Biomedical subjects

T Kawaguchi

Publications and source records attributed to T Kawaguchi.

At least 19 recordsLinked to original sources

PubMed1992

Specific binding sites for 125I-endothelin-1 in the porcine and human spinal cord.

Specific binding sites for 125I-endothelin-1 (125I-ET-1) in the spinal cord were investigated using quantitative receptor autoradiographic and chemical cross-linking methods. The binding sites were highly concentrated in porcine and human spinal cord areas corresponding anatomically to the dorsal horn (Rexed's laminae I-III), an area around the central canal (lamina X) and the principal part of the intermediolateral nucleus (IMLp). The localization of the binding sites differed from those of 125I-omega-conotoxin GVIA (125I-CgTx) and 125I-Bolton-Hunter substance P (125I-BH-SP), with the exception that the IMLp shared 125I-ET-1 with 125I-CgTx and 125I-BH-SP binding sites. Specific 125I-ET-1 binding sites in the areas examined were characteristically single and of high affinity. There were no differences between the potencies of unlabeled ET family peptides, ET-1, ET-2, ET-3 and sarafotoxin S6b at inhibiting 125I-ET-1 binding to the areas. Chemical cross-linking studies showed that 125I-ET-1 and 125I-ET-3 mainly bound to a protein with molecular mass of 43 kDa in the porcine and human thoracic spinal cord membranes. The present finding shows the neuronal significance of this newly discovered peptide in the spinal cord.

Aged↗

PubMed1992

Antitumor effects of SMANCS on rat mammary tumor induced by 7,12-dimethylbenz[a]anthracene.

We previously found that a high-molecular-weight anticancer agent, polystyrene-co-maleic acid conjugated neocarzinostatin (SMANCS), in which two chains of styrene/maleic acid copolymer are conjugated to the anticancer protein neocarzinostatin (NCS), accumulated more selectively in tumor tissue than in normal tissue and was more stable than NCS in blood. These results indicate that SMANCS should have less systemic toxicity and a better therapeutic effect than NCS. In this study, the antitumor activity and adverse effects of SMANCS were compared with those of NCS by using rat mammary tumor induced by 7,12-dimethylbenz[a]anthracene. When tumors of rats, that had received 7,12-dimethylbenz[a]anthracene (20 mg/kg, one dose, p.o. in oily formulation), became palpable usually after 4-20 weeks, SMANCS treatment was initiated. Thirty days after i.v. administration of SMANCS (0.1 mg/kg 3 times and 0.3 mg/kg 3 times), tumors had shrunk in 35 of 37 rats (a mean weight was about 10% of control value; or decreased to about 30% of the value of before treatment in tumor weight); tumor size had not changed in 1 rat, and in the remaining 1 rat the tumor had enlarged. Thirty days after i.v. administration of NCS, tumors had shrunk in 8 of 14 rats, but the tumor size was unchanged in 1 rat and was enlarged in 5. In the control group, all tumors had enlarged. Development of new tumors was completely prevented by the administration of SMANCS. Histological examination of sequential slices of tumor revealed clear finding of degeneration and tumor encapsulation at 30 days after initial administration of SMANCS, with an accompanying fatty degeneration, but these effects were not observed for tumors treated with NCS. Although red blood cell counts and hemoglobin amounts decreased significantly in rats receiving NCS, no such effects were apparent in the SMANCS group.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1992

Induction of Mn-superoxide dismutase by tumor necrosis factor, interleukin-1 and interleukin-6 in human hepatoma cells.

Effects of Tumor Necrosis Factor (TNF), Interleukin-1 (IL-1), Interleukin-6 (IL-6) and Interferon-gamma (IFN-gamma) on the expression of Mn-superoxide dismutase (Mn-SOD) protein were investigated in human hepatoma cells, Hu-H1, which revealed resistance to the cytotoxicity of TNF and IL-1. Both TNF and IL-1 enhanced the Mn-SOD production to the level of 30- to 40-fold. IL-6 also increased the enzyme protein to 2- to 3-fold of the basal level without any cell proliferative effect. A specific antibody against IL-6 almost completely inhibited the induction of Mn-SOD. IL-6, as well as TNF and IL-1, appears to play some role in the Mn-SOD protein expression in human hepatoma cells.

Antibodies↗

PubMed1992

Anticancer effects of free polyunsaturated fatty acids in an oily lymphographic agent following intrahepatic arterial administration to a rabbit bearing VX-2 tumor.

The anti-hepatic cancer effects of three free polyunsaturated fatty acids (linoleic, alpha-linolenic, and gamma-linolenic acids) dissolved in an oily lymphographic agent, Lipiodol Ultra-Fluid (Lipiodol), following intrahepatic arterial administration were examined using a rabbit liver cancer model, VX-2. The tumor was inoculated into the subcapsular parenchyma of the liver of rabbits, and Lipiodol alone or Lipiodol containing each one of the free fatty acids was administered into the hepatic artery 14 days after inoculation. The rabbits were sacrificed 7 days after administration. Lipiodol containing one of the fatty acids selectively remained in the tumor area. Although VX-2 tumor grew extensively in both the untreated group and the group that received Lipiodol alone, growth of VX-2 tumor was greatly suppressed in the group that received Lipiodol containing the free fatty acid. Pathological observation also showed that Lipiodol containing the free fatty acid had an anticancer effect on VX-2 tumor growing in the liver of rabbits. Average survival days in the group treated with Lipiodol containing gamma-linolenic acid were significantly prolonged compared with those in the control groups. Although growth rates of the tumor at the death of rabbits were large in the control groups, VX-2 tumor shrank at death of five rabbits of six in the group treated with Lipiodol containing gamma-linolenic acid. These results suggest that the intrahepatic arterial administration of Lipiodol containing the free fatty acids is an effective method of delivery of these fatty acids as anticancer agents.

Animals↗

PubMed1992

Control of drug release with a combination of prodrug and polymer matrix: antitumor activity and release profiles of 2',3'-diacyl-5-fluoro-2'-deoxyuridine from poly(3-hydroxybutyrate) microspheres.

Drug release was controlled by a combination of prodrug and polymer matrix. Prodrugs of 5-fluoro-2'-deoxyuridine with different physicochemical properties were synthesized by esterification with aliphatic acids (propionate, n-butyrate, and n-pentanoate). Microspheres containing these ester prodrugs were prepared with poly(3-hydroxybutyrate) of three molecular weights (65,000, 135,000, and 450,000). The release rates from the spheres depended on both the lipophilicity of the prodrug and the molecular weight of the polymer. Regardless of the polymer, the relative release rates were propionate greater than butyrate greater than pentanoate. The release of butyrate and pentanoate from the spheres consisting of low-molecular-weight polymer (M(r), 65,000) was faster than that from the spheres of higher molecular weight (M(r), 135,000 or 450,000). A single intraperitoneal injection of spheres of the highest molecular weight polymer containing butyrate or pentanoate resulted in higher antitumor effects against P388 leukemia in mice than did free prodrugs given over a period of five consecutive days. The polymer sphere itself showed low toxicity to and good biocompatibility with mice and rats.

Animals↗

PubMed1992

Substrate adhesiveness and experimental metastatic potential of rat ascites hepatoma AH7974-derived variant sublines.

Cells of an adherent subline (74AD, adhesion greater than 95%) and a floating subline (74FL, adhesion less than 1%) of rat ascites hepatoma AH7974 produced substrates containing fibronectin (FN), laminin (LN) and type IV collagen (CL-IV), with 74AD cells producing higher levels of each component. 74AD cells possessed high adhesion affinities to LN and CL-IV substrates. By contrast, 74FL cells hardly adhered to these purified attachment proteins. The difference in adhesion between the two lines in vitro tended to increase on incubation of the cells in medium containing fetal bovine serum. However, 74FL and 74AD cells adhered avidly to the extracellular matrix (ECM) of vascular endothelial cells. Although the cell-ECM adhesion apparently was not inhibited by pretreatment of the ECM with anti-FN, anti-LN and anti-CL-IV antibodies, the 74FL cell-ECM adhesion was inhibited considerably by pretreatment of the ECM with a mixture of these antibodies, especially with a combination of anti-FN and anti-LN antibodies. The lung-colonizing potential of 74FL cells was greater than that of 74AD cells, but the liver-colonizing potential of 74FL cells was less than that of 74AD cells. These results suggest that rat ascites hepatoma cells with extremely reduced substrate adhesiveness retain an adhesion mechanism that binds to FN and LN in the ECM of vascular endothelial cells. This mechanism may be a minimum essential unit of tumor cell-ECM adhesion in lung colonization, but the unit is insufficient for liver colonization of these cells.

Animals↗

PubMed1992

Ganglioside-induced inhibition of in vivo immune response in mice.

In vitro immunomodulatory properties of gangliosides have been well characterized such as the ganglioside-induced modulation of CD4 on T lymphocytes and inhibition of lectin-induced proliferative response of lymphocytes. These findings have led to an interesting suggestion that gangliosides play a role as in vivo immune modulators, although this possibility is not clearly defined yet. We then first confirmed in vitro effects of gangliosides on murine immunocytes and examined in vivo effects of gangliosides on immune response in mice. Murine spleen cells that were treated with a ganglioside mixture (GS) purified from bovine brain exhibited a marked decrease in CD4 expression, while CD8 expression was slightly suppressed. Transplantation of GS-untreated control immunocytes that were isolated from syngeneic mice into the immune suppressed mice by X-ray irradiation restored in vivo immune responses, while GS-treated cells could not. Immune response was assayed by the evaluation of footpad swelling which was induced by immunization with sheep erythrocytes as antigens. Moreover, intramuscular administration of gangliosides into mice suppressed both immediate (Arthus)-type and delayed-type allergic reactions. These results suggest that gangliosides would be potential in vivo immune modulators.

Animals↗

PubMed1992

Antibody to hepatitis C virus in patients with chronic schistosomiasis.

To clarify the effect of hepatitis C virus (HCV) infection in patients with chronic schistosomiasis, 96 patients with schistosomiasis and 137 patients with chronic liver disease without schistosomal infection were analysed by domination of antibody to HCV (anti-HCV). In 45 of 96 schistosomiasis patients, the serum alanine aminotransferase (ALT) level was continuously elevated, and the positive rate of anti-HCV was 52.9%, which is almost the same prevalence rate as in patients with chronic liver disease (48.9%). In contrast, in the remaining 51 schistosomiasis patients, serum ALT level was continuously within the normal range and the positive rate of anti-HCV was 0%. Histological investigation showed that the positive rate of anti-HCV in HBsAg-negative schistosomiasis patients was 14% for hepatic fibrosis, 71% for chronic hepatitis, 80% for liver cirrhosis and 56% for hepatocellular carcinoma. In all anti-HCV-positive patients, serum ALT level was continuously elevated. The serum transaminase levels in anti-HCV-positive patients were higher than those in anti-HCV-negative patients. These data suggest that in patients with chronic schistosomiasis, HCV infection accelerates the derangement of liver function, and may be a major aetiological factor in the development of chronic hepatitis and liver cirrhosis, supporting a causative association between HCV infection and hepatocellular carcinoma.

Aged↗

PubMed1992

A combined small cell and spindle cell carcinoma of the lung. Report of a unique case with immunohistochemical and ultrastructural studies.

A unique bronchial tumor is reported. The tumor grew as an endobronchial polyp and obstructed the right main bronchus. Histologically the lesion consisted of two different types of neoplastic cells; epithelial small cell nests and atypical spindle-shaped cells. Immunohistochemical studies with a panel of antibodies showed that the small cell nests were immunoreactive for epithelial and neuroendocrine markers. The spindle-shaped cells showed positive staining for smooth muscle actin. Epithelial markers were also positive focally in the spindle cells. Electron microscopy confirmed that the spindle-shaped cells had both epithelial and mesenchymal features. Based on these results, the tumor was considered to be a unique combination of small cell and spindle cell carcinoma.

Carcinoma↗

PubMed1992

Sequence diversity of the 1.3 kb retron (retron-Ec107) among three distinct phylogenetic groups of Escherichia coli.

In the preceding paper, we showed that a new 1.3 kb retron (retron-Ec107) in Escherichia coli is responsible for the biosynthesis of a branched-RNA-linked multicopy single-stranded DNA (msDNA-Ec107). Here, we show that this retron occurs in strains from different branches, A, B1, and D of a well-defined phylogenetic tree of a collection of wild E. coli. Sequence comparisons of the retrons from these three branches were carried out. Sequence homology was well conserved among the strains within the same branch and the retron sequence from branch A was exactly the same with that from branch D, while there were 18 base substitutions between the retrons from branch B1 and A or D, resulting in seven amino acid substitutions in reverse transcriptase. No substitutions were found in the msDNA- and msdRNA-coding regions, and there was no difference in the ability of msDNA production between them. These results suggest that the retron has probably been integrated into at least one of the three branches at an early stage of evolution and subsequently transferred to the other two branches, and also that the msDNA-producing system has been conserved during evolution with some mutations in the retron.

Base Sequence↗

PubMed1992

Unusual huge intramuscular granuloma with calcium phosphate crystal deposition in the buttock.

An unusual case of a huge granuloma featuring marked calcium phosphate crystal deposition in muscle is presented. A 58-year-old male demonstrated a well-circumscribed, large, elastic firm mass which had slowly grown over 8 years in the left buttock. Clinical examinations including X-ray, ultrasonography and computed tomography all suggested a neoplastic growth. Surgical excision revealed three inter-connected irregular-shaped masses, measuring up to 11 x 10 x 6 cm in size. The histological appearance was of granulomas composed of numerous small crystals surrounded by reactive mononuclear cells embedded in fibrous tissue containing many foreign body type giant cells. Chemical analysis demonstrated the crystals to be made up of calcium phosphate.

Buttocks↗

PubMed1992

Prodrugs of 2',3'-dideoxyinosine (DDI): improved oral bioavailability via hydrophobic esters.

Five ester prodrugs of 2'3'-dideoxyinosine (DDI) were synthesized for the purpose of improving oral bioavailability. The prodrugs, acetate (C2-DDI), octanoate (C8-DDI), stearate (C18-DDI), benzoate (Bz-DDI), and hemisuccinate (Suc-DDI) were proved to quantitatively regenerate their parent drug by enzymatic hydrolysis. Though the chemical stability of the prodrugs under acidic conditions was not improved, their solubility in water was significantly decreased by esterification, except for Suc-DDI. Bioavailability was evaluated by oral administration to rats. Two hydrophobic prodrugs (C8-DDI and Bz-DDI) showed higher absolute bioavailability (23.5% and 31.0%, respectively) than did DDI (15.2%), though that of C2-DDI (11.5%) and Suc-DDI (4.5%) was poor.

Administration, Oral↗

PubMed1992

Purification and some properties of a Haim-sensitive alpha-amylase from newly isolated Bacillus sp. No. 195.

Newly isolated Bacillus sp. No. 195 produced an extracellular alpha-amylase sensitive to Haim which was found to inhibit specifically animal alpha-amylases. The enzyme was purified easily by two steps of starch adsorption and gel filtration using Sephacryl S-200. The purified enzyme, which showed a single band on native-PAGE or SDS-PAGE, had a molecular weight of 60,000 as judged on SDS-PAGE. The optimum pH value for activity and the isoelectric point were around 7.0 and 4.5, respectively. The sensitivity of the amylase to Haim was similar to that of animal amylase rather than bacterial amylase. It was suggested that a Haim-amylase complex might be formed at the molar ratio of 1:1. The amino acid sequence F-S-W similar to the triplet F-E-W highly conserved among alpha-amylases sensitive to proteinaceous inhibitors, such as Hoe 467-A or Haim, was found in the amino-terminal part of the No. 195 amylase.

Amino Acid Sequence↗

PubMed1992

Expression of Mn-superoxide dismutase in carcinogenesis.

Human liver manganese superoxide dismutase (Mn-SOD) was highly purified by a simple procedure and crystallized. A monoclonal antibody against Mn-SOD, whose antigen-binding epitope is a C-terminus peptide was developed. Using this antibody, an enzyme-linked immunosorbent assay (ELISA) was developed. We found that Mn-SOD is highly expressed in human ovarian cancer and the serum level of the enzyme is a useful marker for the diagnosis and monitoring of the epithelial type of ovarian cancer. Tumor necrosis factor-alpha (TNF), lipopolysaccharide, IL-1 and phorbol ester induced the m-RNA of Mn-SOD as well as protein levels in TNF-resistant cells. No such induction was observed in Cu, Zn-SOD. Studies on the induction mechanisms indicated that at least two separate signal-transducing pathways are involved in expression of the Mn-SOD gene. One is triggered by protein kinase C activation itself in the absence of new protein synthesis. The other can be activated by stimulations with various cytokines in which a protein factor that can be induced by phorbol ester treatments is involved.

Biomarkers, Tumor↗

PubMed1992

Fibronectin degradation by human gastric carcinoma cell lines and its associated proteases in relation to stromal invasion in nude mice.

The invasiveness of human gastric carcinoma cell lines (MKN45 and MKN28) in the subcutaneous tissue of nude mice and the degrading capacities of extracellular matrix (ECM) were studied. MKN45 cells were more invasive than were the MKN28 cells. Immunostaining revealed dense lamellar accumulation of fibronectin (FN) around the tumors. Along the front of the invasive MKN45 growth, however, the FN fibers were discontinuous and/or had completely vanished; the MKN28 tumor showed no FN fiber disconnection. ECM components other than FN never displayed such peritumoral massive accumulation. Cocultivation of human fibroblasts with MKN45 cells, more evidently than with MKN28 cells, revealed degradation of FN produced by fibroblasts in contact with each tumor. Both cell lines produced several FN-degrading enzymes in serum-free cultures. Proteases from the MKN45 medium were more active than were those of MKN28 in urokinase-type plasminogen activator (uPA) and metal-dependent serine proteinase-like proteases of 75 and 68 kDa in molecular weight (MW). Type I collagen-degrading 48-kDa protease was also detected from MKN45 medium but not from the MKN28 medium. MKN28 cells secreted other kinds of FN-degrading enzymes, estimated at approximate MWs of 29 and 100-150 kDa. We found no distinct differences in capacity to produce ECM components or ability to adhere to purified ECM components between these two cell lines. From these results we conclude that the stromal invasion of these cells into the subcutaneous tissue of nude mice is profoundly related to their FN-degrading capability. This capability may be catalyzed by uPA and/or metal-dependent serine proteinase-like proteases of 75 and 68 kDa.

Adenocarcinoma↗

PubMed1992

[Comparison of treadmill exercise, handgrip, and cold-pressor tests: with particular reference to the effects on hemodynamics, respiratory gas exchange, and sympathetic nervous activity].

The treadmill test (TM), handgrip test (HG) and cold-pressor test (CP) are now frequently used clinically for multiple purposes. However, gas exchange analysis has not been a common procedure during HG. In particular, during CP, it has not been previously reported. Relationships between these 3 tests and blood pressure, heart rate (HR), respiratory gas exchange and the sympathetic nervous activity of normal subjects have not been reported, either. This study was undertaken to clarify these points. Symptom-limited TM was performed in 11 normal male subjects with a mean age of 45 +/- 8 yrs according to the Bruce protocol, with the HG using the weight-sustaining method (equal weight of 50% maximal voluntary contraction) for 3 min, and CP for 2 min. Systolic and diastolic blood pressures (Ps, Pd) were recorded; HR was measured every 30 sec, and gas exchange variables, such as oxygen uptake (VO2) and carbon dioxide production, were documented every 10 sec using an aereomonitor AE-280 (Minato Medical Science Co). In 10 of 11 subjects, concentrations of plasma noradrenaline (PNA) and plasma adrenaline (PAD) were measured at rest and at the times of peak values of the 3 tests. The peak values of Ps and HR were much higher during TM than during HG and CP (p < 0.01), while the peak values of Pd during HG and CP were higher than during TM (p < 0.01). The VO2 increased significantly for all of the 3 tests (TM: +781%, HG: +65%, CP: +20%), with the increment being the greatest during TM. Both PNA and PAD increased significantly for the 3 tests, with the increments of PNA and PAD being the greatest during TM. The percent change in PAD was more prominent during HG and CP than during TM. This tendency was not as clear for PNA as for PAD. There was no correlation of delta Ps and delta Pd between the 3 tests, but values of delta HR correlated partially. No significant correlations of peak VO2 were observed between the 3 tests. The peak PNA correlated between HG and CP (r = 0.77, p < 0.01), and the peak PAD correlated between TM and CP (r = 0.67, p < 0.05). In summary, numerous differences in hemodynamic and respiratory responses and in sympathetic nervous activation were observed in the 3 tests. When the 3 tests are undertaken, careful attention should be paid for their characteristics, discrepancies and limitations.

Adult↗

PubMed1992

Increased plasma decay-accelerating factor levels in paroxysmal nocturnal hemoglobinuria.

Decay-accelerating factor (DAF) is a complement regulatory membrane protein that is often absent from the cell surface of blood cells in paroxysmal nocturnal hemoglobinuria (PNH). DAF has also recently been found in the body fluids of healthy individuals. However, its precise structure and biological significance are not yet clear. To clarify the clinical and pathological implications of free DAF, we measured plasma DAF levels in PNH patients, using a newly developed quantitative enzyme-linked immunosorbent assay (ELISA), with a measurable range between 0.2-12 ng, for soluble DAF. ELISA assays revealed significantly increased plasma DAF levels in PNH patients (258 +/- 150 ng/ml, mean +/- S.D., n = 9) as compared with healthy controls (80 +/- 41 ng/ml, n = 17) (p less than 0.01). Taken together with the finding that DAF is synthesized in and released extracellularly from affected PNH cells, plasma DAF levels would be useful for clinical diagnosis and for the quantitative evaluation of the clonal expansion of affected cells in PNH.

Adult↗

PubMed1992

Altered expression of protein kinase C in adult T-cell leukemia cells.

Protein kinase C (PKC) has been shown to be involved in the mitogenic response and in oncogenic cell transformation in many experimental models. We analyzed the expression of PKC in both highly purified leukemic T cells freshly isolated from adult T-cell leukemia (ATL) patients and control T lymphocytes obtained from healthy volunteers. PKC activity was decreased in the ATL cells as compared with the control T cells. Cytosolic PKC activity in the ATL cells was remarkably decreased, whereas particulate membrane PKC activity was similar to the control level. The percentage of PKC activity in the particulate fraction was 34% in the ATL cells and 19% in the control cells. Regarding the altered subcellular localization of PKC activity, phorbol ester-induced translocation of cytosolic PKC was inhibited in some ATL cases. Similarly to the decrease in PKC activity, there was a decrease in the expression of the major PKC isozymes II(beta) and III(alpha) in ATL cells. These results suggest impaired regulation of PKC expression in ATL as well as in many experimental cancers.

Adult↗