ABSTRACT Objective: To assess the effectiveness of platelet-rich fibrin (PRF) with decalcified freeze-dried bone allograft (DFDBA) compared to DFDBA alone in mandibular grade-II furcation defects. Material and Methods: A quasi-experimental study was conducted on nine patients with chronic periodontitis, each having two almost identical mandibular grade II furcation defects. Test sites (left mandibular first molars) were treated with open flap debridement (OFD), DFDBA, and PRF, whereas control sites (right mandibular first molars) received OFD and DFDBA alone. Clinical parameters (plaque index (PI), gingival index (GI), vertical clinical attachment level (VCAL) and horizontal clinical attachment level (HCAL) into the furcation defect) and radiographic measurements (mean alveolar bone defect) were done at baseline and after six months postoperatively. Results: The gain in relative horizontal clinical attachment level (RHCAL) in the test sites was 2.94±0.52 mm compared to 1.33±0.35 mm in control sites (p=0.01). Improvement in mean alveolar bone defect (MABD) (was 1.21±0.5 mm2 at test sites compared to 1.15±0.7 mm2 at control sites) probing pocket depth (PPD), recession, relative vertical attachment level (RVCAL), and percentage of bone fill was found in the test sites compared to control, which statistically insignificant. Conclusion: The test sites had better outcomes than control sites, which was significant for the parameter RHCAL. Therefore, combining the biological benefits of autologous PRF with DFDBA is an efficient and economical treatment modality for the management of mandibular grade II furcation defects.

Abstract Background: The oral cavities of snakes are replete with various types of bacterial flora. Culture-dependent studies suggest that some of the bacterial species are responsible for secondary bacterial infection associated with snakebite. A complete profile of the ophidian oral bacterial community has been unreported until now. Therefore, in the present study, we determined the complete bacterial compositions in the oral cavity of some snakes from India. Methods: Total DNA was isolated from oral swabs collected from three wild snake species (Indian Cobra, King Cobra and Indian Python). Next, the DNA was subjected to PCR amplification of microbial 16S rRNA gene using V3-region-specific primers. The amplicons were used for preparation of DNA libraries that were sequenced on an Illumina MiSeq platform. Results: The cluster-based taxonomy analysis revealed that Proteobacteria and Actinobacteria were the most predominant phyla present in the oral cavities of snakes. This result indicates that snakes show more similarities to birds than mammals as to their oral bacterial communities. Furthermore, our study reports all the unique and common bacterial species (total: 147) found among the oral microbes of snakes studied, while the majority of commonly abundant species were pathogens or opportunistic pathogens to humans. A wide difference in ophidian oral bacterial flora suggests variation by individual, species and geographical region. Conclusion: The present study would provide a foundation for further research on snakes to recognize the potential drugs/antibiotics for the different infectious diseases.

OBJECTIVES: The present study aimed to evaluate the dynamics of CD28 and CD57 expression in CD8+ T lymphocytes during cytomegalovirus viremia in bone marrow transplant recipients. METHODS: In a prospective study, blood samples were obtained once weekly once from 33 healthy volunteers and weekly from 33 patients. To evaluate the expression of CD57 and CD28 on CD8+ T lymphocytes, flow cytometry analysis was performed on blood samples for four months after bone marrow transplant, together with cytomegalovirus antigenemia assays. RESULTS: Compared to cytomegalovirus-seronegative healthy subjects, seropositive healthy subjects demonstrated a higher percentage of CD57+ and a lower percentage of CD28+ cells (p<0.05). A linear regression model demonstrated a continuous decrease in CD28+ expression and a continuous increase in CD57+ expression after bone marrow transplant. The occurrence of cytomegalovirus antigenemia was associated with a steep drop in the percentage of CD28+ cells (5.94%, p<0.01) and an increase in CD57+ lymphocytes (5.60%, p<0.01). This cytomegalovirus-dependent effect was for the most part concentrated in the allogeneic bone marrow transplant patients. The development of acute graft versus host disease, which occurred at an earlier time than antigenemia (day 26 vs. day 56 post- bone marrow transplant), also had an impact on the CD57+ subset, triggering an increase of 4.9% in CD57+ lymphocytes (p<0.05). CONCLUSION: We found continuous relative changes in the CD28+ and CD57+ subsets during the first 120 days post- bone marrow transplant, as part of immune system reconstitution and maturation. A clear correlation was observed between the expansion of the CD57+CD28-CD8+ T lymphocyte subpopulation and the occurrence of graft versus host disease and cytomegalovirus viremia.

The discussion will focus on the role of the ribosomal protein S6 kinase (S6K) signaling pathway in the regulation of cell growth and proliferation. Although 40S ribosomal protein S6 phosphorylation was first described 25 years ago (<A HREF="#20">Gressner and Wool, 1974</A>), it only recently has been implicated in the translational up-regulation of mRNAs coding for the components of protein synthetic apparatus (<A HREF="#15">Fumagalli and Thomas, 2000</A>). These mRNAs contain an oligopyrimidine tract at their 5' transcriptional start site, termed a 5'TOP, which has been shown to be essential for their regulation at the translational level (<A HREF="#32">Meyuhas et al., 1996</A>). In parallel, a great deal of information has accumulated concerning the identification of the signaling pathway and the regulatory phosphorylation sites involved in controlling S6K activation (<A HREF="#13">Dufner and Thomas, 1999</A>). Despite this knowledge we are only beginning to identify the direct upstream elements involved in growth factor-induced kinase activation (<A HREF="#9">Dennis et al., 2001</A>; <A HREF="#38">Pullen et al., 1998</A>). Use of the immunosuppressant rapamycin, a bacterial macrolide, in conjunction with dominant interfering and activated forms of S6K1 has helped to establish the role of this signaling cascade in the regulation of growth and proliferation (<A HREF="#11">Dennis and Thomas, 2002</A>). In addition, current studies employing the mouse as well as Drosophila melanogaster have provided new insights into physiological function of S6K in the animal (<A HREF="#33">Montagne et al., 1999</A>; <A HREF="#36">Pende et al., 2000</A>). Loss of dS6K function in Drosophila melanogaster demonstrated its paramount importance in development and growth control (<A HREF="#33">Montagne et al., 1999</A>), whereas deletion of the S6K1 gene in the mouse led to an animal of reduced size and the identification of the S6K1 homologue, S6K2 (<A HREF="#44">Shima et al., 1998</A>). Such mice are significantly smaller during fetal development (<A HREF="#44">Shima et al., 1998</A>) and hypoinsulinemic in the adult, conditions known to lead to type 2 diabetes (<A HREF="#36">Pende et al., 2000</A>).