Changyong Feng

Sex and racial differences in bladder cancer presentation and mortality in the US

Sex, race, and age at diagnosis have a significant impact on mortality from bladder cancer (BC). Women, African Americans of both sexes, and the elderly, all experience higher mortality rates. Tumor grade, stage, and histologic type at presentation also affect outcome. To determine whether age and tumor characteristics alone explain the excess hazard of death from BC observed in some demographic groups, the authors queried the Surveillance, Epidemiology, and End Results (SEER) limited‐use database for the presentations of and outcomes from BC between 1990 and 2005.

Effect of mifepristone for symptomatic leiomyomata on quality of life and uterine size: a randomized controlled trial.

OBJECTIVE: To assess the effect of low-dose mifepristone on quality of life, pain, bleeding, and uterine size among women with symptomatic leiomyomata. METHODS: Forty-two women with symptomatic uterine leiomyomata and uterine volume of 160 mL or more were randomized to mifepristone, 5 mg daily, or placebo for 26 weeks. Quality of life (Uterine Fibroid Symptoms Quality of Life Questionnaire and Medical Outcomes Study 36-Item Short Form survey) and uterine and leiomyoma size (ultrasonography) were assessed at baseline, and at 1 month, 3 months, and 6 months of treatment. Bleeding (daily logs and pictorial charts) and pain (McGill Pain Questionnaire) were assessed monthly. Endometrial pathology was assessed at baseline and 6 months. RESULTS: Forty-two women were randomized; 37 women completed all 6 months. Women randomized to mifepristone showed an improvement in leiomyoma-specific quality of life. Forty-one percent became amenorrheic, rates of anemia improved, and adjusted uterine size was reduced by 47%. Compared with the placebo group, improvements in these outcomes in the treatment group were significantly greater (P<.05 to .001). There were no significant differences in adverse effects between the groups. No endometrial hyperplasia was noted in any participant. CONCLUSION: Low-dose mifepristone improves leiomyoma-specific quality of life and reduces leiomyoma size among women with symptomatic leio-myomata. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov www.clinicaltrials.gov NCT00133705 LEVEL OF EVIDENCE: I

Long-term outcome of hematuria home screening for bladder cancer in men

The objectives of this study were to determine whether bladder cancer (BC) screening in healthy men could lead to earlier detection and reduced BC mortality compared with unscreened men and to determine long‐term outcomes of a geographically defined, unscreened population with newly diagnosed BC.

CD16 (FcRγIII) as a potential marker of osteoclast precursors in psoriatic arthritis

IntroductionPsoriatic arthritis (PsA) is a chronic inflammatory arthritis characterized by bone erosion mediated by osteoclasts (OC). Our previous studies showed an elevated frequency of OC precursors (OCP) in PsA patients. Here, we examined if OC arise from CD16-positive monocytes in PsA.MethodsPeripheral blood mononuclear cells (PBMC) or monocytes were isolated from human peripheral blood and sorted based on CD16 expression. Sorted cells were cultured alone or with bone wafers in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Enumeration and bone erosion activity of OC were examined after culture. The effects of tumor necrosis factor-alpha (TNFα), OC-promoting (M-CSF plus RANKL), and dendritic cell (DC)-promoting (GM-CSF plus interleukin (IL)-4) cytokines on CD16 surface expression were examined by flow cytometry.ResultsPsA and psoriasis (Ps) subjects had a higher percentage of circulating inflammatory CD14+CD16+ cells than healthy controls (HC). Exposure of cells to OC-promoting, but not DC-promoting media, was associated with CD16 up-regulation. PBMC of Ps and PsA had a higher frequency of cells expressing intermediate levels of CD16. OC were mainly derived from CD16+ cells in PsA. Increased CD16 expression was associated with a higher bone erosion activity in PsA.ConclusionsAn increased frequency of circulating CD14+CD16+ cells was noted in PsA compared to controls, and intermediate levels of CD16 may suggest a transitional state of OCP during osteoclastogenesis. Intriguingly, TNFα blocked CD16 expression on a subset of CD14+ monocytes. Collectively, our data suggest that CD16 has the potential to serve as an OCP marker in inflammatory arthritis.

Log-transformation and its implications for data analysis

Summary The log-transformation is widely used in biomedical and psychosocial research to deal with skewed data. This paper highlights serious problems in this classic approach for dealing with skewed data. Despite the common belief that the log transformation can decrease the variability of data and make data conform more closely to the normal distribution, this is usually not the case. Moreover, the results of standard statistical tests performed on log-transformed data are often not relevant for the original, non-transformed data.We demonstrate these problems by presenting examples that use simulated data. We conclude that if used at all, data transformations must be applied very cautiously. We recommend that in most circumstances researchers abandon these traditional methods of dealing with skewed data and, instead, use newer analytic methods that are not dependent on the distribution the data, such as generalized estimating equations (GEE).

Peak frequencies of circulating human influenza-specific antibody secreting cells correlate with serum antibody response after immunization ☆

UNLABELLED Upon vaccination, B cells differentiate into antibody secreting cells (ASCs) that migrate via the circulation to tissues. The kinetics of this response and the relationship of circulating ASCs to protective antibody titers have not been completely explored. METHODS Influenza-specific and total-IgG ASCs were enumerated by Elispot and flow cytometry daily in the blood in 6 healthy adults after trivalent influenza vaccination (TIV). RESULTS Peak H1-specific IgG ASC frequencies occurred variably from day 5 to 8 and correlated with the fold-rise rise in hemagglutination inhibition (HAI titers); r=0.91, p=0.006. H3-specific IgG ASC frequencies correlated less well, perhaps due to a mismatch of the H3 protein in the vaccine and that used in the Elispot assay. Peak frequencies of vaccine-specific and total-IgG ASCs were 0.3% and 0.8%, respectively, of peripheral blood mononuclear cells (PBMC). Peak TIV-, H1-, H3-, and total-IgG ASC frequencies were 1736+/-1133, 626+/-520, 592+/-463, and 4091+/-2019 spots/10(6) PBMC, respectively. Peak TIV-, H1-, and H3-specific IgG ASC of total-IgG ASC frequencies constituted 63%+/-21, 26%+/-10, 22%+/-17, respectively. CONCLUSION After immunization with inactivated influenza vaccine the peak in influenza-specific ASC frequencies is variable but correlates well with the magnitude of protective HAI responses.

The Effect of Core Material, Veneering Porcelain, and Fabrication Technique on the Biaxial Flexural Strength and Weibull Analysis of Selected Dental Ceramics

PURPOSE The objective of this study was to compare the effect of veneering porcelain (monolithic or bilayer specimens) and core fabrication technique (heat-pressed or CAD/CAM) on the biaxial flexural strength and Weibull modulus of leucite-reinforced and lithium-disilicate glass ceramics. In addition, the effect of veneering technique (heat-pressed or powder/liquid layering) for zirconia ceramics on the biaxial flexural strength and Weibull modulus was studied. MATERIALS AND METHODS Five ceramic core materials (IPS Empress Esthetic, IPS Empress CAD, IPS e.max Press, IPS e.max CAD, IPS e.max ZirCAD) and three corresponding veneering porcelains (IPS Empress Esthetic Veneer, IPS e.max Ceram, IPS e.max ZirPress) were selected for this study. Each core material group contained three subgroups based on the core material thickness and the presence of corresponding veneering porcelain as follows: 1.5 mm core material only (subgroup 1.5C), 0.8 mm core material only (subgroup 0.8C), and 1.5 mm core/veneer group: 0.8 mm core with 0.7 mm corresponding veneering porcelain with a powder/liquid layering technique (subgroup 0.8C-0.7VL). The ZirCAD group had one additional 1.5 mm core/veneer subgroup with 0.7 mm heat-pressed veneering porcelain (subgroup 0.8C-0.7VP). The biaxial flexural strengths were compared for each subgroup (n = 10) according to ISO standard 6872:2008 with ANOVA and Tukeys post hoc multiple comparison test (p≤ 0.05). The reliability of strength was analyzed with the Weibull distribution. RESULTS For all core materials, the 1.5 mm core/veneer subgroups (0.8C-0.7VL, 0.8C-0.7VP) had significantly lower mean biaxial flexural strengths (p < 0.0001) than the other two subgroups (subgroups 1.5C and 0.8C). For the ZirCAD group, the 0.8C-0.7VL subgroup had significantly lower flexural strength (p= 0.004) than subgroup 0.8C-0.7VP. Nonetheless, both veneered ZirCAD groups showed greater flexural strength than the monolithic Empress and e.max groups, regardless of core thickness and fabrication techniques. Comparing fabrication techniques, Empress Esthetic/CAD, e.max Press/CAD had similar biaxial flexural strength (p= 0.28 for Empress pair; p= 0.87 for e.max pair); however, e.max CAD/Press groups had significantly higher flexural strength (p < 0.0001) than Empress Esthetic/CAD groups. Monolithic core specimens presented with higher Weibull modulus with all selected core materials. For the ZirCAD group, although the bilayer 0.8C-0.7VL subgroup exhibited significantly lower flexural strength, it had highest Weibull modulus than the 0.8C-0.7VP subgroup. CONCLUSIONS The present study suggests that veneering porcelain onto a ceramic core material diminishes the flexural strength and the reliability of the bilayer specimens. Leucite-reinforced glass-ceramic cores have lower flexural strength than lithium-disilicate ones, while fabrication techniques (heat-pressed or CAD/CAM) and specimen thicknesses do not affect the flexural strength of all glass ceramics. Compared with the heat-pressed veneering technique, the powder/liquid veneering technique exhibited lower flexural strength but increased reliability with a higher Weibull modulus for zirconia bilayer specimens. Zirconia-veneered ceramics exhibited greater flexural strength than monolithic leucite-reinforced and lithium-disilicate ceramics regardless of zirconia veneering techniques (heat-pressed or powder/liquid technique).

Regulation of Human Osteoclast Development by Dendritic Cell-Specific Transmembrane Protein (DC-STAMP)

Osteoclasts (OC) are bone‐resorbing, multinucleated cells that are generated via fusion of OC precursors (OCP). The frequency of OCP is elevated in patients with erosive inflammatory arthritis and metabolic bone diseases. Although many cytokines and cell surface receptors are known to participate in osteoclastogenesis, the molecular mechanisms underlying the regulation of this cellular transformation are poorly understood. Herein, we focused our studies on the dendritic cell‐specific transmembrane protein (DC‐STAMP), a seven‐pass transmembrane receptor‐like protein known to be essential for cell‐to‐cell fusion during osteoclastogenesis. We identified an immunoreceptor tyrosine‐based inhibitory motif (ITIM) in the cytoplasmic tail of DC‐STAMP, and developed an anti‐DC‐STAMP monoclonal antibody 1A2 that detected DC‐STAMP expression on human tumor giant cells, blocked OC formation in vitro, and distinguished four patterns of human PBMC with a positive correlation to OC potential. In freshly isolated monocytes, DC‐STAMPhigh cells produced a higher number of OC in culture than DC‐STAMPlow cells and the surface expression of DC‐STAMP gradually declined during osteoclastogenesis. Importantly, we showed that DC‐STAMP is phosphorylated on its tyrosine residues and physically interacts with SHP‐1 and CD16, an SH2‐domain‐containing tyrosine phosphatase and an ITAM‐associated protein, respectively. Taken together, these data show that DC‐STAMP is a potential OCP biomarker in inflammatory arthritis. Moreover, in addition to its effect on cell fusion, DC‐STAMP dynamically regulates cell signaling during osteoclastogenesis.

On fitting generalized linear mixed‐effects models for binary responses using different statistical packages

The generalized linear mixed-effects model (GLMM) is a popular paradigm to extend models for cross-sectional data to a longitudinal setting. When applied to modeling binary responses, different software packages and even different procedures within a package may give quite different results. In this report, we describe the statistical approaches that underlie these different procedures and discuss their strengths and weaknesses when applied to fit correlated binary responses. We then illustrate these considerations by applying these procedures implemented in some popular software packages to simulated and real study data. Our simulation results indicate a lack of reliability for most of the procedures considered, which carries significant implications for applying such popular software packages in practice.

Effect of subgingival depth of implant placement on the dimensional accuracy of the implant impression: An in vitro study

STATEMENT OF PROBLEM In some instances, an implant needs to be placed deep subgingivally, which may result in a less accurate impression of the implant. PURPOSE.: The purpose of this study was to evaluate the effect of subgingival depth of implant placement on the accuracy of implant impressions. MATERIAL AND METHODS A stone master model was fabricated with 5 implant analogs (RN synOcta analog), embedded parallel to each other, at the center (E) and the 4 corners (A, B, C, and D). The vertical position of the shoulders of the implants was intentionally different among the implants: A and E were flush with the top surface of the model; B was 2 mm below, and C and D were 4 mm below the surface. The horizontal distances of implants A, B, C, and D from E were measured with a measuring microscope. A cross-shaped metal measuring bar was then fabricated and connected to E, with the arms of the casting designed to be 2 mm above the top surface of the model and incorporating a reference mark. With the measuring bar connected to E, the vertical distances from the apical surface of A, B, C, and D to the measuring reference marks were measured with a digital micrometer. The body of the impression coping for implant D was modified by adding 4 mm of additional impression coping, while standard impression copings were used for all other implants. Open tray impressions were made using medium-body polyether material (Impregum Penta) or a combination of putty and light-body vinyl polysiloxane (VPS) material (Elite HD+) (n=15). Then casts were poured with type IV dental stone. The vertical and horizontal distances of the casts were measured with the methods outlined above for the master model. The distortion values that were determined as differences between the measurements of the master model and those of the casts were collected for statistical analysis. Two-way and 1-way repeated measures ANOVA followed by Tukeys HSD test were performed to compare the distortion values (alpha=.05). RESULTS For vertical measurements, 2-way repeated measures ANOVA showed no significant depth (P=.36), material (P=.24), or interaction effects (P=.06). However, it showed significant depth effect for horizontal measurements (P=.01). Within the polyether group, 1-way repeated measures ANOVA showed significant differences in horizontal measurements among the implants with different depths (P=.03). The post hoc Tukeys test showed that the impression of 4-mm-deep implants with normal impression copings (C) was significantly less accurate than impressions of 0-mm-deep implants (A) (P=.02). Within the VPS group, there was no significant difference among the implants with different depths (P=.09). CONCLUSIONS There was no effect of implant depth on the accuracy of the VPS group. However, for the polyether group, the impression of an implant placed 4 mm subgingivally showed a greater horizontal distortion compared to an implant placed more coronally. Adding a 4-mm extension to the retentive part of the impression coping eliminated this difference.