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H Toyoda

Publications and source records attributed to H Toyoda.

At least 109 records · Page 6Linked to original sources
PubMed1999

Reduced sensitivity of HeLa cells to cis-platinum by simultaneous overexpression of copper, zinc-superoxide dismutase and catalase.

The overexpression of catalase or Cu,Zn-superoxide dismutase (Cu,Zn-SOD) did not affect the sensitivity of HeLa cells to cis-platinum. However, the cytotoxicity of cis-platinum was depressed significantly by the simultaneous overexpression of catalase and Cu,Zn-SOD. We concluded that cis-platinum accelerated the generation of superoxide anion in the cells, and the superoxide anion produced was converted into H2O by the cooperative roles of catalase and Cu,Zn-SOD.

Animals↗
PubMed1999

Oral absorption and clearance of partially depolymerized fucosyl chondroitin sulfate from sea cucumber.

Partially depolymerized holothurian glycosaminoglycan (DHG), a fucosyl chondroitin sulfate chains isolated from sea cucumber, was administered by the intravenous and oral routes to experimental animal. After intravenous injection, clearance of DHG, as measured by the postcolumn HPLC, displayed complex kinetics that were not dose dependent. DHG was excreted unchanged in the urine. No degradation products of DHG were detected by either gel filtration or anion exchange HPLC at any time in plasma, indicating that administered DHG is not catabolyzed by mammalian. Anion exchange chromatographic behavior of DHG excreted into urine after oral administration showed that partial desulfation might occur through intestinal absorption. After oral administration of DHG (50 mg/kg), 0.1% of the dose was found in urine collected for 24 hours. More than 5% of intravenously administered DHG (1 mg/kg) was excreted into urine in 24 hours. These results are suggesting that orally administered macromolecules such as DHG are absorbed in the gastrointestinal tract.

Administration, Oral↗
PubMed1999

Chronic hepatitis C: interferon retreatment of relapsers. A meta-analysis of individual patient data. European Concerted Action on Viral Hepatitis (EUROHEP).

Relapse after interferon (IFN) therapy for chronic hepatitis C virus (HCV) infection occurs in 50% of patients after the initial response. The benefit of retreatment with IFN alone has not been assessed in large controlled studies. To assess the effectiveness and the tolerability of IFN retreatment and to identify the optimal second course regimen, we performed a meta-analysis of individual patient's data on a set of 549 patients (mean age 43.8 years; 12.2 SD, men: 65%) who had an end-of-treatment biochemical response to a first IFN course and then relapsed. Retreatment was started within 24 months after the end of the first course. Biochemical end-of-treatment responses (ETR) and sustained responses (SR) were observed in 405 of 549 (73.8%; 95% confidence interval [CI] 70.1-77.5) and in 124 of 549 (22.6%; CI 19.1-26.1) patients, respectively. One hundred seventy-five of 404 patients (43.3%; CI 38.6-48.2) developed an end-of-treatment, biochemical, and virological response when retreated. A biochemical and virological SR to retreatment occurred in 73 of 494 (14.8%; CI 11.7-18) patients. Thirty-two patients (5. 8%; CI 3.5-7.8) stopped retreatment for adverse effects. Biochemical and virological SR was predicted independently by logistic regression analysis using a negative HCV RNA at the end of the first cycle of IFN (P =.01) and by retreatment with a high IFN dose (P =. 03). Age, cirrhosis, genotype, and gamma-glutamyl transferase levels before retreatment were not significant by multivariate analysis. The excellent tolerability of IFN monotherapy retreatment makes it an option for patients who transiently cleared HCV-RNA during their first IFN course. Patients should be retreated with a high IFN dose regardless of the strength of the dose received during the previous course of treatment.

Adult↗
PubMed1999

Purification of the antigenic components of pigeon dropping extract, the responsible agent for cellular immunity in pigeon breeder's disease.

BACKGROUND: Pigeon breeder's disease (PBD) is a lung disease caused by inhalation of antigens derived from pigeons. OBJECTIVE: This study was undertaken to characterize the responsible component of pigeon dropping extract (PDE) for PBD. METHODS: First, crude PDE was applied to SDS-PAGE followed by immunoblotting by using antibodies in bronchoalveolar lavage (BAL) fluid. Second, 9 bands of PDE were separated by SDS-PAGE and used for antigen-induced PBMCs. Finally, amino-terminal sequencing was conducted on an isolated 21-kd protein by 2-dimensional electrophoresis. RESULTS: Immunoblots with BAL fluid from patients with PBD identified 9 bands. Similar patterns were observed by using BAL fluid from 10 control patients (9 with summer-type hypersensitivity pneumonitis or idiopathic pulmonary fibrosis and 1 asymptomatic breeder), except for the 21-kd protein, which was detected in 10 patients with PBD and 1 asymptomatic breeder. The stimulation indices of PBMCs determined by using proteins electroeluted from the 9 bands were higher in patients with PBD than in the 10 control patients. The 21-kd protein was separated into 5 spots by 2-dimensional electrophoresis; these spots were all reactive with BAL fluid from patients with PBD as determined by immunoblotting. The sequence of the 21-kd protein had 57% identity to a Saccharomyces cerevisiae chromosome X reading frame. A synthetic peptide, derived from the amino acid sequence of the N-terminal of the native protein, induced significant proliferation of PBMCs obtained from 5 patients with PBD, but not with PBMCs obtained from control patients. CONCLUSION: The 21-kd protein is the only protein that identified individuals exposed to pigeons by immunoblotting. Only PBMCs from patients with PBD showed significant proliferation to the 21-kd protein and to the synthetic peptide on the basis of the N-terminal sequence of the native peptide. The 21-kd protein will be an important antigen for studies on the epidemiology, diagnosis, and pathogenesis of PBD.

Animals↗
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

Infection with TT virus, a novel transfusion-transmissible DNA virus, in haemophiliacs and in blood products.

We evaluated the characteristics and rate of infection with TT virus (TTV), a novel DNA virus, in Japanese haemophiliacs. TTV DNA was measured in 60 haemophiliacs by semi-nested polymerase chain reaction. Co-infection with hepatitis C virus (HCV), hepatitis G virus (HGV) and human immunodeficiency virus (HIV) was also evaluated. In addition, the rate of detection of TTV DNA in blood products was evaluated. TTV DNA was detected in 35/60 haemophiliacs (58.3%). There were no differences in the backgrounds or characteristics between haemophiliacs with and without TTV infection, except for higher levels of IgG and IgM in patients with TTV infection. In patients infected with TTV of types other than type 1, which are rarely detected in Japan, the rate of co-infection with HCV of imported types was high; TTV of types other than type 1 in Japanese haemophiliacs were probably transmitted by imported blood products. TTV DNA was detected in over half of the blood products tested, but TTV DNA concentrations in these products were lower than in the serum of haemophiliacs.

Adolescent↗
PubMed1999

Reactive lymphoid hyperplasia of liver coexisting with chronic thyroiditis: radiographical characteristics of the disorder.

BACKGROUND: Reactive lymphoid hyperplasia of the liver is an extremely rare entity, with six cases reported so far. METHODS: We encountered a 47-year-old Japanese female with reactive lymphoid hyperplasia of the liver, which coexisted with chronic thyroiditis. The lesion was discovered incidentally as a hypo-echoic mass with a hyper-echoic rim at a routine ultrasonography examination. It increased from 12 to 17 mm diameter in 6 months. Radiological studies, such as contrast-enhanced computerized tomography (CT) and angiography demonstrated a hypervascular lesion. RESULTS: It was consequently diagnosed as a neoplasm with malignant potentiality and she underwent partial hepatectomy. The lesion was composed of small mature lymphocytes which formed prominent lymphoid follicles with germinal centres, scattered plasma cells and stromal fibrosis. Immunohistochemical study revealed polyclonal origins of the involved lymphocytes. DNA analysis for the immunoglobulin heavy gene and the T cell receptor beta gene using Southern blot hybridization showed no monoclonality. The following features have characterized the images in past cases, as well as ours: hypo-echoic mass, occasionally with a rim, in ultrasonography and hypervascularity, shown by angiography and enhanced CT.

Angiography↗
PubMed1999

Hepatocellular carcinoma with spontaneous regression of multiple lung metastases.

Spontaneously regressed lung metastasis of hepatocellular carcinoma (HCC) in a 82-year-old Japanese man with liver cirrhosis was recorded. Multiple nodular lesions of both lungs, up to 1 cm across, were shown on chest X-ray when the clinical diagnosis of HCC was made because of the presence of a liver mass on abdominal computed tomography (CT) scan and high serum alpha-fetoprotein (AFP) value. The lung lesions which were regarded clinically as metastasis of HCC decreased in number and size 7 months later, and subsequently disappeared a further 7 months radiographically. However, the liver mass revealed no reduction on abdominal CT, despite normalization of the serum AFP value, and the patient died 7 months after the disappearance of the lung lesions. The patient refused biopsy for the liver mass and anticancerous treatment during the course of the disease. At autopsy, the liver mass, 13 cm in diameter, histologically featured moderately differentiated HCC. Only one metastasis, 0.5 cm across, was obvious in the left lower lung lobe. In addition, there were 14 minute lesions in both lungs, up to 0.2 cm across, including three with complete necrosis and 11 with histocytic reaction and fibrosis. The necrotic tissue was filled with large ghostly cells that appeared to be debris from a neoplastic tissue, regardless of no viable tumor cells among them. The clinical and autopsy findings highly suggested that the patient developed spontaneous regression of multiple lung metastases of HCC and subsequently left the very small lesions as the vestige. Thus, the histology of these lesions may exhibit a process of the regression as the sequence of events, i.e., a transition from necrosis of the metastatic HCC to its fibrosis. Presence of an effective factor(s) in relation to the regression was unclarified. There has been no reported cases with regression of the only metastasis of HCC in the literature to date.

Aged↗
PubMed1999

Metachronous bile duct cancer in a patient surviving for a decade and undergoing curative surgery twice.

We report a 75-year-old woman with metachronous bile duct cancer who underwent curative resection twice and has survived for a decade. In 1989, she was admitted because her serum alkaline phosphatase level was elevated. Computed tomography (CT) showed a low-density mass, 2 cm in diameter, at the left hepatic duct and intrahepatic bile duct dilatation in the left lobe. We diagnosed the lesion as an intrahepatic bile duct cancer and performed extended left hepatic lobectomy with systematic lymph node dissection. The histological diagnosis was a well differentiated cholangiocellular carcinoma with hepatic hilar and celiac lymph node metastases (T1N2M0, Stage IVB). In 1996, she was re-admitted with obstructive jaundice. CT showed a slightly enhanced mass, 4 cm in diameter, in the pancreatic head. After reducing the jaundice by percutaneous transhepatic biliary drainage, pancreatoduodenectomy was performed. The histological diagnosis of this lesion was a moderately differentiated adenocarcinoma originating from the intrapancreatic bile duct. Ten years after the first operation, she is leading a normal daily life with no cancer recurrence. These findings suggest that repeated curative surgery can result in a long-term survival of patients with metachronous bile duct cancer.

Adenocarcinoma↗
PubMed1999

Interferon treatment of two patients with quadruple infection with hepatitis C virus (HCV), human immunodeficiency virus (HIV), hepatitis G virus (HGV), and TT virus (TTV).

We administered interferon (IFN) to two patients who had quadruple infection with hepatitis C virus (HCV), human immunodeficiency virus (HIV), hepatitis G virus (HGV), and TT virus (TTV), a recently isolated novel DNA virus. Nine mega-units of natural alpha-IFN were administered daily during the first two weeks and thrice weekly during the following 22 weeks (total dose, 720 mega-units). In both cases, serum alanine aminotransferase (ALT) levels decreased during IFN administration but increased thereafter. The concentrations of HCV, HIV, HGV, and TTV declined with the administration of IFN. However, the concentrations of these 4 viruses increased after the cessation of IFN with the except of TTV in patient 2 which disappeared during treatment and did not subsequently reappear. IFN reduced the concentrations of 4 viruses, in an apparently independent manner.

Adult↗
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

Alterations of hairless mouse skin exposed to chronic UV irradiation and its prevention by hydrocortisone.

Ultraviolet-induced alterations of skin were investigated in a murine animal model. Groups of hairless mice were exposed to UV (black light, lambda max 352 nm; UV distribution: 300-310 nm, 0.9%; 310-320 nm, 2.0%; 320-420 nm, 97.1%) for 20 weeks at a dose of 16.3 J/cm2 five times weekly on weekdays. At the end of 20 weeks irradiation, the dorsal skins were biochemically and histologically examined. Ultraviolet caused remarkable increases in amounts of hyaluronan, chondroitin sulfates and dermatan sulfates in skin (microgram/cm2). Interestingly, a significant change in a collagen content (hydroxyproline, microgram/g of dry powder) caused by UV irradiation was not observed, whereas the amount of collagen (hydroxyproline, microgram/cm2) increased remarkably. Histologically, no distinguishable thickening was observed in both upper dermis and lower dermis, but thickening of the epidermis was observed. Furthermore, the histological study indicated that UV irradiation caused a disappearance of crowds of adipocytes, alternative appearance of numerous fibroblasts and accumulation of collagen bundles and hyaluronan in lower dermis. Hydrocortisone, an anti-inflammatory agent, prevented both the fibrosis of lower dermis and the accumulation of the extracellular matrix components. Based on these results, it seems reasonable that UV penetrates into the lower dermis and causes fibrosis there, resulting from the inflammatory responses.

Animals↗
PubMed1999

Fatal liver failure in haemophiliacs with HIV-induced immunodeficiency: observation of six patients.

We observed six cases of haemophiliacs with HIV-induced immunodeficiency who died from fatal liver failure despite the absence of evident cirrhosis. They all had the infection with hepatitis viruses (two patients with hepatitis B and D viruses and four patients with hepatitis C virus) and their CD4 counts were severely decreased. They were much younger than cirrhotic haemophiliacs without HIV. Their serum levels of hyaluronic acid and type IV collagen were lower than those in haemophiliacs with cirrhosis, and were normal. No patients had experienced symptoms or concomitant diseases characteristic of cirrhosis, such as ascites, jaundice, oesophageal/gastric varices or hepatocellular carcinoma, except for one case who had a history of mild ascites. The characteristics of this liver failure were different from liver failure resulting from cirrhosis caused by chronic hepatitis, which suggests liver failure that is specific to patients with immunodeficiency. This kind of liver failure can be a factor threatening survival in patients with HIV infection and with hepatitis virus co-infection in an immunodeficient state.

Acquired Immunodeficiency Syndrome↗