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S Hosoda

Publications and source records attributed to S Hosoda.

At least 145 records · Page 8Linked to original sources
PubMed1994

[Artifactual defect of inferior myocardium on 123I-metaiodobenzylguanidine myocardial SPECT: characteristic findings and preventive method on phantom study].

Discordance between planar and SPECT image of inferior myocardial defect on 123I-metaiodobenzylguanidine myocardial scintigraphy (MIBG) was occasionally observed in the clinical studies. The purpose of this study is to clarify the existence of artifactual myocardial defect on MIBG SPECT image. Phantom study was performed in various kinds of situation using triple gamma camera. Artifactual defect adjacent to the liver was significantly observed in the case of increased liver/heart uptake ratio more than 2:1. Artifactual defect was markedly observed in the 180 degrees than that in the 360 degrees SPECT acquisition. To avoid artifactual defect during SPECT acquisition, liver phantom was moved down to the foot direction (vanishing liver position). In this phantom position, artifactual defect adjacent to the liver was not observed on reconstructed myocardial SPECT image. The vanishing liver position was also applicable to human study. Human body was inclined to right side at an angle of 15 degrees, artifactual defect could be avoided. Further study is needed to analyze the cause of this artifactual defect and to conform the preventive method with vanishing liver position in the routine myocardial SPECT examination.

3-Iodobenzylguanidine↗
PubMed1993

Differential cytokine regulation of complement C3, C4, and factor B synthesis in human intestinal epithelial cell line, Caco-2.

In the intestinal tract, the local synthesis of C3 and components of both the classical (C4) and alternative (factor B) C activation pathway has previously been demonstrated in vivo. However, the cellular source of this local C synthesis has not been identified. In this study, we demonstrated the syntheses of C3, C4, and factor B in the human colonic adenocarcinoma cell line Caco-2, which is regarded as a good experimental model of normal human intestinal epithelial cells. The results of metabolic labeling experiments indicated that the intra- and extracellular molecular sizes and subunit structures of Caco-2-derived C3, C4, and factor B were compatible with previously reported values for these components in other cells. The functional activities of C3 and C4 in the supernatants were also demonstrated by hemolytic titration assay. Furthermore, C syntheses in this line were independently upregulated by several human cytokines: C3 synthesis was dose-dependently enhanced by the addition of IL-1 beta or TNF-alpha; C4 synthesis was enhanced by the addition of IL-6 or IFN-gamma in the same manner; and the addition of IL-1 beta or IL-6 also induced a dose-dependent increase in factor B synthesis. These enhancing effects were confirmed to be specific for individual cytokines by experiments using anti-human cytokine antibodies. It is likely that intestinal epithelial cells are local production sites of C3, C4, and factor B, and that local C syntheses in the intestine are independently regulated by several cytokines, derived from monocytes/macrophages and T cells resident in the mucosal microenvironment.

Adenocarcinoma↗
PubMed1993

Characterization of gastrin/CCK receptors on gastric carcinoid tumor membrane of Mastomys natalensis.

Recently, we identified the specific binding site for gastrin on the gastric carcinoid tumor of Mastomys (Praomys) natalensis. In this study, precise characterization of the gastrin binding site on these tumors was performed. Both 125I-human gastrin I (gastrin) and 125I-CCK-8 bound specifically to the cell membrane, and Scatchard analysis revealed a high affinity binding site for each ligand with similar Kd and Bmax values. The specific binding of both 125I-gastrin and 125I-CCK-8 was displaced in a concentration-dependent manner by various related peptides with a relative potency order of CCK-8 > or = gastrin < des(SO3)CCK-8. In addition, L364,718 as well as L365,260 displaced the binding of both ligands with similar potencies. Furthermore, not only gastrin but also CCK-8 increased [Ca2+]i in these tumor cells, the action of both being inhibited by L364,718 as well as by L365,260 (10(-7) M). These results suggest that the carcinoid tumor of Mastomys possesses a high affinity gastrin/CCK binding site coupled to the increase of [Ca2+]i.

Animals↗
PubMed1993

Effect of intrinsic CCK and CCK antagonist on pancreatic growth and pancreatic enzyme secretion in pancreaticobiliary diversion rats.

When pancreaticobiliary diversion (PBD) surgery was performed in rats, plasma CCK level increased, the pancreas grew mainly by proliferation, and pancreatic trypsinogen showed a remarkable increase, although amylase and lipase synthesis were somewhat decreased. The sensitivity of amylase release against CCK-8 in the pancreatic acini decreased when plasma CCK level was high. These changes in pancreatic growth and pancreatic enzyme secretion caused by PBD were completely inhibited by the CCK-receptor antagonist loxiglumide. From these results, intrinsic CCK was considered to play an important role in both pancreatic enzyme synthesis and proliferation.

Amylases↗
PubMed1993

Effect of epidermal growth factor by different routes of administration on the small intestinal mucosa of rats fed elemental diet.

This study was undertaken to investigate the effect of epidermal growth factor (EGF) on the rat small intestinal mucosa by three different routes of administration. Four-week-old rats were fed elemental diet for 4 weeks and were administered EGF either subcutaneously, intraluminally or intraperitoneally with mini-osmotic pumps for a week. Intraperitoneal administration of EGF resulted in a significant increase of mucosal wet weight, mucosal content of protein and DNA, villus height, crypt depth and crypt cell production rate. Intraluminal or subcutaneous administration of EGF tended to increase those morphological and proliferative parameters, but did not cause any significant change. We conclude that EGF caused the hyperplasia of the small intestine of rats maintained on oral elemental diet and that this trophic effect was clearly shown by the intraperitoneal route of administration, rather than by the intraluminal route. These results suggest that EGF receptors located in the basal portion of crypt cells play a more important role than those located in the microvillous membrane.

Amine Oxidase (Copper-Containing)↗
PubMed1993

The human colon cancer cell line CaCo-2 produces secretory components during enterocytic differentiation.

A human colon cancer cell line CaCo-2 differentiates spontaneously by expressing enterocytic phenotypes after the confluence of the culture. The authors examined a production of secretory components (SC) by CaCo-2 in relation to its differentiation. The SC production showed an increase immediately after the cells came to confluence, and reached its peak production during the 6th to the 9th day after confluence of the culture. SC production decreased remarkably after the 10th day. On the other hand, the activity of alkaline phosphatase of CaCo-2 showed a gradual increase up to the 18th day after confluence. The production of SC was not affected by the presence of dimeric IgA in the culture. Interferon-gamma enhanced SC production of CaCo-2 with dose-dependent manner. These observations indicate that capability of SC production of CaCo-2 is enhanced in the early stage of differentiation but is reduced in the late stage. Moreover, CaCo-2 provides a useful model for studying the regulation of SC production in enterocytic differentiation.

Adenocarcinoma↗
PubMed1993

Relationship between amino acid transport and protein synthesis in rat isolated pancreatic acini under stimulation with cholecystokinin.

The effects of cholecystokinin octapeptide (CCK8) on amino acid transport and protein synthesis in the pancreatic acini were determined. The question of whether those effects differed between amino acid transport systems A and L was also investigated. The influx of alpha-[3H]aminoisobutyric acid (AIB, system A) and [14C]cycloleucine (system L) into isolated rat pancreatic acini and the incorporation of [14C]alanine (system A) and [3H]leucine (system L) into trichloroacetic acid (TCA)-precipitable protein in pancreatic acini were studied in the presence of various concentrations of CCK8. CCK inhibited the amino acid transport across the basolateral membrane of pancreatic acini. This effect was mediated by Ca2+, and was more responsive to amino acid transport system L than to A. CCK also inhibited protein synthesis in pancreatic acini in a dose-dependent manner. The inhibition of protein synthesis by CCK was thought to be mainly due to the inhibition of amino acid transport by CCK. Therefore, the predominant utilization of extracellular amino acids in protein synthesis was suggested.

Alanine↗
PubMed1993

Effect of reconstituted basement membrane on growth and secretory function in pancreatic acinar AR42J cells.

This study investigated the influence of extracellular matrix on growth and secretory function associated with cholecystokinin (CCK) receptors in pancreatic acinar AR42J cells, using reconstituted basement membrane derived from Engelbreth-Holm-Swarm (EHS) tumor. The cells were cultured with basement membranes of two different thickness, 1 mg/ml protein equivalent (thick RBM) and 50 micrograms/ml protein equivalent (thin RBM). In cells cultured with thin RBM, the secretory function and the number of CCK receptors increased, but cell growth did not increase significantly. Cells cultured with thick RBM showed remarkable cell growth, but secretory function and the number of CCK receptors were reduced. There was little change in CCK receptor affinity. It was concluded that the extracellular matrix plays a crucial role in the proliferation and differentiation of AR42J cells and further, the quantitative difference of matrix components strongly influenced the up- and down-regulation of CCK receptor in the cells via cell-matrix interaction.

Amylases↗
PubMed1993

Aldolase C in neuroendocrine tumors: an immunohistochemical study.

The expression of cerebral type aldolase C was investigated immunohistochemically in six varieties of neuroendocrine (n = 57) and six types of non-endocrine tumor (n = 76) using the avidin-biotin complex method. Aldolase C expression in the neuroendocrine tumors was also compared with those of chromogranin and gamma enolase. Aldolase C was detected in all the islet cell (7/7) and carcinoid tumors (10/10), thyroid medullary carcinomas (7/7), and pheochromocytomas (10/10), as well as in the majority of neuronal tumors (8/10) and bronchial small cell carcinomas (10/13). Chromogranin immunoreactivity was restricted to the tumors with abundant neuroendocrine granules. Gamma enolase positivity was generally similar to that of aldolase C, but there were some differences. Amongst the bronchial small cell carcinomas, three tumors negative for gamma enolase were positive for aldolase C, while another three tumors were positive for gamma enolase only. However all the small cell carcinomas were positive for at least one of these two enzymes. Aldolase C was detected in 28 (37%) of the 76 non-endocrine tumors and tended to be expressed preferentially in the differentiated portions of these tumors. Although aldolase C was expressed in many bronchial squamous cell carcinomas, the immunoreactivity was localized mainly in keratinizing foci and the less differentiated parts of these tumors expressed the enzyme only occasionally. Thus aldolase C, in conjunction with other neuroendocrine-associated markers, may be of value in identifying tumors of neuroendocrine type.

Adenoma, Islet Cell↗
PubMed1993

A triangular conditioning voltage wave does not influence spontaneous neuronal activity in the rat striatum.

A triangular potential wave applied shortly before each measuring triple pulse has been used in in vivo voltammetric experiments to ensure the maintenance of a high level of stability and sensitivity in the carbon fiber electrode. To investigate whether a triangular wave (0- +/- 1500 mV, 10 V/s slope) and a consecutive triple pulse affect spontaneous neuronal firing, extracellular recordings were made in the rat striatum at a distance of about 200-300 microns from the carbon fiber electrode while these potentials were being delivered. No significant change in the rate of spontaneous firing was found. A triangular pulse has proven to be very effective in lengthening the measurement lifetime of the carbon fiber electrode without interfering with the spontaneous activity of striatal neurons.

Animals↗
PubMed1993

Insulin-like growth factor I receptors in human cardiac myocytes and their relation to myocardial hypertrophy.

Specific binding sites for insulin-like growth factor I (IGF-I) and their expression during cardiac myocyte hypertrophy were studied by autoradiographic analysis of right ventricular biopsy specimens from patients with hypertrophic cardiomyopathy (9 cases), dilated cardiomyopathy (8 cases), and sick sinus syndrome (5 cases). Frozen specimens were cut into 5 microns-thick sections and thaw-mounted on albumin-coated slides. After incubation with [125I]IGF-I, with or without excess cold IGF-I, autoradiography was performed, and grains over myocytes were counted microscopically. Binding of [125I]IGF-I was inhibited in a dose-dependent manner by unlabeled IGF-I and competed for by IGF-I > IGF-II > insulin. The maximal grain density was higher in hypertrophic cardiomyopathy (186 +/- 47/1.8 x 10(-2) mm2) than in dilated cardiomyopathy (124 +/- 13/1.8 x 10(-2) mm2) or sick sinus syndrome (98 +/- 18/1.8 x 10(-2) mm2) (p < 0.01). There was a strong correlation between the maximal grain density and the diameter of right ventricular myocytes in hypertrophic cardiomyopathy (r = 0.83), but no similar correlation was observed in dilated cardiomyopathy or sick sinus syndrome. These data suggest that IGF-I receptors are present in adult human cardiac myocytes, and that IGF-I receptors are related to the development of myocyte hypertrophy in hypertrophic cardiomyopathy.

Adolescent↗
PubMed1993

Combined assessment with myocardial contractility and an index related to ventricular afterload in patients with isolated severe mitral regurgitation undergoing valve replacement. A retrospective study.

The afterload to the left ventricle increases following valve replacement in chronic mitral regurgitation (MR), yet there has been no study taking into account left ventricular (LV) afterload. In 43 patients with isolated chronic MR undergoing mitral valve replacement (MVR), we calculated LV wall stress using preoperative LV end-diastolic dimensions and diastolic aortic pressure (predictive LV wall stress = pWS). This value would represent LV wall stress at the instant of aortic valve opening immediately after MVR, assuming that LV end-diastolic dimensions and the aortic pressure did not change after operation. We also calculated end-systolic wall stress/volume index (ESS/ESVI) ratio, an index of myocardial function. None of 15 patients with the ESS/ESVI ratio > 1.6 had postoperative mortality or morbidity, whereas among the 26 patients with the ESS/ESVI ratio < 1.6, 12 patients had mortality (3 patients) and/or morbidity requiring intraaortic balloon pumping or prolonged catecholamine support. Three patients who died had pWS > 200 kdynes/cm2. Including these 3, all 5 patients whose pWS > 200 had mortality or severe morbidity immediately after surgery. In contrast, among the 38 patients with lower pWS, none died and only 7 patients (18%) had morbidity. Thus, patients who had a low contractility index and a high predictive afterload value had high mortality and morbidity. We conclude that the prediction of postoperative mortality and morbidity is improved by combined assessment of myocardial function and the hypothetical postoperative LV afterload.

Catecholamines↗
PubMed1993

Treatment of ulcerative colitis with camostat mesilate, a serine protease inhibitor.

We were able to induce and maintain remission with camostat mesilate, a serine protease inhibitor, in two patients with ulcerative colitis, to whom salicylazosulfapyridine could not be administered due to previous side effects. The enzymatic activity of proteases from granulocyte, pancreatic juice and bacteria is possibly harmful to the inflamed colonic mucosa. Camostat mesilate can be expected to have an anti-inflammatory effect on the damaged mucosa of inflammatory bowel disease.

Adult↗
PubMed1993

[Effect of combination chemotherapy for elderly patients with malignant lymphoma].

The remedial effect in elderly patients with malignant lymphoma in two groups treated with combination chemotherapy, one including doxorubicin (ADM) (A group) and the other excluding ADM (V group) were compared. Forty patients aged 65 years or more with malignant lymphoma were entered from January 1982 to December 1991. The A group was made up of 10 patients and the V group of 18 patients. As to pathological classification, two of the A group had low grade malignancy lymphoma, four had intermediate grade and three had high grade. Four of the V group had low grade, eight had intermediate grade and five had high grade. In terms of clinical stage, three of the A group were in stage II, 3 in stage III and 4 in stage IV. Two of the V group were in stage II, 7 in stage III and 9 in stage IV. The effective rate for the A group was 90% and the V group was 61%. The survival rate over five years in the A group was 37.5% and 21.8% in the V group. There were no adverse effects on the cardiovascular system in the A group. No significant differences of effects were shown in this study, however, the A group showed a higher tendency in terms of the CR rate and the survival rate. Cases of early death during chemotherapy were few and the quality of life of the patients was raised by discharge in the A group. Combination chemotherapy including ADM appears to be satisfactory in aged patients with malignant lymphoma.

Aged↗
PubMed1993

The trophic effects of long chain triglycerides on the atrophic ileal mucosa of rats.

Rats with atrophic intestinal mucosa due to enteral nutrition supplied by an elemental diet (ED) for 4 weeks or more, received a fat-enriched ED containing 10% long chain triglycerides (10% FED) orally. The atrophic ileal mucosa became trophic 4 weeks after administration of the 10% FED. Ornithine decarboxylase activity in the ileal mucosa increased 3 days after the administration of 10% FED. Rats with atrophic intestinal mucosa that had undergone a 70% proximal jejunoileectomy, received an oral ED containing 4% long chain triglycerides (4% FED). In the jejunoileectomized rats, marked proliferation of the remaining ileum was observed irrespective of diet, when compared with the transected control group. In the transected group, the 4% FED had trophic effects on the ileum, but in the jejunoileectomized group, the 4% FED had no significant trophic effect on the remaining ileum. In conclusion, long chain triglycerides had mild trophic effects on ileal mucosa and were effective in the treatment of atrophic intestinal mucosa. However, the trophic effects of fat were apparently masked by the marked proliferation of the ileal mucosa following jejunoileectomy.

Animals↗
PubMed1993

[A case of amylase producing lung cancer].

The patient was a 72-year-old man, who was admitted to our hospital because of cough. Chest X-rays showed a mass shadow in the right lower lung field. Amylase activities in serum and urine were extremely high. Amylase isozyme pattern identified salivary type amylase. Cytological examination of the sputum suggested adenocarcinoma. Amylase activities in serum and urine gradually decreased with the administration of chemotherapy. Afterwards, pleural effusion increased, and the amylase activity in pleural fluid was also extremely high. Pleural fluid also showed adenocarcinoma. Enzyme-labeled antibody method (PAP) on this specimen from pleural fluid proved that tumor cells were producing amylase ectopically.

Adenocarcinoma↗