Search PubMed⌕ Search

Biomedical subjects

Y Hosoda

Publications and source records attributed to Y Hosoda.

At least 91 records · Page 5Linked to original sources
PubMed1997

Expression of interstitial collagenase (matrix metalloproteinase-1) in gastric cancers.

The expression of matrix metalloproteinase-1 (MMP-1) gene and the presence of MMP-1 protein in gastric cancer were examined by in situ hybridization and immunohistochemistry. Expression of the interstitial collagenase (MMP-1) gene was detected within the stroma of the neoplastic glands, and infiltration of eosinophils was observed to be associated with regions of MMP-1 gene expression. The degree of eosinophilic infiltration correlated with the level of MMP-1 mRNA expression. Immunostaining showed localization of MMP-1 protein in the stromal cells, and additionally in the neoplastic glands. These findings indicate that the stromal cells may play an important role in the expression of MMP-1, and suggest a pathophysiological role for MMP-1 in the invasion and metastasis of gastric cancer.

Adenocarcinoma↗
PubMed1997

Malignant fibrous histiocytoma of the cecum: report of a case and review of the literature.

Malignant fibrous histiocytoma (MFH) of the gastrointestinal tract is extremely rare. Here we report a case of MFH of the cecum and review other cases of large bowel MFH in the literature. A 64-year-old man had a large tumor mass in the cecum associated with multiple small peritoneal implants. Histologically, most of the lesion showed inflammatory pseudotumor-like appearance; that is, a mixed proliferation of fibroblasts and myofibroblasts loosely arranged in sweeping fascicles or whorled structures and an admixture of chronic inflammatory cell infiltrate. The myofibroblastic nature of the spindle-shaped cells was confirmed by their immunohistochemical and ultrastructural findings. In addition, there was atypical histiocytic cells infiltrate in some areas and marked lymphatic involvement and lymph node metastasis by such histiocytic cells. These features were interpreted as MFH, although it had to be distinguished from inflammatory fibrosarcoma and leiomyosarcoma. The differential diagnosis is discussed here.

Actins↗
PubMed1997

Long-term effects of water-soluble corn bran hemicellulose on glucose tolerance in obese and non-obese patients: improved insulin sensitivity and glucose metabolism in obese subjects.

We examined the effect of soluble corn bran hemicellulose (CBH, 10 g/day) on glucose control and serum insulin in three groups: patients with impaired glucose tolerance (IGT) with (20 subjects) or without (8 subjects) obesity and with healthy non-obese controls (10 subjects). Long-term supplementation (6 months) with CBH decreased the post oGTT curve for patients with impaired mild Type II diabetes, but not that for the controls. Hemoglobin A1c decreased significantly during CBH supplementation in the obese patients, while the fasting glucose level decreased in all three groups, although not significantly. A decreased serum insulin response by oGTT was found in those patients with IGT. The improved oGTT result was associated with improved insulin release and perhaps with peripheral insulin sensitivity. These findings suggest that CBH at a low dose might contribute to glycemic control and would play a useful role in treating Type II diabetes patients.

Adult↗
PubMed1997

Differentiating agent, hexamethylene bisacetamide, inhibits neointimal formation after vascular injury.

BACKGROUND: Hexamethylene bisacetamide (HMBA), a potent differentiating agent of transformed cell lines, has been reported to affect phenotypic modulation and suppress proliferation of vascular smooth muscle cells (VSMCs). The effects of HMBA on the growth of VSMCs were studied in the rat carotid injury model. METHODS: HMBA was added to culture medium of VSMCs explanted from aorta of Sprague Dawley rats and the cell number was counted after 5 days of incubation. The carotid artery of Sprague Dawley rats was denuded with a balloon embolectomy catheter. The rats were treated with continuous infusion of HMBA (1 g/day) or saline for 7 days after injury. RESULTS: HMBA inhibited VSMC proliferation in a dose-dependent manner (at a HMBA concentration of 1-5 mM). Plasma concentration of HMBA during continuous infusion was in the range 0.8-1.0 mM. Immunohistochemistry of proliferating cell nuclear antigen showed that HMBA inhibited VSMC proliferation after vascular injury. Cell number in the intima and neointimal thickening were significantly reduced in HMBA-treated rats at 14 days after injury. CONCLUSIONS: Systemic administration of HMBA inhibited VSMC proliferation in the rat carotid injury model.

Acetamides↗
PubMed1997

[Concealed infective endocarditis].

The occurrence of concealed infection or "natural remission" in infective endocarditis was investigated microscopically in 35 consecutive patients (36 valves) with infective endocarditis (between April 1987 and May 1995). Four patients were considered as having concealed or silent infective endocarditis. Preoperative diagnosis of these patients was mitral valve prolapse, rheumatic aortic valve stenosis with insufficiency, aortic valve prolapse and hypertrophic cardiomyopathy, respectively. These patients did not present with any clinical signs of infective endocarditis such as cardiac murmur and ventricular dysfunction. Histological examination of the excised valves revealed valvular perforation, small round cell infiltration, neovascularization, remnants of vascular smooth muscle cells, and organizing vegetations. These findings are consistent with the histological findings of infective endocarditis. Latent infective endocarditis may be present without inflammatory manifestation.

Aortic Valve Insufficiency↗
PubMed1997

[Descending necrotizing mediastinitis secondary to retropharyngeal abscess--a case report].

A 69-year-old man complained of a sore throat, neck swelling, and disturbance of swallowing with dyspnea. He underwent tracheostomy and cervical drainage. The plain chest roentgenogram and CT scans suggested mediastinitis, so he was transferred to our hospital. Cultures revealed a mixed aerobic and anaerobic infection. On hospital day 2, the neck was explored and pus was found in the connective tissue. Despite drainage and intravenous panipenem with betamipron and clindamycin, he remained febrile and a mediastinal abscess was seen on repeat CT. On hospital day 10, reexploration of the mediastinum was done through cervical and right thoracotomy incisions. A large amount of pus was drained from the posterior mediastinum and its necrotic tissue was debrided. Myocardial infarction occurred intraoperatively, but the patient was successfully resuscitated. Following this procedure, the patient's condition and radiologic findings gradually improved. Cultures of the drain fluid became negative, and he was discharged on hospital day 103. In conclusion, both transcervical drainage and aggressive mediastinal exploration via thoracotomy are essential to salvage a patient with descending necrotizing mediastinitis. CT scanning is useful for early diagnosis of mediastinitis and for follow up.

Aged↗
PubMed1996

The vasculature of the peripheral portion of the human eighth cranial nerve.

The vasculature of the peripheral portion of the human eighth cranial nerve (VIIIN) was investigated by light and transmission electron microscopy. Arterioles and venules running longitudinally around the VIIIN formed the extrinsic vascular system. The anatomical relationship between these extrinsic vessels and the VIIIN sheath was similar to that between blood vessels on the surface of the brain and the pia mater. In the endoneurium, postcapillary venules and large capillaries were sparsely distributed and longitudinally arranged, and these microvessels formed the intrinsic microvascular system, which was supported by the extrinsic vascular system via anastomosing vessels. The ultrastructural features of the internal auditory artery and its main branches were the same as those of other intracranial arteries. Ultrastructural study also revealed myo-endothelial junctions in anastomosing arterioles, and endothelio-pericytic junctions in extrinsic and anastomosing venules. Microvascular endothelial cells were connected by tight junctions in both the vestibular ganglion and the rest of the VIIIN. These features of the vasculature were considered to be effective for maintenance of the endoneurial fluid and regulation of the circulation in the peripheral portion of the human VIIIN.

Adolescent↗
PubMed1996

Ultrastructural recognition of gap junctions between melanocytes in human vestibular organs by tannic acid containing fixative preparation and freeze-fracture technique.

BACKGROUND: The purpose of the present study was to obtain additional information about the ultrastructural characteristics of gap junctions between melanocytes in human vestibular organs by using various ultrastructural techniques. METHODS: All materials were obtained from patients with vestibular schwannoma. Glutaraldehyde-fixed specimens and specimens treated with fixative containing glutaraldehyde and tannic acid were processed for conventional ultrathin transmission electron microscopic (TEM) examination. Others were prepared for freeze-fracture replica and examined by TEM. RESULTS: Gap junctions were present between adjacent subepithelial melanocytes. The gaps between the inner leaflets of the apposed plasma membranes at the gap junctions were 10-12 nm, and the gaps between the outer leaflets were 2-4 nm. The intercellular space between the apposed plasma membranes of gap junctions showed the deposition of high electron-dense material in specimens prepared with fixative containing glutaraldehyde and tannic acid. At the highest magnification specimens fixed by glutaraldehyde with or without tannic acid and cut obliquely to the plasma membranes showed periodic substructures with constant repeating lattices or a small porous structure at the junctions. Study by freeze fracture revealed that these gap junctions between melanocytes consisted of 100-200 aggregations of connexon particles that were approximately 8.8 nm in diameter. CONCLUSIONS: We suggest that melanocytes may construct a cellular network involved in the maintenance of the homeostasis of human vestibular organs through the intimate transmission of various signals or intercellular informations via well-developed gap junctions.

Adult↗
PubMed1996

Preferential activation of CD4+V beta 5.2/5.3+ intestinal intraepithelial lymphocytes in the inflamed lesions of Crohn's disease.

To analyze the nature of intestinal intraepithelial lymphocytes (iIELs) in inflammatory intestinal disease, we established T cell lines of iIELs isolated from endoscopic biopsied ileal and colonic mucosa of Crohn's disease patients. Seven T cell lines from the inflamed terminal ileum of 13 patients, but none of 16 T cell lines from normal terminal ileum, have shown a deviation of T cell receptor variable region gene usage and were enriched in the proportion of CD4+V beta 5.2/5.3+ cells. CD4+V beta 5.2/5.3+ cells in the T cell lines were not increased after stimulation with purified protein derivatives or 65-kDa heat-shock protein but significantly increased after stimulation with staphylococcal enterotoxins C1 and D. Those cells showed increased cytolytic activity against target cells cross-linked by anti-V beta 5.2/5.3 and produced a large amount of interferon-gamma. These results indicated that CD4+V beta 5.2/5.3+ iIELs were preferentially activated in the inflamed lesions of Crohn's disease and may play a possible role in the triggering and progression of human inflammatory intestinal disease.

Adolescent↗
PubMed1996

Papillary fibroelastoma of the tricuspid valve in association with an atrial septal defect: report of a case.

Although papillary fibroelastoma is rare, it is the most common primary tumor of the heart valves. We describe herein the case of a 64-year-old woman scheduled to undergo atrial septal defect (ASD) repair, in whom a papillary fibroelastoma of the tricuspid valve was diagnosed by transesophageal echocardiography (TEE). Surgical resection of the papillary fibroelastoma at the time of ASD repair prevented the fatal embolization sometimes associated with this lesion. Thus, intraoperative TEE played an important role in identifying the location of the tumor and its anatomic attachment, and in assessing the adequacy of surgical treatment.

Echocardiography, Transesophageal↗
PubMed1996

Bilateral type diverticular disease of the colon.

7,543 double-contrast barium enema studied for the presence of diverticula which were classified into right-sided, left-sided and bilateral types, and the relationship of the frequency (detection rate) and numbers of diverticula to age were examined for the earlier (1982-87) and later (1988-92) periods. Diverticular disease was found in 22.2% of male and 15.5% of female examinees. The right-sided type predominated among the subjects. Frequency distribution by age of the bilateral type was similar to that of the left-sided type. Bilateral diverticular disease increased in frequency with advancing years in the sixth and seventh decade, the right-sided type increased in middle-aged subjects, and the left-sided type did not. The bilateral type was composed of diverticula in the right colon, where numbers were greater than in the pure right-sided type, but remained unchanged with increasing age, and diverticula in the left colon, where numbers were similar to the pure left-sided type, but did not increase with age. Increase in the prevalence of bilateral and not pure left-sided form has contributed to the recent increase in diverticula in the left colon among the Japanese, and might have been preceded by an increase in the right-sided type.

Adult↗
PubMed1996

Anteroaxillary thoracotomy facilitates the use of retrograde cerebral perfusion in distal aortic arch reconstruction.

Anteroaxillary thoracotomy in a 45-degree position provides an ideal view of the distal aortic arch and also makes direct superior vena caval cannulation possible for retrograde cerebral perfusion. This approach is especially useful in cases in which retrograde cerebral perfusion is indicated as an adjunct to deep hypothermic circulatory arrest in repair of the distal aortic arch.

Aorta, Thoracic↗
PubMed1996

Papillary carcinoma of the thyroid. Tall-cell variant with extensive lymphocyte infiltration.

Thirteen cases of tall-cell variant of papillary thyroid carcinoma (PTC) showing extensive lymphocyte and plasma cell infiltration within the fibrous stalks of the papillary architecture were compared with age-, sex-, and tumor size-matched cases of ordinary tall-cell variant without extensive lymphocyte infiltration and also with cases of PTC of the conventional type. All cases of the tall-cell variant of PTC with extensive lymphocyte infiltration exhibited the histologic features of chronic thyroiditis. Dissemination of tumor cells with the thyroid was significantly less frequent than in control cases, but there was no difference between the incidences of lymph node metastasis. Immunohistochemically, the lymphocytes infiltrating the carcinoma focus were mainly CD20+, CD45+, and CD45RO+ cells, that is, basically the same as those found in foci of chronic thyroiditis. No tumor recurrence was observed during the mean follow-up period of 3 years 8 months. The results of this study suggest that the tall-cell variant of PTC with extensive lymphocyte infiltration has less aggressive characteristics and a more favorable prognosis.

Adult↗
PubMed1996

Protein-losing enteropathy due to intestinal lymphangiectasia accompanied by mesenteric lymph node fibrosis.

An autopsy case of a 74-year-old man suffering from edema in the legs and diagnosed as protein-losing enteropathy due to intestinal lymphangiectasia is presented. He underwent a radical operation and radiotherapy for esophageal carcinoma at age 65 years and the onset of protein-losing enteropathy was at age 70. Postmortem examination disclosed widespread abnormalities of the duodenal and small intestinal lymphatics and mesenteric lymph node fibrosis. The mucosal lymphatic capillaries were markedly dilated. In the submucosal and serosal layers, the lymphatic vessels showed marked dilatation in some areas and fibrous occlusion with very thick muscle layers in others. All these lymphatic changes were presumed to be attributable to a reactive process secondary to lymph congestion, which it is suggested, was caused by the mesenteric lymph node fibrosis.

Aged↗