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Biomedical subjects

S Hirota

Publications and source records attributed to S Hirota.

At least 127 records · Page 7Linked to original sources

Effect of CPT-11 on lipid peroxide level in mouse tissues.

We examined the effects of CPT-11 on lipid peroxide level and glutathione peroxidase (GSHpx) activity as indices of the toxicity of this antitumor agent in mouse and rat tissues. After CPT-11 (100 mg/kg, i.p.) administration, the lipid peroxide level in the heart increased 1.5 fold (mice) and 1.3 fold (rats) over the control levels. GSHpx activity decreased to 64% of the control. In the lung, the lipid peroxide level and GSHpx activity increased 2.5 fold and decreased to 74% after CPT-11 administration, respectively, compared with the control values. These results suggested that CPT-11 may cause cardiotoxicity and pulmotoxicity. In rat bone marrow, the lipid peroxide level increased on the 2nd day after CPT-11 injection. We suggest that in both single and combination treatment with CPT-11, the possibility of side effects should be taken into consideration.

Animals↗

[An importance of colloid chemical characterization of liposomes for DDS in a large scale production].

Efficacy and safety data of liposomal drugs in a laboratory environment are often not reproduced on an industrial production scale. This is largely due to the fact that the colloid-chemical properties of the liposomes manufactured on a small scale are not reproduced in large scale production. Though the size and the electric charge of liposomes are measured and are adequately specified in relation to the bio-distributions in most developments of liposomes (1), uniformity of lipid components, exposure of bio-chemically important functional groups on the outer surface of liposomes (2), fixed aqueous layer thickness (FALT), number of the lipid bilayers, etc., are dependent upon the scale of production. Nevertheless these properties are not always exactly specified. Uniformity, especially of the functional groups on the membrane surface can be assessed chemically or bio-chemically with fractionated samples, and FALT can be easily determined through electro-chemical means (3). In this review, colloid chemical characterization of liposomes is introduced, FALT as an example, and its importance in a quality control of a liposomal product in an industrial scale production is shown. Methoxy-polyethyleneglycol-diacylglycerol (PEG-DAG) with varying PEG chain length and acyl chains were synthesized, FALT of liposomes coated with PEG-DAG determined and tissue distribution in tumor bearing mice. The higher incorporation ratio of PEG-DAG into liposomal membrane was observed with PEG-DAG with short acyl chains (myristoyl) and a small PEG molecular weight (1000). The easier to incorporate, the easier to be stripped in the serum. The disposition data in the rats well reflected the colloid chemical and in vitro data of the PEG liposomes. Galactosyl-carbonyl-propionyl-polyethyleneglycol-diacylglycerol (Gal-PEG-DAG) with oxyethylene number, n = 10, 20 and 40 were synthesized. The exposure of the galactose residue beyond the fixed aqueous layer of liposomes coated with Gal-PEG-DAG was monitored by a lectin, Ricinus communis agglutinin (RCA) induced agglutination, the half life in the blood after i.v. injection into rats, organ distribution determined and intrahepatic distribution studied. Only the liposomes containing the Gal-PEG10-DAG aggregated with the lectin, indicating that only with this derivative the galactose group was adequately exposed. The Gal-PEG10-DAG liposomes were cleared from the plasma with a half life of 0.3 h. The plasma elimination could be attributed entirely to increased uptake by the liver. The increased liver uptake was almost entirely attributed to increased uptake by the non-parenchymal cell. Incorporation of PEG-DSPE in to the Gal-PEG10-DAG liposomes caused 1) a three-fold increase in blood circulation time, 2) a small but significant decrease in hepatic uptake after 20 h and 3) a significant shift in intrahepatic distribution in favor of the hepatocytes, comparable to that of the control liposomes. In conclusion, therapeutic efficacy and safety of liposomes can be controlled by their colloid chemical, more exactly, surface chemical properties. By setting up reasonable quality control specification of the properties in laboratory and examining the specifications satisfied in upscaling, the efficacy and safety are reproduced in a large scale product.

Animals↗

Deficiency of c-kit+ cells in patients with a myopathic form of chronic idiopathic intestinal pseudo-obstruction.

OBJECTIVES: Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a syndrome characterized by a failure of intestinal movement, but the cause of dysmotility remains unknown. Because interstitial cells of Cajal (ICCs) are believed to initiate basic contractile activity of the gastrointestinal tract, there is a possibility that changes in ICCs are involved in the development of CIIP. ICCs express c-kit in mice, and it has been reported that the c-kit+ cells, the location and shape of which resemble those in mice, are detected in the human gastrointestinal muscular layer using immunohistochemistry. In the present study, we counted the number of c-kit+ cells in the affected intestine of two patients with myopathic form of CIIP and compared this number with the number of c-kit+ cells in the normal intestine. METHODS: The c-kit+ cells in the external muscle layer were detected by immunohistochemistry, and the number of them was counted under the microscope. Mast cells, which are known to express c-kit, were detected by staining with Alcian blue, and the number of them was also counted. RESULTS: Immunohistochemistry revealed that the distribution pattern of c-kit+ cells resembles that of ICCs in the external muscle layer of normal control subjects. The numbers of c-kit+ cells apart from mast cells in two patients with myopathic form of CIIP decreased to about 3% of those in normal subjects. CONCLUSIONS: The failure of intestinal movement in patients with CIIP, at least in a subpopulation, might be related to a deficiency of c-kit+ cells, probably ICCs.

Adult↗

Treatment of metastatic liver tumors by intermittent repetitive injection of an angiogenesis inhibitor using an implantable port system in a rabbit model.

Angiogenesis inhibitors are expected as a new type of anticancer drug, because they may prevent tumor neovascularization. Among several angiogenesis inhibitors, 6-o-(N-chloroacetylcarbamoyl)-fumagillol (TNP-470) is thought to inhibit the proliferation of migrating endothelial cells, as an aspect of angiogenesis, and attracts an attention for clinical application. We attempted to evaluate anticancer effects of intermittent repetitive intraportal injection of TNP-470 for metastatic liver tumor models and considered the usefulness and a role as an angiogenesis inhibitor, TNP-470, in the anti-cancer therapy using an implantable port system. We used 25 Japanese white rabbits with metastatic liver tumors made by intraportal injection of tumor cells (VX2-carcinoma), and divided those into five groups; group A was control group, group B was treated by repetitive subcutaneous injection of TNP-470 and group C, D, E was treated by repetitive intraportal injection of TNP-470, adriamycin, TNP-470 + adriamycin respectively 5 times at 2 or 3 days interval after tumor inoculation using implantable port systems. After 2 weeks, we evaluated anti-cancer effect of TNP-470 pathologically. In the number of grown tumors, there was no difference among five groups statisitically. But the mean tumor size of each group is smaller in order of group E, D, C, B, A and the differences were significant (P < 0.05) except between E and D group. And intratumoral neovascularization tended to be less in group B, C, E than in group A, D pathologically. We consider that intermittent repetitive injection of TNP-470 is more useful than systemic administration for metastatic liver tumors and the administration of angiogenesis inhibitor with other anti-cancer agents via an implantable port system will be one of the most effective therapeutic methods for them.

Animals↗

[Radiation therapy for adrenal metastases].

PURPOSE: To evaluate the role of radiation therapy for adrenal metastases. MATERIALS AND METHODS: Fourteen patients, 13 with primary lung carcinoma and one with primary unknown carcinoma, received radiation therapy for adrenal metastases from 1984 to 1995 at the Hyogo Medical Center for Adults. Total dose ranged from 16 Gy to 60 Gy, and fractional dose from 1.6 Gy/ Fr to 3 Gy/Fr. RESULTS: Partial response of the local tumor was recognized in 2 of 7 patients by CT imaging. Pain relief was obtained in 7 of 8 patients. Median survival was 3 months, and 6-month survival was 28.6% in all patients. Among patients in the symptomatic group, who had complaints of pain due to adrenal mass, survival was even worse (12.5% at 6 months). There were no severe complications, but 4 patients (29%) had gastrointestinal symptoms. CONCLUSION: Radiation therapy is useful for the purpose of pain relief in adrenal metastases.

Adrenal Gland Neoplasms↗

Absence of mast cell involvement in leukocyte adhesion and emigration induced by inhibition of nitric oxide synthase.

Leukocyte adhesion on venules and their emigration to extravascular connective tissue are induced by administration of a nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester. In the present study, the involvement of mast cells in the process was examined in genetically mast cell-deficient and normal rats by intravital microscopy. Superfusion of the NOS inhibitor into the mesentery induced partial degranulation of mast cells in normal rats. However, leukocyte adhesion on mesenteric venules and emigration to extravascular connective tissue occurred even in mast cell-deficient rats, with no significant difference from the normal rats. When the reverse-passive Arthus reaction, characterized by generalized antigen-antibody complex formation, was induced in the rat mesentery, the immune complex increased both the adhesion and emigration in normal rats but not in mast cell-deficient rats. These results show that mast cells are not involved in the leukocyte adhesion and emigration induced by NOS inhibition, but are in the reverse-passive Arthus reaction.

Animals↗

Ectopic bone formation after total hip arthroplasty.

Two hundred and forty consecutive Japanese patients with 280 primary total hip arthroplasties (THA) were analyzed to clarify the incidence of ectopic bone formation and its predisposing factors and to examine its effect on the clinical results. Ectopic bone formation after THA was found in 61 joints (22%). The predisposing factors were male patients and a hypertrophic type of osteoarthritis. It was revealed that extensive ectopic bone formation, class 3 according to Brooker's classification, restricted flexion and abduction motion of the hip joint.

Adult↗

[Analysis of in-field and marginal relapse in stage I/II non-Hodgkin's lymphoma treated with radiotherapy].

One hundred sixty-three patients with previously untreated stage I/II non-Hodgkin's lymphoma were analyzed as to their in-field and marginal relapse of the irradiated field following treatment with more than 30 Gy of radiotherapy between 1981 and 1995 at Hyogo Medical Center for Adults. Local regrowth in case of partial response was counted as in-field relapse. Complete response was obtained in 94.5% of the cases at the termination of radiotherapy and in 98.8% finally. The ten-year cumulative in-field relapse and marginal relapse rates were 5% and 8.7%, respectively. The cumulative in-field relapse rate (CIFRR) in cases of bulky disease (more than 5 cm in largest diameter of the tumor) was significantly higher than in those of non-bulky disease (26.1% in 8 years vs 2.4% in 10 years, P < 0.01). The radiation dosage delivered (40 Gy = < and 50 Gy > vs 50 Gy < =) a great much difference in cases of bulky disease (23.8% for 8-year CIFRR vs 0% for 1-year CIFRR, respectively), but less difference with non-bulky disease (2.6% vs 2.2%). High LDH and suboptimal dose chemotherapy (three courses and less chemotherapy containing ADM or its derivatives, chemotherapy without ADM or no chemotherapy) had a negative impact on marginal control in aggressive lymphoma. Extended field setting in aggressive lymphoma was not proven to be beneficial in comparison with involved field setting as to marginal field relapse. Thus, it is concluded that (1) higher doses should be given to bulky disease, (2) careful field coverage with enough margin is recommended for aggressive lymphoma with high LDH or treated without optimal dose chemotherapy, and (3) extended field setting is not necessary.

Adolescent↗

[Radiotherapy for adenocarcinoma of the uterine cervix].

One hundred three patients with adenocarcinoma of the uterine cervix treated with radiotherapy between 1975 and 1992 were evaluated. The results for 24 patients treated with radiotherapy alone were as follows: The overall 5-year survival rates for Stages I + II (N = 12) and III + IV (N = 12) were 52% and 16%, respectively, lower than those for squamous cell carcinoma (stage I: 89%, II: 54%, III: 44%, IV: 19%). The overall response rate was 79.1%, and the recurrence rate was 54.2% (local recurrence: 29.2%, distant metastasis: 33.3%). In Stage I + II patients with an intracavitary irradiation dose of 40 Gy (LDR) or more, there was no local recurrence. In stage III + IV patients, local recurrence was recognized in spite of the high dosage of intracavitary irradiation. The results for 79 patients treated with combined irradiation and operation were as follows: The overall 5-year survival rates for Stages I, II, III and IV were 76%, 60%, 57%, and 0%, respectively. The incidence of lymph node metastasis was 30.4%, and for Stages I, II, III and IV was 26.7%, 34.6%, 28.6%, and 100%, respectively. This showed that adenocarcinoma had a higher incidence of lymph node metastasis after the early stage. The recurrence rate for patients with lymph node metastasis was 75.0%, significantly higher than 25.4% for patients without lymph node metastasis (p < 0.001). To improve prognosis, 40 Gy or more of intracavitary irradiation dose (LDR) and systemic chemotherapy to prevent distant metastasis are recommended for stage I and II cases. For stage III and IV cases, it was thought to be difficult to control local disease with radiation alone. Additional treatment should be used for these cases, i.e. intraarterial infusion, chemotherapy, hyperthermia and so on.

Adenocarcinoma↗

Effect of sterical stabilization on macrophage uptake in vitro and on thickness of the fixed aqueous layer of liposomes made from alkylphosphocholines.

A serious problem using liposomes for therapeutic purposes is the fast removal from blood circulation by components of the reticuloendothelial system (RES) most likely after opsonization of the vesicles. This study was performed to quantify the reduction in macrophage uptake in vitro of sterically stabilized liposomes (PEG-liposomes) prepared from hexadecylphosphocholine, cholesterol and poly(ethylene glycol2000) distearoylphosphoethanolamine (PEG2000DSPE) for the first time. The uptake was determined using HPC-liposomes of different defined size (125, 250 and 1000 nm) without and with sterical stabilization by incorporating 5 mol% of PEG2000DSPE. HPTS was used as fluorescence marker allowing the discrimination between general uptake and the part of liposomes internalized into the low pH-compartment (Daleke, L.D., Hong, K. and Papahadjopoulos. D. (1990) Biochim. Biophys. Acta 1024, 352-366). Liposomal uptake by J774 mouse macrophage-like cells was time-dependent. Both the uptake and internalization were clearly reduced for PEG-liposomes compared to plain liposomes. Sterical stabilization reduced the general uptake of liposomes in vitro by more than 50% and the internalization by about 50-60%. PEG-liposomes additionally showed a delay in internalization into the macrophages during the first 6 h. Size of used liposomes had only a minor influence on liposomal uptake but highest concentration of lipid was found for large multilammelar vesicles (MLV). The fixed aqueous layer thickness (FALT) was determined by zeta potential measurements of plain and sterically stabilised HPC-liposomes (100 nm) in solutions of different ion concentrations. The calculation of the thickness was based on the linear correlation between ln zeta (zeta-potential) and kappa (Debye Hückel-Parameter). FALT was calculated and found to be for plain HPC-liposomes 0.83 +/- 0.17 nm and for PEG-HPC-liposomes 3.57 +/- 0.17 nm. Exchange of the HPC by an alkylphospholipid with different head group has no or only minor effect (PEG-OPP-liposomes 3.44 +/- 0.31 nm). Thus the reduced uptake of HPC-LUVET correlates with an increased thickness of the fixed aqueous layer around these liposomes and could support the hypothesis that the thickness is an important property responsible for preventing opsonization and resulting finally in a reduced macrophage uptake.

Animals↗

150-kD oxygen-regulated protein is expressed in human atherosclerotic plaques and allows mononuclear phagocytes to withstand cellular stress on exposure to hypoxia and modified low density lipoprotein.

The 150-kD oxygen-regulated protein (ORP150) was initially characterized based on its selective expression in astrocytes subjected to oxygen deprivation (Kuwabara, K., M. Matsumoto, J. Ikeda, O. Hori, S. Ogawa, Y. Maeda, K. Kitagawa, N. Imuta, K. Kinoshita, D.M. Stern, et al. 1996. J. Biol. Chem. 279:5025-5032). We have found that exposure of cultured human aortic smooth muscle cells and mononuclear phagocytes (MPs) to hypoxia (pO2 approximately 12-14 torr) induces ORP150 transcripts and production of the antigen, whereas incubation with either hydrogen peroxide, sodium arsenite, heat shock, or 2-deoxyglucose was without effect. Tissue extracts prepared from human atherosclerotic lesions demonstrated expression of ORP150 mRNA and antigen, vs lack of ORP150 in samples from nonatherosclerotic areas. In situ hybridization using ORP150 riboprobes showed the mRNA to be predominantly [correction of predominately] present in macrophages in in atherosclerotic plaques. Furthermore, autoantibody to ORP150 was demonstrated in the serum of patients with severe atherosclerosis, consistent with inducible in vivo expression of ORP150. Introduction of antisense oligonucleotide for ORP150 selectively diminished hypoxia-mediated induction of ORP150 antigen and reduced the viability of hypoxic MPs, especially in the presence of modified (oxidized/acetylated) LDL. In support of a role for ORP150 in the MPs' response to the microenvironment of an atheroma, the presence of oxidized LDL enhanced by approximately 10-fold ORP150 expression in hypoxic cultures. These data indicate that cells of the atherosclerotic vessel wall express ORP150 as part of a protective mechanism, potentially triggered by local hypoxia/hypoxemia and augmented by modified lipoproteins. The presence of antibody to ORP150 in sera of patients with severe atherosclerosis emphasizes the possibility that ORP150 may be a marker of vascular pathology.

Adolescent↗

Defects of B-cell lymphopoiesis and bone-marrow myelopoiesis in mice lacking the CXC chemokine PBSF/SDF-1.

The chemokines are a large family of small, structurally related cytokines. The physiological importance of most members of this family has yet to be elucidated, although some are inducible inflammatory mediators that determine leukocyte chemotaxis. Pre-B-cell growth-stimulating factor/stromal cell-derived factor-1 (PBSF/SDF-1) is a member of the CXC group of chemokines PBSF/SDF-1 stimulates proliferation of B-cell progenitors in vitro and is constitutively expressed in bone-marrow-derived stromal cells. Here we investigate the physiological roles of PBSF/SDF-1 by generating mutant mice with a targeted disruption of the gene encoding PBSF/SDF-1. We found that mice lacking PBSF/SDF-1 died perinatally and that although the numbers of B-cell progenitors in mutant embryos were severely reduced in fetal liver and bone marrow, myeloid progenitors were reduced only in the bone marrow but not in the fetal liver, indicating that PBSF/SDF-1 is responsible for B-cell lymphopoiesis and bone-marrow myelopoiesis. In addition, the mutants had a cardiac ventricular septal defect. Hence, we have shown that the chemokine PBSF/SDF-1 has several essential functions in development.

Animals↗

The effects of theanine, as a novel biochemical modulator, on the antitumor activity of adriamycin.

We studied the effects of theanine, a component of green tea leaves, on the antitumor activity of adriamycin (ADR) from the biochemical modulation view point. In vitro, theanine inhibited the ADR efflux from Ehrlich ascites carcinoma cells and maintained the ADR concentration in tumor cells. Theanine enhanced the inhibitory effect of ADR on tumor growth by 2.1-fold in vivo, and increased 2.9-fold the ADR concentration in the tumor, compared to the ADR alone group. An increase in ADR concentration was not observed in normal tissues, such as the heart and liver. Theanine did not enhance, rather tended to normalize the increase of lipid peroxide level and reduction of glutathione peroxidase activity as indicators of the ADR-induced side toxicity.

Animals↗

Two amine oxidases from Aspergillus niger AKU 3302 contain topa quinone as the cofactor: unusual cofactor link to the glutamyl residue occurs only at one of the enzymes.

Amine oxidases (EC 1.4.3.6) from Aspergillus niger, AO-I (2 x 75 kDa) and AO-II (80 kDa), were examined to determine the cofactor structure. Inactivated with p-nitrophenylhydrazine, they showed absorption and fluorescence spectra similar to those published for other copper amine oxidases and to topa hydantoin p-nitrophenylhydrazone. After digestion by thermolysin and pronase, cofactor peptides were purified by HPLC and sequenced. For thermolytic peptides, a typical topa consensus sequence, Asn-X-Glu-Tyr, was obtained for AO-II, although in case of AO-I it overlapped with Val-Val-Ile-Glu-Pro-Tyr-Gly. For pronase peptides of AO-I, only the latter sequence was obtained. NMR and mass spectroscopy confirmed the residue X as topa p-nitrophenylhydrazone in AO-II and revealed the presence of a residue Z attached to the Glu in the peptide Val-Val-Ile-Glu(Z)-Pro of AO-I. This residue was separated from the peptide by hydrolysis and identified as a product derived from topa quinone. The data, together with amino-acid sequence of AO-I, confer strong evidence for topa quinone as the cofactor, bound in the typical consensus sequence. Raman spectra of the p-nitrophenylhydrazone derivative of AO-I and its pronase peptide showed essentially the same peaks matching to a model compound for topa p-nitrophenylhydrazone. However, there may exist an unusual ester link between the topa-404 and Glu-145 in the native enzyme.

Amine Oxidase (Copper-Containing)↗

Percutaneous hepatic venous isolation and extracorporeal charcoal hemoperfusion for high-dose intraarterial chemotherapy in patients with colorectal hepatic metastases.

The results of treating 12 consecutive patients with unresectable colorectal hepatic metastases with a hepatic arterial infusion of high-dose Adriamycin, 100-120 mg/m2, using hepatic venous isolation (HVI) and charcoal hemoperfusion (CHP) are reported herein. Adriamycin was administered over 5-15 min under extracorporeal drug elimination by HVI-CHP. HVI was percutaneously accomplished by either the double-balloon technique using a Fogarty occlusion catheter (8/22F) or a balloon-tipped catheter (16F). During the infusion, isolated hepatic venous blood was filtered by CHP and pumped into the left axillary vein. There were no lethal complications, and good hemodynamic tolerance to HVI-CHP was confirmed. Tumor liquefaction accompanied by a sharp decrease in serum carcinoembryonic antigen levels by more than 50% of pretreatment levels was observed in 6 of the 12 patients 1 month after treatment. Apart from chemical hepatitis, which developed in 11 (92%) of the patients, the Adriamycin toxicities were well controlled following the development of nausea and vomiting in 2 patients (17%), leukopenia < 2,000/mm3 in 3 (25%), and gastric ulcer in 1 (8%). These results indicate that this method is a safe and useful procedure for otherwise hazardous high-dose intra-arterial chemotherapy in patients with unresectable hepatic tumors.

Adult↗

A flash-photolysis study of the reactions of a caa3-type cytochrome oxidase with dioxygen and carbon monoxide.

The time course of absorbance changes following flash photolysis of the fully-reduced carboxycytochrome oxidase from Bacillus PS3 in the presence of O2 has been followed at 445, 550, 605, and 830 nm, and the results have been compared with the corresponding changes in bovine cytochrome oxidase. The PS3 enzyme has a covalently bound cytochrome c subunit and the fully-reduced species therefore accommodates five electrons instead of four as in the bovine enzyme. In the bovine enzyme, following CO dissociation, four phases were observed with time constants of about 10 microseconds, 30 microseconds, 100 microseconds, and I ms at 445 nm. The initial, 10-microsecond absorbance change at 445 nm is similar in the two enzymes. The subsequent phases involving heme a and CuA are not seen in the PS3 enzyme at 445 nm, because these redox centers are re-reduced by the covalently bound cytochrome c, as indicated by absorbance changes at 550 nm. A reaction scheme consistent with the experimental observations is presented. In addition, internal electron-transfer reactions in the absence of O2 were studied following flash-induced CO dissociation from the mixed-valence enzyme. Comparisons of the CO recombination rates in the mixed-valence and fully-reduced oxidases indicate that more electrons were transferred from heme a3 to a in PS3 oxidase compared to the bovine enzyme.

Animals↗

Inhibition of histamine synthesis by glycyrrhetinic acid in mast cells cocultured with Swiss 3T3 fibroblasts.

The effect of glycyrrhetinic acid (18-O-beta-glycyrrhetinic acid, GA) on histamine metabolism was investigated in cultured mast cells (CMCs) cocultured with Swiss 3T3 fibroblasts. GA strongly inhibited histamine synthesis in the cocultured CMCs. Since 50 microM GA inhibited about 80% of histidine decarboxylase (HDC) activity, the inhibitory activity of GA for histamine synthesis was considered to be derived from the inhibition of HDC activity. The number of berberine-sulfate-positive cells also decreased in the presence of GA, which indicated that maturation of CMCs was inhibited by GA. Furthermore, we examined the effect of GA on the mRNA expression of novel protein kinase C delta (nPKC delta), a major isoform of CMCs, by northern blot analysis. The expression of nPKC delta mRNA in the presence of GA was significantly lower than in the absence of GA. These results suggest the possibility that the inhibition of histamine synthesis by GA is regulated by nPKC delta.

3T3 Cells↗