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Biomedical subjects

T Okabe

Publications and source records attributed to T Okabe.

At least 433 records · Page 24Linked to original sources
PubMed1984

Monoclonal antibodies to surface antigens of small cell carcinoma of the lung.

Monoclonal antibodies to membrane antigens of human small cell carcinoma of the lung were produced by fusion of P3X63/Ag8U1 mouse myeloma cells with spleen cells from BALB/c mice immunized against the intact cells of the small cell carcinomas grown in BALB/c nude mice. The hybrids were screened for antibody production using intact cells in a solid-phase radioimmunoassay or in a membrane fluorescence with a fluorescence-activated cell sorter. Four monoclonal antibodies were chosen that demonstrated reactivities with human small cell carcinoma of the lung and not with apparently normal diploid fibroblasts or lymphoblastoid cells. The antibodies designated as TFS-1 and TFS-2 rather demonstrated "pancarcinoma" reactivity, showing binding to the other types of lung cancer (adenocarcinoma, squamous cell carcinoma, and large cell carcinoma) and carcinomas derived from other organs, such as colon, pancreas, or stomach. The monoclonal antibodies TFS-3 and TFS-4 preferentially bound to small cell carcinoma cells and neuroblastoma cells, but not to non-small cell carcinomas (adenocarcinoma, squamous cell, or large cell). Especially, TFS-4 did not bind to a variety of other normal or malignant cells. Immunoprecipitation of the antigens by monoclonal antibodies and sodium dodecyl sulfate:polyacrylamide gel electrophoresis revealed that they had different molecular weights.

Animals↗
PubMed1984

[Fundamental and clinical evaluation on ceftriaxone in the pediatric field].

Fundamental and clinical evaluation on ceftriaxone (Ro 13-9904, CTRX) was performed. CTRX was compared with CEZ, CMZ, CTX and LMOX in the antibacterial activity against the clinical isolates such as S. aureus, E. coli, P. mirabilis, K. pneumoniae and S. marcescens. Against S. aureus, the MIC of CTRX ranged from 0.2 to greater than 100 micrograms/ml with a peak of 3.13 micrograms/ml, showing that CTRX was almost equal to CTX in activity, slightly superior to LMOX and much inferior to CMZ and CEZ, although some strains were not susceptible to CEZ. Against the intestinal strains of E. coli, K. pneumoniae and P. mirabilis, the MIC distribution of CTRX was similar to that of CTX and LMOX while CTRX showed the MIC as high as 3.13 micrograms/ml or above against 44% of all strains including the beta-lactamase producing strains of E. coli and K. pneumoniae, indicating a slight tendency of their becoming resistant. The MIC peaks against E. coli, K. pneumoniae and P. mirabilis were less than or equal to 0.1, 0.39 and less than or equal to 0.1 microgram/ml, respectively. As to S. marcescens which is drawing attention as a causative agent for infections inside of hospitals or those among young infants, CTRX inhibited 84% of the strains at 3.13 micrograms/ml, showing a definite superiority to CEZ and CMZ and a slight superiority to CTX and LMOX. The serum concentration after a single intravenous injection with 40 mg/kg reached a mean peak of 168.8 micrograms/ml at the first blood sampling (at 30 minutes) and gradually decreased to 137.5 micrograms/ml at 1 hour, 30.9 micrograms/ml at 6 hours, 12.6 micrograms/ml at 12 hours and 3.8 micrograms/ml at 24 hours, while the half-life time was 6.0 hours. The comparison of the serum level by 1 hour intravenous drip infusion between the dosage groups of 20 mg/kg and 40 mg/kg revealed that the former group reached a peak of 85.4 micrograms/ml at the termination of drip while the latter's peak was 176.6 micrograms/ml observed during the drip (30 minutes after the initiation of drip). The respective levels of the 2 groups were 15.4 and 32.1 micrograms/ml at 6 hours, 5.1 and 15.0 micrograms/ml at 12 hours, and 1.6 and 4.1 micrograms/ml at 24 hours, indicating a distinct dose-response 2 hours after the initiation of drip administration. The half-life times were 4.9 and 6.2 hours, respectively, which are the longest among the cephalosporins presently being developed.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗
PubMed1984

Long-term cultivation of a human colony-stimulating factor-producing cell line in a protein-free chemically defined medium.

To examine whether a human colony-stimulating factor (CSF)-producing cell line, T3M-1, can propagate and secrete CSF without protein supplements, long-term cultivation of the cells was carried out in a protein-free chemically defined medium. By the use of stepwise decreases in the fetal bovine serum concentration, continuous growth of T3M-1 cells has been established in a protein-free F-10 medium. The cells designated T3M-1-T2 have been propagated in this medium for 5 years. The population-doubling time of the cells is about 30 hr. Addition of serum stimulated the cell growth (population-doubling time, 17 hr) but did not increase the saturation density. The cells secreted large amounts of CSF (2000 colonies stimulated by 1 ml of the conditioned medium). Addition of serum to the culture increased CSF activity in the conditioned medium (3400 colonies/ml). The results showed that a human cancer cell line, T3M-1-T2, could be propagated in a protein-free chemically defined medium and secrete large amounts of CSF. The cells will serve as an excellent model for better understanding of the cell growth and production of CSF in the absence of any serum contamination.

Bone Marrow Cells↗
PubMed1983

Stimulation of human chorionic gonadotropin and progesterone secretion by tumor promoters, phorbol ester and teleocidin B, in cultured choriocarcinoma cells.

Both 12-O-tetradecanoyl-phorbol-1- acetate and teleocidin B stimulated the secretion of human chorionic gonadotropin by cultured choriocarcinoma cells. These tumor promoters also stimulated production of progesterone in the cells. However, the 2 tumor promoters did not exert a marked effect on the cellular binding of epidermal growth factor that also had a stimulatory effect on production of these hormones.

Alkaloids↗
PubMed1983

Establishment and characterization of a carcinoembryonic antigen (CEA)-producing cell line from a human carcinoma of the exocrine pancreas.

A human carcinoembryonic antigen (CEA)-producing cell line, T3M-4, has been established from explant cultures of a primary human pancreatic exocrine adenocarcinoma transplanted into nude mice. The tumor had metastasized in the patient. The tumor obtained from metastatic lymph nodes was the initial source for implantation in athymic nude mice. In the primary culture, host fibroblasts were eliminated by the use of the antiserum raised against nude mouse cells. T3M-4 cells have been continuously propagated in vitro during the past 26 months. The cells grew in a monolayered sheet with about 31 hours of population doubling time. The cells exhibited epithelial morphologic features resembling the structure of the original tumor, and they showed tumor takes when inoculated into athymic nude mice. Xenografts established from the cell line have retained a similar histology to the original tumor on serial transplantation. Chromosomal analysis revealed the cell line to be a human aneuploid one with a hyperdiploid mode. T3M-4 cells possess the characteristic function of CEA secretion in vitro in culture and in vivo in nude mice bearing the tumors produced by inoculation with the cultured cells. In view of these characteristics, T3M-4 cell line represents a new human pancreatic exocrine adenocarcinoma cell line that produces CEA.

Adenocarcinoma↗
PubMed1983

Cerebral vasomotor responsiveness during 100% oxygen inhalation in cerebral ischemia.

Cerebral vasoconstrictor responsiveness to 100% oxygen inhalation was measured in 149 subjects, including normal healthy volunteers and those with risk factors for cerebral arteriosclerosis (N = 87). Test results were compared among patients with hemispheric stroke and vertebrobasilar insufficiency (N = 62) with the 133Xe inhalation method. Normal volunteers without risk factors (N = 49), aged 25 to 86 years, showed symmetrical vasoconstriction. Asymptomatic subjects with risk factors (N = 38) and those with vertebrobasilar insufficiency (N = 25) had decreased hemispheric gray matter flow (Fg) values during rest, but vasoconstrictor responsiveness to 100% oxygen inhalation was not significantly reduced. In patients with acute hemispheric infarction, regional vasoconstrictor responsiveness to 100% oxygen inhalation was lost and/or paradoxically reversed; in patients with chronic hemispheric infarction, it was decreased. Testing vasomotor responses during hyperoxia is safe, clinically helpful, and demonstrates impaired vasomotor reactivity in infarcted regions.

Adult↗
PubMed1983

Cerebral vasomotor responses during oxygen inhalation. Results in normal aging and dementia.

Resting-state regional gray matter flow (Fg) values and cerebral vasoconstrictor responses induced by 100% oxygen inhalation were measured with the 133 Xe inhalation method in normal healthy volunteers aged between 15 and 86 years and in patients with senile dementia of Alzheimer's type (SDAT) or multi-infarct dementia (MID). Cross-sectional analysis revealed that there were linear decreases of oxygen responses with advancing age in 84 normal volunteers between the second to ninth decades. Eleven patients with SDAT showed bilateral and symmetrical reductions of resting-state Fg values compared with 22 age-matched normal healthy volunteers. Eight patients with MID showed no significant reduction of mean Fg values compared with normal controls and patients with SDAT. Oxygen vasoconstrictive responses in SDAT were symmetrical and similar to those seen in age-matched controls. Compared with patients with SDAT, patients with MID showed reduced oxygen vasoconstrictive responses that were asymmetrical between hemispheres as well as heterogeneous within hemispheres. Testing cerebral vasoconstrictor responses by 100% oxygen inhalation is helpful for differentiating SDAT from MID.

Aged↗
PubMed1983

Corrosion of the eta'(Cu-Sn) phase in dental amalgam.

Previous studies have shown preferential corrosion of the eta'(Cu-Sn) phase in high-copper dental amalgam both in vitro and in vivo, while samples of pure eta' have shown high corrosion resistance. To clarify this contradiction, samples of pure eta' crystals mixed with other phases were prepared and tested. Evaluation of the corrosion resistance was based on the results of coulometry at constant potential and potentiodynamic polarization. The corrosion susceptibility of eta' in the matrix of gamma 1(Ag-Hg) was considerably higher than the susceptibility of isolated eta'. The susceptibility of pure eta' also could be increased by plating it will small amounts of Hg. It was concluded that in dental amalgam, the presence of mercury in the phases surrounding eta' reduces its resistance to corrosion. Although eta' is more resistant to corrosion than gamma 2(Sn-Hg) which appears in low-copper amalgams, it is the least corrosion resistant major phase in high-copper amalgams and can suffer deterioration.

Copper↗
PubMed1983

Protective effects of antibody against intestinal invasion by Escherichia coli.

Seven Escherichia coli isolates from newborn calves with diarrhea were examined for enteropathogenic properties. One isolate penetrated into HeLa cells, four produced enterotoxin(s) and the remaining two possessed neither of these properties. Penetration of E. coli into HeLa cells was inhibited by antibody in bovine colostrum and in bovine and rabbit immune sera. The effective antibodies appeared to be mostly of the IgM class. The invasion by E. coli isolates was also examined by inoculation of the bacteria into the small intestine of E. coli-immunized and non-immunized guinea pigs. The isolate which penetrated into HeLa cells could penetrate the intestinal mucosa to be disseminated into various organs of non-immunized guinea pigs, but not of immunized guinea pigs, whereas no other isolates showed such pathogenicity in vivo. The inhibition of the invasion was observed when non-immunized guinea pigs were inoculated with the bacteria together with colostral or serum antibody. The results show the importance of antibody in the local defense mechanism against E. coli invasion.

Animals↗