Biomedical subjects

Xiaorong Xiao

Publications and source records attributed to Xiaorong Xiao.

10 recordsLinked to original sources

PubMed2003

[Effect of para-aminobenzonic acid on cell-surface hydrophobicity of Actinomyces viscosus].

OBJECTIVE: To study the effect of Para-aminobenzonic acid (PABA) on cell-surface hydrophobicity of Actinomyces viscosus. METHODS: Microbial adhesion to hydrocarbons (MATH) was used to measure the cell-surface hydrophobicity of Actinomyces viscosus which grew in modified Carlsson medium with different dilution of PABA. RESULTS: Following the increase of concentration of PABA, the value of cell-surface hydrophobicity of Actinomyces viscosus decreased, which were 0.38900 +/- 0.00026, 0.25462 +/- 0.00168, 0.16360 +/- 0.00026 respectively(P < 0.05). CONCLUSION: PABA could inhibit the adherence of Actinomyces viscosus by way of changing its cell-surface hydrophobicity.

4-Aminobenzoic Acid↗

PubMed2003

[Effect of Radix scutellariae on the growth and form of Porphyromanus endodontics in vitro].

OBJECTIVE: To provide scientific evidence for underpinning the use of Radix Scutellariae in the treatment of pulp and periapical diseases. METHODS: Using minute amount serial dilution test, this study assessed the minimal inhibitory concentration of Radix Scutellariae extreact against Porphyromanus Endodontics. The forms of Porphyromanus endodontics treated with Radix Scutellariae extract at different concentrations were observed by use of SEM. RESULTS: The MIC of Radix Scutellariae extract was determined to be 1 mg/ml. Radix Scutellariae changed the forms of Porphyromanus endodontics, making them become bigger, longer and crumbled. CONCLUSION: Radix Scutellariae could inhibit the growth of Porphyromanus Endodontics.

Dental Pulp↗

PubMed2003

[Scanning electron microscope observation of morphological influence P-aminobenzoic acid (PABA) on Porphyromonas gingivalis].

OBJECTIVE: In order to investigate the effect of PABA produced by Streptococcus sanguis on microecological balance of subgingival plaque, different concentrations of PABA were applied to see if it can influence the form and adherence of P. gingivalis. METHODS: After adding different concentrations of PABA into 1/2 concentration of BHI media, an anaerobic technique was used to culture P. gingivalis. P. gingivalis grew in the medium was observed by a scanning electron microscope. RESULTS: Excessively high or low PABA concentration could influence the form and adherence of P. gingivalis. CONCLUSION: PABA produced by Streptococcus sanguis can affect the form and adherence of P. gingivalis. It indicates that Streptococcus sanguis plays regulative effect on the microecological balance of subgingival plaques.

4-Aminobenzoic Acid↗

PubMed2003

[A comparative study utilizing different methods for establishing an experimental periodontitis model in rats].

OBJECTIVE: To evaluate the experimental periodontitis in rats induced by ligature plus high sugar water with and without infection of periodontopathic bacteria. METHODS: Forty SD rats (5 weeks of age) were randomly divided into a control group (N) and three experimental groups (P1, P2 and P3). All experimental groups were given silk ligatures around the cervix of the second maxillary molars and were provided with drinking water containing 10% glucose. Group P2 was inoculated with P. gingivalis, three times; group P3 was inoculated with P. gingivalis and F. nucleatum, three times. At weeks 0, 2 and 4, microbiological and histological examinations were made; alveolar bone loss was stereoscopically measured as the distance from the cement-enamel junction to the alveolar crest. RESULTS: Microbiological examination indicated that the bacteria inoculated in groups P2 and P3 were successfully colonized and both of P. gingivalis and F. nucleatum were predominant among the bacterial colonies of the examined sites. At week 2, histological examination showed gingival erosion and alveolar bone loss in all experimental groups and periodontal pockets in groups P2 and P3. The most serious lesions were observed in group P3. At week 4, the periodontal destruction in all experimental groups became more severe. CONCLUSION: Ligature, high sugar water combined with mixed infection of periodontopathic bacteria can successfully induce experimental periodontitis in rats.

Animals↗

PubMed2002

The effect of para-aminobenzoic acid on growth and metabolism of Porphyromonas gingivalis.

OBJECTIVE: To study the effect of para-aminobenzoic acid (PABA) on the growth and metabolism of Porphyromonas gingivalis (P.g). METHODS: After adding different concentrations of PABA into the medium, anaerobic technique was applied to culture P.g. The products' A value and action of TLP was assayed, and P.g grew in the medium was observed by a scanning electron microscope. RESULTS: PABA promoted the growth of P.g and action of TLP, which would reach the highest level when PABA was 1 mg/L, and would decrease with the increasing of concentration of PABA. When the concentration arrived at 100 mg/L, PABA had no effect on them. In the mean time, PABA had effect on the form and adherence of P.g. When the concentration was 1 mg/L and 100 mg/L, this effect was strong, but as the concentration was 10 mg/L, the effect disappeared. CONCLUSIONS: PABA influences the growth and metabolism of P.g, which indicate that Streptococcus sanguis has regulative effect on the microecology of subgingival plaque.

4-Aminobenzoic Acid↗

PubMed2002

[Effect of para-aminobenzoic acid on the growth of Actinomyces viscosus].

OBJECTIVE: To examine the effects of para-aminobenzoic acid (PABA) on the growth of Actinomyces viscosus. METHODS: Different concentrations of PABA (10(-10)-10(-3) g/L) were each transferred to modified Carlsson medium. Actinomyces viscosus ATCC19246 grew in them. And the cultures were incubated at 37 degrees C anaerobically in the atmosphere of 80%N2, 10%H2, 10%CO2 for 48 h. Actinomyces viscosus OD values (lambda = 540 nm) were obtained with UV-1601. Colony forming unit (CFU) was established by growth of Actinomyces viscosus in culture when different concentrations of PABA (10(-10)-10(-3) g/L) were present. RESULTS: Different concentrations of PABA (10(-10)-10(-4) g/L) had different stimulating effects on the growth of Actinomyces viscosus (P < 0.05). But this kind of stimulating effect declined when PABA concentration was 10(-5) g/L, and as PABA (10(-3) g/L) was present, this kind of effect was missing. CONCLUSION: The phenomena indicated that PABA has stimulating effect on the growth of Actinomyces viscosus, particularly when PABA is at the concentration of 10(-6) g/L.

Actinomyces viscosus↗

PubMed2002

[The influence of two implant materials on the growth of three subgingival predominant bacteria].

OBJECTIVE: Commercially pure titanium and titanium alloy as dental implants have show impressive clinical results. Despite the high success rates, some implants do fail. Compared to those studies on osseointegration of implants, the information pertaining to their failure is little. Further studies on the relationship between implant material and micro-organism are needed. The purpose of this investigation is to study the effect of two commonly used implant materials Titanium (TA2) and Ti-6AI-4V alloy (TC4) on the growth behaviour of three subgingival predominant bacteria Streptococcus sanguis (S. s), Porphyromanus gingivalis (P. g), Fusobacterium nucleatum (F. n) and their mixture. METHODS: Under anaerobic condition, bacterial suspensions of S.s, P.g, F.n and their mixture were incubated together with the two implant materials respectively, setting the same bacterial suspensions as controls. After 2, 7 and 14 days, the bacterial growth amount was assayed by means of clone forming unit (CFU) method. The pH value of the bacterial suspension was determined by pH-Meter. RESULTS: The results showed that there was no difference in amount of bacterial growth or pH value between TA2 group and TC4 group (P > 0.05). There was also no statistically significant change as to the proportion of individual bacteria in bacterial mixture or the pH value of culture suspension. CONCLUSION: Under the condition of this investigation, the two studies implant materials have no examined influences on the growth of the subgingival bacteria and the pH value of their culture environment.

Alloys↗

PubMed2002

[The effects of fluoride-containing trace element agents on the growth of mutants of S. mutans].

OBJECTIVE: To compare the influence of 6 trace element agents containing fluoride versus 6 trace element agents not containing fluoride on the growth of mutants of S. mutans and detect the interaction between fluoride and trace elements. METHODS: Six trace element agents containing fluoride [SnF2, ZnF2, SrF2, LaF2, (NH3)2MoF8, NaF] and 6 trace element agents not containing fluoride [SnCl2, SrCl2, LaCl2, ZnAc2, (NH3)2MoO4, NaCl] were selected. The continuous anaerobic cultivating technique and the absorbency of bacteria liquid and the count of bacteria were used to assess the effects of different agents on the growth of S. mutans. RESULTS: NaF, SnF2, SnCl2, ZnF2, ZnAc2, (NH3)2MoF8 and (NH3)2MoO4 were found to have strong inhibition effects on the growth of mutant of S. mutans(P < 0.01). SnF2 had more stronger inhibition effects than SnCl2; ZnF2 had more stronger inhibition effects than ZnAc2, no significant differences were seen between (NH3)2MoF8 and (NH3)2MoO4. SnF2 and ZnF2 had most potent inhibition effects(P < 0.01). No significant differences were observed between SrF2, SrCl2, LaCl2, LaF2, NaCl and the control groups(P > 0.05). CONCLUSION: The agents containing fluoride and trace elements, such as stannum and zinc had the effects of prohibiting the growth of mutant of S. mutans, As far as caries prevention is concerned, the agents containing both fluoride and trace elements are more effective than mono-fluoride, the potential mechanism may be the synergistic action between fluoride and trace elements.

Cariostatic Agents↗

PubMed2002

[Quantitative changes of microflora on stress-bearing areas relating to bases of removable partial dentures].

OBJECTIVE: This study was designed to find out the changes in microflora on the stress-bearing areas after insertion of removable partial dentures, and in turn to explore the difference between such changes caused by metal bases and acrylic resin bases respectively. METHODS: Sixteen patients who were ready to accept removable partial dentures were selected and divided into two groups. Eight patients used metal bases while the other eight patients used acrylic resin bases. Then at the following three points: before dentures were inserted, one month after wearing and three months after wearing, the total cultivable flora were counted and the proportions of bacteria detected on the stress-bearing areas were calculated. RESULTS: No matter what type of bases was selected, the wearing of removable partial denture enhanced the accumulation of microflora on stress-bearing areas. The percentages of Candida albicans and Lactobacilli detected on stress-bearing areas also increased significantly (P < 0.05). When such changes were compared, the authors found that the increment of Candida albicans caused by acrylic resin bases was higher than that caused by metal bases (P < 0.05). CONCLUSION: The wearing of removable partial dentures forms new retention areas between the bases and the stress-bearing areas, as a result enhances the deposit of microbe and facilitate the growth of Candida albicans and Lactobacilli. Compared with increment of Candida albicans caused by metal bases, the increment relating to acrylic resin bases is more evident.

Aged↗

PubMed2002

[Oral microflora of 42 patients with oral squamous cell carcinoma].

OBJECTIVE: The purpose of this study was to evaluate the effects of squamous cell carcinoma on oral bacteria. METHODS: This study investigated the microbial contents of the plaque on the surfaces of oral squamous cell carcinomas. Samples were obtained from the central surface of lesions, contiguous healthy mucosa and saliva of 42 patients with oral squamous carcinoma before and after operation. RESULTS: The median of bacterial colony forming units per milliliter (CFUs/ml) of saliva before operation was 8.10 x 10(8) CFUs/ml. The median of CFUs per square centimeter of the tumor surface was 5.21 x 10(5) CFUs/cm2 which was significantly higher than that of the healthy (the control) mucosa (1.77 x 10(4) CFUs/cm2, P = 0.0001). The CFUs per square centimeter of mucosa surface at the operative zone was 4.34 x 10(5) CFUs/cm2 which was also significantly higher than that of the healthy (control) mucosa(7.24 x 10(4) CFUs/cm2, P = 0.0001). CONCLUSION: Oral carcinoma can break the balance of oral microflora, which may be one of the reasons leading to the high susceptivity of these compromised patients to systemic infection.

Adult↗