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Biomedical subjects

K Sugiyama

Publications and source records attributed to K Sugiyama.

At least 91 records · Page 5Linked to original sources
PubMed2000

Tissue-specific expression of c-series gangliosides in the extraneural system.

c-Series gangliosides in extraneural tissues from young and adult rats were examined using thin-layer chromatographic (TLC) immunostaining with a specific monoclonal antibody A2B5. The composition of c-series gangliosides significantly differed among tissues. In adult rats, while liver tissue contained GT1c, GQ1c, and GP1c, renal tissue had GT3 as the major c-series ganglioside with GT2 in a lesser amount. Pancreatic tissue expressed c-series gangliosides that consisted of GT3, GT2, GQ1c, and GP1c. In other tissues including adrenal, thyroid, and eye lens, GT3 constituted the main c-series ganglioside species. While total ganglioside contents of extraneural tissues were much lower than that of brain tissue, the proportions of c-series gangliosides to total gangliosides were higher in many extraneural tissues. Interestingly, eye lens had the highest GT3 content among rat tissues examined. The compositions and concentrations of c-series gangliosides in liver and kidney significantly differed between 5-day-old and 7-week-old rats, suggesting the development-dependent expression of c-series gangliosides in these tissues. These results suggest that the expression of c-series gangliosides in extraneural tissues is regulated in a tissue-specific manner.

Age Factors↗
PubMed2000

UCN-01 selectively enhances mitomycin C cytotoxicity in p53 defective cells which is mediated through S and/or G(2) checkpoint abrogation.

We have previously reported that UCN-01 (7-hydroxystaurosporine), a protein kinase inhibitor that is under clinical trials as an anti-cancer agent in the USA and Japan, enhanced the anti-tumor activity of mitomycin C (MMC) in vitro and in vivo. Subsequent studies from other laboratories revealed that UCN-01 could selectively enhance cytotoxicity of DNA damaging agents in p53 defective cells and that this was mediated by abrogation of S and /or G(2) arrest by UCN-01. In this study, we report that UCN-01 selectively enhances the cytotoxicity of MMC in human p53 mutant cell lines. In contrast, UCN-01 showed little, if any, effect on MMC cytotoxicity in human p53 wild-type cell lines. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-nick end-labeling (TUNEL) assay revealed that the combination of MMC with UCN-01 increased DNA breaks consistent with apoptosis in p53 defective A431 epidermoid carcinoma cells. In p53 wild-type MCF-7 breast carcinoma cells, the cyclin-dependent kinase inhibitor protein p21/WAF1 was markedly induced after the treatment with MMC alone, although this response was significantly delayed from the time of MMC treatment. Detailed cell-cycle studies revealed that UCN-01 abrogated S and G(2) phase accumulation induced by MMC in p53 defective cells and to a lesser extent in p53 wild-type cell lines. The abrogation of arrest in p53 wild-type cells was observed prior to significant induction of the p53 response. Since MMC was less effective against p53 defective cell lines than against p53 wild-type cell lines and UCN-01 selectively enhanced MMC cytotoxicity in p53 defective cell lines, UCN-01 may provide a new modality of MMC-based cancer chemotherapy, particularly in p53 defective cancer patients.

Alkaloids↗
PubMed2000

Isolation of a non-covalent aldose reductase-nucleotide-inhibitor complex.

A method for the isolation of an intact, non-covalent complex formed by the interaction of aldose reductase, NADP(H) nucleotide, and inhibitor has been developed to aid in the discovery and development of novel aldose reductase inhibitors. In the complexes isolated, both the carboxylic acid-containing inhibitor tolrestat and the spirohydantoin-containing inhibitor AL1576 (2,7-difluorospirofluorene-9,5'-imidazolidine-2',4'-dione) tightly bound in a 1:1 ratio to aldose reductase complexed with either NADPH or NADP+. Inhibitor binding to either the enzyme-NADP+ or enzyme-NADPH complex appeared to be equal and pH-dependent, with maximum binding observed at a pH range of 7 to 8.5 where the inhibitors are ionized. These results indicated that the charge state of the cofactor (NADPH vs NADP+) is not critical for inhibitor binding to aldose reductase. Molecular modeling studies suggested that His110 plays a crucial role in directing charged inhibitors containing either a carboxylate or an ionizable hydantoin group to the active site of aldose reductase by providing charge interaction.

Aldehyde Reductase↗
PubMed2000

The effect of retreatment with interferon-alpha on the incidence of hepatocellular carcinoma in patients with chronic hepatitis C.

BACKGROUND: Interferon (IFN) has been reported to have beneficial long term effects that reduce the occurrence of hepatocellular carcinoma (HCC), even in patients who do not have complete responses to IFN. The authors evaluated the effect of retreatment with IFN-alpha on the long term prognoses of those with incomplete responses to their initial IFN-alpha treatment. METHODS: Among 271 patients with incomplete responses to initial IFN-alpha treatment who had received sufficient dose and duration (a total dose of more than 350 megaunits administered over a period longer than 12 weeks) between October 1989 and September 1997, 63 patients received retreatment and 208 did not. The authors retrospectively compared the incidence of HCC between patients who received retreatment and those who did not. RESULTS: There were no significant differences in the clinical characteristics between these two groups. The cumulative incidence of HCC was significantly lower among the patients who had retreatment, and retreatment with IFN-alpha was the only factor that correlated with the lower incidence of HCC in multivariate analysis. The results were similar when the 12 patients with complete responses to retreatment were excluded from the analysis. CONCLUSIONS: Retreatment with IFN-alpha appeared to have the additional effect of suppressing the development of HCC in patients who had incomplete responses to the initial treatment, even when the hepatitis C virus was not cleared (i.e., a complete response was not achieved) with retreatment. Further prospective study is required.

Adolescent↗
PubMed2000

Prevalence of TTV DNA among children with a history of transfusion or liver disease.

The prevalence rates of serum TT virus (TTV) DNA among children with or without a history of transfusion or liver disease were studied by polymerase chain reaction (PCR) using either the Okamoto primer set or the Takahashi primer set developed more recently. Using Okamoto and Takahashi primer sets, the prevalence rates were 31.6% (12/38) and 78.9% (30/38), respectively, for children with a history of blood transfusion (including malignant and non-malignant groups) and 6.7% (2/30) and 60% (18/30), respectively, for children without a history of blood transfusion. Among pregnant women, these rates were 12.9% (4/31) and 61.3% (19/31), respectively. On the other hand, the prevalence rates were 0% (0/16) and 50% (8/16), respectively, in hepatitis B patients, 21.4% (3/14) and 71.4% (10/14), respectively, for hepatitis C patients, and 20.0% (9/45) and 57.8% (26/45), respectively, for non-A to C hepatitis patients (including 27 acute hepatitis patients, 5 fulminant patients and 13 chronic hepatitis patients). In this study, the prevalence rates determined by the Takahashi primer set tended to be 2-9 times higher than those determined using the Okamoto primer set. These results suggest that TTV infection is widespread among Japanese children. Furthermore, blood transfusion does not appear to be the major route of infection. The similar prevalence rates between control children and children with various types of hepatitis using the Takahashi primer system suggest that TTV infection does not play a direct causative role in the development of liver disease in children.

Adult↗
PubMed2000

Identification of a larger than 3 Mb deletion including JAG1 in an Alagille syndrome patient with a translocation t(3;20)(q13.3;p12.2).

Alagille syndrome (AGS) is an autosomal dominant, developmental disorder affecting multiple organ systems including liver, heart, vertebrae, eye and face. Recurrent deletions of the 20p12 region led to the localization, and ultimately to the identification of mutations in the Jagged1 gene (JAG1) in AGS patients. A translocation t(3;20)(q13.3;p12.2) in an AGS patient was characterized using fluorescent in situ hybridization (FISH). The involvement of 3q and 20p in this translocation was demonstrated using probes for 3q and 20p. Three overlapping YAC clones, 940D11, 953A2, and 675G11 extending to nearly 4 Mb including the JAG1 were used as probes for FISH analysis to define the translocation breakpoint. The translocated chromosome was found to have a deletion of more than 3 Mb including the entire JAG1 gene. The observation of an accompanying large deletion, revealed by molecular characterization of the t(3;20) translocation, is similar to the only other translocation reported in an AGS patient; a t(2;20) translocation was also found to have a large deletion of the JAG1 region at 20p12.

Alagille Syndrome↗
PubMed2000

Cardiac metastatic liposarcoma.

Metastatic cardiac liposarcoma is extremely rare, with only 2 cases previously reported, to our knowledge; of those, only 5 involved surgical resection of right ventricular liposarcoma. The first such case in Japan involved a 61-year-old woman with metastatic liposarcoma of the right ventricle. Despite emergency resection, the patient died of severe congestive heart failure 6 days after operation. Her history included surgery for liposarcoma in the right knee 11 years previously, although it is very difficult to predict that metastasis would proceed thereafter to the cardiac cavity. This rare case suggests, however, that follow-up including examination for cardiac lesions is necessary long after resection of the primary lesion.

Female↗
PubMed2000

Enterobacter cowaniisp. nov., a new species of the family Enterobacteriaceae.

The name Enterobacter cowanii sp. nov. is proposed for a group of organisms referred to as NIH Group 42. Members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae. The DNA relatedness of nine strains of NIH Group 42 to the proposed type strain of this species averaged 85% at 70 degrees C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 38%. Because the DNA relatedness (5-38%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 42 were placed in the genus Enterobacter. The majority of strains of E. cowanii were isolated from clinical specimens. A culture of the type strain (888-76) has been deposited in the Japan Collection of Microorganisms as JCM 10956.

Bacterial Typing Techniques↗
PubMed2000

Disk hemorrhage is a significantly negative prognostic factor in normal-tension glaucoma.

PURPOSE: We investigated the relationship between disk hemorrhage in normal-tension glaucoma and the progression of visual field defects and, additionally, whether hemorrhage plays a role in the pathogenic process of the chronic disease. METHODS: We retrospectively reviewed the charts of 70 patients with normal-tension glaucoma (mean follow-up, 5.6 years) who were not medicated for glaucoma, and we applied a regression analysis of survival data based on the Cox proportional hazards model. Several clinical factors were investigated to find a possible association with the progression of glaucomatous visual field defined by two different definitions: one by mean deviation change and the other by glaucoma change probability analysis. RESULTS: Disk hemorrhage, corrected-pattern standard deviation, age, systolic blood pressure, and pulse rate had a significant influence on the visual field defect. The cumulative probability of progression of visual field loss was significantly greater for patients with disk hemorrhage than for patients without disk hemorrhage by either criterion for progression (P </=.0008, logrank test). All eyes that had at least two occurrences of disk hemorrhage showed progression, whereas only three of nine eyes showed progression in the nonrecurrent disk hemorrhage group by the glaucoma change probability analysis. The difference was statistically significant (P <.0001, Fisher's exact probability test). Furthermore, there was a significant relationship between the location of the disk hemorrhage and the area of the progression of visual field loss in 65.4% of progressive patients with disk hemorrhage. CONCLUSIONS: Several clinical factors other than intraocular pressure are significantly associated with the progression of visual field loss during the natural course of normal-tension glaucoma. Among these, disk hemorrhage is a significantly negative prognostic factor in patients with normal-tension glaucoma and may be a sign of progressive damage of the retinal nerve fiber layer, leading to functional deterioration of the visual field.

Adult↗
PubMed2000

Characterization of antiviral activity of lactoferrin against hepatitis C virus infection in human cultured cells.

We recently found that bovine lactoferrin (bLF), a milk glycoprotein belonging to the iron transporter family, prevented hepatitis C virus (HCV) infection in human hepatocyte PH5CH8 cells, that are susceptible to HCV infection, and demonstrated that the anti-HCV activity of bLF was due to the interaction of bLF and HCV. In this study we further characterized the anti-HCV activity of bLF and the mechanism by which bLF prevents HCV infection. We found that bLF inhibited viral entry to the cells by interacting directly with HCV immediately after mixing of bLF and HCV inoculum. The anti-HCV activity of bLF was lost by heating at 65 degrees C, and other milk proteins (mucin, beta-lactoglobulin and casein) did not prevent HCV infection, indicating that bLF prevented HCV infection in a rather specific manner. Furthermore, we found that bovine lactoferricin, a basic N-terminal loop of bLF that is an important region for antibacterial activity, did not exhibit any anti-HCV activity, suggesting that some other region is involved in anti-HCV activity. We confirmed that prevention of HCV infection by bLF was a general phenomenon, because bLF inhibited HCV infection with all five inocula examined, and bLF inhibited HCV infection in human MT-2C T-cells, that were susceptible to HCV infection. In addition, infection with hepatitis G virus, which is distantly related to HCV, was prevented also by bLF. In conclusion, lactoferrin is a natural glycoprotein which effectively protects against HCV infection in hepatocytes and lymphocytes by neutralizing the virus.

Animals↗
PubMed2000

A report of 14,195 applications of anesthetics to oral and maxillofacial surgery at one teaching dental hospital (1971-2000) centering around airway problems.

STUDY OBJECTIVES: To examine the validity of our methods of anesthesia, i.e., awake intubation and assisted manual ventilation, in coping with the anesthetic problems particular to oral and maxillofacial surgery (OMF surgery). DESIGN: Prospective study. SETTING: Operating room and ward of a dental teaching hospital. PATIENTS: 14,195 patients undergoing OMF surgery during the period from January 1971 to March 2000. MEASUREMENTS AND MAIN RESULTS: The kinds of anesthetic difficulties centering around airway problems and their frequency in OMF surgery were determined. In 2,401 patients (16.9%), awake intubation was employed because of definite or possible airway problems. No untoward effects due to awake intubation were noted. Volatile anesthetics were used with nitrous oxide (N2O) in 13,959 patients (98.3%), and their spontaneous respiration were assisted manually for the purpose of early detection of airway troubles such as accidental extubation, dislocation, kinking, and/or damage to the endotracheal tubes. Few accidents or complications were noted in relation to airway issues, and neither cardiac arrest nor death was experienced in these 14,195 patients. CONCLUSIONS: Based on a sufficient number of anesthetic applications, awake intubation and assisted manual ventilation were proved to be useful in coping with the anesthetic difficulties particular to OMF surgery.

Adolescent↗
PubMed2000

Membrane-type 1 matrix metalloproteinase enhances lymph node metastasis of gastric cancer.

The mechanisms of the lymph node metastasis remain unclear. We demonstrate the role of MT1-MMP on the lymph node metastasis using in vivo experimental model of lymph node metastasis by orthotopic implantation of MT1-MMP transfected gastric cancer cell line in the stomach of nude rats. TMK-1 cell line without expression of MT1-MMP was transfected with the pcDNA3 plasmid containing a 3.4-kb MT1-MMP cDNA fragment by calcium phosphate method, and the transfected cell line was designated as TMK-MT. Western blot and RT-PCR analyses showed the specific bands corresponding to MT1-MMP in the TMK-MT cells. By gelatin zymography, the activated form (62-kDa) of MMP-2 was identified in the medium of TMK-MT cell line, but was not detected in TMK-1 cells. Six weeks after orthotopic implantation of TMK-1 and TMK-MT xenografts of nude mouse-subcutaneus tumor into the stomach of nude rats, gastric tumors were found in all the animals. Histologically, the lymphatic invasion was found in the submucosa of the TMK-MT gastric tumors. Lymph node metastasis was not detected in nude rats bearing TMK-1 gastric tumor (0/8). In contrast, lymph node metastasis was detected in five out of 8 rats, bearing TMK-MT gastric tumor. MT1-MMP immunoreactivity was found on the cell membrane and cytoplasm of TMK-MT cells not only in the lymph node metastasis but also in the stomach tumor. These results suggest that MT1-MMP overexpression induced by transfection of its gene may promote lymph node metastasis of transformed cells.

Animals↗
PubMed2000

Successful transplantation of a cadaveric kidney with post-infectious glomerulonephritis.

This report describes a successful renal Tx in a patient with chronic renal failure, caused by dysplastic kidneys, who received a cadaveric kidney with post-infectious glomerulonephritis. Sequential renal biopsies were performed at 12 h before Tx, and at 1 h and on days 8 and 58 post-Tx. Post-operative hematuria disappeared on day 9 and proteinuria on day 13. Normal graft function was observed within 1 month, with histologic resolution. Our study suggests that while the donor kidney facilitates deposition of certain immune reactants, this is a host (environmental) problem and when transplanted into a new host (new environment), the problem is no longer sustained.

Adolescent↗
PubMed2000

Detection of human alpha-defensin-1, an antimicrobial peptide, in the fluid of jaw cysts.

OBJECTIVE: The purpose of this study was to isolate and to identify an antimicrobial peptide, human alpha-defensin-1 (HNP-1) in jaw cyst fluid. STUDY DESIGN: We collected jaw cyst fluid from 22 patients with various jaw cysts and analyzed the peptide components of them by reversed-phase high-performance liquid chromatography (HPLC). HNP-1 in the jaw cyst fluid was identified by the amino acid sequence and the molecular weight. The concentration of HNP-1 in the fluid of various jaw cysts was quantified by HPLC. RESULTS: HNP-1 in the jaw cyst fluid was isolated, purified, and identified. The concentrations of HNP-1 in the jaw cyst fluid ranged from 27.0 to 3725.4 microg/mL. CONCLUSION: HNP-1 was detected in the fluid of various types of jaw cysts.

Adolescent↗
PubMed2000

Hepatitis C virus NS5B RNA replicase specifically binds ribosomes.

Hepatitis C virus (HCV) non-structural protein 5B (NS5B) is an RNA replicase. We expressed full-length NS5B (591 amino acid residues) in Escherichia coli as a fusion protein with maltose binding protein (MBP-NS5B). MBP-NS5B was recovered in the soluble fraction after centrifugation at 40,000 x g and affinity-purified with amylose resin. The purified MBP-NS5B had a high-level of poly (A), oligo (U)-dependent UMP incorporation with a Km of 2 microM for UTP. Surprisingly, the enzymatically active MBP-NS5B was sedimented by ultracentrifugation at 160,000 x g. The pellet contained 16S and 23S ribosomal RNAs, suggesting that ribosomes were associated with MBP-NS5B. Ribosomes and MBP-NS5B were subsequently co-purified on amylose resin. Deletion study revealed that either the N-terminal (amino acid residues 1-107) or the C-terminal (amino acid residues 498-591) region of NS5B were sufficient for this association with ribosomes. We further found that NS5B also bound with human ribosomes. Our results implicate a novel mechanism of coupling between replication and translation of the viral genome in the life cycle of HCV.

Gene Expression↗
PubMed2000

Activation of the interferon-inducible 2'-5'-oligoadenylate synthetase gene by hepatitis C virus core protein.

The effects of hepatitis C virus (HCV) proteins on several signal transduction pathways in human nonneoplastic hepatocyte PH5CH8 cells were investigated using expression vectors encoding HCV proteins derived from HCV-infected human nonneoplastic cultured T-lymphocyte and hepatocyte cells (MT-2C and PH5CH7), which could support HCV replication. The amino acid sequences of HCV proteins obtained from HCV-infected human cells were identical or very close to the consensus sequences of the proteins derived from the original inoculum used for HCV infection. During the course of the study, we found that HCV core protein specifically activated the 40/46-kDa 2'-5'-oligoadenylate synthetase (2'-5'-OAS) gene promoter in a dose-dependent manner in different human hepatocyte cell lines (PH5CH8, HepG2, and PLC/PRF/5). We also found that the activation by core protein was further enhanced in the cells treated with alpha interferon. The expression of E1 or E2 envelope protein or nonstructural NS5A protein did not activate the 2'-5'-OAS gene promoter. We demonstrated that the activation by core protein in the hepatocyte cells was suppressed by antisense RNA complementary to core-encoding RNA. Deletion mutant analysis of core protein and deletion analysis of the 2'-5'-OAS gene promoter have been performed. Finally, we demonstrated that the activation of the 2'-5'-OAS gene occurred at the transcriptional level and furthermore demonstrated that the endogenous 2'-5'-OAS gene was also activated by core protein. This is the first report to show that a viral protein activated the 2'-5'-OAS gene.

2',5'-Oligoadenylate Synthetase↗
PubMed2000

Effects of aging on surfactant forms in rats.

Surfactant present in the alveolar space exists in two major forms: functional large aggregate forms (LA) and nonfunctional small aggregate forms (SA), but there is no information about the changes of surfactant forms and the rate of conversion of LA to SA in the aged lungs. The purpose of the present study was to investigate the developmental aspects of surfactant forms in newborn, young, middle-aged and aged rats, LA and SA were recovered from alveolar lavages of rats. The rate of conversion from LA to SA was then analysed using a surface-area cycling technique. Age-related changes of saturated phosphatidylcholine (Sat-PC) and surfactant protein A (SP-A) pool sizes were also evaluated in alveolar lavages. The alveolar lavages recovered from aged rats contained a significantly higher proportion of LA than did those obtained from young or newborn rats. There was also an age-related decrease in the rate of conversion from LA to SA in vitro. The Sat-PC pool sizes in the alveolar lavages decreased with age, but the SP-A contents were similar between young and aged rats. These results suggested that decreased form conversion may contribute to maintaining functional surfactant pool sizes in the lungs of aged rats.

Aging↗