The Experts below are selected from a list of 77886 Experts worldwide ranked by ideXlab platform
Minja Gerber - One of the best experts on this subject based on the ideXlab platform.
-
Formulation of Natural Oil Nano-Emulsions for the Topical Delivery of Clofazimine, Artemisone and Decoquinate
Pharmaceutical Research, 2018Co-Authors: Cornel Burger, Marique Aucamp, Jan Du Preez, Richard K. Haynes, Andile Ngwane, Jeanetta Du Plessis, Minja GerberAbstract:Purpose The aim of this study was to formulate nano-emulsions comprising natural oils and the active pharmaceutical ingredients (Apis) clofazimine (CLF), artemisone (ATM) and decoquinate (DQ) in order to determine effectiveness of the nano-emulsions for topical delivery of the Apis. The Apis alone do not possess suitable physicochemical properties for topical drug delivery. Methods Nano-emulsions were formulated with olive and safflower oils encapsulating the Apis. Skin diffusion and tape stripping studies were performed. By using the lactate dehydrogenase (LDH) assay, in vitro toxicity studies were carried out on immortalized human keratinocytes (HaCaT) cell line to determine cytotoxicities due to the Apis and the nano-emulsions incorporating the Apis. Results The nano-emulsions were effective in delivering the Apis within the stratum corneum-epidermis and the epidermis-dermis, were non-cytotoxic towards HaCaT cell lines ( p
-
formulation of natural oil nano emulsions for the topical delivery of clofazimine artemisone and decoquinate
Pharmaceutical Research, 2018Co-Authors: Cornel Burger, Marique Aucamp, Richard K. Haynes, Andile Ngwane, Jeanetta Du Plessis, Jan L Du Preez, Minja GerberAbstract:The aim of this study was to formulate nano-emulsions comprising natural oils and the active pharmaceutical ingredients (Apis) clofazimine (CLF), artemisone (ATM) and decoquinate (DQ) in order to determine effectiveness of the nano-emulsions for topical delivery of the Apis. The Apis alone do not possess suitable physicochemical properties for topical drug delivery. Nano-emulsions were formulated with olive and safflower oils encapsulating the Apis. Skin diffusion and tape stripping studies were performed. By using the lactate dehydrogenase (LDH) assay, in vitro toxicity studies were carried out on immortalized human keratinocytes (HaCaT) cell line to determine cytotoxicities due to the Apis and the nano-emulsions incorporating the Apis. The nano-emulsions were effective in delivering the Apis within the stratum corneum-epidermis and the epidermis-dermis, were non-cytotoxic towards HaCaT cell lines (p < 0.05) and inhibited Mycobacterium tuberculosis in vitro. Natural oil nano-emulsions successfully deliver CLF, ATM and DQ and in principle could be used as supplementary topical treatment of cutaneous tuberculosis (CTB).
Panuwan Chantawannakul - One of the best experts on this subject based on the ideXlab platform.
-
impact of nosema ceranae and nosema Apis on individual worker bees of the two host species Apis cerana and Apis mellifera and regulation of host immune response
Journal of Insect Physiology, 2018Co-Authors: Chainarong Sinpoo, Terd Disayathanoowat, Sasiprapa Krongdang, Panuwan ChantawannakulAbstract:Nosema Apis and Nosema ceranae are obligate intracellular microsporidian parasites infecting midgut epithelial cells of host adult honey bees, originally Apis mellifera and Apis cerana respectively. Each microsporidia cross-infects the other host and both microsporidia nowadays have a worldwide distribution. In this study, cross-infection experiments using both N. Apis and N. ceranae in both A. mellifera and A. cerana were carried out to compare pathogen proliferation and impact on hosts, including host immune response. Infection by N. ceranae led to higher spore loads than by N. Apis in both host species, and there was greater proliferation of microsporidia in A. mellifera compared to A. cerana. Both N. Apis and N. ceranae were pathogenic in both host Apis species. N. ceranae induced subtly, though not significantly, higher mortality than N. Apis in both host species, yet survival of A. cerana was no different to that of A. mellifera in response to N. Apis or N. ceranae. Infections of both host species with N. Apis and N. ceranae caused significant up-regulation of AMP genes and cellular mediated immune genes but did not greatly alter apoptosis-related gene expression. In this study, A. cerana enlisted a higher immune response and displayed lower loads of N. Apis and N. ceranae spores than A. mellifera, suggesting it may be better able to defend itself against microsporidia infection. We caution against over-interpretation of our results, though, because differences between host and parasite species in survival were insignificant and because size differences between microsporidia species and between host Apis species may alternatively explain the differential proliferation of N. ceranae in A. mellifera.
-
infections of nosema ceranae in four different honeybee species
Journal of Invertebrate Pathology, 2010Co-Authors: Veeranan Chaimanee, Natapot Warrit, Panuwan ChantawannakulAbstract:The microsporidium Nosema ceranae is detected in honeybees in Thailand for the first time. This endoparasite has recently been reported to infect most Apis mellifera honeybee colonies in Europe, the US, and parts of Asia, and is suspected to have displaced the endemic endoparasite species, Nosema Apis, from the western A. mellifera. We collected and identified species of microsporidia from the European honeybee (A. mellifera), the cavity nesting Asian honeybee (Apis cerana), the dwarf Asian honeybee (Apis florea) and the giant Asian honeybee (Apis dorsata) from colonies in Northern Thailand. We used multiplex PCR technique with two pairs of primers to differentiate N. ceranae from N. Apis. From 80 A. mellifera samples, 62 (77.5%) were positively identified for the presence of the N. ceranae. Amongst 46 feral colonies of Asian honeybees (A. cerana, A. florea and A. dorsata) examined for Nosema infections, only N. ceranae could be detected. No N. Apis was found in our samples. N. ceranae is found to be the only microsporidium infesting honeybees in Thailand. Moreover, we found the frequencies of N. ceranae infection in native bees to be less than that of A. mellifera.
Zachary Y. Huang - One of the best experts on this subject based on the ideXlab platform.
-
comparative virulence and competition between nosema Apis and nosema ceranae in honey bees Apis mellifera
Journal of Invertebrate Pathology, 2015Co-Authors: Meghan O Milbrath, Leellen F. Solter, David R. Tarpy, Toan Van Tran, Wei Fong Huang, Frank R Lawrence, Zachary Y. HuangAbstract:Abstract Honey bees (Apis mellifera) are infected by two species of microsporidia: Nosema Apis and Nosema ceranae. Epidemiological evidence indicates that N. ceranae may be replacing N. Apis globally in A. mellifera populations, suggesting a potential competitive advantage of N. ceranae. Mixed infections of the two species occur, and little is known about the interactions among the host and the two pathogens that have allowed N. ceranae to become dominant in most geographical areas. We demonstrated that mixed Nosema species infections negatively affected honey bee survival (median survival = 15–17 days) more than single species infections (median survival = 21 days and 20 days for N. Apis and N. ceranae, respectively), with median survival of control bees of 27 days. We found similar rates of infection (percentage of bees with active infections after inoculation) for both species in mixed infections, with N. Apis having a slightly higher rate (91% compared to 86% for N. ceranae). We observed slightly higher spore counts in bees infected with N. ceranae than in bees infected with N. Apis in single microsporidia infections, especially at the midpoint of infection (day 10). Bees with mixed infections of both species had higher spore counts than bees with single infections, but spore counts in mixed infections were highly variable. We did not see a competitive advantage for N. ceranae in mixed infections; N. Apis spore counts were either higher or counts were similar for both species and more N. Apis spores were produced in 62% of bees inoculated with equal dosages of the two microsporidian species. N. ceranae does not, therefore, appear to have a strong within-host advantage for either infectivity or spore growth, suggesting that direct competition in these worker bee mid-guts is not responsible for its apparent replacement of N. Apis.
-
infectivity and virulence of nosema ceranae and nosema Apis in commercially available north american honey bees
Journal of Invertebrate Pathology, 2015Co-Authors: Leellen F. Solter, Katherine A Aronstein, Zachary Y. HuangAbstract:Nosema ceranae infection is ubiquitous in western honey bees, Apis mellifera, in the United States and the pathogen has apparently replaced Nosema Apis in colonies nationwide. Displacement of N. Apis suggests that N. ceranae has competitive advantages but N. ceranae was significantly less infective and less virulent than N. Apis in commercially available lineages of honey bees in studies conducted in Illinois and Texas. At 5 days post eclosion, the most susceptible age of adult bees tested, the mean ID50 for N. Apis was 359 spores compared to 3217 N. ceranae spores, a nearly 9-fold difference. Infectivity of N. ceranae was also lower than N. Apis for 24-h and 14-day worker bees. N. ceranae was less infective than reported in studies using European strains of honey bees, while N. Apis infectivity, tested in the same cohort of honey bees, corresponded to results reported globally from 1972 to 2010. Mortality of worker bees was similar for both pathogens at a dosage of 50 spores and was not different from the uninfected controls, but was significantly higher for N. Apis than N. ceranae at dosages ⩾500 spores. Our results provide comparisons for evaluating research using different ages of bees and pathogen dosages and clarify some controversies. In addition, comparisons among studies suggest that the mixed lineages of US honey bees may be less susceptible to N. ceranae infections than are European bees or that the US isolates of the pathogen are less infective and less virulent than European isolates.
Nallahalli Shivarajegowda Surendra - One of the best experts on this subject based on the ideXlab platform.
-
Comparative morphometric studies of the sting apparatus of the worker bees of four different Apis species (Apis dorsata, Apis mellifera, Apis cerana and Apis florea)
Journal of Apicultural Research, 2013Co-Authors: Nallahalli Shivarajegowda Surendra, Gopasandra Narayanappa Jayaram, Muniswamy Reddy Shankara Reddy, Hemagirigowda RavikumarAbstract:SummaryTwo glands associated with the sting apparatus of worker honey bees produce venom. The aim of this study was to analyse the size and morphometrics of the sting apparatus of worker bees of fo...
-
antimicrobial activity of crude venom extracts in honeybees Apis cerana Apis dorsata Apis florea tested against selected pathogens
African Journal of Microbiology Research, 2011Co-Authors: Nallahalli Shivarajegowda Surendra, Gopasandra Narayanappa Jayaram, M S ReddyAbstract:Antimicrobial activity of crude venom extracts from different honeybee species was tested against selected pathogens. Toxicity of bee venom is known to man since ages, which varies from mild inflammations to death. Bee venom is synthesized in the venom glands of worker bees and queen and is stored in the venom sac. In the present study the toxic potentialities of honeybee venom pertaining to different honeybee species Apis cerana, Apis dorsata and Apis florea was carried out in vitro on selected species of bacteria and fungi. The selected bacteria and fungal species were Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Xanthomonas subtilis, Proteus vulgaris, Salmonella typhimurium and Candida albicans. They were collected from St. John Medical College, Bangalore. The antimicrobial activity of different species of Apis bee venom (ABV) was studied by Disc Diffusion Assay. Minimal inhibitory concentration (MIC) was determined using Broth dilution method at lowest dilution (0.5 mg/ml). Bacterial growth was assessed by the measurement of inhibitory zone. The order of susceptibility of the pathogens against the ABV recorded was: A. cerana > Apis dorsata> Apis florea.The results showed that, ABV has significant antimicrobial effects and could be a potential alternative antibiotic. Key words: Bee venom, Apis species, broth dilution, inhibitory zone, bacteria, fungi.
Hemagirigowda Ravikumar - One of the best experts on this subject based on the ideXlab platform.
-
Comparative morphometric studies of the sting apparatus of the worker bees of four different Apis species (Apis dorsata, Apis mellifera, Apis cerana and Apis florea)
Journal of Apicultural Research, 2013Co-Authors: Nallahalli Shivarajegowda Surendra, Gopasandra Narayanappa Jayaram, Muniswamy Reddy Shankara Reddy, Hemagirigowda RavikumarAbstract:SummaryTwo glands associated with the sting apparatus of worker honey bees produce venom. The aim of this study was to analyse the size and morphometrics of the sting apparatus of worker bees of fo...
