Detection of Bacteroides forsythus and Porphyromonas gingivalis in infected root canals during periapical periodontitis by 16S rDNA

Periapical periodontitis is termed when inflammation of the periodontium is caused by irritants of endodontic origin. Bacterial strains in the root canals were not easy to be identified by the traditional agar culture. In this study a 16S rDNA-based polymerase chain reaction detection method was used to determine the occurrence of Bacteroides forsythus and Porphyromonas gingivalis in chronic periapical periodontitis among Chinese patients. 217 patients with chronic periapcial periodontitis were recruited and a total of 266 teeth were collected. The subjects had no systemic diseases, no antibiotics taken, no root canal treatment (RCT) performed on the infected teeth in the last 3 months. The DNA of bacteria in the root canal was extracted and amplified using universal 16S rDNA primers. The amplification was performed to detect B. forsythus and P. gingivalis using oligonucleotide primers designed from species-specific 16S rDNA signature sequences. B. forsythus and P. gingivalis were detected in 26 and 40% of the participants, respectively. 24 out of 217 infected root canals demonstrated the existence of both types of bacteria, the utility of a 16S rDNA-based PCR detection method showed high sensitivity and high specificity to directly detect B. forsythus, P. gingivalis or other pulpal microorganisms from samples of root canal infections. The results indicated that B. forsythus or P. gingivalis might be a member of the microbiota associated with chronic periapical periodontitis and there was a strong association between the studied species and periodontitis. © 2009 Academic Journals.published_or_final_versio

Polistes olivaceous decreases biotic surface colonization

The objective of this investigation was to evaluate the anti-bacterial efficacy of the honeycomb of Polistes olivaceous on oral biotic surface (biofilm) model by means of pH response, population of oral bacteria and enamel mineralization. Three copies of a three-organism-bacterial consortium was grown on hydroxyapatite (HA) surfaces in a continuous culture system and exposed to repeated solution pulses of sucrose solution every 12 h to construct a cariogenic biofilm on the HA discs in the flow cells. One flow cell was only pulsed with 500 μmol/ml of sucrose (S group). The second flow cell was pulsed with 500 μmol/ml sucrose and 2.5 mg/ml P. olivaceous extract (P group). The third flow cell was pulsed with 500 μmol/ml sucrose, 230 mg/L sodium fluoride and 0.2% chlorohexidine digluconate (C group). During the course of carbohydrate supplement, the pH of the S group dropped sharply compared with the others. The P group demonstrated pH recovery to baseline more easily than the S group (p < 0.05). The C group demonstrated very little pH drop. The P group displayed a lower level of colonization than the S group, which was reflected by a lower cariogenic bacterial count and a less compact biofilm especially after the third pulse. P. olivaceous suppresses bacteria growth and accelerates pH recovery. P. olivaceous may have stabilizing effect against cariogenic shift on the oral biofilm, preventing tooth decay. © 2009 Academic Journals.published_or_final_versio

HIV-Infected Former Plasma Donors in Rural Central China: From Infection to Survival Outcomes, 1985–2008

BACKGROUND: The HIV epidemic among former plasma donors (FPDs) in rural Central China in the early-mid 1990s is likely the largest known HIV-infected cohort in the world related to commercial plasma donation but has never been fully described. The objectives of this study are to estimate the timing and geographic spread of HIV infection in this cohort and to demonstrate the impact of antiretroviral therapy on survival outcomes. METHODOLOGY/PRINCIPAL FINDINGS: HIV-infected FPDs were identified using the national HIV epidemiology and treatment databases. Locations of subjects were mapped. Dates of infection and survival were estimated using the midpoint date between initial-final plasma donation dates from 1985-2008 among those with plasma donation windows ≤2 years. Among 37,084 FPDs in the two databases, 36,110 were included. 95% were located in focal areas of Henan Province and adjacent areas of surrounding provinces. Midpoint year between initial-final plasma donation dates was 1994 among FPDs with known donation dates. Median survival from infection to AIDS was 11.8 years and, among those not treated, 1.6 years from AIDS to death. Among those on treatment, 71% were still alive after five years. Using Cox proportional hazard modeling, untreated AIDS patients were 4.9 times (95% confidence interval 4.6-5.2) more likely to die than those on treatment. CONCLUSIONS/SIGNIFICANCE: The epidemic of HIV-infected FPD in China was not widespread throughout China but rather was centered in Henan Province and the adjacent areas of surrounding provinces. Even in these areas, infections were concentrated in focal locations. Overall, HIV infections in this cohort peaked in 1994, with median survival of 13.4 years from infection to death among those not treated. Among AIDS patients on treatment, 71% were still alive after five years

Activation of Latent HIV Using Drug-Loaded Nanoparticles

Antiretroviral therapy is currently only capable of controlling HIV replication rather than completely eradicating virus from patients. This is due in part to the establishment of a latent virus reservoir in resting CD4+ T cells, which persists even in the presence of HAART. It is thought that forced activation of latently infected cells could induce virus production, allowing targeting of the cell by the immune response. A variety of molecules are able to stimulate HIV from latency. However no tested purging strategy has proven capable of eliminating the infection completely or preventing viral rebound if therapy is stopped. Hence novel latency activation approaches are required. Nanoparticles can offer several advantages over more traditional drug delivery methods, including improved drug solubility, stability, and the ability to simultaneously target multiple different molecules to particular cell or tissue types. Here we describe the development of a novel lipid nanoparticle with the protein kinase C activator bryostatin-2 incorporated (LNP-Bry). These particles can target and activate primary human CD4+ T-cells and stimulate latent virus production from human T-cell lines in vitro and from latently infected cells in a humanized mouse model ex vivo. This activation was synergistically enhanced by the HDAC inhibitor sodium butyrate. Furthermore, LNP-Bry can also be loaded with the protease inhibitor nelfinavir (LNP-Bry-Nel), producing a particle capable of both activating latent virus and inhibiting viral spread. Taken together these data demonstrate the ability of nanotechnological approaches to provide improved methods for activating latent HIV and provide key proof-of-principle experiments showing how novel delivery systems may enhance future HIV therapy