Risk for Donor-Derived Syphilis after Kidney Transplantation, China, 2007-2022.

To evaluate the risk of acquiring syphilis from a donated kidney, we evaluated kidney transplantation pairs from West China Hospital, Sichuan, China, during 2007-2022. Donor-derived syphilis was rare. Risk may be higher if donors have active syphilis and may be reduced if recipients receive ceftriaxone.

Was antiviral prophylaxis necessary after kidney transplantation utilizing HBcAb+ donors? A systematic review and meta-analysis.

BACKGROUND: Current guidelines lack consensus on whether antiviral prophylaxes should be administered after kidney transplantation from HBcAb+ donors. This systematic review and meta-analysis aimed to evaluate the incidence and risk factors of de novo HBV (DNH) infection, as well as graft and patient survival. METHODS: We searched PubMed, Embase, and the Cochrane Library up to December 31, 2023. We included relevant studies that assessed clinical outcomes following transplantation utilizing HBcAb+ kidneys. Summary measures of effect and 95% confidence intervals (CI) for prevalence, risk factors, as well as graft and patient survival were estimated using random-effects meta-analysis. RESULTS: Thirteen studies were included for the final analysis. The DNH incidence was at 0.36% (9/2516) with low heterogeneity (I2 = 6%). HBsAb+ recipients (OR: 0.78, 95%CI: 0.25-2.38), HBcAb+ recipients (OR: 3.11, 95%CI: 0.91-10.66, P = 0.071), and recipients not receiving any antiviral prophylaxis (OR: 1.26, 95%CI: 0.15-10.58) were not associated with higher DNH risk. Specifically, HBsAb-/HBcAb+ recipients had the highest DNH incidence (4.65%), followed by HBsAb-/HBcAb- (0.49%), HBsAb+/HBcAb- recipients (0.45%), and HBsAb+/HBcAb+ (0%). Furthermore, recipients receiving HBcAb+ kidneys had comparable graft survival (HR: 1.06, 95%CI: 0.94-1.19, P = 0.55) and patient survival (HR:1.16, 95%CI: 0.98-1.38, P = 0.090) compared with recipients receiving HBcAb- kidneys. CONCLUSION: Kidney transplantation utilizing HBcAb+ kidneys contributed to comparable graft and patient survival with an extremely low risk of HBV transmission. Antiviral prophylaxes may only be administered in HBsAb-/HBcAb+ recipients.

Expanding the donor pool: Kidney transplantation from serum HBV DNA or HBeAg-positive donors to HBsAg-negative recipients.

BACKGROUND & AIMS: HBsAg-positive (HBsAg[+]) donors are rarely accepted for kidney transplantation (KT), especially when the donor is also HBV DNA-positive (HBV DNA[+]) or HBeAg-positive (HBeAg[+]) serologically. This study aimed to report kidney transplant outcomes from HBsAg(+) donors to HBsAg(-) recipients. METHODS: Consecutive cases were retrospectively identified from 1 July 2017 to 31 December 2020. KTs from HBsAg(-)/HBcAb-positive (HBcAb[+]) donors to HBcAb(-) recipients were selected as the control group. The primary outcomes were de novo HBV infection (DNH), graft and patient survival. RESULTS: We identified 105 HBsAg(-) recipients who received HBsAg(+) kidneys and 516 HBcAb(-) recipients who received HBcAb(+) kidneys. A higher DNH rate was observed after receiving HBsAg(+) kidneys than after receiving HBcAb(+) kidneys after a median follow-up of 23.0 months (4/105[3.8%] vs. 2/516[0.4%], p = .009). All four infected recipients receiving HBsAg(+) kidneys had HBsAg clearance after treatment. Graft and patient survival were comparable between the groups (p = .630, p = .910). The DNH rates were 0/22(0%), 3/70(4.3%) and 1/13(7.7%) after receiving HBsAg(+), HBV DNA(+) and HBeAg(+) kidneys, respectively (p = .455). The DNH rate was lower if the donor had received antiviral treatment (4/42[9.5%] vs. 0/63[0%], p = .023). HBsAb(-) recipients had a higher DNH incidence than HBsAb(+) recipients (3/25[12.0%] vs. 1/80[1.3%], p = .041). CONCLUSIONS: The use of HBsAg(+) donors contributed to comparable graft and patient survival, but HBV DNA(+) or HBeAg(+) donors and HBsAb(-) recipients maybe associated with a higher risk of HBV infection. These findings help expand the donor pool and emphasize the role of donor antiviral treatment and recipient HBV immunity in establishing optimal prophylactic regimens.

Treatment of donors' asymptomatic small kidney stones and post-transplant outcomes: a meta-analysis.

Kidney donors with asymptomatic small kidney stones were increasingly accepted in kidney transplantation (KT) due to organ shortage and advances in endoscopic urology. However, recipients' clinical outcomes using these donors remained unclear. We conducted a meta-analysis to summarize transplant outcomes using these donors with asymptomatic small kidney stones. Finally, 15 retrospective studies were included. The prevalence of asymptomatic small kidney stones was 5.3% (95%CI 3.5-7.8%). After transplantation, low incidence of urinary fistula (0%, 95%CI 0-1.0%), obstruction (0%, 95%CI 0-1.1%), relapse of kidney graft stone (0.3%, 95%CI 0-2.5%), and delayed graft function (0.6%, 95%CI 0-3.5%) was reported. Pooled serum creatinine was 1.3 (95%CI 1.2-1.5) mg/dl and 1.4 (95%CI 1.2-1.6) mg/dl at post-transplant 1 month and 1 year, respectively. Notably, we observed numerically higher relapse rate after conservative management (1.8% [0-9.2%] vs 0% [0-1.8%]) but numerically higher DGF rate after surgical removal of asymptomatic stones (1.8% [0-7.0%] vs 0% [0-1.9%]). Overall, short-term transplant outcomes using kidneys with asymptomatic small stones were acceptable. However, long-term transplant outcomes remained unexplored. Well-designed prospective studies are also needed to compare the efficacy of conservative management with surgical removal of "donors' gifted" asymptomatic kidney stones.

Psoriasis and risk of chronic kidney diseases: A population-based cross-sectional study and Mendelian randomization analysis.

BACKGROUND: Conflicting results have been reported regarding the association between psoriasis and risk of chronic kidney diseases (CKD). Furthermore, the causal nature of the possible association remains unexplored. METHODS: We conducted a population-based cross-sectional study using data from National Health and Nutrition Examination Survey (NHANES). Logistic regression analyses were conducted to estimate potential association between psoriasis and CKD risk. Further, we evaluated causality by performing a Mendelian randomization analysis using large-scale genome-wide association studies of psoriasis and CKD. Inverse variance-weighted (IVW) analysis was used as the primary method. RESULTS: In the observational study, 16 750 participants were included. Overall, 39 of 429 patients with psoriasis had CKD (9.1%) compared with 1481 of 16 321 without psoriasis (9.1%). In the fully adjusted model, psoriasis was not associated with CKD (OR: 0.77, 95%CI: 0.53-1.10). In the MR analysis, 36 single-nucleotide polymorphisms (SNPs) were selected as instrumental variables. The IVW analysis reported that genetically predicted psoriasis was associated with a higher risk of CKD (OR: 1.025, 95%CI: 1.001-1.049). After removing 2 SNPs associated with heterogeneity, the association remained (OR: 1.028, 95%CI: 1.006-1.050). CONCLUSION: Genetically predicted psoriasis was associated with a higher risk of CKD. This association may be important for clinicians to monitor kidney function and prescribe potentially nephrotoxic drugs during psoriasis management.

Incidence, risk factors, and clinical outcomes of HBV reactivation in non-liver solid organ transplant recipients with resolved HBV infection: A systematic review and meta-analysis.

BACKGROUND: Current guidelines do not recommend routine antiviral prophylaxis to prevent hepatitis B virus (HBV) reactivation in non-liver solid organ transplant (SOT) recipients with resolved HBV infection, even in anti-hepatitis B surface antigen (anti-HBs)-negative recipients and those receiving intense immunosuppression. This systematic review and meta-analysis aimed to determine the incidence, risk factors, and clinical outcomes of HBV reactivation in non-liver SOT recipients. METHODS AND FINDINGS: Three databases (PubMed, Embase, and Cochrane Library) were systematically searched up to December 31, 2022. Clinical studies reporting HBV reactivation in non-liver SOT recipients were included. Case reports, case series, and cohort studies with a sample size of less than 10 patients were excluded. Random-effects analysis was used for all meta-analyses. We included 2,913 non-liver SOT recipients with resolved HBV infection from 16 retrospective cohort studies in the analysis. The overall HBV reactivation rate was 2.5% (76/2,913; 95% confidence interval [95% CI 1.6%, 3.6%]; I2 = 55.0%). Higher rates of reactivation were observed in recipients with negative anti-HBs (34/421; 7.8%; 95% CI [5.2%, 10.9%]; I2 = 36.0%) by pooling 6 studies, experiencing acute rejection (13/266; 5.8%; 95% CI [2.3%, 14.5%]; I2 = 63.2%) by pooling 3 studies, receiving ABO blood type-incompatible transplantation (8/111; 7.0%; 95% CI [2.9%, 12.7%]; I2 = 0%) by pooling 3 studies, receiving rituximab (10/133; 7.3%; 95% CI [3.4%, 12.6%]; I2 = 0%) by pooling 3 studies, and receiving anti-thymocyte immunoglobulin (ATG, 25/504; 4.9%; 95% CI [2.5%, 8.1%]; I2 = 49.0%) by pooling 4 studies. Among recipients with post-transplant HBV reactivation, 11.0% (7/52; 95% CI [4.0%, 20.8%]; I2 = 0.3%) developed HBV-related hepatic failure, and 11.0% (7/52; 95% CI [4.0%, 20.8%]; I2 = 0.3%) had HBV-related death. Negative anti-HBs (crude odds ratio [OR] 5.05; 95% CI [2.83, 9.00]; p < 0.001; I2 = 0%), ABO blood type-incompatible transplantation (crude OR 2.62; 95% CI [1.05, 6.04]; p = 0.040; I2 = 0%), history of acute rejection (crude OR 2.37; 95% CI [1.13, 4.97]; p = 0.022; I2 = 0%), ATG use (crude OR 3.19; 95% CI [1.48, 6.87]; p = 0.003; I2 = 0%), and rituximab use (crude OR 3.16; 95% CI [1.24, 8.06]; p = 0.016; I2 = 0%) increased the risk of reactivation. Adjusted analyses reported similar results. Limitations include moderate heterogeneity in the meta-analyses and that most studies were conducted in kidney transplant recipients. CONCLUSIONS: Non-liver SOT recipients with resolved HBV infection have a high risk of HBV-related hepatic failure and HBV-related death if HBV reactivation occurs. Potential risk factors for HBV reactivation include rituximab use, anti-thymocyte immunoglobulin use, anti-HBs negative status, acute rejection history, and ABO blood type-incompatible transplantation. Further research on monitoring and routine antiviral prophylaxis of non-liver SOT recipients at higher risk of HBV reactivation is required.

Integrated Analysis of Energy Metabolism Signature-Identified Distinct Subtypes of Bladder Urothelial Carcinoma.

Background: Bladder urothelial carcinoma (BLCA) is the most common type of bladder cancer. In this study, the correlation between the metabolic status and the outcome of patients with BLCA was evaluated using data from the Cancer Genome Atlas and Gene Expression Omnibus datasets. Methods: The clinical and transcriptomic data of patients with BLCA were downloaded from the Cancer Genome Atlas and cBioPortal datasets, and energy metabolism-related gene sets were obtained from the Molecular Signature Database. A consensus clustering algorithm was then conducted to classify the patients into two clusters. Tumor prognosis, clinicopathological features, mutations, functional analysis, ferroptosis status analysis, immune infiltration, immune checkpoint-related gene expression level, chemotherapy resistance, and tumor stem cells were analyzed between clusters. An energy metabolism-related signature was further developed and verified using data from cBioPortal datasets. Results: Two clusters (C1 and C2) were identified using a consensus clustering algorithm based on an energy metabolism-related signature. The patients with subtype C1 had more metabolism-related pathways, different ferroptosis status, higher cancer stem cell scores, higher chemotherapy resistance, and better prognosis. Subtype C2 was characterized by an increased number of advanced BLCA cases and immune-related pathways. Higher immune and stromal scores were also observed for the C2 subtype. A signature containing 16 energy metabolism-related genes was then identified, which can accurately predict the prognosis of patients with BLCA. Conclusion: We found that the energy metabolism-associated subtypes of BLCA are closely related to the immune microenvironment, immune checkpoint-related gene expression, ferroptosis status, CSCs, chemotherapy resistance, prognosis, and progression of BLCA patients. The established energy metabolism-related gene signature was able to predict survival in patients with BLCA.

Effect of Donor and Recipient ABH-Secretor Status on ABO-Incompatible Living Donor Kidney Transplantation.

Introduction: ABO blood group antigens within grafts are continuously exposed to anti-A/B antibodies in the serum of recipients after ABO-incompatible (ABOi) kidney transplantation and are instrumental in antibody-mediated rejection. Some individuals secrete soluble blood group antigens into body fluids. In this study, we investigated the effect of donor and recipient secretor status on the outcomes of ABOi kidney transplantation. Methods: Data of a total of 32 patients with ABOi living donor kidney transplantation were retrospectively collected between 2014 and 2020 in West China Hospital. The genotype and phenotype of both donors and recipients were examined and evaluated with post-transplantation anti-A/B titer changes, graft function, and rejection. Results: Of the 32 recipients and 32 donors, 23 (71.9%) recipients and 27 (84.4%) donors had secretor genotypes, whereas 9 (28.1%) recipients and 5 (15.6%) donors did not. Anti-A/B titers after ABOi kidney transplantation were not significantly influenced by the secretor status of either donors or recipients. The post-transplantation serum creatinine (Scr) levels and estimated glomerular filtration rate (eGFR) was better in weak- or non-secretor recipients at day 30 (Scr P = 0.047, eGFR P = 0.008), day 90 (Scr P = 0.010, eGFR P = 0.005), and month 9 (eGFR P = 0.008), and recipients from secretor donors had a lower incidence of graft rejection in the first year after ABOi transplantation (P = 0.004). Conclusions: A weak secretor status phenotype was found in both genotypes, i.e., individuals who secreted soluble antigens as well as those who did not. The recipient ABH-secretor status may have an influence on early posttransplant renal function, and the donor ABH-secretor status might affect the incidence of graft rejection.

Does inflammatory bowel disease increase the risk of lower urinary tract tumors: a meta-analysis.

BACKGROUND: Inflammatory bowel disease, including ulcerative colitis and Crohn's disease, is characterized by chronic inflammation that could be a risk factor for extraintestinal cancer. The aim of this study is to evaluate whether inflammatory bowel disease is related to the risk of lower urinary tract tumors. METHODS: A systematical research was performed on various medical databases including PubMed, the Cochrane Library, Embase and Web of Science from inception to April 2020. Data were independently extracted by two reviewers. The Newcastle-Ottawa Scale and the Oxford Centre for Evidence-Based Medicine criteria were used to assess the quality of included articles. The analysis was completed by STATA version 14.2. RESULTS: Six hundred and twelve of records were initially identified and 16 studies were included in the final analysis. In general, inflammatory bowel disease patients were not at increased risk of prostate cancer, bladder cancer and male genital cancer. In the subgroup analysis, Crohn's disease patients seemed to have borderline increased risk of prostate cancer [standardized incidence ratio: 1.05; 95% confidence interval (CI): 0.90-1.21; I2=15.1%] and bladder cancer (standardized incidence ratio: 1.19; 95% CI: 0.94-1.44; I2=0.0%), and ulcerative colitis patients seemed to have borderline increased risk of prostate cancer (standardized incidence ratio: 1.13; 95% CI: 0.93-1.33; I2=73.5%). CONCLUSIONS: Inflammatory bowel disease did not significantly increase the risk of prostate cancer, bladder cancer and male genital cancer. Crohn's disease patients seemed to have a higher risk of prostate cancer and bladder cancer, and ulcerative colitis patients seemed to have a higher risk of prostate cancer. ulcerative colitis patients in East Asian countries have significantly increased prostate cancer risk.

Is imidafenacin an alternative to current antimuscarinic drugs for patients with overactive bladder syndrome?

PURPOSE: Previous studies have included a limited number of randomized controlled trials (RCTs) and compared limited parameters after treatment with imidafenacin and other anticholinergic drugs (ADs) for overactive bladder syndrome (OAB), and controversy about the superiority of these ADs still remains. We aim to update the evidence and provide better clinical guidance. METHODS: A systematic search of PubMed, Embase, ClinicalTrial.gov and Cochrane Library Central Register of Controlled Trials was conducted from January 2007 to April 2019. Meta-analysis of all published RCTs comparing imidafenacin with other ADs in patients with OAB was performed. The primary outcomes were the changes in OAB symptoms and OAB symptom score (OABSS). Secondary outcomes included adverse events (AEs) and the dropout rate related to AEs. RESULTS: A total of 6 studies including 7 RCTs involving 1430 patients with mean follow-up of 23.43 weeks were included. All ADs improved OAB symptoms. Regarding efficacy, these drugs had similar efficacy in voids, urgency episodes, urgency incontinence episodes, incontinence episodes and OABSS. However, imidafenacin performed better in the reduction of nocturia episodes (MD = -0.24, 95% CI -0.44 to -0.04, P = 0.02). Moreover, imidafenacin was associated with a statistically lower dry mouth rate (RR = 0.87, 95% CI 0.75-1.00, P = 0.04), lower constipation rate (RR = 0.68, 95% CI 0.50-0.93, P = 0.01) and lower AE-related withdrawal rate (RR = 0.51, 95% CI 0.29-0.89, P = 0.02). There was no significant difference in terms of other complications. CONCLUSIONS: In conclusion, imidafenacin was comparable to other ADs in the treatment of OAB. Moreover, imidafenacin presented a lower dry mouth rate, lower constipation rate and higher adherence and persistence.

Urological second malignant neoplasms in testicular nonseminoma survivors: a population-based analysis.

PURPOSE: Patients with testicular non-seminomatous germ cell tumors in the modern cisplatin-based chemotherapy era show favorable outcomes, yielding survivors exposed to increased risk of second malignant neoplasms. The carcinogenic effects of cisplatin were well established, and its side effects had shown close connections with the urinary system. The study aimed to evaluate how the characteristics of the primary testicular nonseminoma are associated with urological second malignant neoplasms and survival outcomes. METHODS: Using the Surveillance, Epidemiology and End Results database, standardized incidence ratios (SIR) for three major urological tumors including kidney, bladder, and prostate cancer were calculated for 10,734 patients with testicular nonseminoma from 1975 to 2016. The survival analyses were performed using the Kaplan-Meier method and log-rank test, risk factors for overall survival were determined by Cox regression. RESULTS: We identified a total of 197 patients with secondary urological neoplasms. Patients with previous testicular nonseminoma had elevated risk of kidney cancer (SIR 2.13, 95% CI 1.59-2.79), bladder cancer (SIR 1.47, 95% CI 1.07-1.59), and decreased risks of prostate cancer (SIR 0.75, 95% CI 0.61-0.91) compared with the general population. Patients diagnosed with testicular nonseminoma had favorable prognosis with 10-year overall survival reaching 91.8%, and patients with urological second malignant neoplasms showed better prognoses than patients with other second malignant neoplasms (log-rank P < 0.001). CONCLUSION: Testicular nonseminoma survivors showed higher risks of kidney and bladder cancer associated with chemotherapy and decreased risk of prostate cancer. The prognosis of urological second neoplasms was better than other tumor origins.

Holmium laser technologies versus photoselective greenlight vaporization for patients with benign prostatichyperplasia: a meta-analysis.

This study aims to compare the efficacy and safety of holmium laser technologies (HoL-Ts) and photoselective greenlight vaporization (PVP) for the treatment of benign prostatic hyperplasia (BPH), and to perform a meta-analysis according to the Preferred Reporting Items of Systematic Reviews and Meta-Analyses guidelines on PubMed, EMBASE, ClinicalTrial.gov, and the Cochrane Central Register of Controlled Trials up to August 2019. Functional outcomes, perioperative parameters, and complications were included and analyzed. Review Manager 5.3 (Cochrane Collaboration, Oxford, UK) was used to perform all analyses. A total of six articles composed of 2014 patients were included in this review. In comparison with PVP, HoL-Ts had a better performance in 1-, 3-, and 6-month Qmax (P = 0.02, but I2 = 81%), with less postvoid residual urine volume (PVR) (MD = -33.85, 95% CI -52.13 to -15.57, P = 0.0003) and less total energy used (MD = -31.66, 95% CI -58.99 to -4.33, P = 0.02). Moreover, HoL-Ts had a relatively lower risk of conversion rate (OR = 0.08, 95% CI 0.01 to 0.60, P = 0.01) associated with enough enucleation and less intraoperative bleeding. Subgroup analysis of holmium laser enucleation of prostate (HoLEP) versus PVP suggested that HoLEP presented better results in 1-, 3-, 6-month and 1-year Qmax with less PVR, less energy consumption, and lower conversion rate. Compared with PVP, HoL-Ts had higher 1-, 3-, and 6-month Qmax, less PVR, and less total energy consumption with a relatively lower risk of conversion rate. In subgroup analyses, HoLEP had shown better results in accordance with all HoL-Ts. Nevertheless, well-designed RCTs including overall functional indicators are required to confirm our findings.

Menstrual cycle-related fluctuations in breast density measured by using three-dimensional MR imaging.

PURPOSE: To investigate the fluctuation of fibroglandular tissue volume (FV) and percentage of breast density (PD) during the menstrual cycle and compare with postmenopausal women by using three-dimensional magnetic resonance (MR)-based segmentation methods. MATERIALS AND METHODS: This study was approved by the Institutional Review Board and was HIPAA compliant. Written informed consent was obtained. Thirty healthy female subjects, 24 premenopausal and six postmenopausal, were recruited. All subjects underwent MR imaging examination each week for 4 consecutive weeks. The breast volume (BV), FV, and PD were measured by two operators to evaluate interoperator variation. The fluctuation of each parameter measured over the course of the four examinations was evaluated on the basis of the coefficient of variation (CV). RESULTS: The results from two operators showed a high Pearson correlation for BV (R(2) = 0.99), FV (R(2) = 0.98), and PD (R(2) = 0.96). The interoperator variation was 3% for BV and around 5%-6% for FV and PD. In the respective premenopausal and postmenopausal groups, the mean CV was 5.0% and 5.6% for BV, 7.6% and 4.2% for FV, and 7.1% and 6.0% for PD. The difference between premenopausal and postmenopausal groups was not significant (all P values > .05). CONCLUSION: The fluctuation of breast density measured at MR imaging during a menstrual cycle was around 7%. The results may help the design and interpretation of future studies by using the change of breast density as a surrogate marker to evaluate the efficacy of hormone-modifying drugs for cancer treatment or cancer prevention.

Analysis of gene expression profile of periodontal ligament cells subjected to cyclic compressive force.

Cyclic compressive force is an important mechanical stimulus on periodontal ligament (PDL). The differential expression of genes in PDL cells is thought to be involved in the remodeling of periodontal tissues subjected to mechanical stress. However, little is known about differentially expressed genes in PDL cells under cyclic compressive force. In our study, human PDL cells were subjected to 4000 µ strain compressive stress loading at 0.5 Hz for 2 h. The effect of mechanical stress on PDL cells proliferation was observed by flow cytometry. Microarray analysis was used to investigate the mechano-induced differential gene profile in PDL cells. Differential expression was confirmed by quantitative real-time polymerase chain reaction (RT-PCR) analysis on genes of interest and explored at two more force loading times (6 h, 12 h). After mechanical loading, cell proliferation was repressed. The microarray data showed that 217 out of 35,000 genes were differentially expressed; among the 217 genes, 207 were up-regulated whereas 10 were down-regulated (p < 0.05). Gene ontology analysis suggested that majority of differentially expressed genes were located in the nucleus and functioned as transcription factors involved in a variety of biological processes. Five genes of interest (IL6, IL8, ETS1, KLF10, and DLC1) were found to be closely related to negative regulation of cell proliferation. The PCR results showed increased expression after 2 h loading, then a decline with extended loading time. The signaling pathways involved were also identified. These findings expand understanding of molecular regulation in the mechano-response of PDL cells.

Early proliferation alteration and differential gene expression in human periodontal ligament cells subjected to cyclic tensile stress.

OBJECTIVE: The study was aimed to provide insights into genes governing the early stages of cell proliferation ability alteration and mechano-response in human periodontal ligament cells (PDLCs) induced by short-term cyclic tensile stress. MATERIALS AND METHODS: Primary human PDLCs were subjected to cyclic tensile stress (0.5 Hz, 5000 µstrain) for 2h through a four-point bending strain system. After that, cell viability and proliferation ability were examined by MTT [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometry. Furthermore, the gene expression profile was investigated by microarray analysis, and the reliability of which was verified by quantitative RT-PCR. RESULTS: MTT assay and flow cytometry demonstrated that mechanical stress inhibited functional expression and slowed down proliferation of cells. Microarray analysis showed that 110 genes related to cyclic tensile stress were identified in total. Amongst them, ninety-seven were up-regulated, whilst 13 were down-regulated. Eleven genes (KLF10, ETS1, CKS2, DUSP6, KIF23, MAPK6, SERTAD1, IRF1, MAPRE1, CCNB1 and BCAR3) regarding cell cycle arrest were identified. Seven up-regulated genes (PTGS2, KLF10, CDC42EP2, BHLHB2, SPRY2, IER3 and CCL2) were verified by quantitative RT-PCR, which supported the microarray results. CONCLUSION: Cell cycle arrest and the slow-down proliferation can benefit PDLCs to have more time to respond to mechanical stimuli, and the differential gene expression reflects the behaviour of cells. Those genes in response to cyclic tensile stress were identified in human PDLCs, some of which are related with the mechano-induced cell cycle arrest.

Osseointegration of orthodontic micro-screws after immediate and early loading.

OBJECTIVE: To investigate the desirable healing time of micro-screws by histomorphologic and histomorphometric evaluations of osseointegration after immediate and early loading. MATERIALS AND METHODS: Fifty-four micro-screws were bilaterally placed in the maxillary premolar regions of nine beagles. Then the micro-screws with various healing time of 0 day (0D group), 2 weeks (2W group), and 4 weeks (4W group) were loaded with an orthodontic force (100 g) for 8 weeks. The direction of the orthodontic force was vertical to the long axis of the micro-screws. Hard tissue sections containing micro-screws were prepared for histomorphologic and histomorphometric evaluations. RESULTS: The survival rate of the micro-screws in this study was 100%. Bone remodeling, close contact bone-implant interface, and endochondral ossification were observed in all osseous specimens. Activated osteoblasts aggregated to the bone-implant interface of the 4W group, and lamellar bone was found in the peri-implant regions. Micro-screws of the 2W group were partially surrounded by collagen fibers; and neonatal lines of bone, woven bone, and osteoclasts were found in the peri-implant regions. Micro-screws of the 0D group were surrounded by more collagen fibers compared with the other two groups. Bone implant contact ratios of the three groups were 43.74% (0D group), 66.26% (2W group), and 73.28% (4W group), respectively and statistical differences were significant (ANOVA, P < .01). CONCLUSION: All micro-screws in the three groups can provide stable orthodontic anchorage. However, to obtain improved stationary anchorage, a 4-week healing time is recommended before orthodontic loading.

Up-regulated alpha-actin expression is associated with cell adhesion ability in 3-D cultured myocytes subjected to mechanical stimulation.

This study was aimed to investigate the alteration of alpha-actin in three-dimensionally (3-D) cultured myocytes under cyclic tensile stress loading. Myocytes were collected from neonatal SD rat's lateral pterygoid muscle for primary cell culture. The third-passage cells were implanted and 3-D cultured in poly lactic-co-glycolic acid (PLGA) scaffold, and then subjected to cyclic tensile stress (0.5 Hz, 2,000 microstrain) for 0, 2, 4, 8, 12, and 24 h through a four-point bending strain system. The alpha-actin mRNA was investigated by semi-quantitative RT-PCR. The alpha-actin protein expression was examined by immunofluorescent cytochemistry, laser confocal scanning microscopy (LCSM), and image analysis technology. The dynamic adhesion of myocytes to PLGA scaffolds was investigated by fluorescence microscope and the viability of the myocytes was measured by MTT assay. After mechanical loading, the alpha-actin mRNA increased at 2 h and then declined. The alpha-actin protein expression kept increased until peaked at 12 h, but declined at 24 h. The time course changing of alpha-actin protein expression parallelled with that of cell adhesion ability. It is concluded that alpha-actin expression is probably associated with cell adhesion ability in myocytes subjected to mechanical stimulation.

Aggregation behavior of a fluorinated surfactant in 1-butyl-3-methylimidazolium ionic liquids.

The aggregation behavior of a fluorinated surfactant (FC-4) was studied by surface tension measurements in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF 4]) and hexafluorophosphate ([bmim][PF 6]) at various temperatures. A series of surface properties, including adsorption efficiency (p C 20), effectiveness of surface tension reduction (Pi CAC), maximum surface excess concentration (Gamma max) and minimum surface area/molecule (A(min)) at the air-water interface were estimated. By comparing the fluorinated surfactant with traditional surfactants, we deduced that the surface activity of the fluorinated surfactant in ILs was superior to the activity of other surfactants. From the CAC values and their temperature dependence, we estimated the thermodynamic parameters of aggregate formation. The thermodynamic parameters indicate that the aggregate of FC-4 in [bmim][BF 4] is a traditional micelle, while the aggregate of FC-4 in [bmim][PF 6] is nanodroplets composed of FC-4 molecules segregated from the solution phase. These results were further confirmed by (1)H NMR measurements.

Aggregation behavior of polyoxyethylene (20) sorbitan monolaurate (tween 20) in imidazolium based ionic liquids.

Surface tension measurements were carried out for the solutions of polyoxyethylene (20) sorbitan monolaurate (Tween 20) in 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF 4) and hexafluorophosphate (bmimPF 6) at various temperatures. Two transition points were found in the surface tension-concentration curves at each temperature. The freeze-fracture transmission electron microscopy revealed that two kinds of particles with different sizes are formed at the concentrations of each transition point. Thus, the surfactant concentrations of the two transition points are regarded as critical aggregation concentrations, CAC 1 and CAC 2. From the CAC values and their temperature dependence, we estimated the thermodynamic parameters of the aggregate formation, Delta G agg (0), Delta H agg (0), and Delta S agg (0). The thermodynamic parameters related to CAC 1 are almost independent of temperature. On the other hand, as for the aggregate formation at CAC 2, a positiveDelta S agg (0) contributes to a negative Delta G agg (0) at low temperature, while a negative Delta H agg (0) contributes to a negative Delta G agg (0) at high temperature. The behavior of the thermodynamic parameters as a function of temperature, combined with the variation of (1)H NMR chemical shifts of the bmim (+) protons as a function of the surfactant concentration, demonstrated that the aggregates formed at CAC 1 are nanodroplets of Tween 20 segregated from the solution phase, while those formed at CAC 2 are similar to the usual surfactant micelles formed in aqueous solution.