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Y Kondo

Publications and source records attributed to Y Kondo.

At least 649 records · Page 36Linked to original sources
PubMed1990

Inhibition of atrial natriuretic peptide-induced cGMP accumulation by purinergic agonists in FRTL-5 thyroid cells. Involvement of both pertussis toxin-sensitive and insensitive mechanisms.

Extracellular ATP, N6-(L-2-phenylisopropyl)adenosine (PIA) and other purinergic agonists inhibited atrial natriuretic peptide (ANP)-induced cGMP accumulation in FRTL-5 thyroid cells. These agonists were functionally classified into three groups. Group 1 agonists represented by ATP inhibited the ANP action in association with phospholipase C activation in a partially islet-activating protein (IAP, pertussis toxin)-sensitive manner. Group 2 including GTP and 8-bromoadenosine 5'-triphosphate acted similarly to Group 1 except for total insensitivity of the former to IAP. The IAP-insensitive portion of Group 1 actions and the actions of Group 2 as well as of A23187, a Ca2+ ionophore which mimicked the Group 2 agonist actions, were almost completely inhibited by phosphodiesterase inhibitors such as M & B 22948 (2-O-propoxyphenyl-8-azapurin-6-one) and 3-isobutyl-1-methylxanthine. Group 3 including PIA and AMP did not affect phospholipase C, but inhibited the ANP performance in an IAP-sensitive fashion. This action of Group 3 and the IAP-sensitive portion of Group 1 actions were insensitive to the phosphodiesterase inhibitors. We conclude that ATP and other Group 1 agonists attenuated the ANP-induced cGMP accumulation by at least two mechanisms: 1) stimulation of cGMP hydrolysis via a phospholipase C-Ca2(+)-phosphodiesterase system and 2) inhibition of cGMP generation, probably by an IAP-sensitive G-protein-mediated inactivation of the ANP-receptor-coupled guanylate cyclase. Group 2 agonists stimulate only the first mechanisms, whereas Group 3 agonists prefer the second one.

Adenosine Deaminase↗
PubMed1990

Role of Ca2+/phospholipid-dependent protein kinase in catecholamine secretion from bovine adrenal medullary chromaffin cells.

The role of Ca2+/phospholipid-dependent protein kinase (protein kinase C) in catecholamine secretion from bovine adrenal medullary chromaffin cells was examined using four protein kinase C inhibitors: polymyxin B, sphingosine, staurosporine, and 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7). For this purpose, digitonin-permeabilized chromaffin cells were used. Secretion of catecholamines from these cells was stimulated by the addition of micromolar amounts of exogenous free Ca2+. 12-O-Tetradecanoylphorbol-13-acetate (TPA) and arachidonic acid, activators of protein kinase C, enhanced the catecholamine secretion evoked by Ca2+. But phorbol-12, 13-diacetate, a phorbol ester analog that does not activate protein kinase C, had no effect on Ca2(+)-evoked secretion. Polymyxin B at a low concentration (1 microM) abolished the enhancement of secretion by TPA or arachidonic acid without affecting the secretion evoked by Ca2+. However, polymyxin B at higher concentrations (10-100 microM) greatly reduced Ca2+-evoked catecholamine secretion. Sphingosine 10 microM-1 mM), Staurosporine (100 nM-1 microM, and H-7 (100-500 microM) inhibited TPA- or arachidonic acid-enhanced secretion but not Ca2(+)-evoked secretion. In cells in which protein kinase C was down-regulated by TPA, specific binding of [3H]phorbol-12,13-dibutyrate to the cells almost disappeared and the enhancement of secretion by TPA was no longer observed, whereas Ca2(+)-evoked secretion was maintained. These results strongly suggest that protein kinase C is not essential for the Ca2(+)-dependent catecholamine secretion from bovine adrenal chromaffin cells, but acts instead as a modulator.

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

Separation of DNA fragments by high-resolution ion-exchange chromatography on a nonporous QA column.

A nonporous QA column (a strong anion exchanger) was used for HPLC of DNA fragments. This column was successfully employed to separate small (ca. 10 bp) and intermediate size (ca. 10 kbp) DNA fragments from each other. The column also separated double-stranded DNA from its single-stranded form, and circular DNA molecules from linear ones. The entire separation process was completed within 60 min. The recovery of DNA fragments in each run was above 95%. High resolution was obtained both at an analytical level (microgram scale) and at a preparative level (100 micrograms scale). In view of time efficiency, recovery, and resolution, the nonporous QA column is superior to other porous ion-exchange columns and expected to be a very useful tool in molecular biological studies.

Anions↗
PubMed1990

[Recurrence of endometrial cancer and its pathological factors].

The number of patients with uterine endometrial cancer has increased in recent years in Japan. The studies on the prognostic factors of endometrial cancer, however, have not been made in detail as compared with those on the prognostic factors of cervical cancers. We have therefore investigated retrospectively the prognoses of 94 cases with endometrial cancer treated in our clinic from 1973 to 1984. Out of 31 cases (32.9%) with recurrence, 13 cases were at the Stage I and II, and the recurrence ratios were 11.4% for Stage Ia, 18.2% for Stage Ib and 31.3% for Stage II. The prognosis of endometrial carcinoma appears to depend on the endocervical involvement of the cancer. Five prognostic factors for Stage I and II endometrial cancers analyzed here are as follows; (1) histologic differentiation (grade), (2) size (diameter) of the primary tumor, (3) myometrial invasion, (4) vascular invasion, (5) lymphnode metastasis. (1) The recurrence ratio was 15.0% in the well differentiated (Grade 1) group, 25.0% in the moderately differentiated (Grade 2) group, 27.3% in the poorly differentiated (Grade 3) group, and 12.5% in adenoacanthoma. (2) The ratio of recurrence was 2.9% with less than 3 cm diameter, 24% with 3-6 cm diameter, and 30% with greater than 6 cm diameter in tumor size. (3) The ratio of recurrence was 2.9% with less than 1/3, 24% with 1/3-2/3, and 30% with greater than 2/3 myometrial invasion. (4) The ratio of recurrence was 43.8% with vascular invasion, and 5.6% without it. (5) The ratio of recurrence was 75% with lymphnode metastasis, and 8.8% without it.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1990

The center for controlling the near reflex in the midbrain of the monkey: a double labelling study.

The center for controlling the near reflex was studied in the midbrain of the monkey using Diamidino yellow dihydrochloride (DY) and Fast blue (FB) as retrograde neuronal tracers. After injection of DY into the ciliary ganglion, many labelled neurons were found ipsilaterally in the anteromedian nucleus, the Edinger-Westphal nucleus, and the nucleus of Perlia. In contrast, after injection of FB into the medial rectus muscle, labelled cells were found ipsilaterally only in the Edinger-Westphal nucleus of the visceral nuclei as well as in the somatic ipsilateral nuclei. No double labelling of cells was noted in the Edinger-Westphal nucleus, establishing the premise that FB-labelled cells were subserving medial rectus muscle and pupillary/accommodative functions and DY cells were subserving pupillary/accommodative functions independently.

Amidines↗
PubMed1990

Location of dehydroalanine residues in the amino acid sequence of bovine thyroglobulin. Identification of "donor" tyrosine sites for hormonogenesis in thyroglobulin.

Thyroid hormonogenesis in thyroglobulin results in the conversion of an "acceptor" iodotyrosine to a hormone residue and a "donor" iodotyrosine to a dehydroalanine residue. Altogether five acceptor sites have been located as hormone residues in thyroglobulin of different animal species. To search for donor sites, we treated bovine thyroglobulin with 4-aminothiophenol to specifically modify dehydroalanine residues to S-(4-aminophenyl)cysteine (APC) residues, according to the principle of dehydroalanine determination developed by us (Kondo, T., Kondo, Y., and Ui, N. (1988) Mol. Cell. Endocr. 57, 101-106). After digesting thyroglobulin with lysyl endopeptidase, APC-containing peptides were separated from other peptides by trapping them on immobilized naphthylethylenediamine and from each other by size-exclusion and reverse-phase high performance liquid chromatography (HPLC). The HPLC patterns showed about 10 APC-containing peptides. Among them, four different peptides were purified by repeated reverse-phase HPLC. The results of partial sequencing of the four peptides by manual Edman degradation disclosed that Tyr5, Tyr926, Tyr1375, and Tyr986 or Tyr1008 are available for hormonogenesis as donor sites. These results strongly suggest that only specific tyrosine residues behave as donors.

Alanine↗
PubMed1990

A clinicopathologic study of intrahepatic cholangiocarcinoma containing a component of squamous cell carcinoma.

Eleven cases of cholangiocarcinoma containing a component of squamous cell carcinoma (CC-SCC) were reviewed clinicopathologically in comparison with 82 cases of common cholangiocarcinoma presenting as a pure form of adenocarcinoma (CC-AC). The former type was prone to develop in a rather advanced stage of the disease, as indicated by short survival time, large tumor size, aggressive modes of intrahepatic spreading, and frequent metastasis. Histologically, the area of squamous cell carcinoma ranged from focal to overwhelming. The occurrence of the squamous element could be interpreted as the result of the metaplastic transformation of adenocarcinoma cells because of the intimate coexistence of the two types in the primary and metastatic lesions. It also was suggested that anaplastic carcinoma cells could sometimes differentiate into squamous cell carcinoma. In no instances was there any squamous metaplasia of the bile ducts demonstrated; therefore, there was no supporting evidence for the possibility of squamous metaplasia of the bile duct epithelium and subsequent malignant transformation.

Adenocarcinoma↗
PubMed1990

Selective purification of microtubule-associated proteins 1 and 2 from rat brain using poly(L-aspartic acid).

A rapid and selective purification procedure for microtubule-associated protein (MAP) 1 and MAP 2 has been established. This procedure is based upon the fact that poly(L-aspartic acid) (PLAA) can specifically remove MAP 1 from microtubules polymerized by taxol (Nakamura et al., 1989, J. Biochem. 106, 93-97). MAP 1 released by PLAA was further purified by column chromatography on phosphocellulose and Bio-Gel A-15m. The purified MAP 1 contained MAPs 1A and 1 B. From microtubules devoid of MAP 1, MAP 2, consisting of MAPs 2A and 2B, could also be isolated by exposure to high ionic strength solutions in the presence of taxol without heat treatment. Both MAPs 1 and 2 cosedimented with microtubules consisting of purified tubulin.

Alkaloids↗
PubMed1990

Histological features and clinical course of large regenerative nodules: evaluation of their precancerous potentiality.

Seventeen patients with cirrhosis and histologically defined, ultrasonically detected, large regenerative nodules of the liver were followed without treatment for more than 1 yr (range = 13 to 51 mo). During the follow-up period, none of the nodules were demonstrated sonographically to have enlarged. Computed tomography and/or hepatic angiography were also performed in 14 patients, but there was no evidence of malignant transformation in these lesions. None of the 17 patients showed acute elevation of serum alpha-fetoprotein levels. Furthermore, four nodules became undetectable by these imaging procedures. Follow-up biopsy performed in seven patients revealed no significant histological changes from the first biopsy sample. However, HCCs developed apart from these large regenerative nodules in four patients. These HCCs suddenly appeared and did not seem to have been derived from preexisting large regenerative nodules. From these observations, it was not possible to regard a large regenerative nodule having no cytological atypia as a high-potential premalignant lesion. Their precancerous potentiality needs to be compared with that of ordinary pseudolobules.

Angiography↗
PubMed1990

Evidence of chloride/bicarbonate exchange mediating bicarbonate efflux from S3 segments of rabbit renal proximal tubule.

The mechanism of HCO3- exit from rabbit renal proximal tubule S3 segments was investigated. Isolated tubules were perfused luminally and peritubularly with test solutions and cell pH (pHi), cell Cl- activity ([Cl-]i) and cell Na+ activity ([Na+]i) were measured with ion-selective microelectrodes. From the response of pHi and [Cl-]i to changes in bath Cl- or HCO3- concentrations a Cl-/HCO3- exchanger was identified in the basolateral cell membrane. It was reversibly inhibited by millimolar concentrations of the disulfonic stilbene SITS (4-acetamido-4'-isothiocyanato-stilbene-2,2'-disulfonic acid). Cell potential measurements and preliminary determinations of initial ion flux rates suggested a stoichiometry of Cl- to HCO3- flux near 1.0. The transport rate appeared to saturate already at low bath Cl- concentrations (approximately 30 mmol/l), but it was independent of bath pH in the range of 7.4-6.4. Cl-/HCO3- exchange was not directly coupled to Na+ flux although in approximately half of the experiments long-term incubation in Na(+)-free solutions indirectly inhibited the exchanger. Sudden application of SITS under control conditions revealed that the exchanger normally facilitates the exit of HCO3- from cell to interstitium at the expense of Cl- uptake into the cell. How Cl- ions recirculate towards the peritubular surface is presently not known.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1990

Molecular heterogeneity of the subclasses of islet-activating protein (pertussis toxin)-sensitive GTP-binding proteins in porcine thyroid tissue.

From porcine thyroid cell membranes, we purified five GTP-binding proteins (G-proteins); Nos. 1 to 3 have 41-kDa alpha-subunits, and Nos. 4 and 5 have 40-kDa alpha-subunits. They were chromatographically (Mono Q) separable and served as specific substrates for islet-activating protein (pertussis toxin). G-proteins 1 and 2 were indistinguishable from porcine brain Gi1 with respect to three criteria, i.e., mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), pI of the ADP-ribosylated alpha-subunit, and immunoreactivity. G-protein 3 was identified as Gi3 by immunoreactivity. The SDS-PAGE and isoelectric focusing (IEF) analyses identified G-proteins 4 and 5 as being chromatographically heterogeneous subtypes of Gi2 in comparison with a pure porcine brain preparation. The IEF analysis also disclosed that each of the Gi1, Gi2, and Gi3 subspecies isolated in the present study has a minor component characterized by a slightly lower pI of its alpha-subunit. We conclude that porcine thyroid tissue contains at least Gi1, Gi2, and Gi3, and that each is made up of heterogeneous populations.

Animals↗
PubMed1990

A novel water-soluble dopamine-2 antagonist with anticholinesterase activity in gastrointestinal motor activity. Comparison with domperidone and neostigmine.

A novel water-soluble dopamine-2 antagonist, N-[4-[2-(dimethylamino) ethoxy]benzyl]-3,4-dimethoxybenzamide hydrochloride (HSR-803) was synthesized and assayed for its gastrointestinal smooth muscle stimulating activity in vivo and in vitro. In the in vivo study, gastrointestinal contractile activity was measured by means of chronically implanted force transducers in conscious dogs; it was found that HSR-803 at 3.0 mg/kg IV probably stimulated gastric contractile force twice during the digestive state and significantly antagonized dopamine-(1.0 mg/kg per hour) inhibited gastric contractions in doses of 0.3, 1, and 3 mg/kg IV. With a background IV infusion of HSR-803 at 3 mg/kg per hour, the contraction-stimulating activity of acetylcholine (0.05 mg/kg per minute) was greatly enhanced while the response to bethanechol was not changed. As a result, HSR-803 was found to have a strong anticholinesterase activity besides the antidopamine-2 activity; i.e., the anticholinesterase activity of HSR-803 at 3 mg/kg per hour was equivalent to that of neostigmine at 10 micrograms/kg per hour, and dopamine-2 antagonistic activity of HSR-803 was similar to that of domperidone on a weight basis. No symptom suggesting actions on the central nervous system was noticed in HSR-803 up to 10 mg/kg IV in conscious dogs. In the in vitro study, HSR-803 inhibited cholinesterase dose-dependently, and IC50 was 2.9 x 10(-6) mol/L, while those of neostigmine and domperidone were 2.3 x 10(-8) mol/L and 1.7 x 10(-5) mol/L, respectively. In conclusion, HSR-803 stimulates endogenous acetylcholine release by antagonizing the dopamine-2 receptor on the postsynaptic cholinergic neurons, and the anticholinesterase activity of HSR-803 may cause the released acetylcholine to accumulate at cholinergic receptor sites. Thus, HSR-803 is potentially capable of enhancing cholinergic activity in the gastrointestinal region.

Animals↗
PubMed1990

Role of septum and preoptic area in regulating masculine and feminine sexual behavior in male rats.

The effects of septal or preoptic lesions on both masculine and feminine sexual behaviors were examined in castrated adult male rats. Three weeks after brain surgery, animals were implanted with Silastic tubes containing testosterone (T) and observations of masculine sexual behavior were carried out four times every 5 days. T tubes were removed immediately after the end of the masculine behavioral tests. Two weeks later, animals implanted with Silastic tubes containing estradiol-17 beta(E2) were subjected to three feminine sexual behavioral tests at 5-day intervals. The bilateral lateral septal lesion (LSL) and the medial preoptic lesion (MPOL) effectively suppressed the performance of mounts, intromissions, and ejaculations, whereas the medial septal lesion (MSL), the dorsolateral preoptic lesion (DPOL), and the sham operation did not show any significant suppression of these behaviors. In the feminine sexual behavioral tests, intact and sham-operated control males showed only a low lordotic activity. However, the performance of the lordosis reflex was markedly facilitated by LSL or DPOL, while the lordotic activity of MSL and MPOL males was not significantly different from that of control males. These results suggest that the lateral septum exerts not only a facilitatory influence on masculine sexual behavior but also an inhibitory influence on feminine sexual behavior in male rats. On the other hand, the medial preoptic area may play a critical role in regulating masculine sexual behavior in male rats.

Animals↗
PubMed1990

19F-n.m.r. study of trifluoperazine-S100 protein interaction: effects of Ca2+ and Zn2+.

19F-n.m.r. spectra were measured to investigate the effects of Ca2+ and Zn2+ on the interaction of trifluoperazine (TFP) with three S100 proteins. It was found that TFP binds to S100a and S100ao proteins irrespective of the presence of Ca2+ and Zn2+, while in the presence of Ca2+ the apparent affinity of TFP to the proteins was greater than that in its absence or in the presence of Zn2+. In contrast, the binding affinity of TRP to S100b protein in the presence and absence of metal ions was lower than to S100a and S100ao proteins. These results suggested that TFP binds to each S100 protein in two ways: one is Ca2(+)- or Zn2(+)-dependent specific manner and another is Ca2(+)- or Zn2(+)-independent non-specific manner.

Calcium↗
PubMed1990

Evaluation of a reassortant rhesus rotavirus vaccine in young children.

A candidate live attenuated rotavirus vaccine representative of serotype 1 was administered orally to 26 children, 14 of whom were undergoing primary exposure to rotavirus. The vaccine was derived by reassortment between rhesus rotavirus strain, MMU 18006, and the human serotype 1 strain Wa. The resultant virus has the gene coding for the major surface glycoprotein VP-7 from the human strain and all other genes from the attenuated rhesus parent which is a serotype 3 strain. Prior natural exposure to rotavirus determined the infectivity and immunogenicity of the vaccine. Only two of 12 seropositive children had evidence of reinfection while all 14 seronegative children were infected. Mild febrile illness was seen in vaccinees, however there was no evidence of gastrointestinal disease. As determined by neutralization of the human strains, the resultant serum antibody was entirely strain specific. However, heterotypic neutralization was seen when the rhesus strains were used, suggesting that neutralizing antibody can be directed to shared components of the donor and reassortant strain presumably VP-4, the other major surface protein.

Age Factors↗
PubMed1990

Effect of ethanol on fatal carbon monoxide poisoning in awake mice [correction of rats].

The effect of ethanol on fatal carbon monoxide (CO) poisoning was investigated in mice injected intraperitoneally with ethanol. Ethanol (1.5 and 3.0 g/kg) was injected 15 min prior to exposure to gas containing 6.6% CO. The survival period was significantly lengthened with ethanol in proportion to the doses injected, although the carboxyhemoglobin (CO-Hb) saturation level in postmortem blood was almost the same in all groups. On the other hand, the CO-Hb level in the blood of mice injected with ethanol was significantly lower than that of control mice during the early exposure period when all mice were still alive. Our results showed that the acute ethanol injection did not influence the CO-Hb saturation level in blood at death, but did affect the duration of survival, probably because of ethanol's ability to decrease blood flow and CO intake.

Animals↗
PubMed1990

Calcium-dependent control of caldesmon-actin interaction by S100 protein.

Caldesmon from chicken gizzard muscle has been examined for ability to interact with S100 protein using sedimentation, low-shear viscosity, and affinity chromatography. Ca2+/S100 protein, like Ca2+/calmodulin, inhibited the binding of caldesmon to F-actin in a concentration-dependent manner and the inhibition was not observed in the absence of Ca2+. Caldesmon was bound to S100 protein-Sepharose in the presence of Ca2+ and released with EGTA, indicating that there is a direct interaction between caldesmon and S100 protein. The binding of S100 protein to caldesmon also relieved actomyosin Mg2(+)-ATPase inhibition by caldesmon. The molar ratio of S100 protein to caldesmon required for half-maximal restoration was about 0.3, a value less than that in the case of calmodulin. S100 protein, however, was less effective in terms of the maximal extent of the restoration. With respect to Ca2(+)-sensitivity, the restoration profiles were monophasic with a midpoint at 3 x 10(-5) M for S100 protein and 8 x 10(-6) M for calmodulin. The restoration by S100 protein was almost wholly inhibited by TFP, but not by W-7. Taken together, our results suggest that a Ca2(+)-binding protein other than calmodulin may regulate caldesmon-dependent cellular functions.

Actins↗