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H Sawada

Publications and source records attributed to H Sawada.

At least 253 records · Page 14Linked to original sources
PubMed1993

Purification and properties of N-acetylglucosaminidase from eggs of the ascidian, Halocynthia roretzi.

In several ascidians, beta-D-N-acetylglucosaminidase (GlcNAcase) released from eggs following fertilization is proposed to play a key role in polyspermy block through its binding to the sperm receptor on the vitelline coat [C. C. Lambert (1989) Development 105, 415-420]. In the ascidian Halocynthia roretzi, GlcNAc-specific lectins inhibited the fertilization most strongly among various lectins. Furthermore, GlcNAcase activity was released from the eggs in response to the egg activation. The GlcNAcase was purified from the eggs to apparent homogeneity by chromatographies on DEAE-Toyopearl, SP-Toyopearl, Toyopearl HW-65, and Mono S. The purified enzyme gave a single band on isoelectric focusing with an isoelectric point of 7.0. It gave two bands on SDS/PAGE: the molecular masses of the bands were estimated to be 65 kDa/66 kDa, and 84 kDa/85 kDa under reducing/non-reducing conditions, respectively. The two bands were found to converge to a single band of 56 kDa after deglycosylation, which suggests microheterogeneity in the sugar moiety. The enzyme showed an oligomeric structure with an apparent molecular mass of 520 kDa, estimated by gel filtration. The optimum pH of the activity was around 4.5. The enzyme hydrolyzed both 4-methylumbelliferyl-GlcNAc and 4-methylumbelliferyl-GalNAc, suggesting that it should be characterized as a beta-D-N-acetylhexosaminidase, with Km values of 1.2 mM and 0.52 mM, respectively. The purified enzyme was found to be capable of binding to the vitelline coat in a GlcNAc-specific manner. Immunoblot analysis using antibody raised against the purified GlcNAcase revealed that the enzyme itself is released from the eggs upon fertilization. Thus, the GlcNAcase purified in this study is released from eggs following fertilization and bound to the vitelline coat in order to function in the polyspermy blocking mechanism.

Acetylglucosaminidase↗
PubMed1993

Effects of protease inhibitors on binding of sperm to the vitelline coat of ascidian eggs: implications for participation of a proteasome (multicatalytic proteinase complex).

Among various protease inhibitors, chymostatin (an inhibitor of sperm chymotrypsin-like protease) strongly inhibited the binding of sperm to the vitelline coat of glycerinated eggs of the ascidian Halocynthia roretzi, whereas leupeptin (an inhibitor for sperm acrosin), antipain, and soybean trypsin inhibitor had no significant inhibitory effects. Dansyl-Val-Pro-argininal (an inhibitor of the sperm trypsin-like protease, spermosin) had an inhibitory effect on the binding of sperm that was much smaller than its effects on fertilization. Since the sperm chymotrypsin-like protease that is involved in ascidian fertilization has been identified as a proteasome (multicatalytic proteinase complex), we tested the effects of several peptidyl argininals, inhibitors of the activities of proteasomes, on this binding process. The ranking of the inhibitory effects of these compounds on the binding of sperm was the same as that of their effects on the chymotrypsin-like activity of the proteasome, reported previously. The potent inhibitors of binding used in these studies had no or minimal effects on sperm motility. These results suggest that a sperm chymotrypsin-like protease (most probably the chymotrypsin-like protease in the proteasome) plays a key role in binding of sperm to the vitelline coat of the ascidian egg.

Amino Acid Sequence↗
PubMed1993

Chemoprevention of oral carcinogenesis by DL-alpha-difluoromethylornithine, an ornithine decarboxylase inhibitor: dose-dependent reduction in 4-nitroquinoline 1-oxide-induced tongue neoplasms in rats.

The modifying effect of three doses of DL-alpha-difluoromethylornithine (DFMO) given p.o. during the post-initiation phase of tongue carcinogenesis initiated by 4-nitroquinoline 1-oxide (4-NQO) was studied in male ACI/N rats. Animals were given 4-NQO at 20 ppm for 8 weeks in the drinking water to induce tongue neoplasms. One week after the stop of 4-NQO treatment, rats were transferred to the drinking water containing DFMO at concentrations of 100, 1000, and 2000 ppm for 25 weeks. The other groups consisted of rats given 2000 ppm DFMO alone or untreated rats. Thirty-four weeks after the start of the experiment, all animals were necropsied, and the incidences of neoplasms and preneoplastic lesions in the tongue, polyamine levels in the bloods and tongue tissues, and cell proliferation estimated by the number and area of silver-stained nucleolar organizer regions in the tongue epithelium were compared among the groups. Feeding of DFMO at all doses significantly inhibited the incidence of tongue neoplasms compared to the group given 4-NQO alone. DFMO at levels of 1000 and 2000 ppm significantly reduced the incidence of preneoplastic lesions of the tongue. Results analyzed by the linear regression method suggested a dose-dependent inhibition in the incidences of neoplastic and preneoplastic lesions of the tongue with increasing levels of DFMO. Increased levels in polyamines in the blood and tongue tissue were significantly suppressed by the treatment of DFMO. Also, silver-stained nucleolar organizer region indices were significantly reduced by the DFMO exposure. These results indicate that increasing levels of DFMO in the drinking water inhibited 4-NQO-induced tongue carcinogenesis in a dose-dependent manner and such inhibition was related to reduction in the polyamine levels of blood and tissue and decrease in the cell proliferation.

4-Nitroquinoline-1-oxide↗
PubMed1993

Monkey 3-deoxyglucosone reductase: tissue distribution and purification of three multiple forms of the kidney enzyme that are identical with dihydrodiol dehydrogenase, aldehyde reductase, and aldose reductase.

3-Deoxyglucosone (3DG) is a reactive intermediate in the glucose-mediated cross-linking of proteins. An enzyme catalyzing the reduction of 3DG is thought to prevent the damage to protein by the formation of 3DG. The NADPH-dependent enzyme activity was detected in the extracts of various monkey tissues, among which kidney exhibited the highest specific activity. One dimeric enzyme with subunit M(r) of 39,000 and two monomeric enzymes with M(r) of 38,000 and 34,000 were purified from monkey kidney. The dimeric enzyme exhibited high dihydrodiol dehydrogenase activity and was immunochemically identical to dimeric dihydrodiol dehydrogenase of monkey kidney. The two monomeric enzymes exhibited aldehyde reductase activity, but were clearly distinct from each other in substrate specificity, inhibitor sensitivity, and effect of sulfate ions. One enzyme was immunologically cross-reacted with human liver aldehyde reductase, whereas sequence data of digested peptides from the other enzyme revealed > 97% identity with human placental aldose reductase. Comparison of kinetic constants among the monkey kidney enzymes and aldoketo reductases from several mammalian tissues indicated that dimeric dihydrodiol dehydrogenase and aldose reductase exhibited higher catalytic efficiency for 3DG than did aldehyde reductase, carbonyl reductase, and monomeric dihydrodiol dehydrogenase.

Alcohol Oxidoreductases↗
PubMed1993

High-molecular-weight protease complexes (proteasomes) of sperm of the ascidian, Halocynthia roretzi: isolation, characterization, and physiological roles in fertilization.

It has been proposed that a chymotrypsin-like enzyme plays a key role in sperm penetration through the vitelline coat of eggs of the ascidian, Halocynthia roretzi. In this report, two kinds of chymotrypsin-like enzymes were isolated from spermatozoa of H. roretzi. Both enzymes were characterized as high-molecular-weight protease complexes that comprised several different subunits and that showed several different protease activities. Both showed immunoreactivity with anti-proteasome antibody. One showed properties characteristic of the 20 S proteasome and its molecular mass was 630 kDa, whereas the other protease complex of 930 kDa showed inhibitor susceptibility different from that of the 20 S proteasome. Upon the sperm reaction which is induced by treatment with high pH, the proteasomes were found to be released from sperm and they had the activity to digest the vitelline coats. These results suggest that the proteasomes are exposed extracellularly when sperm contact with the egg coat and may function as lysins in the fertilization process.

Amino Acid Sequence↗
PubMed1993

Alpha-fetoprotein-producing esophageal adenocarcinoma: report of a case.

This paper describes a rare case of adenocarcinoma located in the middle portion of the esophagus with liver metastasis. An 80-year-old man was admitted to our hospital with dysphagia and vomiting, following which an upper gastrointestinal series and esophagoscopy located an elevated-type carcinoma in the middle thoracic esophagus. Computed tomography revealed an esophageal tumor invading the left atrium and aorta, and multiple intrathoracic lymph node swellings, and an ultrasonograph of the liver showed multiple liver metastases. The serum carcinoembryonic antigen, carbohydrate antigen 19-9, and squamous cell carcinoma-related antigen levels were normal, but the serum alpha-fetoprotein (AFP) level was 351.5 ng/ml. The patient died 124 days after undergoing an esophageal bypass operation. On post-mortem histological examination, the original esophageal tumor was diagnosed as a poorly differentiated adenocarcinoma without a squamous component and immunohistochemical staining for AFP showed positive granules in the cytoplasm. All the metastatic nodules, including the lymph nodes, liver, spleen, and lungs, showed the same histological type and AFP-staining pattern as the original esophageal tumor. To our knowledge, this is the first case of AFP-producing esophageal carcinoma to be reported in Japan.

Adenocarcinoma↗
PubMed1993

Adult neuroblastoma in pregnancy: report of a case.

We report herein an extremely rare case of retroperitoneal neuroblastoma occurring in a mother during her third trimester of pregnancy. A live male infant was delivered by cesarean section at 36 weeks gestation and 23 days later, the mother's tumor was curatively resected. Six months have elapsed since her operation and there has been no evidence of tumor recurrence. Adult neuroblastoma is an uncommon malignancy and, to our knowledge, there has been no case of this tumor occurring in pregnancy ever described in the English literature. The diagnosis, treatment, and follow-up of this neoplasm and its association with pregnancy are discussed in this report.

Adult↗
PubMed1993

Living related liver transplantation across ABO blood groups with FK506 and OKT3.

In living related liver transplantation (LRLT), the use of graft livers across ABO blood groups is unavoidable since the organ donor is usually one of the recipient's parents. This report presents our initial experiences with LRLT, focusing on ABO-incompatible cases. From June 1990 to May 1992, we successfully performed a series of 34 LRLT on children (15 males and 19 females) ranging in age from 7 months to 15 years. Overall recipient survival rates were 90% (25/28) in elective LRLT and 50% (3/6) in emergency LRLT. These cases were classified into three groups: ABO blood group-identical (n = 21), compatible (n = 10), and incompatible (n = 3). The immunosuppressive regimen consisted of FK506 and low-dose steroids in the first two groups. In the incompatible cases, exchange transfusion was performed to decrease anti-A and/or -B antibody titers before LRLT, and prophylactic OKT3 was added to FK506 and steroids after LRLT. No significant difference in recipient and graft survival was observed among the groups. In the identical group, no rejection episodes have been observed thus far. Rejection occurred in two out of the ten compatible cases. Among the incompatible cases, one recipient had mild rejection and was treated. The remaining two recipients have had no rejection episodes thus far. Although all three recipients had cytomegalovirus (CMV) infection, they were successfully treated with ganciclovir, and no lethal infection has developed in any of these cases. The present results suggest that graft livers from living related donors across ABO blood groups can function well with FK506, low-dose steroids, and prophylactic OKT3 without causing lethal complications.

ABO Blood-Group System↗
PubMed1993

Saponins from leaves of Acanthopanax sieboldianus.

Two new triterpenoid saponins named sieboldianoside A and B were isolated from the leaves of Acanthopanax sieboldianus together with five known triterpenoid saponins, kalopanax-saponins A and B, saponin A, CP3, sapindoside B, and a known flavonol glycoside, kaempferol 3-O-rutinoside. On the basis of chemical and spectral evidence, the structures of the new saponins (sieboldianoside A and B) were concluded to be alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)- beta-D-glucopyranosyl esters of hederagenin and oleanolic acid 3-O-beta-D- xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopy ranosides, respectively.

Carbohydrate Sequence↗
PubMed1993

Surgical techniques and innovations in living related liver transplantation.

The authors successfully performed a series of 33 living related liver transplantations (LRLT) on children (15 males and 18 females, ranging from 7 months to 15 years of age) from June 1990 to May 1992, with the informed consent of their parents and the approval of the Ethics Committee of Kyoto University. Before operation, six of the children required intensive care, another 14 were hospitalized, and 13 were homebound. Donors (12 paternal and 21 maternal) were selected solely from the parents of the recipients on the basis of ABO blood group and graft/recipient size matching determined by computed tomography scanning. Procurement of graft was performed using ultrasonic aspirator and bipolar electrocautery without blood vessel clamping and without graft manipulation. All donors subsequently had normal liver function and returned to normal life. The left lateral segment (16 cases), left lobe (16 cases), or right lobe (one case) were used as grafts. The partial liver graft was transplanted into the recipient who underwent total hepatectomy with preservation of the inferior vena cava using a vascular side clamp. Twenty-seven of 33 recipients are alive and well with the original graft and have normal liver function. The patient survival rate was 89% (24/27) in elective cases and 50% (3/6) in emergent cases. The other six recipients had functioning grafts but died of extrahepatic complications. Complications of the graft were minimal in all cases. Hepatic vein stenosis, which occurred three times in two cases, was successfully treated by balloon dilatation. In cases with sclerotic portal vein, the authors anastomosed the portal vein of the graft to the confluence of the splenic vein and the superior mesenteric vein without a vascular graft, after experiencing a case of vascular graft thrombosis. After hepatic artery thrombosis occurred in one of the initial seven recipients whose arterial anastomosis was done with surgical loupe, microsurgery was introduced for hepatic artery reconstruction. There has been no occurrence of thrombosis since then. The current results with LRLT suggested that the meticulous management of surgical factors at each stage of the LRLT procedure is crucial for successful outcome. Living related liver transplantation is a promising option for resolving the graft shortage in pediatric liver transplantation and may be regarded as an independent modality to supplement cadaver donation.

Adolescent↗
PubMed1993

Proposal for rejection of Agrobacterium tumefaciens and revised descriptions for the genus Agrobacterium and for Agrobacterium radiobacter and Agrobacterium rhizogenes.

The 16S rRNA sequences of seven representative Agrobacterium strains, eight representative Rhizobium strains, and the type strains of Azorhizobium caulinodans and Bradyrhizobium japonicum were determined. These strains included the type strains of Agrobacterium tumefaciens, Agrobacterium rhizogenes, Agrobacterium radiobacter, Agrobacterium vitis, Agrobacterium rubi, Rhizobium fredii, Rhizobium galegae, Rhizobium huakuii, Rhizobium leguminosarum, Rhizobium loti, Rhizobium meliloti, and Rhizobium tropici. A phylogenetic analysis showed that the 15 strains of Agrobacterium and Rhizobium species formed a compact phylogenetic cluster clearly separated from the other members of the alpha subclass of the Proteobacteria. However, Agrobacterium species and Rhizobium species are phylogenetically entwined with one another, and the two genera cannot be separated. In the Agrobacterium species, the strains of biovar 1, biovar 2, Agrobacterium rubi, and Agrobacterium vitis were clearly separated. The two biovars exhibited homogeneity in their phenotypic, chemotaxonomic, and phylogenetic characteristics, and two species should be established for the two biovars. We considered the nomenclature of the two biovars, and revised descriptions of Agrobacterium radiobacter (for the biovar 1 strains) and Agrobacterium rhizogenes (for the biovar 2 strains) are proposed. The name Agrobacterium tumefaciens is rejected because the type strain of this species was assigned to Agrobacterium radiobacter, and consequently the description of the genus Agrobacterium is revised.

Agrobacterium tumefaciens↗
PubMed1993

[Clinical study of patients with deep-seated fungal infection associated with hematological diseases].

An assessment has been made regarding usefulness of measuring beta-D-glucan (beta-glucan) as fungal serodiagnosis in 50 cases of fungal infection with hematological diseases. Further, an assessment has been made regarding relation between hematological findings and therapeutic effect by administering miconazole, an antifungal agent (MCZ: Florid, clinically to the subjects. Positivity of beta-glucan (beta-glucan > or = 10 pg/ml) was observed in 54.5% (24/44), and the effective rate of MCZ in the positive cases was 75.0% (18/24). In the cases in whom fungus was detected, beta-glucan-positive rate was 50.0% (8/16), and MCZ-effective rate in beta-glucan-positive cases was 62.5% (5/8). The total effective rate of MCZ was 80% (40/50). Side effects were observed in 3 cases, but continual administration of MCZ was possible in all of the 3 cases. By the assessment regarding the relation between hematological findings and therapeutic effect of MCZ, it was found that the effective rates in the cases who underwent a transition with neutrophil and lymphocyte counts less than 500/microliters during the period of MCZ administration were 64.7% (11/17) and 50% (5/10), respectively, and large effects were observed in the cases who underwent a transition with the neutrophil and lymphocyte counts more than 500/microliters was 86.7% (19/22) and 91.7% (22/24), respectively. These results suggested that lymphocytes rather than neutrophils had an important role in the morbidity of fungal infection. It was noteworthy that MCZ was effective for the treatment of deep seated mycosis and significant effective rate was obtained in the group of patients who had neutrophils and lymphocytes less than 500/microliters.

Adolescent↗
PubMed1993

Physarum vitronectin-like protein has extensive homology to dihydrolipoamide acetyltransferase.

Physarum vitronectin-like protein with a molecular mass of 70 kDa cross-reacts with anti-bovine vitronectin and promotes cell-spreading (Miyazaki, K. et al. 1992. Exp. Cell Res., 199: 106-110.). The amino-terminal sequence of Physarum vitronectin-like protein is, however, distinct from those of animal vitronectins but shows significant sequence homology with dihydrolipoamide acetyltransferase, a component of pyruvate dehydrogenase complex. We have investigated the structural relationships between Physarum vitronectin-like protein and dihydrolipoamide acetyltransferase by using both antibody and protein-chemical methods. The vitronectin-like protein reacted with both anti-bovine vitronectin IgG and anti-rat pyruvate dehydrogenase complex IgG, indicating that it shares common antigenic determinant(s) with rat pyruvate dehydrogenase complex. Furthermore, sequencing studies of peptides obtained by lysylendopeptidase digestion indicated that internal sequences of Physarum vitronectin-like protein show significant homology with dihydrolipoamide acetyltransferase, but do not show any homology with the primary structures of authentic vitronectins. Immunocytochemistry revealed that the protein is widely localized in cytoplasm and nuclei of Physarum polycephalum, but is not present in the central area of vacuoles. Our results indicate that Physarum vitronectin-like protein is a molecule structurally and immunologically related to dihydrolipoamide acetyltransferase but functionally similar to animal vitronectin, although its localization is unique.

Acetyltransferases↗
PubMed1993

Okadaic acid biologically mimics the role of calcium/phospholipid dependent kinase inhibitors in the process of HL-60 cell differentiation.

Okadaic acid, a newly recognized protein phosphatase inhibitor and a non-TPA type tumor promoter, enhanced 1 alpha 25(OH)2D3(D3)-induced HL-60 cell differentiation into monocyte/macrophage lineage but did not affect dibutyryl cyclic AMP (dbcAMP)-induced differentiation into granulocytic lineage. Okadaic acid alone did not induce any differentiation. The process of D3-induced HL-60 cell differentiation on cultivation in magnesium deficient medium can be divided into two steps namely commitment and phenotypic expression as we have previously reported (J Cell Physiol 1987;131:50; Cell Growth Diff 1991;2:415), and the effect of okadaic acid on each step was studied. The results obtained indicated that okadaic acid inhibited commitment and enhanced phenotypic expression. We have previously shown that PKC has a dual action in the process of differentiation, i.e. as a positive regulatory signal in commitment and as a negative one in phenotypic expression. Thus, although okadaic acid has been reported to enhance the phosphorylation of various proteins that are also phosphorylated by PKC, we found that it mimics the role of PKC inhibitors such as H7 and staurosporine in D3-induced HL-60 cell differentiation.

Calcitriol↗
PubMed1993

[Utility of measurement of tumor markers for preoperative staging of gastric cancer].

In 120 operated cases of gastric cancer, nine tumor makers (serum carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), tissue polypeptide antigen (TPA), serum beta 2-microglobulin (s-BMG), urine beta 2-microglobulin (mu-BMG), serum immunosuppressive acidic protein (IAP) and sialic acid (SA)) were determined before operation, to explore distribution patterns, positive rates, and relationships among these markers. And, we explored tumor markers which would be useful in preoperative assessment of the cancer stage and feasibility of radical treatment. The following results were obtained. 1. The distribution of all tumor markers was close to normal logarithmic distribution. 2. The positive rate was high in the order of IAP > TPA > CEA > CA19-9 >s-BMG > SA > u-BMG > CA125 > AFP. 3. Strong correlations were observed between IAP and SA, between CA125 and TPA. 4. The optimum combination of markers for diagnosis of the cancer stage was IAP + CA19-9 + CA125 and the optimum combination for assessment of the feasibility of radical treatment was IAP + CA125 + TPA.

Adult↗