A Comparison of the Efficacy of Plastic Stent Placement Above and Across the Sphincter of Oddi for Benign Biliary Hilar Stricture.

We investigated the efficacy and safety of endoscopic plastic stent (PS) placement for hilar benign biliary strictures (BBSs) and compared cases with PS placement above (inside stent, IS) and across (usual stent, US) the sphincter of Oddi. Patients who underwent initial endoscopic PS placement for hilar BBSs between August 2012 and December 2021 were retrospectively analyzed. Hilar BBSs in 88 patients were investigated. Clinical success was achieved in 81 of these cases (92.0%), including 38 patients in the IS group and 43 patients in the US group. Unexpected stent exchange (uSE) before the first scheduled PS exchange occurred in 18 cases (22.2%). The median time from first stent placement to uSE was 35 days. There was no significant difference in the rate and median time to uSE between the two groups. The rates of adverse events such as pancreatitis or cholangitis in the two groups did not significantly differ. However, the rate of difficult stent removal in the IS group (15.8%) was significantly higher than that in the US group (0%) (p=0.0019). US placement is preferable to IS placement for scheduled stent exchange, as it offers the same effectiveness and risk of adverse events with easier stent removal.

Usefulness of a newly designed plastic stent for endoscopic re-intervention in patients with malignant hilar biliary obstruction.

Background and study aims We designed a new 7-Fr plastic stent for treating self-expandable metal stent (SEMS) obstruction in patients with malignant hilar biliary obstruction (MHBO) via endoscopic re-intervention with the stent-in-stent (SIS) method and evaluated its efficacy. Patients and methods A total of 33 consecutive patients who underwent endoscopic re-intervention for metal stent obstruction after multi-branched SEMS placement were enrolled. The initial SEMSs were placed in two or three biliary branches in 14 and 19 patients, respectively. We retrospectively evaluated the technical and clinical success, and adverse events. Technical success was defined as successful plastic stent placement into all target branches through the lumen of the SEMS. Results The technical success rates were 85.7 % (12/14) and 78.9 % (15/19) in patients who underwent two- or three-branched biliary drainage, respectively. The clinical success rate was 100 % in the 27 patients in whom technical success was achieved. We achieved successful plastic stent placement in more than two branches, using the new plastic stent combined with a conventional plastic stent, in 97.0 % (32/33). Conclusions This new plastic stent was technically feasible for treating stent obstruction via re-intervention with SIS methods.

Effects of low crystalline carbonate apatite on proliferation and osteoblastic differentiation of human bone marrow cells.

Carbonated apatite (CO3Ap) is the inorganic component of bone. We have proposed a new method for the fabrication of CO3Ap blocks based on a dissolution-precipitation method using a synthetic precursor. The aim of this study is to examine the effects of low crystalline CO3Ap on initial cell attachment, proliferation and osteoblastic differentiation of human bone marrow cells (hBMCs) using sintered hydroxyapatite and tissue culture plates as controls. Initial cell attachment and proliferation were assessed with a MTT assay. Expression of osteoblastic markers was examined by reverse transcription-polymerase chain reaction. XRD and FT-IR results showed formation of B-type carbonate apatite with lower crystallinity. No difference was observed for initial cell attachment between HAp and CO3Ap discs. hBMSC attached more significantly on tissue culture plate than on HAp and CO3Ap discs. The number of cells on HAp was higher than that on CO3Ap until day 7, after which the number of cells was similar. hBMSC proliferated more significantly on tissue culture plate than on HAp and CO3Ap discs. In contrast, hBMCs incubated on CO3Ap demonstrated much higher expression of osteoblastic markers of differentiation, such as type I collagen, alkaline phosphatase, osteopontin and osteocalcin, than hBMCs on HAp. On the tissue culture plate, they were not any change throughout the culture period. These results demonstrated that low crystalline CO3Ap exhibit higher osteoinductivity than HAp.

Prevalence and imaging characteristics of palatine tonsilloliths detected by CT in 2,873 consecutive patients.

AIM: Tonsilloliths are calcified structures that develop in tonsillar crypts. They are commonly detected in daily clinical practice. The prevalence of tonsilloliths was 16 to 24% in previous reports, but it is inconsistent with clinical experience. The aim of this study is to clarify the prevalence, number, and size distribution of tonsilloliths using computed tomography (CT) in a relatively large number of patients. MATERIALS AND METHODS: We retrospectively reviewed the scans of 2,873 patients referred for CT examinations with regard to tonsilloliths. RESULTS: Palatine tonsilloliths were found in 1,145 out of 2,873 patients (39.9%). The prevalence of tonsilloliths increased with age, and most commonly in patients of ages 50-69. The prevalence in the 30s and younger was statistically lower than in the 40s and older (P < 0.05). The number of tonsilloliths per palatine tonsil ranged from one to 18. The size of the tonsilloliths ranged from 1 to 10 mm. For the patients with multiple CT examinations,the number of tonsilloliths increased in 51 (3.9%) and decreased in 84 (6.5%) of the tonsils. CONCLUSIONS: As palatine tonsilloliths are common conditions, screenings for tonsilloliths during the diagnosis of soft tissue calcifications should be included in routine diagnostic imaging.

Whole Exome Sequencing of SMO, BRAF, PTCH1 and GNAS in Odontogenic Diseases.

BACKGROUND/AIM: Odontogenic diseases are diagnosed based on clinical course, imaging, and histopathology. However, a definitive diagnosis is not always possible. PATIENTS AND METHODS: We analyzed whole exons of SMO, BRAF, PTCH1 and GNAS using next-generation sequencing (NGS) in 18 patients. RESULTS: Of the 6 patients with ameloblastoma, 2 patients had the same missense mutation in BRAF, and 1 patient with peripheral ameloblastoma had a missense mutation in PTCH1. Of the 7 patients with odontogenic keratocyst, 4 patients had a missense mutation in PTCH1, 2 patients had missense mutations in BRAF, and 1 patient had a missense mutation in SMO. The patient with odontoma had missense mutations in SMO, BRAF and PTCH1. One patient with cement-osseous dysplasia had missense mutations in SMO and PTCH1. The patient with adenomatoid odontogenic tumor had missense mutations in SMO. CONCLUSION: Whole exome sequencing of the above genes by NGS would be useful for the differential diagnosis of odontogenic diseases.

miR­1246 and miR­4644 in salivary exosome as potential biomarkers for pancreatobiliary tract cancer.

Pancreatobiliary tract cancer is a highly fatal cancer. Detection of pancreatobiliary tract cancer is difficult because it lacks typical clinical symptoms and because of its anatomical location. Biomarker discovery is therefore important to detect pancreatobiliary tract cancer in its early stage. A study demonstrated that expression levels of miR­1246, miR­3976, miR­4306, and miR­4644 in serum exosomes were higher in pancreatic cancer patients than these levels in healthy control participants. Supposing that microRNA (miRNA) expression profiles in saliva are similar to those in serum, four miRNAs (miR­1246, miR­3976, miR­4306, and miR­4644) in salivary exosomes may also be useful for detection of pancreatobiliary tract cancer. In this study, it was examined whether these miRNAs could be used as biomarkers for pancreatobiliary tract cancer. Twelve pancreatobiliary tract cancer patients and 13 healthy control participants were analyzed as a cancer and a control group, respectively. Unstimulated whole saliva was collected, salivary exosomes were isolated, and total RNA was extracted. Using quantitative real­time PCR (RT­qPCR), the relative expression ratios of miR­1246 and miR­4644 were significantly higher in the cancer group than these ratios in the control group. Receiver operating characteristic (ROC) curves were constructed to analyze the discrimination power of these miRNAs. For miR­1246, the results yielded an area under the curve (AUC) of 0.814 (P=0.008). For miR­4644, the results yielded an AUC of 0.763 (P=0.026). For the combination of miR­1246 and miR­4644, the results yielded an increased AUC of 0.833 (P=0.005). This pilot study suggests that miR­1246 and miR­4644 in salivary exosomes could be candidate biomarkers for pancreatobiliary tract cancer.

Possible role of stromal-cell-derived factor-1/CXCR4 signaling on lymph node metastasis of oral squamous cell carcinoma.

We examined the role of chemokine signaling on the lymph node metastasis of oral squamous cell carcinoma (SCC) using lymph node metastatic (HNt and B88) and nonmetastatic oral SCC cells. Of 13 kinds of chemokine receptors examined, only CXCR4 expression was up-regulated in HNt and B88 cells. CXCR4 ligand, stromal-cell-derived factor-1alpha (SDF-1alpha; CXCL12), induced characteristic calcium fluxes and chemotaxis only in CXCR4-expressing cells. CXCR4 expression in metastatic cancer tissue was significantly higher than that in nonmetastatic cancer tissue or normal gingiva. Although SDF-1alpha was undetectable in either oral SCC or normal epithelial cells, submandibular lymph nodes expressed the SDF-1alpha protein, mainly in the stromal cells, but occasionally in metastatic cancer cells. The conditioned medium from lymphatic stromal cells promoted the chemotaxis of B88 cells, which was blocked by the CXCR4 neutralization. SDF-1alpha rapidly activated extracellular signal-regulated kinase (ERK)1/2 and Akt/protein kinase B (PKB), and their synthetic inhibitors attenuated the chemotaxis by SDF-1alpha. SDF-1alpha also activated Src family kinases (SFKs), and its inhibitor PP1 diminished the SDF-1alpha-induced chemotaxis and activation of both ERK1/2 and Akt/PKB. These results indicate that SDF-1/CXCR4 signaling may be involved in the establishment of lymph node metastasis in oral SCC via activation of both ERK1/2 and Akt/PKB induced by SFKs.