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Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 685 records · Page 38Linked to original sources
PubMed1989

Effects of Ca2+ and Zn2+ on trifluoperazine-S100 proteins interactions: induced circular dichroism and fluorescence spectra.

Interactions of trifluoperazine (TFP) with S100 proteins, EF-hand type Ca2+-binding proteins, in the presence of Ca2+ and Zn2+ were studied with induced circular dichroism (CD) and fluorescence spectra. The positive CD bands of TFP were induced at around 265 nm by adding either S100a or S100a0 protein in the presence of Ca2+. No CD band of TFP was, however, induced by adding S100b protein in the presence of Ca2+. Addition of Zn2+ to the TFP/S100 protein solutions did not induce any CD band at all. The fluorescence intensity of 2-p-toluidinylnaphthalene 6-sulfonate (TNS) bound to S100a or S100a0 protein decreased by adding TFP in the presence of Ca2+, while that bound to S100b protein decreased by adding TFP in the presence of Zn2+, indicating that TFP binds to S100a protein and S100a0 protein in a Ca2+-dependent manner and to S100b protein in a Zn2+-dependent manner. From these results together with other experimental findings it was suggested that (1) TFP binds to S100a protein and S100a0 protein in the presence of Ca2+, with half-saturation points of 18 and 3 microM, respectively, (2) TFP binds to S100b protein only in the presence of Zn2+, (3) alpha-subunit of S100 protein binds to TFP specifically in a Ca2+-dependent manner and beta-subunit in a Zn2+-dependent manner.

Animals↗
PubMed1989

[Basic studies on oral administration of lentinan (I)--influence on lymphocyte subsets in peripheral venous blood].

The effect of oral administration of lentinan (LTN), a biological response modifier, in the control of systemic immune function was studied in 6-week old male Wistar-Imamichi SPF rats. In the LTN group, 1 mg LTN dissolved in 1 ml physiological saline was administration forcibly into the stomach twice weekly. Physiological saline alone was administered in a similar fashion to the control group. Blood samples were obtained prior to and after four and eight weeks of administration. White blood cells and lymphocyte counts were obtained and lymphocyte subsets were measured using monoclonal antibodies W3/13, W3/25 and 0 X 8 (Sera-Lab), and a laser flow cytometry system (Orthospectrum III, Orthodiagnostic System). The T cell ratio, helper/inducer T (Th) cell ratio, and suppressor/cytotoxic T (Ts) cell ratio were measured. The peripheral white blood cell count and lymphocyte count were not significantly different between the control and LTN groups. After four weeks of LTN administration, however, the LTN group showed a significantly higher T cell ratio, Th cell ratio and Th/Ts cell ratio than did the control group, and the Ts cell ratio was significantly lower. In the groups undergoing administration for eight weeks, no difference was noted in the lymphocyte subsets between the two groups. Oral administration of LTN apparently modulates the systemic immune function through T cell stimulation, especially Th cells, but continued administration may induce a tolerance to the effect of LTN.

Administration, Oral↗
PubMed1989

P2-purinergic agonists activate phospholipase C in a guanine nucleotide- and Ca2+-dependent manner in FRTL-5 thyroid cell membranes.

Various adenine nucleotides activated phospholipase C of FRTL-5 cell membranes in the following order of activity, ATP gamma S greater than ATP greater than AppNp greater than AppCp = ADP greater than MeSATP. This order was well consistent with that observed in intact cells. Such activation occurred only in the presence of appropriate concentrations of GTP gamma S and Ca2+, in a way similar to the norepinephrine-induced activation. NaF, a non-specific GTP-binding protein (G-protein) activator, also stimulated the enzyme. These adenine nucleotides, norepinephrine and NaF-induced activations were inhibited by GDP beta S. We conclude that a G-protein is involved in the adenine nucleotides-induced activation of phospholipase C via P2-purinergic receptor in FRTL-5 cells.

Adenylyl Imidodiphosphate↗
PubMed1989

A permissive role of pertussis toxin substrate G-protein in P2-purinergic stimulation of phosphoinositide turnover and arachidonate release in FRTL-5 thyroid cells. Cooperative mechanism of signal transduction systems.

Extracellular ATP and other purinergic agonists were found to inhibit cAMP accumulation by depressing adenylate cyclase as an "inhibitory action" and/or to stimulate arachidonate release in association with phospholipase C or A2 activation and Ca2+ mobilization as "stimulatory actions" in FRTL-5 cells. The stimulatory actions of a group of P2-agonists represented by ATP were partially inhibited by the pretreatment of the cells with islet-activating protein (IAP), pertussis toxin, even when an about 41-kDa membrane protein(s) was completely ADP-ribosylated. Only the IAP-sensitive part of the stimulatory actions was antagonized by 1,3-diethyl-8-phenylxanthine (DPX), an adenosine antagonist. GTP and 8-bromoadenosine 5'-triphosphate (Br-ATP) at two to three orders of higher concentrations than ATP also exerted the stimulatory actions, although they were entirely insensitive to both IAP and DPX. Ligand binding experiments with, [35S]ATP gamma S and [3H]DPX showed that ATP occupies both DPX-sensitive and insensitive receptor sites, whereas GTP does only ATP-displaceable DPX-insensitive sites. Thus, lack of sensitivity of GTP action to DPX was associated with its inability to occupy the DPX-sensitive sites. Adenosine 5'-O-(1-thiotriphosphate) (ATP alpha S), adenosine 5'-O-(2-thiodiphosphate) (ADP beta S) and P1-agonists such as AMP and N6-(L-2-phenylisopropyl-adenosine (PIA) did not show any stimulatory action. Nevertheless, the agonists remarkably enhanced the stimulatory actions of GTP or Br-ATP. Such permissive actions of PIA and others were sensitive to both IAP and DPX, as were shown for a part of the stimulatory actions of ATP as well as the "inhibitory actions" of both PIA and ATP. We conclude that an IAP substrate G-protein(s) which mediates the inhibitory action of purinergic agonists via a DPX-sensitive purinergic receptor(s) may not directly link to the phospholipase C or A2 system but enhance the system which links to a DPX-insensitive P2-receptor, in an indirect or permissive manner.

Adenosine Diphosphate↗
PubMed1989

Isolation and characterization of hagfish thyroid iodoprotein by its non-thyroglobulin nature, very high iodine and carbohydrate contents and low hormone/iodine ratio.

We have characterized the thyroid iodoprotein of a hagfish, Eptatretus burgeri, one of the lowest marine vertebrates. The iodoprotein was not very homogeneous in its apparent molecular mass which decreased with the increase in hormone/iodotyrosine ratio. Four subfractions with an apparent molecular mass of about 400 kDa were purified from one major fraction by size-exclusion and Mono Q ion-exchange HPLC. The subfractions appeared to have the same peptide backbone, since they showed a single band with the same mobility as a 160-kDa protein in SDS/PAGE and the same amino acid composition. However they differed from each other in having increasing iodine contents (1.9% to 5.9% by mass of total amino acids) associated with the increase in hormonal iodine proportion (8.4% to 16.7% of total iodine) and carbohydrate content (35.6% to 53.5% by mass). These values are strikingly different from those of thyroglobulin with an iodine content of less than 1%, hormonal iodine of 20-40% and carbohydrate content of less than 10%. The amino acid composition of the hagfish iodoprotein, especially the cysteine content of less than 1%, was also entirely different from that of thyroglobulin. These results suggest that most, if not all, tyrosine residues of the hagfish thyroid glycoprotein with a less rigid structure are susceptible to an iodinating system, but hormone residues are formed by a much less efficient mechanism than those in thyroglobulin, when poorly iodinated.

Amino Acids↗
PubMed1989

Stimulation of adenosine receptor enhances alpha 1-adrenergic receptor-mediated activation of phospholipase C and Ca2+ mobilization in a pertussis toxin-sensitive manner in FRTL-5 thyroid cells.

Norepinephrine (NE) stimulated FRTL-5 thyroid cells via an alpha 1-adrenergic receptor, resulting in cytosolic Ca2+ [( Ca2+]i) mobilization and activation of phospholipase C. Adenosine and its receptor agonist, phenylisopropyladenosine (PIA), although not exerting a direct effect, markedly enhanced the NE-induced changes. Basal NE action was not totally abolished whereas the permissive action of adenosine and PIA was completely abolished by pretreatment of the cells with islet-activating protein (IAP), pertussis toxin. The decrease in cAMP level induced by adenosine or PIA is not the cause of their permissive effect, since the effect was not reversed by the addition of cAMP-increasing agents. We conclude that an IAP substrate GTP-binding protein(s) plays a novel role in forming a stimulatory coupling between an adenosine receptor and an alpha 1-adrenergic receptor-coupled phospholipase C system.

Adenosine↗
PubMed1989

A pertussis toxin-sensitive GTP-binding protein plays a role in the G0-G1 transition of rat hepatocytes following establishment in primary culture.

Acute spontaneous c-myc gene expression and sustained increase of a GTP-binding protein(s) (G-protein) which is sensitive to islet-activating protein (IAP), pertussis toxin, occurred early during primary culture of adult rat hepatocytes. Following these earlier events, DNA synthesis was demonstrated in response to EGF and insulin. Addition of IAP immediately after plating of primary cultures inhibited c-myc expression and the hormone-induced DNA synthesis. Addition at 24 h or later following cell inoculation, however, produced only weak effects on DNA synthesis, even though the IAP-sensitive G-proteins were completely inactivated. We conclude that the IAP-sensitive G-protein(s) plays a role in the earlier process(es) of the G0-G1 transition, which is essential for the initiation of growth factor-dependent DNA synthesis.

Adenosine Diphosphate Ribose↗
PubMed1989

Biopsy diagnosis of well-differentiated hepatocellular carcinoma based on new morphologic criteria.

Nodular hepatic lesions detected in 123 patients with chronic liver diseases were subjected to ultrasonically guided needle biopsy. Of these, 94 cases were diagnosed as hepatocellular carcinoma of a moderately or poorly differentiated type with classical histologic features of hepatocellular carcinoma. In 14 cases in whom hepatocytes had minimal atypical changes and were mostly of normotrabecular arrangement (one to two cells thick), a diagnosis of well-differentiated hepatocellular carcinoma was made on the basis of the following three histologic criteria: nuclear crowding, increased cytoplasmic basophilia and microacinar formation. The nodules which showed two or more of these findings were diagnosed as well-differentiated HCC. The diagnoses of these 14 cases were subsequently confirmed by clinical course, histology in the resected specimen and/or autopsy findings. The nodules that presented similar but equivocal changes were arbitrarily categorized as borderline lesions (five cases). The nodules showing the findings almost identical with those of pseudolobules were regarded as benign, large regenerative nodules (nine cases). The remaining one case had a hemangioma. Thus, these three histologic criteria proved to be useful in the biopsy diagnosis of nodular hepatic lesions, with certain limitations. Additionally, the majority of large regenerative nodules, borderline lesions and well-differentiated HCCs were found to be smaller than 2 cm.

Biopsy, Needle↗
PubMed1989

A new double-barrelled, ionophore-based microelectrode for chloride ions.

A new Cl- selective microelectrode based on the ionophore 5,10,15,20-tetraphenyl-21H,23H-porphin manganese(III) chloride is presented which discriminates better against HCO3- and several organic anions than electrodes containing the Corning 477913 ion-exchanger. Using a redesigned construction procedure, fine-tip double-barrelled microelectrodes were produced which had slopes of -52.4 +/- 0.6 mV (SE, n = 24), resistances of about 7.10(11) omega and a selectivity coefficient log KpotCLHCO3 of -1.40 +/- 0.03. Some electrodes showed a small unexplained sensitivity to pH greater than 7.6. When used to puncture cells of isolated S3 segments of rabbit renal proximal tubule during perfusion with HCO3- Ringer solution, the electrodes gave a membrane potential of -69.8 +/- 1.5 mV and an intracellular Cl- activity, [Cl-]i, of 35.3 +/- 2.6 mmol/l. Upon switching bath and lumen perfusions to Cl- -free solutions the "residual" [Cl-]i dropped to 1.20 +/- 0.03 mmol/l, while in similar measurements with ion-exchanger electrodes the "residual" [Cl-]i dropped only to 10.9 +/- 0.5 mmol/l. These observations demonstrate the superiority of the new electrode and prove that previously determined high [Cl-]i values in Cl- -free ambient solutions reflect interference problems rather than non-exchangeable intracellular chloride.

Animals↗
PubMed1989

Mucinous cystadenocarcinoma of the colon. Report of a case.

A rare case of mucinous cystadenocarcinoma arising in the sigmoid colon, found accidentally during an operation for cholecystolithiasis, is reported. The tumor was located 40 cm from the anal verge, and had two histologic variations consisting of a large distended cystic lesion and branching cystic channels with papillary proliferation of the epithelium. Serial sections revealed the existence of a luminal communication between the two lesions. The tumor tissue was seen mainly in the muscularis propria with no mucosal involvement. The papillary portion had a highly differentiated appearance, giving rise to considerable difficulty in determining whether it was benign or malignant. In a localized area, however, the tumor invaded into the subserosa and showed distinctive atypical changes. The tumor cells showed intense reactivity for carcinoembryonic antigen. This mucinous cystadenocarcinoma was considered to be originated from an enterogenous cyst, a possible derivative of duplication of the colon. The differential diagnosis concerning this rare tumor is also discussed.

Aged↗
PubMed1989

Antigenic determinants of the cytoplasmic domain of band 3 from bovine erythrocyte membrane.

Rabbit antibodies were prepared against the cytoplasmic 38K-Da fragment of bovine band 3 and the immunological cross-reactivity with human, murine, rat, and chicken band 3 was examined. The antibodies cross-reacted with human and rodent band 3, indicating that there is an antigenic determinant(s) common to primate and nonprimate species. However, the antibodies did not recognize chicken band 3. Antigenic sites on the 38K-Da fragment were determined via amino acid sequence and immunoblotting analyses of proteolytic peptides of the fragment. Positions of antigenic determinants which were assumed to be common to primate and nonprimate species were mapped to the areas of residues 127-160 and of residues 259-304 in the primary structure of human band 3. Another epitope(s), which is absent in human band 3, existed in a region having a bovine-specific amino acid sequence. In addition, comparison of sequence data from different species showed that a proposed hinge region and a tryptophan-rich region on the cytoplasmic domain of band 3 [P. S. Low et al. (1984) J. Biol. Chem. 259, 13,070-13,076; R. R. Kopito and H. F. Lodish (1985) Nature (London) 316, 234-238] are also conserved in the bovine case.

Amino Acid Sequence↗
PubMed1989

Hepatocellular carcinoma without cirrhosis in Japanese patients.

Hepatocellular carcinoma is closely associated with cirrhosis, but it also develops, although much less frequently, in a noncirrhotic liver. It is suspected, without supporting evidence, that hepatocellular carcinoma has a different etiology when associated and not associated with chronic liver disease. In this study, 66 noncirrhotic cases found among 618 autopsies for hepatocellular carcinoma (10.7%) were analyzed retrospectively. The noncirrhotic liver was histologically unremarkable in 3 cases and in the histologically evaluable 56 cases it had fibrosis of varying degrees or mild cellular infiltrate, or both, in the portal tract. There was one liver that had portal venous changes compatible with those in idiopathic portal hypertension (Banti's syndrome). In these noncirrhotic livers, the parenchymal cells were generally unremarkable except for liver cell dysplasia that was seen in 26.8%. Serum hepatitis B surface antigen was positive in only 7.4% in contrast to 26.6% in cirrhotic cases. Three histologically unremarkable cases had no clinical or histologic evidence of chronic liver disease; two involved painter-plasterers and one a farmer. The liver weight in these cases ranged from 4400 to 6180 g. In contrast, the average liver weight in cirrhotic cases was 1998 g. Noncirrhotic patients when compared with cirrhotic patients had better liver function tests and much less frequent varices. It was concluded that approximately 11% of hepatocellular carcinoma cases in Japan are noncirrhotic, the majority having some histologic changes in the portal tracts suggestive of past or ongoing chronic liver disease, and that there are rare cases that have no histologic changes in the liver.

Adult↗
PubMed1989

Micronucleus test with vincristine administered by intraperitoneal injection and oral gavage.

The effects of vincristine sulfate (VINC) on micronucleus induction were studied in 2 strains of mice (MS/Ae: CD-1) following intraperitoneal (i.p.) or oral administration (p.o.) of the chemical. On the basis of a small-scale acute toxicity study and a pilot micronucleus experiment, the full-scale micronucleus test was performed with a sampling time of 24 h at doses of 0.063, 0.125, 0.25 and 0.5 mg/kg (i.p.) and 1.25, 2.5, 5.0 and 10 mg/kg (p.o.). The maximum frequency of micronucleated polychromatic erythrocytes was 7.15% in MS/Ae mice and 4.98% in CD-1 mice at 5.0 mg/kg p.o. in both cases. The maximum frequencies by the i.p. route (9.93% in MS/Ae mice; 11.68% in CD-1 mice) occurred at 0.25 mg/kg and 0.125 mg/kg, respectively. Although the doses showing a positive response were different between the 2 routes, VINC induced micronuclei very efficiently at all doses tested by both administration routes in both strains.

Administration, Oral↗
PubMed1989

Inhibitory effects of poly(L-aspartic acid) on the assembly of brain microtubules and the interaction of microtubule-associated protein 2 with F-actin in vitro.

The effects of poly(L-aspartic acid) (PLAA) on microtubule assembly and microtubule-associated protein (MAP) 2-actin interaction were examined in vitro. PLAA inhibited assembly of rat brain microtubules and induced rapid disassembly of already formed microtubules. Inhibition was stronger by PLAA with a high molecular weight than that by low molecular weight. The ratios of 47 kDa PLAA to microtubule proteins causing 50% inhibition of the assembly and disassembly were 0.015 and 0.04 (w/w), respectively. Both MAP 1 and MAP 2 were bound to a PLAA-Sepharose 4B affinity column, while tubulin was not retained by the column. PLAA caused selective dissociation of MAP 1 and MAP 2 from microtubules polymerized by taxol. It is therefore concluded that PLAA interacts specifically with MAPs. PLAA also inhibited the MAP 2 induced cross-linking of actin filaments, showing an almost complete inhibition at a PLAA to MAP 2 ratio of 1:5,000 (w/w). Binding experiments of PLAA with digested MAP 2 by chymotrypsin using affinity chromatography and sedimentation experiments showed that PLAA was preferentially bound to a 35 kDa fragment which includes the microtubule- and actin-binding domain of the MAP 2 molecule. These results suggest that PLAA suppressed the functions of MAP 2 through a domain which is located in the 35 kDa fragment.

Actins↗
PubMed1989

Characterization of copper atoms in bilirubin oxidase by spectroscopic analyses.

Bilirubin oxidase [EC 1.3.3.5], purified from the culture medium of Myrothecium verrucaria, was found to contain two blue copper atoms per protein molecule with a molecular weight of ca. 52 kDa. The two copper atoms were estimated to be in the all cupric state by the cuproine colorimetric method and also atomic absorption analysis. We could remove the reduce cuprous ions from the holo enzyme by adding ascorbate, followed by a KCN solution, yielding an apo-enzyme with no activity. The apo-enzyme can be reconstituted with Cu or other divalent cations such as Co, Fe, and Cd, with accompanying recovery of the enzyme activity. The activity recovery depended upon the species of cation employed; Cu being most effective, an almost 100% recovery, and Cd the least, only a 25% recovery. We could obtain information on the copper ions and their coordination structure by spectroscopic analyses of the apo- and reconstituted enzymes, obtaining such as absorption, CD, MCD, and XPS spectra. The bilirubin oxidase catalyzed-reaction was a second order reaction with respect to copper bound with protein. The donor set was of the CuSS*N2 (S = Cys, S* = Met, N = His) type, i.e., the same as in the case of blue copper proteins. On studying the Co-substituted enzyme, it was revealed that the copper site of the enzyme had a 4-coordinated structure.

Apoproteins↗
PubMed1989

Peliosis hepatis. An unusual case involving the spleen and lymph nodes.

A case of peliosis hepatis in a 52-year-old woman with unusual involvement of the spleen and lymph nodes is described. The initial sign was intraperitoneal hemorrhage from the splenic lesion, recessitating splenectomy. The hepatic lesion, which was first noticed during the operation, rapidly progressed and eventually resulted in hepatic rupture with fatal intraperitoneal hemorrhage. Serial sections treated by silver impregnation revealed degeneration and dissolution of the fine reticulin framework in the involved organs, suggesting the possible morphogenesis of the peliotic lesion. The patient had no history of any underlying disorders or of medication with steroids.

Female↗
PubMed1989

Requirement of insulin growth factor I plus hydrocortisone for the regeneration of thyrotropin (TSH)-dependent mechanism of I-efflux and Ca2+ mobilization in FRTL-5 cells during TSH depletion.

FRTL-5 rat thyroid cells grown in culture medium supplemented with serum and 6H (TSH, insulin, hydrocortisone, transferrin, glycylhistidyllysine, and somatostatin) showed a significant increase in TSH-dependent cAMP accumulation and I- efflux after prolonged incubation (5 to 10 days) of the cells in culture medium containing 5H (6H - TSH) or serum. The induction of the cAMP response was at least partly reproduced when both serum and 5H were omitted from the medium. However the I- efflux response was completely abolished under such conditions and regenerated when serum or 5H was present. The serum or 5H effect on I- efflux response was mimicked by 2H (insulin + hydrocortisone). Insulin was replaced by 1/1000 less insulin-like growth factor-I than insulin. TSH-dependent Ca2+ mobilization of the cells was similarly affected by the presence of serum or 2H. However, the I- efflux and Ca2+ responses to an agonist other than TSH (extracellular ATP) were not substantially influenced by serum and/or 2H as well as TSH in the medium. The results indicate that serum or insulin-like growth factor-I plus hydrocortisone are required rather specifically for the regeneration of the TSH-receptor mechanism coupled with I- efflux and/or Ca2+ mobilization mechanism.

Animals↗