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Biomedical subjects

Y Adachi

Publications and source records attributed to Y Adachi.

At least 703 records · Page 39Linked to original sources
PubMed1990

Protein kinase inhibitor H-7 blocks accumulation of unspliced mRNA of human T-cell leukemia virus type I (HTLV-I).

Rex, the post-transcriptional regulator of human T-cell leukemia virus type I (HTLV-I), is known to induce accumulation of the unspliced viral gag-pol mRNA. Rex is a phosphoprotein found in the cell nucleolus, whose function may be regulated by its localization and phosphorylation. We have examined the role of phosphorylation on Rex function by using a protein kinase inhibitor, H-7 [1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine]. Treatment of an HTLV-I infected human T-cell line with H-7 blocked specifically accumulation of the unspliced gag-pol mRNA, resulting in the decreased Gag protein synthesis that corresponds with the decreased in vivo phosphorylation of Rex. In contrast, other viral and cellular products have not been influenced by the level of H-7 used. Therefore, the phosphorylation of Rex is required for the viral RNA partition of HTLV-I.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

Advanced gastric carcinoma simulating early gastric carcinoma.

Eighty-six cases of advanced gastric carcinoma simulating early gastric carcinoma were studied clinicopathologically. Cytophotometric DNA analysis was also performed in 33 cases. Most of these particular carcinomas were of the depressed type on gross inspection. Histologically, the tumors were of diffuse type in 60%. The rate of the carcinomas restricted to within the muscularis propria was 48% and high in comparison with those in conventional advanced gastric carcinomas. There were four main growth patterns: small invasion type (Type A, 43 cases), ulcer-connected type (Type B, 19 cases), vessel permeation type (Type C, six cases), and diffusely infiltrative type (Type D, 13 cases). There was a relationship between growth patterns, lymph node metastasis, and prognosis: Types A and B had a small percentage of lymph node metastasis and a good prognosis, whereas Types C and D a high percentage and a poor prognosis. DNA analysis revealed that two thirds of the examined cases showed a low ploidy pattern. The DNA ploidy patterns were concerned with the tumor growth pattern: high-ploidy cases were rarely seen in Types A and B yet were frequent in Types C and D. The 5-year survival rate was 73%, but results were poor in cases of tumors with blood vessel permeation, in those with lymph node metastasis, in those with the Type D or C growth patterns, and in those with high DNA ploidy pattern. Since these carcinomas can be understaged endoscopically and by gross examination, a precise study of the surgically excised tissues will aid in making an accurate prognosis.

Adult↗
PubMed1990

Functional analyses of thymic CD5+ B cells. Responsiveness to major histocompatibility complex class II-restricted T blasts but not to lipopolysaccharide or anti-IgM plus interleukin 4.

The function of thymic B cells in several standard in vitro assays was investigated. Thymic B cells, 75% of which were CD5+, showed a poor responsiveness to the mitogens LPS or anti-mu plus IL-4. Both proliferation and antibody formation were much lower in thymic than splenic B cell cultures. However, CD5- B cells purified using a cell sorter responded well to B cell stimulants, whereas purified CD5+ thymic B cells did not, indicating that CD5+ thymic B cells were unresponsive to B cell growth factor or LPS. Thymic B cells could be activated polyclonally by direct interaction with alloreactive T blasts, as manifested by DNA synthesis and antibody formation. These findings indicate that CD5+ thymic B cells may not be stimulated via sIg and IL-4, but require instead direct interaction with T blasts.

Animals↗
PubMed1990

Spontaneous and cAMP-dependent induction of a resting phase and neurite formation in cell hybrids between human neuroblastoma cells and thymidine auxotrophs of rat nerve-like cells.

Cell hybrids (BIM) were produced between human neuroblastoma cells (IMR-32) and thymidine auxotrophs (B3T) of rat nerve-like cells (B103) in order to obtain cell lines undergoing stable neuronal differentiation. BIM cells exhibited the growth properties of partial transformation: 1) When the cell growth reached a plateau, BIM cells ceased to proliferate and expressed a differentiated phenotype. The shape of the cells changed from flat to round and they extended neurites. 2) When cultured in methylcellulose, BIM cells formed colonies, indicating that BIM cells have the ability of anchorage-independent growth. By Southern blot analysis, BIM cells had both human and rat types of N-myc genes. The human N-myc genes were amplified, but the extent of the amplification was lower in BIM cells than that in the parental cell line IMR-32. The rat N-myc gene was detected at a similar level in BIM, B3T, B103, and rat fibroblastic cells 3Y1. Therefore, the decrease in amplification of human N-myc genes may be involved in the properties of partial reverse-transformation in BIM cells. When treated with various drugs such as db-cAMP, forskolin, and cAMP with isobutyl-methylxanthine, BIM cells expressed a nerve-like phenotype. These findings indicate that cell hybridization yielded partial normalization of transformed nerve-like cells.

1-Methyl-3-isobutylxanthine↗
PubMed1990

Transitional mucosa in human colorectal lesions.

Mucosa adjacent to colorectal disease was studied mucin-histochemically. Selected specimens were also studied immunohistochemically for carcinoembryonic antigen (CEA). Transitional mucosa, which showed elongation of crypts and marked sialomucin secretion, accompanied by a marked reduction in the normal sulfomucin content, was evident in 96 of 100 carcinomas (96 percent), 18 of 36 adenomas (50 percent), and 10 of 30 metaplastic polyps (33 percent). When considering the appearance of transitional mucosa, not only in the neoplastic lesions such as carcinoma or adenoma but also in the begin polyp, the transitional change adjacent to the carcinoma cannot be classified as a precancerous phenomenon; rather, it is a secondary one. The mucin-histochemical study disclosed transitional mucosa in all the 21 carcinomas less than 1 cm in diameter and immunohistochemical staining for CEA showed no remarkable change in the adjacent mucosa. Thus, it seems apparent that a change in mucous secretion precedes that of CEA expression in the mucosa adjacent to the carcinoma.

Adenocarcinoma↗
PubMed1990

Depressed function of Kupffer cells in rats with CCl4-induced liver cirrhosis.

In the present study, the Kupffer cell function of rats with CCl4-induced liver cirrhosis was tested by analyzing the changes in the host defense system. In rats without liver cirrhosis injected with CCl4 for 3 weeks concomitant with the high opsonic activity the endocytic index was significantly increased. Rats treated for 9 and 13 weeks developed cirrhosis, and their endocytic indices were not increased despite the rise in their opsonic activity. Particularly, the endocytic index of 13-week-treated rats with advanced liver cirrhosis was significantly lower than that of the other groups. The organic distribution of 51Cr-endotoxin injected intravenously exhibited characteristic changes in 9-week- and 13-week-treated rats: decreased hepatic uptake and increased splenic uptake. In contrast, pulmonary uptake was increased in all CCl4-treated rats. The superoxide production by Kupffer cells from 13-week-treated rats was greatly reduced, accompanied by the decreased superoxide dismutase activity of liver homogenate. Thus, results of this study suggest that Kupffer cell dysfunction is one of the main factors affecting host defenses in liver cirrhosis.

Animals↗
PubMed1990

Proportion of conjugated bilirubin in bile in relation to hepatic bilirubin UDP-glucuronyltransferase activity.

To elucidate the diagnostic relevance of biliary conjugated bilirubin, biliary bilirubin from normal volunteers (NV), patients with Gilbert's syndrome (GS) and Crigler-Najjar syndrome type II (C-N II), and from various rat strains was fractionated. Biliary bilirubin diglucuronide (BDG) was present at lower levels, and bilirubin monoglucuronide (BMG) and unconjugated bilirubin were present at higher levels in GS and C-N II compared with NV, which is consistent with decreased hepatic bilirubin UDP-glucuronyltransferase activity (BGTA). The level of biliary BDG was higher in Wistar-Kyoto rats and lower in heterozygous (Jj) Gunn rats than in SD and Wistar rats. The hepatic BGTA level in heterozygous (Jj) Gunn rats was decreased to 60% of that in Wistar rats, in accordance with decreased biliary BDG. On the other hand, BGTA in Wistar-Kyoto rats whose biliary BDG level was high, was not different from that of Wistar and SD rats. Thus, a correlation between BGTA and biliary bilirubin fractions may not exist on some occasions.

Animals↗
PubMed1990

Serum bilirubin fractions in healthy subjects and patients with unconjugated hyperbilirubinemia.

Serum bilirubin fractions were determined by a newly developed, high performance liquid chromatography method in 23 healthy subjects, and in 15 patients with Gilbert's syndrome, five with type 2 Crigler-Najjar syndrome, seven with hemolytic disorders, and 26 with neonatal jaundice. In the healthy subjects, 92.6% of the bilirubin was unconjugated (UCB), 6.2% was bilirubin monoglucoronide (BMG), and 0.5% was bilirubin diglucuronide (BDG). Delta bilirubin (B delta) was not detected. In the patients, the percentage of UCB was significantly higher and that of BMG was significantly lower than in the healthy subjects. The proportion of BDG tended to decrease in Gilbert's and type 2 Crigler-Najjar syndromes; the proportion of B delta tended to increase in hyperbilirubinemia, except in Gilbert's syndrome. In particular, B delta was frequently detected in serum which also contained BDG (mainly in hemolytic disorders) or which presented with high concentrations (above 100 mumol/L) of UCB (mainly in type 2 Crigler-Najjar syndrome and neonatal jaundice). Trace amounts of (Z,E)- and/or (E,Z)-UCB were detected in approximately one fourth of the serum samples analyzed.

Bilirubin↗
PubMed1990

Hepatic uptake of bilirubin diglucuronide: analysis by using sinusoidal plasma membrane vesicles.

In order to characterize the mechanism for bilirubin transport in the liver, the uptake of bilirubin diglucuronide (BDG) into purified sinusoidal plasma membrane vesicles was investigated. BDG uptake was saturable, and was inhibited by sulfobromophthalein and unconjugated bilirubin, but was not affected by sodium taurocholate. BDG uptake was sodium-independent and was stimulated by intravesicular bilirubin or BDG (trans-stimulation). BDG transport showed strong potential sensitivity; vesicle inside-negative membrane potential created by different anion gradients inhibited BDG uptake whereas vesicle inside-positive membrane potential generated by potassium gradients and valinomycin markedly stimulated BDG transport. These data suggest that BDG, sulfobromophthalein, and probably unconjugated bilirubin share a common transporter in liver cells which is sodium independent, membrane-potential-dependent and capable of exchange. The direction of transport in vivo may be governed by the intracellular concentration of BDG and of other yet unidentified organic anions sharing this transporter.

Animals↗
PubMed1990

Diarrhea induced by Treponema hyodysenteriae: a young chick cecal model for swine dysentery.

The experimental infection of 25 young chicks with Treponema hyodysenteriae was carried out. Treponemes were isolated from 21 of 25 chicks on day 21 after inoculation. The ceca of chicks infected with treponemes were atrophied. The lumen was filled with a white watery fluid instead of digested feed. In some infected chicks, a cecal core was observed with the fluid in the cecum. The cecal core was grayish, hard, and rod shaped. It consisted of eroded cells and debris of treponemes and resembled the pseudomembrane. Bloody mucus was also observed in one chick. The thickness of the mucosae in 17 of 25 chicks were markedly increased. The histological changes were classified into two types. In the case of regressive changes of epithelial cells which mean severe erosion, the laminae propriae were exposed. Hemorrhage, edema, and heterophil infiltration in the laminae propriae were also confirmed. Numerous treponemes were observed within the edematous area under the remaining epithelia and also invaded the epithelial cells and laminae propriae. In the other case, progressive changes, that is, hyperplasia of mucosal epithelial cells and elongation of the crypt, were observed. The epithelia consisted mainly of cuboidal basophilic cells, mitotic cells, and goblet cells. The mitotic cells increased in number and were also observed near the superficial luminal surface of the ceca. Mucous goblet cells were also considerably increased in number. The erosion of superficial luminal epithelial cells was not so severe, but edema in laminae propriae was frequently observed. Electron-microscopic observation demonstrated that the basophilic epithelial cells were polyribosome rich, mitochondria poor, and lipid droplet poor. Furthermore, tonofibril-like structures under the terminal web in cytoplasms were lost, and numerous membrane-bound vesicles at the terminal web with free ribosomes were observed. In places, a number of vesicles were observed between microvilli, and some vesicles were released from the apical cytoplasm of epithelial cells. Microvilli also became scarce and irregular. The junctional complexes between cuboidal cells became unclear, the interdigitations between cuboidal cells became loose, and the intercellular spaces were widened. In conclusion, the appearance of numerous membrane-bound vesicles at the terminal web and the dilated intercellular space indicates increased secretion of water and electrolytes, and the abnormal proliferation of such immature epithelial cells indicates impaired absorption. On the basis of our findings, we can say that diarrhea induced by T. hyodysenteriae can be developed by synergism between impaired absorption and increased secretion by intestinal mucosae with hyperplastic immature epithelial cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Change of biological activities of (1----3)-beta-D-glucan from Grifola frondosa upon molecular weight reduction by heat treatment.

Changes of biological activities manifested by (1----6)-branched (1----3)-beta-D-glucans of various molecular weights obtained by heat treatment of the corresponding intact beta-glucan at 150 degrees C (HD-LE) were examined. The activities assessed in this study were as follows: an antitumor activity, activation of alternative complement pathway, glucose consumption by macrophages, macrophage-mediated lysosomal enzyme activity in culture supernatant and cell lysate, interleukin-1 (IL-1) activity, and adjuvant activity. HD-LE could be classified into three groups: 1) HD-LE 0 h (MW 800000) which activated all of the biological activities tested, 2) HD-LE 0.5 and 3 h (MW 250000 and 21000) which lacked or exhibited low levels of activities such as activation of alternative complement pathway and lysosomal enzyme secretion, 3) HD-LE 6 h (MW 6400) which only activated glucose consumption and synthesis of lysosomal enzyme. These results suggest that an antitumor glucan is not always a multiple enhancer of host defense mechanisms and that a large molecular weight is required to augment multiple immunological activities.

Animals↗
PubMed1990

Macrophage activation in vitro by chemically cross-linked (1----3)-beta-D-glucans.

The chemical cross-linking of soluble (1----3)-beta-D-glucans having molecular weights of 21000 (CL 3 h) and 6400 (CL 6 h), and laminarin (CL LAMI), which showed negligible biological activity, by epichlorohydrin provided rigid particles. These particles showed no gel-to-sol transition upon the addition of sodium hydroxide. We compared the effects of chemical cross-linking on the biological activities of glucans. The alternative complement pathway was not activated by any of the cross-linked glucans. Glucose consumption, lysosomal enzyme release, and interleukin-1 production by mouse resident peritoneal macrophages incubated in vitro were strongly induced by CL 3 h, CL 6 h and CL LAMI. However, cross-linked dextran, Sephadex, did not exhibit any of these biological activities. These results suggested that chemical cross-linking of (1----3)-beta-D-glucans enhances macrophage activities without opsonization by complement components.

Animals↗
PubMed1990

[A study on sex chromosome mosaicism--endocrinological and immunohistochemical findings with glutathion S-transferase in the gonads].

In order to clarify the clinical aspects of sex chromosomal mosaicism, we evaluated the karyotypes, the anatomy of external genitalia and internal ductal system, the pituitary-gonadal function, and the histopathology of the gonads by immuno-staining for glutathion S-transferase (GST) in 5 patients who had been all raised as female. Three patients have the 45, X/46, XYq- karyotype in the initial lymphocyte culture or the subsequent culture of skin fibroblasts. Another two karyotypes were 45, X/46, XYq-/47, XYq-, Yq- and 45, X/46, XdicY. Thus, Y chromosome of all patients retained short arms in which the testis determining factor is encoded. Three prepubertal patients were referred to us for their ambigious external genitalia and two postpubertal patients were for the short statures. Although the vaginal orifice was separated from the urethral meatus in all of them, the phallic enlargement was noted in 4 patients and the posterior labial fusion in 2 patients. The oldest patient had a normal female appearance of external genitalia except the vaginal septum. Serum gonadotrophin (GnH) levels were basically high in the postopubertal patients and the responses of GnH to LH-RH were significantly increased in the prepubertal patients. Serum testosterone levels to hCG stimulation ranged from no response to low normal response. All patients underwent the exploratory laparotomy together with the feminizing genitoplasty. The gonads in 3 patients, diagnosed as mixed gonadal dysgenesis (MGD), consisted of a unilateral testis and a contralateral streak gonad. Two patients had variants, including one with bilateral dysgenetic testis and another with bilateral streak gonads.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Terminal differentiation to mature neutrophils and eosinophils in suspension culture of the blast progenitors in acute myeloblastic leukemia.

The blasts obtained from three freshly diagnosed acute myeloblastic leukemia (AML) patients were cultured in suspension to determine whether leukemic blast progenitors can indeed differentiate to form mature granulocytes. One patient was AML M2. The other two patients were bilineal and biphenotypic leukemia, respectively. Media conditioned by human bladder carcinoma line 5637 (5637-CM) or recombinant human granulocyte colony-stimulating factor (rhG-CSF) was added to stimulate growth. In suspension, clonogenic cells grew for 1-3 weeks in two patients, while they did not increase in one patient. After repeated subculture, cells of blast morphology decreased in percentage and polymorphonuclear neutrophils, eosinophils, and monocyte-macrophages appeared. Lymphoid cell component of the patient 2, who was diagnosed as bilineal leukemia by dual-color immunofluorescence analysis, decreased in number after suspension culture and cells of myeloid phenotype became dominant. The findings show that clonogenic blast progenitors can renew themselves and can also undergo terminal differentiation to mature end cells.

Adult↗
PubMed1990

Possible involvement of calpain in down-regulation of protein kinase C.

Calpain is known to play a variety of cellular functions in various cells by Ca2(+)-dependent limited proteolysis. Protein kinase C (PK-C) is a key enzyme in signal transduction. It is known that treatment of a cell with 12-0-tetradecanoylphorbol 13-acetate (TPA) causes down-regulation of PK-C, and that calpain can cleave PK-C into catalytic and regulatory fragments in vitro. In vivo involvement of calpain in down-regulation of PK-C was studied with neuroblastoma cells using various drugs, a synthetic peptide fragment of calpastatin and inhibitors against calpain. TPA-dependent down-regulation of PK-C was partially inhibited by pre-treatment with calpastatin peptide and inhibitors, suggesting in vivo involvement of calpain in down-regulation of PK-C during signal transduction.

Amino Acid Sequence↗