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Biomedical subjects

H Okada

Publications and source records attributed to H Okada.

At least 865 records · Page 48Linked to original sources
PubMed1989

Two forms of guinea pig factor B of the alternative complement pathway with different molecular weights.

Two forms of guinea pig factor B (B) of the alternative complement pathway with different mol. wts (Mr) have been isolated from plasma and characterized. The Mr of the two B species, tentatively termed B1 and B2, were estimated to be about 100,000 and 96,000, respectively, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Incubation of B with guinea pig C3 and human factor D (D) in the presence of Mg2+ generated two cleavage fragments of B, namely Ba and Bb. Although the Bb fragments showed the same migration corresponding to an Mr of 62,000, Ba fragments showed different mobilities corresponding to an Mr of 38,000 from B1 and 34,000 from B2. Digestion of B1-Ba, the Ba fragment derived from B1, and B2-Ba, the Ba fragment derived from B2, with endoglycosidase F resulted in a band at Mr 30,000 on an SDS-PAGE in both cases, indicating a difference in structure of the asparagine-linked oligosaccharide moiety in B1-Ba and B2-Ba. No difference in antigenicity was noted between B1 and B2 on immunodiffusion with anti-B sera. Immunoblotting analysis showed that all individual Hartley guinea pigs examined in this study possessed both B1 and B2 at similar levels, as determined by the intensity of staining of their sera. Furthermore, treatment of their serum with zymosan led to the generation of two Ba species corresponding to the Ba fragments from B1 and B2. The capacity to form C3/C5 convertase, as determined by hemolytic assay, was found to be similar between B1 and B2. Furthermore, kinetics of the decay of C3 convertase showed the same half-life of 3.0 min at 30 degrees C. The NH2-terminal amino acid sequences of B1 and B2 and their Bb fragments were determined and found to be identical.

Amino Acid Sequence↗
PubMed1989

In vivo and in vitro effects of the antifungal agent miconazole on estrogen biosynthesis in human breast cancer.

This study was undertaken to investigate whether miconazole (MCZ), an antifungal agent, inhibits aromatase activity in human breast cancer tissue preparations (n = 6). Aromatase activity in breast cancer tissue was significantly suppressed by an addition of MCZ (1 microM). The aromatase inhibition rate of MCZ was in the range 15-58%. The change of androgen and estrogen levels was also examined in peripheral blood after administering MCZ (200 mg) intravenously to four patients both with breast cancer and two with systemic fungal infection. Serum androstenedione and testosterone levels fluctuated only little. However, serum estrone and estradiol levels tended to decrease after administration of MCZ. These results suggest that MCZ may be useful in the treatment of breast cancer.

Adenocarcinoma, Papillary↗
PubMed1989

Purification of murine IgG monoclonal antibodies by precipitation with caprylic acid: comparison with other methods of purification.

Purification of murine IgG monoclonal antibodies from ascitic fluid by precipitation with caprylic acid was compared to that: 1) by sequential precipitation with caprylic acid and (NH4)2SO4; 2) by affinity chromatography on either antiidiotypic monoclonal antibodies or antimouse IgG xenoantibodies; and 3) by sequential (NH4)2SO4 precipitation, ion exchange chromatography and high pressure liquid chromatography (referred to as HPLC). In terms of yield of antibodies, precipitation with caprylic acid is comparable to sequential precipitation with caprylic acid and (NH4)2SO4, but superior to affinity chromatography on antibodies and to HPLC. In terms of purity of antibodies, precipitation with caprylic acid is less efficient than the other three methods. It should also be noted that precipitation with caprylic acid is associated with a reduction in the affinity of some antibodies and is not suitable to purify murine IgA and IgG3.

Animals↗
PubMed1989

A novel membrane glycoprotein capable of inhibiting membrane attack by homologous complement.

Neuraminidase-treated human erythrocytes become sensitive to haemolysis by heterologous serum via activation of the alternative complement pathway (ACP), while remaining insensitive to homologous serum because of the presence of inhibitors on the cell membrane. We obtained a monoclonal antibody which renders the neuraminidase-treated erythrocytes sensitive to haemolysis by homologous human serum via the ACP. This antibody reacts with a 20 KDa membrane glycoprotein which interferes with the terminal stage of complement action on cell membranes. The 20 KDa protein is anchored to the membrane via phosphatidylinositol.

Antibodies, Monoclonal↗
PubMed1989

Effect of combined intrapleural administration of Lactobacillus casei (LC9018) and adriamycin on experimental malignant pleurisy in mice.

The combined effect of Lactobacillus casei YIT9018 (LC9018) and adriamycin (ADR) on malignant pleurisy was investigated using an experimental model in BALB/c mice in which Meth A fibrosarcoma cells were intrapleurally implanted. The control mice died from dyspnea due to pleural effusion, before significant growth of tumor nodules could be achieved in the thoracic cavity. Intrapleural (ipl) administration of LC9018 (20-200 micrograms/head) on days 1 and 5 reduced the effusion volume and induced pleural adhesions in a dose-related manner. A statistically significant and reproducible prolongation of survival was observed at a dose of LC9018 200 micrograms/head: increase of lifespan (ILS) values of 15-39% were obtained. An ipl administration of ADR (2-4 mg/kg) on day 1 was also effective in prolonging survival without severe toxicity (ILS values of 100-122%). The combined use of ADR and LC9018 induced a high incidence of pleural adhesions, a delay in effusion accumulation, and an additive prolongation of lifespan (ILS values of 133-178%), compared with ADR monotherapy. In the combination therapy group, a marked and continuous ipl exudation of neutrophils, macrophages, and lymphocytes was observed with a significant decrease in pleural tumor cells. These findings suggest that ipl administration of LC9018 enhances the effect of ADR, probably through both host-mediated tumoricidal activity and sclerosing effects on the pleura.

Animals↗
PubMed1989

Tumor cells treated with vaccinia virus can activate the alternative pathway of mouse complement.

Vaccinia virus has been shown to render mouse tumor cells highly immunogenic. Since we have demonstrated that induction of complement activating capacity on guinea pig tumor cells by Sendai virus infection causes the tumor cells to become immunogenic, we assumed that vaccinia virus infection of mouse tumor cells might render them reactive with homologous mouse complement. Therefore, murine tumor cells, MH134 and X5563, infected with vaccinia virus (VV) were incubated with mouse plasma and C3 deposition was determined by staining with fluorescein isothiocyanate-labeled anti-C3. We found that VV-infected tumor cells possess the ability to activate the alternative complement pathway (ACP) of murine complement. For induction of complement activating ability, at least a 3 h incubation of the infected MH134 cells was required indicating that the generation of ACP-activating capacity on MH134 infected with VV is time-dependent. Furthermore, ultraviolet-irradiated vaccinia virus was able to induce ACP-activating capacity on tumor cells as well.

Animals↗
PubMed1989

Estrone sulfatase activity in normal and neoplastic endometrial tissues of human uterus.

Estrone sulfatase activity was measured in normal and neoplastic endometrial tissues of human uterus. The tissue homogenates were incubated in air with [3H] estrone sulfate (E1-S, 20 microM) at 37 degrees C for 30 min. After the enzyme reaction was terminated with ethyl ether, the ethyl ether extract was purified by thin-layer chromatography. The apparent Km of sulfatase was 3.0 microM, and the maximum velocity was 14.7 nmol/h/mg protein. Estrone sulfatase activity in endometrial tissues was detected throughout the menstrual cycle with no significant change. Moreover, estrone sulfatase activity in endometrial cells was not stimulated by the addition of progestogen. The enzyme activity in cancer tissue was significantly higher than in normal tissue. Thus we concluded that this enzyme may play a role in regulating the estrogen action by sifting the intracellular equilibrium between free estrogens and estrogen sulfates. We also concluded that in the endometrial cancer tissue, sulfatase appears to act on local production of estrone.

Endometrium↗
PubMed1989

Controlled release of LHRH agonist, leuprolide acetate, from microcapsules: serum drug level profiles and pharmacological effects in animals.

The pharmacokinetic behaviour of leuprolide acetate from a controlled release parenteral dosage form has been studied in rats and dogs. The release of the drug in rats after a single subcutaneous injection exhibited pseudo-zero-order kinetics for one month in doses ranging from 0.0135 to 1.35 mg/rat; the release rate at a dose of 1.35 mg/rat was 2.8% of dose/day; after intramuscular injection the response was similar. In rats, the serum leuprolide acetate levels increased sharply immediately after injection by either route as a consequence of the initial release of the drug; subsequently, the levels attained a plateau for two weeks. The serum level profiles in dogs showed essentially the same pattern as those in rats. When the dosage form was injected into rats, the serum testosterone level (a pharmacological index) sharply peaked, abruptly decreased to below the normal level, and then was sustained at a suppressed level for over six weeks at a dose of 1.35 mg/rat (equivalent to 3 mg kg-1) and higher, while the serum testosterone level after an injection of 0.0135 and 0.135 mg/rat was not sufficiently suppressed. The profiles in dogs showed essentially the same pattern as those in rats. With multiple administrations (once every 4 weeks), serum testosterone levels in dogs did not show any sharp rise after the second and third injections. Changes in rat reproductive organ weights agreed well with the serum testosterone profile in the suppression. The results demonstrate that this dosage form releases the drug at a constant rate for one month and has a long-acting potency.

Animals↗
PubMed1989

Plasmid dependence of Pseudomonas sp. strain NK87 enzymes that degrade 6-aminohexanoate-cyclic dimer.

A bacterial strain, Pseudomonas sp. strain NK87, that can use 6-aminohexanoate-cyclic dimer as the sole source of carbon and nitrogen was newly isolated from wastewater of a factory which produces nylon-6. Two responsible enzymes, 6-aminohexanoate-cyclic-dimer hydrolase (P-EI) and 6-aminohexanoate-dimer hydrolase (P-EII), were found in the NK87 strain, as is the case with Flavobacterium sp. strain KI72, another 6-aminohexanoate-cyclic-dimer-metabolizing bacterium (H. Okada, S. Negoro, H. Kimura, and S. Nakamura, Nature [London] 306:203-206, 1983). The P-EI enzyme is immunologically identical to the 6-aminohexanoate-cyclic-dimer hydrolase of KI72 (F-EI). However, antiserum against the 6-aminohexanoate-dimer hydrolase purified from KI72 (F-EII) did not react with cell extracts of NK87, indicating that the F-EII and P-EII enzymes are immunologically different. Restriction endonuclease analyses show that the NK87 strain harbors at least six plasmids ranging in size from 20 to 80 kilobase pairs (kbp). The P-EI and P-EII genes were cloned in Escherichia coli. Both the P-EI and F-EI probes strongly hybridized with a 23-kbp plasmid in Southern hybridization analyses. The P-EII probe hybridized specifically with an 80-kbp plasmid, but the F-EII probe hybridized with none of the plasmids harbored in NK87. These results indicate that the P-EI gene and P-EII gene are encoded on the 23-kbp and 80-kbp plasmids, respectively.

Amidohydrolases↗
PubMed1989

High homology between 6-aminohexanoate-cyclic-dimer hydrolases of Flavobacterium and Pseudomonas strains.

The nucleotide sequences of the genes for 6-aminohexanoate-cyclic-dimer hydrolases of Flavobacterium sp. strain K172 (F-nylA) and Pseudomonas sp. NK87 (P-nylA), enzymes essential for the degradation of a by-product of the nylon-6 industry, were obtained by the dideoxynucleotide chain-termination method. A 1,479-base-pair open reading frame starting at a GTG and terminating at a TGA was found for the both of the genes. The P-nylA and F-nylA genes encoded polypeptides of 493 amino acids and had only 10 base substitutions in the coding region, which caused seven amino acid substitutions.

Amidohydrolases↗
PubMed1989

Cloning, nucleotide sequence, and expression in Escherichia coli of the Bacillus stearothermophilus peroxidase gene (perA).

The gene encoding a thermostable peroxidase was cloned from the chromosomal DNA of Bacillus stearothermophilus IAM11001 in Escherichia coli. The nucleotide sequence of the 3.1-kilobase EcoRI fragment containing the peroxidase gene (perA) and its flanking region was determined. A 2,193-base-pair open reading frame encoding a peroxidase of 731 amino acid residues (Mr, 82,963) was observed. A Shine-Dalgarno sequence was found 9 base pairs upstream from the translational starting site. The deduced amino acid sequence coincides with those of the amino terminus and four peptides derived from the purified peroxidase of B. stearothermophilus IAM11001. E. coli harboring a recombinant plasmid containing perA produced a large amount of thermostable peroxidase which comigrated on polyacrylamide gel electrophoresis with the B. stearothermophilus peroxidase. The peroxidase of B. stearothermophilus showed 48% homology in the amino acid sequence to the catalase-peroxidase of E. coli.

Amino Acid Sequence↗
PubMed1989

[Mode of inhibitory action of propiverine hydrochloride on the micturition movements of the bladder in dogs].

Propiverine hydrochloride (P-4) is a new derivative of benzilic acid. The effect of P-4 on the vesico-detrusor reflex (corresponding to the first reflex of Barrington) in anesthetized or decerebrated dogs was studied to elucidate the mode of action of the drug. When bladder contraction was induced by electrical stimulation of the distal ending of the pelvic nerve under the bilateral pelvic nerve and hypogastric nerve transection, P-4 (2, 5 and 10 mg/kg, i.v.) significantly inhibited the contraction. A similar effect was also observed following intravenous administration of flavoxate (10 and 20 mg/kg), verapamil (1 mg/kg) or propantheline (2 mg/kg), while thiopental (4 mg/kg, i.v.) had no significant effect. When the bladder was filled under the bilateral pelvic nerve and hypogastric nerve transection, an increase of afferent impulses from the distal ending of a pelvic vesical branch was observed. P-4 (10 mg/kg, i.v.) had no effect on the afferent impulses. When the central endings of the pelvic vesical branches were electrically stimulated, reflex discharges were noted from a pelvic vesical branch on the contralateral side. Thiopental (2 and 4 mg/kg, i.v.) markedly decreased the reflex discharge, whereas P-4 (10 mg/kg, i.v.) caused no such inhibition. These findings suggest that the inhibition of the vesico-detrusor reflex by P-4 may result from its inhibitory action on the efferent terminal of the pelvic nerve.

Animals↗
PubMed1989

Estrogen biosynthesis in human uterine adenomyosis.

Estrogen biosynthesis (aromatase activity) was investigated in human adenomyosis tissue and compared with that of the normal myometrium, endometrium, and endometrial cancer tissues. Homogenates were incubated with [1,2,6,7-3H]androstenedione and NADPH at 37 degrees C for 1 h. After stopping the enzymatic reaction with ethyl acetate, [4-14C]estrone and [4-14C]estradiol-17 beta were added to the incubated sample. Estrone and estradiol were purified and identified by Bio-Rad AG1-X2 column chromatography, thin-layer chromatography and co-crystallization. Estrogen formed in the incubated sample was calculated from the 3H/14C ratio of the final crystal. The value for estrone formed from androstenedione was 52-132 fmol.h-1.g-1 wet weight. Aromatase activity in the adenomyosis tissues was higher than that in normal endometrial or myometrial tissues, but lower than that found in myometrial or endometrial tumour tissue. Furthermore, we investigated the effect of danazol, progesterone, and medroxyprogesterone acetate on adenomyosis cells in primary cultures. Aromatase activity in adenomyosis was blocked by danazol, but stimulated by progesterone and MPA. These results indicate that aromatase activity in adenomyosis may contribute to the growth of the ectopic endometrial tissue which occurs in this disease.

Adult↗
PubMed1989

[Polyclonal B cell activation induced by Actinomyces viscosus T14V. Responsiveness of human peripheral blood B cells].

We have previously reported that the sonicate extrast from Actinomyces viscosus T 14 V (Av. sup) causes polyclonal B cell activation (PBA) in murine splenic B cells without any T cell assistance. However, there are some reports describing T cell dependency of PBA induced by A. viscosus in human peripheral blood B cells, and it is still controversial whether or not A. viscosus has the capability of exhibiting PBA without the help of T cells. In this report, we examined PBA in human peripheral blood B cells using the same Av. sup which induced T cell independent PBA in murine splenic B cells. The PBA was evaluated in terms of immunoglobulin (Ig) production by means of micro-ELISA method and cell proliferation by incorporation of 3H-TdR after incubation of cells for 5 or 7 days with Av. sup. Human peripheral blood B cells were highly purified by the following methods; The peripheral blood was collected by venipuncture and the peripheral blood mononuclear cells were harvested using gradient centrifugations. These cells were passed through a Sephadex G-10 column, and T cells were eliminated by rosette formation with sheep red blood cells. B cells were highly purified from these T cell-depleted cell populations by panning method with anti-human Ig antibody coated dishes followed by complement-dependent cytotoxisity using monoclonal antibody cocktails consisting of OKT 3, OKT 4 and OKT 8. These highly purified B cells could not respond to T cell mitogens such as PHA.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomycetales↗
PubMed1989

[Application of synthetic hydroxyapatite to periodontal therapy].

The purpose of the present study was to evaluate the effectiveness of granular hydroxyapatite as an alloplastic bone implant material in infrabony periodontal defects. Thirty-five infrabony defects in 28 subjects with marginal periodontitis were used. The patients were instructed in oral hygiene and received several sessions of scaling and root planing. Granular hydroxyapatite was implanted into test sites with infrabony defects following application of internally beveled full thickness flaps, root planing, and defect debridement. Pocket depth and attachment level were recorded before and 3 and 6 months after surgery. Gingival recession, mobility of the tooth, plaque index, and gingival index were also recorded before and 1 and 2 weeks, and 1, 3 and 6 months after surgery. Redness and swelling of the gingiva and increase in tooth mobility appeared transiently after surgery, however, they disappeared in a short time. A significant reduction of mean pocket depth of 3.4 mm and a significant increase in the mean attachment level of 2.5 mm were observed at 6 months after surgery. The mean gingival recession during the experimental period was only 0.9 mm. The amount of hydroxyapatite remaining implanted in the infrabony defect was 73% 6 months after surgery. The data and clinical impression suggest that hydroxyapatite has a potential as an alloplastic implant with clinically apparent acceptance by soft and hard tissue.

Bone Resorption↗
PubMed1989

[Topical chemotherapy of chronic periodontitis using controlled-release insert containing ofloxacin (PT-01) without root planing].

Topical chemotherapy of periodontal disease using several drug delivery systems (DDS) is currently being attempted. PT-01 is a DDS which consists of fast- and sustained- release parts containing ofloxacin as an antibacterial agent. Since PT-01 was found to sustain the antibacterial effect for 7 days in a periodontal pocket, it was used tor periodontal patients without root planing or scaling in this study. PT-01 and a placebo were applied to two separate and opposite pockets of 46 patients, once a week from the first visit (week 0) to week 3. The clinical parameters (plaque index, gingival index, tooth mobility, bleeding on probing, pus discharge, and probing depth) were evaluated from weeks 0 to 4. At the end of the test (week 4), global improvement at the two sites was assessed. The clinical parameters and the global improvement of the PT-01 and placebo-treated sites were compared statistically. All parameters at the PT-01 sites except for tooth mobility showed much greater improvement than at the placebo sites. The global improvement of PT-01 sites was also significantly greater than that of the placebo sites. No side effects could be seen in patients treated with PT-01. These results indicate that topical chemotherapy using PT-01 could be effective and safe for periodontal therapy.

Chronic Disease↗