[Dynamic and quantitative analysis of cariogenic bacteria and its proportion in the dental plaque of different caries-susceptible children].

Purpose: To investigate the ratio and change of bacteria in dental plaque in different caries-susceptible children.

Methods: Dental plaques were obtained from 60 children of 3-5 years old. Four targeted cariogenic bacteria were quantitatively detected by real-time PCR and the mean dmft score was calculated.

[The influence of starvation on Candida albicans biofilm and persisters formation].

Purpose: To investigate the influence of starvation on Candida albicans (C. albicans) biofilm and persisters formation.

Methods: The growth curve was made by CFU counts methods in different culture times to find the exponential and stationary phases.

[Dynamic monitoring and analysis of the persisters emerging in Candida albicans biofilm].

Purpose: To investigate the mechanism and approach related to persisters emerging in Candida albicans biofilm by studying its dynamic characteristics.

Methods: The Candida albicans biofilms model in vitro were formed by individual yeast cells and hyphal compartments respectively. The numbers of progenitive fungal cells and persisters at different stages were counted and analyzed with SPSS11.

Fluconazole susceptibility and genotypic heterogeneity of oral Candida albicans colonies from the patients with cancer receiving chemotherapy in China.

Aim: To identify heterogeneity of Candida albicans (C. albicans) isolated from the population with cancer in China by using identification medium, subculture molecular typing, and antifungal susceptibility test.

Methodology: Oral cheek mucosal specimens from 52 cancer patients receiving chemotherapy were cultured on CHROMagar Candida plates for Candida identification.

[In vitro study of the secondary mesiobuccal canal of the maxillary second molar].

Objective: To get some anatomical knowledge about the second mesiobuccal canal (MB2) of the maxillary second molar of Shandong region by studying the teeth in vitro. The anatomical knowledge may help us to improve the successful rate of root canal therapy of the maxillary molar.

Methods: 118 maxillary second molars were collected from the different region in Shandong province.

[Distribution and genotypic subgroup of oral Saccharomyces albicans isolated from cancer patients receiving chemotherapy].

Objective: The objective of this study is to study the distribution and molecular characteristics of the oral Saccharomyces albicans (S. albicans) in the cancer patients receiving chemotherapy.

Methods: 390 cancer patients receiving chemotherapy were sampled by oral mucosal swab.

[Roles of drug efflux pump genes in the mechanism of Saccharomyces albicans biofilm drug tolerance].

Objective: Saccharomyces albicons is the main opportunistic pathogen which is also the common member of oral microflora, and the biofilms they formed have spontaneous drug tolerance compared with planktonic ones. Saccharomyces biofilm population can produce subpopulation of cells which can tolerant high concentration of antifungal drugs. They are called persisters.

[Study on oral Candida albicans apoptosis in vitro].

Purpose: Candida albicans is one of the main opportunistic pathogen for human , the aim of this study is to investigate the phenomena of apoptosis in oral Candida albicans induced by acetic acid.

Methods: The Candida albicans of clinical strains were induced to apoptosis by using a weak acid acetic acid.The apoptosis was detected by flow cytometry and TEM.

[Dynamic study on saccharomyces albicans drug efflux pumps gene expression during the biofilm formation].

Objective: To observe the drug resistance and drug efflux pumps gene mRNA of Saccharomyces albicans, including CDR1 gene and MDR1 gene, at different stage of biofilm formation in chemostat, furthermore to analysis the relationship between the drug efflux pump gene expression and the biofilm related drug resistance.

Methods: To form the mature biofilm in vitro in chemostat, then collect the biofilm strains at different development stages (2, 12, 24, 48 h) to semi-quantified mRNA amount of CDR1 gene and MDR1 gene by one step RT-PCR method. Using XTT reduction method to test the dynamic change of Saccharomyces albicans drug resistance in biofilm.

[Genetic diversity of F-ATPase subunits gene uncEBF amplified from Streptococcus mutans clinical isolates].

Objective: The purpose of this research was to study the genetic diversity of F-ATPase subunit gene uncEBF derived from Streptococcus mutans (S. mutans) clinical isolates, furthermore to investigate the relationship between the genetic diversity of F-ATPase and S. mutans aciduric ability.

[Genetic diversity and mRNA expression of F-ATPase subunit uncG gene of streptococcus mutans clinical isolates].

Objective: To study the genetic diversity and the gene expression of membrane-bound proton-translocating ATPase (F-ATPase) subunit gene uncG derived from Streptococcus mutans (S. mutans) clinical isolates.

Methods: 38 S.

[A study of genetic diversity in lactate dehydrogenase of Streptococcus mutans from clinical isolates].

Objectives: Lactate dehydrogenase (LDH) is shown to be an important virulence factor resulting in acid production of Streptococcus mutans (S. mutans), on which the cariogenic potential of S. mutans depends.

[Genetic diversity of F-ATPase subunits gene uncA amplified from Streptococcus mutans clinical isolates].

Objective: To study the genetic diversity of F-ATPase alpha subunit gene uncA derived from Streptococcus mutans (S. mutans) clinical isolates and to investigate the relationship between the genetic diversity of acidurance factor and S. mutans aciduric ability, also and the cariogenicity.

[The distribution of Candida spp. in the oral cavities of normal children].

Objective: To study the distribution of Candida spp. mainly Candida albicans in the oral cavities of health children.

Methods: Four groups children of different ages, A1: newborn babies, A2: 3.