OBJECTIVETo study the role of fibrinogen molecule in the pathogenesis of periodontal diseases.

METHODSAn 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.

RESULTSThe 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.

CONCLUSIONSFibrinogen promotes the adherence of Pg to human oral epithelial cells and may play an important role in the pathogenesis of periodontal diseases.

Bacterial Adhesion ; drug effects ; Fibrinogen ; administration & dosage ; pharmacology ; Humans ; KB Cells ; Mouth Mucosa ; drug effects ; microbiology ; Periodontitis ; etiology ; Porphyromonas gingivalis ; pathogenicity

OBJECTIVETo project the future impacts of climate change on heat-related mortality in shanghai.

METHODSThe statistical downscaling techniques were applied to simulate the daily mean temperatures of Shanghai in the middle and farther future under the changing climate. Based on the published exposure-reaction relationship of temperature and mortality in Shanghai, we projected the heat-related mortality in the middle and farther future under the circumstance of high speed increase of carbon e mission (A2) and low speed increase of carbon emission (B2). The data of 1961 to 1990 was used to establish the model, and the data of 1991 - 2001 was used to testify the model, and then the daily mean temperature from 2030 to 2059 and from 2070 to 2099 were simulated and the heat-related mortality was projected. The data resources were from U.S. National Climatic Data Center (NCDC), U.S. National Centers for Environmental Prediction Reanalysis Data in SDSM Website and UK Hadley Centre Coupled Model Data in SDSM Website.

RESULTSThe explained variance and the standard error of the established model was separately 98.1% and 1.24°C. The R(2) value of the simulated trend line equaled to 0.978 in Shanghai, as testified by the model. Therefore, the temperature prediction model simulated daily mean temperatures well. Under A2 scenario, the daily mean temperature in 2030 - 2059 and 2070 - 2099 were projected to be 17.9°C and 20.4°C, respectively, increasing by 1.1°C and 3.6°C when compared to baseline period (16.8°C). Under B2 scenario, the daily mean temperature in 2030 - 2059 and 2070 - 2099 were projected to be 17.8°C and 19.1°C, respectively, increasing by 1.0°C and 2.3°C when compared to baseline period (16.8°C). Under A2 scenario, annual average heat-related mortality were projected to be 516 cases and 1191 cases in 2030 - 2059 and 2070 - 2099, respectively, increasing 53.6% and 254.5% when compared with baseline period (336 cases). Under B2 scenario, annual average heat-related mortality were projected to be 498 cases and 832 cases in 2030 - 2059 and 2070 - 2099, respectively, increasing 48.2% and 147.6% when compared with baseline period (336 cases).

CONCLUSIONUnder the changing climate, heat-related mortality is projected to increase in the future;and the increase will be more obvious in year 2070 - 2099 than in year 2030 - 2059.

China ; Climate Change ; Greenhouse Effect ; Humans ; Models, Theoretical ; Mortality ; Risk Assessment

OBJECTIVETo 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).

METHODSA 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.

RESULTSFibrinogen 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).

CONCLUSIONSFg-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.

Adult ; Alleles ; Case-Control Studies ; Chronic Periodontitis ; genetics ; Coronary Disease ; genetics ; Female ; Fibrinogen ; analysis ; genetics ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length

Adult ; Female ; Hepatitis B Core Antigens ; analysis ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B virus ; isolation & purification ; Hepatitis B, Chronic ; virology ; Humans ; Ovary ; virology

OBJECTIVETo investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC).

METHODSNano-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.

RESULTSThere 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.

CONCLUSIONSThe nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.

Alkaline Phosphatase ; metabolism ; Cell Differentiation ; drug effects ; Cells, Cultured ; Durapatite ; administration & dosage ; pharmacology ; Humans ; Periodontal Ligament ; cytology ; enzymology

OBJECTIVEThe 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.

METHODSP. 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.

RESULTSIL-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.

CONCLUSIONfimA genotypes of P. gingivalis are related with the effect of IL-8 inductions, which indicates fimA genotype is associated with pathogenesis of P. gingivalis.

Cells, Cultured ; Coculture Techniques ; Epithelial Cells ; Genotype ; Humans ; Interleukin-6 ; Interleukin-8 ; Porphyromonas gingivalis

OBJECTIVETo 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.

METHODS95 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.

RESULTSFibrinogen 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.

CONCLUSIONModerately 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.

Chronic Periodontitis ; Coronary Disease ; Female ; Humans ; Male ; Middle Aged ; Periodontal Index ; Periodontitis ; Risk Factors

0.05).In group Ⅱand Ⅲ,the carotid artery IMT was thicker and the amount of plagues were larger than those in group Ⅰ(P

The regeneration capacity of cardiomyocytes (CMs) is retained in neonatal mouse hearts but is limited in adult mouse hearts. Myocardial infarction (MI) in adult hearts usually leads to the loss of large amounts of cardiac tissue, and then accelerates the process of cardiac remodeling and heart failure. Therefore, it is necessary to explore the potential mechanisms of CM regeneration in the neonates and develop potential therapies aimed at promoting CM regeneration and cardiac repair in adults. Currently, studies indicate that a number of mechanisms are involved in neonatal endogenous myocardial regeneration, including cell cycle regulators, transcription factors, non-coding RNA, signaling pathways, acute inflammation, hypoxia, protein kinases, and others. Understanding the mechanisms of regeneration in neonatal CMs after MI provides theoretical support for the studies related to the promotion of heart repair after MI in adult mammals. However, several difficulties in the study of CM regeneration still need to be overcome. This article reviews the potential mechanisms of endogenous CM regeneration in neonatal mouse hearts and discusses possible therapeutic targets and future research directions.

Objective To investigate the effect of one of the acute-phase proteins,fibrinogen,on the release of IL-1β 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 balaneed saline solution(1×109/L)supplemented with 0.5% BSA and 0.1% glucose.The levels of I-1β 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-1β [(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 offibrinogen(IL-1β,P＜0.001,and IL-8,P≤0.016).The higher concentration of fibrinogen or the longer treatment time,the higher levels of IL-1β and -8 were released by PMN(P＜0.001).Conclusions Fibrinogen induced the secretion of pro-inflammatory cytokines IL-1β and-8 by PMN and may be involved in magnification of the inflammatory response of periodontium and bone resorption.