Mapping the Scientific Landscape of Bacterial Influence on Oral Cancer: A Bibliometric Analysis of the Last Decade's Medical Progress.

The research domain investigating bacterial factors in the development of oral cancer from January 2013 to December 2022 was examined with a bibliometric analysis. A bibliometric analysis is a mathematical and statistical method used to examine extensive datasets. It assesses the connections between prolific authors, journals, institutions, and countries while also identifying commonly used keywords. A comprehensive search strategy identified 167 relevant articles, revealing a progressive increase in publications and citations over time. China and the United States were the leading countries in research productivity, while Harvard University and the University of Helsinki were prominent affiliations. Prolific authors such as Nezar Al-Hebshi, Tsute Chen, and Yaping Pan were identified. The analysis also highlights the contributions of different journals and identifies the top 10 most cited articles in the field, all of which focus primarily on molecular research. The article of the highest citation explored the role of a Fusobacterium nucleatum surface protein in tumor immune evasion. Other top-cited articles investigated the correlation between the oral bacteriome and cancer using 16S rRNA amplicon sequencing, showing microbial shifts associated with oral cancer development. The functional prediction analysis used by recent studies has further revealed an inflammatory bacteriome associated with carcinogenesis. Furthermore, a keyword analysis reveals four distinct research themes: cancer mechanisms, periodontitis and microbiome, inflammation and Fusobacterium, and risk factors. This analysis provides an objective assessment of the research landscape, offers valuable information, and serves as a resource for researchers to advance knowledge and collaboration in the search for the influence of bacteria on the prevention, diagnosis, and treatment of oral cancer.

Association of Dental Fluorosis and Urinary Fluoride with Intelligence among Schoolchildren.

Fluoride is present naturally in water and has been used worldwide for the prevention of caries. Several studies conducted in high water fluoride or endemic fluorosis areas reported that fluoride adversely affected children's cognitive function, but some studies had negative findings. This study aimed to assess the relationship between urinary fluoride, dental fluorosis, and intelligence among schoolchildren living in communities with non-fluoridated drinking water. This cross-sectional study was conducted on 562 children aged 6-12 years in Taichung, Taiwan. Each child's urinary fluoride level was determined by a fluoride-ion-selective electrode, and the dental fluorosis condition was evaluated according to the criteria of Dean's Index. The Raven's Colored Progressive Matrices-Parallel and Standard Progressive Matrices-Parallel were used to assess children's intelligence. The results showed that the mean (±standard deviation) urinary fluoride concentrations were 0.40 ± 0.27 mg/L (0.43 ± 0.23 mg/g creatinine) among participants. The prevalence of dental fluorosis was 23.67%. After extensive evaluation of potential confounders, dental fluorosis and urinary fluoride were not associated with intelligence quotient (IQ) scores or grades in the regression models. In conclusion, dental fluorosis and urinary fluoride levels were not significantly related to the IQ of schoolchildren living in areas with low drinking water fluoride.

The three-year evolution of overactive bladder syndrome in community-dwelling female residents aged 40 years and above.

OBJECTIVE: In this 3-year longitudinal cohort study, we aimed to evaluate the evolution of overactive bladder in female community residents aged 40 years and above in central Taiwan and identify its risk factors. MATERIALS AND METHODS: Female community residents aged 40 years and above were invited to participate in this study and fill out a yearly Overactive Bladder Symptom Score (OABSS) questionnaire over a 3-year period. A woman was defined to have OAB if the total OABSS was ≧4 and urgency score was ≧2. At the end of the third year, the incidence, remission, persistence, and relapse of OAB in these community residents were calculated. A novel statistical analysis technique, machine learning with data mining, was applied to examine its use in this field. Five machine learning models were used to predict the risk factors associated with persistent OAB and the results were compared with the conventional logistic regression model. RESULTS: In total, 1469 female residents were included in the first year and 1290 (87.8%) women completed the questionnaires for all 3 years. The prevalence of OAB was 20.2% (n = 260). The second- and third-year incidence rates of OAB were 13.5% and 7.1%. The remission rates were 39.6% and 44.3%. Twenty-two percent of the women reported relapse of OAB in the third year. The two-year OAB persistence rate was 43.8%. For the prediction of risk factors for persistent OAB, the multivariable logistic regression model had better predictive accuracy (AUC = 0.664) than the five machine learning models. Age â‰§ 60 was associated with persistent OAB (OR 2.8; 95% CI: 1.34-5.89, P = 0.002). CONCLUSION: The yearly incidence, remission, and persistence rates of OAB were high in female community residents aged 40 years and above in central Taiwan. Older women had a higher risk of persistent OAB symptoms in this 3-year longitudinal cohort study.

Optical properties evaluation of rapid sintered translucent zirconia with two dental colorimeters.

BACKGROUND/PURPOSE: The efficient rapid sintering technique has employed to dental zirconia ceramics for shortening the fabrication time of zirconia restorations. The purpose was to compare the optical properties of two generations of rapid sintered translucent zirconia using two dental colorimeters. MATERIALS AND METHODS: Two generations of translucent zirconia ceramics, 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP): Copran Zr-i Ultra-T (UT) and Cercon HT (HT), and 5 mol% yttria-tetragonal zirconia polycrystal (5Y-TZP): Cercon xt (XT), of different thicknesses (0.5, 0.8, and 1.2 mm; n = 5) underwent rapid sintering (RS) or conventional sintering (CS). The CIELAB values were measured on the white and black backgrounds, respectively, by digital colorimeters, shadepilot, DeguDent (DD) and Easyshade V, Vita (Vita). Translucency parameter (TP), color difference (ΔE), surface morphology, and surface roughness were evaluated. RESULTS: RS resulted in reduced lightness, except in the XT group. The chromaticity increased slightly after RS. Translucency decreased with increasing material thickness. ΔE values differed between both sintering processes but were clinically acceptable (ΔE < 5). Grain size of XT decreased after RS. RS did not affect the surface roughness. CONCLUSION: RS is a feasible method for shortening the manufacturing time of zirconia restorations. A significant difference in TP value was only in the XT group between both sintering methods as measured on DD. Color differences in rapid sintered translucent zirconia materials are imperceptible and acceptable. The specimen thickness affected more in the TP values of Vita than DD. DD has higher sensitivity to translucency and color compared with Vita.

Anthropometric Status, Diet, and Dental Caries among Schoolchildren.

Childhood dental caries and obesity are prevalent health problems. Results from previous studies of the caries-obesity relationship are conflicting. This study aimed to assess the association between anthropometric status and dental caries among schoolchildren, taking into account dietary habits, oral hygiene, and sociodemographic factors. This cross-sectional study recruited 569 children aged 6-12 years from five elementary schools in central Taiwan. Each child underwent an oral health examination and anthropometric measurements. The DMFT (decayed, missing due to caries, and filled permanent teeth) and deft (decayed, extracted, and filled primary teeth) indexes were calculated to record caries experience. A structured questionnaire was used to collect information on food intake frequency and other related factors. The World Health Organization's reference data was applied to define weight status: obese, overweight, and normal/underweight. The results showed that the mean (±standard deviation) deft and DMFT scores were 2.3 ± 2.6 and 0.7 ± 1.2, respectively, among participating children. The prevalence of obesity and overweight was 18.1% and 18.5%, respectively. After comprehensive evaluation of potential confounders, weight status was not an independent predictor of DMFT or deft scores in the negative binomial regression models. In conclusion, weight status was not associated with caries scores in primary or permanent teeth among 6-12 year-old schoolchildren.

A 3-year longitudinal survey of overactive bladder in community-dwelling male residents aged 40 years and above.

OBJECTIVES: To evaluate the short-term evolution and risk factors of overactive bladder (OAB) in community-dwelling male residents aged 40 years and above in central Taiwan. METHODS: This was a 3-year longitudinal cohort study. From January 2012 to December 2012, community residents aged 40 years and above, living in central Taiwan, were invited to participate in this study. A yearly Overactive Bladder Symptom Score (OABSS) questionnaire was used to assess the prevalence, incidence, remission, persistence, and relapse of OAB for three consecutive years. OAB was defined as total OABSS ≧4 and urgency score ≧2. RESULTS: Nine hundred forty-one male residents aged ≧40 years were recruited. The prevalence of OAB was 15%. The male residents with OAB were older, had a history of urological surgery, were unemployed, had lower educational levels, and lower yearly incomes compared with male residents without OAB. The prevalence increased with age when stratified into different age cohorts (40-49, 7%; 50-59, 12.7%; 60-69, 18.2%; ≧70, 32%; P < .001). Age ≧60 (odds ratio [OR] 2.58; 95% CI, 1.62-4.11) and history of urological surgery (OR 2.85; 95% CI, 1.29-6.30) were the major risk factors after multivariable logistic regression analysis. Eight hundred participants completed all the 3 years' questionnaires. The second- and third-year incidence rates of OAB were 10% (69/691) and 6.2% (42/674), respectively. The remission rates were 47.7% (52/109) and 46% (58/126), respectively. The two-year OAB persistence rate was 30.3% (33/109). CONCLUSIONS: The prevalence and yearly incidence of OAB are high in community-dwelling male residents aged ≧40 years in central Taiwan. Age is an important risk factor.

Assessment of relationship between maxillary sinus membrane thickening and the adjacent teeth health by cone-beam computed tomography.

BACKGROUND/PURPOSE: Maxillary posterior teeth have close anatomical proximity to the maxillary sinus floor. The aim of this retrospective study was to evaluate the associations between maxillary sinus membrane thickening and the adjacent teeth health by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images were collected from 235 Taiwanese patients. The sinus mucosal thickening >2 mm is considered a pathologic sinus membrane. Demographic data such as sex, age, the thickness of sinus membrane, and the adjacent teeth health were recorded, graded, and analyzed. RESULTS: A total prevalence of maxillary sinus membrane thickening of 36.6% (86/235) was found in this study. The sinus membrane thickening was significantly associated with periodontal bone loss (p < 0.001) and periapical lesions (p < 0.001), respectively. A multivariate logistic regression model demonstrated that males had a significantly higher risk of sinus membrane thickening than females (OR: 2.08, 95% CI = 1.21-3.56). The patients in the age group ≥60 years showed a 4.35-fold increased risk of sinus membrane thickening compared with the patients in the age group ≤35 years (95% CI: 1.94-9.77). Severe periodontal bone loss was significantly associated with mucosal thickening with an OR of 4.78 as compared with normal to mild group (95% CI: 1.69-13.58). The patients having teeth with apical lesions had a 5.04 time OR for sinus membrane thickening than those having teeth without apical lesions (95% C.I.: 2.37-10.69). CONCLUSION: The prevalence of maxillary sinus membrane thickening was more frequently occurred in male and older people. Periodontal bone loss and periapical lesions were significantly associated with maxillary sinus membrane thickening.

Potential Oral Health Care Agent from Coffee Against Virulence Factor of Periodontitis.

BACKGROUND: Coffee is a major dietary source of polyphenols. Previous research found that coffee had a protective effect on periodontal disease. In this study, we aimed to investigate whether coffee extract and its primary phenolic acid, chlorogenic acid, affect the growth and protease activity of a periodontopathogen Porphyromonas gingivalis (P. gingivalis). METHODS: Coffee extract and chlorogenic acid were prepared by a two-fold serial dilution. The turbid metric test and plate count method were used to examine the inhibitory effects of chlorogenic acid on P. gingivalis. The time-kill assay was used to measure changes in the viability of P. gingivalis after exposure to chlorogenic acid for 0-24 h. The protease activity of P. gingivalis was analyzed using the optical density of a chromogenic substrate. RESULTS: As a result, the minimum inhibitory concentration (MIC) of chlorogenic acid was 4 mg/mL, and the minimum bactericidal concentration was 16 mg/mL. Chlorogenic acid at concentrations above MIC resulted in a longer-lasting inhibitory effect on P. gingivalis viability and significantly reduced associated protease activity. The coffee extract showed antibacterial activity as observed by the disk diffusion test, whereas these inhibitory effects were not affected by different roast degrees of coffee. CONCLUSIONS: Collectively, our novel findings indicate that chlorogenic acid not only has antimicrobial activity but also reduced the protease activity of P. gingivalis. In addition, coffee extract inhibits the proliferation of P. gingivalis, which may partly be attributed to the effect of chlorogenic acid.

A community-based epidemiological survey of overactive bladder and voiding dysfunction in female Taiwanese residents aged 40 years and above.

OBJECTIVE: This is part of a three-year study designed to evaluate the natural history of lower urinary tract symptoms in local community residents aged 40 years and above in central Taiwan. We evaluated the prevalence of overactive bladder (OAB) and voiding dysfunction (VD) in female residents using validated questionnaires. MATERIALS AND METHODS: A structured questionnaire containing groups of different questionnaires was translated into Chinese and each one was validated separately. A trained research assistant interviewed the participants and assisted in filling in the questionnaires. Residents were recorded to have OAB if the total OABSS score was≧4. Urge urinary incontinence (UUI) was defined as urine leakage preceded by the feeling of urgency which is slightly or more distressful. VD was defined as feeling of difficulty in emptying the bladder which is slightly or more distressful. RESULTS: A total of 2411 community residents aged 40 years and above who completed all the questionnaires in the initial survey were recruited, of which 1469(60.9%) were women. The prevalence of OAB, UUI and VD were 33.1%, 26.8% and 28.3% respectively in the female community residents. Age≧60 (OR, 1.5; 95%CI, 1.1-2.0), menopause (OR1.4; 95% CI, 1.0-1.9) and a history of diabetes mellitus (OR, 1.8; 95% CI, 1.2-2.8) were the risk factors for OAB. Age≧60 (OR, 1.4; 95%CI, 1.0-1.9), BMI ≧25 (OR, 1.3; 95% CI, 1.0-1.7) and instrument deliveries (OR, 1.5; 95% CI, 1.0-2.1) were the risk factors for VD. CONCLUSION: Our results imply that the prevalence of overactive bladder and voiding difficulty are high in female community residents aged ≧ 40 years in central Taiwan.

Genetic polymorphisms in APE1 Asp148Glu(rs3136820) as a modifier of the background levels of abasic sites in human leukocytes derived from breast cancer patients and controls.

BACKGROUND: Apurinic/apyrimidinic (abasic/AP) sites are among the most common endogenous DNA lesions. AP sites, if not repaired, could result in genomic instability as well as chromosome aberrations. Information regarding the direct assay of the number of abasic sites in human leukocytes and its association with risk of breast cancer has not been reported. METHODS: In this study, we investigated the association between certain risk factors for breast cancer and the background levels of AP sites in leukocytes derived from 148 Taiwanese women with breast cancer and 140 cancer-free controls. The risk factors studied include age, body mass index (BMI), and polymorphisms of apurinic/apyrimidinic endonuclease (APE1) [APE1 Asp148Glu(rs3136820)]. RESULTS: Mean levels of AP sites were estimated to be 23.3 and 50.3 per 106 nucleotides in controls and breast cancer patients, respectively (~twofold, p < 0.001). In subjects with age <50 or BMI < 27 (kg/m2), the levels of AP sites in breast cancer patients were ~2-3-fold greater than those of controls (p < 0.05). Additionally, results from the AP site 3'-cleavage assay indicated that the AP sites detected in both controls and patients were likely to be oxidant-mediated 5'-cleaved AP sites (~61-64 %). The number of AP sites in breast cancer patients was ~twofold greater in subjects with Asp/Glu + Glu/Glugenotypes than those with Asp/Asp genotype (p < 0.001). CONCLUSIONS: We confirmed that cumulative body burden of AP sites is a significant predictor of the risk of developing breast cancer and that genetic predisposition and environment factors may modulate the induction of oxidative DNA lesions in breast cancer patients.

Impact Behavior of Three Notched All-Ceramic Restorations after Soaking in Artificial Saliva.

Biomechanics play a critical role in influencing the clinical applications of all-ceramic dental restorations. The restorative biomaterials have to demonstrate mechanical durability in the oral environment because they are always exposed to a variety of oral environments. This study was designed to evaluate the effect of soaking time, notch and saliva pH values on the impact energy of three commonly used all-ceramic materials for CAD/CAM. The leucite-reinforced glass ceramic (ProCAD), lithium disilicate glass ceramic (IPS e.max CAD) and zirconia-based ceramic materials (IPS e.max ZirCAD) were used. The experimental results indicated that the impact energy of ProCAD decreased with an increase in soaking time, but not for IPS e.max CAD and IPS e.max ZirCAD. The impact energy of the zirconia system was higher than leucite-reinforced and lithium disilicate-based ceramic systems. When subjected to preformed 0.5 mm U-shape notch on the bar specimen of 3 mm thick, the impact energy of the all-ceramic restorations revealed a markedly reduction of about 80%-90%, almost irrespective of dental compositions, which indicated the effect of flaw to a great degree. No statistically significant influence (p > 0.05) of pH values (4, 7 and 9) on impact energy was found for each group. It is concluded that the no matter which all-ceramic materials were used, it was appreciably sensitive to the presence of notches. The ceramic composition and microstructure have been shown to affect mechanical durability.

Antimicrobial activity of platelet-rich plasma and other plasma preparations against periodontal pathogens.

BACKGROUND: In addition to releasing a pool of growth factors during activation, platelets have many features that indicate their role in the anti-infective host defense. The antimicrobial activities of platelet-rich plasma (PRP) and related plasma preparations against periodontal disease-associated bacteria were evaluated. METHODS: Four distinct plasma fractions were extracted in the formulation used commonly in dentistry and were tested for their antibacterial properties against three periodontal bacteria: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. The minimum inhibitory concentration of each plasma preparation was determined, and in vitro time-kill assays were used to detect their abilities to inhibit bacterial growth. Bacterial adhesion interference and the susceptibility of bacterial adherence by these plasma preparations were also conducted. RESULTS: All plasma preparations can inhibit bacterial growth, with PRP showing the superior activity. Bacterial growth inhibition by PRP occurred in the first 24 hours after application in the time-kill assay. PRP interfered with P. gingivalis and A. actinomycetemcomitans attachment and enhanced exfoliation of attached P. gingivalis but had no influences on F. nucleatum bacterial adherence. CONCLUSIONS: PRP expressed antibacterial properties, which may be attributed to platelets possessing additional antimicrobial molecules. The application of PRP on periodontal surgical sites is advisable because of its regenerative potential and its antibacterial effects.

Association of dietary calcium, phosphorus, and magnesium intake with caries status among schoolchildren.

The aim of this study was to investigate the associations between caries experience and daily intake of calcium (Ca), phosphorus (P), magnesium (Mg), and Ca/P ratio. A total of 2248 schoolchildren were recruited based on a population-based survey. Each participant received a dental examination and questionnaire interviews about the 24-hour dietary recalls and food frequency. The daily intake of Ca, P, Mg, and Ca/P ratio were inversely associated with primary caries index, but only the Ca/P ratio remained significant after adjusting for potential confounders. According to the Taiwanese Dietary Reference Intakes, the Ca/P ratio was related to both caries in primary teeth (odds ratio = 0.52, p = 0.02) and in permanent teeth (odds ratio = 0.59, p = 0.02). The daily intakes of Ca/P ratio remained an important factor for caries after considering potential confounding factors.

Hemoglobin adducts as biomarkers of estrogen homeostasis: elevation of estrogenquinones as a risk factor for developing breast cancer in Taiwanese women.

The aim of this study was to establish a methodology to analyze estrogen quinone-derived adducts, including 17ß-estradiol-2,3-quinone (E2-2,3-Q) and 17ß-estradiol-3,4-quinone (E2-3,4-Q), in human hemoglobin (Hb). The methodology was then used to measure the levels of these adducts in Hb derived from female breast cancer patients (n=143) as well as controls (n=147) in Taiwan. Our result confirmed that both E2-2,3-Q- and E2-3,4-Q-derived adducts, including E2-2,3-Q-4-S-Hb and E2-3,4-Q-2-S-Hb, were detected in all breast cancer patients with median levels at 434 (215-1472) and 913 (559-2384) (pmol/g), respectively. Levels of E2-2,3-Q-4-S-Hb correlated significantly with those of E2-3,4-Q-2-S-Hb (r=0.622-0.628, p<0.001). By contrast, median levels of these same estrogen quinone-derived adducts in healthy controls were 71.8 (35.7-292) and 139 (69.1-453) (pmol/g). This translated to ~6-fold increase in mean values of E2-2,3-Q-4-S-Hb and E2-3,4-Q-2-S-Hb in breast cancer patients compared to those in the controls (p<0.001). Our findings add further support to the theme that cumulative body burden of estrogen quinones is an important indicator of breast cancer risk. We hypothesize that combination of genetic events and environmental factors may modulate estrogen homeostasis and enhance the production of estrogen quinones which lead to subsequent generation of pro-mutagenic DNA lesions in breast cancer patients.

Urinary levels of 1-hydroxypyrene in children residing near a coal-fired power plant.

BACKGROUND: The effects of emissions from coal-fired power plants on children's exposure to polycyclic aromatic hydrocarbons (PAHs) are not well understood. OBJECTIVES: This study aimed to evaluate the sources and the urinary levels of 1-hydroxypyrene, a biomarker of exposure to PAHs, among children living in proximity to a coal-fired power plant. METHODS: Study areas consisted of two high exposure and two low exposure communities, at different distances and directions from a large coal-fired power plant in central Taiwan. Study subjects included 369 children aged 1-13 years and randomly selected from each community. Each child's urinary 1-hydroxypyrene concentration was measured by a high-performance liquid chromatography-fluorescence detector method. Samples of ambient air were analyzed for PAHs using a gas chromatography-mass spectrometry method. Information on important factors was collected by an interview using a structured questionnaire. Multiple regression analysis was used to assess factors significantly associated with urinary 1-hydroxypyrene levels. RESULTS: Levels of PAHs in ambient air in the high exposure communities were higher than those in the low exposure communities. Children living in high exposure communities had higher mean urinary 1-hydroxypyrene concentrations than those in low exposure communities (0.186 and 0.194 vs. 0.113 and 0.122 µmol/mol-creatinine, respectively). The difference in urinary 1-hydroxypyrene levels between the high exposure communities and one low exposure community remained significant after adjusting for age, gender, environmental tobacco smoke, dietary exposure, and traffic. CONCLUSIONS: Children living in communities downwind of and in proximity to the coal-fired power plant had significantly increased urinary 1-hydroxypyrene levels.

Relationship between dietary intake and dental caries in preschool children.

This study assessed the relationship between intake of nutrients and dental caries in preschool children. One hundred and eighty-two children aged three to six years were recruited from nine day care centers in central Taiwan. These children had an oral health examination, and their parents or guardians answered a questionnaire. Each child's intake of nutrients was estimated using the 24-hour dietary recall and food frequency questionnaire data. Logistic regression analysis was applied to assess the associations between dental caries and intake of each nutrient or food group, with adjustment for potential confounders. The prevalence of dental caries was 73 % and increased with age. Not being a first-born and having more between-meal snacks were associated with increased caries risk. After controlling for other important factors, vitamin A intake was significantly associated with fewer dental caries (deft, decayed, indicated for extraction, and filled primary teeth: ≥ 4 vs. < 4), with an odds ratio of 0.97 (95 % confidence interval: 0.94 - 0.99) for an 100-µg increase in vitamin A intake. There was no significant association between dental caries and energy, macronutrient intake, and Ca/P ratio, respectively. Vegetable intake was also significantly associated with lower dental caries score.

Association of cytochrome P450 1B1 gene expression in peripheral leukocytes with blood lipid levels in waste incinerator workers.

PURPOSE: This study investigated whether CYP1B1 gene expression was associated with blood lipids levels. METHODS: Workers from a municipal waste incineration plant in Taiwan participated in a questionnaire survey and physical examination and provided fasting blood samples for blood lipid analysis. CYP1B1 gene expression in workers' leukocytes was determined with the real-time reverse transcriptase polymerase chain reaction method, and 112 workers were categorized into three groups (low-, medium-, and high-expression) by their relative CYP1B1 gene expression levels. Multiple regression analyses were used to assess the association between blood lipid parameter and CYP1B1 expression. RESULTS: High-density lipoprotein (HDL) cholesterol was significantly lower in the high CYP1B1 expression group than in the low- and medium-expression groups (parameter estimate [standard error]=-7.16 [2.42] and -7.02 [2.46] mg/dL, respectively), after controlling for age, sex, CYP1B1 genotype, duration of employment, current number of cigarettes smoked per day, current alcohol drinking status, and body mass index. Triglycerides, low-density lipoprotein (LDL), and total cholesterol were not significantly different among the CYP1B1 expression groups. Furthermore, workers carrying the CYP1B1 *3 allele had significantly higher mean HDL, LDL, and total cholesterol, respectively, than those with CYP1B1 *1/ *1. CONCLUSIONS: CYP1B1 expression was associated with decreased HDL cholesterol levels in incinerator workers.

Fracture resistance of Nd:YAG laser-welded cast titanium joints with various clinical thicknesses and welding pulse energies.

The purpose of this study was to evaluate the fracture resistance of Nd:YAG laser-welded cast titanium (Ti) joints with various clinical thicknesses and welding pulse energies. A four-point bending test was used to assess the effects of various specimen thicknesses (1-3 mm) and welding pulse energies (11-24 J) on the fracture resistance of Nd:YAG laser-welded Ti dental joints. Fracture resistance was evaluated in terms of the ratio of the number of fractured specimens to the number of tested specimens. As for the fracture frequencies, they were compared using the Cochran-Mantel-Haenszel test. Morphology of the fractured Ti joints was observed using a scanning electron microscope. Results showed that decreasing the specimen thickness and/or increasing the welding pulse energy, i.e., increasing the welded area percentage, resulted in an increase in the fracture resistance of the Ti joint. Where fracture occurred, the fracture site would be at the center of the weld metal.

Epidemiology of hepatitis B virus infection among young adults in Taiwan, China after public vaccination program.

BACKGROUND: The public vaccination program of hepatitis B virus (HBV) was launched during 1984 in Taiwan, China. However, the long-lasting protective efficacy of HBV vaccination among adolescents older than 15 years of age was seldom recorded. METHODS: A seroepidemiological survey was conducted among 4575 first-year university students in Taiwan, China during 2000 to 2003, including the serological data of HBV by testing HBV surface antigen (HBsAg), surface antibody (anti-HBs), HBV core antibody (anti-HBc) and demographic information. RESULTS: HBsAg carrier rate among male university students born before the initiation of the HBV vaccination program decreased from 12.8% to 4.8% among those born after the vaccination program (P < 0.001, chi(2) test for linear trend). Similarly, HBsAg carrier rate among female university students born before the initiation of the HBV vaccination program decreased from 8.1% to 2.7% among those born after the vaccination program (P < 0.001, chi(2) test for linear trend). Both male and female students in eastern Taiwan had the highest HBsAg carrier rate compared with the other places. Using multiple logistic regression analysis, compared with students born after July 1984, the adjusted OR of HBsAg carrier rate decreased from 3.10 for students born before June 1981 to 1.56 for students born from July 1983 to June 1984 (95% CI 1.96 - 4.91, P < 0.001; 95% CI 1.06 - 2.28, P = 0.024; respectively). CONCLUSIONS: Public vaccination provides long-lasting protection again HBV infection among the university students in Taiwan, China older than 18 years of age. There is a geographic variation of HBV infection among young adults in Taiwan, China.