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Biomedical subjects

A Furuya

Publications and source records attributed to A Furuya.

At least 55 records · Page 3Linked to original sources
PubMed1990

Perforin, a pore-forming protein detectable by monoclonal antibodies, is a functional marker for killer cells.

Perforin is one of the important cytolytic factors in cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. In this paper, we report rat mAbs against mouse perforin established by immunization with a recombinant mouse perforin fragment. These mAbs reacted with purified mouse perforin prepared from cytoplasmic granules of an NK-like cell line in ELISA and Western blot analysis. However, none of these mAbs blocked the hemolytic activity of mouse perforin or absorbed it when fixed in the solid phase. These results indicate that all of these mAbs react with denatured but not with native mouse perforin. By using a combination of the mAbs, we established a sandwich ELISA, for quantitating the cellular contents of perforin. These mAbs were also useful for immunohistochemical staining analysis, and perforin was detected in the cytoplasmic granules of CTL and NK cell lines. Perforin was also detected in a minor population of lymphocytes of the spleen, liver, and lymph node. In normal spleen cells of 5- to 8-week-old mice, 12-15% of asialo GM1+ cells and 7-21% of CD8+ T cells were perforin-positive, but CD4+ T cells, B cells, and macrophages were totally negative. These data clearly show that perforin is expressed in cells of a cytotoxic character in normal mice, in the same way as in primed mice.

Animals↗
PubMed1990

Indomethacin sustained-release suppositories containing sugar ester.

We prepared indomethacin (IM) sustained-release suppositories using sugar ester (SE) as an additive. The suppositories were prepared by the fusion method with IM, SE, and Witepsol H-15 (H-15) and their availabilities in vitro and in vivo were evaluated mainly by the drug release test and the absorption test in rabbits, respectively. The softening point of the suppositories increased with increasing SE content. In the release test with the Muranishi method, slow-release profiles were obtained when the SE content was more than 52.5%. The absorption of IM from these suppositories, however, was very little. In the other release test, e.g. immersion method with gauze, all of the suppositories with SE showed slow-release profiles, and the drug release rates clearly depended on the SE content. The drug was released from the suppositories by the following leaching-type mechanism proposed by Higuchi. The suppository with a 30% SE content showed a sustained-plasma level of IM, but the other suppositories did not. It was concluded that an appropriate content of SE (i.e. 30%) in the suppository base was required to obtain sustained-release because it reasonably regulated the infiltration of rectal fluid into the suppository and the mechanical strength of the suppository against disintegration.

Animals↗
PubMed1990

Indomethacin sustained-release suppositories containing sugar ester in polyethylene glycol base.

Indomethacin (IM) sustained-release suppositories were prepared by the fusion method using sugar ester and polyethylene glycol 4000 (PEG). The suppositories were evaluated by in vitro release testing, X-ray analysis and in vivo absorption testing in rabbits. X-ray analysis showed that IM was amorphous in PEG-base suppositories. In a release test, slow-release was obtained when the sugar ester content of a suppository was 60%. The IM plasma level following the administration of the suppository was well sustained in the absorption test. The main slow-release mechanism is considered to be the release of IM from the matrix composed of sugar ester and PEG, which is represented by the Higuchi equation. A good correlation between the release test and the absorption test was obtained. It is considered that the amorphous state of IM in this type of sustained-release suppository would enhance the release and absorption of IM in the rectum of the rabbit, whose rectal fluid volume is small.

Animals↗
PubMed1989

Study on absorption of indomethacin from sustained-release suppositories containing hydrogenated soybean lecithin in rabbits.

The absorption of indomethacin (IM) from suppositories containing hydrogenated soybean lecithin (HL) after rectal administration in rabbits was investigated with the aim of producing sustained-release suppositories. The suppositories were prepared by the fusion method with IM, HL and Witepsol H-15 (H-15). The IM release rate from the suppositories (IM 10 mg, HL 200 mg, total weight 1 g) was faster than that of the control suppositories without HL. The release of IM from the suppositories (IM 10 mg, HL 300 mg or 350 mg) showed slow-release profiles. In absorption studies in rabbits, sustained-plasma levels of IM were obtained when suppositories having an HL content of more than 300 mg were administered. The suppositories composed of Witepsol E-85 (melting point approximately 43 degrees C), 10 mg of IM, and 200 mg of HL, showed slow-release profiles in the release test, but did not show sustained plasma levels of IM in the absorption test. These results indicate that sustained-release suppositories able to release IM gradually from the surface of the suppositories can be obtained when HL, IM and H-15, whose melting point is lower than body temperature, are used in the preparation of the suppositories, provided that the HL content is high enough in relation to IM.

Animals↗
PubMed1987

Effect of phenothiazines, disodium ethylenediaminetetraacetic acid and diethyl maleate on in vitro rat colonic transport of cefmetazole and inulin.

An in vitro rat colonic sac method developed in this study was found to be suitable for frequent collection of samples and determination of transport of compounds from serosal and mucosal medium, since the volume of both was large. Under no a treatment condition, both cefmetazole and inulin penetrated the intestinal mucosa via the paracellular route, but did so very poorly. Phenothiazines as well as disodium ethylenediaminetetraacetic acid increased the transport of cefmetazole and inulin, probably via the paracellular route, while diethyl maleate increased the transport of only cefmetazole, probably via the intracellular route. The effect of phenothiazines in increasing the clearance rate for both cefmetazole and inulin showed dependency on their initial concentrations in the mucosal medium with maximum action at a concentration of 30 microM for trifluoperazine, 20 microM for perphenazine, 75 microM for profenemine and 50 microM for propericiazine.

Animals↗
PubMed1986

Primary cultures of human myasthenia gravis thymus and normal thymus. Studies of cell morphology, cell proliferative pattern and localization of alpha-bungarotoxin binding sites on cultured thymic cells.

We have established primary cultures of human myasthenia gravis (MG) thymuses and normal thymuses. In cultures of 19 thymuses with hyperplasia among 23 MG thymuses and 12 thymuses among 13 normal thymuses, epithelial cells migrated in a mosaic-like arrangement and were maintained for more than 5-10 weeks. There were, among mononuclear epithelial cells, some multinucleated cells, some of which were considered to be derived from epithelial cells because they had a desmosome-like structure and contained tonofilaments in their cytoplasm. There was no significant difference in the morphology of epithelial cells between MG thymuses and normal thymuses. The growth rate of thymic epithelial cells was identified by [3H]thymidine autoradiography(ARG), labeling indices rising to a peak around a week and falling to low levels gradually. There was no significant difference in the growth rate of epithelial cells between MG thymuses and normal thymuses. An autoradiographic method with 125I-labeled alpha-bungarotoxin was used to detect the presence of acetylcholine receptor (AChR) on the cultured cells. ARG of human MG thymuses and normal thymuses, which were cultured for 4 weeks, revealed diffusely distributed silver grains on the epithelial cells. Toxin binding sites (AChRs) were considered to be present on the epithelial cells. There was no significant difference in the distribution of AChR on the epithelial cells between MG thymuses and normal thymuses.

Adolescent↗
PubMed1986

Effects of phenothiazines and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide on rat colonic absorption of cefmetazole.

Rat colonic absorption of cefmetazole was increased significantly by calmodulin inhibitors such as phenothiazines and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) when they were coadministered at a concentration between 1 and 100 microM. The bioavailability of cefmetazole, determined by area under the blood concentration curve method, increased 20 to 30% by the coadministration of calmodulin inhibitors. It is speculated that the enhancing action of agents on rat colonic absorption of cefmetazole takes place by a paracellular route and coadministration of sodium ion increases their actions.

Animals↗
PubMed1984

Functional expression of the genes of Escherichia coli in gram-positive Corynebacterium glutamicum.

Hybrid plasmids were constructed by combining in vitro the Escherichia coli plasmid pGA22, which carries the genes determining resistance to kanamycin, tetracycline, chloramphenicol and ampicillin, with the cryptic plasmids, pCG1 and pCG2, of Corynebacterium glutamicum. The hybrid plasmids were introduced into C. glutamicum and E. coli and replicated in both hosts. They expressed all the E. coli resistance phenotypes except ampicillin resistance in C. glutamicum. The levels of antibiotic inactivating enzymes encoded on these plasmids were about four to ten times lower in C. glutamicum than in E. coli. Despite the lack of expression of ampicillin resistance, beta-lactamase activity was detected in C. glutamicum carrying hybrid plasmids.

Corynebacterium↗
PubMed1984

Efficient expression in Escherichia coli of a mature and a modified human interferon-beta 1.

Ten recombinant plasmids were constructed which direct the synthesis of a mature human interferon-beta 1 (IFN-beta 1) under the control of the Escherichia coli tryptophan (trp) promoter. The spacing between the Shine-Dalgarno sequence of the trpL and the ATG initiation codon of the interferon gene was varied from 6 to 23 nucleotides by utilizing a Cla I site located within the spacer region of the plasmids. The optimal spacing for expression of IFN-beta 1 was determined to be 8-13 nucleotides from the results of interferon assay. The E. coli lipoprotein (lpp) promoter was also used for expression of IFN-beta 1 in E. coli. The results with an expression vector carrying a lpp-lac promoter showed that a modified IFN-beta 1 containing an additional 7 amino acids at the amino-terminus might be less active than the mature molecule.

Amino Acid Sequence↗
PubMed1984

Protoplast transformation of glutamate-producing bacteria with plasmid DNA.

A method for polyethylene glycol-induced protoplast transformation of glutamate-producing bacteria with plasmid DNA was established. Protoplasts were prepared from cells grown in the presence of penicillin by treatment with lysozyme in a hypertonic medium. The concentration of penicillin during growth affected the efficiency of formation, regeneration, and polyethylene glycol-induced DNA uptake of protoplasts. Regeneration of protoplasts was accomplished on a hypertonic agar medium containing sodium succinate and yeast extract. The spectinomycin and streptomycin resistance plasmid pCG4, originally from Corynebacterium glutamicum T250, could transform various glutamate-producing bacteria such as C. glutamicum, Corynebacterium herculis, Brevibacterium flavum, and Microbacterium ammoniaphilum. The plasmid was structurally unchanged and stably maintained in new hosts. The transformation frequency of most competent protoplasts with pCG4 DNA isolated from primary transformants was high (ca. 10(6) transformants per microgram of covalently closed circular DNA) but was still two orders of magnitude below the frequency of transfection with modified DNA of the bacteriophage phi CGI. The difference was ascribed to the involvement of regeneration in transformation.

Brevibacterium↗