method has potential usefulness in preformulation and formulation studies during which solubility prediction is important for drug design

Non-enzymatic glycation of proteins: A cause for complications in diabetes

337-344Diabetes mellitus is one of the most common non-communicable diseases, and is the fifth leading cause of death in most of the developed countries. It can affect nearly every organ and system in the body and may result in blindness, end stage renal disease, lower extremity amputation and increase risk of stroke, ischaemic heart diseases and peripheral vascular disease. Hyperglycemia in diabetes causes non-enzymatic glycation of free amino groups of proteins (of lysine residues) and leads to their structural and functional changes, resulting in complications of the diabetes. Glycation of proteins starts with formation of Shiff’s base, followed by intermolecular rearrangement and conversion into Amadori products. When large amounts of Amadori products are formed, they undergo cross linkage to form a heterogeneous group of protein-bound moieties, termed as advanced glycated end products (AGEs). Rate of these reactions are quite slow and only proteins with large amounts of lysine residues undergo glycation with significant amounts of AGEs. The formation of AGEs is a irreversible process, causing structural and functional changes in protein leading to various complications in diabetes like nephropathy, retinopathy, neuropathy and angiopathy. The present review discusses about role of glycation in various complications of diabetes

Experimental transmission of Chikungunya virus by Anopheles stephensi mosquitoes

The Ades aegypti mosquito has been considered the principal vector of Chikungunya (CHIK) virus. As CHIK epidemics usually occur in urban regions and Anopheles stephensi is another highly endophilic and anthropophilic mosquito, there is a very high probability of this mosquito to feed on CHIK virus-infected patients, to pick up and transmit the virus. Therefore the present study was conducted to test the CHIK virus transmission capability for the A. stephensi mosquito. The obtained results showed that this mosquito species is capable of transmitting CHIK virus. It is surmised that during any epidemic of febrile illness CHIK virus isolation attempts should also be made from this mosquito species