An unusual presentation of chordoma as a pyloric ring submucosal tumor: The first case report of a primary gastrointestinal lesion in humans.

INTRODUCTION AND IMPORTANCE: Chordomas are rare malignant bone neoplasms that are presumed to arise from chordal remnants in the fetal stage and typically occur along the axial skeleton. The extra-skeletal chordomas reported to date include soft tissue of the extremities and nasopharynx. Chordoma arising from the gastrointestinal wall has not been previously described. CASE PRESENTATION: We report on a 42-year-old man with primary chordoma presenting as a gastroduodenal submucosal tumor centered on the pyloric ring. The patient was consistently asymptomatic, and the tumor was an incidental finding. However, during a follow-up at approximately 1.6 years, an increase in tumor size was identified on computed tomography (CT), and surgical resection was performed without a definite pathologic diagnosis. The patient was successfully treated with distal gastrectomy, and the histological diagnosis was a conventional chordoma. The diagnosis was confirmed via immunohistochemical staining for brachyury, pan-cytokeratin, S-100, and SOX9. Postoperative CT and magnetic resonance imaging revealed no recurrence or metastasis during the 1.5-year follow-up period. CLINICAL DISCUSSION: Primary chordomas of the digestive tract are rare. Embryologic development of the notochord does not explain the existence of remnants in the gastrointestinal wall. Moreover, notochordal remnants, as precursors of chordoma, were not identified in the current case. The gastroduodenal chordoma may not have originated from embryonic notochordal remnants but through aberrant brachyury activation without a notochordal precursor. CONCLUSION: We report the first case of primary gastrointestinal chordoma in humans. The tumor was completely removed surgically, without postoperative recurrence.

Improving the Prognosis of Pancreatic Cancer Through Early Detection: Protocol for a Prospective Observational Study.

BACKGROUND: Pancreatic cancer is associated with high mortality and its rates of detection are very low; as such, the disease is typically diagnosed at an advanced stage. A number of risk factors for pancreatic cancer have been reported and may be used to identify individuals at high risk for the development of this disease. OBJECTIVE: The aim of this prospective, observational trial is to evaluate a scoring metric for systematic early detection of pancreatic cancer in Mie Prefecture, Japan. METHODS: Eligible patients aged 20 years and older will be referred from participating clinics in the Tsu City area to the Faculty of Medicine, Gastroenterology, and Hepatology at Mie University Graduate School, until September 30, 2022. Participants will undergo a detailed examination for pancreatic cancer. Data collection will include diagnostic and follow-up imaging data and disease staging information. RESULTS: The study was initiated in September 2020 and aims to recruit at least 150 patients in a 2-year period. Recruitment of patients is currently still underway. Final data analysis is expected to be complete by March 2025. CONCLUSIONS: This study will provide insights into the feasibility of using a scoring system for the early detection of pancreatic cancer, thus potentially improving the survival outcomes of diagnosed patients. TRIAL REGISTRATION: UMIN-CTR Clinical Trials Registry UMIN000041624; https://tinyurl.com/94tbbn3s. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/26898.

Complete Denture Fabrication Using Digitally Fabricated Copy Dentures for a Patient with Moderate Dementia.

A 91-year-old woman was referred to our hospital with a chief complaint of unsatisfactory fit and pain associated with her complete dentures. She had moderate dementia with difficulty in communication (Mini-Mental State Examination, 16; Barthel Index, 15). The closed impressions and jaw record were taken with the digitally fabricated copy dentures as follows. First, the tissue conditioner was used to correct the poor fit of the old dentures, following which minor occlusal alterations were made. Second, the copy dentures that copied the morphology of the corrected old dentures using three-dimensional (3D) scanner were fabricated with a 3D printer. The new dentures were then fabricated using conventional methods as follows. The impressions were cast and articulated, and the dentures were subsequently processed. This case report documented the following results. First, the acceptance of new dentures appeared to be easier since the new dentures copied the morphology of the familiar dentures digitally. Moreover, the 3D data of the dentures could be used for immediate denture fabrication in case of fracture or loss of the dentures. Second, only two visits were required for taking an impression and delivering the complete dentures. In addition, her old dentures were brought to our dental office by the patient's family after the patient's dinner; immediately after copying the dentures' morphology, the dentures were returned to the patient's family, thus avoiding any disturbance to the patient's eating routine. These reduced the burden on the patient and her family.

Hydrogen generation by reaction of Si nanopowder with neutral water.

Si and its oxide are nonpoisonous materials, and thus, it can be taken for medical effects. We have developed a method of generation of hydrogen by use of reactions of Si nanopowder with water in the neutral pH region. Si nanopowder is fabricated by the simple bead milling method. Si nanopowder reacts with water to generate hydrogen even in cases where pH is set at the neutral region between 7.0 and 8.6. The hydrogen generation rate strongly depends on pH and in the case of pH 8.0, ∼55 ml/g hydrogen which corresponds to that contained in approximately 3 L saturated hydrogen-rich water is generated in 1 h. The reaction rate for hydrogen generation greatly increases with pH, indicating that the reacting species is hydroxide ions. The change of pH after the hydrogen generation reaction is negligibly low compared with that estimated assuming that hydroxide ions are consumed by the reaction. From these results, we conclude the following reaction mechanism: Si nanopowder reacts with hydroxide ions in the rate-determining reaction to form hydrogen molecules, SiO2, and electrons in the conduction band. Then, generated electrons are accepted by water molecules, resulting in production of hydrogen molecules and hydroxide ions. The hydrogen generation rate strongly depends on the crystallite size of Si nanopowder, but not on the size of aggregates of Si nanopowder. The present study shows a possibility to use Si nanopowder for hydrogen generation in the body in order to eliminate hydroxyl radicals which cause various diseases.

[A endoscopic treatment of penetration of the colon by an ingested fish bone].

An 81-year-old woman was admitted complaining of left lower abdominal pain. Computed tomography on admission revealed foreign a body penetrating descending colon and free air. We extracted the foreign body endoscopically. The foreign body was a sharp-edged fish bone. She was treated by conservative medication without complication.

Mouthguards: difference in longitudinal dimensional stability between single- and double-laminated fabrication techniques.

Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single-layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37 degrees C water bath for 60 h, equivalent to the time period of 3-months inter-oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J-12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite-element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single-layer MGs in the anterior area (P < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single-layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process.

A method for fabricating an occlusal splint for a patient with limited mouth opening.

This article describes the fabrication of an occlusal splint for a patient with limited mouth opening due to temporomandibular disorder. A face-bow fork is used as a tray to obtain an accurate dual-arch impression and occlusal registration.

Somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease.

We report a case of somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease (VRD). A 64-year-old woman who had had recurrent attacks of acute pancreatitis and cholangitis was found, on gastroduodenal endoscopy, to have a tumor of the papilla of Vater and multiple submucosal tumors of the stomach and duodenum. Numerous submucosal tumors were observed in the stomach, duodenum, and jejunum, and total excision of the papilla of Vater and resection of the duodenal and jejunal submucosal tumors was performed. The tumor of the papilla of Vater showed the histologic appearance of a dense proliferation of tumor cells in acinar form, from the duodenal mucosa to the muscle layer, and psammoma bodies were revealed within the tumor. Immunohistologically, the tumor cells were intensely positive for somatostatin. The submucosal tumors of the duodenum and jejunum were negative for smooth muscle actin, s-100, and neuron-specific enolase (NSE), and positive for CD34 and c-kit, and they were diagnosed as gastrointestinal stromal tumors (GISTs) according to the strict definition. The only 25 cases of papilla of Vater somatostatinoma associated with VRD to have been reported in the English-language literature since 1982 are reviewed, as well as our own case.

Inhibitory effect of loxiglumide (CR 1505), a cholecystokinin receptor antagonist, on N-nitrosobis(2-oxopropyl) amine-induced biliary carcinogenesis in Syrian hamsters.

We evaluated the cholecystokinin (CCK) receptor antagonist loxiglumide (CR1505) for a possible inhibitory effect on biliary carcinogenesis in a hamster model. Experimental group I underwent cholecystoduodenostomy and ligation of the distal end of the common bile duct, after which the animals were injected with N-nitrosobis(2-oxopropyl)amine (BOP) alone. Group II, after the same surgical procedure as in group I, were given injections of BOP and then given loxiglumide in their diet. The sham-operated group underwent simple laparotomy and then were given injections of BOP. Loxiglumide significantly inhibited BOP carcinogenicity in the gallbladder and extrahepatic bile duct but not in the intrahepatic bile ducts or pancreas. Autoradiography showed that loxiglumide significantly suppressed (125)I-Bolton-Hanter (BH)-CCK-8 binding to CCK receptors in the gallbladder and extrahepatic bile duct but not in the liver or pancreas, and CCK binding to its receptors was observed in an area identified as cancer tissue. CCK receptor antagonists have an inhibitory effect on BOP carcinogenesis in the extrahepatic biliary tract, including the gallbladder and extrahepatic bile duct, of Syrian hamsters. The difference in the inhibitory effect of loxiglumide on biliary carcinogenesis in hamsters according to site may be due to differences in CCK receptors or the affinity of loxiglumide for such biliary tract organs. A difference between carcinogenesis in the intrahepatic bile ducts and extrahepatic biliary tract may be another reason.