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T Isono

Publications and source records attributed to T Isono.

At least 19 recordsLinked to original sources
PubMed2002

Increase in intracellular Ca(2+) and calcitonin gene-related peptide release through metabotropic P2Y receptors in rat dorsal root ganglion neurons.

We examined the effects of the activation of metabotropic P2Y receptors on the intracellular Ca(2+) concentration and the release of neuropeptide calcitonin gene-related peptide (CGRP) in isolated adult rat dorsal root ganglion neurons. In small-sized dorsal root ganglion neurons (soma diameter<30 microm) loaded with fura-2, a bath application of ATP (100 microM) evoked an increase in intracellular Ca(2+) concentration, while the removal of extracellular Ca(2+) partly depressed the response to ATP, thus suggesting that the ATP-induced increase in intracellular Ca(2+) concentration is due to both the release of Ca(2+) from intracellular stores and the influx of extracellular Ca(2+). Bath application of uridine 5'-triphosphate (UTP; 100 microM) also caused an increase in intracellular Ca(2+) concentration in small-sized dorsal root ganglion neurons and the P2 receptor antagonists suramin (100 microM) and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS; 10 microM) virtually abolished the response, indicating that the intracellular Ca(2+) elevation in response to UTP is mediated through metabotropic P2Y receptors. This intracellular Ca(2+) increase was abolished by pretreating the neurons with thapsigargin (100 nM), suggesting that the UTP-induced increase in intracellular Ca(2+) is primarily due to the release of Ca(2+) from endoplasmic reticulum Ca(2+) stores. An enzyme-linked immunosorbent assay showed that an application of UTP (100 microM) significantly stimulated the release of CGRP and that suramin (100 microM) totally abolished the response, suggesting that P2Y receptor-mediated increase in intracellular Ca(2+) is accompanied by CGRP release from dorsal root ganglion neurons. These results suggest that metabotropic P2Y receptors contribute to extracellular ATP-induced increase in intracellular Ca(2+) concentration and subsequent release of neuropeptide CGRP in rat dorsal root ganglion neurons.

Adenosine Triphosphate↗
PubMed2001

Immunohistochemical localization of steroidogenic enzymes in the corpus luteum and the placenta of the ribbon seal (Phoca fasciata) and steller sea lion (Eumetopias jubatus).

To study the luteal and placental function of pinnipeds, we analyzed the localization of steroidogenic enzymes (P450scc, 3 beta HSD and P450arom) in the corpus luteum and the placenta of ribbon seals (Phoca fasciata) and Steller sea lions (Eumetopias jubatus) immunohistochemically. P450scc and 3 beta HSD were present in all luteal cells of both species. Almost all of the luteal cells were immunostained for P450arom, while P450scc and 3 beta HSD were negatively immunostained in placentae and P450arom was present in the syncytiotrophoblast of placentae. These findings suggest that 1) corpora lutea of both species synthesize pregnenolone, progesterone and estrogen during the entire pregnancy period, and 2) like other terrestrial carnivores in the suborder Caniformia, placentae of both species do not have the capability for synthesizing progesterone in the latter half of active pregnancy period.

3-Hydroxysteroid Dehydrogenases↗
PubMed2001

Negative correlation between plasma thyroid hormone levels and chlorinated hydrocarbon levels accumulated in seals from the coast of Hokkaido, Japan.

Chlorinated hydrocarbon (CHC) levels in the blubber of larga seals (Phoca largha) and ribbon seals (Phoca fasciata) collected from the coastal waters of Hokkaido, Japan, were determined in order to assess the hormonal effects of CHC exposure in free-ranging pinnipeds. Plasma thyroid hormone levels, including total thyroxine (T4), free thyroxine (free T4), total triiodothyronine (T3), and free triiodothyronine (free T3), were also measured. Higher concentrations of polychlorinated biphenyl congeners (PCBs), dichlorodiphenyltrichloroethane and its metabolites, and chlordane compounds were found in the range of 380 to 2,600 ng/g, 350 to 2,600 ng/g, and 120 to 760 ng/g on a wet-weight basis, respectively. Spearman rank correlation analyses showed that in larga seals, plasma total T3 and free T3 levels negatively correlated with levels of all the CHCs analyzed, although there was no such correlation between total or free T4 levels and CHC concentrations. In ribbon seals, total T3 levels significantly decreased with an increase of di-ortho PCB (PCB170 and 180) residues. These findings indicated that the plasma T3 deficiency could be associated with some CHC exposure in larga and ribbon seals and that the responses of plasma thyroid hormones may be useful biomarkers for CHC exposure in ribbon seals.

Animals↗
PubMed2000

A novel form of prostate-specific antigen transcript produced by alternative splicing.

Molecular characterization of prostate-specific antigen (PSA) has not been well elucidated, despite a great deal of clinical study. We examined the heterogeneity of PSA using reverse transcription-PCR and direct sequencing. A novel, alternatively spliced variant of the PSA transcript was found in prostate cancer (PC), as well as in benign prostatic tissue. This alternative splicing leads to the deletion of 44 amino acid residues (amino acids 45-88) from mature PSA, resulting in the loss of asparagine 45, which is a binding site for a carbohydrate chain. By these nested reverse transcription-PCR systems, this novel, alternatively spliced PSA gene was recognized in 13 of 18 (72.2%) cases with noncancerous prostate tissue, 4 of 5 (80.0%) PC cases, and 3 of 12 (25.0%) blood samples from PC patients (noncancerous prostate tissue group versus blood sample group, P = 0.011). At present, the biological significance of this alternative splicing remains to be established.

Alternative Splicing↗
PubMed1999

Detection of circulating testicular cancer cells in peripheral blood.

Patients who receive peripheral blood stem cell transplants are at risk of developing cancer recurrence due to the presence of malignant cells in the transplants. We investigated a sensitive method to detect malignant cells in the peripheral blood and peripheral blood stem cells of patients with testicular cancer using nested, reverse transcription-polymerase chain reaction (RT-PCR) to measure alpha-fetoprotein gene expression. Using this technique, a single cancer cell could be detected in 10(6) peripheral blood mononuclear cells. This is the first report of an attempt to detect circulating malignant cells in the peripheral blood of patients with testicular cancer by nested RT-PCR.

Actins↗
PubMed1999

Regulation of inner ear fluid in the rat by vasopressin.

The anti-diuretic hormone vasopressin has been shown to be important in regulating inner ear fluid. The diuretic hormone, CNP, and its receptor, ANP-B receptor, may also function in the regulation of inner ear fluid. To determine whether vasopressin directly affects the fluid level, we infused this hormone to rat and assay of V2-AVP receptor mRNA by semiquantitative RT-PCR demonstrated a significantly lower level of this transcript in vasopressin-infused animals than in saline-infused animals. The levels of CNP and ANP-B receptors mRNA, however, were the same in both groups of rats. Results suggest that high plasma levels of vasopressin may be a principal causal factor of endolymphatic hydrops in Meniere's disease, perhaps by down-regulating the number of vasopressin receptors.

Animals↗
PubMed1999

Hepatic resection for colorectal metastases: analysis of prognostic factors.

PURPOSE: Hepatic resection affords the best hope of survival for patients with colorectal carcinoma metastatic to the liver. However, recurrences are observed in about 60 percent of patients after curative hepatic resection. The purpose of this study was to examine the prognostic factors of patients undergoing curative hepatic resection for colorectal metastases. METHODS: Between April 1984 and September 1997, 168 patients underwent curative hepatic resection for colorectal metastases. The clinicopathologic factors studied for prognostic value were gender, age, primary site, nodal status of primary tumor, time of metastases, preoperative serum level of carcinoembryonic antigen, hepatic tumor size and distribution, number of metastases, type of hepatic resection, resection margin, presence of micrometastases in resected specimen and microscopic fibrous pseudocapsule between the hepatic tumor and surrounding hepatic parenchyma, nodal status of hepatoduodenal ligament, adjuvant regional chemotherapy, and perioperative transfusion. RESULTS: The overall survival was 42 percent at three years and 26 percent at five years, including a 3.5 percent 60-day surgical mortality rate. Thirty-one percent of patients had micrometastases located at a median distance of 3 mm from the metastatic tumor edge. Presence of microscopic fibrous pseudocapsule was observed in 28 percent of patients. Univariate and multivariate analyses showed that significant prognostic factors for survival were nodal status of primary tumor, number of metastases, resection margin, microscopic fibrous pseudocapsule, and adjuvant regional chemotherapy. CONCLUSIONS: We conclude that 1) hepatic resection is effective in select patients with colorectal metastases; 2) adequate resection margin and adjuvant regional chemotherapy can improve outcome; and 3) microscopic fibrous pseudocapsule may offer additional postoperative information as an independent prognostic factor.

Adult↗
PubMed1999

Expression of transitional cell-specific genes, uroplakin Ia and II, in bladder cancer: detection of circulating cancer cells in the peripheral blood of metastatic patients.

BACKGROUND: Uroplakins (UP), urothelium-specific transmembrane proteins, are present only in urothelia and may be good candidates as tumor markers specific for transitional cell carcinomas (TCC). We investigated the expression of UP-Ia and UP-II genes in the tissues and peripheral blood of patients with TCC. METHODS: We investigated UP-Ia and UP-II gene expression in tissues from 12 patients with TCC by reverse transcription-polymerase chain reaction (RT-PCR). HT1197, a TCC cell line, was used as an indicated cell line to assess a detection system for the UP-II gene-expressing cancer cells by nested RT-PCR. We also investigated UP-II gene expression in the peripheral blood of 12 other patients with TCC by nested RT-PCR. RESULTS: Prior to the investigation of UP-Ia and UP-II gene expression, a partial nucleotide sequence of human UP-II gene cDNA was determined to prepare the primers for RT-PCR. Uroplakin genes were expressed in both cancerous and non-cancerous urothelia taken from all patients examined by RT-PCR. The detection sensitivity of our assay showed that one cancer cell could be detected in 5 mL peripheral blood. UP-II gene-expression was detected in the peripheral blood from all three patients with metastatic TCC but not from the nine patients with non-metastatic TCC nor the three healthy volunteers. CONCLUSIONS: Uroplakins may be employed as tumor markers for transitional cell cancer, because they are highly conserved and well expressed, not only in non-cancerous cells but also in cancer cells. Furthermore, detection of UP-II gene expression in blood by nested RT-PCR may provide helpful information in the diagnosis and management of TCC.

Adult↗
PubMed1999

Overproduction of gamma interferon in B/Jas inbred rabbits with herpes simplex virus encephalitis.

Inbred rabbits of the B/Jas strain are highly susceptible to herpes simplex virus type-1 (HSV-1) encephalitis, developing seizures of encephalitis after intravenous injection of the KOS strain of the virus. Anti-viral interferon activity became detectable in the serum just prior to or at the onset of seizures, its level being lower in the serum than in the cerebrospinal fluid. The activity was of gamma interferon, as suggested by the acid instability and the inability of Mx protein induction. An immunohistochemical analysis of the brain tissues of encephalitic rabbits showed that MHC class I antigen was expressed on the microglia cells of inflamed lesions but not on these cells in uninflamed areas. These findings were discussed in correlation with the pathogenesis of herpetic encephalitis in the inbred rabbits.

Animals↗
PubMed1999

Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in human bladder cancer.

We investigated the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) in primary bladder cancer, its association with clinicopathologic findings, and their prognostic value. mRNA was extracted from 20 bladder cancer specimens and 6 normal bladder mucosal tissues. Relative amounts of PD-ECGF/TP mRNA were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and compared with the level of glyceraldehyde-3-phosphate dehydrogenase mRNA (used as an internal standard). PD-ECGF/TP expression was examined by immunohistochemistry in 85 patients who underwent cystectomy for bladder cancer. Serum PD-ECGF/TP levels were measured in 23 patients using a sandwich-type enzyme-linked immunosorbent assay. By RT-PCR analysis, expression of PD-ECGF/TP was found to be 7-fold higher in invasive tumors than in superficial tumors (P<0.01) and 9-fold higher than in normal bladder (P<0.01). Out of 85 transitional cell carcinoma tissue samples, 69 (81%) were evaluated as PD-ECGF/TP-positive by immunohistochemical staining. PD-ECGF/TP expression correlated significantly with tumor grade (P = 0.001), depth of invasion (P = 0.012), and lymphatic invasion (P = 0.01). No correlation was found between expression of PD-ECGF/TP and the number of tumors, tumor configuration, lymph node involvement, venous invasion, c-erbB-2 expression, or overall survival. We could not detect a significant serum level of PD-ECGF/TP in any patient. The results suggest that PD-ECGF/TP might give valuable information for bladder cancer management, though it may not be a good new tumor marker for bladder cancer.

Adult↗
PubMed1998

Expression of uroplakin Ib and uroplakin III genes in tissues and peripheral blood of patients with transitional cell carcinoma.

Uroplakins (UPs), urothelium-specific transmembrane proteins, are present only in urothelial cells. We have determined the nucleotide sequences of human UP-Ib and UP-III and synthesized specific primer pairs. The two UP genes were expressed in both cancerous and noncancerous urothelial taken from all patients examined by reverse transcription-polymerase chain reaction (RT-PCR). These genes were also detected in the peripheral blood of 3 patients with metastatic transitional cell carcinoma (TCC), but not in that from 9 patients with non-metastatic TCC or 3 healthy volunteers. The sensitivity of our assay was sufficient to detect one cancer cell in 5 ml of peripheral blood. Detection of UP gene-expression in blood by RT-PCR may provide helpful information for the diagnosis and management of TCC.

Adult↗
PubMed1997

Resistance to herpes simplex virus type 1 and its latent infection of human T cell lymphotropic virus type I-transformed T cell lines of rabbits.

Fourteen T cell lines of rabbits were infected with herpes simplex virus type 1 (HSV-1) and examined for their susceptibility to lytic infection and ability to support virus replication. T cell lines of CD4+ 8- phenotype were more vulnerable to lysis and supported higher levels of virus replication than those of other phenotypes. Cell lines of CD4+ 8+ and CD4- 8+ phenotypes continued to proliferate, while remaining productively infected, for more than a month. These latently infected cell lines could be established by treatment with anti-HSV-1 serum and complement. Viral genes were only partially expressed and the CD8 membrane antigen was down-regulated. Infected cell lines, as well as peripheral blood lymphocytes, were shown to induce meningoencephalitis when inoculated intravenously into syngeneic hosts, suggesting a possible role for infected lymphocytes in HSV-1 transport in vivo.

Animals↗
PubMed1997

In-vivo assessment of extrahepatic metabolism of paeoniflorin in rats: relevance to intestinal floral metabolism.

The extraction ratios of paeoniflorin in gut wall (EG), liver (EH) and lung (EL) were assessed by comparing AUCs after various routes of its administration to estimate the first-pass effects and the metabolism by intestinal flora. Pulmonary extraction ratio of paeniflorin was assessed by comparing AUCs calculated from venous and arterial plasma concentrations after its intravenous administration (0.5 mg kg-1). The mean pulmonary extraction ratio was estimated to be 0.06. The hepatic extraction ratio (EH was assessed by comparing AUCs after intraportal and intravenous administrations (0.5 and 5 mg kg-1). The plasma concentration profiles of paeoniflorin after intraportal administration were very close to those after intravenous administration, suggesting a negligible hepatic extraction ratio of paeoniflorin. The AUC value after intraperitoneal administration (0.5 mg kg-1) was greater than that after intraportal or intravenous administration. This finding suggests that paeoniflorin is not metabolized in the gut wall. The transference of paeoniflorin from the serosal side to the mucosal side was evaluated by the in-vitro everted sac method. The low intestinal permeability (19.4% at 60 min) was demonstrated by the comparison with phenobarbital (63.1% at 60 min). We conclude that paeoniflorin is not metabolize by gut wall, liver and lung, its poor absorption from the intestine results in extremely low bioavailability and the unabsorbed fraction of paeoniflorin is degraded by the intestinal flora.

Animals↗
PubMed1997

Streptococcal mitogenic exotoxin Z, a novel acidic superantigenic toxin produced by a T1 strain of Streptococcus pyogenes.

Streptococcus pyogenes T1 was previously found to produce an acidic mitogenic exotoxin, designated A beta, antigenically distinct from erythrogenic toxin type A (ETA) of strains T1 and NY5. Following chemical analysis and biological characterization, we have renamed this toxin streptococcal mitogenic exotoxin Z (SMEZ). Physicochemical separation of SMEZ from ETA was successfully performed on a hydrophobic chromatograph. The isoelectric point was pH 5.3, and the molecular size was estimated to be 28 kDa. These values were similar to those of ETA, but the amino acid composition and the NH2-terminal sequence of SMEZ were distinct from those of any mitogenic exotoxins hitherto described. Its mitogenic activity was found to be more potent than that of ETA in rabbit lymphocyte cultures. A specific antiserum raised against SMEZ did not cross-react with ETA, ETB, or ETC in the neutralization tests of mitogenic and erythrogenic activities. Its superantigenic nature was evident from the reverse transcriptase PCR findings of the T-cell receptor Vbeta profiles of rabbit lymphocytes stimulated in vitro. The Vbeta 8 subfamily was unique to SMEZ, while the Vbeta 2 and 6 subfamilies were found to be common among lymphocytes stimulated with ETA, ETB, ETC, or SMEZ. The results from this study provide an additional example of the diversity that exists among mitogenic or superantigenic exotoxins of streptococcal origin.

Animals↗
PubMed1996

Analysis of T cell receptor V beta expression in rabbit T lymphocytes induced to proliferate by an HTLV-I-transformed leukemogenic T cell line.

Peripheral blood lymphocytes (PBL) from rabbits of the Chbb:HM strain proliferated in coculture with an X-ray-irradiated HTLV-I-transformed leukemogenic cell line of (B/J x Chbb:HM) F1 origin, whereas PBL from rabbits of the B/J and F1 strains hardly proliferated at all in co-culture with the same cell line. A proviral HTLV-I genome was detected in high-molecular-mass DNA from these proliferating cells. An analysis of T cell receptor V beta expression revealed that these lymphocytes were of restricted V beta subfamilies, suggesting that the preferential stimulation and transformation of lymphocytes occurred in this co-culture. Staphylococcal enterotoxins similarly stimulated lymphocytes and the proliferated lymphocytes were mostly of distinct V beta subfamilies depending on stimulator enterotoxins. These results suggested that the leukemogenic cell line possesses an antigen that preferentially stimulates lymphocytes of restricted V beta subfamilies.

Animals↗
PubMed1995

Variable-region sequences for T-cell receptor-gamma and -delta chains of rabbit killer cell lines against Shope carcinoma cells.

A rabbit gamma delta killer T-cell line against Shope carcinoma cells was established from peripheral blood lymphocytes (PBL) of a human T-lymphotropic virus type I (HTLV-I)-infected rabbit bearing Shope papilloma and carcinoma. Southern hybridization analysis of this cell line with an HTLV-I probe showed that the cell line contained multiple clones of HTLV-I-transformed cells, and three sublines with different integration patterns of the HTLV-1 genome were isolated by cloning of the cell line. In all these sublines T-cell receptor (TCR)-gamma and -delta genes were rearranged and expressed. A PCR-based analysis of the expression of variable (V) genes showed that the killer cell line preferentially expressed V gamma 1.1 and V delta 1 genes, whereas V gamma 2 and V delta 1 genes were dominantly expressed in normal PBL. Analysis of the junctional sequences of TCR-gamma and -delta genes which dictate the fine specificities of epitope recognition revealed that all three sublines expressed V gamma 1.1/V delta 1 genes without the nucleotide diversity at the V-J junctions.

Amino Acid Sequence↗
PubMed1995

Genetic susceptibility to herpetic encephalitis of inbred rabbits of B/Jas strain.

Inbred rabbits of B/Jas strain were found to be highly susceptible to herpes simplex virus type 1 encephalitis, following i.v. injection of the virus, while Chbb:HM strain rabbits were not susceptible. The susceptibility trait seemed to be inherited recessively, involving multiple genes, because (B/Jas x Chbb:HM)F1 hybrids were as resistant as Chbb:HM rabbits, and because more than 90% of backcrosses of (B/Jas x Chbb:HM)F1 to B/Jas were resistant to viral inoculation. The encephalitis in B/Jas rabbits resembled human herpes simplex encephalitis, in that the temporal lobe as well as the brain stem were affected preferentially, leading to the development of various types of seizures, such as circling, loss of balance leading to a fall, and tonic and clonic convulsions. The disease could be diagnosed by magnetic resonance imaging (MRI) analysis before onset of seizures, and diseased rabbits showed a marked lymphopenia at onset of seizures.

Animals↗