Bombyx mori nucleopolyhedrovirus (BmNPV) that infects the silkworm, B. mori, accounts for .50% of silk cocoon crop losses globally. We speculated that simultaneous targeting of several BmNPV essential genes in transgenic silkworm would elicit a stable defense against the virus. We introduced into the silkworm germline the vectors carrying short sequences of four essential BmNPV genes in tandem, either in sense or antisense or in inverted-repeat arrangement. The transgenic silkworms carrying the inverted repeat-containing transgene showed stable protection against high doses of baculovirus infection. Further, the antiviral trait was incorporated to a commercially productive silkworm strain highly susceptible to BmNPV. This led to combining the high-yielding cocoon and silk traits of the parental commercial strain and a very high level of refractoriness (.75% survival rate as compared to ,15% in nontransgenic lines) to baculovirus infection conferred by the transgene. We also observed impaired infectivity of the occlusion bodies derived from the transgenic lines as compared to the wild-type ones. Currently, large-scale exploitation of these transgenic lines is underway to bring about economic transformation of sericulture. R NA interference (RNAi) is a mechanism by which cells silence the expression of foreign genes. This process often provides an adaptive innate immunity against viruses where double-stranded RNAs encoded by the viruses during infection act as pathogen trigger after they are taken up by the cellular RNAi machinery (Wang et al. 2006). Alternatively, this natural defense mechanism is exploited as an antiviral therapy via the artificial inhibition of the expression of essential viral genes (Leonard and Schaffer 2006). Multiple protocols of delivery of dsRNA or of constructs encoding dsRNAs in the organism are currently under assay to combat infections of various viruses. The efficiency of the assays is still challenged by the delicate setting of the proper dosage of the RNAi, the relative longevity of the effect, the occurrence of RNAi driven toxicity, and the virus-intrinsic susceptibility. A few attempts have been made in animal and plant models where the antiviral trait was installed by transgenesis to confer stable protection to the transformed individuals and to their progeny. Successes have been reached in plants ( Bucher et al. 2006;Bonfim et al. 2007;Zhang 2010) but, to our knowledge, no case has yet been reported in animals showing a stable and robust protection against a virus after a RNAi-aided antiviral trait was introduced through germline transformation.The baculovirus, Bombyx mori nucleopolyhedrovirus (BmNPV), is a major pathogen that affects silkworm rearings and hampers silk cocoon production in Asia. In India alone .50% of silk cocoon crop losses are attributed to baculovirus infection (Khurad et al. 2006). Effective treatment against the virus has been elusive due to its sturdy nature and the lack of control strategies. Interestingly, the biology of the virus is reasonably...

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This study was designed to evaluate the effect of four remineralizing agents on surface topography of dentin.Materials and methods: 75 Teeth were divided according to the remineralizing agents into five treatment groups (Control C, CPP-ACP A, NovaMin V, n-HA N & NaF F) 15 teeth each. Time of pH cycling periods were divided to (one week (W1), two weeks (W2) and five weeks (W5)Results: Regarding all of pH cycle periods (W1, W2&W5); there was statistically significant difference between mean dentinal tubules diameter values of the control group on one hand and each of A, V, N and F groups on the other hand. However, there was no statistically significance difference between all those remineralizing agents. The N groups showed the lowest mean value of dentinal tubules diameter while the F groups showed the highest mean value of dentinal tubules diameter.Conclusions: Surface topography of dentin is positively affected by the application of remineralizing agents. Increasing the application rate (pH cycling periods) of the remineralizing agents significantly affect the surface topography of dentin.

Aim: This research evaluates the effect of different types of glass ionomer restorations on surface microhardness and remineralization of dentin.Materials and methods: Three of glass ionomer restorations (medi fil, equia fil and zirconomer) were used. A total number of 32 sound non-carious human premolar teeth extracted for orthodontic reasons were used in this study. Standardized two class V cavities, one on the buccal and other on lingual surface of each tooth were prepared. The cavity preparation was 3, 2, and 1.5 mm for width, height and depth respectively. The teeth were sectioned mesio-distally to get (64) then divided into three equal main groups (21 teeth each) according to the restorative materials, group (M): medi fil group (E): equia fil group and (Z): zirconomer group. Each group was further subdivided into three equal divisions (7 teeth each) according to the storage times; one day (S1), one month (S2) and three months (S3). The specimens were sectioned longitudinally along the middle of the restorations to produce two blocks . One part was mounted in epoxy resin for microhardness testing, and the other for energy dispersive x -ray analysis (EDX). Specimens were stored in artificial saliva for one day, one month and three months before testing. A microhardness tester was used to measure the Vickers hardness number.Results: It was found that the highest mean value of surface micro hardness and remineralization was recorded for medi fil group, while the lowest mean value was recorded for equia fil group. Pairwise Tukey's post-hoc test showed no-significant between one month and three-month storage. Conclusion:It can be concluded that all glass ionomer restorations show remineralization to tooth structures also zirconomer overpowered by conventional glass ionomer because its high fluoride release finally equia-fil show increase remineralization with time.

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