Search PubMed⌕ Search

Biomedical subjects

S Shimada

Publications and source records attributed to S Shimada.

At least 235 records · Page 13Linked to original sources
PubMed1994

High-molecular-weight hyaluronic acids inhibit chemotaxis and phagocytosis but not lysosomal enzyme release induced by receptor-mediated stimulations in guinea pig phagocytes.

The effects of high-molecular-weight (HMW) hyaluronic acids (HAs) of 1.9 x 10(6) Da, 8 x 10(5) Da and 3 x 10(5) Da on the receptor-mediated functions of guinea pig peritoneal phagocytes were studied. HMW-HAs of 1.9 x 10(6) Da (HA190) and 8 x 10(5) Da (HA80) effectively inhibited the chemotactic activity of polymorphonuclear leukocytes (PMNs) for formyl-Met-Leu-Phe (fMLP). The degree of inhibition was dose-dependent and the concentrations of HA190 and HA80 required for 50% inhibition were 0.5-1.5 mg/ml and 1.5-2.5 mg/ml, respectively. HMW-HA of 3 x 10(5) Da (HA30) hardly affected the chemotaxis within a concentration range of 0.5-5.0 mg/ml. The phagocytic activities of PMNs and macrophages (Mphis) for serum-opsonized zymosan (SOZ) and polystyrene latex particles were also inhibited by these HAs in a dose- and molecular-weight-dependent manner and HA190 was again the most inhibitory. By contrast, the release of lysosomal enzyme from Mphis stimulated with SOZ was not significantly affected by HMW-HAs at any concentration used. Furthermore, the binding of [3H]fMLP with PMNs and the rosette formation of Mphis with SOZ were not influenced by the presence of HMW-HAs. These findings suggested that the binding of HMW-HAs to the HA receptors on PMNs and M phi s might produce certain intracellular signals which would be responsible for the suppression of the chemotaxis and the phagocytosis but not for the release of lysosomal enzyme. For the generation of such signals, higher-molecular-weight HMW-HAs would be more effective than lower one.

Animals↗
PubMed1994

Brown papules and leukoderma in Darier's disease: clinical and histological features.

We report a Japanese case of Darier's disease with brown and white papules or maculae distributed on the neck, trunk and dorsa of hands. Both brown papules and leukoderma showed typical histological features of Darier's disease. Moreover, there were much fewer melanocytes and melanosomes in the epidermis of both lesions. The corneal layer of the brown papules was far thicker than that of the leukoderma. Therefore, the thick corneal layer of the brown papules may prolong the retention of a few melanosomes or a little melanin to induce hyperpigmentation, while the thin corneal layer of leukoderma may not do so, thereby producing hypopigmentation. The difference in clinical and histological courses after involvement of melanocytes was proposed to be the cause of the discrepancy between the previous reports. We conclude that leukoderma was the primary lesion, the postinflammatory depigmented spots, or the atypical or subclinical eruption of Darier's disease.

Adult↗
PubMed1994

Recurrent malignant histiocytosis with cerebrospinal involvement--case report.

A 61-year-old male presented with recurrent malignant histiocytosis of the brain manifesting as nausea and headache. Malignant histiocytosis is a disorder of proliferating histiocytes characterized by a rapidly progressive and fatal course, but central nervous system involvement is relatively rare. Magnetic resonance (MR) imaging demonstrated cerebrospinal fluid (CSF) dissemination of histiocytes as a low-intensity area on the T1-weighted image with marked gadolinium-diethylenetriaminepenta-acetic acid enhancement and a high-intensity area on the T2-weighted image. CSF cytological examination revealed an increased level of atypical histiocytes. Brain and spine irradiation, and intrathecal methotrexate and prednisolone administration induced remission. MR imaging is particularly useful for the diagnosis of meningeal dissemination of malignant histiocytosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

A study of reservoir implantation--especially with saphenous vein graft catheterization.

Intra-arterial infusion chemotherapy is commonly used to treat hepatocellular carcinomas (HCC) and metastatic liver cancer after hepatectomy or in unresectable patients, and it has been adopted at Kurume University Hospital as a treatment for HCC. As complications of reservoir implantation have been encountered, the implantation procedure needs improvement. Procedures were compared in a study with 109 patients who were available for follow-up observation among 116 patients who underwent reservoir implantation. Fifty-six of the patients received intraoperative implantation through the gastroduodenal artery (GDA catheterization), 31 received external catheterization (EXT catheterization) and 22 received catheterization using a saphenous vein graft (SVG catheterization). The complication rates were 75.0%, 9.7% and 13.9% and the one-year patencies were 44.1%, 70.6% and 79.4%, respectively. GDA catheterization was no better than the other two procedures and it had a higher incidence of complications and a lower patency. SVG catheterization achieved good patency, although it had a little higher incidence of complications than external catheterization. It was presumed to be a procedure that would ensure reservoir implantation even in patients with a winding or variation of hepatic artery.

Catheters, Indwelling↗
PubMed1994

Effect of an angiotensin II receptor antagonist, TCV-116, on rat carotid artery neointimal formation after balloon injury.

Arterial injury by a balloon catheter produces marked smooth muscle cell proliferation and the participation of angiotensin II in this response has been suggested. In this study, we examined the effect of a novel angiotensin II type I receptor antagonist, TCV-116, on neointimal formation after rat carotid artery balloon injury. Oral administration of TCV-116 at doses of 1, 5 or 10 mg/kg/day significantly reduced the cross-sectional intimal area by 30%, 46% and 54%, respectively, and reduced the ratio of the intimal to medial cross-sectional areas by 23%, 41% and 50%. An angiotensin-converting enzyme inhibitor, lisinopril, had an effect similar to that of TCV-116. The effect of both drugs was significantly correlated with the reduction of both blood pressure and cardiac hypertrophy. We conclude that TCV-116 can prevent neointimal formation after balloon injury as well as reducing blood pressure and preventing cardiac hypertrophy.

Angiotensin Receptor Antagonists↗
PubMed1994

Vigintiphobia, unbound bilirubin, and auditory brainstem responses.

OBJECTIVE: The management of nonhemolytic hyperbilirubinemia in term newborns is controversial. To evaluate the usefulness of serum unbound bilirubin concentrations (UBCs) in the management of hyperbilirubinemia, we compared the concentrations with abnormal auditory brainstem responses (ABRs). METHODS: ABRs and serum UBCs in 37 hyperbilirubinemic term newborns (total bilirubin concentrations [TBCs] > or = 20 mg/dL and direct bilirubin concentrations < 2 mg/dL) were measured before treatment with either phototherapy or exchange transfusions. Eight of these newborns had blood incompatibilities. These hyperbilirubinemic newborns were divided into three groups according to the findings of ABR: group A, normal ABR (n = 18); group B, prolonged latency of wave I only (n = 8); and group C, prolonged interpeak latency of wave I-III/I-V and/or poor amplitude (n = 11). RESULTS: The peak TBC was significantly different between groups A and C (22.8 +/- 2.2 mg/dL and 25.4 +/- 2.5 mg/dL, respectively; P < .05), though there were no differences between groups A and B and between groups B and C. The peak UBCs in groups B (1.27 +/- 0.7 micrograms/dL) and C (1.34 +/- 0.37 micrograms/dL) were significantly higher than in group A (0.78 +/- 0.26 microgram/dL) (P < .05 and P < .01, respectively), though there was no significant difference in the peak UBC between groups B and C. Abnormal ABR findings were more clearly associated with the level of UBC at 1.0 microgram/dL than that of TBC at 23 mg/dL by multiple logistic regression analysis (odds ratio = 16.6, P = .0026, vs 4.2, P = .1272). CONCLUSIONS: These results suggest that measuring UBC may help in evaluating the possible risk of bilirubin encephalopathy in full-term newborns when there is vigintiphobia (fear of 20).

Bilirubin↗
PubMed1993

Cellular localization of serotonin transporter mRNA in the rat brain.

Expression of serotonin (5-hydroxytryptamine, 5-HT) transporter mRNA in the rat brain was examined by in situ hybridization histochemistry with a synthetic oligonucleotide probe. 5-HT transporter mRNA was expressed in neurons in most of the raphe nuclei. The dorsal and median raphe nuclei contained intensely labeled neurons, while the caudal linear nucleus, raphe magnus nucleus, raphe pontis nucleus, raphe pallidus nucleus and the raphe obscurus nucleus contained weakly or moderately labeled neurons. The localization pattern of the 5-HT transporter mRNA-positive neurons coincides fairly well with that of 5-HT-immunoreactive neurons, indicating that 5-HT transporter is primarily located in serotonergic neurons.

Animals↗
PubMed1993

Improved radioimmunotherapeutic efficacy of an anticarcinoma monoclonal antibody (131I-CC49) when given in combination with gamma-interferon.

The moderately differentiated human colon tumor cell line, HT-29, constitutively expresses low levels of the high molecular weight mucin, tumor-associated glycoprotein 72 (TAG-72), and the M(r) 180,000 carcinoembryonic antigen (CEA) when grown as s.c. tumors in athymic mice. We report that the in vivo administration of gamma-interferon (IFN-gamma) resulted in a time- and dose-dependent increase in both TAG-72 and CEA expression in the HT-29 tumors. Immunohistochemical staining revealed a more homogeneous TAG-72-positive tumor cell population after IFN-gamma. Furthermore, both anti-TAG-72 and anti-CEA monoclonal antibodies (MAbs) showed enhanced localization to the HT-29 tumors in mice treated with IFN-gamma. Using that experimental model, subsequent studies presented evidence showing that the combination of IFN-gamma with 131I-CC49, an anti-TAG-72 MAb, resulted in a statistically significant improvement in therapeutic efficacy when compared with 131I-CC49 alone. For example, treatment with 300 microCi of 131I-CC49 initially suppressed HT-29 tumor growth; however, that reduction in tumor growth was transient as evidenced by the emergence of additional tumor growth at later time points. In contrast, an 8-day treatment with IFN-gamma in combination with 300 microCi 131I-CC49 resulted in sustained suppression of HT-29 tumor growth. Thus, IFN-gamma in vivo can substantially increase the TAG-72 expression in human colon tumor xenografts which leads to an increased tumor localization of anti-TAG-72 MAbs and seems to be responsible for the enhanced antitumor effects when IFN-gamma was combined with 131I-CC49. The results provide further evidence for including a biological response modifier, such as IFN-gamma, which can increase the expression of specific tumor antigens (i.e., TAG-72 and CEA) subsequently leading to a dramatic improvement in the antitumor efficacy of a radionuclide-conjugated MAb.

Animals↗
PubMed1993

Resection margin in patients with gastric cancer associated with esophageal invasion: clinicopathological study.

We investigated the correlations between resection margin involvement by carcinoma and a number of clinicopathological features in patients with gastric cancer and esophageal invasion. From January 1968 to December 1988, 1,040 patients with carcinoma of the stomach underwent gastric resection. Thirty-nine patients had tumor infiltration of the esophagus on histological examination of the resected specimens. The patients were divided into two groups on microscopic examination: those in whom the resection margin was less than 5 mm wide, and those in whom it exceeded 5 mm microscopically. There were 6 and 33 patients in the narrow and wide margin groups, respectively. There were statistically significant differences in tumor size, depth of cancer invasion, and macroscopic appearance between the two groups. The risk of resection margin involvement was high in tumors with the following features: large Borrmann type 4 tumor (macroscopic appearance and size) and infiltrative carcinoma (depth of invasion).

Adenocarcinoma↗
PubMed1993

Anti-ganglioside GD1a monoclonal antibody recognizes senile plaques in the brains of patients with Alzheimer-type dementia.

Immunohistochemical staining of brain tissues from patients with Alzheimer-type dementia (ATD) with an anti-GD1a ganglioside monoclonal antibody is described. This monoclonal antibody labeled some myelinated nerve fibers in brain tissue from a non-demented control subject, in which the staining was distributed preferentially in the cerebral white matter. In brain tissue from ATD patients, some senile plaques (SPs) were also immunostained, with the strongest staining in the hippocampal subiculum, where most of the SPs appeared as clusters of dots. When the immunohistochemical staining was compared with a methenamine silver stain (MS stain), these immunopositive dots were found to be argyrophilic dystrophic (or degenerating) neurites. No amyloid deposits, neurofibrillary tangles (NFTs) or neuropil threads were immunostained. In this study, we used sections cut from formaldehyde-fixed brain samples with a cryostat and pretreatment of the sections with chloroform was essential to obtain positive immunostaining. Gangliosides have been demonstrated to possess some neurotrophic activity and to be localized on cell surface membranes. The localization of the GD1a ganglioside observed in dystrophic neurites suggests that such neurites accumulate a membranous component. In addition, the accumulation of the GD1a ganglioside in SPs suggests it may contribute to SP formation.

Aged↗
PubMed1993

Ontogeny of dopamine transporter mRNA expression in the rat brain.

The ontogeny of dopamine transporter (DAT) gene expression was studied in the rat brain. DAT mRNA was first detected in neurons of the ventrocaudal mesencephalon on embryonic day 14 (E14). By E18, intensely expressing neurons in the ventral tegmental area and substantia nigra resembled the pattern found in adult midbrain. DAT mRNA is not abundant in the hypothalamus and the olfactory bulb at any stage of development. These results parallel those noted for tyrosine hydroxylase gene expression in mesencephalon.

Animals↗
PubMed1993

Non-specific resistance induced by a low-toxic lipid A analogue, DT-5461, in murine salmonellosis.

The ability of DT-5461, a chemically synthetic low-toxic lipid A analogue, to activate anti-Salmonella activity in C3H/HeN mice was examined. Previous intraperitoneal (i.p.) injection of DT-5461 (100 micrograms or more/mouse) significantly hindered the bacterial growth in the peritoneal cavities of the mice after the i.p. infection with Salmonella typhimurium LT2 strain. The effect was the maximum when DT-5461 was given 6 h before the challenge. The injection of DT-5461 6 h in advance could also confer protection against the infection. Bactericidal activity enhancement was also seen in mice that had been injected with a small amount of recombinant murine IFN-gamma (10(3) U per mouse) and non-effective dose (10 micrograms) of DT-5461 together 6 h before the challenge. Bactericidal effect enhancement was seen in mice that had been injected with IFN-gamma at 6 h and DT-5461 at 3 h before the challenge, while it could be hardly seen in mice injected with them in a reversed order. The i.p. injection of DT-5461 recruits the exudate cells into the peritoneal cavities, and the phagocytic and bactericidal abilities of the macrophages in the exudate cells are apparently elevated. The mechanisms of non-specific resistance enhancement induced by DT-5461 were discussed.

Adjuvants, Immunologic↗
PubMed1993

Effects of high-molecular-weight hyaluronates on the functions of guinea pig polymorphonuclear leukocytes.

The effect of hyaluronate (HA) with a molecular weight of 1,900,000 (HA190) purified from products of Streptococcus equi on various functions of guinea pig peritoneal polymorphonuclear leukocytes (PMNs) was examined. HA190 effectively inhibited both the chemotactic activity of PMNs for a chemotactic peptide, formyl-Met-Leu-Phe, and the phagocytic activity of the cells for serum-opsonized zymosan (SOZ) in a dose-dependent manner. When the inhibitory activity of the HAs of different molecular weights, including HA190, HA of molecular weight 800,000 (HA80), and HA of molecular weight 300,000 (HA30), was assessed, the HA190 showed the strongest inhibitory activity and HA30 the lowest activity. In contrast, significant inhibition of the superoxide generation by PMNs upon stimulation with SOZ was not observed even in the presence of HA190 and HA80 at the highest concentration used (2.5 mg/mL). This finding indicated that the HAs studied did not prevent the interaction of PMNs with stimuli. From these data it is concluded that the binding of high-molecular-weight HAs to the HA receptors on PMNs may produce intracellular signals that are responsible for suppression of phagocytosis and chemotaxis but not for superoxide generation.

Animals↗
PubMed1993

Serum levels of intercellular adhesion molecule-1 in patients with alcoholic liver disease.

Serum levels of intercellular adhesion molecule-1 (ICAM-1) were measured in 37 patients with alcoholic liver disease, six alcoholics without liver disease and ten healthy subjects. The serum level of ICAM-1 was significantly higher in the patients with alcoholic cirrhosis than in the noncirrhotic alcoholic liver disease patients (P < 0.005) and the healthy subjects (P < 0.001). Furthermore, the serum level of ICAM-1 was significantly higher in the patients with alcoholic hepatitis than in those with alcoholic cirrhosis (P < 0.001). No significant difference in serum ICAM-1 levels was found between normal subjects and alcoholics without liver diseases. In the patients with alcoholic hepatitis, serum levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) derived from macrophages were increased in the presence of endotoxemia. The increase in serum ICAM-1 may therefore be related to the strong expression of ICAM-1 of hepatocytes and endothelial cells accompanied by the increase in serum TNF-alpha.

Adult↗