Inhibition of RhoGEF/RhoA alleviates regorafenib resistance and cancer stemness via Hippo signaling pathway in hepatocellular carcinoma.

Patients with hepatocellular carcinoma (HCC) are vulnerable to drug resistance. Although drug resistance has been taken much attention to HCC therapy, little is known of regorafenib and regorafenib resistance (RR). This study aimed to determine the drug resistance pattern and the role of RhoA in RR. Two regorafenib-resistant cell lines were constructed based on Huh7 and Hep3B cell lines. In vitro and in vivo assays were conducted to study RhoA expression, the activity of Hippo signaling pathway and cancer stem cell (CSC) traits. The data showed that RhoA was highly expressed, Hippo signaling was hypoactivated and CSC traits were more prominent in RR cells. Inhibiting RhoA could reverse RR, and the alliance of RhoA inhibition and regorafenib synergistically attenuated CSC phenotype. Furthermore, inhibiting LARG/RhoA increased Kibra/NF2 complex formation, prevented YAP from shuttling into the nucleus and repressed CD44 mRNA expression. Clinically, the high expression of RhoA correlated with poor prognosis. LARG, RhoA, YAP1 and CD44 show positive correlation with each other. Thus, inhibition of RhoGEF/RhoA has the potential to reverse RR and repress CSC phenotype in HCC.

Garnet secondary ion mass spectrometry oxygen isotopes reveal crucial roles of pulsed magmatic fluid and its mixing with meteoric water in lode gold genesis.

SignificanceThere is a common consensus that lode gold deposits mostly precipitated from metamorphic fluids via fluid boiling and/or fluid-rock interaction, but whether magmatic hydrothermal fluids and the mixing of such fluids with an external component have played a vital role in the formation of lode gold deposits remains elusive. We use garnet secondary ion mass spectrometry oxygen isotope analysis to demonstrate that the world-class Dongping lode gold deposit has been formed by multiple pulses of magmatic hydrothermal fluids and their mixing with large volumes of meteoric water. This study opens an opportunity to tightly constrain the origin of lode gold deposits worldwide and other hydrothermal systems that may have generated giant ore deposits in the Earth's crust.

Sonography for diagnosis of benign and malignant tumors of the nose and paranasal sinuses.

OBJECTIVES: The purpose of this study was to demonstrate the reliability of sonography for diagnosis of nose and paranasal sinus tumors. METHODS: Ninety-six consecutive patients with tumors underwent sonography and computed tomography (CT) before surgical treatment. Tumor detectability and imaging findings were evaluated independently and then compared with pathologic findings. RESULTS: Of 96 tumors, 75 were detected by sonography, for a detectability rate of 78.1%; 93 tumors were detected by CT, for a detectability rate of 96.9%. By comparison, sonography showed a trend toward higher detectability of nasal vestibular tumors than CT (87.5% for sonography versus 50.0% for CT) and small lumps on the wing of the nose (78.8% for sonography versus 33.3% for CT). Among the sonographic features, boundary, shape, internal echo, calcification, bone invasion, vascular pattern, and cervical lymph node metastasis all had significantly positive correlations with malignancy (P < .05), but size did not (P = .324). In addition, the vascular resistive index for malignant tumors was significantly higher (mean ± SD, 0.66 ± 0.20) than the index for benign lesions (0.24 ± 0.30; P < .001). Moreover, the detection rate for grade 1-3 (small-large) blood flow in benign lesions was only 43.8%, whereas the rate for malignant tumors was 97.7% (P < .001). CONCLUSIONS: The vascular pattern may be a promising predictive indicator for distinguishing benign and malignant tumors of the nose and paranasal sinuses. Consequently, sonography has high value for diagnosis of benign and malignant tumors of the nose and paranasal sinuses, especially for nasal vestibular tumors and small lumps on the wing of the nose.

Sonographic findings of nasopharyngeal carcinoma and its involvement in the parapharyngeal space.

OBJECTIVES: The purpose of this study was to determine the sonographic performance in pathologically proven cases of nasopharyngeal carcinoma and its involvement in the parapharyngeal space. METHODS: The study included 58 patients being treated for suspected nasopharyngeal carcinoma detected by routine nasopharyngoscopy who underwent pathologic biopsy. Sonography was performed immediately thereafter with a convex array transducer in both the B-mode and color mode. Forty-five of the 58 patients (90 parapharyngeal spaces) in whom nasopharyngeal carcinoma was proved by both sonography and pathologic biopsy underwent preradiotherapy magnetic resonance imaging (MRI). The sonographic findings were compared to the pathologic findings. The sonographic findings of parapharyngeal space involvement were correlated with the MRI findings. RESULTS: The normal anatomy of the nasopharynx and parapharyngeal space, nasopharyngeal carcinoma, and its relationship with the parapharyngeal space were well shown on sonography. The sensitivity of sonography for detection of nasopharyngeal carcinoma was 97.8%, and the specificity was 41.7%. The sonographic findings of parapharyngeal space involvement had a high degree of agreement with MRI (κ = 0.757; P < .001). CONCLUSIONS: These promising initial data indicate that sonography may be a useful tool for diagnosing nasopharyngeal carcinoma and defining the relationship between the tumor and the parapharyngeal space.

Early administration of dobutamine in the treatment of septic shock patients with tumor-a retrospective comparative cohort study.

Background: Studies have found that dobutamine may be beneficial to protect organs function in patients with septic shock, but there is still a lack of relevant research in septic shock patients with tumor. The study sought to explore the role of the early administration of dobutamine in the treatment of septic shock patients with tumors. Methods: We retrospectively collected the data of tumor patients who developed septic shock at Sun Yat-sen University Cancer Center between June 2008 and November 2021. All the patients were divided into the following 3 groups: (I) the early administration group (<3 days, n=15); (II) the late administration group (≥3 days, n=22); and (III) the non-administration group (n=85). The primary observation indicator was 28-day mortality, and the secondary observation indicators included the shock reversal rate, the length of stay in the intensive care unit (ICU) and the duration of mechanical ventilation. There was no statistical difference in the basic data of the three groups. Results: The early administration group had a significant decrease in 28-day mortality compared to the late and non-administration groups (log-rank P=0.018). The comparison between the groups showed that the 28-day mortality of the early administration group was significantly lower than that of the non-administration group [20.0% vs. 58.8%, P=0.013, hazard ratios (HRs) =0.248, 95% confidence intervals (CIs): 0.077-0.796]. There was no statistically significant difference in 28-day mortality between the late administration group and the non-administration group (63.6% vs. 58.8%, P=0.682, HR =0.983, 95% CI: 0.543-1.778). Additionally, the early administration group had a significantly increased shock reversal rate (P=0.014), shortened length of stay in the ICU (P<0.001), and reduced duration of mechanical ventilation (P=0.049). Conclusions: Early use of dobutamine may be beneficial to reduce the in-hospital mortality of septic shock patients with tumor, but the sample size of this study was small, which still needs to be confirmed by a multi-center randomized controlled clinical study.

Clinical study of periodontal endoscope-assisted subgingival scaling in the treatment of residual pocket.

OBJECTIVES: To compare the treatment effects of periodontal endoscope-assisted and traditional subgingival scaling on residual pockets. METHODS: A total of 13 patients with periodontitis from Dept. of Periodontics, West China Hospital of Stomatology, Sichuan University were recruited. After 4-6 weeks of initial treatment, the residual pockets with a probing depth (PD) of ≥4 mm and attachment loss (AL) of ≥4 mm and bleeding on probing were examined with traditional (control group) and periodontal endoscope-assisted subgingival scaling (endoscopy group) in a randomly controlled split-mouth design. At baseline and 6 weeks and 3 months after treatment, plaque index (PLI), PD, AL, and bleeding index (BI) were measured. Differences in these clinical parameters within and between groups and patient-reported outcomes were compared. RESULTS: A total of the 694 sites of 251 teeth were included in this trial. Both groups showed significant improvement in each periodontal parameters 6 weeks and 3 months after treatment (P<0.001). For sites in a single-rooted tooth, sites with PD≥5 mm, and sites without vertical alveolar bone resorption and furcation involvement, the PD in endoscopy group was significantly lower than that in the control group at 6 weeks and 3 months after treatment (P<0.05). CONCLUSIONS: Periodontal endoscope-assisted subgingival scaling resulted in better effects than traditional subgingival scaling when the residual pockets were in a single-rooted tooth, with a PD of ≥5 mm but without vertical alveolar bone resorption and furcation involvement.

Research progress on two-component signal transduction systems in Porphyromonas gingivalis.

Porphyromonas gingivalis (P. gingivalis), a Gram-negative oral anaerobe, is considered to be a major pathogenic agent involved in the onset and progression of chronic periodontitis. P. gingivalis must be able to perceive and respond to the complicated changes in host to survive the environmental challenges, in which the two-component signal transduction systems (TCSs) play critical roles by connecting input signals to cellular physiological output. Canonical TCS consists of a sensor histidine kinase and a cognate response regulator that functions via a phosphorylation cascade. In this review, the roles of TCSs in P. gingivalis were demonstrated by illustrating the target genes and modulation modes, which may help elucidate the underlying mechanisms in future studies.

[Role of bone morphogenetic protein 1/tolloid proteinase family in the development of teeth and bone].

The bone morphogenetic protein (BMP) 1/tolloid (TLD) proteinase family is a group of important metalloproteinases, which play key roles in the growth and development of tissues and organs via regulating the biosynthetic processing of the extracellular matrix. Clinical reports have revealed that mutations in the genes encoding BMP1/TLD proteinases lead to dentinogenesis imperfecta type Ⅰ, accompanied with osteogenesis imperfecta. Therefore, this proteinase family is essential for the development of hard tissues. In this study, we review the research progress in the function and mechanism of the BMP1/TLD proteinase family in the development of teeth and bone.

[Treatment strategy for pregnancy epulis].

Pregnancy epulis is a tumor-like lesion with high prevalence in China. The local lesion, the general condition of the pregnant patient, and the complications during treatment should be taken into consideration when making a treatment plan for pregnancy epulis. In this study, three representative pregnancy epulis cases were presented, and related studies at home and aboard were reviewed to summarize the etiology, differential diagnosis, treatment, and prevention of pregnancy epulis and share the clinical experience in the treatment of pregnancy epulis.

[Research progress on substitutes for autogenous soft tissue grafts in mucogingival surgery].

Mucogingival surgery is a general term for periodontal surgeries that correct aberrant periodontal soft tissues. Conventional mucogingival surgeries with pedicle flap or autologous soft tissue graft for treatment of gingival recession and insufficient keratinized tissues are always related to disadvantages such as need for a second surgery site, limited supplies, and complaints for postoperative discomfort. In this regard, research and application of soft tissue substitutes have gained increasing attention. Various kinds of soft tissue substitutes, including acellular dermal matrix and xenogeneic collagen matrix, have been developed and applied to clinical treatment. This review aims to summarize advances in research of the characteristics and clinical effectiveness of several soft tissue substitutes and provide references for clinical application.

[Expression of triggering receptors expressed by myeloid cells-1 in macrophages stimulated by Porphyromonas gingivalis-lipopolysaccharide].

OBJECTIVE: Soluble triggering receptors expressed by myeloid cells-1 (sTREM-1) and inflammatory cytokine tumor necrosis factor-α (TNF-α) in macrophage cells were stimulated by Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) to investigate the expression of triggering receptors expressed by myeloid cells-1 (TREM-1) and further explore the correlation between TREM-1 and the pathogenesis of periodontitis. METHODS: THP-1 cells (a human monocytic cell line derived from an acute monocytic leukemia patient) were induced to differentiate THP-1 macrophages by phorbol-12-myristate-13-acetate and were injected with 0 (blank control), 0.5, or 1.0 µg·mL⁻¹ Pg-LPS. The THP-1 cells were then grouped in accordance with incubation time, and each group was incubated for 4, 6, 12, or 24 h. The expression of the TREM-1 mRNA in macrophages was detected by real-time quantitative polymerase chain reaction, while the expression of TREM-1 protein was detected by Western blot; the site where TREM-1 protein expression was observed in macrophages was detected by immunofluorescence staining, and the expression of soluble sTREM-1 and TNF-α in cell culture medium was detected by enzyme-linked immunosorbent assay. RESULTS: Compared with the blank control group, the expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in Pg-LPS-stimulated macrophages was significantly upregulated (P<0.05). The expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in the supernatant of cell culture was higher in the 1.0 µg·mL⁻¹ Pg-LPS group than in the 0.5 µg·mL⁻¹ group; this expression was statistically significant since the 6, 4, and 4 h time point (P<0.05). Cell immunofluorescence staining showed that TREM-1 protein was positive when the THP-1 macrophages was stimulated by Pg-LPS (1.0 µg·mL⁻¹) for 24 h, and the staining sites of TREM-1 were mainly located in the cell membrane of the macrophages (P<0.05). The expression level of TNF-α increased in groups stimulated by Pg-LPS, and the expression level of TNF-α was significantly higher in 1.0 µg·mL⁻¹ Pg-LPS stimulated groups than in 0.5 µg·mL⁻¹ Pg-LPS-stimulated groups since the 6 h time point (P<0.05). The expressions of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in 0.5 µg·mL⁻¹ Pg-LPS-stimulated macrophages were positively correlated with one another (r=1, P<0.05), but no statistically significant correlation was found in the expression of TNF-α. The positive correlation between sTREM-1 and TNF-α expressions was detected when macrophages were stimulated by 1.0 µg·mL⁻¹ Pg-LPS (r=1, P<0.05). CONCLUSIONS: The expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in the culture supernatant in Pg-LPS-stimulated macrophages was significantly upregulated on the basis of the concentration of Pg-LPS; moreover, their upregulation was positively correlated with one another. The expression of TNF-α in the supernatant of cell culture was also upregulated and was positively correlated with the expression of sTREM-1 at the group of high Pg-LPS concentration (1.0 µg·mL⁻¹). Results reveal that TREM-1, which has been realized as a proinflammatory receptor protein, can promote the development of periodontitis by regulating the expression of TNF-α in macrophages.

[Distribution of fimA genotype of Porphyromonas gingivalis in Chinese periodontitis patients and its relationship with chronic periodontitis].

OBJECTIVE: To investigate the distribution of fimA genotype of Porphyromonas gingivalis in Chinese periodontitis patients and try to find the relationship between fimA genotype and chronic periodontitis. METHODS: Subgingival plaque samples were collected from 101 periodontitis patients. P. gingivalis 16S rRNA primer and fimA type-specific primer were designed. The distribution of fimA genotype in periodontitis patients was detected by PCR. Clinical periodontal indices (PPD, CAL and BOP) were measured at the sample tooth's six points; namely, the mesio-, mid-, distobuccal and mesio-, mid-, distolingual points. RESULTS: P. gingivalis was detected in 89 periodontitis patients (88.1%). Among them, a single fimA genotype was detected in most subgingival plaque samples (65.1%), and the most prevalent fimA genotype was type II (43.8%), followed by type IV (40.4%); Type II fimA and IV fimA were more frequently detected in mild/moderate periodontitis group and severe periodontitis group. CONCLUSION: The findings indicate that P. gingivalis with type II fimA and IV fimA are more predominant in Chinese periodontitis, and the organisms are involved in the destructive progression of periodontitis in Chinese.

[Interleukin-1beta and IL-1 receptor antagonist levels in gingival crevicular fluid and their relationship to clinical indices of periodontitis].

OBJECTIVE: To investigate Interleukin-1beta (IL-1beta) and IL-1 receptor antagonist (IL-1ra) concentrations in gingival crevicular fluid (GCF) of periodontally healthy teeth and to periodontitis teeth and to reveal their relationships to periodontal clinical indices. METHODS: Thirty GCF samples were harvested from periodontally healthy sites in which 15 samples were from periodontally healthy subjects and 15 GCF samples were from patients with chronic periodontitis, and 43 GCF samples (including 28 samples from BOP positive sites and 15 samples from BOP negative sites) were harvested from periodontitis sites of 33 patients with chronic periodontitis. Clinical indices (GI, PPD and CAL) were recorded for each tooth. The concentrations of IL-1beta and IL-1ra in GCF were quantified by ELISA method. RESULTS: (1) The mean concentrations of IL-1beta and IL-1ra and the average value of 10(4)IL-1beta/IL-1ra for periodontally healthy teeth were (61.891 +/- 20.719) pg/ml, (739.410 +/- 249.121) ng/ml and 0.857 +/- 0.375, respectively. The mean concentration of IL-1beta (224.402 +/- 87.416) pg/ml and the average value of 10(4)IL-1beta/IL-1ra for periodontitis teeth 6.813 +/- 0.375 were greater than those for healthy teeth, respectively (P<0.0001), and in contrast, the mean concentration of IL-1ra for periodontitis teeth (366.722 +/- 104.188) ng/ml was lower than that for healthy sites(P<0.0001). (2) For all sites, a strong inverse relationship was found between IL-1beta and IL-1ra levels in GCF (P<0.01). Both of IL-1beta and 10(4) IL-1beta/IL-1ra values had positive correlations with GI, PPD and CAL (P<0.01). And the negative correlation was found between GI and IL-1ra (P<0.05). (3) The mean concentration of IL-1beta and the average value of 10(4)IL-1beta/IL-1ra at BOP positive teeth were greater than those at BOP negative teeth (P<0.0001), and the mean concentration of IL-1ra at BOP positive teeth was lower than that at BOP negative teeth (P<0.01). CONCLUSION: The results suggest that the increasing GCF level of IL-1beta and decreasing level of IL-1ra may be an important factor for the pathogenesis and development of chronic periodontitis and IL-1ra has an inhibitory effect on IL-1beta activity. The GCF level of IL-1beta and the value of 10(4)IL-1beta/IL-1ra, especially the latter one, are closely associated with the clinical indices of chronic periodontitis.

[Effect of Porphyromonas gingivalis lipopolysacchearide on the expression of CC chemokine receptor 2 in monocytes].

OBJECTIVE: To investigate the effects of Porphyromonas gingivalis lipopolysacchearide (Pg-LPS) on the expression of CC chemokine receptor 2 (CCR2) in THP-1 monocyte and to explore the relationship between periodontitis and cardiovascular disease in molecular level. METHODS: THP-1 monocytes were incubated with different concentrations of Pg-LPS (10, 100, 1000 µg/L) for 1, 4 and 24 h respectively, then flow cytometry and reverse transcription-PCR were adopted to determine cell surface protein levels and mRNA levels of CCR2. RESULTS: The protein levels and mRNA levels of CCR2 were higher in all experiment groups of 1 h and 4 h than that in the control group (P < 0.05) , except the protein expression of CCR2 in T1 group of 1 h (55.74 ± 0.96) . The protein expression (52.56 ± 0.61, 40.98 ± 0.86, 26.50 ± 0.67) and mRNA levels (0.095 ± 0.006,0.070 ± 0.004,0.046 ± 0.004) of CCR2 were lower in all experiment groups than that in the control group (56.99 ± 0.44,0.104 ± 0.003) at 24 h (P < 0.05) . The protein levels and mRNA levels of CCR2 were increased in all experiment groups at 4 h and reduced at 24 h (P < 0.05). CONCLUSIONS: Pg-LPS can upregulate CCR2 expression on THP-1 monocyte surface in concentration dependent manner in early stage, promoting the monocyte chemoattractant. Periodontitis may promote atherosclerosis by enhancing monocyte chemoattractant through periodontal pathogens.

Effects of C-reactive protein on CC chemokine receptor 2-mediated chemotaxis of monocytes.

Periodontal infections can increase patients' serum C-reactive protein (CRP) level, which is a predictive marker of future cardiovascular events. Serum CRP may be a key mediator associating periodontitis with cardiovascular disease. It is not yet clarified whether the chemotactic activity of monocytes changes with increased serum CRP. This study investigated the influence of CRP on monocyte chemotaxis and the effects of CRP on CC chemokine receptor 2 (CCR2) expression by monocytes in vitro. Monocyte cell line THP-1 was cultured with human recombinant CRP of different final concentrations, which were 2, 4, 6, 8, and 10 mg/L, respectively. After 24 h incubation, Transwell chambers were applied to analyze the chemotactic activity of pretreated monocytes. Flow cytometry analysis and real-time reverse transcription-polymerase chain reaction (RT-PCR) were applied to detect the CCR2 protein and gene expression levels. In Transwell chambers, more cells were attracted in CRP-pretreated groups than that of blank control with no CRP (p<0.05). The chemotaxis activity was stronger in higher CRP concentration groups than lower ones (p<0.05). The CCR2 protein and mRNA expression was increased in a CRP concentration-dependent manner (p<0.05). CRP stimulation may induce CCR2 overexpression on monocytes and then promote the chemotaxis ability of monocytes. This result suggests that increased serum CRP concentration of periodontitis patients may be associated with high risk of cardiovascular disease.

[Relationship between C-reactive protein gene polymorphaisms and chronic periodontitis].

OBJECTIVE: To investigate the relationship between C-reactive protein (CRP) + 1444C/T, CRP+1059G/C polymorphisms and chronic periodontitis (CP) in a Han Chinese population. METHODS: Clinical periodontal parameters [attachment loss (AL) probing depth (PD) and bleeding on probing (BOP)], and serum CRP levels were examined in CP patients (n = 126) and healthy subjects (n = 113). RESULTS: The mean serum CRP level [(1.74 ± 1.67) mg/L] was significantly higher in the CP group than in the control group [(0.57 ± 0.39) mg/L], P < 0.001. In the control group, serum CRP levels were significantly lower in subjects with the CRP +1059 GC and CC genotypes than those with the CRP +1059 GG genotype (P < 0.01). There was no significant difference between genotypes in the CP group. In CP and the control groups, serum CRP levels were significantly higher in subjects with the CRP + 1444 CT and TT genotypes compared to those with the CRP + 1444 CC genotype (P < 0.5). The percentage of CRP + 1059 C allele was 6.7% (17/252) in the CP group and 4.9% (11/226) in the control group. The percentage of CRP + 1444 T allele was 6.3% (16/252) in the CP group and 5.3% (12/226) in the control group (P > 0.5). There was no significant difference between groups in both allele frequencies (P > 0.5). The association of CRP + 1059G/C, CRP + 1444 C/T polymorphisms with CP was not found in a regression model (P > 0.5). CONCLUSIONS: The presence of a CRP + 1059C-allele was associated with lower serum CRP levels and the presence of a CRP + 1444T-allele was associated with higher serum CRP levels. However, the data suggested that CRP + 1059G/C, CRP + 1444 C/T polymorphisms were not significantly associated with serum CRP levels of chronic periodontitis patients in ethnic Han Chinese.

[Invasion of four common periodontal pathogens into vascular endothelial cells in vitro].

OBJECTIVE: To investigate the adhesive and invasive ability of four common periodontal pathogens, Pg33277, Pi25611, Aa29522 and Fn10953 in human umbilical vein endothelial cells (HUVEC). METHODS: The model of infection of HUVEC by periodontal pathogens was established in vitro. The invasive ability of four periodontal pathogens in HUVEC was tested by scanning electron microscope (SEM) and antibiotic protection assays-colony-forming units (CFU). RESULTS: All of the four periodontal pathogens were found to adhere to HUVEC by SEM and invaded HUVEC at invasion numbers of (0.8 +/- 0.1) x 10(8), (4.1 +/- 0.5) x 10(6), (1.6 +/- 0.3) x 10(6) and (5.0 +/- 0.4) x 10(6) CFU/L respectively by antibiotic protection assays-CFU. The invasion efficiencies were (0.400 +/- 0.050)%, (0.021 +/- 0.003)%, (0.008 +/- 0.002)% and (0.025 +/- 0.002)%, respectively. The invasive ability of Pg33277 was significantly greater than those of the other three periodontal pathogens (P < 0.001). There was no difference in invasive abilities among Pi25611, Aa29522 and Fn10953 (P > 0.05). CONCLUSIONS: All of the four common periodontal pathogens, Pg33277, Pi25611, Aa29522 and Fn10953 could adhere to and invaded HUVEC, with Pg33277 being the strongest.

[Comparative study on the ability of adhesion and invasion of different fimA genetypes of Porphyromonas gingivalis to oral epithelial cells].

OBJECTIVE: To compare the ability of adhesion and invasion to epithelial cells by Porphyromonas gingivalis (Pg) strains with different fimA separated from Chinese. METHODS: Cultured method and antibiotic protection method were used to determine the adhesive and invasive ability of Pg with different fimA genetypes. The adhesion was observed by scanning electron microscope. RESULTS: All the strains adhered and invaded to KB cells, and the adhesion rate ranged from 0.523% to 37.125% and invasive rate from 0.017% to 3.750%.The adhesive and invasive ability among different fimA genotypes showed no significant difference (P > 0.05). CONCLUSIONS: There is no significant correlation between fimA genotype and ability in adhesion and invasion to KB cells.

[Expression of recombinant cytolethal distending toxin of Actinobacillus actinomycetemcomitans].

OBJECTIVE: To examine the expression of recombinant cytolethal distending toxin (CDT) produced by Actinobacillus actinomycetemcomitans (Aa). METHODS: CDT encoding gene cdtABC was amplified by PCR. Through TA clone and restriction endonuclease digestion, gene cdtABC and vector pQE60 were ligated to form pQE60-cdtABC expression system which transformed into competent cells. Protein expression was induced by IPTG and examined by SDS-PAGE and Western-blotting. RESULTS: Random colony PCR of pQE60-cdtABC transformed cells demonstrated that all strains contained cdtABC gene. The DNA sequence was blast with cdtABC gene from GenBank and 99% homology was obtained. SDS-PAGE and Western-blotting confirmed that recombinant CDT was obtained. CONCLUSIONS: CDT protein expression system was reconstructed and recombinant protein was obtained. Actinobacillus actinomycetemcomitans;

[Effects of C-reactive protein on chemotaxis ability of monocytes in vitro].

OBJECTIVE: To investigate the effects of C-reactive protein (CRP) on monocytes chemotaxis ability in vitro. METHODS: Transwell chemotaxis assay was used to evaluate the changes of chemotactic ability of THP-1 monocytes in each group treated with CRP in different concentration. RESULTS: CRP increased the number of attracted monocytes in response to MCP-1 (monocyte chemoattractant protein-1). When treated with CRP concentration at 2 microg x mL(-1), the number of chemotactic monocytes increased (P < 0.05). The number of attracted monocytes increased as CRP concentration was elevated (P < 0.05). CONCLUSION: CRP can increase chemotactic ability of THP-1 monocytes in concentration dependent manner.