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Biomedical subjects

A Morikawa

Publications and source records attributed to A Morikawa.

At least 217 records · Page 12Linked to original sources
PubMed1991

Purification of recombinant human tumor necrosis factor precursor from Escherichia coli.

To study its biological functions, tumor necrosis factor precursor (proTNF) with a molecular size of 26-KDa was obtained as a recombinant protein from Escherichia coli. The recombinant proTNF was successfully accumulated in the insoluble form, corresponding to about 10-15% of total E. coli proteins. Solubilization, gel filtration and anion exchange chromatography were performed under denatured conditions followed by dialysis in phosphate-buffered saline. These processes removed most of the contaminating bacterial proteins, yielding proTNF with a purity of about 70-80%. This recombinant proTNF is expected to be useful for functional studies on activated macrophages with membrane integrated proTNF.

Blotting, Western↗
PubMed1991

A saponin from callus tissue of Stauntonia hexaphylla.

A new 30-nortriterpenoid saponin was isolated from the callus tissues of Stauntonia hexaphylla. The structure of the saponin (tentatively named mubenoside A) was elucidated as 3 beta,20 alpha-dihydroxy-30-nor-olean-12-en-28-oic acid 3-O-[beta-D-xylopyranosyl(1----2)-alpha-L-arabinopyranosyl(1----3) ]-beta-D- glucopyranoside by means of spectral experiments.

Carbohydrate Sequence↗
PubMed1991

Polyol pathway in tissues of spontaneously diabetic Chinese hamsters (Cricetulus griseus) and the effect of an aldose reductase inhibitor, ONO-2235.

1. Sorbitol and fructose levels were significantly elevated in the lens, the sciatic nerve, the retina and the kidney of diabetic Chinese hamsters and inositol level was significantly decreased in the lens and sciatic nerve of diabetics. 2. The activity of an aldose reductase in the kidney was not different between normal and diabetic Chinese hamsters. 3. An aldose reductase inhibitor (ONO-2235) had no effect in sorbitol, fructose and inositol contents of all these tissues from diabetic Chinese hamsters. 4. These results suggest that diabetic Chinese hamsters produce polyol accumulation in tissues but that there is a clear species-specific difference to inhibition of aldose reductase.

Aldehyde Reductase↗
PubMed1991

Antitumor activity of a novel chimera tumor necrosis factor (TNF-STH) constructed by connecting rTNF-S with thymosin beta 4 against murine syngeneic tumors.

We have shown the in vivo usefulness of a novel chimera tumor necrosis factor (TNF), called rTNF-STH, which was constituted with human thymosin beta 4 and recombinant human TNF-SAM1. Tumor necrosis was induced by intravenous injection of a smaller amount of rTNF-STH (1 x 10(3) U/mouse, 0.67 microgram/mouse) than rTNF-alpha or rTNF-S (1 x 10(4) U/mouse, 2.5-5 micrograms/mouse). Significant antitumor effects of rTNF-STH to Meth A fibrosarcoma, B16 melanoma, MH134 hepatoma, or Lewis lung carcinoma (3LL) were observed by systemic injection of rTNF-STH at the maximum tolerable dose of 1 x 10(4) U/mouse (6.7 micrograms/mouse); this dose did not cause regression of tumors by conventional rTNF-alpha. rTNF-STH showed a significant prolongation of its half-life in serum. The average calculated half-life of the chimera protein is about 110 min, which is 15 times longer than that of original TNF-SAM1 (7.5 min). On the basis of this prolongation of half-life of rTNF-STH and its efficient hemorrhagic necrotic activity, the antitumor effect of rTNF-STH--as compared with that of the known TNF species--is discussed. Findings indicate that use of the chimera protein to alter the N-terminal region of TNF may be a promising approach to obtain molecules that more favorably attack tumors and other diseases than conventional rTNFs.

Animals↗
PubMed1991

Streptococcal adherence to uncoated and saliva-coated restoratives.

The adherence of Streptococcus sanguis and S. mutans to seven restoratives in the presence and absence of an artificial salivary pellicle has been investigated. The physiochemical surface characteristics of the bacteria and of the restoratives were also measured, together with the effect of salivary coating of restoratives. Zeta potential of uncoated restoratives showed a positive correlation with the number of adherent S. mutans cells and S. sanguis cells. S. sanguis showed a positive correlation with the hydrophobicity of uncoated restoratives. The surface hydrophobicity was decreased upon saliva coating, whereas the zeta potential was slightly increased. The contact angles or zeta potentials of saliva-coated restoratives were positively correlated with those of uncoated restoratives. The number of adherent cells of both S. sanguis and S. mutans to saliva-coated restoratives were decreased after the coating. Zeta potential of saliva-coated restoratives showed a positive correlation with the numbers of adherent S. mutans cells, suggesting that non-specific electrostatic interactions have an important role in the adherence of this species.

Bacterial Adhesion↗
PubMed1991

Role of thromboxane A2 in airway microvascular leakage induced by inhaled platelet-activating factor.

We studied the effects of OKY-046 (1, 10, and 30 mg/kg iv), a selective thromboxane synthase inhibitor, and of ICI 192605 (0.5 mg/kg), a selective thromboxane A2 receptor antagonist, on airflow obstruction and airway microvascular leakage induced by inhaled platelet-activating factor (PAF). Extravasated Evans blue dye content was measured as a reflection of airway microvascular leakage. In control animals, PAF caused a significantly higher increase in extravasation of dye and significantly less increase in lung resistance (RL) than histamine. OKY-046 significantly inhibited both changes in RL and airway microvascular leakage after PAF in a dose-dependent manner, whereas it inhibited histamine-induced airway microvascular leakage only at main bronchi, without any significant effect on RL. ICI 192605 significantly inhibited both RL and airway microvascular leakage induced by PAF, but not after histamine. After both PAF and histamine, changes in RL correlated significantly with the degree of microvascular leakage. Airway microvascular leakage and airflow obstruction after PAF, but not after histamine, may be dependent on thromboxane A2 generation.

Administration, Inhalation↗
PubMed1991

Differences in level and avidity of secretory IgA antibodies in breast milk of Swedish, Indian and Japanese mothers to soybean protein.

Colostrum was collected from Swedish, Indian and Japanese mothers. The samples were as a mean, collected 4.00-4.25 days after delivery of term infants. The level of specific IgA antibody to 2S, 7S and crude soybean antigen were measured by the enzyme-linked immunosorbent assay (ELISA). The avidity of the IgA antibodies to 7S soybean antigen was also measured with an ELISA system using different molarities of potassium thiocyanate for elution of the specific IgA antibody from solid phase-bound antigen. The level of specific IgA antibody to 7S and crude soybean antigen in the milk of the Indian mothers was significantly higher than in the milk of the Japanese mothers (p less than or equal to 0.01). In contrast, the avidity expressed as the molarity of KSCN for 50% elution of IgA antibody to 7S soybean antigen in the milk of the Japanese mothers was significantly higher than in the milk of the Indian mothers (p less than 0.01).

Antibody Affinity↗
PubMed1991

Ability of polymorphonuclear leukocytes to generate active oxygen species in children with bronchial asthma. Use of chemiluminescence probes with a Cypridina luciferin analog and luminol.

Airway inflammation with polymorphonuclear leukocytes (PMN) may play an important role in bronchial hyperresponsiveness (BHR). PMN generate superoxide anion (O2-) and other oxygen radicals that can damage lung tissue. We investigated the ability of peripheral PMN of children with bronchial asthma and control subjects to generate O2- and other active oxygen species using a 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one, a highly sensitive and specific chemiluminescence (CL) probe for O2-, and luminol-dependent CL. The ability of PMN of subjects with asthma to generate O2- and other active oxygen species was significantly greater than that of PMN of control subjects when stimulated with opsonized zymosan (OZ), phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine. Furthermore, in the same asthmatic children, the generation of O2- and other active oxygen species was significantly higher with attacks than without attacks when PMN were stimulated with OZ. We also demonstrated that O2- generation correlated with the degree of BHR to inhaled histamine. These results suggest that PMN of asthmatic children, especially those with attacks, generate more active oxygen species than that of control subjects and that airway inflammation caused by O2- may be closely related to BHR in subjects with bronchial asthma.

Adolescent↗
PubMed1991

Effects of antiasthma drugs on superoxide anion generation from human polymorphonuclear leukocytes or hypoxanthine-xanthine oxidase system.

Airway inflammation with human polymorphonuclear leukocytes (PMNs) may play an important role in the pathophysiology of bronchial asthma. Superoxide anion (O2-) and other active oxygen species derived from PMNs cause tissue damage. To evaluate the effects of antiasthma drugs on airway inflammation or antioxidative actions due to the inhibition of O2- generation, we investigated the effects of antiallergic drugs, beta-adrenergic agonists, theophylline and corticosteroids, on the in vitro generation of O2- by human PMNs, using a chemiluminescence (CL) method dependent on a Cypridina luciferin analog (MCLA), a highly sensitive and specific CL probe for O2-. We found that azelastine, one of the antiallergic drugs, and isoproterenol inhibited FMLP-induced O2- generation in a dose-dependent fashion, whereas the other drugs exhibited no such inhibitory action except at very high concentrations. Furthermore, we found that isoproterenol inhibited O2- generation from the hypoxanthine-xanthine oxidase system (an O2(-)-generating system) in a dose-dependent fashion, unlike azelastine and the other drugs. These results suggest that azelastine and isoproterenol inhibit the process of O2- generation from PMNs, while isoproterenol also scavenges O2-. These drugs may be beneficial in the treatment of airway inflammation due to O2- generation in bronchial asthma.

Adolescent↗
PubMed1991

Post-translational processing of tumor necrosis factor production.

To elucidate the mechanism of tumor necrosis factor (TNF) production, we analyzed proteins produced in macrophages sharing the epitope of TNF according to the priming and triggering of TNF production. Rabbit alveolar macrophages primed with Bacillus Calmette-Guerin (BCG) were isolated and cultured in vitro with 35S-methionine, and the proteins produced were analyzed using anti-rabbit TNF monoclonal antibody. Primed with BCG, alveolar macrophages synthesized two proteins with molecular sizes of 50 and 17 kilodaltons (kDa) (p50 and p17) sharing the same epitope with mature TNF within the cells. These two proteins were released into the medium where other proteins were detected without TNF-activity. Cultured with lipopolysaccharide (LPS triggering), the primed alveolar macrophages released TNF-activity into the medium where p17 together with many larger proteins was detected by immunoprecipitation. In vitro translation of messenger ribonucleic acid (mRNA) from BCG-primed macrophages showed that primary TNF has a molecular size of 28 kDa (p28). These results suggest that active TNF of p17 is secreted when triggered via post-translational processing of the precursor molecules synthesized through priming with BCG.

Animals↗
PubMed1991

[11 cases of anaphylaxis caused by grand keyhole limpet (abalone like shellfish)].

We reported 11 cases of patients who developed moderate to severe anaphylactic reactions induced by the ingestion of grand keyhole limpet (GKL) and abalone. Specific IgE-mediated hypersensitivity to these shellfish was demonstrated by history, skin prick test, RAST and immunoblotting. The RAST inhibition technique revealed cross antigenicity between GKL, abalone and keyhole limpet hemocyanin. By immunoblotting analysis, the major antigens of GKL are shown in the MW range of about 38 Kd and 80 Kd.

Adolescent↗
PubMed1991

Intratumoral tumor necrosis factor induction in tumor-bearing mice by exogenous/endogenous tumor necrosis factor therapy as compared with systemic administration of various biologic response modifiers.

The relationship between the induction of tumor necrosis factor (TNF) (as an indicator of inflammatory reaction) in tumor tissues and its antitumor effect was investigated in tumor-bearing mice by using nine biologic response modifiers (BRMs) and by exogenous/endogenous TNF therapy following a previously reported protocol. Close correlation between the induction of TNF-rich inflammation in tumor tissues and the antitumor effect of BRM were observed. The results of this study suggest that the conditions necessary for exerting antitumor effects of biologic response modifiers may be the induction of TNF (50 to 200 U/g) at the tumor lesions at an early stage after BRM administration and maintenance of the detectable amount of TNF (approximately 10 U/g) for more than 6 hours. Tumor necrosis factor should also be induced in the liver and spleen so that its activity can be maintained in the tumor lesions.

Animals↗
PubMed1991

[Development of hen's egg with low antigenicity for allergic patients].

We tried to prepare hen's egg with low antigenicity for allergy patients. First, we examined the effects of pH, heating temperature and time on antigenicity of egg. Dried whole egg solid (DES) was dissolved in the buffer solution adjusted at various pH and heated at 120 degrees C for 10, 20 and 40 min. As a result the antigenicity didn't significantly decrease. Next, DES was treated with succinic anhydride, sodium hydroxide and was heated. The antigenicity of the resultant modified whole egg solid (MES) was much lower than that of heated whole egg solid. Antigenicity was measured precisely by enzyme immunoassay, inhibition ELISA, RAST inhibition and PCA. It was found that the antigenicity of MES was decreased less than 1/1000 of that of DES. Then SDS-polyacryl-amide gel electrophoresis and gel filtration were performed to clarify the degree of the change of egg proteins. The bands and peaks which corresponded to ovalbumin and ovomucoid known to be major allergenic proteins responsible for egg allergy disappeared and new bands and peaks were detected.

Antigens↗
PubMed1991

[Evaluation of Hymenoptera hypersensitivity including large local reactions among forest administration workers in Gunma prefecture].

We used a questionnaire to investigate Hymenoptera hypersensitivity in 715 forest administration workers in Gunma prefecture and measured venom specific IgE antibodies in those who had exhibited large local reactions (LLR). The results were as follows. 1) Almost all, i.e. 660 (92.3%), of the workers, including 156 (23.6%) hypersensitive workers, had been exposed to insect stings and 241 (36.5%) had experienced LLR. 2) Among the hypersensitive workers, 68.9% exhibited systemic reactions after having been stung no more than ten times and 18.2% experienced systemic reactions when they were stung for the first time. 3) About 60% of the hypersensitive workers had been stung on only one site when they exhibited systemic reactions. 4) An evaluation of venom specific IgE titer for the workers who experienced LLR revealed a relatively high rate of RAST positive results to yellow jackets (39.3%) and wasps (36.9%).

Adult↗
PubMed1991

[Immunoglobulin levels, number of eosinophils in the peripheral blood and bronchial hypersensitivity in children with Mycoplasma pneumoniae pneumonia].

We studied the immunoglobulin levels and the number of eosinophils in the peripheral blood during the course of Mycoplasma pneumoniae pneumonia in children. Nineteen children with Mycoplasma pneumoniae pneumonia, including eight asthmatic children, were the study subjects. In eight of them, bronchial hypersensitivity was also measured by the Astograph method in both the convalescent phase and the healing (non-symptomatic) phase. The results were as follows. 1) Total serum IgA and IgM increased in the convalescent phase. 2) The levels of total serum IgE were higher in the acute phase and then decreased gradually. 3) The number of eosinophils in the peripheral blood increased over the acute-to-convalescent phase. 4) Bronchial hypersensitivity increased after Mycoplasma pneumoniae pneumonia, and two asthmatic children who exhibited bronchial hypersensitivity had asthmatic attacks. 5) Bronchial hypersensitivity persisted for over one month in two non-asthmatic children.

Adolescent↗
PubMed1990

Extracellular depolymerization of hyaluronic acid in cultured human skin fibroblasts.

The chain length of [3H]hyaluronic acid synthesized by cultivating human skin fibroblasts in the presence of [3H]glucosamine was investigated. [3H]Hyaluronic acid obtained from the matrix fraction was excluded from a Sepharose CL-2B column irrespective of the incubation period, whereas that from the medium was depolymerized into a constant chain length (Mr = 40,000). The reducing and non-reducing terminals of the depolymerized hyaluronic acid were N-acetylglucosamine and glucuronic acid, respectively. Prolonged incubation produced no oligosaccharides as shown by examination of hyaluronidase digests, suggesting the presence of a novel endo-beta-N-acetylglucosaminidase in cultured human skin fibroblasts.

Cells, Cultured↗