MR

Mass drug administration (MDA) programmes against Onchocerca volvulus use ivermectin (IVM) which targets microfilariae (MF), the worm's offspring. Most infected individuals are hyporesponsive and present regulated immune responses despite high parasite burden. Recently, with MDA programmes, the existence of amicrofilaridermic (a-MF) individuals has become apparent but little is known about their immune responses. Within this immunoepidemiological study, we compared parasitology, pathology and immune profiles in infection-free volunteers and infected individuals that were MF+ or a-MF. The latter stemmed from villages in either Central or Ashanti regions of Ghana which, at the time of the study, had received up to eight or only one round of MDA respectively. Interestingly, a-MF patients had fewer nodules and decreased IL-10 responses to all tested stimuli. On the other hand, this patient group displayed contrary IL-5 profiles following in vitro stimulation or in plasma and the dampened response in the latter correlated to reduced eosinophils and associated factors but elevated neutrophils. Furthermore, multivariable regression analysis with covariates MF, IVM or the region (Central vs. Ashanti) revealed that immune responses were associated with different covariates: whereas O. volvulus-specific IL-5 responses were primarily associated with MF, IL-10 secretion had a negative correlation with times of individual IVM therapy (IIT). All plasma parameters (eosinophil cationic protein, IL-5, eosinophils and neutrophils) were highly associated with MF. With regards to IL-17 secretion, although no differences were observed between the groups to filarial-specific or bystander stimuli, these responses were highly associated with the region. These data indicate that immune responses are affected by both, IIT and the rounds of IVM MDA within the community. Consequently, it appears that a lowered infection pressure due to IVM MDA may affect the immune profile of community members even if they have not regularly participated in the programmes

Evolution of Microstructure and Texture during Severe Cold Rolling and Annealing Of Al-2.5%Mg and Al-2.5%Mg-0.2%Sc Alloys

Evolution of microstructure and texture in Al-2.5%Mg and Al- 2.5%Mg-0.2%Sc alloys during severe cold rolling and subsequent annealing was studied using electron back scatter diffraction (EBSD). These alloys were first thermo-mechanically processed to sheets of average thickness (~lmm) with well recrystallized microstructures. These sheets were subsequently severely cold- rolled up to an equivalent strain of 4.32 using a combination of Accumulative Roll Bonding and conventional cold-rolling. The deformed alloys were subjected to isochronal annealing treatment for one hour in a wide temperature range. Development of Ultrafine lamellar microstructure subdivided by high angle grain boundaries (HAGB) and pure metal or copper type texture was observed in both the alloys during deformation. Al-Mg-Sc consistently showed higher hardness as compared to the Al-Mg. Al-Mg recrystallized around ~ 2500C but in Al-Mg-Sc the recrystallization was greatly delayed up to 500°C and the deformation texture components were retained during annealing. The differences in the recrystallization behavior of two materials were discussed with regard to the deformation microstructure and presence of fine precipitate