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Biomedical subjects

T Yamamura

Publications and source records attributed to T Yamamura.

At least 361 records · Page 20Linked to original sources

Passive transfer of experimental allergic encephalomyelitis induced by proteolipid apoprotein.

In an attempt to obtain insight into the pathogenesis of proteolipid apoprotein (PLP)-induced experimental allergic encephalomyelitis (EAE) in Lewis rats (Yamamura et al. 1986), PLP-sensitized lymph node cells or spleen cells were passively transferred into normal or irradiated (400 rad) recipients after incubation with concanavalin A or PLP. Clinical EAE manifested by paraparesis was successfully transferred into irradiated recipients with 2 - 2.5 X 10(8) of the primary cultured cells and histologic EAE could be transferred with as few as 5 X 10(7) cells into naive recipients. This is the first demonstration of passive EAE induced with PLP-sensitized lymphoid cells and suggests the pathogenetic importance of cell-mediated immunity to PLP.

Animals↗

Experimental allergic encephalomyelitis induced by proteolipid apoprotein in Lewis rats.

Experimental allergic encephalomyelitis (EAE) was induced in inbred Lewis rats by sensitization with bovine white matter proteolipid apoprotein (PLP). 18-61 days after a single injection of 100 micrograms of PLP, 12 of 31 rats (39%) developed clinical EAE and 18 of 23 (78%) showed pathologic EAE with significant demyelination. Lymphocyte proliferative responses and antibodies to PLP were elevated but did not correlate with the clinical or pathologic state. This is the first demonstration of PLP-induced EAE with significant demyelination in rats and will contribute to the study of autoimmune demyelination.

Animals↗

Nodular fascitis of the mandible in a child.

Nodular fascitis is an unusual, tumor-like, proliferative, fibroblastic lesion with infiltrative properties. We describe a case of nodular fascitis appearing in the mandible of a 2-year-old boy. A brief review of the literature on this lesion arising from intra or perioral regions, and the importance of differential diagnosis for this lesions are discussed.

Child, Preschool↗

Two cases of adult T-cell leukaemia.

A 70-year-old male and a 46-year-old female, both living in Japan, were seen because of multiple erythematous papules and plaques on the trunk and extremities. The peripheral white blood cell counts were increased to 30,000-80,000/mm3. The majority of white cells had characteristic lobulated and deeply indented nuclei. The patients and most of their family members had anti-ATLV antibody. Using an OKT series of monoclonal antibodies the tumour cells were found to be T-cells. Trisomy 21 was detected in the first case and ATL virus proviral DNA in the second.

Aged↗

Metastasizing atrial myxoma: a case with multiple subcutaneous tumours.

We report a case with rapidly growing subcutaneous and intra-muscular tumours that were identical histopathologically to a pre-existing left atrial myxoma. No invasion of visceral organs or skeleton was found. This is a very rare case of metastasizing myxoma with wide dissemination and rapid metastastic growth, despite the benign appearance of the original tumour.

Adult↗

Kimura's disease and its relation to angiolymphoid hyperplasia with eosinophilia: report of three cases and review of the literature.

Kimura's disease, eosinophilic granuloma of soft tissues, is a chronic inflammatory condition and appears as subcutaneous tumor-like nodules in the head and neck regions. Histopathologically, it is characterized by the presence of lymphoid follicles, marked infiltration of eosinophils, fibrosis and vascular proliferation. This disease occurring in the orofacial region is relatively rare, only 14 cases having been previously reported. We describe 3 additional cases of Kimura's disease and discuss these in relation to angiolymphoid hyperplasia with eosinophilia.

Adolescent↗

Activation of effector cells of experimental allergic encephalomyelitis in Lewis rats: comparison of T-cell lines with primary cultured lymph node cells.

We studied the mechanism of activation of effector cells in experimental allergic encephalomyelitis (EAE) by using T-cell lines (EAE/TL) reactive against guinea pig myelin basic protein generated from in vivo primed lymph node cells (LNC) of Lewis rats. EAE-effector cells are activated in the presence of a specific antigen and antigen-presenting cells (APC) with a compatible Ia antigen. The antigen presentation occurs during the first 18 h. EAE-effector cells cannot be activated by allogeneic stimulator cells, but a nonspecific T-cell mitogen, concanavalin A, can activate the effector cells in the presence of syngeneic as well as allogeneic APC.

Animals↗

Impaired contractile motility of the gallbladder after gastrectomy.

Contractile motility of the gallbladder was compared using a real-time ultrasonography in 13 patients with gastric ulcer and 31 patients with gastric cancer who had undergone either subtotal or total gastrectomy within 1 month previously. Contractile motility of the gallbladder after oral administration of dried egg yolk (Daiyan, Maruishi, Osaka), which was slightly but not significantly reduced in patients with gastric ulcer, was remarkedly impaired in patients with gastric cancer who had either subtotal or total gastrectomy including radical lymph node dissection. Especially, maximum contractile rate after Daiyan in Billroth II patients was significantly reduced than that of Billroth I patients. Intramuscular injection of naloxone (0.4 mg), which had no effects on contractions after Daiyan in healthy subjects, significantly improved the hypomotility in response to Daiyan in these gastric cancer patients. It was suggested, therefore, that the possible roles of various anatomical and mechanical changes resulting from gastrectomy including vagotomy and sympathectomy, and in particular exclusion of duodenum from digestive circuits and relative or absolute excess of endogenous opioids, were involved in the control of the gallbladder motility within 1 month after gastrectomy including lymphadenectomy.

Colectomy↗

Fate of bone marrow-derived cultured mast cells after intracutaneous, intraperitoneal, and intravenous transfer into genetically mast cell-deficient W/Wv mice. Evidence that cultured mast cells can give rise to both connective tissue type and mucosal mast cells.

Both connective tissue mast cells and mast cells grown in vitro are derived from multipotential hematopoietic stem cells, but these two mast cell populations exhibit many differences in morphology, biochemistry, and function. We investigated whether the phenotype of cultured mast cells or their progeny was altered when the cells were transferred into different locations in vivo. Cultured mast cells were immature by ultrastructure, and stained with alcian blue but with neither safranin or berberine sulfate, a fluorescent dye that binds to the heparin of connective tissue mast cell granules. By contrast, mast cells recovered from the peritoneal cavity of congenitally mast cell-deficient (WB X C57BL/6)F1-W/Wv (WBB6F1-W/Wv) mice 10 wk after intraperitoneal injection of cultured WBB6F1-+/+ or C57BL/6-bgJ/bgJ mast cells stained with both safranin and berberine sulfate. Staining with berberine sulfate was prevented by treatment of the cells with heparinase but not chondroitinase ABC, suggesting that the adoptively transferred mast cell population had acquired the ability to synthesize and store heparin. Furthermore, the recovered mast cells were indistinguishable by ultrastructure from the normal mature peritoneal mast cells of WBB6F1-+/+ mice, and contained substantially more histamine than mast cells studied directly from culture. Intravenous injection of cultured mast cells resulted in the development of safranin-and berberine sulfate-positive mast cells in the peritoneal cavity, spleen, skin, and glandular stomach muscularis propria. Mast cells also developed on the glandular stomach mucosa, but these cells stained with alcian blue rather than safranin, and did not stain with berberine sulfate. This result suggests that cultured mast cells can give rise to mast cells of either the connective tissue type or mucosal phenotype, depending on anatomical location. Furthermore, transplantation of cultured mast cells into WBB6F1-W/Wv mice had no measurable effect on the anemia of the recipient mice, suggesting a possible strategy for repairing the mast cell deficiency of WBB6F1-W/Wv mice without affecting other bone marrow-derived populations such as erythrocytes. Intravenous injection of representative connective tissue type mast cells (30-50% pure peritoneal mast cells derived from WBB6F1-+/+ mice) gave results similar to those obtained with cultured mast cells: mast cells developing in the peritoneal cavity, skin, spleen, and glandular stomach muscularis propria of WBB6F1-W/Wv recipients stained with safranin and berberine sulfate, whereas mast cells developing in the mucosa of the glandular stomach stained only with alcian blue.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Bombesin evoked acetylcholine release from the guinea pig antrum.

Bombesin induced contraction and acetylcholine (ACh) release of the longitudinal muscle strip of the guinea pig antrum were examined using the standard organ bath technique and the superfusion system. Bombesin increased frequency and tonus of rhythmic contraction in a dose dependent manner (10(-10)M - 10(-7)M). The effects of bombesin on frequency of contraction were not affected by atropine, propranolol, phentolamine, hexamethonium and tetrodotoxin. The effects on tonus, on the other hand, were significantly reduced by atropine, and the dose response curve to bombesin was shifted to the right. There was a remarkable increase of 3H-ACh release by the superfusion of bombesin (10(-8)M), which was almost completely abolished in Ca-free medium, but not affected by hexamethonium and tetrodotoxin. These results suggest that mechanism of bombesin effects on frequency is different from that on tonus; frequency response to bombesin is not dependent on autonomic nervous system but due to a direct effect on smooth muscle cells, whereas tonic response to the peptide is partly mediated by ACh release via a mechanism independent of sodium spike.

Acetylcholine↗

The failure of truncal vagotomy to affect motilin release in dogs.

To elucidate the relationship between vagus nerve and motilin release, we have studied the influence of truncal vagotomy with pyloroplasty (TV) on motilin release in the fasting state and for 120 min following an intraduodenal administration of 10 g glucose in a 50-ml water solution or 5 g soybean oil. TV did not influence the intermittent fluctuation or concentration of plasma motilin in the fasting state. Intraduodenal glucose administration inhibited motilin release, but this was not affected by TV. Intraduodenal fat administration accelerated motilin release, but this effect also was not affected by TV. These results suggest that motilin secretion in the fasting state and after nutrient ingestion is not influenced by TV.

Animals↗

Effect of truncal vagotomy on intestinal phase of pancreatic polypeptide release in dogs.

In order to elucidate the role of the vagus nerve in the intestinal phase of pancreatic polypeptide (PP) release, mongrel dogs were given a 4-min intraduodenal infusion of saline, 20% glucose, or 10% soybean oil solution (50 ml each), before and one month after truncal vagotomy including pyloroplasty (TV). The saline infusion did not change the basal PP level, while the glucose infusion elicited a monophasic transient PP release, and the soybean oil infusion elicited a monophasic prolonged PP release in the intact dogs. The PP response following glucose infusion was almost abolished after TV, while the PP response to fat was attenuated, but a significant increase was nevertheless observed after TV. These results suggest that the vagus nerve has an important role in the intestinal phase of PP release and that other factors, e.g. hormonal, might also be involved in the regulatory mechanism, especially after fat loading.

Animals↗

The occurrence of glycosphingolipids containing mannose in the sea-water bivalve, Meretrix lusoria (Hamaguri).

Total neutral and acidic glycosphingolipids were prepared from whole tissues of the sea-water bivalve, Meretrix lusoria, and the former preparation was further fractionated into subgroups by silicic acid column chromatography. The fractions obtained as mono-(ceramide monosaccharide, CMS), di-(CDS) and triglycosylceramides (CTS) were characterized by thin-layer chromatography, partial hydrolysis with exoglycosidases, methylation studies, CrO3 oxidation, and GLC analysis of the component sugars, fatty acids and long-chain bases. The following structures are proposed: Gal-Cer and Glc-Cer for CMS, Gal(beta 1----4)Glc-Cer and Man(beta 1----4)Glc-Cer (MlOse2Cer) for CDS, Man(alpha 1----3)Man(beta 1----4)Glc-Cer (MlOse3Cer) and Gal(alpha 1----3)Man(beta 1----4)Glc-Cer (II3 alpha Gal-MlOse2Cer) for CTS. To our knowledge II3 alpha Gal-MlOse2Cer has not previously been reported. The fatty acid composition of CMS, CDS, and CTS consisted almost entirely of saturated C16-C24 acids with large amounts of 2-hydroxypalmitic acid and 2-hydroxystearic acid. The long-chain bases consisted of 4-sphingenine and 4,8-sphingadienine. More complex neutral glycolipids than CTS, as well as an acidic glycolipid, were examined by TLC and GLC of the constituent sugars, and an immunochemical technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗