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Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 1,027 records · Page 57Linked to original sources
PubMed1986

Purification and characterization of the active fragment from Bacillus thuringiensis delta-toxin.

Limited tryptic hydrolysis of a partially purified delta-toxin (Mr = 100,000) from Bacillus thuringiensis, has produced a polypeptide fragment of Mr = 60,000 containing the full biological activity. The fragment was the only polypeptide observed in the polyacrylamide-gel electrophoresis of the delta-toxin after treatment with trypsin and could be purified by DEAE-cellulose chromatography. Amino acid and partial sequence analyses indicate that the 60,000 Mr fragment has been derived from the mid-section of the holotoxin peptide; over 80% of Lys, 65% of Pro and 50% of His residues in the holotoxin have been lost in the active fragment. This section must contain the active site since its specific insecticidal activity is approximately twice that of the holotoxin. The active fragment shows complete cross-reactivity with the antiserum raised against the native toxin, and appeared to possess higher thermal stability than the mother protein. It provides a powerful tool for studies of the structure involved in the insecticidal activity.

Amino Acid Sequence↗
PubMed1986

Recombinant human interleukin 1 alpha and beta stimulate mouse osteoblast-like cells (MC3T3-E1) to produce macrophage-colony stimulating activity and prostaglandin E2.

The effects of interleukin 1 (IL-1) on MC3T3-E1 cells (clonal osteoblast-like cells established from mouse calvaria) were studied to elucidate the mechanism of IL-1-induced bone resorption. Recombinant human interleukin 1 alpha (rhIL-1 alpha) and beta (rhIL-1 beta) stimulated PGE2 production in MC3T3-E1 cells in a dose dependent manner. rhIL-1 alpha and 1 beta also stimulated MC3T3-E1 cells to produce macrophage-colony stimulating activity (M-CSA) in a dose-dependent manner. Indomethacin completely abolished PGE2 production but did not affect CSA. These results suggest that bone resorption induced by IL-1s is at least in part mediated by PGE2 produced by osteoblasts, and that M-CSA produced by osteoblasts may synergistically potentiate bone resorption by recruiting osteoclast precursors.

Animals↗
PubMed1986

Close evolutionary relationship between the chromosomally encoded beta-lactamase gene of Klebsiella pneumoniae and the TEM beta-lactamase gene mediated by R plasmids.

Sixty-three percent homology of nucleotide sequence and 67% homology of deduced amino acid sequence were found between the chromosomally encoded beta-lactamase gene of Klebsiella pneumoniae and the TEM beta-lactamase of transposon Tn3. Moreover, 22 out of 24 amino acid residues are identical around the predicted active site. It is therefore suggested that these two kinds of beta-lactamases share a common evolutionary origin. The 0.5 kb DNA fragment of the cloned gene hybridized specifically with the chromosomal DNA of all the K. pneumoniae strains tested which had been isolated in Japan, USA and Europe.

Amino Acid Sequence↗
PubMed1986

Stimulation of prostaglandin E2 and bone resorption by recombinant human interleukin 1 alpha in fetal mouse bones.

Recombinant human interleukin 1 alpha (rhIL-1 alpha) stimulates prostaglandin E2 and bone resorption in cultured forearm bones of fetal mouse in a dose-dependent manner: the minimal rhIL-1 alpha to elicit a significant bone resorption was 1.6 ng/ml (89 pM). The half maximal concentrations to elicit bone resorption and thymocyte proliferation were 3.3 ng/ml (183 pM) and 0.31 ng/ml (17 pM), respectively. The bone resorbing activity induced by IL-1 was partially inhibited by indomethacin and hydrocortisone, and completely inhibited by anti-IL 1-antibody. There was a good correlation between PGE2 production and bone resorption induced by IL-1 alpha. These results suggest that rhIL-1 alpha stimulates bone resorption at approximately 10 times the concentrations necessary for thymocyte proliferation and that PGE2 produced in the bone is at least in part involved in osteoclastic bone resorption.

Animals↗
PubMed1986

Enhancement of the expression of a rat neutrophil-specific cell surface antigen by activation with phorbol myristate acetate and concanavalin A.

A monoclonal antibody against rat neutrophils, RP-1, was produced by hybridizing a mouse myeloma (P3-X63-Ag8.653) with BALB/c mouse spleen cells sensitized with peritoneal neutrophils from Wistar-King-Aptakeman/Hok rats. RP-1 specifically reacted to neutrophils and bone marrow cells from rats of various strains. The expression of an antigen reactive to RP-1 on rat peritoneal neutrophils was enhanced by stimulation with phorbol myristate acetate and concanavalin A. The experimental result that the expression of an antigen reactive with another anti-neutrophil monoclonal antibody was not enhanced by stimulation with phorbol myristate acetate indicates that the antibody-binding capacity of stimulated neutrophils was not nonspecifically enhanced. The enhancement of antigen expression was temperature dependent. A glycolytic inhibitor, 2-deoxy-D-glucose, and an inhibitor of intracellular calcium mobilization, 3,4,5-trimethoxybenzoic acid 8-(diethylamino)-octyl ester hydrochloride, which inhibited hydrogen peroxide release from stimulated neutrophils, did not inhibit enhancement of the expression of an antigen reactive with RP-1.

Animals↗
PubMed1986

Heterogeneous profiles of a factor that renders neutrophils cytotoxic obtained from a concanavalin A-stimulated spleen cell culture in partial purification process.

Concanavalin A (Con A)-stimulated rat spleen cells were cultured in a serum-free conditioned medium. This culture supernatant contained a certain factor(s) that renders neutrophil cytotoxic for various tumor cells. The factor was tentatively termed neutrophil-activating factor (NAF). Rat NAF was partially purified from the serum-free culture supernatant by using ion exchange chromatography of DEAE-Sephadex A-50, gel filtration of Sephadex G-100, and affinity chromatography of Con A-Sepharose 4B. NAF activity was eluted in broad fractions by the ion exchange chromatography and the gel filtration. Moreover, on the Con A column, some NAF activities were bound to the column, but other activities passed through the column. These results showed the heterogeneity or polydispersity of NAF activity in both molecular size and charge-based separation properties. Monoclonal antibodies were produced by fusing BALB/c myeloma cells (P3-X63 Ag8.653) with spleen cells from syngeneic mice immunized with partially purified NAF (pNAF) obtained from the gel filtration. Absorbent beads which were linked with one monoclonal antibody (ANAF-10) partially absorbed NAF activity from supernatants of a Con A-stimulated spleen cell culture. Further purification of pNAF was performed with the use of affinity chromatography of ANAF-10-linked Sepharose. Through these procedures, the NAF activity was concentrated about 10,000-fold. Heterogeneity of NAF activity, however, did not disappear in even this affinity chromatography. On the other hand, 125I-labeled material of the final product migrated to one major band corresponding with an m.w. of about 20,000 as determined by SDS-PAGE analysis, and NAF activity was detected in the same band.

Animals↗
PubMed1986

Specific activation of lymphocytes against acetylcholine receptor in the thymus in myasthenia gravis.

In 13 patients with myasthenia gravis, spontaneous in vitro production of antibody to acetylcholine receptor (AChR) by thymic cells was observed in seven patients, by bone marrow cells in nine, by peripheral blood cells (PBL) in six, and by lymph node cells in nine. The rate of anti-AChR production in culture closely correlated with the serum anti-AChR level. Specific activity of the immunoglobulin (Ig) G spontaneously produced (anti-AChR/total IgG) was about 10-fold higher in the thymus than in bone marrow, peripheral blood, or lymph node cultures. Pokeweed mitogen (PWM) enhanced anti-AChR production only by PBL. With neither thymus nor lymph node cells did PWM stimulate anti-AChR production, although it greatly enhanced total IgG production. In bone marrow, it depressed both, and it appeared that the anti-AChR was derived from long-lived plasma cells that may be responsible for delaying the fall of serum anti-AChR levels after thymectomy. The results suggest that AChR-specific cells are selectively activated in the thymus, and this may help to explain the benefits of thymectomy in myasthenia gravis.

Adult↗
PubMed1986

Acetylcholine release from guinea pig caudate slices evoked by phorbol ester and calcium.

In guinea pig caudate slices preloaded with [3H]choline, superfusion with medium containing Ca2+ and the phorbol ester TPA (12-O-tetradecanoyl phorbol 13-acetate) produced an increase in the Ca2+-dependent, depolarization-evoked release of acetylcholine (ACh), with no significant effect on the evoked Ca2+ influx. The effect of TPA was antagonized by polymyxin B and H-7, both inhibitors of protein kinase C. The combination of TPA and calcium ionophore (A23187) provoked the release of ACh to a level equal to the maximal response induced by depolarizing stimuli. TPA alone had no significant effect on the release of ACh. These results suggest that protein kinase C probably plays a role in transmembrane signal transduction involved in the release of neurotransmitter from nerve terminals in the brain.

Acetylcholine↗
PubMed1986

Aspiration biopsy cytology a highly diagnostic procedure for assessing neck masses, excluding thyroid tumors.

Aspiration biopsy cytology (ABC) was done on one hundred and forty-five patients with cervical tumors, excluding primary tumors of the thyroid and local metastasis of thyroid cancer, during the period of 44 months from 1981-85. Surgery was done on a total of fifty-five patients with lesions evaluated to be malignant and requiring resection. A correlation was determined between the histological diagnosis based on permanent paraffin sections and the diagnosis made by aspiration biology cytology in order to evaluate ABC in terms of accuracy together with its complications and limitations. The false positive rate was 6.6 per cent and the false negative rate was 8.3 per cent. Histologic diagnosis was predictable by ABC in eighty per cent of cases, but difficulty was experienced in predicting the histologic diagnosis in cases of a poorly differentiated malignancy. A few cases of slight subcutaneous bleeding occurred, but seeding implantation of cancer cells was nil. It was confirmed that ABC is a highly diagnostic procedure for assessing cervical tumors. The method is simple, safe and economical.

Biopsy, Needle↗
PubMed1986

Clinical characteristics and prognosis of myasthenia gravis with other autoimmune diseases.

Of 277 patients with myasthenia gravis (MG) who underwent thymectomy, including 78 with thymomatous MG, 33 patients had other autoimmune diseases. The clinical characteristics of MG with other autoimmune disease were investigated. Graves's disease and rheumatoid arthritis were the most common autoimmune diseases seen. The association rate of autoimmune disease in patients with thymomatous MG (3.8%) was significantly lower than that in patients with nonthymomatous MG (15.1%). The positive rate for a germinal center in the thymus was significantly higher in patients with other autoimmune disease than in those without such disease. Thymectomy was effective for MG in patients with an associated disease as well as in those without such a complication. The clinical course of the associated autoimmune disease did not seem to be adversely affected by thymectomy. Therefore, thymectomy should be performed in MG patients with other autoimmune disease.

Arthritis, Rheumatoid↗
PubMed1986

Kaposi's sarcoma in a Korean living in Japan. Review of cases reported in Japanese literature.

An 87-year-old male Korean living in Japan had the typical classic lesions of Kaposi's sarcoma on the extremities. Numerous red-purple nodules and plaques were observed on the edematous forearms and lower extremities. Histologic examination revealed an extensive proliferation of spindle cells and large endothelial cells, which were both positive for factor VIII-related antigens. The patient's sera were positive for IgG antibodies to late antigens of cytomegalovirus and negative for IgM antibodies to late antigens of cytomegalovirus and for IgG antibodies to early antigens of cytomegalovirus. Cytomegalovirus-related antigens were detected in the nucleus or cytoplasm of cells in the biopsy specimens by the anticomplement immunofluorescence (ACIF) test. These results suggest that cytomegalovirus infection might play a role in the development of Kaposi's sarcoma, though it is premature to draw any definite conclusion in this connection. In addition, the characteristics of histologic and clinical findings of Kaposi's sarcoma cases reported in the Japanese literature have been discussed.

Aged↗
PubMed1986

Specificities of human heterophile Hanganutziu and Deicher (HD) antibodies to glycosphingolipids and a glycoprotein.

The specificities of five heterophile Hanganutziu and Deicher (HD) antibody-containing sera from four different cancer patients and one other diseased patients were compared. Three glycosphingolipids and one glycoprotein antigens and their chemically modified derivatives were used. The antibodies of all whole sera showed similar specificities. IgG and IgM antibody fractions of each serum were separated. Although antibodies of the same class showed similar specificities, differences were detected between the specificities of IgG and IgM. IgG antibody specificities were dependent on the hydrophobic (ceramide) group while IgM antibodies were directed more to the terminal sialic acid moiety of the glycosphingolipid antigens. The results suggested that a similar population of IgG-producing lymphocytes is stimulated in patients. Due to the similarities in specificities of HD antibodies, the results of this study will facilitate the future isolation of either IgG or IgM antibody-producing lymphocyte(s) from a patient with HD antibodies and the establishment of a monoclonal antibody through hybridization with a human myeloma cell line.

Antibodies↗
PubMed1986

Dog and rat pancreatic phospholipases A2: complete amino acid sequences deduced from complementary DNAs.

We performed molecular cloning of the cDNAs that encode dog and rat pancreatic phospholipases A2 to predict the primary structures of these enzymes. The deduced amino acid sequences exhibited a highly conservative feature which is common to a group of pancreatic phospholipases A2 from various animal species. Furthermore, the structures of the signal sequences of dog and rat pancreatic phospholipases A2 were predicted, although the assignment of the positions cleaved post-translationally is only tentative at the present time.

Amino Acid Sequence↗
PubMed1986

Two cases of adult T-cell leukaemia.

A 70-year-old male and a 46-year-old female, both living in Japan, were seen because of multiple erythematous papules and plaques on the trunk and extremities. The peripheral white blood cell counts were increased to 30,000-80,000/mm3. The majority of white cells had characteristic lobulated and deeply indented nuclei. The patients and most of their family members had anti-ATLV antibody. Using an OKT series of monoclonal antibodies the tumour cells were found to be T-cells. Trisomy 21 was detected in the first case and ATL virus proviral DNA in the second.

Aged↗
PubMed1986

Excitatory effect of Clostridium perfringens alpha toxin on the rat isolated aorta.

Clostridium perfringens alpha toxin caused contraction of the isolated aorta of the rat in a dose-dependent manner. The contractile action caused by the toxin was inhibited or abolished by calcium antagonists such as nifedipine, verapamil and cinnarizine, or a Ca-free medium, but was not affected by phentolamine, chlorpheniramine, atropine, tetrodotoxin or a low Na medium. The toxin stimulated Ca uptake into the aorta in a dose-dependent manner. 8-N,N'-diethylaminooctyl-3,4,5-trimethoxybenzoate (TMB-8) blocked significantly both the toxin- and noradrenaline (NA)-induced contractions. Trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphtharene sulphonamide (W-7) did not affect the contractile activity of the toxin but blocked the NA-induced contraction. The toxin also stimulated the 32P phosphate labelling of phosphatidylinositol (PI) and phosphatidic acid (PA) in the preparation. These results indicate that the toxin-induced contraction, which is different from that induced by NA, is the result of a direct action of the toxin on the aorta and is due to an increased Ca2+ permeability across the smooth muscle membrane. It is suggested that the contractile response to the toxin is associated with activation of phospholipid metabolism and enhanced entry of Ca into the aorta.

Amino Acids↗
PubMed1986

3,3',5'-Triiodothyronine inhibits iodothyronine-5'-deiodinating activity induced by 3,5,3'-triiodothyronine at equimolar concentrations in cultured fetal mouse liver.

To investigate the rT3 effect on iodothyronine-5'-deiodinating activity (I-5'-DA) in cultured fetal mouse liver, liver on the 19th day of gestation, in which little or no I-5'-DA was detected and, therefore, rT3 was very stable, was cultured in medium containing thyroid hormone-depleted fetal calf serum supplemented with cortisol, insulin, and various concentrations of iodothyronines. After 4-15 days of culture, I-5'-DA in the homogenate was assessed by the amount of iodide released from outer ring-labeled rT3 and expressed as picomoles of 127I- per mg protein/min. I-5'-DA was induced by T3 (10(-9)-10(-8) M) and T4 (10(-7) M). In contrast, rT3 could not induce I-5'-DA at 10(-8)-10(-6) M. Furthermore, rT3 significantly decreased I-5'-DA induced by T3 (10(-8) M) at almost equimolar concentrations (1-5 X 10(-8) M). The inhibitory action of rT3 was reversible and was specific for I-5'-DA; no alteration in malic enzyme activity or intracellular glutathione concentration was detected. The inhibitory effect of rT3 on I-5'-DA was dose dependent, and the enzyme activity decreased with a half-life of 16 h in the presence of 10(-6) M rT3. The inhibitory effect was not due to contaminating rT3 in the liver homogenates. Lineweaver-Burk analysis revealed that the decrease in I-5'-DA was due to a decrease in the maximum velocity, whereas no alteration in Km was detected, suggesting that rT3 decreases the amount of 5'-deiodinase induced by T3. The minimal free rT3 concentration capable of inhibiting the induction of iodothyronine-5'-deiodinase was approximately 10(-10) M, which may be attainable in vivo, as in amnionic fluid. In summary, we have demonstrated that rT3 exerts a strong antagonistic effect against T3 in inducing I-5'-DA in cultured fetal mouse liver.

Animals↗