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Biomedical subjects

T Yanagawa

Publications and source records attributed to T Yanagawa.

At least 127 records · Page 7Linked to original sources
PubMed1990

Use of tumor diameter to estimate the growth kinetics of cancer and sensitivity of screening tests.

A statistical method has been developed that is useful for studying the relationship between the growth kinetics of malignant tumors and the detection probability either through symptoms or by screening. Mathematical models that describe the distribution of pathological variables in malignant tumors, detected after various histories of screening, are derived and parameters for detection probabilities and the growth kinetics are then estimated by the maximum likelihood procedure. By this method the probabilities of detection through symptoms as well as by screening can be estimated as functions of pathological variable(s) such as tumor size. The growth rate of tumor can also be estimated from the distribution of pathological variables. The present method was applied to gastric cancer in Japan, where an annual screening program for the disease exists. The detection probability for the indirect X-ray used as the screening test was estimated to be 0.323 x (diameter)2/[1 + 0.323 x (diameter)2]. The doubling time of gastric cancer was estimated to be 2.90 months.

Cell Cycle↗
PubMed1990

Use of screening tests to assess cancer risk and to estimate the risk of adult T-cell leukemia/lymphoma.

We developed methods to assess the cancer risks by screening tests. These methods estimate the size of the high risk group adjusted for the characteristics of screening tests and estimate the incidence rates of cancer among the high risk group adjusted for the characteristics of the tests. A method was also developed for selecting the cut-off point of a screening test. Finally, the methods were applied to estimate the risk of the adult T-cell leukemia/lymphoma.

Adult↗
PubMed1990

Induction of bone formation in an adenoid cystic carcinoma of the maxillary sinus by adoptive immunotherapy involving intra-arterial injection of lymphokine-activated killer cells and recombinant interleukin-2 in combination with radiotherapy.

A patient with an adenoid cystic carcinoma of the maxillary sinus was treated by adoptive immunotherapy involving intra-arterial injection of lymphokine-activated killer cells (a total number of 7 x 10(7) cells) and recombinant interleukin-2 (a total dose of 2.75 x 10(7) units) in combination with radiotherapy (60Co; total irradiation dose of 5,000 rads). Consequently, it was found that bone formation was induced in the treated tumor, which was then replaced completely by lamellar bone tissue with myxomatous stroma. This finding indicates that the tumor cells composing certain adenoid cystic carcinoma can be converted into normal-appearing, bone-forming cells by current therapy and this differentiation phenomenon leads to cure of the tumor.

Biopsy↗
PubMed1989

Expression of neurofilaments in a neoplastic human salivary intercalated duct cell line or its derivatives and effect of nerve growth factor on the cellular proliferation and phenotype.

A neoplastic salivary cell line with an ultrastructure similar to that of an intercalated duct cell of the salivary gland, established from a human submandibular salivary gland, has been used in our laboratory as a model for studying mechanisms regulating cytodifferentiation in salivary glands. The expression of neurofilaments (Mr 200,000, 160,000, and 68,000) in the neoplastic human salivary intercalated duct cell line and its derivatives was found by the immunofluorescence staining technique, immunoblotting, or immunoelectron microscopy. In addition, these cells stained with Bodian impregnation and expressed specific antigens such as tubulin alpha and beta chain, HNK-1 antigen, and laminin. When these cells were cultured in the presence of nerve growth factor, only the cells with a myoepithelial cell phenotype formed the long cytoplasmic processes which were densely packed with ample microfibrils in addition to microtubule bundles, and they exhibited marked suppression of anchorage-independent and anchorage-dependent growths. These findings indicate that the characteristics of neoplastic human salivary intercalated duct cell line and its derivatives are similar to those of neuronal cells.

Biomarkers↗
PubMed1989

Induction of cells with a chondrocyte-like phenotype by treatment with 1 alpha,25-dihydroxyvitamin D3 in a human salivary acinar cell line.

A clonal cell with an acinar cell phenotype, which was induced by 5-azacytidine treatment of a neoplastic human salivary intercalated duct cell line, was cultivated in the presence of 1 alpha,25-dihydroxyvitamin D3. Morphological changes occurred; large cells that were polygonal or round in shape and had numerous vacuoles in their cytoplasm appeared in the treated cells, whereas the same concentration of 1 alpha,25-dihydroxyvitamin D3 did not affect the morphology of the parental cells. Major alterations, such as expression of type II collagen, alpha and beta chains of S-100 protein, and sulfated proteoglycans, were observed in these cells with a phenotype similar to chondrocytes. After the removal of 1 alpha,25-dihydroxyvitamin D3 from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that the reversible differentiation into chondrocyte-like cells of a human salivary acinar cell line occurs in growth medium containing 1 alpha,25-dihydroxyvitamin D3.

Calcitriol↗
PubMed1989

Prevalence of HTLV-I-associated myelopathy among HTLV-I carriers in Saga, Japan.

Surveying the disease by sending questionnaires to all physicians of the Saga Medical Association, we tabulated 19 definite cases of HTLV-I-associated myelopathy (7 males and 12 females) as of January 31, 1988. The population at risk of HTLV-I carriers was estimated by applying sex- and age-specific anti-HTLV-I antibody-positive rates among blood donors at the Saga Red Cross Blood Center in the fiscal year of 1986 to the population of Saga Prefecture in 1982. The crude prevalence rates among HTLV-I carriers from 20 to 69 years of age per 100,000 were 65.7 for males and 86.9 for females, respectively. The summary prevalence rates with 95% confidence intervals were 46.5 (14.3-97.3) for males and 74.9 (35.3-129.2) for females. There was no remarkable difference in the age-specific prevalence rates in either sex. The crude and summary rates among females were higher than those among males, but the difference was not statistically significant.

Adult↗
PubMed1989

Dentin adhesive containing 4-META. Effect of a cleanser on bonding.

The effect of the cavity cleanser on the efficacy of the experimental dentin bonding system, which was composed of dentin primer (aqueous solution of 35% hydroxyethyl methacrylate), a dentin bonding agent containing a functional monomer (4-methacryloxyethyl trimellitate anhydride), and an urethane dimethacrylate based composite resin was examined. The bonding efficacy was evaluated by measuring the contraction gap in an experimental cavity which had both an enamel and a dentin cavity margin, and by measuring the tensile bond strength to the flat tooth surface. The whole cavity was cleaned by neutralized 0.5 M EDTA or 10% citric acid containing 3% ferric chloride (10-3 solution) prior to the application of the dentin primer. For the control, the enamel and dentin were etched and cleaned with a 38% phosphoric acid gel and EDTA respectively. It was possible to conclude that the cavity cleanser employing the 10-3 solution for 5s was effective both in cleaning to the dentin and the enamel cavity walls.

Acrylic Resins↗
PubMed1989

Monoclonal antibody to a human salivary gland adenocarcinoma cell line: augmentation of antibody-dependent cell-mediated cytotoxicity activity by streptococcal preparation OK-432 in human salivary gland adenocarcinoma-bearing nude mice given the antibody.

An IgG2a mouse monoclonal antibody (MoAb) to the human salivary gland adenocarcinoma cell line HSG, 5B/10, has been generated in our laboratory. In the current study, the antitumor effects mediated by MoAb 5B/10 in human salivary gland adenocarcinoma (HSG)-bearing nude mice or the antibody-dependent cell-mediated cytotoxicity (ADCC) against HSG cells using human peripheral blood mononuclear cells (PBMC) as effector cells were examined. In addition, effects of the streptococcal preparation OK-432 on the growth of HSG tumors or on the MoAb 5B/10-mediated cellular cytotoxicity were studied. MoAb 5B/10 mediated an ADCC reaction against HSG cells that were insensitive to NK cells but not to the reaction of antibody and complement-mediated cytotoxicity. The coexistence of MoAb 5B/10 and OK-432 caused marked augmentation of cytotoxic effects. Treatment of OK-432-stimulated PBMC with antiasialo Gm1 antiserum plus complement but not with silica particles resulted in a significant decrease of cytotoxic effects as compared with relevant controls. the nude mice inoculated intraperitoneally with HSG cells and treated with MoAb 5B/10, OK-432, or (especially) a combination of the two had significantly prolonged survival times as compared with untreated controls. Moreover, spleen cells from the tumor-bearing mice treated with OK-432 alone or a combination of MoAb 5B/10 and OK-432 were found to carry high levels of effector cell activity in the MoAb 5B/10-mediated cytotoxicity assay using HSG cells as targets.

Adenocarcinoma↗
PubMed1989

[Dentigerous cysts of children treated by cyst wall enucleation. Report of eleven cases].

The present paper describes ten children with eleven cases of dentigerous cysts which were treated by extraction of the primary teeth, cyst wall enucleation and lingual-arch spacemaintainer. The patients were seven boys and three girls, with a mean age of nine years two months, in Hellman's Dental Age IIIA and IIIB. In eight of the cases, the mandibular second premolar was involved, and of the remainder, two cases involved the first premolar, and one case, a maxillary lateral incisor. In eight out of the eleven cases, the pulp of the primary tooth had been treated. Radiographically, nine cases exhibited a pericoronal space of 15 mm-35 mm and two cases 50 mm-55 mm. The material for histological examination, typically, gave the appearance of a stratified squamous epithelium showing chronic inflammation. Healing took place more rapidly than routine marsupialization. In eight cases the successor erupted in the normal position without orthodontic treatment, in two cases with light orthodontic power. In one case the behavior of the permanent tooth was kept under observation. From the above, this approach to treatment by cyst wall enucleation and lingual-arch spacemaintainer would appear to be very useful for the young child.

Child↗
PubMed1989

Insulin autoantibodies in mouse models of insulin-dependent diabetes.

To clarify the significance of insulin autoantibodies (IAA) in insulin-dependent diabetes mellitus, we measured the IAA longitudinally in non-obese diabetic (NOD) mice, and in high-dose streptozotocin-induced diabetes (high-SZ) and EMC virus-induced diabetes (EMC) in mice, and compared the data with the occurrence of insulitis. The IAA were detected by the polyethylene glycol (PEG) method using 125I-(Tyr A14) human insulin. The IAA were found in 38% of NOD mice and correlated with the occurrence of insulitis. The prevalence of IAA was 0% before the appearance of insulitis, 80% at 12-14 weeks of age and 30% after 20 weeks of age in female NOD mice. In male NOD mice, IAA were found in 45% at 12-14 weeks of age and 20% after 20 weeks. In high-SZ mice, IAA were detected in several mice while insulitis was not present. In EMC-virus induced diabetic mice, IAA and lymphocytic infiltration into the islets were detected 4-14 days after EMC virus infection. These results suggest that (a) IAA are markers for islet autoimmunity in NOD mice, (b) the presence of IAA does not always reflect insulitis, (c) the presence of IAA is not sufficient for the development of overt diabetes and (d) the appearance of IAA may reflect a difference of the immune response genotype.

Animals↗
PubMed1989

[Klebsiella pneumoniae meningitis associated with liver abscess: a case report].

We report a rare case of Klebsiella pneumoniae meningitis associated with liver abscess, which was successfully treated with cefotaxime (CTX), one of the third-generation cephalosporins. A 53-year-old man was admitted to Keio University Hospital on June 13, 1988, because of a fever and a headache. On June 3, he suddenly started shivering and his temperature rose to 39 degrees C. He then began to complain of polydipsia, polyuria, and a weight loss of 4 kg a week. On June 11, he developed a severe headache. Four years prior to this incident, he had been diagnosed as having diabetes after a routine medical examination, but had neglected to undergo medical treatment. On admission, laboratory data showed leukocytosis, hyperglycemia (394 mg/dl) and ketonuria (4+). A lumbar puncture yielded cloudy cerebrospinal fluid (CSF) containing 500/3 cells/mm8, of which about 70% were neutrophils. A diagnosis of diabetic ketoacidosis and purulent meningitis was made. A treatment with ampicillin (ABPC) and CTX, (12 g/day, each) was begun. On the third day, cultures of a blood specimen and CSF yielded both K. pneumoniae. The MICs of CTX to K. pneumoniae isolated from blood and CSF were both 0.05 microgram/ml. ABPC was discontinued, gentamicin was administered for 2 days, CTX was continued at the same dosage level and an administration of prednisolone 40 mg daily was begun.(ABSTRACT TRUNCATED AT 250 WORDS)

Cefotaxime↗
PubMed1989

The suppressive effect of cyclophosphamide on low-dose streptozotocin-induced diabetes in mice.

We found that low-dose streptozotocin (SZ)-induced diabetes in mice is suppressed by cyclophosphamide (CY) and studied the mechanisms of this suppression. Male CD-1 mice were injected intraperitoneally with SZ (40 mg/kg) for five consecutive days (group SZ). In addition, CY (200 mg/kg) was injected on the first day (group CY-1) or on days 1 and 5 (group CY-2). In group SZ, all mice developed diabetes within nine days after the first injection of SZ. Group CY-1 did not develop hyperglycemia for 14 days and group CY-2 did not develop it throughout the experimental period (40 days). Insulitis was suppressed slightly in group CY-1 and completely in group CY-2. The number of spleen cells did not change in group SZ compared with that before cyclophosphamide treatment. They decreased significantly on days 3 and 7 in both groups CY-1 and CY-2 (p less than 0.01 or p less than 0.05), but then increased significantly on days 14 and/or 21 (p less than 0.01 or p less than 0.05) compared with those before cyclophosphamide treatment. The Thy 1.2- and L3T4-positive cells increased significantly in group SZ but they decreased on days 3 and 7 in both groups CY-1 and CY-2 (p less than 0.01) compared with the controls. These results suggest that (1) this large reduction of lymphocytes at the beginning of SZ treatment may lead to the prevention of hyperglycemia and insulitis, and (2) T-cells, especially L3T4-positive cells may play an important role in the pathogenesis of this type of diabetes.

Animals↗
PubMed1988

Effects of retinoic acid on morphological features and biological markers of a neoplastic human salivary intercalated duct cell line in culture.

Retinoic acid has marked effects on the growth, morphological features, and biological markers of a neoplastic human salivary intercalated duct cell clone in culture, whereas the cell clone was not affected by other retinoids such as retinol and retinal. A cell clone with ultrastructure and biological markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of retinoic acid. Major alterations, such as expression of tonofilaments, Mr 68,000 cytokeratin, and involucrin, were observed in those cells with a phenotype similar to that of keratinizing squamous cells. In addition, the coexpression of Mr 68,000 cytokeratin and carcinoembryonic antigen in these altered cells was found. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of retinoic acid. After the removal of retinoic acid from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the keratinizing squamous cells of a neoplastic human salivary intercalated duct cell clone occurs in growth medium containing retinoic acid.

Adenocarcinoma↗
PubMed1988

Cellular proliferation and ras oncogene of p21 21,000 expression in relation to the intracellular cyclic adenosine 3':5'-monophosphate levels of a human salivary gland adenocarcinoma cell line in culture.

We have found that reversible differentiation into the myoepithelial cells of a human salivary gland adenocarcinoma cell line (HSG) occurs in growth medium containing dibutyryl cAMP (dB-cAMP). In the current study, the relationship between intracellular cAMP levels and anchorage-dependent and -independent growth or ras oncogene of p21 levels was analyzed in the differentiation process toward myoepithelial cells of HSG cells cultured in the presence of dB-cAMP. Correlation between the concentrations of dB-cAMP and intracellular cAMP in the HSG cells was statistically significant. There was a significant inverse correlation between the concentrations of dB-cAMP and colony-forming ability of the cells in semisolid agar or on a plastic surface. We have found the expression of ras p21 protein in HSG cells. When HSG cells were cultured in the presence of dB-cAMP and were committed to differentiate into myoepithelial cells, it was shown by double-antibody labeling technique and/or immunoblotting that the committed cells expressed myosin with a concomitant decrease of ras p21 protein. Moreover, intracellular cAMP levels were found to be inversely associated with ras p21 content of the cells. These findings indicate that the intracellular cAMP levels regulate significantly cell proliferation and ras p21 expression in HSG cells.

Adenocarcinoma↗
PubMed1988

Enhancement of cis-diamminedichloroplatinum and mitomycin C-induced sister chromatid exchanges by dibutyryl cyclic AMP in a human salivary gland adenocarcinoma cell line in culture.

A human salivary gland adenocarcinoma cell line was cultivated in the presence of dibutyryl cyclic AMP (dB-cAMP), cis-diammine dichloroplatinum (cisplatin) or mitomycin C (MMC) only, or of the combination of dB-cAMP and each of the antineoplastic drugs. Then the treated cells were examined for the induction of sister chromatid exchanges (SCEs), colony-forming efficiency (CFE) in semisolid agar medium and cell survival as measured by counting for viable cells. It has been found that the frequency of SCE induction is significantly increased by treatment of cells with cisplatin or MMC under the presence of dB-cAMP, when compared to that in the cells treated with cisplatin or MMC only. Moreover, marked reduction in CFE and cell survival was found to occur in the cells treated with the combination of dB-cAMP and cisplatin or MMC. These finding indicate that treatment of a human salivary gland adenocarcinoma cell line with dB-cAMP results in modification of SCE induction, CFE and cell survival in the cells exposed to cisplatin or MMC.

Adenocarcinoma↗
PubMed1988

Insulin autoantibodies in non-obese diabetic (NOD) mice and streptozotocin-induced diabetic mice.

Similar to Insulin-dependent diabetes mellitus (IDDM) in man, diabetes in the non-obese diabetic (NOD) mouse and that induced by low-dose of multiple injections of streptozotocin (low-dose SZ) develop in conjunction with the presence of insulitis. We measured insulin autoantibodies (IAA) in NOD and low-dose SZ mice and compared the levels with mice given a single diabetogenic dose of streptozotocin (high-dose SZ) as well as control CD-1 mice. The mean insulin binding in female NOD mice was 3.08 +/- 1.49 (mean + SD)% and that in male NOD mice was 2.86 +/- 3.70%, as compared with 1.10 +/- 0.35% in the control CD-1 mice (p less than 0.01, p less than 0.05). Sera from low-dose SZ and high-dose SZ mice showed 1.07 +/- 0.23% and 0.93 +/- 0.45% of IAA which did not differ from controls. The number of mice with IAA above the mean + 2SD value of CD-1 mice were 8/9 female NOD mice and 9/20 male NOD mice. Insulitis was found in all NOD and low-dose SZ mice but not in any high-dose SZ mice and control CD-1 mice. These results suggest that (a) IAA are markers for islet autoimmunity in the NOD mouse, (b) presence of IAA does not reflect insulitis, and (c) the appearance of IAA may reflect a difference of the immune response genotype.

Animals↗