1.Possible Involvement of p38 MAP Kinase in Retinoid-stimulated Expression of Indian Hedgehog in Prehypertrophic Chondrocytes
Tsuyoshi Shimo ; Eiki Koyama ; Soichiro Ibaragi ; Naito Kurio ; Daisuke Yamamoto ; Tatsuo Okui ; Koji Kishimoto ; Hiroshi Mese ; Akira Sasaki
Oral Science International 2008;5(1):1-14
The mandibular condyle formation during temporomandibular joint (TMJ) development exhibits endochondral bone formation, and the elongation process is dependent on the normal cartilage proliferation and differentiation. Retinoids are important for maturation of growth-plate chondrocytes, but the identity of their downstream effectors remains unclear. In this study, we carried out a series of studies at the cellular, biochemical, and molecular levels to determine whether, and if so how, retinoid signaling is related to the expression and function of Indian hedgehog (Ihh) in chondrocyte proliferation. First we analyzed the RA receptor (RAR) and Ihh expression pattern in E18 mandibular condyle. RARα and RARβ mRNA were characterized in the perichondrium around the condyle, whereas RARγ mRNA was expressed in the immature and prehypertrophic chondrocytes and the expression was overlapped with Ihh gene expression. Next we established a high-density culture model of chick cephalic chondrocytes in the prehypertrophic stage. We found that all-trans retinoic acid (RA) induced Ihh mRNA gene expression in this system. The RA pan-antagonist Ro 41-5253 inhibited both endogenous and RA-induced Ihh mRNA in a dose-dependent manner. The Ihh mRNA expression induced by RA required de novo protein synthesis, and was mediated by RARγ. Immunoblots showed that the prehypertrophic chondrocytes contained sizable levels of phosphorylated p38 mitogen-activated protein (MAP) kinase that were time- and dose-dependently increased by the RA treatment. Experimental p38 inhibition led to a severe drop in baseline and RA-stimulated Ihh expression. Exogenous recombinant Ihh stimulated the proliferation of proliferating chondrocytes, whereas RA inhibited the proliferation of these chondrocytes through p38 MAPK. Retinoids appear to play a primary role in controlling both the expression and function of Ihh in prehypertrophic chondrocytes and do so via p38 MAP kinase.
2.Peroral Pancreatoscopy with Videoscopy and Narrow-Band Imaging in Intraductal Papillary Mucinous Neoplasms with Dilatation of the Main Pancreatic Duct
Yui KISHIMOTO ; Naoki OKANO ; Ken ITO ; Kensuke TAKUMA ; Seiichi HARA ; Susumu IWASAKI ; Kensuke YOSHIMOTO ; Yuuto YMADA ; Koji WATANABE ; Yuusuke KIMURA ; Hiroki NAKAGAWA ; Yoshinori IGARASHI
Clinical Endoscopy 2022;55(2):270-278
Background/Aims:
Endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMNs) is useful in determining whether the lesions are benign or malignant. This study aimed to examine the usefulness of peroral pancreatoscopy (POPS) in determining the prognosis of IPMNs.
Methods:
POPS with videoscopy was performed using the mother–baby scope technique. After surgery, computed tomography/magnetic resonance cholangiopancreatography or ultrasonography and blood tests were performed every 6 months during the follow-up.
Results:
A total of 39 patients with main pancreatic duct (MPD)–type IPMNs underwent POPS using a videoscope, and the protrusions in the MPD were observed in 36 patients. The sensitivity and specificity of cytology/biopsy performed at the time of POPS were 85% and 87.5%, respectively. Of 19 patients who underwent surgery, 18 (95%) patients had negative surgical margins and 1 (5%) patient had a positive margin.
Conclusions
In IPMNs with dilatation of the MPD, POPS is considered effective if the lesions can be directly observed. The diagnosis of benign and malignant lesions is possible depending on the degree of lesion elevation. However, in some cases, slightly elevated lesions may increase in size during the follow-up or multiple lesions may be simultaneously present; therefore, careful follow-up is necessary.
3.Peroral pancreatoscopy with videoscopy and narrow-band imaging in intraductal papillary mucinous neoplasms with dilatation of the main pancreatic duct
Yui KISHIMOTO ; Naoki OKANO ; Ken ITO ; Kensuke TAKUMA ; Seiichi HARA ; Susumu IWASAKI ; Kensuke YOSHIMOTO ; Yuto YAMADA ; Koji WATANABE ; Yusuke KIMURA ; Hiroki NAKAGAWA ; Yoshinori IGARASHI
Clinical Endoscopy 2023;56(2):261-261
4.Are Newer Extracorporeal Shock Wave Lithotripsy Models Truly Improving Pancreatolithiasis Lithotripsy Performance? A Japanese Single-Center Study Using Endoscopic Adjunctive Treatment
Ken ITO ; Naoki OKANO ; Kensuke TAKUMA ; Susumu IWASAKI ; Koji WATANABE ; Yusuke KIMURA ; Yuto YAMADA ; Kensuke YOSHIMOTO ; Seiichi HARA ; Yui KISHIMOTO ; Takahisa MATSUDA ; Yoshinori IGARASHI
Gut and Liver 2023;17(4):647-658
Background/Aims:
Many Japanese institutions use electromagnetic extracorporeal shock wave lithotripsy (ESWL) systems for treating pancreatic duct stones. However, there are no reports on direct comparisons between recent electromagnetic lithotripters. This study aimed to verify whether the new electromagnetic lithotripter can improve the efficiency of pancreatic stone fragmentation, and to clarify the role of combined endoscopic treatment on the clearance of pancreatic duct stones.
Methods:
We retrospectively identified 208 patients with pancreatolithiasis who underwent endoscopic adjunctive treatment after pancreatic ESWL at a single Japanese center over a 17-year period. We evaluated the outcome data of this procedure performed with SLX-F2 (last 2 years; group A) and Lithostar/Lithoskop (first 15 years; group B), as well as additional endoscopic treatments for pancreatolithiasis. We also performed logistic regression analysis to detect various factors associated with the procedure.
Results:
For pancreatic head stones, ESWL disintegration was achieved in 93.7% of group A patients and 69.0% of group B patients (p=0.004), and adjunctive endoscopic treatment removed stones in 96.8% of group A patients and 73.0% of group B patients (p=0.003). Multivariate analysis revealed that lithotripter type (odds ratio, 6.99; 95% confidence interval, 1.56 to 31.33; p<0.01) and main pancreatic duct stricture (odds ratio, 2.87; 95% confidence interval, 1.27 to 6.45; p<0.01) were significant factors for ESWL fragmentation.
Conclusions
The SLX F2 showed high performance in fragmenting the pancreatic duct stones.In addition, endoscopic adjunctive treatment improved the overall success rate of the procedure. The improved ESWL lithotripter has many advantages for patients undergoing pancreatic lithotripsy treatment.
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