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Biomedical subjects

T Tachikawa

Publications and source records attributed to T Tachikawa.

At least 55 records · Page 3Linked to original sources
PubMed1996

Wound healing effect of malotilate in rats.

The wound healing effect of malotilate (CAS 59937-28-9, NKK-105) was investigated by using an excisional skin-wound model produced on the back of normal and healing-impaired (induced by prednisolone pretreatment) rats. The rapid decrease in the square measure of wound areas and the improvement in the histological evaluation clarified that 0.3% and 1% cream preparations of malotilate were obviously effective in accelerating spontaneous healing in the normal rats. The accelerative effect of malotilate cream preparations was likely superior to that of an ointment containing 5% deproteinized calf blood extract used as a reference agent. The same effect was also observed in the healing-impaired rats. The histological findings revealed that a thicker and more cellular granulation tissue, which in turn created an adequate bed for rapid re-epithelization, was formed in the malotilate-treated animals. Acceleration of granulation tissue formation by malotilate was also supported by the cotton pellet implantation method. It is concluded from these results that malotilate seems to be a promising agent for topical wound therapy.

Administration, Topical↗
PubMed1996

Periodontal tissue regeneration using fibrin tissue adhesive material in vitro and in vivo.

The purpose of this study was to determine the effects of a fibrin tissue adhesive material (FAM) on periodontal tissue regeneration. In an in vitro study comparing osteogenic cells with gingival fibroblasts, it was shown that the degradation of FAM adjacent to the osteogenic cells was faster than that adjacent to the gingival fibroblasts. In two in vivo studies in dogs where surgical bony defects were created, it was shown through histometric measurements that in the sites where FAM was applied, more new bone was found than in the control sites. It was concluded that FAM may enhance periodontal tissue regeneration.

Alveolar Bone Loss↗
PubMed1996

[Mechanism of cisplatin and peplomycin therapy on head and neck carcinoma].

Results of chemotherapy for head and neck cancer are now improving owing to the development of concomitant use of chemotherapeutic agents such as cisplatin or peplomycin. Concomitant use of the two agents has been favored clinically. However, fundamental study on the combination therapy has not been carried out sufficiently. In the present study we studied the cell kinetics of tumor cells by the combination of cisplatin and peplomycin using flowcytometric analysis and electron microscopy. Survival of tumor cells was lowest, when peplomycin was administrated 3 days after cisplatin. Cell kinetics showed an accumulation at the S and G2M stage in this situation, By the electron microscopic study, microvilli of tumor cells disappeared and the blebbing of tumor cells was observed, when cisplatin alone was administrated. However, when the combination of cisplatin and peplomycin was administrated to the tumor cells, tumor cells enlarged. The results suggest that the mechanism of combination therapy differed from the mechanism of cisplatin alone.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

[A nation-wide survey on the occurrence of amoebic keratitis in Japan].

Acanthamoeba keratitis in Japan was first reported by Ishibashi in 1988. Since then, the incidence of Acanthamoeba keratitis has gradually increased. We retrospectively analyzed 39 cases, 42 eyes, of amoebic keratitis reported in Japan from 1988 to September 1993. Of the 39 patients, 35 (89.7%) wore contact lenses, 32 (82.1%) soft contact lenses, and 3 (7.7%) hard contact lenses, and 4 (10.3%) did not wear contact lenses. Of the 4 patients without contact lenses, 3 had a history of trauma. Acanthamoeba keratitis is often difficult to diagnose. Twenty-four cases were misdiagnosed as herpetic keratitis. Early diagnosis and adequate therapy are important.

Acanthamoeba Keratitis↗
PubMed1994

Histomorphometric examination of healing around hydroxylapatite implants in 60Co-irradiated bone.

The purpose of this study was to histomorphometrically evaluate the use of hydroxylapatite (HA) implants in 60Co-irradiated bone. HA implants were installed in rabbit mandibles 3 months, 6 months, and 12 months after 15-Gy irradiation. Nonirradiated rabbits served as controls. The rabbits were killed 7, 14, 30, 60, and 90 days after the HA implantation. The histologic features of the healing process were examined and histomorphometric measurements were made to quantify the percentage of HA-bone contact and trabecular bone in the medullary cavity. In the irradiated groups, although HA-bone contact was observed later than that in the controls, recovery increased with time after irradiation and the rate of HA-bone contact bone-contacting implant surface ratio; BCSR exceeded 90% in all groups examined before 90 days. In the radiated groups, the average trabecular bone-specific volume was lower than that in the controls and began to decrease before BCSR exceeded 90%. Based on the present data, as well as data from the literature, it is suggested that the success rate of HA implants in irradiated bone increases with the interval after radiotherapy. It is also recommended that HA implants in irradiated bone be installed so that bearing by the cortical bone is increased.

Animals↗
PubMed1994

Local injection of OK-432/fibrinogen gel into head and neck carcinomas.

Immunotherapy with biological response modifiers (BRM) is a possible strategy against head and neck solid tumours. However, the rapid disappearance of BRM from the tumour area is one of the reasons for its limited clinical application. In this pilot study, fibrinogen gel containing OK-432 (a compound composed of attenuated Streptococcus pyogenes), an inducer of natural killer cells and T-cell cytotoxity, was injected directly into head and neck solid tumours of 15 patients. A dose of 5 Klinische Einheiten (KE) of OK-432 was reconstituted in 1 ml aprotinin and mixed with fibrinogen, the latter to maintain the OK-432 locally. 3 patients showed tumour regression, and in addition, we observed histological changes in the injected tumour of all patients. These results suggest that OK-432/fibrinogen gel generates a local immune response, leading to tumour regression.

Adult↗
PubMed1994

Growth and differentiation properties of normal and transformed human keratinocytes in organotypic culture.

The growth and differentiation of human normal keratinocytes and their transformed counterparts were examined in organotypic cultures in which the keratinocytes were grown at the air-liquid interface on top of contracted collagen gel containing fibroblasts. We developed a modified culture procedure including the use of a mixed medium for keratinocytes and fibroblasts. Normal keratinocytes formed a three-dimensional structure of epithelium that closely resembled the epidermis in vivo, consisting of basal, spinous, granular and cornified layers. Cells synthesizing DNA were located in the lowest basal layer facing the collagen gel. Expressions of proteins involved in epidermal differentiation were examined by immunohistochemical staining and compared with those in skin in vivo. In the organotypic culture, transglutaminase, involucrin and filaggrin were expressed, as in the epidermis in vitro, most prominently in the granular layer. Type IV collagen, a component of basement membrane, was expressed at the interface between the keratinocyte sheet and the contracted collagen gel. Keratinocytes transformed by simian virus 40 or human papilloma virus (HPV) exhibited a highly disorganized pattern of squamous differentiation. In particular, HPV-transformed cells invaded the collagen gel. Organotypic culture is unique in that regulatory mechanisms of growth and differentiation of keratinocytes can be investigated under conditions mimicking those in vivo.

Antigens, Differentiation↗
PubMed1994

Enzyme immunoassay for erythrocyte aldose reductase.

This two-site immunoassay measures erythrocyte aldose reductase by using monoclonal and polyclonal antibodies to recombinant human enzyme. Total incubation time is 2.5 h, and the limit of detection is < 0.05 microgram/L. Analytical recovery tested with blood samples from healthy and diabetic individuals was 101-106%. Average CVs within and between assays were 3.7% and 4.8%, respectively. The enzyme content determined by this system correlated well with the activity of aldose reductase isolated from the same erythrocyte preparations. The amount of erythrocyte aldose reductase per milligram of hemoglobin was higher in women than in men (P < 0.001), but no significant correlation was observed between the amount of enzyme and the age of the individuals. This assay method should provide useful clinical information to optimize administration of aldose reductase inhibitors for effective prevention and treatment of diabetic complications.

Adult↗
PubMed1993

Influence of LAK cells on expression of HLA-DR antigen on laryngeal carcinoma cell line in new culture systems.

We demonstrated the enhancement of HLA-DR antigen expression on cultured laryngeal carcinoma cells (Hep 2) by in vitro cultivation with LAK cells using flow cytometric and immunohistological analysis. For in vitro cultivation of tumor cells with LAK cells, we used newly developed experimental systems (the Transwell double-dish system and experimental three-dimensional tumors). In flow cytometric analysis, expression of HLA-DR antigen on tumor cells was compared before and after co-cultivation with LAK cells. When tumor cells were cultured separately with LAK cells in a Transwell Petri dish and the expression of HLA-DR antigen on tumor cells was analyzed by flow cytometry, the expression of HLA-DR antigen on tumor cells was increased in a dose-dependent manner related to the number of LAK cells used. Furthermore, when anti-interferon-gamma monoclonal antibody was added to the experimental system, enhancement of HLA-DR antigen expression was blocked. These findings were consistent with immunohistological studies, in which experimental three-dimensional Hep 2 cell tumors were established in double-layered agar with/without being co-cultivated with LAK cells. The expression of HLA-DR antigen in this system was significantly increased when compared to such expression before cultivation with LAK cells. These findings suggested that the culture systems employed in this study could be a possible model for examining solid tumor in vivo biological responses. This enhanced expression of HLA-DR antigen may also represent one of the multi-factorial responses seen with adoptive LAK cell immunotherapy for solid tumors.

Antigens, Surface↗
PubMed1993

Effect of calcium phosphate ceramic particle insertion on tooth eruption.

The effects of calcium phosphate ceramic implants on tooth eruption were investigated radiographically and histologically in 20 3-month-old dogs. Four kinds of ceramic particles were used: dense and porous hydroxyapatite particles, and dense and porous tricalcium phosphate particles. These particles were implanted in the sockets after deciduous tooth extraction. The four types of calcium phosphate ceramic particles produced similar radiographic and histologic findings. There was no delay of tooth eruption, no dysplasia, and no resorption of dental hard tissue.

Animals↗
PubMed1993

Aberrant alpha 1-->2fucosyltransferases found in human colorectal carcinoma involved in the accumulation of Leb and Y antigens in colorectal tumors.

Evidence indicates that the presence of aberrant alpha 1-->2fucosylation pathways is responsible for the accumulation of large quantities of Le(b) and Y antigens in human colorectal carcinoma. Significantly higher activities of alpha 1-->2 as well as alpha 1-->3 and alpha 1-->4fucosyltransferases were found in most of the tissues from carcinoma than in the adjacent normal tissues and in healthy subjects. alpha 1-->2Fucosyltransferases associated with the synthesis of Le(b) (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and Y (Fuc alpha 1-->2Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) structures from Le(a) (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and X (Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) ones, respectively, were demonstrated in colorectal carcinomas and in colorectal carcinoma cell lines (COLO201, LS174T and SW1116). The activation of alpha 1-->2fucosyltransferase with such new substrate specificities in colorectal carcinoma might result in the preferential synthesis of Le(b) and Y structures from Le(a) and X rather than from H type 1 and H type 2 structures.

Blood Group Antigens↗
PubMed1993

Development and characterization of a novel anti-fucosylated antigen monoclonal antibody YB-2 and its usefulness in the immunohistochemical diagnosis of colorectal cancer.

A novel monoclonal antibody, YB-2 was obtained after immunization of mice with fucosylated antigens isolated from human saliva. The antibody was demonstrated to react with Y (Fuc alpha 1-->2Gal-beta 1-->4[Fuc alpha 1-->3]GlcNAc beta),Leb (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and H type 2 (Fuc alpha 1-->2Gal-beta 1-->4GlcNAc beta) antigens, but not with H type 1 (Fuc alpha 1-->2Gal beta 1-->3GlcNAc beta), Lea (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), X (Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) or with non-fucosylated antigens. Inhibition assays of YB-2 antibody with such reactive antigens showed that YB-2 antibody preferentially reacted with Y antigen. Formalin-fixed and paraffin-embedded sections prepared from normal and malignant colorectal tissues were examined immunohistochemically with YB-2. The positive rates of staining with YB-2 antibody were 88.6% in malignant and 12.0% in normal tissues. The expression of fucosylated antigens detected by YB-2 antibody seemed to be correlated with survival among patients with primary colorectal cancer. Therefore, YB-2 antibody could be useful as an immunochemical tool for diagnosis and evaluation of the prognosis of colorectal cancer.

Antibodies, Monoclonal↗
PubMed1993

Inhibition of head and neck tumor cell colony growth by lymphokine activated killer cells.

The antiproliferative effect of lymphokine activated killer (LAK) cells on head and neck tumor cells has not previously been elucidated. We studied the inhibitory effects of recombinant interleukin-2 activated lymphocytes on tumor colony formation in semisolid agar, using head and neck tumor cells prepared from established tumor cell lines (K562, HT29, HLaC78) and xenografted head and neck squamous cell carcinomas on nude mice (XKN, XLL, XFL, XKF). LAK cells demonstrated a significant inhibitory effect on colony formation. The effects of LAK cells on cultured tumor cell lines were evaluated in a dose dependent manner using effector: target ratios. In addition, the colony formation of tumor cells derived from xenografted nude mouse was inhibited by LAK cells. These results suggest that LAK cells generate an antiproliferative effect on head and neck tumor cells.

Adenocarcinoma↗
PubMed1993

Chemosensitivity testing of human mouth carcinoma cell line.

The chemosensitivity of KB cells derived from oral epidermal carcinoma to various antitumor agents was analyzed using the MTT[3-(4,5-dimethyl-2-thiazoyl)-2,5-diphenyl-2H tetrazolium bromide] assay. Optical density (OD) for MTT assay was measured with dual wavelengths. The chemosensitivity of the drugs was evaluated by the 50% OD (OD50) of each drug concentration in the control group. Five platinum (Pt) drugs and 3 anthracycline (AC) drugs were used in this study. The chemosensitivity differed among the 5 Pt drugs. No significant difference was observed among the 3 AC drugs. A linear increase in OD corresponding to an increase in number of cells was observed. When 0.1 M sodium succinate (S.S.) was added to 0.4% MTT, the sensitivity increased five-fold compared to the control group without S.S. The MTT assay is a precise, rapid, easy and inexpensive experimental system useful for evaluation of antitumor drug sensitivity on tumor cell lines.

Antibiotics, Antineoplastic↗
PubMed1993

[Antitumor effect of LAK cells on CDDP resistant head and neck carcinoma cell line].

Antitumor effects of lymphokine-activated killer (LAK) cells on cisplatin resistant oral carcinoma cell line were evaluated in vitro by 51Cr release assay and in vivo by nude mouse model. Oral carcinoma cell line (KB) and its subline KBrc resistant to cisplatin were used as target cells. We observed the antitumor effect of LAK cells on both KB and KBrc cells in terms of cytotoxicity of 51Cr release assay, and tumor growth inhibition of nude mouse assay. However, when we compared the antitumor effect between KB and KBrc cells, KBrc cells demonstrated a significant decrease in susceptibility to killing by LAK cells in the in vitro and in vivo model in comparison with the antitumor effect of LAK cells on KB cells. These results, which were not similar to the results of previous studies reported, suggest that alternations of characteristics of tumor cells such as acquired drug resistance result in the decrease in susceptibility of tumor cells against LAK cells.

Animals↗
PubMed1992

Sialosyl-Tn antigen. Its distribution in normal human tissues and expression in adenocarcinomas.

In normal adult human tissues, sialosyl-Tn antigen, detected by monoclonal antibody TKH2, was uniformly found in the bronchus, uterus, salivary gland, palatine tonsil, testis, stomach, duodenum, and capillary endothelium of several organs. It was also sporadically found in the small intestine, appendix, colorectum, gallbladder, urinary bladder, skin, and esophagus. The antigen was absent in the other organs. Even in the organs showing positive findings, the antigen was observed only in the limited areas. In contrast, sialosyl-Tn antigen was expressed in a large number of adenocarcinomas in many kinds of organs. It was expressed in more than one half the adenocarcinomas of the pancreas, ovary, uterus, stomach, colorectum, and gallbladder, but not in hepatocellular carcinomas, renal cell carcinomas, and papillary carcinomas of the thyroid gland. Sialosyl-Tn antigen expression also was observed in intestinal metaplasia of the stomach and in transitional mucosa adjacent to the colorectal carcinoma, which are considered to be cancer-related lesions. These results indicate that sialosyl-Tn antigen is a useful tumor marker, especially in adenocarcinomas of the mucin-producing organs, and suggest that the regulation of sialosyl-Tn antigen synthesis in adenocarcinomas is different from that in normal tissues.

Adenocarcinoma↗
PubMed1992

Use of synthetic H disaccharides as acceptors for detecting activities of UDP-GalNAc:Fuc alpha 1-->2Gal beta-R alpha 1-->3-N-acetylgalactosaminyltransferase in plasma samples from blood group A subgroups.

Concentrations of blood group A-specified alpha(1-->3)-N-acetylgalactosaminyltransferase (A enzyme) were measured in human plasma of blood groups A1, A2, and A3 by using chemically synthesized H disaccharides and H type 1 and type 2 trisaccharides attached to hydrophobic aglycones as acceptors. When the trisaccharides were used as acceptors, enzyme activities were reduced in samples from A2 and A3. However, the H disaccharides were shown to be good acceptors even for enzymes from A2 and A3, and no significant difference in enzyme concentration was detected in any of the plasma tested.

ABO Blood-Group System↗