Evaluation of antimicrobial efficacy of Triphala (an Indian Ayurvedic herbal formulation) and 0.2% chlorhexidine against Streptococcus mutans biofilm formed on tooth substrate: An in vitro study.

Background: Streptococcus mutans is one of the most important cariogenic species of the human oral microbial flora. Biofilm style of microbial growth thought to resist the actions of antimicrobials. Aim: The purpose of this study was to evaluate the antimicrobial efficacy of Triphala, and 0.2% chlorhexidine against S. mutans biofilm formed on tooth substrate. Settings and Design: Randomized control trial. Methods: Extracted human mandibular premolars sectioned below the cemento‑enamel junction were placed in the tissue culture wells exposing the crown surface to S. mutans to form a biofilm. At the end of 3rd and 7th day, all groups were treated for 10 min with the test solutions and control and were analyzed qualitatively and quantitatively. Statistical Analysis Used: One‑way ANOVA. Results: Qualitative assay with 3 days biofilm showed complete inhibition of bacterial growth with Triphala, but 0.2% chlorhexidine and saline showed the presence of bacterial growth. In quantitative analysis, 0.2% chlorhexidine and Saline treated tooth samples have shown 1052 × 104 ± 15.1 × 104 CFU/ml, 141.3 × 109 ± 2.1×109 CFU/ml, respectively. Qualitative assay with 7 days biofilm on crown portion showed dense growth when treated with 0.2% chlorhexidine and saline, whereas Triphala has shown minimal growth. In Quantitative analysis, Triphala showed statistically significant result when compared with 0.2% chlorhexidine and saline. Conclusion: Triphala showed statistically significant antibacterial activity against S. mutans biofilm formed on tooth substrate. The incorporation of Triphala in mouth rinse could prove to be effective in reducing S. mutans count in the oral cavity.

No evidence for successful interspecific cross-mating of transgenic Aedes aegypti (L.) and wild type Aedes albopictus Skuse

The natural and artificial mating of laboratory bred Aedes albopictus and transgenic Aedes aegypti RIDL-513A-Malaysian strain was conducted. The experiment consisted of crossmating of homologous Ae. aegypti RIDL female symbol X Ae. aegypti RIDL male symbol and reciprocal Ae. aegypti RIDL female symbol X Ae. albopictus WT male symbol. The other set comprised homologous Ae. albopictus WT female symbol X Ae. albopictus WT male symbol and reciprocal Ae. albopictus WT female symbol X Ae. aegypti RIDL male symbol. This study demonstrated that reproductive barriers exist between these two species. Cross insemination occurred between A. albopictus male and Ae. aegypti female and their reciprocals. There was 26.67% and 33.33% insemination rate in Ae. aegypti RIDL female cross-mating with A. albopictus WT male and Ae. albopictus female cross-mating with Ae. aegypti RIDL male, respectively. There was 0% hatchability in both directions of the reciprocals. There was also no embryonation of these eggs which were bleached. Although none of the female Ae. albopictus WT was inseminated in the cross-mating with Ae. albopictus WT female symbol X Ae. aegypti RIDL male symbol, a total of 573 eggs were obtained. The homologous mating was very productive resulting in both high insemination rate and hatchability rates. Generally there was a significantly higher insemination rate with artificial mating insemination of homologous than with artificial mating of reciprocal crosses. Interspecific mating between Ae. aegypti RIDL and Ae. albopictus wild type was not productive and no hybrid was obtained, indicating absence of horizontal transfer of introduced RIDL gene in Ae. aegypti to Ae. albopictus.

ATP7B mutations in families in a predominantly Southern Indian cohort of Wilson's disease patients.

OBJECTIVE: To analyze ATP7B mutations in Wilson's disease (WD) patients from the Indian subcontinent and to correlate these with WD phenotype. METHODS: We studied 27 WD patients from 25 unrelated families. Twenty-two families were from three southern Indian states - Tamil Nadu andhra Pradesh and Kerala. We applied conformation- sensitive gel electrophoresis (CSGE) to screen for the mutations in patients and their families. PCR products exhibiting aberrant patterns in CSGE were subjected to direct DNA sequencing. As siblings affected by WD within a family share identical ATP7B genotype, we compared WD phenotype among affected siblings within families. RESULTS: ATP7B mutations were detected in 22 of the 25 probands -13 were homozygotes and 9 were compound heterozygotes. Eleven novel mutations were detected. Only two common mutations were found: G3182A in 4 (16%) and C813A in 3 (12%) probands. 'Hot spots' for ATP7B mutations were exons 18 and 13. Lack of common dominant mutations prevented correlation of individual ATP7B mutations with WD phenotype. Symptomatic WD in a live sibling was not found in any family. In 8 families, a sibling died of presumed WD - in 6 of these, WD phenotype was identical to that in the proband. CONCLUSIONS: We describe the spectrum of ATP7B mutations including 11 novel mutations in Indian WD patients and document lack of a single dominant mutation. Identical WD phenotype among siblings in only 6 of 8 families with >1 child affected by WD suggests that factors other than ATP7B mutations influence WD phenotype.

Community prevalence of antibodies to human immunodeficiency virus in rural and urban Vellore, Tamil Nadu.

BACKGROUND: Human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) are becoming increasingly common in India. Currently, antenatal prevalence is a surrogate marker for HIV prevalence in the community. The association between antenatal and community prevalence of HIV needs to be validated so that estimates can be verified or adjusted appropriately. METHODS: A probability proportional to size cluster survey was conducted in the Kaniyambadi block of Vellore district and in the urban wards of Vellore town to estimate the prevalence of antibodies to rubella from August 1999 to February 2000. All personal identifier data from the serum samples were removed to yield a collection for which only the age and sex were known. Estimation of antibodies to HIV in sera from individuals between 15 and 40 years of age, was carried out by one screening ELISA and the reactive sera were further subjected to a supplementary test. RESULTS: We tested 1512 serum samples from subjects residing in rural areas and 1358 samples from those residing in urban areas. The seropositivity among rural samples was 0.66% and among urban samples 1.4%. The prevalence was almost equal among men and women and the youngest infected individual was 15 years old. CONCLUSION: The prevalence of HIV during the period of study was similar to the national surveillance data for Tamil Nadu based on antenatal women. HIV prevalence differs in urban and rural Tamil Nadu, with urban areas having a higher burden of the disease.

Alterations in tumour suppressor gene p53 in human gliomas from Indian patients.

Alterations in tumour suppressor p53 gene are the most common defects seen in a variety of human cancers. In order to study the significance of the p53 gene in the genesis and development of human glioma from Indian patients, we checked 44 untreated primary gliomas for mutations in exons 5-9 of the p53 gene by PCR-SSCP and DNA sequencing. Sequencing analysis revealed six missense mutations. The incidence of p53 mutations was 13.6% (6 of 44). All the six mutations were found to be located in the central core domain of p53, which carries the sequence-specific DNA-binding domain. These results suggest a rather low incidence but a definite involvement of p53 mutations in the gliomas of Indian patients.