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Biomedical subjects

T Okuda

Publications and source records attributed to T Okuda.

At least 271 records · Page 15Linked to original sources
PubMed1992

PCTAIRE-1 and PCTAIRE-3, two members of a novel cdc2/CDC28-related protein kinase gene family.

We have isolated two murine cDNAs designated PCTAIRE-1 and -3 which encode putative serine/threonine-specific protein kinases. The predicted products of PCTAIRE-1 and -3 are 65% homologous and are organized into a core 295-residue kinase domain flanked by unique 161 and 117 amino acid N-terminal and 40 and 39 amino acid C-terminal domains respectively. The kinase domains are approximately 50-55% homologous to members of the cdc2/CDC28 kinase gene family, and each contains a cysteine-for-serine substitution within the conserved PSTAIRE motif. PCTAIRE-1 was ubiquitously expressed as a predominant 3.0-kb transcript and a minor 2.2-kb mRNA resulting from differential polyadenylation. In contrast, PCTAIRE-3 exhibited a more restricted pattern of expression with a single 3.0-kb mRNA detected in brain, kidney and intestine. The PCTAIRE-1 and -3 products produced by in vitro transcription-translation failed to bind to p13suc1 but were precipitated by antibodies directed to Schizosaccharomyces pombe p34cdc2 or to the human PSTAIRE motif. Thus, PCTAIRE-1 and -3 are members of a novel subfamily of cdc2/CDC28-related protein kinases.

Amino Acid Sequence↗
PubMed1992

[Effective high frequency jet ventilation setting for the preparation of internal thoracic artery for coronary artery bypass graft surgery].

Effective high frequency jet ventilation (HFJV) setting during the preparation of internal thoracic artery (ITA) was estimated in 35 patients who underwent coronary artery bypass graft (CABG) surgery. During ITA preparation, ventilation with the minimum lung movement without circulatory deterioration is necessary. Therefore, appropriate frequency, inspiratory time interval (Ti%) and working pressure (WP) for HFJV were investigated. Rising WP and prolonged Ti% provoked increasing tidal volume and decreasing PaCO2, whereas the lung extension disturbed the ITA preparation. By modifying the settings of frequency, Ti% and WP, we determined the frequency of 3Hz and Ti% of 50%. The correlation between WP at normocapnia and bodyweight (BW) is expressed in the following formula: WP = 0.16 x BW - 0.0003 (r = 0.72) Moreover satisfactory recording of end-tidal CO2 could not be obtained during HFJV. Therefore, we used transcutaneous CO2 (tc-CO2) analyzer. The coefficient between tc-CO2 and PaCO2 was 0.95, and tc-CO2 was useful as a non-invasive monitoring of PaCO2. There was little change in blood pressure, heart rate and cardiac output during HFJV. However mean pulmonary artery pressure (mPAP) increased significantly during hypercapnia especially when PaCO2 was over 50 mmHg. This suggests that mPAP may be more sensitive to PaCO2 compared with other circulatory parameters. HFJV with these settings produced good outcome for ventilation and circulation during the preparation of ITA.

Adolescent↗
PubMed1992

[The clinical effect of cisplatin and 5-FU infusion in oral cancer].

The combination chemotherapy of cisplatin and 5-fluorouracil (5-FU) is more effective than monotherapy of either drug in the head and neck cancer. In 1982, Kish reported that CF-therapy, the combination of cisplatin and 5-FU, had a high curative rate (about 82%). CF-therapy was utilized in 9 patients with carcinoma of the oral region from March, 1987 to September, 1990 in our hospital. The patients' ages ranged from 23 to 74 years old with an average of 55. All tumor were squamous cell carcinoma. There were 2 cases in stage II, 4 cases in stage III and 3 cases in stage IV. Two patients treated with only CF-therapy and the other patients treated with radiotherapy and operation in addition to CF-therapy. Our regimen is cisplatin 80-100 mg i.v. or i.a. in day 1 and 5-FU 250 mg i.a. or 5-FU 750 mg i.v. in day 2-6. The therapeutic results showed a 78% response rate to the therapy with 4 cases of CR (complete response), 3 cases of PR (partial response), 1 case of MR (minor response) and 1 case of PD (progressive disease). Side effects of cisplatin plus 5-FU (eg. nausea and vomiting) were so severe that the treatment had to the stopped in many patients. The method we have reported here was evaluated, and it is concluded that this CF-therapy is very effective as a first treatment of oral cancer.

Adult↗
PubMed1991

Determination of atropine in biological specimens by high-performance liquid chromatography.

A sensitive and selective method for the determination of atropine in biological specimens has been developed. Samples alkalinized with sodium hydroxide were extracted with dichloromethane, and the organic phase was evaporated in a water-bath at 50 degrees C for ca. 10 min. The residue was dissolved in the mobile phase and injected into a reversed-phase column (TSK gel ODS-120A). The retention time for atropine could be varied by changing either the acetonitrile-water ratio in the mobile phase or the pH of the mobile phase. Acetonitrile-water (2:8, v/v) containing 6 mM phosphoric acid was used as mobile phase. Samples of 200 microliters or less were injected into the chromatography and measured at 215 nm. The recoveries of atropine added to drug-free specimens were satisfactory with coefficients of variation of 4% or less. Ninety-two compounds tested did not interfere with the assay of atropine. The method has been applied for monitoring atropine concentrations in cases of organophosphate and drug poisoning.

Adult↗
PubMed1991

Hemophagocytic syndrome associated with aggressive natural killer cell leukemia.

We describe a patient who had aggressive natural killer cell leukemia with profound hemophagocytosis. This combination must be underscored as one of several hemophagocytic syndromes. Activated phagocytes in the bone marrow appeared morphologically normal and could possibly be proliferating in response to some cytokine(s) such as interferon-gamma produced by leukemic cells, whose serum level was found to be extremely elevated in this case.

Adult↗
PubMed1991

Serum CEA levels in patients with gastric carcinoma correlate with the tumorigenicity of their xenografts in nude mice.

We examined the correlation among preoperative serum carcinoembryonic antigen (CEA) levels, staining properties of the tumors by CEA immunohistochemistry and the tumorigenicity of their xenografts in nude mice, in 28 patients with gastric cancer. Eleven (40 per cent) of them were positive for serum CEA (greater than or equal to 2.5 ng/ml) and seven (25 per cent) of the xenografts were tumorigenic in nude mice. All the tumorigenic cases were positive for serum CEA (p less than 0.001) and the mean value of the serum CEA level in the patients with tumorigenic neoplasms was 20.8 ng/ml, being significantly higher than that (1.4 ng/ml) in the patients with non-tumorigenic neoplasms (p less than 0.001). Twenty-five of the 28 carcinomas (89 per cent) were positive for CEA staining in their cancer cells by the ABC method and CEA localization correlated with tumorigenicity (p less than 0.05). These results suggest that the serum CEA level in patients is correlated with the tumorigenicity of their gastric carcinoma xenografts in nude mice and may account for the poor prognosis of patients with high serum CEA.

Adolescent↗
PubMed1991

Dephosphorylation of specific proteins in HL-60 cells by 1 alpha, 25-dihydroxyvitamin D3: possible involvement of cAMP-dependent protein kinase.

Changes of phosphoprotein patterns in HL-60 cells were studied during short exposures to 1 alpha, 25-dihydroxyvitamin D3 [1,25(OH)2D3]. One hundred nanometers 1,25(OH)2D3 dephosphorylated at least three proteins in 6 h: phosphoproteins with molecular weights of 82 kD (pp82), 33 kD (pp33), and 31 kD (pp31). Phosphorylation of pp33 and pp31 was also suppressed by 1 mM dbcAMP, and dephosphorylation of the two protein by 1,25(OH)2D3 was inhibited by 8 microM H-8, an inhibitor of cAMP-dependent protein kinase (PKA). Furthermore, 8 microM H-8 inhibited dephosphorylation of the two proteins when it was added with 1,25(OH)2D3. On the other hand, 10 nM TPA gave no significant change to these two phosphoproteins. These results suggest the possibility that PKA is involved in the early stages of 1,25(OH)2D3-induced HL-60 cell differentiation through specific protein dephosphorylation.

Bucladesine↗
PubMed1991

Experimental vaccine protection against feline immunodeficiency virus.

Infection of domestic cats with the feline immunodeficiency virus (FIV) represents an important veterinary health problem and a useful animal model for the development of vaccines against acquired immunodeficiency syndrome (AIDS). Two experimental FIV vaccines have been developed; one consisting of fixed infected cells (Vaccine 1), the other of inactivated whole virus (Vaccine 2). After 4-6 immunizations over 2-5 months, both vaccines induced a strong FIV-specific immune response including neutralizing antibody and T-cell proliferation. Vaccine 1 protected 6 of 9 and Vaccine 2 protected 5 of 6 recipient cats against any detectable infection with a low dose (10 animal ID50) of FIV given intraperitoneally 2 weeks after the final boost. One additional cat in each vaccine group had a transient infection at 5-7 weeks postchallenge following which virus could no longer be detected. Thus, a total of 13 of 15 vaccinated cats were protected against persistent infection. By contrast, 13 of 13 controls were persistently infected by this challenge. The infected cell vaccine failed to protect against a higher dose (5 x 10(4) ID50) of FIV. These results indicate that vaccine prophylaxis against natural FIV infection should be achievable and enhance optimism of the prospect of developing an effective AIDS vaccine for humans.

Animals↗
PubMed1991

Production and characterization of human monoclonal antibody recognizing the N-terminal residues of Pseudomonas aeruginosa exotoxin A.

Human cell lines producing monoclonal antibodies (MAbs) against Pseudomonas aeruginosa exotoxin A were established by EBV transformation followed by cell fusion. Monoclonal antibody FK-001, IgM (mu, kappa), was demonstrated to be specifically reactive with exotoxin A in ELISA and immunoblotting, by recognizing N-terminal 16 amino acid residues of exotoxin A as an epitope. This epitope region belongs to domain I which is required for the binding of exotoxin A to the receptor on target cells. FK-001 showed a partial neutralizing activity for cell toxicity caused by exotoxin A and appeared to be effective against exotoxin A-producing P. aeruginosa infection in mice. A line of evidence suggests that monoclonal antibody FK-001 neutralizes exotoxin A-induced cell toxicity by the interference of accessibility and/or binding of exotoxin A to animal cell receptors.

ADP Ribose Transferases↗
PubMed1991

Murine polymorphonuclear leukocytes synthesize and secrete the third component and factor B of complement.

Complement proteins in serum are synthesized mostly by hepatocytes and many other cell-types have also been shown to synthesize complement in various tissues. However, polymorphonuclear leukocytes (PMNs) have never been reported to secrete complement. This paper demonstrates the synthesis and secretion of C3 and factor B by murine peritoneal exudate PMNs elicited with OK432 (Streptococcus preparation). Using [35S]methionine incorporation and immunoprecipitation, C3 and factor B produced by PMN are found to be antigenically and physically identical to macrophage C3 and factor B. ELISA analysis reveals that culture supernatant of PMN--free of macrophage contamination--contains C3 antigen, and both flow cytometric analysis and immunoperoxidase staining also demonstrate the presence of intracellular C3 using special precautions to eliminate non-specific staining. The role of complement produced by PMN is currently unknown, but it is very important to take this new finding into consideration for further clarification of the roles of complement in extravascular inflammatory sites.

Animals↗
PubMed1991

Abrupt increase in the level of hydrogen peroxide in leaves of winter wheat is caused by cold treatment.

After cold treatment of seedlings of winter wheat (Triticum aestivum L.), levels of hydrogen peroxide in the leaves were measured. The concentration of hydrogen peroxide increased to about three times the control level within a few minutes, and returned to the normal level in 15 to 20 minutes. The elevated level of hydrogen peroxide was found to be equivalent to 1.5 micromoles per gram fresh weight tissues of leaves.

Journal Article↗
PubMed1991

A protective human monoclonal antibody directed to the outer core region of Pseudomonas aeruginosa lipopolysaccharide.

The protective activity against experimental Pseudomonas aeruginosa infection of a human monoclonal antibody, MH-4H7, which is thought to recognize L-rhamnose and its neighboring residues in the outer core region of P. aeruginosa lipopolysaccharide and which binds to strains of Homma serotypes A, F, G, H, K, and M, was studied in normal, burned, and leukopenic mice. MH-4H7 at doses of 0.1 to 1.0 micrograms per mouse (5 to 50 micrograms/kg) was effective against serotype A, F, G, H, and K clinical isolates of P. aeruginosa tested in normal mice but not against strains of serotype M, B, E, or I. The 50% protective doses were calculated to be 0.01 and 0.1 micrograms per mouse against challenge with serotype G strains and 3 to 8 micrograms per mouse against challenge with serotype A strains. MH-4H7 promoted macrophage-mediated opsonophagocytosis of serotype A, F, G, H, and K strains but not of serotype M strains. The opsonophagocytic activity, expressed as the reduction rate of viable bacteria in the presence of MH-4H7, macrophages, and complement, was higher against serotype G strains (more than 90%) than against serotype A strains (60 to 80%) and serotype F, H, and K strains (50 to 86%). It was correlated with the protective activity but not with the binding intensity of MH-4H7 to the organisms. In addition, burned and leukopenic mice as well as normal mice infected with serotype G strains recovered from a very low dosage of MH-4H7. Thus, a monoclonal antibody directed to the outer core region of P. aeruginosa lipopolysaccharide was effective against infection with a wide range of O-serotype strains of P. aeruginosa.

Animals↗
PubMed1991

Ion channel activities of cultured rat mesangial cells.

We used the patch-clamp technique to clarify the nature of ion channels in renal mesangial cells in culture. In the cell-attached mode most patches were silent in the absence of agonists. In some patches a 25-pS nonselective channel was observed. This 25-pS cation channel was consistently observed in inside-out patches, and it was activated by intracellular Ca2+. Excised patch experiments also revealed the existence of a 40-pS K+ channel, which was activated by intracellular Ca2+. This 40-pS K+ channel was observed infrequently in the cell-attached mode. The activities of both channels were increased by arginine vasopressin or angiotensin II, resulting from an increase in intracellular Ca2+ concentration.

Angiotensin II↗
PubMed1991

Development of IL-2-independent feline lymphoid cell lines chronically infected with feline immunodeficiency virus: importance for diagnostic reagents and vaccines.

Two interleukin 2 (IL-2)-independent feline immunodeficiency virus (FIV) producer cell lines (FL-4 and FL-6) were produced by selecting cells from an IL-2-dependent culture of mixed peripheral blood lymphocytes infected with FIV. The new cell lines have been stable for over 1 year and spontaneously produce FIV with an average reverse transcriptase titer of 300,000 cpm/ml and an average sucrose gradient purified viral protein concentration of 1 mg/l. FIV produced from these cultures is highly infectious in vitro and in vivo. The FL-6 cell line was phenotyped as expressing the feline CD8 and Pan-T antigens, while the FL-4 cell line expressed the CD4, CD8, and Pan-T antigens. Both cell lines, however, express high levels of viral core and envelope proteins. Paraformaldehyde-inactivated whole virus and similarly inactivated whole-cell virus preparations induced a strong antibody response to core and envelope antigens in immunized cats. The establishment of FIV-producing feline IL-2-independent peripheral blood lymphocyte lines should be valuable for the development of FIV-diagnostic reagents and vaccines and also as a model for human acquired immunodeficiency syndrome vaccine development.

Animals↗
PubMed1991

Effects of geraniin on morphology and function of macrophages.

The effects of geraniin, a tannin, isolated from Geranium thunbergii Sieb. et Zucc. on the morphology and function of macrophages were studied. Geraniin caused a marked retardation of the recovery from fully spread surface membrane and a highly reorganized cytoskeleton of macrophages, whereas endocytotic activity, phagocytosis and pinocytosis in the cells were significantly inhibited.

Actin Cytoskeleton↗