Factors affecting asymmetrical lower extremity loading after unilateral total knee arthroplasty / 医用生物力学

Total knee arthroplasty (TKA) is the most common surgery for treating late-stage knee osteoarthritis. Previous studies have shown that after unilateral TKA, the load-carrying on lower limbs is asymmetrical and the contralateral knee have to bear even greater loads. Therefore, the osteoarthritis side is susceptible to become even worse and under the risk of subsequent replacement. In this review, factors affecting asymmetrical loading on lower limbs, including changes in alignment, pain, muscle weakness, loss of proprioception, and psychological factors are reviewed. The overall effects of these affecting factors on human body, compensation of asymmetrical loading on the body segments and clinical interventions are also discussed. Specific clinical interventions can be introduced to reduce the risk of osteoarthritis or replacement of contralateral knee by analyzing the above factors affecting asymmetrical loading on lower limbs after unilateral TKA.

The latest progress in studies of human oral microbiome / 华西口腔医学杂志

With the successful implementation of Human Genome Project, more and more scientists started to pay attention on the second genome of human body: Microbiome. This paper will briefly introduce the latest developments of the Human Microbiome Project, the human oral microbiome research, and new technologies of microbial gene research.

Preliminary study on the discrimination of putative periodontal pathogens with a metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of identifying oral pathogenic bacteria by comparing the metabolic profiling of putative periodontal pathogens and try to find a convenient and rapid way to discriminate oral microorganisms.</p><p><b>METHODS</b>Suspensions of Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum with same density were prepared and cultured respectively at liquid BHI medium. Then the growth quantity was measured periodically through turbidimetry and the growth curves of the inoculated bacteria were completed. The culture solutions of stable growth phase were sampled and characterized by 1H-nuclear magnetic resonance 1H-NMR). The data of 1H-NMR spectroscope results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of three groups differentially centralized to three clusters. Therefore, the NMR-based metabonomics profiles could discriminate the three different kinds of bacteria.</p><p><b>CONCLUSION</b>The metabonomics is a potential classable method to identify the oral pathogenic bacteria.</p>

Initial study on the discrimination of oral common Actinomycetes with metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The method of metabonomics based on 1H-nuclear magnetic resonance (1H-NMR) was preliminarily applied to discriminate the oral common Actinomycetes, Actinomyces naeslundii ATCC12104 and Actinomyces israelii ATCC12102.</p><p><b>METHODS</b>Solutions of Actinomyces naeslundii and Actinomyces israelii with same density were made and cultured respectively at BHI liquid culture medium. The concentration of bacteria was determined periodically, and then the growth curves were drawn. The culture solutions in stationary phase of the two bacteria were used to test with the 1H-NMR spectroscopy respectively. The data of 1H-NMR spectroscopy results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of two groups data stayed differentially together by two clusters. Therefore, the NMR-based metabolomics profiles can discriminate the two different kinds of bacteria.</p><p><b>CONCLUSION</b>The analysis technology of metabonomics is expected to be applied to rapid identification of actinomycetes.</p>

Discrimination of common oral streptococcus with metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of identifying oral streptococcus by comparing their metabolic profiling, and to find a convenient and rapid way to discriminate oral microorganisms.</p><p><b>METHODS</b>The pure cultivation of Streptococcus sanguis ATCC 10556 and Streptococcus sobrinus 6715 (reference strain) from solid culture were respectively inoculated in TPY liquid medium. Then the growth quantity was measured periodically by turbidimetry and the growth curves of the inoculated bacteria were completed. The culture solutions in the stationary phase of the two bacteria were centrifuged, and then tested with the 1H-nuclear magnetic resonance (1H-NMR) spectrometer respectively. The gained free induction decay (FID) data were all inputted into MestReC Soft and finally transformed into metabolic profiling. The metabolic profiles were integrated segmentingly and the results were inputted into SIMCA-P Soft for principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA results showed the obvious clustering phenomena and the points of two group data differentially centralized in two clusters. Therefore, the NMR-based metabonomics profiles can discriminate the two different kinds of bacteria.</p><p><b>CONCLUSION</b>The metabonomics can be expected to be a kind of promising useful method in quick discrimination of oral streptococcus.</p>

Initial study on the discrimination of oral microorganisms with a metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish the spectra of metabolites that coued be employed in identification of oral pathogenic bacteria, and try to find a convenient and rapid way to discriminate oral microorganisms.</p><p><b>METHODS</b>Suspensions of Streptococcus mutans ATCC 25175, Streptococcus sanguis ATCC 10556 and Lactobacillus acidophilus ATCC 4356 with same density were preparecd and cultured respectively at improved TPY liquid culture medium. The growth quantity were measured periodically by a turbidimeter. And the growth curves of the inoculated bacteria were completed. The culture solutions in stationary phase of the three bacteria were tested with 1H-nuclear magnetic resonance (1H-NMR) spectroscopy respectively. The data of 1H-NMR spectroscopy results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of three group differentially centralized to three clusters. Therefore, the NMR-based metabonomics profiles could discriminate the three different kinds of bacteria.</p><p><b>CONCLUSION</b>The metabonomics is a promising new technology for developing to a rapid discrimination method of oral pathogenic bacteria.</p>

Cloning of ureI gene from Helicobacter pylori and its expression in E. coli / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone the urea membrane channel gene (ureI) from Helicobacter pylori (Hp) for its expression in E. coli, and evaluate the expression conditions and immunological features of the fusion protein.</p><p><b>METHODS</b>ureI gene cloned by PCR from Hp was inserted into the plasmid pET32a (+) to construct the recombinant plasmid pET32a/ureI, followed by identification by BglII and HindIII digestion and sequencing. E. coli BL-21+(DE3) was transformed with pET32a/ureI to obtain the engineered bacterium BL21+/UreI, which was cultured at different temperatures and induced with 1.0 mmol/L IPTG for expression of the recombinant protein. The expressed proteins were identified by SDS-PAGE and analyzed by Pro-gel analyzer 4.0. Western blotting was performed to evaluate the immunogenicity of the expressed protein.</p><p><b>RESULTS</b>The cloned gene fragment was about 650 bp in length, and BglII and HindIII digestion of pET32a/ureI yielded a 650-bp band. Sequence analysis revealed that the cloned ureI gene contained 646 bp without reading frame alterations. Comparison against GenBank indicated a homology of 100% of the cloned gene with ureI gene of the corresponding Hp strains, and also one no less than 98.5% with ureI gene from other strains. The engineered E. coli BL21+/UreI could express recombinant UreI (rUreI) with His tag, and the target protein accounted for 20.2% of the total bacterial proteins after 1.0 mmol/L IPTG induction of the bacterium at 37 degrees C for 14 h. SDS-PAGE and Western blotting showed that the recombinant UreI protein was produced mainly in the inclusion bodies and fused with his-tag (rUreI/his), which could react with human anti-Hp and mAb to his tag but not with mAb to Hp UreB.</p><p><b>CONCLUSIONS</b>We have successfully cloned ureI gene and constructed the prokaryotic expression plasmid for efficient rUreI expression, and the fusion protein rUreI/his expressed in the inclusion bodies can react specifically with both Hp antibody and his-tag antibody.</p>

Initial study on discrimination of oral microorganisms with the metabonomics technique / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of employing metabonomics method in identification of oral pathogenic bacteria.</p><p><b>METHODS</b>The Streptococcus mutans ATCC25175 and Actinomyces viscosus ATCC15987 were respectively inoculated in same certain culture medium. The growth curves of the inoculated bacteria were drown by turbidimetry. The culture solutions in four different growth phases of the both bacteria were used to test with the 1H-Nuclear magnetic resonance (1H-NMR) spectroscopy respectively. The data of 1H-NMR spectroscopy results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of two group data stayed differentially together by two clusters. Therefore, the NMR-based metabonomics profiles can discriminate the two different kind of bacteria.</p><p><b>CONCLUSION</b>The metabonomics can be expected to be a kind of promising useful method in quick discrimination of oral pathogenic bacteria.</p>

Dynamic release of tinidazole from the degradable PLLA-tinidazole blend gel / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To determine the dynamic release of tinidazole from the degradable poly-lactic acid (PLLA)-tinidazole blend gel (a periodontal local drug delivery) by high-performance liquid chromatography (HPLC) in vitro and to observe the polylactic acid (as a vector of tinidazole) how to affect the release of tinidazole.</p><p><b>METHODS</b>HPLC analysis was conducted. The operating conditions were C18-ODS-A column, water-methanol-acetic acid as mobile phase at a flow rate of 1.5 ml/min and a detection wavelength at 310 nm and a column temperature at 30 degrees C.</p><p><b>RESULTS</b>The retention time of tinidazole was about 12 min. There was good linear relationship between the concentrations of tinidazole in blend gel and their peak areas in the ranges of 5 - 500 mg/L. The regression reaction was y = 0.836 + 8.452 2 x 10(-5) x (r = 0.998 6). RSD was 0.2%. Polylactic acid had no influence on the determination of tinidazole. The daily average release of tinidazole was 5.60%. The cumulative release of tinidazole was about 78.40% in 14 days.</p><p><b>CONCLUSION</b>The in vitro drug release analysis is an useful method in evaluating the performance of local drug delivery system. HPLC analysis is a simple and accurate method with good reproducibility.</p>

Evaluation on cytotoxicity of a new nano-hydroxyapatite as root canal filling sealer / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluated the cytotoxicity of a new nano-hydroxyapatite (n-HA) root canal sealer.</p><p><b>METHODS</b>In this study, the cytotoxicity was evaluated by the method of MTT assay in vitro, and culture medium F12 as control, three concentrations of the soaking material cultured with mouse osteoblast separately, to test the cell relative growth rate (RGR) of every group.</p><p><b>RESULTS</b>The toxicity graduation of the n-HA root canal sealer tends to 0 with the culture time increasing. The cell survival rate of n-HA root canal sealer showed high relatively. The OD value of cell was similar for the negative control and the extracts (P > 0.05).</p><p><b>CONCLUSION</b>The result indicated that n-HA root canal sealer was compatible with the testcells.</p>