Biomedical subjects
Publications and source records attributed to Y Ichikawa.
A branched glycopeptide derivative incorporating two D-mannose 6-phosphate residues was prepared by coupling 6-aminohexyl 6-O-[bis(2,2,2-trichloroethoxy)phosphinyl]-alpha-D-mannopyranoside with N-acetyl-L-tyrosyl-L-aspart-oyldi-L-alanine followed by reductive deprotection of the phosphate group.
To clarify the interactions between mononuclear cells and polymorphonuclear leukocytes, and to identify the cytokine(s) that mediate the interaction, the effects of a culture supernatant of LPS-stimulated mononuclear cells on production of arachidonic acid metabolites of polymorphonuclear cells were studied. The culture supernatant of LPS-stimulated mononuclear cells increased production of prostaglandin E2 of polymorphonuclear cells. TNF alpha, but not IL-1, IL-2, IL-6, or IFN gamma, enhanced the prostaglandin E2 production when added in vitro. Additionally, an anti-rTNF alpha monoclonal antibody inhibited the stimulating activity of the culture supernatants. TNF alpha, produced by mononuclear cells, appears to play an important role in the development of inflammation, such as rheumatoid arthritis, by enhancing the arachidonic acid metabolism of the polymorphonuclear cells.
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Using 3-color flow cytometry, we determined the proportions of activated T cells (DR+), including CD4+ cells, CD8+ cells, and their subsets, in the peripheral blood of 17 patients with Sjögren's syndrome (SS). Activated T cells were significantly increased in CD4+ cells, CD8+ cells, and T suppressor inducer (CD4+, Leu-8+), T helper (CD4+, Leu-8-), and T cytotoxic (CD8+, CD11-) subsets, but not the T suppressor/natural killer subset (CD8+, CD11+), in patients with SS as compared with the controls. Furthermore, the proportions of activated T cells in the CD4+, Leu-8- subset, the CD8+ subset, or the CD8+, CD11- subset showed a positive correlation with serum gamma globulin levels in the SS patients. Our findings suggest that a certain immunoregulatory balance between T helper and T suppressor activities is maintained in SS patients, although this balance seems to occur at highly activated levels, and that quantitative changes of some lymphocyte subsets are important factors in maintaining this balance. We discuss the possibility that CD4+, Leu-8+ cells recirculate into peripheral lymph nodes, while CD4+, Leu-8- cells migrate into inflammatory tissues such as salivary glands, since the Leu-8 antigen is reported to be a homing receptor in peripheral lymph nodes. This process might be accelerated in SS, and each T cell subset may further participate in immunologic activation in the lymph nodes or target tissues.
Syntheses of the following compounds are described: 6-(Trifluoroacetylamino)hexyl 2-acetamido-2,6-dideoxy-beta-D-glucopyranoside and 2-acetamido-2-deoxy-alpha-D-xylopyranoside, two allyl 2-acetamido-2-deoxy-alpha-D-glucopyranosiduronic acid derivatives, and several allyl 2-acylamido-2-deoxy-beta-D-glucopyranosides having different acyl groups. These and other compounds were used as inhibitors in the binding assay for the chicken hepatic lectin specific for N-acetylglucosamine. We found that: 1) The inhibitory potency of N-acylglucosamine derivatives decreased progressively with increase in the size of acyl group, 2) absence of either 3- or 4-OH group of N-acetylglucosamine lowered the binding affinity more than 100-fold, and 3) the presence of a negatively charged group (carboxylic acid) at the C-6 position did not lower the affinity. The first two items are similar to the mammalian hepatic galactose/N-acetylgalactosamine lectins, but the last item is in a strong contrast to the mammalian lectins.
We studied the efficacy of cisplatin-based polychemotherapy for adenocarcinoma of the lung. A total of 136 patients were randomized for treatment with either cyclophosphamide, Adriamycin, cisplatin and mitomycin C (CAPM) or mitomycin C, cytosine arabinoside and tegafur (MCT). Radiation was given to the chests of patients at stage III. The differences in the response rate (35% in the CAPM arm and 13% in the MCT arm) were statistically significant (P less than 0.01). However, the significant difference was observed in stage-IV patients (CAPM, 33%; MCT, 4%; P less than 0.001) and not in stage-III patients (CAPM, 40%; MCT, 40%). The median period of survival was 9.5 months for the CAPM arm and 5.5 months for the MCT arm (P less than 0.035, Wilcoxon-Gehan test; P less than 0.1, log-rank test). Improved median survival for the CAPM regimen was demonstrated only by stage-IV patients (CAPM, 10 months; MCT, 5.5 months; P less than 0.025, Wilcoxon-Gehan test; P less than 0.05, log-rank test). The duration of the response, including PRs and NCs, was significantly different depending on the treatment, showing 5 months for the CAPM arm and 3 months for the MCT arm (P less than 0.05). The significant difference was also only observed in stage-IV patients. Myelosuppression was more severe with CAPM than with the MCT regimen. Nausea and vomiting were significantly increased in patients receiving the CAPM regimen. However, all toxicities were acceptable and there were no treatment-related deaths. We concluded that cisplatin-based chemotherapy, CAPM therapy, was of more benefit to patients with adenocarcinoma of the lung than MCT therapy.
1. Cytochrome P-450-linked monooxygenase of mitochondria and microsomes of the cerebrum, cerebellum and pituitary gland of bovine brain were investigated biochemically and immunochemically. 2. The cytochromes P-450scc and P-450(11) beta, NADPH-ferredoxin reductase and adreno-ferredoxin were detected and their enzymatic activities of steroid hydroxylations were found in the bovine brain.
1. An apo-NADPH-adreno-ferredoxin reductase (EC 1.18.1.2) was obtained from bovine adrenocortical mitochondria and its physicochemical properties were investigated. 2. The effects of various substances such as NADPH, FAD and adreno-ferredoxin on the interaction of the apo-reductase were investigated by various column chromatographies. 3. The apo- and holo-reductases were found to be separated by adreno-ferredoxin affinity chromatography. 4. The removal of FAD from NADPH-adreno-ferredoxin reductase did not affect the net charge of the reductase. 5. The values of s20,w of apo- and holo-reductases were 3.8 x 10(-13) sec and 3.9 x 10(-13) sec, respectively. 6. The apo-reductase was more easily denatured by heat treatment than the holo-reductase. 7. FAD, and adreno-ferredoxin and both could protect the apo-reductase from thermal inactivation.
The effect of the anti-rheumatic drug CCA (disodium 4-chloro-2,2'-iminodibenzoate) on the proliferation of T cells activated by PHA was examined. Cell cycle analysis showed that CCA blocked the transition of the cells from G1 to S (progression), but had little effect on the G0----G1 transition (initiation). CCA had no significant effect on IL-2 receptor expression, an early G1 event, but did inhibit transferrin receptor expression, a late G1 event. CCA did not inhibit IL-2 production by PHA-activated T cells, but did block IFN-gamma production at 72 hr after the stimulation. CCA failed to inhibit c-myc mRNA induction, but did delay the decrease in c-myc mRNA levels that normally occurs with the onset of DNA synthesis. These results indicate that CCA inhibits the progression, but not initiation, of human T cell proliferation.
The structure of the Fc fragment of human IgG1 immunoglobulin is compared for the native and recombinant proteins. A recombinant human Fc fragment was expressed by an E. coli system [Kitai K., Kudo T., Nakamura S., Masegi T., Ichikawa Y. and Horikoshi K. (1988) Appl. Microbiol. Biotechnol. 28, 52-56]. The recombinant protein, which presumably lacks oligosaccharides, was used along with the native human Fc fragment obtained by proteolytic digestion of a myeloma IgG1 protein. 1H NMR has been employed along with circular dichroism and fluorescence spectroscopy to discuss the structure of these two types of proteins. It has been concluded that (1) the overall structure of the recombinant protein is quite similar to that of the native protein, which possesses asparagine-linked oligosaccharides, but (2) a significant difference in structure exists in the neighborhood of the glycosylation site. The difference in the effector functions for the two kinds of the Fc proteins has been briefly discussed in terms of the structural change detected by 1H NMR.
The influence of in ovo bursectomy on the levels of J and mu chains in the sera of embryonic and hatched chicks was studied by the dot blotting immunoassay. The results indicated a decrease in the level of J chains during the embryonic stage after treatment with testosterone compared with normal chicks. Testosterone treatment caused a decrease in J-chain levels after hatching which was more marked in reduced-alkylated than in non-reduced sera. In contrast, testosterone caused no significant change in serum levels of mu chains, either in ovo or after hatching. Our findings further present the paradox that although removal of the bursa of Fabricius by testosterone treatment did not impair mu-chain synthesis, B-cell differentiation was suppressed. These observations indicate that in ovo bursectomy selectively inactivates B-cell differentiation as indicated by the induction of immunodeficiency, and results in the failure of J-chain production.
1. Sheep NADPH-ferredoxin reductase (E.C. 1.18.1.2) was purified from the adrenocortical mitochondria. The reductase was typical flavoenzyme and crystallized in ammonium sulfate solution. 2. The properties of the reductase were investigated physicochemically and immunochemically. The minimum molecular weight of the reductase was 52,000 and the reductase has one FAD per mole as a coenzyme. 3. The sheep NADPH-ferredoxin reductase showed a precipitate line against antibody to bovine NADPH-ferredoxin reductase. 4. The compositions and sequences of amino acid residues of this reductase and porcine, bovine, and human enzymes were compared. In spite of differences of mammalian species, the sequence of amino acid residues in the amino-terminal regions were highly homologous. 5. It is suggested that the amino-terminal region may be essential for the function of the NADPH-ferredoxin reductase.
Using ultrastructural immunochemistry, we have determined subcellular localization of J chain molecules in chicken splenic cells. The majority of J chain positive cells (JPC) were lymphoblast-like cells. The data show that J chains predominantly are localized in cytoplasm with a considerable amount distributed on the cell surface. In the cytoplasm, J chains were diffusely expressed. Furthermore, these J chain molecules were clearly seen as cluster type. In addition to the J chain localization of subcellular organelles as described above, J chains were partly found on perinuclear spaces. As J chains are key protein in B cell differentiation into immunoglobulin (Ig) producing cells, these findings might help for studying regulation of B cell differentiation in addition to revealing the molecular assembly of polymeric Ig.
Absorption of 4,4'-methylenebis (2-chloroaniline) (MBOCA) was assessed for five workers over one week in a polyurethane elastomer factory by measuring urinary MBOCA levels by high performance liquid chromatography (HPLC) using an electrochemical detector. Personal air exposure levels of MBOCA ranged from 0.2 to 8.9 micrograms/m3. The mean urinary MBOCA levels at the beginning and the end of the work shift were 3.1-81.5 and 2.4-96.6 micrograms/g creatinine, respectively. The differences between preshift and postshift urinary MBOCA values were not significant in all workers, according to the paired t-test. The urinary levels after a two-day holiday (on Monday morning) were almost equal to those of preshift levels on other weekdays. Urinary excretion of MBOCA was much higher than the estimated MBOCA levels from personal exposure measurements, suggesting that a significant amount of MBOCA is absorbed by routes other than inhalation. These results lend strong support for the need to monitor exposure control by urinary MBOCA measurement.
Treatment by polymyxin B sulfate and ethylenediaminetetraacetate separated a 40 kilodalton (kDa) protein from the nonpigmented Serratia marcescens and even from the nonpigmented bacteria of the pigmented strains, whereas the same treatment separated the 100 kDa protein associated with the pigment formation from the pigmented bacteria. Lysozyme treatment separated the 100 kDa and/or 40 kDa proteins correlated with the pigmented level. The 40 kDa protein was not an outer membrane protein but a flagellin. These results suggest that the flagella formation was inversely related with the pigment formation.
Since the first description of Diffuse panbronchiolitis (DPB) was published, the elevation of serum cold hemagglutinin (CHA) titer in patients with DPB has been reported, but the mechanism of its elevation is not yet clear. We investigated the relationship between the CHA titer and the indexes of inflammation (CRP, ESR, WBC, alpha 2-gl, gamma-gl), immunoglobulin, bacterial species cultured from sputum in 24 cases with DPB. They were diagnosed clinically as DPB by the criteria of the Japanese Ministry of Health and Welfare. We found no correlation between CHA titer and CRP, ESR, WBC, alpha 2-gl, gamma-gl, but there were significant correlations between the change of CHA titer and IgA, IgM. Additionally, CHA titers which were measured when Pseudomonas aeruginosa was cultured from sputum in patients with DPB were markedly high levels. These results suggest that the elevation of CHA titer does not reflect the degree of inflammations, and it occurs by immunological abnormalities.
A study was made on the passive protection against rotavirus-induced diarrhea. Chickens were immunized with bovine rotavirus (serotype 1) and the egg yolk immunoglobulins containing a high titer anti-rotavirus neutralizing antibody (CEYI) was obtained. The CEYI was then orally administered to specific-pathogen-free cats, and the cats were infected with human rotavirus. The cats treated with the CEYI remained clinically healthy after challenge, whereas diarrhea occurred in the placebo-fed cats as control. Virus antigens were detected in feces in all the diarrheal cases in the placebo-fed cats but were only sporadically detected in the CEYI-fed cats. However, the cats were only protected against rotavirus infection by the presence in the gut at the time of infection of the antibody. These results suggested that continuous administration of the CEYI is capable of preventing children from diarrhea induced by human rotavirus infection and viral shedding.
A 37-year-old man who had had no allergic history was admitted to our hospital complaining of high fever, a dry hacking cough and dyspnea. Mycoplasma and Chlamydia mixed infection was diagnosed because of increased antibody titers to simultaneous Mycoplasma pneumoniae and Chlamydia psittaci, however only the Mycoplasma pneumoniae antibody titer was not decreased during the over six months. One month after the onset, bronchial asthma was diagnosed subsequently from for the clinical symptoms of wheeze and cough. Clinical studies of the dual infection and the possibility of Mycoplasma pneumoniae as the probable antigen of bronchial asthma were discussed.