Yoshio Ueno's research while affiliated with Tokyo University of Science and other places

Publications (203)

Article
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This work investigated the effects of co-occurring aflatoxin B1 (AFB1) and microcystin (MC) in aquaculture, using immunohistochemistry and genotoxicity methods. Tilapia (Oreochromis niloticus) were exposed to AFB1 by intraperitoneal and MC (cell extract of Microcystis aeruginosa) by intraperitoneal and immersion routes. The interaction of MC-AFB1 w...
Article
Full-text available
The deterioration of the water quality due to aquaculture is associated with eutrophication, with bloom of cyanobacteria. Microcystis aeruginosa is distinguished as main producer of microcystins (MCs), group of hepatotoxins with tumor promoter potential. In the present work immunohistochemical method for detection of MC in tilapia (Oreochromis nilo...
Article
Full-text available
An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for ochratoxin A (OTA) detection in green, roasted and instant coffees was developed using anti-OTA monoclonal antibody. Immunological reagents prepared were OTA-BSA (4.76,mu g/mL), anti-OTA.7 MAb (2x10(3)-fold dilution) and HRP-anti IgG (10(3)-fold dilution). The detection limit...
Article
The performance of an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) for ochratoxin A (OTA) detection was evaluated in a comparative study with high-performance liquid chromatography (HPLC) analysis using 68 freshly harvested coffee samples from the North of Paraná State, Brazil. The anti-OTA...
Article
Full-text available
Fusarium verticillioides is a primary corn pathogen and one of the main producers of fumonisins, a group of mycotoxins that cause several diseases in animals and probably also affect humans. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on polyclonal antibodies was developed to detect the exoantigen of this fungus in co...
Article
Recently we have reported that T-2 toxin, a trichothecene mycotoxin produced by Fusarium species, is a potent inducer of apoptosis in the human promyelotic cell line HL-60. To clarify the signal transduction pathway of apoptosis primed by T-2 toxin, T-2 toxin-induced apoptosis was investigated in detail using confocal laser microscopy and flow cyto...
Article
By using a highly sensitive enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody, microcystin (MC) concentration was analyzed in environmental water samples (total, 134), collected in 1993-1995 from ponds, lakes, reservoirs, and rivers in Japan, Thailand, Germany, and Portugal. MCs detected in the water samples filtered over a g...
Article
Cyanobacterial toxins, microcystins, have a potent tumor-promoting activity. We investigated the level of microcystins in drinking water collected from 1992 to 1994 in Haimen City, China, where people who drink pond ditch water usually incurred a high incidence rate of hepatocellular carcinoma compared with those who drink well water. High-performa...
Article
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Exoantigens from Fusarium verticillioides strains were analysed by polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA) and Western blot and were used for production of polyclonal antibodies. Rabbits were immunized with exoantigens from strains 97K, 162A and 113F. Polyclonal antibodies against F. verticillioides...
Conference Paper
Tightening diagrams have been well known and utilized to the design of bolted joints in wide applications. The tightening diagram is conceptually illustrated by using two lines. One represents the relationship between the bolt force and the bolt elongation, the other represents that of the clamping force and the compressive displacement of the clam...
Article
Full-text available
Natural fungal and fumonisin contamination were eva luated in 109 freshly harvested corn samples from P araná State and correlated to damaged kernels (%). In add ition, healthy and damaged kernels of 24 corn sampl es were selected in order to compare the mycoflora profile and fumonisin levels. The correlation among protein /lipid content and fumoni...
Article
Immunoaffinity purification coupled with high performance liquid chromatography with photodiode array detection was used to quantify microcystins in fish samples. The immunoaffinity purification method consisted of heat denaturation, pronase digestion, and Sep‐Pak C18 extraction together with subsequent purification using an immunoaffinity column....
Article
A screening for specific amylase inhibitor levels against amylase from Fusarium verticillioides (Fusarium mondiforme), the most relevant mycotoxigenic fungus in corn, was conducted on 37 corn hybrids. The amylase inhibitor levels in these hybrids ranged from 5.5 to 16.0 amylase inhibitor units per gram of corn (AIU/g) in the MASTER and AG5011 hybri...
Article
A case-control study was carried out to investigate the impact of factors including virus infection, aflatoxin B1, microcystins, smoking/drinking and dietary habits as well as genetic polymorphisms of aldehyde dehydrogenase 2 (ALDH2) and cytochrome P4502E1 (CYP2E1), on susceptibility to hepatocellular carcinoma (HCC) in Haimen, China. A total of 24...
Article
A reusable immunoaffinity column for purification of microcystins in lake water was prepared by coupling anti-microcystin-LR monoclonal antibodies to immunoaffinity support. Thanks to spherical shape of the immunoaffinity support Formyl-Cellulofine used in this study, applied solutions passed the column smoothly even when used repeatedly. Reusabili...
Article
The aim of this study was to examine tumor necrosis factor-α (TNF-α) expression and Kupffer cell activation in hepatotoxicity caused by microcystin-LR (MCLR). Mice received a single intraperitoneal injection of 60.0 μg/kg MCLR and were killed at several time points within 24 hours. MCLR caused hemorrhage within 7 hours, followed by hepatocellular n...
Article
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We described the use of image analysis for determination of the intralobular distribution of microcystin-LR (L, L-leucine and R, L-arginine) and compared the results with liver injuries. Gray level was measured in each intralobular region and converted to optical density by using the equation, which was established by employing Kodak gray scales; t...
Article
The natural co-occurrence of fumonisins and aflatoxins was investigated in freshly harvested corn kernels (150 samples, 62 hybrids), acquired from the Central-Southern (27 samples, 21 hybrids), Central-Western (86 samples, 51 hybrids) and Northern (37 samples, 18 hybrids) regions of the State of Paraná, Brazil using enzyme-linked immunosorbent assa...
Article
A cyanobacterial toxin, microcystin-LR (MCLR), is a potent inhibitor of protein phosphatase that disrupts cytoskeleton network in hepatocytes. Conventional transmission electron and immunoelectron microscopic studies were conducted in the liver from mice that received a single dose of MCLR and were sacrificed at 24 hours after dosing. The two types...
Article
We have developed a new clean-up method, which consisted of solid-phase extraction on a Sep-Pak PS-2 (styrene-divinylbenzene copolymer) or Excelpak SPE-GLF (polymethacrylate) cartridge instead of conventional ODS silica gel and silica gel together with following immunoaffinity purification using anti-microcystin-LR monoclonal antibodies. This newly...
Article
Trichothecene mycotoxins are commonly distributed in crop fields in the world, and zearalenone has been found in cereals. Rapid and accurate methods for the determination of these mycotoxins is required to prevent the intoxication of humans, and to contribute to the supply of safe foods and feeds for human and livestock. Gas chromatography–mass spe...
Article
Fumonisin B1 (FB1), produced by the fungus Fusarium moniliforme, belongs to a class of sphingosine analogue mycotoxins that occur widely in the food chain. Epidemiological studies have associated consumption of Fusarium moniliforme-contaminated food with human oesophageal cancer in China and South Africa. FB1 also causes equine leucoencephalomalaci...
Article
Fumonisin B(1) produced by the fungus Fusarium moniliforme is a member of a new class of sphinganine analogue mycotoxins that occur widely in the food chain. Epidemiological studies associate FB(1) with human oesophageal cancer in China and South Africa. FB(1) also causes acute pulmonary edema in pigs and equine leucoencephalomalacia. This disease...
Article
The performance of a monoclonal antibody (MAb)-based indirect competitive ELISA (ICELISA) for fumonisin detection in corn was evaluated using 150 post-harvest corn samples from the April 1995 and March-April 1996 crop, in the State of Paraná, Brazil. Compared to high performance liquid chromatography (HPLC), the correlation coefficient (r) of the r...
Article
We have previously reported that 14-3-3β mRNA was overexpressed as well as c-mycmRNA in aflatoxin B1 (AFB1)-induced rat hepatoma K1 and K2 cells as compared with that of the normal liver tissue. 14-3-3β protein is known to play an important role in cell growth and differentiation through the binding to signal transduction factors. Here we report th...
Article
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Studies were carried out to isolate microorganisms from corn and silage screened for their ability to inhibit F. moniliforme growth (strain 113F) in association with fumonisin detoxification. Among 150 isolates four Gram-positive bacilli and one yeast with inhibitory activity were selected. The inhibition zone ranged from 50 to 72.5 mm using cultur...
Article
Thirty-three strains of Fusarium species from clinical sources including F. solani, F. oxysporum, F. moniliforne, F. proliferatum, F. subglutinans and F. chlamydosporum were examined for their physiological characteristics and mycotoxin production. Of this collection 29 exhibited growth at 37°C and 21 were resistant to cycloheximide. Two strains of...
Article
An enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody was used to determine microcystin (MC) concentrations in water supplies and water plant samples collected between November 1995 and October 1996, from five regions of Paraná, Brazil. In addition, the presence of Microcystis sp. was monitored. Of the 50 samples obtained, 12...
Article
Natural mycoflora associated with fumonisins were analyzed in 150 samples of freshly harvested corn from Central-Southern, Central-Western and Northern regions of the State of Paraná, Brazil and correlated to climatic conditions. The corn samples were frequently contaminated with Fusarium sp. (98.7 to 100%) and Penicillium sp. (93 to 100%), when co...
Article
Chronic oral toxicity of a low dose of microcystin-LR (MCLR) was examined in female BALB/c mice for 18 months. Six-week-old female mice received 20 μg/L of the toxin in drinking water, which is about 200-fold higher than the level in contaminated drinking water. Control mice received water alone. Mortality, clinical signs, body weights, and food an...
Article
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The objective of this study was to elucidate whether microcystin-LR (MC-LR), a hepatotoxic blue-green algal toxin in drinking water, is carcinogenic or possesses the ability to modulate aflatoxin B1 (AFB1)-induced hepatocarcinogenicity. In a medium-term liver bioassay, male Fischer 344 rats were given a single i.p. injection of diethylnitrosamine (...
Article
To develop an ultrasensitive immunoassay for microcystins (MCs), a group of heptapeptide hepatotoxins produced by cyanobacteria, we produced monoclonal antibodies (MAbs) which specifically recognize the immune complex (IC) formed by an anti-MC MAb (MC MAb) and MCs. The use of the anti-IC MAb (IC MAb) as the secondary antibody made it possible to de...
Article
Using monoclonal anti-fumonisin B1 antibody (anti-FB1) and avidin-biotin-peroxidase system, liver and kidneys of broiler chicks were evaluated for the detection and distribution of fumonisins (FBs). One hundred and fifty micrograms of FB1 or culture extract of Fusarium moniliforme str. 113F containing 150 microg of FB1 and 4 microg of FB2 were admi...
Article
There have been many reports on the formation of apoptotic bodies, but little is known about the cellular pathological processes and the morphological changes involved. We induced apoptotic cell death by administering nivalenol (NIV), a trichothecene mycotoxin produced by Fusarium species, and investigated the ultrastructural process of formation o...
Article
Hepatitis B virus (HBV) infection is closely related to the development of not only acute or chronic hepatitis, but also hepatocellular carcinoma. Among the HBV genes, the X gene has been implicated in the carcinogenicity of this virus as a major causative factor by its ability to activate viral and cellular genes in trans via protein-protein inter...
Article
Wilms' tumors occur most frequently in swines as sporadic tumors. To clarify the role of WT1 gene in the genesis of Wilms' tumors and genitourinary development, we have isolated the porcine homologue of the human WT1 gene (pWT1) and analyzed its expression in various organs including the kidney. The open reading frame of pWT1 cDNA was extremely hom...
Article
Full-text available
The relationship between the intralobular sites of hepatotoxic injury and the distribution of microcystin-LR (MCLR), an inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A), was examined using an immunohistochemical method with a monoclonal antibody specific to MCLR on the livers of mice receiving a single i.p. injection of the MCLR. Immunoblott...
Article
Microcystins (MCs), a group of heptapeptide hepatotoxins produced by cyanobacteria, are suspected as tumor-promoter contaminants of environmental water. We have previously developed an enzyme-linked immunosorbent assay (ELISA) for MCs based on an anti-MC MAb (MAb-mc). We describe here the production of anti-idiotype MAbs (MAb-ids) which react with...
Article
A trial for chemotaxonomic analysis of toxigenic Fusarium species was performed by an introduction of restriction fragment length polymorphisms based on the selected DNA probes of Fusarium sp. Fn 2B strain, a well-known producer of trichothecene mycotoxins nivalenol and fusarenon-X. A total DNA of F. Fn 2B was prepared from the protoplast suspensio...
Article
Transcriptional activation of the human c-myc gene by SV40 large T antigen was examined using HepG2 cells by co-transfecting a T antigen expression plasmid with a myc-CAT construct containing the 2.3-kb upstream region from the P1 promoter and the P2 promoter region fused to the CAT gene. T antigen increased the basal activity of the P2 promoter re...
Article
We established a hybrid baculovirus-T7 RNA polymerase system for transient expression in mammalian cells. Two recombinant baculoviruses carrying cDNA of bacteriophage T7 RNA polymerase, with or without a nuclear localization signal, under the control of a mammalian promoter were constructed. High level expression of T7 RNA polymerase was observed i...
Article
The natural occurrence of aflatoxin B1 (AFB1) and ochratoxin A (OTA) has been surveyed in 47 samples of commercial green coffee beans. Samples were collected in Nagoya City, Japan, during 1988–93. Using a combination of immunoaffinity chromatography and high‐performance liquid chromatography analysis, AFB1 and OTA were quantified with detection lim...
Article
Full-text available
An enzyme-linked immunosorbent assay (ELISA) was developed for direct quantitation of microcystins (MCs), a group of freshwater cyanobacterial toxins. An anti-MC monoclonal antibody exhibiting broad cross-reactivity to major MC derivatives was used. The detection limit and linear range of the ELISA standard curve with microcystin-(leucine-arginine)...
Article
Peptide bond cleavages by vapors composed of various from aqueous solutions of perfluoric acid were studied using synthetic peptides and proteins, and specific conditions were established for peptide bond cleavages including a novel cleavage of the glycyl-threonine bond. The peptide bonds on the aminosides of serine residues were cleaved by exposur...
Article
By histopathologic, electron microscopic, and immunochemical observation, the mechanism of cellular death was investigated in thymus, spleen, and liver of mice given intraperitoneally sublethal doses of T-2 toxin, a trichothecene mycotoxin. In the thymus and spleen of mice given 5.0 mg/kg body weight of T-2 toxin and killed 12 hours later, a massiv...
Article
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Microcystin-LR (MCLR) is a hepatotoxic peptide produced by Microcystis aeruginosa, an alga found worldwide in reservoirs for drinking supply; however, acute oral toxicity of purified MCLR remains unknown. Therefore, a single dose of MCLR (more than 95% purity) ranging from 8.0 to 20.0 mg/kg body weight was orally given to female 6-week old BALB/c m...
Article
It has been reported that T-2 toxin, a trichothecene mycotoxin produced by Fusarium species, induces cellular destruction in bone marrow and thymus cells, followed by reduced numbers of peripheral white blood cells, and this mycotoxin evokes apoptotic cell death in human peripheral blood lymphocytes (hPBLs). To clarify a possibility that the affect...
Article
The production of trichothecene mycotoxins in Fusarium sp. Fn 2 (NRRL 3509), originally identified as F. nivale was reexamined in details. Shake flask cultures with peptone-sucrose-yeast extract medium produced fusarenon-X (FX=4-acetyl-nivalenol) and diacetoxyscirpenol (DAS) as major products, along with other trichothecenes as minor products, incl...
Article
The hepatic metabolism of microcystins (MCs), potent cyclic peptide hepatotoxins produced by cyanobacteria, was studied by ip injection in mice and rats. An immunoaffinity purification method using an anti-MC-LR monoclonal antibody showed a remarkable effect on the removal of contaminants in the hepatic cytosol and enabled us to analyze MCs and the...
Article
Peptidyl-prolyl-cis-trans isomerase catalyzes the interconversion of the cis and trans isomers of the proline-containing polypeptides and the folding process of proteins. This protein was known to be cyclophilin which has high binding affinity for cyclosporin A, a cyclic undecapeptide of fungal origin with potent immunosuppressive property agent. T...
Article
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An epidemiological survey for the causes of a high incidence of primary liver cancer (PLC) in Haimen city, Jian-Su province and Fusui county, Guangxi province in China, found a close correlation between the incidence of PLC and the drinking of pond and ditch water. With an aim to clarify whether microcystins (MC), a hepatotoxic peptide produced by...
Article
Full-text available
In this study, we sequenced a new type I ribosome-inactivating protein, trichoanguina, from the seeds ofTrichosanthes anguina (snake gourd). Trichoanguina is a basic glycoprotein having an apparent molecular mass of 35.0 kD and possessing strong ribosome-inactivating activity. Trichoanguina was cleaved with cyanogen bromide and partially digested w...
Article
The effect of gamma-ray irradiation and camptothecin (CAM) on human colorectal adenocarcinoma (LS 174T) growth was examined. On inhibition of DNA synthesis of LS 174T cells, almost all combined treatments presented a synergistic effect, excepting that the additive effects were shown at the lowest or the highest doses of CAM prior to the gamma-ray (...
Article
Peptidyl-prolyl-cis-traps isomerase (PPIase) catalyzes the cis-trans isomerization of prolyl peptide bonds in polypeptides and the foldeng process of proteins. This protein was known to be cyclophilin which has high binding affinity for cyclosporin A, a cyclic undecapeptide of fungal origin with potent immunosuppressive agent. The primary structure...
Article
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Employing monoclonal antibody (mAb) AL. 2 reactive for aflatoxin B1-lysin adducts (AFB1-Lys), biotin-conjugated affinity purified anti-human serum albumin (HSA) antibody, and streptoavidin-conjugated horseradish peroxidase (HRP), the sandwich ELISA (sELISA) AFB1-HSA adducts was constructed. In this sELISA, AFB1-HSA adducts in crude albumin fraction...
Article
Full-text available
Novel monoclonal antibodies (mAb) against fumonisin B1 (FB1) were prepared and applied to an indirect competitive ELISA (ic-ELISA). BC6F1 female mice were immunized with a FB1-keyhole limpet hemocyanin conjugate (FB1-KLH). Trials of cell fusion yielded four hybridomas secreting mAb reactive with fumonisins (FB1-1, 2, 3, 4). FB1-2 mAb showing the hi...
Article
To determine whether promotion of thyroid proliferative lesion development is more effectively achieved by increasing dose treatment with a goitrogen than with continuous administration, male F344 rats initiated with N-bis(2-hydroxypropyl)nitrosamine (DHPN, 2,800mg/kg body weight, single s. c. injection) were given water containing 0.1% sulfadimeth...
Article
Natural occurrence of Fusarium mycotoxins (trichothecenes and fumonisins) and aflatoxin B1 (AFB1) were surveyed in 32 com samples, harvested in 1993 and randomly sampled in 1994 in several districts of Hanoi, Vietnam. Com samples were first milled into fine powder, extracted with methanol-water (3:1) and the crude extracts obtained from the same sa...
Article
Peptidyl-proprylyl cis-trans isomerase (PPIase) activity was observed from crude extract of Fusarium sporotrichioides. Proteins from this fungi were separated by two-dimensional polyacrylamide gel electrophoresis and more than one thousand protein spots were separated. Two cytosolic PPIases were found by the N-terminal sequencing from the two separ...
Article
Proteins from Fusarium sporotrichioides M-1-1, a T2-toxin-producing strain, were separated by two-dimensional polyacrylamide gel electrophoresis. One thousand two hundred and forty-four protein spots were resolved and 103 protein spots were subjected to N-terminal sequencing. Fifty-eight protein spots were sequenced and 48 proteins were observed to...
Article
To determine whether production of thyroid proliferative lesions would be enhanced by intermittent rather than continuous treatment with a goitrogen, male F344 rats initiated with Nbis(2-hydroxypropyl)nitrosamine (DHPN, 2800 mg/kg body weight, single s.c. injection) were given water containing 0.1% sulfadimethoxine (SM) for 20 weeks (group 1) or 0....
Article
Sodium 5,6-benzylidene ascorbate (SBA) is a conjugate of ascorbic acid (Asc) with benzyaldehyde. It has been found that the antioxidant activity of SBA is more stable and has a longer lifetime in living cells and organs than Asc. In this study, we investigated the effect of SBA on the induction of melanin in cultured melanoma (B-16) cells irradiate...
Article
Luteoskyrin is a hepatotoxic and hepatocarcinogenic bisdihydroanthraquinone produced by Penicillium islandicum Sopp. By observing the EPR spectra of DMPO-spin adducts and luteoskyrin semiquinone radical, we investigated in vitro whether luteoskyrin is reduced to its semiquinone radical leading to the generation of active oxygen species in redox sys...
Article
Full-text available
Based on the DNA fragmentation profile in gel electrophoresis and the morphological changes in electron microscopy, the induction of apoptotic nuclear changes by mycotoxins and other microbial products, in total 31 chemicals, was investigated in HL-60 human promyelotic leukemia cells, along with the cytotoxicity tests with 3-[4,5-dimethylthiazol-zy...
Article
Six monoclonal antibodies (MAbs) to microcystin-LR (MCLR), a cyclic heptapeptide hepatotoxin isolated from the cyanobacterium Microcystis aeruginosa, were produced. They showed the protective effects on hepatotoxicity of MCLR in vitro and in vivo, and on the inhibition of protein phosphatase by MCLR. Competitive enzyme-linked immunosorbent assays w...
Article
Peptidyl-proprylyl cis-trans isomerase (PPIase) activity was observed from crude extract of Fusarium sporotrichioides. Proteins from this fungi were separated by two-dimensional polyacrylamide gel electrophoresis and more than one thousand protein spots were separated. Two cytosolic PPIases were found by the N-terminal sequencing from the two separ...
Article
Twenty-seven strains of Aspergillus niger group stored in the Institute for Fermenta-tion, Osaka (IFO) were examined for their ochratoxin A (OTA) producibility. TLC and HPLC analyses revealed the production of OTA by 5 out of the 27 strains, A. awamori var. fumeus IFO 4122, A. usamii IFO 8875, 8876, 8877, and A. usamii mut. shirousamii IFO 6082. Th...
Article
To study the interaction and the role of the metal ion in the reaction catalyzed by Escherichia coli ribonuclease HI (E. coli RNase HI), substrate analogues containing a phosphorothioate linkage or 2'-modified nucleosides at the cleavage site were used. In the presence of Mg2+, Mn2+, Co2+, Zn2+, or Cd2+, the phosphorothioate linkage with the RP-con...
Article
A series of DNA-linked ribonucleases H with DNA adducts varying in size and sequence, ranging from heptamer to nonamer, were constructed and examined for their ability to cleave the 12-base RNA (5'-CGGAGAUGACGG-3') site-specifically. The DNA-linked RNase H with the 9-base DNA (5'-GTCATCTCC-3') cleaved the 12-base RNA specifically at A6-U7. Kinetic...
Article
Ribonuclease H (RNase H) recognizes a DNA-RNA hybrid duplex and catalyzes the hydrolysis of the phosphodiester linkages in only the RNA strand. Previously, we developed a method to cleave RNA in a sequence-dependent manner using RNase H and a complementary oligonucleotide containing 2'-O-methylribonucleosides. Since cleavage is restricted to a sing...
Article
Time course changes in serum TSH and quantitative data for thyroid proliferative lesions in male F344 rats administered N-bis(2-hydroxypropyl)nitrosamine (DHPN: 2000 mg/kg body weight, single s.c. injection) followed by 0.1% thiourea (TU), were assessed at weeks 1, 2, 4, 8, 12 and 16 of treatment. The serum T4 level in the TU group was markedly dec...
Article
ADNA-linked RNase H (Hybrid Enz-1) (Kanaya et al. (1992) J. Biol. Chem. 267, 8492-8498), in which dGTCATCTCC was attached to E. coli RNase H via a covalent linker of 21 A, was altered to improve the site-specific RNA cleavage by increasing the linker length. The sizes of the linkers on these hybrid enzymes (Hybrid Enz-2, -3, and -4) differed by 3 A...
Article
The structural stability due to a disulfide bridge between Cys77 and Cys95 of the wild-type human lysozyme is partly recovered by a putative hydrogen bond introduced in to the mutant human lysozyme C77/95S, where Cys77 and Cys95 have been replaced by serines (Yamada et al. (1994) Biol. Pharm. Bull., 17, 192 (1994). In order to understand quantitati...
Article
Fusarium crookwellense was isolated for the first time in Japan from scabby wheat harvested in Hokkaido in 1991. Four isolates were obtained and examined for their mycological features on culture media, mycotoxin production, and pathogenicity to wheat and barley. The texture of fungal colonies and the morphology of macroconidia on a potato dextrose...
Article
Amino acid substitutions were examined to increase the stability of the mutant human lysozyme C77/95A by filling the cavity created by this mutation. To modulate the cavity with hydrophobic amino acids or by the formation of a hydrogen bond, five amino acid-substituted mutants, C77AC95L, C77AC95I, C77LC95A, C77IC95A and C77/95S, were designed and c...
Article
A preliminary survey for the natural occurrence of Fusarium mycotoxins--nivalenol (NIV), deoxynivalenol (DON) and zearalenone (ZEN)--in cereals imported mostly from Australia to Papua, New Guinea (PNG) in 1991 was carried out by TLC, GLC, and HPLC analysis. The data have revealed various kinds of cereals and cereal flours, such as wholemeal flour,...
Article
A survey of AFM1 residues in 58 commercial milk powder samples was carried out using an enzyme‐linked immunosorbent assay (ELISA) based on a monoclonal antibody against aflatoxin M1 (AFM1). The samples were collected from the USA (10), China (28), Italy (14), New Zealand (3) and Poland (3). The ELISA was performed without the need for clean‐up proc...
Article
Full-text available
To determine the reasons for the natural occurrence of nivalenol in the northernmost area of Japan, scabby wheat was harvested from 19 crop fields in Hokkaido. Mycological surveys and analysis for mycotoxin contamination were performed. Among 13 wheat grain samples harvested in seven locations, 9, 2, and 6 samples were positive for deoxynivalenol,...
Article
A modified mixed lymphocyte reaction (MLR) assay was developed to screen immunosuppressive agents. In the MLR, irradiation of splenocytes with UV light was employed for the preparation of stimulator cells, and the highest response was observed with the combination of splenocytes of C3H/He mice as a stimulator and those of C57BL/6 as a responder. Th...
Article
The effects of rhG-CSF on T-2-induced leukopenia and lethal toxicity in mice were investigated. First, T-2 was administered by gavage to adult male mice at a dose of 3 mg/kg b.w. daily for 7 days, and rhG-CSF was given i.p. in daily dose of 10 or 30 micrograms/kg b.w./day, beginning on the 2nd day, for 5 days. The peripheral WBC of mice receiving T...
Article
A region of human immunodeficiency virus type 1 (HIV-1) genomic RNA known to interact with the viral nucleocapsid protein is one of the crucial components for retroviral genomic RNA packaging. We have investigated the secondary structure for this RNA packaging signal of HIV-1 using RNA mapping techniques and extensive computer analyses. Our results...