Biomedical subjects

K Shibata

Publications and source records attributed to K Shibata.

At least 271 records · Page 15Linked to original sources

PubMed1996

Clinical value of CA125, CA19-9, CEA, CA72-4, and TPA in borderline ovarian tumor.

Five tumor markers were analyzed clinically in 101 patients with borderline ovarian tumors who were treated by the Tokai Ovarian Tumor Study Group, an association comprising Nagoya University and its affiliated hospital, between January 1986 and December 1994. The positive rate of CA125 was 68.2% in serous tumor and 51.9% in mucinous tumor. The positive rate of CA19-9 was 51.5% in serous tumor and 44.7% in mucinous tumor. The positive rates and mean serum levels of CA125 in serous and mucinous tumor by stage had rising tendencies with an increase in each stage. The mean serum levels of CA19-9 in serous and mucinous tumor by stage had rising tendencies with an increase in each stage. CA125 and CA19-9 were useful for screening of borderline ovarian tumors. The positive rates of CEA and TPA in mucinous tumor were 32.5 and 27.3%, respectively, although none of the patients with serous tumor were positive in CEA and TPA. The positive rates and mean serum levels of CEA in mucinous tumor by stage had rising tendencies with an increase in each stage. The positive rate of CA72-4 was significantly lower than that of CA125 (P < 0.05).

Adenocarcinoma, Mucinous↗

PubMed1996

Successful treatment of bronchial mucoepidermoid carcinoma in an 11-year-old boy by bronchoplasty: report of a case.

We report herein the rare case of an 11-year-old boy in whom mucoepidermoid carcinoma of the right upper lobe bronchus was successfully treated by bronchoplasty. The patient underwent bronchoscopy to investigate the cause of relapsing respiratory infections over the past 2 years, which revealed a tumor at the orifice of the right upper lobe bronchus. Thus, a right upper sleeve lobectomy was effectively carried out, preserving right pulmonary function. The tumor was observed to partially invade the bronchial wall, but not the lung parenchyma. Histological examination confirmed a diagnosis of mucoepidermoid carcinoma, classified as grade 2 by Conlan's classification. The patient has been well and free of recurrence for 3 years postoperatively.

Anastomosis, Surgical↗

PubMed1996

Influence of head model in biomagnetic source localization.

We evaluated the influence of the head model on biomagnetic source localization by utilizing a computer simulation. We localized the source of a magnetic field that was calculated using a realistic head model, and then evaluated the localization errors. It was seen that the sphere model adequately localized the dipole in cases near the sensor, but not in cases where the dipole was deeply situated.

Brain↗

PubMed1996

Modulation of sensitivity to mitomycin C and a dithiol analogue by tempol in non-small-cell lung cancer cell lines under hypoxia.

We examined the mechanisms involved in the bioactivation of mitomycin C (MMC) and a newly developed MMC analogue: 7-N-(2-([2-(gamma-L-glutamylamino)ethyl]dithio)ethyl)mitomycin C, KW-2149, in non-small-cell lung cancer (NSCLC) cell lines under aerobic and hypoxic conditions. To investigate these mechanisms, we used MMC-resistant non-small-cell lung cancer cell lines (PC-9/MC4) that had been established in our laboratory from the parent PC-9 cell line by continuous exposure to MMC. We previously reported that the MMC-resistant cell line (PC-9/MC4) was poor in NAD(P)H dehydrogenase (quinone) activity and approximately 6-fold more resistant than the parent cells (PC-9) to MMC on 2-h exposure under aerobic conditions. In this study, the subline PC-9/MC4 was 6.7-fold more resistant to MMC than PC-9, the parent cell line, under aerobic conditions, and 5.2-fold more resistant under hypoxic conditions after 2-h exposure to MMC. However, on co-incubation with tempol, an inhibitor of the one-electron reduction pathway, the sensitivity of PC-9/MC4 to MMC was impaired under hypoxic conditions, but the impairment was not evident under aerobic conditions. KW-2149, the newly developed MMC analogue, was cytotoxic for both PC-9/MC4 and PC-9 cells, and the sensitivity of both cell lines to KW-2149 was not changed by exposure to hypoxic conditions or by coincubation with tempol. There were no significant differences in the intracellular uptake of MMC and the activities of cytosolic detoxification enzymes between the PC-9 and PC-9/MC4 cell lines. These results support the hypothesis that the one-electron reduction pathway plays a partial role in the bioactivation of MMC, but not of KW-2149, and that KW-2149 is excellent at circumventing resistance to MMC in NSCLC.

Antineoplastic Agents↗

PubMed1996

Analysis of thrombocytopenia due to carboplatin combined with etoposide in elderly patients with lung cancer.

Thrombocytopenia induced by carboplatin combined with etoposide for elderly lung cancer patients was analyzed in relation to the predicted thrombocytopenia by the equations advocated by Egorin et al. and Taguchi et al. The thrombocytopenia actually observed was strongly correlated with and significantly more severe than that predicted if carboplatin had been administered as a single agent. The AUC (area under the curve) of carboplatin predicted by Calvert's equation significantly affected the degree of thrombocytopenia. These data suggested that dosing of carboplatin should be determined individually on the basis of renal function, as recommended earlier. The reason for the enhancement of thrombocytopenia is yet to be determined in future trials.

Aged↗

PubMed1996

Brain perfusion SPECT in neuro-Behçet's disease: discordance between Tc-99m-HMPAO and Tc-99m-ECD.

A patient with neuro-Behçet's disease was studied with both Tc-99m-HMPAO and Tc-99m-ECD brain perfusion SPECT during the same time period. In Tc-99m-HMPAO SPECT, focal high uptake was observed in the left basal ganglia where MRI depicted abnormal signal intensity. Conversely, Tc-99m-ECD SPECT did not show corresponding high uptake, but demonstrated rather low uptake in contrast to the Tc-99m-HMPAO SPECT. This case suggests that Tc-99m-HMPAO and Tc-99m-ECD may show discordant distribution in inflammatory brain disease such as neuro-Behçet's disease.

Adult↗

PubMed1996

Efficacy and safety of a percutaneous right ventricular assist system.

BACKGROUND: Mechanical right ventricular assistance is necessary in the management of profound right ventricular failure resistant to medical therapy. Conventional right ventricular assistance requires a thoracotomy. We developed a technique for assisting the failing right ventricle without thoracotomy. METHODS: We implanted the percutaneous right ventricular assist system in animals to test its feasibility and safety. A feasibility study was performed in a right ventricular failure model using 12 open chest dogs, and we examined the effects of the system hemodynamically. Next, the system was implanted into 6 goats and driven for 2 to 8 days. RESULTS: Institution of the percutaneous right ventricular assist system revealed overall hemodynamic improvement on right ventricular failure in dogs. In the goat experiment, no animal died from cannula-related complications. No damage to the intracardiac structures and no pulmonary edema were seen. Plasma free hemoglobin concentration did not exceed 10 mg/dL. CONCLUSIONS: The percutaneous right ventricular assist system is safe and effective in the management of right ventricular failure.

Animals↗

PubMed1996

The developmental increase of the AT1A, but not the AT1B, receptor mRNA level at the preoptic area in spontaneously hypertensive rats.

To determine the possible involvement of the central angiotensin system in hypertension, the angiotensin II type-1 receptor subtype mRNA levels in the preoptic area (POA) and hypothalamus were measured by means of a reverse-transcriptase/polymerase chain reaction in spontaneously hypertensive rats (SHR), and the results were then compared with the findings in age-matched normotensive Wistar-Kyoto rats (WKY). In 4-week-old (prehypertensive stage) and 7-week-old (evolving stage) SHR, the AT1A and AT1B receptor subtype mRNA levels in the POA and hypothalamus did not show any significant difference between the SHR and WKY. However, in the 16-week-old SHR (hypertensive stage), AT1A receptor subtype mRNA at POA was approximately 2-fold higher than in the WKY, while the AT1B receptor subtype mRNA showed no difference. On the other hand, neither the AT1A nor the AT1B mRNA level at the hypothalamus were different between the 16-week-old SHR and WKY. These results suggest that the AT1A mRNA level, but not the AT1B mRNA level, increases in the POA in hypertensive stage of SHR and the increase may therefore be related in some way to the state of hypertension.

Animals↗

PubMed1996

Effects of portal venous inoculation with donor splenocytes on lung allograft survival in dogs.

The effects of portal venous inoculation with donor splenocytes on lung allograft survival were evaluated in dogs. Within the dose range examined, portal venous inoculation with donor splenocytes alone did not affect the graft survival time. Although the mean graft survival time was prolonged by FK 506 treatment for 14 days, the transplanted lungs were rejected within 12 days after termination of FK 506 administration. However, when the recipients were given portal venous inoculation with donor splenocytes at the time of transplantation, the graft survival time after termination of FK 506 administration was significantly prolongated. In the recipients that received combined therapy of portal venous inoculation with donor splenocytes and FK 506 treatment, arterial oxygen tension and histologic architecture of the transplanted lungs remained within the normal range for a longer period than these measures did in control animals that received FK 506 treatment alone. Dose-response experiments revealed that 1 x 10(8) cells/recipient was most effective in causing prolonged graft survival after termination of FK 506 treatment. On the basis of these results, perioperative portal venous inoculation with donor splenocytes can enhance the immunosuppressive effect of FK 506 in the canine lung transplantation model.

Animals↗

PubMed1996

Transient upregulation of the AT2 receptor mRNA level after global ischemia in the rat brain.

The present study examined changes in angiotensin receptors (AT1 and AT2) and angiotensinogen mRNA level after global ischemia in the rat brain. The AT2 mRNA level increased by three-fold in both the cortex and hippocampus, which are known to be sensitive to ischemic injury, 3 h after ischemia. The increase thus appeared only during the early reperfusion period. In the striatum, amygdala and cerebellum, the level increased moderately 3 h and/or 24 h after ischemia; there was no change in the hypothalamus. On the other hand, the AT1A and AT1B receptor mRNA levels were not altered in the cortex or hippocampus during the early reperfusion period, even 3 h and 24 h after ischemia. There was no significant alteration in angiotensinogen mRNA level 3 h or 24 h after ischemia. These results suggest that the transient upregulation of AT2 receptor mRNA occurs in the cortex and hippocampus after injury and these changes may be in some way related to the molecular events which lead to delayed neuronal cell death.

Animals↗

PubMed1996

Spontaneous anterior interosseous nerve palsy with hourglass-like fascicular constriction within the main trunk of the median nerve.

Interfascicular neurolysis was performed in nine patients with spontaneous anterior interosseous nerve palsy. In eight of these patients, an hourglass-like constriction in the fascicles forming the anterior interosseous nerve was found within the main trunk of the median nerve at 2-7.5 cm above the medial epicondyle. The clinical signs and symptoms of these eight patients were similar to those that have been described to isolated neuritis. While the etiology remains unknown, when spontaneous anterior interosseous nerve palsy is suspected to be caused by isolated neuritis, interfascicular neurolysis should be performed to confirm the lesion and to discover whether fascicular constriction is present.

Adult↗

PubMed1996

Modulation of sensitivity to cis-diamminedichloroplatinum (II) by thromboxane A2 receptor antagonists in non-small-cell lung cancer cell lines.

We examined the effect of selective thromboxane A2 (TXA2) receptor antagonists, calcium 5(Z)-1R, 2S, 3S, 4S-7-[3-phenylsulphonylaminobicyclo [2.2.1] hept-2-yl]-5-heptonoate hydrate (S-1452) and +/- -7-(3,5,6,-trimethyl-1,4-benzoquinon-2-yl)-7-phenylhaptanoic acid (AA-2414), on sensitivity to cis-diamminedichloroplatinum (II) (CDDP) in non-small-cell lung cancer cell lines. IC50 values to CDDP using MTT assay were decreased 2.1- and 4.6-fold respectively by treatment with 250 or 500 microM S-1452, for a 2 h simultaneous drug exposure, and those of PC-9/CDDP, a CDDP-resistant cell line, were decreased 3.1- and 6.1-fold. Sensitivity to carboplatin was also enhanced by the treatment with S-1452. IC50 values to CDDP and carboplatin were decreased by treatment with AA-2414 in a dose-dependent manner. Isobologram analysis showed that the combination of CDDP with S-1452 or AA-2414 produced supra-additive or additive effects in each cell line. Neither glutathione content nor glutathione S-transferase activity was changed in either cell line by treatment with 500 microM S-1452. Accumulation of platinum into PC-9 and PC-9/CDDP was increased by the treatment in a dose-dependent manner. Na+, K+-ATPase activity of PC-9 and PC-9/CDDP was enhanced by the treatment of S-1452 in a dose-dependent manner. These data show that the TXA2 receptor antagonists may enhance the sensitivity of non-small-cell lung cancer cell lines to platinum agents. Increase in Na+, K+-ATPase activity induced by S-1452 may be the mechanism of its sensitising effect through increase in platinum accumulation.

Adenocarcinoma↗

PubMed1996

Adult T-cell leukaemia/lymphoma with multiple integrations of human T-cell lymphotropic virus type I proviral DNA: differing clinical features are linked to varied proviral integration.

Multiple integrations of human T-cell lymphotropic virus type I (HTLV-I) proviral DNA are occasionally found in tumor cells from patients with adult T-cell leukaemia/lymphoma (ATL). However, the clinical implications of multiple integrations of HTLV-I in ATL have not been well established. We studied 95 patients with ATL to elucidate the relationship between the multiple integrations of HTLV-I and the clinical characteristics. The proviral DNA of HTLV-I was examined by standard Southern blot analysis using the probe of an entire HTLV-I genome and the endonucleases with or without cleavage sites within the provirus. Multiple integrations of HTLV-I were detected in eight patients as extraordinary multiple bands; five patients showed multiple bands of the same intensity, and the remaining three showed multiple bands of differing intensities. The patients were divided into two groups based on these band patterns. One group was considered to exhibit one tumour cell clone carrying multiple copies of the provirus, whereas the other was considered to exhibit multiple tumour cell clones, each carrying one copy of the provirus. The former group of patients manifested a highly aggressive clinical course with frequent peculiar organ infiltrations, including the retina, uvea and muscle, along with the presence of large peripheral leukaemic T cells having flower-like nuclei. The latter group demonstrated an indolent clinical course with skin lesions or small leukaemic T cells having cleaved or lobulated nuclei. These findings suggest that the pattern of multiple HTLV-integrations into the tumor cell(s) has clinical implications in ATL. This may help to explain the heterogeneity of this disease.

Adult↗

PubMed1996

Dysfunction of the Orleans reeler gene arising from exon skipping due to transposition of a full-length copy of an active L1 sequence into the skipped exon.

We examined the genomic structure of the reeler gene in Orleans reeler mouse mutant. Exon skipping of the reeler gene caused a 220 bp deletion in the transcript, resulting in a frame shift of the reeler gene which disrupts the 8th EGF-like motif of the reeler product. Surprisingly, the skipped exon was inserted by the 7104 bp L1 element which carried the full-length stretch of the mouse L1 sequence, consisting of a 212 bp F-type tandem repeat, open reading frame 1 (ORF1), ORF2, the polyadenylation signal and a poly A stretch. The transposed L1 sequence was flanked by 13 bp of the target sequence at both ends. ORF1 and ORF2 of this L1 repeat element are thought to encode a component of the RNP particle and the reverse transcriptase, respectively. Orleans reeler was originally established by spontaneous mutation caused by L1 insertion, and this L1 sequence is considered to be potentially active for transposition in mouse genome.

Amino Acid Sequence↗

PubMed1996

Lidocaine attenuates the hypotensive and inflammatory responses to endotoxemia in rabbits.

OBJECTIVE: To assess the effects of lidocaine on the hemodynamic and inflammatory responses to Escherichia coli endotoxemia in rabbits. DESIGN: Prospective, randomized, controlled experimental study. SETTING: University laboratory. SUBJECTS: Twenty-seven female Japanese rabbits, anesthetized with urethane and ventilated mechanically. INTERVENTIONS: Animals were randomly assigned to one of three groups: a) endotoxemic control group (n = 9), receiving intravenous Escherichia coli endotoxin (0.5 mg/kg bolus) via the mesenteric vein; b) laparotomy control group (n = 9), treated identically to the endotoxemic control group, except for substitution of 0.9% saline for endotoxin; and c) lidocaine-treated group (n = 9), treated identically to the endotoxemic controls and additionally, intravenous lidocaine (3 mg/kg bolus, followed by infusion at 2 mg/kg/hr) was administered immediately after endotoxin MEASUREMENTS AND MAIN RESULTS: We compared hemodynamics, blood gases, and microscopic findings of lung tissue obtained at necropsy in each group. Laparotomy alone had a minimal effect on the parameters and findings. Endotoxin injection decreased mean systolic arterial pressure from 135 +/- 6 (SD) to 95 +/- 25 mm Hg (p < .05) and increased the mean base deficit from -1.2 +/- 1.8 to -14.4 +/- 4.2 mmol/L (p < .05), and caused the infiltration of neutrophils into the lungs. Lidocaine administration abolished the hypotension and attenuated the increase the base deficit to -9.5 +/- 2.1 mmol/L (p < .05) and the cellular infiltration in comparison with endotoxemic controls. CONCLUSIONS: Lidocaine attenuated the hemodynamic and inflammatory responses to endotoxemia in rabbits. Findings suggest that lidocaine administration may prevent the development of hypotension and metabolic acidosis during endotoxemia.

Acid-Base Equilibrium↗

PubMed1996

Alpha 1a-adrenoceptor polymorphism: pharmacological characterization and association with benign prostatic hypertrophy.

1. Two restriction fragment length polymorphisms of the human alpha 1a-adrenoceptor gene digested with PstI restriction enzyme exist; the nucleotide change causes the substitution of C residue for T at nucleotide 1441, thereby Arg492 to Cys492 transition, which might confer an additional putative palmitoylation site in the carboxy-terminal segment of the alpha 1a-adrenoceptor. In the present study, we compared their pharmacological properties and examined whether this alpha 1a-adrenoceptor polymorphism is associated with benign prostatic hypertrophy (BPH). 2. The frequency of alpha 1a-adrenoceptor polymorphism was not differently distributed between patients with benign prostatic hypertrophy (BPH) and normal subjects in Japan; thus, the relative frequencies of the C and T alleles were 0.90 : 0.10 in normal male subjects (n = 45) and 0.87 : 0.13 in BPH patients (n = 222), respectively. However, the frequency distribution of this polymorphism was significantly different between the Japanese and U.S. populations; thus, C and T alleles were 0.34 and 0.66 in U.S. populations. 3. Utilizing Chinese hamster ovary (CHO) cells stably expressing the two polymorphic alpha 1a-adrenoceptors (Arg492 and Cys492), we compared their binding affinity and signal transduction. Radioligand binding studies with 2-[beta-(4-hydroxy-3[125I]-iodophenyl) ethylamino-methyl]tetralone ([125I]-HEAT) showed no marked difference in the antagonist or agonist binding affinities between the two receptors. Also, both receptors were found to be coupled to the calcium signaling, and the concentration-cytosolic Ca2+ concentrations ([Ca2+]i) response relationships for noradrenaline were similar for the two polymorphic receptors. Furthermore, the receptor-mediated [Ca2+]i response was markedly desensitized after a 2 h exposure of phenylephrine (10 microM), and the extent of the desensitization was not significantly different between the two receptors. 4. In summary, the results showed that the two alpha 1a-adrenoceptors generated by genetic polymorphism have similar pharmacological characteristics, and the receptor-mediated [Ca2+]i response can be desensitized in a similar manner. The study did not provide any evidence to support the hypothesis that alpha 1a-adrenoceptor gene polymorphism is associated with BPH.

Aged↗

PubMed1996

Monoclonal antibody MAT-1 against human tyrosinase can detect melanogenic cells on formalin-fixed paraffin-embedded sections.

Immunohistochemical localization of tyrosinase was examined with a monoclonal antibody (MoAb MAT-1) against human tyrosinase on routine formalin-fixed paraffin-embedded sections of 3 normal skin specimens, 15 melanocytic tumors (6 pigmented nevi, 3 juvenile melanomas and 6 malignant melanomas) and 3 non-melanocytic tumors. In the melanotic melanomas, almost all tumor cells were clearly stained with the antibody. In the nevocytic nevi, the nevus cells in lower epidermis and upper dermis were positive for MoAb MAT-1, but negative in middle and lower dermis. All three juvenile melanomas, one amelanotic melanoma, and three non-melanocytic tumors were entirely negative for MoAb MAT-1. Thus, MoAb MAT-1 could recognize the cells with melanogenic activity on routine formalin-fixed paraffin-embedded sections. However, the staining quality was not adequate for normal epidermal melanocytes, indicating that small technical innovations in the immunostaining process such as formalin fixation after PBS washing are required. Nevertheless, MoAb MAT-1 can be expected to be very useful for identifying melanogenic cells on paraffin-embedded sections, because we have to date no other antibody available for it.

Antibodies, Monoclonal↗

PubMed1996

Detection of mouse tyrosinase with a monoclonal antibody MAT-1 against human tyrosinase.

In this study we explored the possible application of MAT-1, which has been established as a monoclonal antibody against human tyrosinase, for detection of mouse tyrosinase. The MAT-1 reacted with B16 mouse melanoma cells, but not with tyrosinase-negative NIH-3T3 mouse fibroblasts. In western blot analysis of the large granule fraction (LGF) of B16 cells, MAT-1 detected a single protein of 80 kDa, whose size was close to that of human tyrosinase detected with MAT-1 in extracts of human melanocytes. Furthermore, the 80 kDa band that was detected with MAT-1 in the LGF of B16 cells was also detected by DOPA reaction. In order to confirm that the protein detected with MAT-1 is tyrosinase, a transient expression assay was carried out. When mouse tyrosinase or mouse tyrosinase-related protein-1, which shares high homology with human tyrosinase, was transiently expressed in tyrosinase-negative K1735 mouse melanoma cells by cDNA transfection, MAT-1 reacted only with the cells expressing mouse tyrosinase. These results indicate that MAT-1 specifically reacts with mouse tyrosinase.

Animals↗