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Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 829 records · Page 46Linked to original sources
PubMed1984

Serological characterization of Streptococcus mutans serotype polysaccharide g and its different molecular weight forms.

The serotype polysaccharide g from Streptococcus mutans 6715 was found to cross-react with serotype polysaccharide a from S. mutans HS6 and serotype polysaccharide d from S. mutans B13. Double immunodiffusion experiments indicated that the serotype polysaccharide g consisted of the following: (i) the type-specific g site; (ii) a cross-reactive site g-a that was in common with polysaccharide a; (iii) a cross-reactive site g-d that was in common with polysaccharide d; and (iv) a cross-reactive site g-(a-d) that was in common with both polysaccharides a and d. Moreover, by a procedure involving several column chromatography steps, six polysaccharide-containing fractions showing reactivity with anti-g serum were found. By gel filtration, the molecular weight estimates of fractions LI, LII, LIII, SI, SII, and SIII were 2 X 10(6), 5 X 10(5), 6 X 10(4), 3 X 10(4), 1.4 X 10(4), and 1 X 10(4), respectively. Double immunodiffusion analysis indicated that LI, LII, and LIII contained the four antigenic sites of the putative polysaccharide g. LII also contained another additional immunodominant region, designated site x. The analysis also suggested that fraction SI lacked the type-specific site g, fraction SII lacked sites g and g-a, and fraction SIII lacked sites g, g-a, and g-d.

Antigens, Bacterial↗
PubMed1984

Molecular weight dependence of permselectivity to rat small intestinal blood-lymph barrier for exogenous macromolecules absorbed from lumen.

The permselectivity to the small intestinal blood-lymph barrier for the exogenous macromolecules absorbed from the lumen was investigated using in situ rat closed loop experiment. We chose the fluorescein isothiocyanate-labelled dextran (FD) as macromolecule and lipid-surfactant mixed micelles as an absorption promoter. The mean molecular weights of FDs used were 10500, 17500, 39000 and 64200 (abbreviated: FD10 , 20, 40 and 70). The lymph/plasma ratios of FDs concentrations during 5 h post administration were 0.2-1.2 ( FD10 ), 0.4-1.3 ( FD20 ), 1.3-7.2 ( FD40 ) and 2.6-11.9 ( FD70 ), respectively. The FD40 and FD70 levels in the lymph were significantly higher than those in the plasma. The cumulative amounts (% of the absorbed quantity) of FDs in the lymph from the lumen of the small intestine for 5 h after administration were 0.46% ( FD10 ), 0.51% ( FD20 ), 1.17% ( FD40 ) and 1.89% ( FD70 ), respectively. These findings suggest that the threshold molecular weight of FD for the transfer into the lymphatics with higher level compared to the blood concentration from the lumen across the small intestinal blood-lymph barrier exists between 17500 and 39000.

Animals↗
PubMed1984

Intestinal absorption of carboxyfluorescein entrapped in liposomes in comparison with its administration with lipid-surfactant mixed micelles.

The absorption of carboxyfluorescein (CF) entrapped in liposomes from the small intestine was investigated in vivo using bile fistula rats. Within the intestine CF was not metabolized, but 32% of the entrapped CF was released for 3 h from the liposomes when incubated with luminal incubation solution. The data of CF disappearance from the intestinal lumen and of CF plasma concentration showed that no apparent difference was observed between administration of the liposomal CF and that of free dye. Especially in initial 60 min after administration of liposomal CF, the plasma concentration was obviously lower than that in free CF administration. On the contrary, the coadministration of 40 mM lipid-surfactant mixed micelles induced a remarkable promotive effect on the absorption of free CF already in the early periods of the initial 60 min. When liposomal CF was administered into the intestinal lumen of thoracic duct-cannulated rats, the concentration in lymph was lower than that in plasma. Intramural injection of liposomal CF into intestinal wall, however, showed a much higher concentration in lymph than that in plasma. These findings suggest that liposomal entrapment of CF has rather difficulty to be absorbed through the intestinal mucosa, while lipid-surfactant mixed micelles exert a remarkable promotive effect on the absorption of CF.

Animals↗
PubMed1984

A method to potentiate enteral absorption of interferon and selective delivery into lymphatics.

The potentiated absorption of human fibroblast interferon (HuIFN-beta) with the aid of lipid-surfactant mixed micelles from the rat large intestine and lymphatic delivery were studied. The administration of HuIFN-beta with saline solution alone into the lumen of the large intestine indicated no detectable HuIFN-beta in the serum or the lymph for 5 h. Neither lipid (linoleic acid) nor surfactant ( HCO60 , polyoxyethylene hardened castor oil derivative) could promote the absorption of HuIFN-beta. However, the administration with linoleic acid- HCO60 mixed micelles enabled the great absorption of HuIFN-beta from the large intestine, and HuIFN-beta was delivered into the lymphatics with an extremely high selectivity.

Animals↗
PubMed1984

Enhancing effect of absorption promoters on percutaneous absorption of a model dye (6-carboxyfluorescein) as poorly absorbable drugs. I. Comparison of plasma levels after addition of various absorption promoters in rat.

We have investigated the promotive effect of various agents on percutaneous absorption of 6-carboxyfluorescein (CF), a water-soluble fluorescent dye, as poorly absorbable drugs. The absorption of CF was determined by measuring rat plasma CF levels. As an absorption promoter, several reagents such as surface-active agents, protein solubilizers and permeation promoters were used. The used concentration of the reagents was determined so as not to make a trauma on the skin. As results, plasma CF levels following the co-administration of 0.05 w/v% sodium dodecyl sulfate and 0.1 v/v% 2-mercaptoethanol showed the highest values. Plasma CF level was increased 40 times as compared to that of control experiment and was increased 9 times as compared to that of pretreatment with 4 w/v% calcium thioglycolate which was reported previously as a strong absorption promoter for theophylline by us. When the stratum corneum, having a barrier function for percutaneous absorption of many compounds, was removed mechanically, plasma CF levels of control experiment and pretreatment with 4 w/v% calcium thioglycolate were increased remarkably. However, plasma CF level after the co-administration of 0.05 w/v% sodium dodecyl sulfate and 0.1 v/v% 2-mercaptoethanol did not show a considerable difference as compared to that of the case with the presence of the stratum corneum.

Administration, Topical↗
PubMed1984

Effect of oxygen concentration on pulmonary fibrosis caused by peplomycin in mice.

The pulmonary fibrosis caused by peplomycin (PEP) was studied in terms of oxygen toxicity using ICR mice. When 16 micrograms of PEP was administered intratracheally in mice after exposure to the air containing 75% O2 for 10 days, the pulmonary fibrosis was completely suppressed, while when mice were exposed to 75% O2 after the administration of PEP, the fibrosis was much severe than that of mice raised in atmospheric air. In 50% O2, similar oxygen effect was also observed, but it was weaker than that in 75% O2. In 90% O2, the oxygen toxicity was observed in mice without administration of PEP. When mice were exposed to 75% O2, the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, which are relevant to the detoxication of active oxygen species, were not increased in the lung, but the levels of reducing agents such as glutathione and ascorbic acid, and high molecular substances having 1O2-scavenging activity were enhanced. The results suggest that these materials have some roles to decrease the pulmonary fibrosis caused by PEP.

Animals↗
PubMed1984

Intraarterial infusion of 4'-O-tetrahydropyranyl-adriamycin for head and neck tumors.

THP-adriamycin was administered in a dose of 5 to 20 mg, 3 times a week, and the results showed 4 cases of CR, 5 cases of PR, 3 cases of MR and 2 cases of NC with the accumulated total dose of less than 100 mg. Histological effects were slight in a total dose of less than 50 mg, while the effects appeared in a total dose of 60 to 70 mg and further effects were obtained after about 1 week of the termination of the therapy. Leukopenia occurred in 6 of 14 cases. The side effects of THP-adriamycin were milder than those of ADM.

Aged↗
PubMed1984

[Retrovesical sarcoma (rhabdomyosarcoma): report of a case and a review of 46 cases in Japan].

The patient was a 2-year-old boy, who was brought to our clinic with the chief symptom of urinary retention. We suspected retrovesical tumor by digital examination, intravenous pyelography and retrograde cystography. Surgery was performed and the bladder and prostate including the tumor were removed. Ureterocutaneostomy was constructed on both sides. The pathohistological diagnosis was rhabdomyosarcoma (embryonal type). Thereafter, chemotherapy and irradiation were applied, but the patient died of cachexia which was clinically caused by a local recurrence, fourteen months after the operation. Forty-six cases of retrovesical sarcoma were collected from the recent Japanese literature, and reviewed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Multiplicity-dependent induction of viral capsid antigen in Raji cells superinfected with Epstein-Barr virus.

A quantitative analysis of Epstein-Barr virus (EBV)-induced early antigen (EA) and viral capsid antigen (VCA) syntheses was carried out in Raji cells superinfected with purified, concentrated P3HR-1 EBV. When the cells were exposed to the virus and assessed by immunofluorescence and immunoprecipitation, EA induction occurred significantly (17%) but not VCA (less than 1%), at a low-input multiplicity of infection (MOI) of 10 EBV DNA copies/cell. In contrast, at a high MOI of 500 EBV DNA copies/cell, the majority of cells were positive for both EA (82%) and VCA (61%). The latter VCA synthesis was accompanied by the replication of EBV DNA. Kinetic studies showed that EA induction was directly proportional to the dilution of the infecting virus, while VCA was made following three-hit kinetics. The implications of these results are discussed in relation to the heterogeneous nature of P3HR-1 EBV and a possible role of EA in VCA synthesis.

Antigens, Viral↗
PubMed1983

Pharmacokinetics of bredinin in renal transplant patients.

A pharmacokinetic study of bredinin, a new immunosuppressive agent, was carried out in 28 renal transplant patients. Serum bredinin concentration-time curves were analyzed using a one-compartment open model with a first order absorption process. The peak serum bredinin level appeared 2.4 h after oral administration of bredinin 50-200 mg. The calculated mean peak serum level was 0.852 micrograms/ml/mg/kg, when the dose was adjusted to the body weight of the patient. In the dosage range used of 0.85-4.46 mg/kg, a linear relationship was observed between the dose and the peak serum bredinin level. The elimination rate of bredinin from serum was dependent on kidney function, and the elimination rate constant was well correlated with the endogenous creatinine clearance. No circadian rhythm was apparent in the elimination rate constant. The absorption rate of bredinin from the gastrointestinal (GI) tract was affected by GI diseases. The need for dosage adjustment based on the renal function of the transplant patient is suggested.

Adolescent↗
PubMed1983

Monoclonal antibody specific for capsid antigen of Epstein-Barr virus.

A hybrid cell line (Cl-51) producing an anti-capsid antibody was obtained by fusion of mouse myeloma cells with spleen cells from mice immunized with purified P3HR-1 Epstein-Barr virus (EBV). Immunofluorescence showed that the Cl-51 antibody reacted with the cytoplasm and the nucleus of P3HR-1 and B95-8 cells, but not with Raji, BJAB, Molt-4, and superinfected Raji cells in the presence of cytosine arabinoside (Ara-C). The viable P3HR-1 and B95-8 cells were not stained nor was the viral infectivity neutralized. The Cl-51 antibody immunoprecipitated 123,000 and 120,000 dalton polypeptides of P3HR-1 and B95-8 cells, respectively, and both were sensitive to phosphonoacetic acid. Specific reactions were not evident with extracts of Raji cells and superinfected Raji cells in the presence of Ara-C. An analysis of the purified virus particles showed that this antibody recognized a capsid component of EBV.

Animals↗
PubMed1983

Operational performance of the Reflex Metrograph and its applicability to the three-dimensional analysis of dental casts.

The purpose of the present study was to investigate the applicability of a new instrument (the Reflex Metrograph) to the three-dimensional analysis of dental casts. In this system, a dental cast, placed in front of a semireflecting mirror, creates an identical image behind the mirror. The measurement of a point is made by aligning a light source behind the mirror in coincidence with the image of a specific point on the object. The light source is carried on a three-dimensional slide system, and coordinates are digitized for sampling by the computer. Measurement accuracy of the instrument was evaluated for three measuring points determined on a maxillary dental cast placed in six different locations. In addition, differences in the performance skills of ten operators were evaluated. The results indicate that digitization of a point in three planes of space can be undertaken without direct contact of the object and that a consistent measurement accuracy can be obtained, regardless of differences in the location of the cast relative to the mirror or in the anatomic shape of the measured areas. In addition, operators with no previous experience can determine specific points to an accuracy of +/- 0.1 mm, with a minimal amount of training. Finally, measurement by the same operator for a pooled sample is recommended in order to avoid interoperator measurement error when determining linear distances.

Computers↗