Internal structures of a subaerial dacite cryptodome at Usu volcano, Hokkaido, Japan

A partly eroded, subaerial, dacite cryptodome at Showa-Shinzan, Usu volcano, Hokkaido, Japan, displays its internal structures, and provides an excellent opportunity to study contact relationship between cryptodome and overlying sediment. The margin of the cryptodome comprises two facies: inner coherent dacite and outer dacite breccia. The coherent dacite facies is ~5 m in the exposed section, and consists of homogeneous or weakly flow-banded, feldspar-phyric dacite. The dacite breccia facies envelope the coherent dacite facies, and is 4-5 m thick. The breccia is monomictic, non-stratified and consists of angular dacite clasts up to 15 cm across in a cogenetic matrix. The overlying sediment directly covers the dacite breccia facies, and comprises reddish-brown, fluvial deposit. The dacite breccia formed by　fracturing of coherent dacite in response to cooling contraction, and shearing of the fractured dacite due to movement of the growing cryptodome.特集 : 「2003年度実施の地域との共同研究の報告

Peyer’s Patches in the Terminal Ileum in Ulcerative Colitis: Magnifying Endoscopic Findings

Peyer’s patches (PPs), a major component of the gut-associated lymphoid tissue, serve as important antigen entry sites in mucosal immunity. PPs may play a role in the extension of ulcerative colitis (UC) into the terminal ileum. We sought to clarify the magnified endoscopic findings of the PPs in the terminal ileum of UC patients. Eighteen UC patients underwent magnifying chromoendoscopy before initial treatment to evaluate the follicle-associated epithelium (FAE) on the PPs domes and the surrounding villi. In 8 UC patients, as in healthy controls, the PPs’ domes were slightly elevated, covered with the regular FAE lining, and surrounded by dense and bulky villi; however, in 10 UC patients, the PPs’ domes were irregular, and the surrounding villi were sparse and atrophic. These abnormal findings within the PPs were associated with minimal mucosal lesions but not with backwash ileitis; both electron microscopy and magnifying endoscopy confirmed that these lesions were reversible following remission with prednisolone-mesalazine therapy. Similar to Crohn’s disease patients, UC patients commonly had abnormalities in the FAE on PPs’ domes and the surrounding villi on magnifying endoscopy

Gastric Acid Secretion of Rats with Alterative Autonomic Nervous System

The role of the autonomic nervous system in the generation mechanism of gastric stress ulcers has long been attracting attention. We have been investigating the ulcer formation in the spontaneously hypertensive rat (SHR) thought to have a functionally facilitated sympathetic nervous system and in the MGS rat in which the function of the sympathetic nervous system may be attenuated. In the present study, we studied the state of gastric acid secretion under a pyloric ligation condition in these rat species, using WKY rats as the control. The pylorus was ligated for 4 hrs, and the volume and pH of gastric juice and the volume of gastric acid secreted were measured. Both SHRs and MSG rats showed higher pH values and smaller volume of secreted acid than WKY rats. Ulcer formation in SHRs was milder than in control rats as reported previously, and this was thought to be related to the high pH value and the low gastric acid secretion observed in the present study. Although ulcer formation in MSG rats was more frequent than in control animals, factors such as mucosal blood flow etc. were suggested to be rather responsible because of the high pH value and low acid secretion in this species

AN AUTOPSY CASE OF PARATHYROID CARCINOMA

A case of hyperfunctioning parathyroid carcinoma was found in a 78-year-old female who had suffered from hypercalcemia for 5 years. She died of renal failure and pulmonary edema. Autopsy revealed an encapsulated tumor arising from the left upper parathyroid gland. Histologically, fibrous trabeculae, capsular invasion and blood vessel invasion were occasionally present in this tumor, suggesting that this tumor was malignant. However, mitotic figures were rarely observed. We reviewed reported cases of parathyroid carcinoma and discussed about the significance of mitosis for diagnosis

Morphometrical Study on the Sclerotic Inferior Vena Cava in Chronic Lung Disease

The purpose of this study is to determine the relationship between chronic lung disease (CLD) and morphological changes in the inferior vena cava (IVC) from postmortem materials. The IVC and pulmonary truncus were obtained from 70 cases with CLD and/or cor pulmonale and from 23 controls. The tissues were processed for light and electron microscopic studies. The adventitia was by far the thickest component of the IVC wall. The total wall, intimal, and adventitial thicknesses were all significantly greater in the CLD cases than in the controls (p<0.001), but there was no significant difference in the ratio of adventitia thickness to wall thickness. The incidence of intimal thickening was 13.0% and 37.3% in controls and in CLD respectively. Electron microscopic examination of the IVC from the CLD cases revealeda marked increase in the amount of extracellular matrix including collagen, elastic fibers and ground substances in the adventitia as compared with the controls. No foam cells were detected in the thickened intima of the IVC. PA, right ventricular thickness and RV/LV ratio were greater in CLD than in controls. The blood gas levels of the CLD cases indicated obvious hypoxia (PaO2 54.2 mmHg). This study suggests that increased venous pressure and hypoxia might be implicated in the pathogenesis of phlebosclerosis in patients with CLD

Role of Parathyroid Hormone/Parathyroid Hormone-Related Peptide on Cell Proliferation in the Gastric Mucosa

Parathyroid hormone-related peptide (PTHrP) is widely expressed in normal tissues and elicits various functions through the PTH/PTHrP receptor. Relaxation effects of PTHrP on gastrointestinal smooth muscle cells were well documented, but the physiological role on mucosal growth and differentiation is little known. The purpose of this study was to evaluate the expression of PTHrP and PTHPTHrP receptor in the rat gastric mucosa, and the role of PTHrP on mucosal cell proliferation. Male Wistar rats were used in this study. Localization of PTHrP and PTH/PTHrP receptor were observed by immunohistochemistry and in situ hybridization. Expression of PTH/PTHrP receptor mRNA were examined by RNase protection assay in control and stress condition. Double staining with BrDU incorporation was performed to differentiate cell cycle states. Cell proliferative effect by external PTHrP-(1-34) was evaluated by BrDU incorporation. PTHrP immunopositive cells were encountered in and around the mucosal neck area. PTH/PTHrP receptor immunoreactivity was observed in the gastric mucosa broadly. Cells with stronger expression for PTHrP and its cognate receptor were located in the vicinity of generative zone. But BrDU incorporating cells were negative for both PTHrP and PTH/PTHrP receptor. By RNase protection assay, PTH/PTHrP receptor mRNA expression was weak in a steady state, and the receptor expression increased at stress. External PTHrP-(1-34) did not show cell proliferative effect in a steady state. At stress BrDU incorporation was suppressed significantly, and PTHrP-(1-34) increased BrDU incorporation. These observations suggest that PTHrP and PTH/PTHrP receptor involve maintenance of mucosal growth and differentiation in the stomach

Hepatopulmonary syndrome-discussion of cardiopulmonary parameters

We report a 70-year-old man with hepatopulmonary syndrome (HPS) in C liver cirrhosis. Hypoxemia worsened markedly, especially on exertion, while the hepatic function was clinically stable. Contrast echocardiography, 99mTc macroaggregated albumin (99mTcMAA) lung scan, and pulmonary angiography were performed. The findings suggested the presence of both intrapulmonary vascular dilatation and substantial right-to-left shunt. The contribution of intrapulmonary vascular abnormalities in patients with severe liver cirrhosis without abnormal chest radiography and spirometry tests when marked hypoxemia is present should be investigated

Detection of Epstein-Barr Virus and Helicobacter pylori in Primary Malignant Gastric Lymphomas

We studied five patients diagnosed with primary gastric lymphoma between 1985 and 1995 in Omura Munisipa Hospital to investigate the relationship between Helicobacter pylori, Epstein-Barr virus and primary malignant gastric lymphoma. H. pylori was detected by hematoxylin-eosin stain, Giemsa stain, immunohistochemistry while EBV was detected by in situ hybridization in the lymphoma and background mucosa. H. pylori but not EBV, was detected in all cases. Furthermore, malignant lymphomas were mainly located in the area of the fundic gland where H. pylori was frequently identified and caused inflammation. In contrast, malignant lymphomas were not detected in areas with intestinal metaplasia. Our results suggest that malignant lymphoma may develop in a region where the immune system has been activated by H. pylori. In contrast, EBV is unlikely to play an important role in the development of gastric lymphoma, compared to H. pylori