Thermostability and binding properties of single-chained Fv fragments derived from therapeutic antibodies.

Small antibody fragments have recently been used as alternatives to full-length monoclonal antibodies in therapeutic applications. One of the most popular fragment antibodies is single-chain fragment variables (scFvs), consisting of variable heavy (VH) and variable light (VL) domains linked by a flexible peptide linker. scFvs have small molecular sizes, which enables good tissue penetration and low immunogenicity. Despite these advantages, the use of scFvs, especially for therapeutic purpose, is still limited because of the difficulty to regulate the binding activity and conformational stability. In this study, we constructed and analyzed 10 scFv fragments derived from 10 representatives of FDA-approved mAbs to evaluate their physicochemical properties. Differential scanning calorimetry analysis showed that scFvs exhibited relatively high but varied thermostability, from 50 to 70°C of melting temperatures, and different unfolding cooperativity. Surface plasmon resonance analysis revealed that scFvs fragments that exhibit high stability and cooperative unfolding likely tend to maintain antigen binding. This study demonstrated the comprehensive physicochemical properties of scFvs derived from FDA-approved antibodies, providing insights into antibody design and development.

Trk-fused gene plays a critical role in diet-induced adipose tissue expansion and is also involved in thyroid hormone action.

Mutations in the Trk-fused gene (TFG) cause hereditary motor and sensory neuropathy with proximal dominant involvement, which reportedly has high co-incidences with diabetes and dyslipidemia, suggesting critical roles of the TFG in metabolism as well. We found that TFG expression levels in white adipose tissues (WATs) were elevated in both genetically and diet-induced obese mice and that TFG deletion in preadipocytes from the stromal vascular fraction (SVF) markedly inhibited adipogenesis. To investigate its role in vivo, we generated tamoxifen-inducible adipocyte-specific TFG knockout (AiTFG KO) mice. While a marked down-regulation of the peroxisome proliferator-activated receptor gamma target, de novo lipogenesis (DNL), and mitochondria-related gene expressions were observed in subcutaneous WAT (scWAT) from AiTFG KO mice, these effects were blunted in SVF-derived adipocytes when the TFG was deleted after differentiation into adipocytes, implying cell nonautonomous effects. Intriguingly, expressions of thyroid hormone receptors, as well as carbohydrate responsive element-binding protein ß, which mediates the metabolic actions of thyroid hormone, were drastically down-regulated in scWAT from AiTFG KO mice. Reduced DNL and thermogenic gene expressions in AiTFG KO mice might be attributable to impaired thyroid hormone action in vivo. Finally, when adipocyte TFG was deleted in either the early or the late phase of high-fat diet feeding, the former brought about an impaired expansion of epididymal WAT, whereas the latter caused prominent adipocyte cell death. TFG deletion in adipocytes markedly exacerbated hepatic steatosis in both experimental settings. Collectively, these observations indicate that the TFG plays essential roles in maintaining normal adipocyte functions, including an enlargement of adipose tissue, thyroid hormone function, and thermogenic gene expressions, and in preserving hypertrophic adipocytes.

Multivariate analysis of the effect of keratinized mucosa on peri-implant tissues with platform switching: A retrospective study.

BACKGROUND: In recent years, platform switching implant treatment has been increasing, which is believed to minimize bone loss around the implant after placement. However, there have been no reports on the relationship between keratinized mucosa width (KMW) and bone loss and soft tissue recession in platform switching implants. OBJECTIVE: We evaluated the effect of the KMW on the amount of bone loss and soft tissue recession around a platform switching implant retrospectively using multivariate analysis. MATERIALS AND METHODS: This one-year retrospective study included 91 implants in 48 patients. Age, sex, a history of periodontitis, implant location, oral hygiene status, and the KMW were included as explanatory variables to evaluate bone loss (BL) and buccal gingival height (GH). Generalized estimating equations (GEEs) were used to evaluate the effect of the KMW on platform switching peri-implant tissues. RESULTS: The mean bone loss on the mesial (ΔBLm), distal (ΔBLd), and buccal (ΔBLb) sides of the implant were 0.16 ± 0.27 mm, 0.19 ± 0.34 mm, and 0.24 ± 0.50 mm, respectively, at 1 year after superstructure placement. The mean amount of change of GH (ΔGH) on the buccal side was 0.30 ± 0.47 mm. After correcting for confounders using GEEs, the results suggested that KMW <1.5 mm was a significant factor (P < 0.001) for bone loss over time in ΔBLm, ΔBLd, and ΔBLb. In addition, for soft tissues on the buccal side, KMW <1.5 mm was a significant factor for ΔGH reduction over time (P < 0.001). CONCLUSIONS: Keratinized mucosa width ≥1.5 mm was associated with a higher probability less hard and soft tissue recession around the platform switching implant after 1 year from superstructure placement.

Psychological Barriers to the Use of Opioid Analgesics for Treating Pain in Patients With Advanced Recurrent Cancer: A Multicenter Cohort Study.

Background: We aimed to gain insight into psychological barriers toward initiation of strong opioid analgesic use in patients with advanced recurrent cancer. Methods: This study included 46 patients who were prescribed with opioid analgesics for advanced recurrent cancer. The primary outcome was psychological barriers assessed using the Japanese version of the Barriers Questionnaire-II (JBQ-II). The secondary outcomes were psychological changes and pain relief one week after the induction of strong opioid analgesics. Results: The mean age of participants was 63.6 years. Furthermore, 26.1% had an Eastern Cooperative Oncology Group (ECOG) performance status of ≥3. The mean JBQ-II total score was 1.97 (95% confidence interval: 1.75-2.19). At the initiation of opioid therapy, there was no difference in the total scores between the baseline and one week later. Nevertheless, there was a significant difference in the subscale "disease progression" score (mean 2.97 vs. 2.59, difference in means 0.38, standard error 0.16, p = 0.026). Personalized Pain Goal (PPG) was achieved in about half of the participants, and a trend toward a higher score in the subscale "harmful effects" (concern about adverse events) was observed in those who did not achieve PPG. Conclusion: This study showed that patients with advanced recurrent cancer have psychological barriers to opioid induction. The relationship between the presence of psychological barriers before and after induction of opioid analgesics and the speed of pain improvement was determined. The results may provide fundamental information for prospective intervention studies to develop individualized education programs for patients with psychological barriers to opioids.Clinical Trial Registration Number UMIN000042443.

An immunocytokine consisting of a TNFR2 agonist and TNFR2 scFv enhances the expansion of regulatory T cells through TNFR2 clustering.

Regulatory T cells (Tregs) are lymphocytes that play a central role in peripheral immune tolerance. Tregs are promising targets for the prevention and suppression of autoimmune diseases, allergies, and graft-versus-host disease, and treatments aimed at regulating their functions are being developed. In this study, we created a new modality consisting of a protein molecule that suppressed excessive immune responses by effectively and preferentially expanding Tregs. Recent studies reported that tumor necrosis factor receptor type 2 (TNFR2) expressed on Tregs is involved in the proliferation and activation of Tregs. Therefore, we created a functional immunocytokine, named TNFR2-ICK-Ig, consisting of a fusion protein of an anti-TNFR2 single-chain Fv (scFv) and a TNFR2 agonist TNF-α mutant protein, as a new modality that strongly enhances TNFR2 signaling. The formation of agonist-receptor multimerization (TNFR2 cluster) is effective for the induction of a strong TNFR2 signal, similar to the TNFR2 signaling mechanism exhibited by membrane-bound TNF. TNFR2-ICK-Ig improved the TNFR2 signaling activity and promoted TNFR2 cluster formation compared to a TNFR2 agonist TNF-α mutant protein that did not have an immunocytokine structure. Furthermore, the Treg expansion efficiency was enhanced. TNFR2-ICK-Ig promotes its effects via scFv, which crosslinks receptors whereas the agonists transmit stimulatory signals. Therefore, this novel molecule expands Tregs via strong TNFR2 signaling by the formation of TNFR2 clustering.

Bivalent structure of a TNFR2-selective and agonistic TNF-α mutein Fc-fusion protein enhances the expansion activity of regulatory T cells.

Recently, TNF receptor type 2 (TNFR2) signaling was found to be involved in the proliferation and activation of regulatory T cells (Tregs), a subpopulation of lymphocytes that suppress immune responses. Tregs mediate peripheral immune tolerance, and the disruption of their functions causes autoimmune diseases or allergy. Therefore, cell expanders or regulators of Tregs that control immunosuppressive activity can be used to treat these diseases. We focused on TNFR2, which is preferentially expressed on Tregs, and created tumor necrosis factor-α (TNF-α) muteins that selectively activate TNFR2 signaling in mice and humans, termed R2agoTNF and R2-7, respectively. In this study, we attempted to optimize the structure of muteins to enhance their TNFR2 agonistic activity and stability in vivo by IgG-Fc fusion following single-chain homo-trimerization. The fusion protein, scR2agoTNF-Fc, enhanced the expansion of CD4+CD25+ Tregs and CD4+Foxp3+ Tregs and contributed to their immunosuppressive activity ex vivo and in vivo in mice. The prophylactic administration of scR2agoTNF-Fc suppressed inflammation in contact hypersensitivity and arthritis mouse models. Furthermore, scR2-7-Fc preferentially expanded Tregs in human peripheral blood mononuclear cells via TNFR2. These TNFR2 agonist-Fc fusion proteins, which have bivalent structures, are novel Treg expanders.

Arthroscopic Bankart repair with peeling osteotomy of the anterior glenoid rim preserves glenoid morphology.

BACKGROUND: A decrease in the glenoid size after arthroscopic Bankart repair (ABR) was common in shoulders without osseous fragments compared with those with osseous fragments. For cases of chronic recurrent traumatic anterior glenohumeral instability without osseous fragments, we have performed ABR with peeling osteotomy of the anterior glenoid rim (ABRPO) to make an intentional osseous Bankart lesion. The aim of this study was to compare the glenoid morphology after ABRPO with it after simple ABR. METHODS: The medical records of patients who underwent arthroscopic stabilization for chronic recurrent traumatic anterior glenohumeral instability were retrospectively reviewed. Patients with an osseous fragment, with revision surgery and without complete data were excluded. Patients were assigned to 1 of 2 groups: Group A, ABR without peeling osteotomy procedure or Group B, with ABRPO procedure. Computed tomography was performed preoperatively and 1 year after surgery. The size of the glenoid bone loss was investigated by the assumed circle method. The following formula was used to calculate the decreased size of the glenoid: (Δ) = (postoperative size of the glenoid bone loss) - (preoperative size of the glenoid bone loss). The size of the glenoid 1 year after surgery was assessed to determine if it had decreased (Δ > 0%) or not decreased (Δ ≤ 0%) relative to the preoperative size. RESULTS: This study evaluated 39 shoulders divided into 2 groups: 27 shoulders in Group A and 12 shoulders in Group B. In Group A, postoperative glenoid bone loss was significantly greater than preoperative glenoid bone loss (7.8 ± 6.2 vs. 5.5 ± 5.3, respectively, P = .02). In Group B, postoperative glenoid bone loss was significantly lower than preoperative glenoid bone loss (5.6 ± 5.4 vs. 8.7 ± 4.0, respectively, P = .02). The P value for the interaction of group (A or B) × time (preoperative or postoperative) was 0.001. The decreased size of the glenoid was significantly larger in Group A than in Group B (2.1 ± 4.2 vs. -3.1 ± 4.5, respectively, P = .001). The rate of shoulders in which the size of the glenoid decreased 1 year after surgery relative to the preoperative size was significantly higher in Group A than in Group B (63% [17/27] vs. 25% [3/2], respectively, P = .04). CONCLUSIONS: The study showed that ABRPO preserved the glenoid size better than simple ABR without a peeling osteotomy procedure.

Effects of activation of an alcohol metabolic gene, cigarette smoking, and alcohol intake on the incidence of metachronous gastric cancer in patients who underwent endoscopic resection for gastric cancer: A multicenter retrospective pilot study.

Background and Aim: Metachronous gastric cancer (GC) frequently occurs in patients who have undergone endoscopic resection (ER) for GC. We evaluated the risk for development of metachronous GC following ER for GC based on genetic polymorphisms for alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2), as well as alcohol consumption and smoking habits. Methods: We studied 77 patients who underwent ER for GC (median follow-up of 84 months). Genotyping of ADH1B/ALDH2 was performed using saliva sampling. Histories of alcohol consumption and smoking before and after ER and Helicobacter pylori eradication were documented. Results: Multivariate analyses revealed that homozygous slow-metabolizing ADH1B (hazard ratio [HR] = 2.38, P < 0.13), heavy smoking (HR = 2.36, P < 0.09), and cigarette smoking after ER (HR = 2.47, P < 0.10) were not independently associated with the risk of secondary GC development. We analyzed the cessation status of the 38 patients who were classified as heavy smokers before ER based on their smoking habits after the ER and divided them into a cessation group (n = 27, non-smokers after ER) and a non-cessation group (n = 11). Cumulative incidence curves of secondary GC in the cessation and non-cessation groups revealed 5-year incidence rates of 19.0% and 45.0%, respectively (P = 0.02). Conclusion: Continued cigarette smoking, at a high level, may be an important risk factor for the development of metachronous GC. Advice for smoking cessation should be given.

Infection with male and female Trichuris trichiura diagnosed in a non-endemic area.

Trichuris trichiura parasitizes only humans through fecal-oral transmission. In non-endemic areas, the frequency of endoscopic identification has been increasing due to the increasing number of immigrants from endemic countries. To prevent infection, it is important to pay attention to sanitary conditions such as soil and water sources.

Optical biopsy for esophageal squamous cell neoplasia by using endocytoscopy.

BACKGROUND: Endocytoscopy (ECS) enables microscopic observation in vivo for the gastrointestinal mucosa; however, there has been no prospective study in which the diagnostic accuracy of ECS for lesions that have not yet undergone histological diagnosis was evaluated. We conducted a surveillance study for patients in a high-risk group of esophageal squamous cell carcinoma (ESCC) and evaluated the in vivo histological diagnostic accuracy of ECS. METHODS: This study was a multicenter prospective study. We enrolled 197 patients in the study between September 1, 2019 and November 30, 2020. The patients first underwent white light imaging and narrow band imaging, and ultra-high magnifying observation was performed if there was a lesion suspected to be an esophageal tumor. Endoscopic submucosal dissection (ESD) was later performed for lesions that were diagnosed to be ESCC by ECS without biopsy. We evaluated the diagnostic accuracy of ECS for esophageal tumorous lesions. RESULTS: ESD was performed for 37 patients (41 lesions) who were diagnosed as having ESCC by ECS, and all of them were histopathologically diagnosed as having ESCC. The sensitivity [95% confidence interval (CI)] was 97.6% (87.7-99.7%), specificity (95% CI) was 100% (92.7-100%), diagnostic accuracy (95% CI) was 98.9% (94.0-99.8%), positive predictive value (PPV) (95% CI) was 100% (91.4-100%) and negative predictive value (NPV) (95% CI) was 98.0% (89.5-99.7%). CONCLUSIONS: ECS has a high diagnostic accuracy and there were no false positives in cases diagnosed and resected as ESCC. Optical biopsy by using ECS for esophageal lesions that are suspected to be tumorous is considered to be sufficient in clinical practice.

Eradication of Helicobacter pylori may improve dyspepsia in the elderly for the long term.

BACKGROUND: Therapy for eradication of Helicobacter pylori (H. pylori) improves symptoms of H. pylori-associated dyspepsia (HPD), but the effects of eradication in elderly patients are unclear. The aim of our study was to investigate dyspepsia symptoms and long-term effects of eradication in elderly patients. METHODS: This retrospective study included 496 patients who received H. pylori eradication therapy. The patients were divided into a group of elderly patients (group E: ≧ 65 years old) and a group of non-elderly patients (group N: < 65 years old). Abdominal symptoms were evaluated using a questionnaire about abdominal symptoms before eradication and after eradication (1-2 months and more than one year). Dyspepsia was defined as a score of 4 points or more for at least one of 4 items (postprandial fullness, early satiety, epigastric pain, and hunger pain). Improvement of symptoms was defined on the basis of changes in Global Overall Systems scores. RESULTS: There were no differences in abdominal symptoms before eradication between the two groups. Successful eradication improved symptoms in patients with dyspepsia within 2 months (in 75.6% (56/74) of the patients in group N and in 64.5% (20/31) of the patients in group E). The questionnaire showed that 80% (32/40) of the patients in group N and 60% (12/20) of the patients in group E had long-term relief of dyspepsia. The scores for abdominal symptoms in group E continued to improve for a mean period of 54.8 months after eradication. CONCLUSIONS: Eradication of H. pylori age-independently improved dyspepsia symptoms for the long term.

Evaluation of the risk of metachronous multiple squamous cell carcinoma of the head and neck after transoral surgery based on the genetic polymorphisms of alcohol dehydrogenase 1B and aldehyde dehydrogenase 2.

Patients with superficial head and neck squamous cell carcinoma (HNSCC) can be completely treated by techniques of transoral surgery (TOS). The aim of this study was to evaluate the risk of metachronous multiple HNSCC arising after TOS based on alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2). We registered patients who underwent TOS for superficial HNSCC. Buccal cell samples were obtained by using a cotton swab to examine two single nucleotide polymorphisms in ADH1B and ALDH2 genotyping. We used Cox proportional hazards models to examine the risk of metachronous HNSCC. A total of 198 patients who underwent TOS for HNSCC were evaluated. In multivariate analysis, risks for second HNSCC were ADH1B*1/*1 [hazard ratio (HR), 1.88; 95% confidence interval (CI), 1.11-3.19; P = 0.02], ALDH2*1/*2 (HR, 2.11; 95% CI, 1.00-5.16; P = 0.048) and alcohol consumption before TOS (HR, 1.17; 95% CI, 1.06-1.27; P = 0.01). The 5-year incidence rates of second primary HNSCC in the temperance group and the non-temperance group were 20.8 and 46.5%, respectively (HR, 0.54; 95% CI, 0.31-0.92; P = 0.02). Cumulative development rates of third HNSCC in the temperance group and non-temperance group at 10 years were 11.3 and 36.1%, respectively (HR, 0.19; 95% CI, 0.03-0.65; P = 0.006). ADH1B*1/*1, ALDH2*1/*2 and moderate or heavy alcohol consumption before treatment are independent risk factors of metachronous HNSCC. Since it was shown that temperance decreased the incidences of second and third metachronous HNSCC, advice to discontinue alcohol drinking is necessary.

Experiment on endoscopic balloon dilation for esophageal stenosis after endoscopic submucosal dissection in pigs.

BACKGROUND AND AIM: Endoscopic balloon dilation (EBD) is effective for esophageal stenosis caused by ESD. However, an efficient EBD method has not been established. We, therefore, conducted EBD experiments on porcine esophageal stenosis models. METHODS: Study 1: in dilation models (day 22 after ESD), the thickness of the outer muscle layer (as an index of the extension effect) and the area of muscle fiber bundle necrosis in the inner muscle layer (as an index of thermal damage) were evaluated. Study 2: in restenosis models (day 43 after ESD), the thickness of the fibrous plexus (as an index of restenosis) was evaluated. In total, 12 porcine models were created. RESULTS: Study 1: the thickness of the outer muscle layer was 1243 ± 322 µm in surrounding locations and it was 803 ± 145 µm beneath the laceration (p = 0.005). In cases of muscular layer injury, the area of necrosis was 15,500 ± 10400 µm2 in surrounding locations and it was 40,200 ± 12900 µm2 at the laceration site (p < 0.001). Study 2: the thickness of the fibrous plexus was 1359 ± 196 µm in surrounding locations and it was 1322 ± 136 µm2 in the laceration scar site (p = 0.74). CONCLUSION: Since thermal damage persists until the completion of stenosis, EBD in the initial stage should be carefully performed. An extension effect was observed only at the laceration site and it later returned to a status similar to that of surrounding locations. Additional intervention would be required for preventing restenosis.

Characterization of a TNFR2-Selective Agonistic TNF-α Mutant and Its Derivatives as an Optimal Regulatory T Cell Expander.

Regulatory T cells (Tregs) are a subpopulation of lymphocytes that play a role in suppressing and regulating immune responses. Recently, it was suggested that controlling the functions and activities of Tregs might be applicable to the treatment of human diseases such as autoimmune diseases, organ transplant rejection, and graft-versus-host disease. TNF receptor type 2 (TNFR2) is a target molecule that modulates Treg functions. In this study, we investigated the role of TNFR2 signaling in the differentiation and activation of mouse Tregs. We previously reported the generation of a TNFR2-selective agonist TNF mutant, termed R2agoTNF, by using our unique cytokine modification method based on phage display. R2agoTNF activates cell signaling via mouse TNFR2. In this study, we evaluated the efficacy of R2agoTNF for the proliferation and activation of Tregs in mice. R2agoTNF expanded and activated mouse CD4+CD25+ Tregs ex vivo. The structural optimization of R2agoTNF by internal cross-linking or IgG-Fc fusion selectively and effectively enhanced Treg expansion in vivo. Furthermore, the IgG-Fc fusion protein suppressed skin-contact hypersensitivity reactions in mice. TNFR2 agonists are expected to be new Treg expanders.

Evaluation of Pharyngeal Background Mucosa in Patients with Superficial Hypopharyngeal Carcinoma.

OBJECTIVES/HYPOTHESIS: Transoral surgery (TOS) has become increasingly popular for patients with superficial hypopharyngeal squamous cell carcinoma (SCC). However, the number of patients in whom metachronous multiple SCC of the head and neck (HNSCC) occurs has also increased. In this study, we investigated whether multiple lugol-voiding lesions (LVLs) in the pharyngeal background mucosa observed during TOS would be a biomarker of metachronous HNSCC. STUDY DESIGN: Retrospective study. METHODS: We examined 362 patients who underwent TOS for superficial hypopharyngeal carcinoma. Endoscopic images were reviewed in a blinded fashion by two endoscopists. LVLs in the pharyngeal mucosa were graded as follows: A, no lesions; B, 1 to 4 lesions; and C, ≥5 lesions per endoscopic view. RESULTS: Cumulative incidence curves of secondary HNSCC in the groups of grades A, B, and C revealed 3-year incidence rates of 14.4%, 18.8%, and 29.3%, respectively (P = .001 for A vs. C and P = .002 for B vs. C). Cumulative incidence curves of third HNSCC in the groups of grades A, B. and C revealed 5-year incidence rates of 3.9%, 9.8%, and 19.6%, respectively (P = .001 for A vs. C and P = .006 for B vs. C). Cumulative incidence curves of fourth HNSCC in the groups of grades A, B, and C revealed 7-year incidence rates of 0%, 2.3%, and 13.2%, respectively (P = .025 for A vs. C and P = .009 for B vs. C). CONCLUSIONS: Multiple LVLs in the pharyngeal mucosa increase the risk of development of metachronous multiple HNSCC. LEVEL OF EVIDENCE: 3 (nonrandomized, controlled cohort/follow-up study) Laryngoscope, 131:2036-2040, 2021.

Optical effect of spraying l-menthol on gastric intestinal metaplasia visualized by linked color imaging.

OBJECTIVE: Linked color imaging (LCI) enables noninvasive detection of gastric intestinal metaplasia (GIM) as a lavender color sign (LCS), and there has been a recent report that l-menthol enhanced GIM with LCI. We measured color values of GIM and surrounding mucosa with white light imaging (WLI), LCI and LCI after spraying l-menthol (Mint-LCI) and investigated the effect of l-menthol on gastric mucosa. METHODS: Endoscopic images of the antrum with WLI, LCI and Mint-LCI from 18 patients were prepared. Each of six regions of interest (three points of GIM and three points of surrounding mucosa) was selected for each modality, and CIE1976 (L*a*b*) color space was used to measure the color values. The primary endpoint was color differences (ΔE) between GIM and surrounding mucosa in each modality. RESULTS: For surrounding mucosa, the mean a* value with Mint-LCI was significantly higher than the mean values with WLI and LCI (P < 0.01). The mean b* value of GIM with LCI was significantly lower than that of surrounding mucosa, and spraying l-menthol decreased the b* values of GIM with a change to a deeper lavender color (LCI: 10.0 ± 5.8, Mint-LCI: 3.7 ± 6.1, P < 0.01). However, there was no significant difference in mean ΔE values between LCI and Mint LCI (LCI: 21.1 ± 6.6, Mint-LCI: 22.7 ± 5.4, NS). After spraying l-menthol, the microstructure of GIM changed to translucent and microvessels were obscured. CONCLUSIONS: As shown by LCI, spraying l-menthol optically enhances the color of GIM in the antrum.

Evaluation of the effect of keratinized mucosa on peri-implant tissue health using a multivariate analysis.

PURPOSE: This study investigated the relationship between peri-implant tissue health and the presence of keratinized mucosa (≥ 2 mm) using multivariate analysis. METHODS: A total of 334 dental implants placed in 111 partially edentulous patients (34 males, 77 females) and restored with fixed prostheses were included in this study. The patients were recalled 12-146 months after completion of the prosthodontic treatment. Clinical parameters included modified plaque index (mPI), modified bleeding index (mBI), probing pocket depth (PPD), and radiographic bone loss (BL). The effects of the following potential explanatory variables on these parameters were analyzed: the presence of keratinized mucosa, age, sex, oral hygiene status, history of periodontitis, cigarette smoking, implant site, and time elapsed since prosthesis delivery. Statistical analysis included multivariate ordinal logistic regression and generalized estimating equations. Significance wa s established when two-sided p-values were less than 0.05. RESULTS: The mPI, mBI, and PPD in the presence or absence of keratinized mucosa did not show statistically significant differences. However, the presence of keratinized mucosa was significantly related to BL (odds ratio 4.33, p < 0.01). CONCLUSIONS: The results of our study suggest that the presence of keratinized mucosa is useful for reducing bone resorption and can help to maintain peri-implant tissue health.

Relationships of early esophageal cancer with human papillomavirus and alcohol metabolism.

BACKGROUND: It is well known that an alcohol consumption habit together with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) is an important risk factor for the development of esophageal squamous cell carcinoma (ESCC). It remains controversial whether human papillomavirus (HPV) infection contributes to the occurrence/development of ESCC. There has been no study in which the relationship between ESCC and HPV in addition to alcohol dehydrogenase-1B (ADH1B) and ALDH2 genotypes was evaluated. AIM: To evaluate relationships between HPV infection and development of esophageal cancer, particularly early esophageal cancer, based on ADH1B/ALDH2 polymorphisms. METHODS: We conducted an exploratory retrospective study using new specimens, and we enrolled 145 patients who underwent endoscopic resection for superficial ESCC and had been observed for more than two years by both physical examination and endoscopic examination in Hokkaido University Hospital. Saliva was collected to analyze genetic polymorphisms of ADH1B/ALDH2. We performed in situ hybridization for resected specimens to detect HPV by using an HPV type 16/18 probe. RESULTS: HPV was detected in 15 (10.3%) of the 145 patients with ESCC. HPV-positive rates in inactive ALDH2*1/*2 and ALDH2*1/*1 + *2/*2 were 10.8% and 9.8%, respectively (P = 1.00). HPV-positive rates in slow-metabolizing ADH1B*1/*1 and ADH1B*1/*2 + *2/*2 were 12.0% and 10.0%, respectively (P = 0.72). HPV-positive rates in the heavy or moderate alcohol consumption group and the light or rare consumption group were 11.1% and 8.7%, respectively (P = 0.68). HPV-positive rates in the heavy smoking group and the light or no smoking group were 11.8% and 8.3%, respectively (P = 0.59). The 3-year incidence rates of secondary ESCC or head and neck cancer after initial treatment in the HPV-positive and HPV-negative groups were 14.4% and 21.4% (P = 0.22), respectively. CONCLUSION: In the present situation, HPV status is considered to be less important than other risk factors, such as alcohol consumption, smoking habit, ADH1B/ALDH2 polymorphisms, and HPV status would therefore have no effect on ESCC risk management.

Multivariate analysis of the influence of prosthodontic factors on peri-implant bleeding index and marginal bone level in a molar site: A cross-sectional study.

BACKGROUND: Peri-implant tissue condition can result from prosthodontic, surgical and bacteriological factors. PURPOSE: This study investigated the effects of prosthodontic factors on peri-implant tissue. MATERIALS AND METHODS: Subjects were 140 patients with 310 implants from Osaka University Dental Hospital. Prosthodontic factors examined were the connection type, the suprastructure retention type, the material of the abutment and the mesiodistal and buccolingual prosthetic form of the superstructure as emergence angle. The objective variables were the modified bleeding index (mBI) and marginal bone level (MBL). Statistical analysis was used as a generalized estimation equation. RESULTS: The taper joint had a significantly smaller MBL than the butt joint (P < .001). There was no significant difference in mBI and MBL between cement and screw retaining. Zirconium and titanium resulted in a significantly smaller mBI than gold alloy (zirconium/gold alloy: P = .037, titanium / gold alloy: P = .021), but there was no significant difference in the MBL. Both mBI and MBL tended to be smaller when the emergence angle was around 20° to 40°, although this difference was not significant. CONCLUSION: As a result of multivariate analysis, our findings suggest that to reduce MBL from the perspective of prosthodontic factors it is preferable to use an implant with a taper joint connection positioned with an emergence angle of 20° to 40°.