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T Kumada

Publications and source records attributed to T Kumada.

At least 37 records · Page 2Linked to original sources
PubMed2000

Measurement of furancarboxylic acid, a candidate for uremic toxin, in human serum, hair, and sweat, and analysis of pharmacological actions in vitro.

3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), a candidate for uremic toxin, was measured in human hair for examining a possible utility as indicator of renal dysfunction. The serum concentration of CMPF was much higher (32.3 +/- 2.7 microg/ml, n = 17; mean +/- SEM) in uremic patients aged 40-55 years receiving hemodialysis treatment than in healthy younger subjects (3.61 +/- 0.19 microg/ml, n = 22), aged 18-23 years. However, the hair concentration of CMPF tended to be lower in the patients (6.8 +/- 1.7 ng/10 mg hair) than in the healthy younger subjects (15.8 +/- 4.5 ng/10 mg) and was significantly lower than that in the healthy age-matched subjects (22.4 +/- 5.3 ng/10 mg, n = 12), aged 40-47 years. Since CMPF was measurable in the sweat (4.4 +/- 3.7 ng/mg) collected from six out of seven healthy subjects examined, it was suggested that the contribution of sweat to the measurement of CMPF in hair was considerable. The fact that the uremic patients undergoing hemodialysis therapy had less sweat than healthy subjects may explain the lower concentration of CMPF in the patients' hair. The pathophysiological roles of CMPF in the body were attempted to be explored by using excised guinea pig organs, and human platelets and neutrophils. CMPF showed no remarkable effects in the concentration range of < or =10(-4) M except for only slight suppression of spontaneous contracture of guinea pig tenia coli at 10(-4) M. As far as the organs and tissues examined in the present study are concerned, the biological activity of CMPF itself, if any, may be very weak. Precaution should be taken against the delivery of a substance through sweat to hair when a small amount of substance is attempted to be measured in hair by employing a sensitive analytical method.

Adolescent↗
PubMed2000

Technical aspects of venous stenting in high-grade stenoses using a long guidewire between dual venous access sites.

We describe the technical benefits of the dual-access technique for venous stenting in high-grade stenosis. Stents were implanted successfully with this technique in all patients, although the preceding transfemoral interventions had failed. The dual-access technique is useful to facilitate the intervention when the stenoses are too severe to place the stent through just a single access point.

Aged↗
PubMed2000

Enhanced graft healing of high-porosity expanded polytetrafluoroethylene grafts by covalent bonding of fibronectin.

The effect of covalent bonding of fibronectin on the patency and graft healing of high-porosity expanded polytetrafluoroethylene (ePTFE) grafts was evaluated. Bilateral carotid grafting was performed in ten mongrel dogs using high-porosity (60 microm) ePTFE grafts, 4 cm in length and 4 mm in internal diameter, that either had been pretreated by the covalent bonding of fibronectin (fibronectin grafts) or were untreated (control grafts). The grafts were harvested 4 to 6 weeks after surgery and subjected to macroscopic and light-microscopic observations. There was no significant difference in patency between the fibronectin grafts and the control grafts with rates of 80% and 70%, respectively. The thrombus-free area score was significantly greater in the fibronectin grafts than in the control grafts, at 86.9% vs 34.0%. Furthermore, the pseudointima was better replaced by fibrous tissue in the fibronectin grafts than in the control grafts, being lined with a layer of endothelial-like cells. More transmural tissue ingrowth was evident in the fibronectin grafts than in the control grafts. The covalent bonding of fibronectin improves graft healing by stimulating transmural tissue ingrowth in high-porosity ePTFE grafts.

Animals↗
PubMed2000

Long-term follow-up of sustained responders to interferon therapy, in patients with chronic hepatitis C.

Interferon (IFN) therapy has been proven to induce the normalization of serum alanine aminotransferase (ALT) levels and to eradicate the hepatitis C virus (HCV) in some patients with chronic hepatitis C, and these patients are usually defined as 'sustained responders'. However, there have been some reports of hepatocellular carcinoma (HCC) in these patients, and the development of HCC remains life-threatening in patients who clear HCV. We analysed the long-term prognoses of patients with chronic hepatitis C in whom HCV was eradicated with IFN. We investigated 392 sustained responders to IFN therapy, from 1,277 patients with chronic HCV infection who received IFN treatment at one of our institutions between April 1989 and March 1999. We analysed the medical records and looked for the development of HCC. About 30% of the sustained responders had been lost to follow-up 3 years after the end of IFN therapy, and the follow-up rate of sustained responders was significantly lower than that of non-sustained responders (P < 0.0001). HCC were found in eight patients: in seven patients HCC developed within 5 years after completion of IFN therapy; but in one patient, a single HCC less than 3 cm in diameter was detected between 7 and 8 years after completion of IFN. Of the five patients who had regular medical follow-up, the HCC was solitary, and the patients survived without any evidence of recurrence. Of the three patients who had not been followed-up, two died from HCC and HCC recurred in the third. These results suggest that HCC can develop in sustained responders and that sustained responders should be followed-up closely after completion of IFN so that HCC may be detected at an early stage. The optimal duration of the follow-up period of the sustained responders remains unclear. Additional prospective studies are required in order to establish an appropriate follow-up protocol for sustained responders to IFN.

Adolescent↗
PubMed1999

Mutation patterns for two flaviviruses: hepatitis C virus and GB virus C/hepatitis G virus.

We studied the mutation patterns of hepatitis C virus (HCV) and GB virus C/hepatitis G virus (HGV). Although the mutation patterns of the two viruses were similar to each other, they were quite different from that of HIV. In particular, the similarity of the patterns between HCV or HGV and human nuclear pseudogenes was statistically significant whereas there was no similarity between HIV and human nuclear pseudogenes. This finding suggests that the mutation patterns of HCV and HGV are similar to the patterns of spontaneous substitution mutations of human genes, implying that nucleotide analogues which are effective against HCV and HGV may have a side effect on the normal cells of humans.

Flaviviridae↗
PubMed1999

Functional B-cell response in intrahepatic lymphoid follicles in chronic hepatitis C.

Intrahepatic lymphoid follicle (ILF) formation is one of the most characteristic and commonly observed histological features in patients with chronic hepatitis C. However, little is known regarding whether follicles in the liver belong to functional lymphoid tissues, where B cells are activated, differentiated, and proliferated, or if the lymphocytes are merely infiltrated after recruitment from the secondary lymphoid organs. To ascertain this possibility, we examined the expression of markers for B-cell activation, differentiation, and proliferation in ILFs in patients with chronic hepatitis C using surgically resected specimens, and compared them with specimens of perihepatic lymph nodes by an immunohistochemical technique. Germinal center (GC) formation in the ILFs was frequently found in HCV-positive cases. The distribution of immunoglobulin M (IgM)-, IgD-, and IgG-positive cells and the expression patterns of Ki-67, CD23, or bcl-2 and bcl-6 gene products in the follicles with GC formation in the liver of patients with chronic hepatitis C were similar to those of lymph nodes, indicating that B cells are activated, proliferated, and differentiated in the ILFs with GC formation in patients with chronic hepatitis C. Oligoclonal expansion of B cells in the livers with ILFs was confirmed by an analysis of immunoglobulin heavy chain (IgH) gene rearrangement determined by polymerase chain reaction (PCR). These data strongly suggest that ILFs with GC formation, which are frequently found in patients with chronic hepatitis C, may functionally be the same as those found in lymph nodes with respect to B-cell expansion and maturation.

Adult↗
PubMed1999

Clinical utility of Lens culinaris agglutinin-reactive alpha-fetoprotein in small hepatocellular carcinoma: special reference to imaging diagnosis.

BACKGROUND/AIMS: Blood concentration levels of alpha-fetoprotein like the Lens culinaris agglutinin-reactive fraction (AFP-L3) are a useful marker for predicting the long-term prognosis of hepatocellular carcinoma. This study investigated the relationship between serum AFP-L3 and various imaging modalities. METHODS: Sixty-three patients with small hepatocellular carcinomas < or = 2 cm in diameter were studied. Serum AFP-L3 concentrations were measured by lectin-affinity electrophoresis coupled with antibody-affinity blotting and expressed as % AFP-L3 (the percent of AFP-L3 as total AFP). A clinical "cutoff level" of 10% was used in this study to indicate the presence of hepatocellular carcinoma. Selective hepatic intraarterial digital subtraction angiography (DSA), ultrasonographic angiography with carbon dioxide microbubbles (USAG), and computed tomography during arterial portography (CTAP) were performed to evaluate the hemodynamics of hepatic nodules. RESULTS: Fourteen (22.2%) of the 63 patients were positive for % AFP-L3. The % AFP-L3 levels (n=45, 4.4%) of patients with hypervascular tumors were significantly higher than those (n=15, 0.0%) of patients with isovascular or hypovascular tumors as determined by USAG (p=0.0061). The % AFP-L3 levels (n=53, 4.4%) of patients with a negative portal blood supply were significantly higher than the % AFP-L3 levels (n=7, 0.0%) of patients with a positive portal blood supply as determined by CTAP (p=0.0140). The % AFP-L3 levels of patients with tumors with a long doubling time (DT) were significantly lower than for patients with tumors with a short DT (p=0.0176). CONCLUSION: AFP-L3 is a positive indicator which may be more specific for small advanced hepatocellular carcinoma.

Aged↗
PubMed1999

Why is the interferon sensitivity-determining region (ISDR) system useful in Japan?

BACKGROUND/AIMS: The amino acid sequence of NS5A2209-2248, named the "interferon sensitivity-determining region" (ISDR), has been reported to correlate with responsiveness of interferon (IFN) therapy to patients with the hepatitis C virus (HCV) genotype-1b, by several Japanese authors. However, European authors have failed to find this phenomenon, suggesting a difference in HCV-1b isolates between Japan and Europe. METHODS: We compared the HCV-1b nucleotide sequences of our Japanese patients and those of other countries quoted from GenBank, using the envelope 1 sequence. RESULTS: A phylogenetic tree analysis revealed two characteristic groups from a geographical viewpoint: one group (NJ group) consists of almost entirely non-Japanese isolates, and the other (J group) of almost entirely Japanese isolates. The isolates other than the NJ and J groups are characterized by their specific nucleotide residue, constructing an individual group (W group). Japanese HCV-1b isolates consist of the J group and W group (approximately 40% and 60%, respectively). Comparative study between the two groups in Japanese patients treated with IFN revealed a strong correlation between ISDR type and IFN responsiveness only in the J group, but not in the W group. CONCLUSIONS: These observations convinced us that the existence of the Japan-specific J group is one reason why the ISDR system is useful only in Japan.

Base Sequence↗
PubMed1999

Diversity of nucleotide sequences in hypervariable region 1 of hepatitis C virus in Japanese patients with chronic hepatitis C of unknown mode of transmission.

We evaluated the sequence diversity of the hypervariable region 1 (HVR1) of hepatitis C virus (HCV) in HCV-infected patients in whom the mode of transmission is unknown. The sequence diversity of HVR1 in 26 Japanese patients with chronic HCV infection of unknown mode of transmission (UT) was compared with 17 patients with chronic posttransfusion hepatitis C in whom only a single HCV infection had occurred (PH), and with 18 patients with hemophilia with chronic HCV infection who might have been multiply infected with HCV (HE). The diversity of HVR1 was evaluated by direct sequencing after PCR amplification of HVR1. The sequence diversity of HVR1 was 10.1 +/- 7.7% in UT, 2.7 +/- 2.8% in PH, and 14.6 +/- 6.9% in HE. The diversity of the patients with unknown transmission was greater than that of the posttransfusion hepatitis patients, and in some patients it was similar to that of multitransfused hemophiliac patients (UT vs PH, P = 0.0004; UT vs HE, P = 0.04; and HE vs PH, P < 0.0001). Multiple infections with HCV could have occurred frequently in patients with chronic HCV infection in whom the mode of transmission was unknown, which increased the sequence diversity of HVR1 of these patients.

Adult↗
PubMed1999

Clinical utility of simultaneous measurement of serum high-sensitivity des-gamma-carboxy prothrombin and Lens culinaris agglutinin A-reactive alpha-fetoprotein in patients with small hepatocellular carcinoma.

OBJECTIVE: To evaluate the diagnostic efficacy of simultaneous measurements of high-sensitivity des-gamma-carboxy prothrombin (H-DCP) and Lens culinaris agglutinin A-reactive alpha-fetoprotein (AFP-L3) in small hepatocellular carcinoma (HCC). METHODS: Sixty-one patients with small HCCs < or = 2 cm in diameter and 134 controls (chronic hepatitis: 59 cases; cirrhosis: 75 cases) were examined. H-DCP was measured by electrochemiluminescence immunoassay (cut-off 40 mAU/ml (milli-arbitrary units/ml) and AFP-L3% (percentage of AFP-L3/total AFP) by lectin-affinity electrophoresis coupled with the antibody-affinity blotting method (cut-off 10%). Fifty-six patients were histologically diagnosed and the remaining five patients were diagnosed clinically. RESULTS: Of 61 patients, 27 (44.3%) were positive for H-DCP and 14 (23.0%) were positive for AFP-L3. There was no correlation between H-DCP and AFP-L3%. Nineteen patients (31.1%) had positive H-DCP alone. Six patients (9.8%) had positive AFP-L3 alone, and in eight patients (13.1%) both markers were positive. In combination assay, 33 of 61 patients (54.1%) were positive for either marker; specificity and accuracy were 97.8% and 84.1%, respectively. There was a tendency for the AFP-L3% to be elevated in patients with moderately or poorly differentiated HCC (P= 0.0564) and multiple HCC nodules (P= 0.0316), while the H-DCP showed no elevation related to the tumour type. CONCLUSION: The detection rate of small HCC was improved by combination assay with H-DCP and AFP-L3%. Our results indicate that the markers are complementary and useful for the diagnosis and evaluation of small HCC when measured simultaneously.

Biomarkers↗
PubMed1999

Presence of multiple genotype-specific antibodies in patients with persistent infection with hepatitis C virus (HCV) of a single genotype: evidence for transient or occult superinfection with HCV of different genotypes.

OBJECTIVE: We investigated the significance of multiple genotype-specific antibodies in patients with persistent infection with hepatitis C virus (HCV) of a single genotype. METHODS: Titers of genotype-specific antibodies to group 1 and 2 HCV polypeptides in the NS4 region of HCV were measured in 53 hemophiliacs and 58 nonhemophiliacs who were persistently infected with HCV of a single genotype. In addition, sequence variability in hypervariable region 1 (HVR1) of HCV was evaluated in these patients. RESULTS: The presence of antibodies to both group 1 and 2 polypeptides, reflecting a mixture of serotypes, was more frequent in hemophiliacs (11 of 53 patients, 20.8%) than in nonhemophiliacs (two of 58 patients, 3.4%; p = 0.01). HVR1 sequence variability in 13 patients with mixed serotypes was higher than in 87 patients with a single serotype (21.1 +/- 4.3% vs 8.5 +/- 6.3%; p < 0.01). CONCLUSIONS: A mixture of HCV serotypes was more common in hemophiliacs with persistent HCV infection of a single genotype who were at high risk of exposure to HCV than in nonhemophiliacs, and the sequence variability of the infecting strains was high in these patients. These data are suggestive of the effects of superinfection with HCV of different genotypes. The presence of multiple genotype-specific antibodies to HCV may be evidence of transient or occult superinfection with HCV of different genotypes in patients with persistent infection by HCV of a single genotype.

Adolescent↗
PubMed1999

Usefulness of measurement of Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein as a marker of prognosis and recurrence of small hepatocellular carcinoma.

OBJECTIVE: Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3%) is a recently described marker of hepatocellular carcinoma (HCC), and its usefulness has been demonstrated in many studies. We evaluated the usefulness of serial measurement of AFP-L3% as a marker of prognosis and recurrence after treatment of small HCC. METHODS: AFP-L3% was measured before and after initial treatment in 60 patients with small HCC (maximum diameter < or = 2 cm). AFP-L3% was taken as the ratio of AFP-L3 to total AFP and multiplied by 100%, and levels > or = 10% were considered positive. Outcomes and recurrence were compared between patients AFP-L3%-negative after initial treatment (Group A, n = 43) and patients who were AFP-L3%-positive after initial treatment (Group B, n = 17). RESULTS: Before treatment, AFP-L3% was positive in 14 (23.3%) of the 60 patients. The cumulative survival rate of Group A was significantly longer (p = 0.0091) than that of Group B. The recurrence rate was significantly higher in Group B (p = 0.0104) than in Group A. When recurrence was limited to intrahepatic metastasis, the recurrence rate was significantly higher in Group B (p = 0.0064). However, the recurrence rate of multicentric occurrence did not differ significantly between Groups A and B. CONCLUSIONS: Measurement of AFP-L3% after treatment may be useful for understanding prognosis and recurrence of HCC.

Carcinoma, Hepatocellular↗
PubMed1999

Phase II study of combined administration of 5-fluorouracil, epirubicin and mitomycin-C by hepatic artery infusion in patients with liver metastases of gastric cancer.

This multicenter phase II study evaluated the efficacy of the FEM regimen (5-fluorouracil 333 mg/m(2) each week, epirubicin 30 mg/m(2) once every 4 weeks and mitomycin-C 2.7 mg/m(2) once every 2 weeks) administered by hepatic artery infusion (HAI) for unresectable hepatic metastases of gastric cancer. The response rates were 55.6% (complete response: 3, partial response: 32, no change: 21, progressive disease: 7/63) and the mean 50% survival was 10.5 months. Most responders died due to the progression of extrahepatic lesions. HAI of the FEM regimen induced a high response rate in patients with hepatic metastases of gastric cancer, and the prognosis-determining factor was the existence of extrahepatic lesions in many patients.

Aged↗
PubMed1999

Limitations in attending to a feature value for overriding stimulus-driven interference.

Six experiments were conducted to examine the effect of knowledge of a target for overriding stimulus-driven interference in simple search tasks (Experiments 1-3) and compound search tasks (Experiments 4-6). In simple search when the target differed from nontargets in orientation, a singleton distractor that had an orientation equivalent to that of a target interfered with search for the target. When the singleton distractor was less salient than the target with respect to the target-defining feature, it still caused interference. Such within-dimensional, nonsaliency-based interference also occurred in compound search tasks. In contrast, no interference occurred when a singleton distractor was defined in cross-dimension in a simple search task. When a compound search task was used, the salient distractor interfered with the search for a less salient target. These results are discussed in terms of their applicability to existing models and the limitations of top-down penetrability of a feature processing stage.

Adult↗
PubMed1999

[TT virus(TTV) infection in patients with acute hepatitis].

A novel DNA virus, TT virus(TTV), has been reported in patients with posttransfusion hepatitis of unknown etiology. However association between TTV and acute hepatitis has not been shown. We investigated the prevalence of TTV in acute hepatitis. TTV-positive rates in acute hepatitis A, B, C, cytomegalovirus infection, Epstein-Barr virus infection, and acute hepatitis of unknown etiology were 15.3%, 21.8%, 60.0%, 0%, 10.0%, 22.6%, respectively. There were no significant differences in TTV prevalence between each etiology and healthy blood donors(20.8%). Clinical data were similar between patients with or without TTV. In this study we could not find any difference in the prevalence of TTV between acute hepatitis with known etiologies and that with unknown etiology. TTV did not affect the clinical features of acute hepatitis with known etiologies.

Acute Disease↗
PubMed1999

[Clinical experiences of implantable vascular access device, "Vital Port" for arterial infusion chemotherapy].

We had the opportunity to use "Vital Port", a subcutaneous implantable vascular access port which was developed in the U.S. and has been used clinically in a multicenter study for clinical evaluation. To prevent the result from varying by facility, standardized criteria were made. The access port was implanted in 31 patients, and then intra-arterial infusion chemotherapy was performed. The follow-up period was 4 weeks. No complications were observed in any of the cases. Intra-arterial infusion chemotherapy was carried out without any problem. This port is lightweight and has good biocompatibility, and the clinical results were evaluated highly.

Adult↗