Drought and low temperature-induced NF-YA1 activates FT expression to promote citrus flowering.

Flower induction in adult citrus is mainly regulated by drought and low temperatures. However, the mechanism of FLOWERING LOCUS T regulation of citrus flowering (CiFT) under two flower-inductive stimuli remains largely unclear. In this study, a citrus transcription factor, nuclear factor YA (CiNF-YA1), was found to specifically bind to the CiFT promoter by forming a complex with CiNF-YB2 and CiNF-YC2 to activate CiFT expression. CiNF-YA1 was induced in juvenile citrus by low temperature and drought treatments. Overexpression of CiNF-YA1 increased drought susceptibility in transgenic citrus, whereas suppression of CiNF-YA1 enhanced drought tolerance in silenced citrus plants. Furthermore, a GOLDEN2 - LIKE protein (CiFE) that interacts with CiFT protein was also isolated. Further experimental evidence showed that CiFE binds to the citrus LEAFY (CiLFY) promoter and activates its expression. In addition, the expressions of CiNF-YA1 and CiFE showed a seasonal increase during the floral induction period and were induced by artificial drought and low-temperature treatments at which floral induction occurred. These results indicate that CiNF-YA1 may activate CiFT expression in response to drought and low temperatures by binding to the CiFT promoter. CiFT then forms a complex with CiFE to activate CiLFY, thereby promoting the flowering of adult citrus.

Severe chemosis and treatment following fronto-orbital advancement surgery for Crouzon syndrome: A case report.

RATIONALE: Crouzon syndrome is a craniofacial malformation caused by premature fusion of fibrous sutures in infants. It is one of the most common craniosynostosis syndromes, and surgery is the only effective treatment for correcting it. Postoperative complications such as encephalocele, infections, hematoma have been reported. We herein report a case of a 62-month-old boy with Crouzon syndrome who underwent fronto-orbital advancing osteotomy, cranial vault remolding, and extensive osteotomy and subsequently developed left proptosis and severe chemosis, these complications are rare and we believe it will be of use to clinicians, physicians, and researchers alike. PATIENT CONCERNS: The patient's skull had been malformed since birth, and he had been experiencing paroxysmal headaches coupled with vomiting for 4 months. Having never received prior treatment, he underwent fronto-orbital advancement at our clinic; afterward, left proptosis and severe chemosis occurred. DIAGNOSIS: The patient was diagnosed with Crouzon syndrome, and the complications included left proptosis and severe chemosis, confirmed by the clinical manifestations, physical examination, and computed tomography (CT). INTERVENTION: We carried out cranial vault remodeling and fronto-orbital advancement. We applied ophthalmic chlortetracycline ointment on the conjunctivae, elevated the patient's head, evacuated the hematoma, and carried out a left blepharorrhaphy. OUTCOMES: The proptosis and chemosis resolved with no recurrence. No other complications occurred during the follow-up period (12 months), and CT scans revealed that the hematoma had disappeared. The calvarial vault reshaping was satisfactorily performed, and the patient's vision was not impaired. LESSONS: Severe proptosis and chemosis are rare complications that can occur after fronto-orbital advancement for Crouzon syndrome. A detailed preoperative examination (including magnetic resonance imaging and CT) is essential for diagnosis. Complete hemostasis, evacuation of hematoma, and placement of a periorbital drainage tube during surgery all contribute to an effective treatment plan. An ophthalmic ointment should be administered, and the patient's head should be elevated during the procedure. Evacuation of retrobulbar epidural hematoma and blepharorrhaphy could also help relieve proptosis and chemosis. Our report describes 2 rare complications associated with the treatment for Crouzon syndrome, and we believe it will be of use to clinicians, physicians, and researchers alike.

Anti-Tumor Mechanisms Associated With Regulation of Non-Coding RNA by Active Ingredients of Chinese Medicine: A Review.

Cancer has become the second leading cause of death worldwide; however, its complex pathogenesis remains largely unclear. Previous research has shown that cancer development and progression are closely associated with various non-coding RNAs, including long non-coding RNAs and microRNAs, which regulate gene expression. Target gene abnormalities are regulated and engaged in the complex mechanism underlying tumor formation, thereby controlling apoptosis, invasion, and migration of tumor cells and providing potentially effective targets for the treatment of malignant tumors. Chemotherapy is a commonly used therapeutic strategy for cancer; however, its effectiveness is limited by general toxicity and tumor cell drug resistance. Therefore, increasing attention has been paid to developing new cancer treatment modalities using traditional Chinese medicines, which exert regulatory effects on multiple components, targets, and pathways. Several active ingredients in Chinese medicine, including ginsenoside, baicalin, and matrine have been found to regulate ncRNA expression levels, thus, exerting anti-tumor effects. This review summarizes the scientific progress made regarding the anti-tumor mechanisms elicited by various active ingredients of Chinese medicine in regulating non-coding RNAs, to provide a theoretical foundation for treating tumors using traditional Chinese medicine.

Identification of the Genetic Variation and Gene Exchange between Citrus Trifoliata and Citrus Clementina.

To identify the genetic variation between Citrus trifoliata and Citrus clementina, we performed genome resequencing on the two citrus species. Compared with the citrus reference genome, a total of 9,449,204 single-nucleotide polymorphisms (SNPs) and 846,615 insertion/deletion polymorphisms (InDels) were identified in the two citrus species, while 1,868,115 (19.77%) of the SNPs and 190,199 (22.47%) of the InDels from the two citrus species were located in the genic regions. Meanwhile, a total of 8,091,407 specific SNPs and 692,654 specific InDels were identified in the two citrus genotypes, yielding an average of 27.32 SNPs/kb and 2.34 InDels/kb. We identified and characterized the patterns of gene exchanges in the grafted citrus plants by using specific genetic variation from genome resequencing. A total of 4396 transporting genes across graft junctions was identified. Some specific genetic variation and mobile genes was also confirmed by Sanger sequencing. Furthermore, these mobile genes could move directionally or bidirectionally between the scions and the rootstocks. In addition, a total of 1581 and 2577 differentially expressed genes were found in the scions and the rootstocks after grafting compared with the control, respectively. These genetic variations provide fundamental information on the genetic basis of important traits between C. trifoliata and C. clementina, as the transport of genes would be applicable to horticulture crops.

A New Technique for Sagittal Synostosis: A Plurality of Small Incisions Minimally Invasive Technique Used on Infants and Young Patients.

OBJECTIV: The authors devised a multiple small incisions minimally invasive technique for use in isolated nonsyndromic sagittal synostosis to achieve better esthetic effect and satisfactory reshaping of the calvarial vault. The purpose of this study is to provide clinicians with new and feasible solution. METHODS: From April 2016 to January 2017, 5 male patients were successfully treated with minimally invasive surgery. The age ranges from 1.5 to 3.3 years. The authors designed 9 short skin linear incisions (2-3 cm long) strategically to disperse in the scalp. The patient was assessed in a series including sex, age of surgery, blood loss, blood transfusion, duration of surgery, postoperative complications, preoperative and postoperative cephalic index (CI), length of stay (LOS), esthetic outcomes, and intellectual developmental quotient (DQ). RESULTS: The shortest operation time is 1.5 hours. The shortest hospital stay is 6 days. The blood loss ranged from 135 to 280 mL. No serious complications occurred during the follow-up time. Postoperative 3-dimensional CT scan showed that the extensive floating bone formed well. Preoperative CI ranged from 64.2 to 68 and postoperatively 69.4 to 74.3. Mental development was tested by children heath care practioners, significantly improving DQ from 67 to 81 preoperatively and 76 to 90 postoperatively. All children receive good esthetic results. CONCLUSION: The new technique is safe and effective. The advantages are satisfactory: calvarial fornix remodeling, less visible appearance of scars, shorter length of surgery, lower mental and financial stress, optimal age for surgery, no endoscopic adjuvant and postoperative helmet are needed.

Genome-wide genetic variation and comparison of fruit-associated traits between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina).

KEY MESSAGE: The comprehensive genetic variation of two citrus species were analyzed at genome and transcriptome level. A total of 1090 differentially expressed genes were found during fruit development by RNA-sequencing. Fruit size (fruit equatorial diameter) and weight (fresh weight) are the two most important components determining yield and consumer acceptability for many horticultural crops. However, little is known about the genetic control of these traits. Here, we performed whole-genome resequencing to reveal the comprehensive genetic variation of the fruit development between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina). In total, 5,865,235 single-nucleotide polymorphisms (SNPs) and 414,447 insertions/deletions (InDels) were identified in the two citrus species. Based on integrative analysis of genome and transcriptome of fruit, 640,801 SNPs and 20,733 InDels were identified. The features, genomic distribution, functional effect, and other characteristics of these genetic variations were explored. RNA-sequencing identified 1090 differentially expressed genes (DEGs) during fruit development of kumquat and Clementine mandarin. Gene Ontology revealed that these genes were involved in various molecular functional and biological processes. In addition, the genetic variation of 939 DEGs and 74 multiple fruit development pathway genes from previous reports were also identified. A global survey identified 24,237 specific alternative splicing events in the two citrus species and showed that intron retention is the most prevalent pattern of alternative splicing. These genome variation data provide a foundation for further exploration of citrus diversity and gene-phenotype relationships and for future research on molecular breeding to improve kumquat, Clementine mandarin and related species.

[Study of the correlation between moderately and severely chronic periodontitis and coronary heart disease].

OBJECTIVE: To investigate the correlation between moderately and severely chronic periodontitis and coronary heart disease, as well as the role of fibrinogen in the mechanisms responsible for the correlation between periodontitis and coronary heart disease. METHODS: 95 subjects who were systemic health or patients of coronary heart disease with or without periodontitis were enrolled. All the subjects were placed into 4 groups based on their periodontal status and cardiovascular health. The 4 groups were healthy control group (HC), moderately and severely chronic periodontitis group (MSP), coronary heart disease group(CHD), and MSP coexisted with CHD group (MSP+CHD). Clinical periodontal index were examined, at the same time, plasma fibrinogen levels and serological changes used in diagnosing of cardiovascular disease routinely were determined. ANOVA and ANCOVA were used in the statistical analysis. RESULTS: Fibrinogen levels of HC, MSP, CHD, and MSP+CHD group were (2.36+/-0.37), (3.63+/-0.73), (4.08+/-0.84), and (4.14+/-0.96) g/L, respectively. Fibrinogen levels of MSP and MSP+CHD group were significantly higher than that of healthy controls (P<0.01). The patients with moderately to severely chronic periodontitis were more likely to have coronary heart disease as compared to periodontally healthy controls (OR=2.527, P=0.047) after adjusted for blood pressure and body mass index. CONCLUSION: Moderately and severely chronic periodontitis maybe a risk factor of coronary heart disease and fibrinogen could be one of the biological basis which links periodontitis with coronary heart disease.

[Correlation between levels of fibrinogen, beta455 g/A fibrinogen gene polymorphism and chronic periodontitis].

OBJECTIVE: To investigate the relationship between plasma levels of fibrinogen, the-beta455 G/A fibrinogen gene polymorphism and the severity of periodontal inflammation and to explore the possible role of fibrinogen in the association of periodontitis with coronary heart disease (CHD). METHODS: A total of 121 patients with moderate to severe periodontitis and periodontally healthy and gingivitis controls were enrolled in the study. Peripheral blood samples were collected and the plasma fibrinogen levels were determined by the clotting method of Clauss. Polymerase chain reaction and restriction fragment length polymorphism analysis with Hae III were used to examine the -beta455 G/A fibrinogen gene polymorphism. RESULTS: Fibrinogen levels were significantly higher in moderately or severely chronic periodontitis patients [(3.45 +/- 0.68) g/L] than periodontally healthy and gingivitis controls [(2.47 +/- 0.42) g/L, P < 0.001]. The carrier status of the A allele at position -455 in the beta fibrinogen gene was associated with elevated fibrinogen levels and the frequency of the-A455 allele in the beta fibrinogen gene in the patient group was significantly higher than in the control group (P = 0.032). Carriers of the -A455 allele were about 3-fold more likely to have moderate or severe periodontitis as compare to individuals without the -A455 allele( OR = 3. =135, P= 0.008). CONCLUSIONS: Fg-beta455 G/A polymorphism may contribute to the elevated plasma fibrinogen levels and put individuals at higher risk of having severe periodontitis. As the independent risk factor of CHD, fibrinogen levels and Fg-beta455 G/A polymorphism may play a role in the pathogenesis of periodontitis.

[Effect of fibrinogen on the secretion of interleukin-1beta and - 8 by polymorphonuclear leukocytes].

OBJECTIVE: To investigate the effect of one of the acute-phase proteins, fibrinogen, on the release of IL-1beta and -8 by human peripheral polymorphonuclear leukocytes (PMN) and the possible role of fibrinogen during the destruction of periodontium. METHODS: Peripheral PMN were isolated by discontinuous density gradient centrifuging technique. The freshly isolated PMN were suspended in Hank's balanced saline solution (1 x 10(9)/L) supplemented with 0.5% BSA and 0.1% glucose. The levels of IL-1beta and -8 in the supernatants produced by cultured cells upon the addition of human fibrinogen at different concentrations were measured by ELISA technique. RESULTS: Incubated with human fibrinogen at 2 g/L or 10 g/L for different time periods, human peripheral PMN released significantly greater amount of IL-1beta [(10.41 +/- 0.37) - (35.86 +/- 0.30) ng/L or (22.81 +/- 0.45) - (57.77 +/- 2.08) ng/L] and IL-8 [(93.90 +/- 13.95) - (2045.66 +/- 53.03) ng/L or (115.02 +/- 10.61) - (3858.69 +/- 25.65) ng/L] than PMN without the stimulation of fibrinogen (IL-1beta, P < 0.001, and IL-8, P < or = 0.016). The higher concentration of fibrinogen or the longer treatment time, the higher levels of IL-1beta and -8 were released by PMN (P < 0.001). CONCLUSIONS: Fibrinogen induced the secretion of pro-inflammatory cytokines IL-1beta and -8 by PMN and may be involved in magnification of the inflammatory response of periodontium and bone resorption.

[Clinical evaluation of composite inlays in defective molars].

OBJECTIVE: To evaluate clinical effect of composite inlays in the defective molars. METHODS: A total of 200 defective molars from 163 patients were divided into two groups, including 100 molars of each. One group was restored with the direct composite inlays and another group with the traditional composite fillings. All the restorations were evaluated in oral cavity after 6-month and 5-year filling or insertion with United States public health service criterions. The data were analyzed using SPSS 11.0 software with the chi-square test. The significance level was set at 5%. RESULTS: In clinical service for 6 months, the successful rate of composite inlays was 91.8% (90/98) and the corresponding figure for traditional composite fillings was 91.8% (89/97), but there was no statistically significant difference (P > 0.05). In clinical service for 5 years, the successful rate of composite inlay was 87.9% (80/91), the corresponding figure for the traditional composite fillings being 67.4% (60/89) and the difference was statistically significant (P < 0.05). CONCLUSIONS: In clinical, the defective molars can be well restored with the direct composite inlays. Especially in the long-term clinical service, the composite inlays show significant superiority over the traditional composite fillings.

[Interleukin-8 regulations of oral epithelial cells by porphyromonas gingivalis with different fimA genotypes].

OBJECTIVE: The expression of heterogenic virulence properties depends on its clonal diversity. The aim of the study was to investigate the mechanism of interleukin-8 (IL-8) regulations of oral epithelial cells by challenge of Porphyromonas gingivalis (P. gingivalis) with different fimA genotypes, discuss the relation between fimA genotype and its pathogenicity. METHODS: P. gingivalis ATCC 33277 (type I), W83 (type IV), 47A-1 (type IV) were assessed for their inductions of IL-8 expression in human oral epithelial cells (KB cell line, ATCC CCL-17). KB cells without stimulation of P. gingivalis were used as control group. IL-8 mRNA expression was de termined by reverse transcription polymerase chain reaction (RT-PCR) at different time intervals (1, 3, 6, 24 h) following continuous co culture of bacteria with KB cell line, and IL-8 protein levels in culture supernatant was determined by enzyme-linked immunosorbent assay. RESULTS: IL-8 mRNA levels were up-regulated and reached its high peak at 1 h following both genotypes infection, then decreased to base level till 24 h. Attenuation of IL-8 protein levels was down-regulated when KB cell co-cultured with both genotypes for 3 h till 24 h, and type IV was lower than type I. IL-8 and IL-6 mRNA expression were not consistent with their protein levels, which indicated post-transcriptional regulations. CONCLUSION: fimA genotypes of P. gingivalis are related with the effect of IL-8 inductions, which indicates fimA genotype is associated with pathogenesis of P. gingivalis.

[Differential analyses of mRNA expression of gtfs from Streptococcus mutans in different pH condition].

OBJECTIVE: To determine the expression level of each gtf under different pH cultural conditions and to find the relationship between gtf expression levels with environmental pH in different strains of Streptococcus mutans (S.mutans). METHODS: S. mutans form clinical isolation with different extracellular polysaccharides (EPS) producibility and UA159 were selected. Their ability to produce EPS under pH5.5 and pH7 were tested. Then in two strains, the relative quantity of gtfA, gtfB, gtfC, gtfD's mRNA which were related to S. mutan's ability to produce EPC, were examined by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) methods under different pH culture condition. RESULTS: At pH5.5, expression levels of gtfA, gtfB, gtfD were increased while that of gtfC were decreased in both strains, and that of gtfB, gtfC were higher in strain which produces more ECP. CONCLUSION: The expression levels of gtfs related closely to the cariogenicity of S. mutan.

[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. METHODS: 38 S. mutans strains included 18 high acid tolerance strains and 20 low acid tolerance strains. Gene uncEBF of these isolates were amplified with specific primers from S. mutans genomic DNA, and the PCR products were analyzed by RFLP and sequenced. SPSS 11.0 statistic software assayed the results. RESULTS: It was testified that two genotypes A and B of PCR-RFLP were revealed when digested with Alu I and Dde I digested fragments of uncEBF displayed two different patterns C and D. Fisher exact two-tail test showed that the distributions of A and B genotype strains with different acidurance were different (P < 0.05), and the proportion of A genotype strains from high acidurance group was higher than that from low acidurance one. Some of these amplified uncEBF genes from different genotype were sequenced and testified that there existed variation of Alu I and Dde I recognized sites. CONCLUSION: This study indicated that uncEBF gene of S. mutans F-ATPase obviously exhibited genetic diversity.

[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. mutans strains derived from caries-active and caries-free individuals including 18 strains displaying high acid tolerance and 20 strains displaying low acid tolerance. Gene uncG was amplified with specific primers from S. mutans genomic DNA, then the PCR product was analyzed by RFLP and sequenced. The relative expression quantity of uncG gene against the housekeeping gene recA was determined by using RT-PCR method. A gel documentation system and QUANTITY ONES software were used to analyze the data results. RESULTS: It was testified that four genotypes A, B, C and D of PCR-RFLP were revealed when respectively digested with Alu I and Bsr I, but the distributions of the four genotype strains showed no difference (P > 0.05). The differences of uncG gene transcript quantities derived from different genotype or different aciduranc strains had no significance (P > 0.05). CONCLUSION: This study indicated that uncG gene of F-ATPase obviously displayed genetic diversity and existed polymorphism at mRNA expression level, while the Alu I-RFLP genotypes and the expression levels would not be responsive to different acid tolerance of S. mutans strains.

[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. Differences in cariogenic abilities of S. mutans isolates may be determined by genetic heterogeneity from virulent factors. The relationship between LDH activity or genetic diversity and cariogenicity of S. mutans (serotype c) isolates was studied in this research. METHODS: The genome DNA of S. mutans isolates were isolated and LDH gene (ldh) were amplified with specific primers. These isolates came from 34 caries-active individuals and 36 caries-free ones, in which 24 strains showed the high LDH activity and 21 strains showed the low LDH activity. Then genetic diversity of PCR products were analyzed or assessed by restriction fragment-length polymorphism (RFLP). Some of amplified LDH genes from different group were sequenced and assayed. RESULTS: It is testified that two genotypes A and B of ldh-RFLP were revealed when LDH genes were digested with Mse I, but Hph I, Mnl I, Dde I, Nla III and Alu I digesting fragments of Idh gene did not show different pattern. Furthermore, Fisher Exact one-Tail Test showed that the proportion of genotype B among strains from caries-free individuals was higher than that from caries-active ones (P = 0.033), while the distribution of genotypes with different LDH activity was different between two groups (two-Tail Test P = 0.017). The sequencing DNA testified that the specific base mutation would lead to multiple kind of genotype resulted. CONCLUSION: This study indicated that LDH gene of S. mutans clinical strains from different individuals is conservative, while there still is the gene mutation in. The ldh genetic diversity may be related to the low caries sensitivity, and closely correlated with the differences in LDH enzyme activity of S. mutans strains.

[Homology analysis of the extended-V region of the surface proteins in different serotype Streptococcus mutans].

OBJECTIVE: To analysis the homology among the extended-V region of the surface proteins in different serotype Streptococcus mutans (c, f, d, g) and to find out it's significance in anti-caries vaccine. METHODS: The DNA of the bacteria (standarded serotype c, d, f, g and partial serotype c clinicals) was extracted and the extended-V region (SrV+, 1 384-2 514 bp) was amplified using polymerase chain reaction (PCR). Then the products were assessed using restriction fragment length polymorphism (RFLP) by endonuclease Dde I. The genotypings were sequenced and analysised using the program of BLAST on NCBI Gene Bank database. RESULTS: About 1.13 kb fragments were produced both in serotype c and f, the serotype d and g were failed. The RFLP results showed that five different patterns(A, B, C, D, E) among the 117 PCR products were reveled by Dde I. The ration of the genotypings A and B were the most among the strains, the C was lower, the D and E respectively was 1 and 3 strains per genotype. OMZ175 (serotype f) was belong to B genotype. Selected one of the A, B, C genotypings to sequenced and blasted. Then the results of the blastn showed that the identities of the gene sequence were 92%-98% between the serotype c and serotype f, part sequence of the serotype g was homology with the SrV+ of the serotype c, the protein sequence among serotype c, d, f, g were 77%-82%. CONCLUSION: It is reasonable to use some putative pipetides to study the anti-caries vaccine among the extended-V regions of the surface proteins in different serotype (c, d, f, g) in S. mutans.

[Study on the genetic diversity within the extended-V region of the surface protein of Streptococcus mutans].

PURPOSE: The purpose of this study was to investigate the genicity of the extended- variable region (V+) of surface proteins of Streptococcus mutans (S. mutans, serotype c,f) and provide some genetic informations on the molecular structure of S. mutans surface protein. METHODS: 7 standard strains and 110 clinical isolates of S.mutans were selected.The bacterial DNA was extracted and the extended-V region (srV+ 1384-2514 bp) was amplified using polymerase chain reaction (PCR). The genetic diversity of srV+ was assessed by using restriction fragment length polymorphism (RFLP) with restriction endonuclease DdeI. RESULTS: The results showed that five different patterns (A,B,C,D,E) of the PCR-RFLP among the 117 strains were reveled by DdeI. The ration of the genotype A and B were the most among the strains, C followed by genotype, the D and E were 1 and 3 strains per genotype, respectively.OMZ175 (serotype f) belonged to B genotype. CONCLUSIONS: The study supported that the extended-variable region (srV+) of the surface proteins of Streptococcus mutans have diversity. There are five patterns of genotypings. The most genotypings were p1-like,spaP /sr-like and pac-like.

[The expression and activity of alkaline phosphatase in human periodontal ligament cells with nanometer hydroxyapatite].

OBJECTIVE: To investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC). METHODS: Nano-hydroxyapatite powders were fabricated with sol-gel method. The fourth passage periodontal ligament cells were cultured with nanometer hydroxyapatite powder (nano-HA), dense hydroxyapatite powder (dense-HA) and only medium as control respectively. On the 5th, 8th day of culture, the osteogenetic differentiation of human periodontal ligament cells was evaluated though alkaline phosphatase (ALP) activity, ALP immunohistochemical stain and ALP positive flow cytometry. RESULTS: There were significant differences among nano-HA group, dense-HA group and control group on the 5th and 8th day of culture. A majority of nano-HA group and dense-HA group cells sample showed positive ALP stain. But the ALP positive stain of nano-HA group cells sample was denser than that of dense-HA group. In FCM, the distribution of ALP positive cells cultured with nanoparticles were significantly more than that of other groups. CONCLUSIONS: The nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.

[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. METHODS: Sixty-four S. mutans strains derived from 34 caries-active individuals and 30 caries-free individuals, including 18 strains displaying high acid tolerance and 20 strains displaying low acid tolerance. Gene uncA was amplified with specific primers from S. mutans genomic DNA, then the PCR products were analyzed by RFLP and sequenced. RESULTS: Two genotypes A and B of PCR-RFLP were revealed when digested with Hph I. Mbo II also produced two different pattern C and D. The distributions of A and B genotype strains with different caries-sensitivity groups were different (P < 0.05), and the proportion of A genotype strains from caries-activity group was higher than that from caries-free one. The distributions of C and D genotype strains with different acidurance strains were different (P < 0.05), and the proportion of C genotype strains from high acid tolerance group was higher than that from low acid tolerance group. These amplified uncA genes from different group were sequenced and there existed variation of Hph I and Mbo II recognized sites. CONCLUSIONS: This study indicates that uncA gene of S. mutans F-ATPase obviously displayed genetic diversity. The different Hph I-RFLP and Mbo II-RFLP genotypes could be related to the cariogenicity and acid tolerance of S. mutans strains.

[Effect of fibrinogen on the adherence of Porphyromonas gingivalis to human oral epithelial cells].

OBJECTIVE: To study the role of fibrinogen molecule in the pathogenesis of periodontal diseases. METHODS: An in vitro cell culture model was used. Methyl-(3)H Thymidine radiolabeled Porphyromonas gingivalis (Pg) ATCC 33277 were examined for their ability to adhere to and invade the confluent monolayers of human oral epithelial KB cells with or without exogenous human fibrinogens by scintillation spectrometry. RESULTS: The addition of exogenous fibrinogens made more amount of and higher ratios of adhesive and invasive Pg, in contrast to the group without exogenous fibrinogen (P < 0.001). At different concentrations of exogenous fibrinogen, the amount and ratios of adhesive and invasive Pg varied significantly (P < or = 0.007). The higher concentrations of exogenous fibrinogen was added, the greater amount and ratios of adhesive and invasive Pg were found. CONCLUSIONS: Fibrinogen promotes the adherence of Pg to human oral epithelial cells and may play an important role in the pathogenesis of periodontal diseases.