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T Ota

Publications and source records attributed to T Ota.

At least 145 records · Page 8Linked to original sources
PubMed1997

G1 phase-specific suppression of the Cdk2 activity by ginsenoside Rh2 in cultured murine cells.

Ginsenoside Rh2, a plant glycoside with a dammarane skeleton resembling a steroid skeleton as an aglycone, has anticancer potentials in vitro or in vivo. To elucidate the molecular mechanisms of the effects of Rh2, we have examined the Cyclin-dependent kinase-2 (Cdk2) activity in G1 arrested B16 melanoma cells and in S phase-arrested Meth-A sarcoma cells, that have been treated with Rh2. The kinase activity was suppressed in B16 cells but not in Meth-A cells. In addition, Rh2 was found to induce G1 arrest and concomitantly suppress the Cdk2 activity in carcinogen-susceptible BALB/c 3T3 A31-1-1 and A31-1-13 cell lines. Thus, Rh2 has a G1 phase-specific suppressive effect on the Cdk2 activity, supporting further evaluation of Rh2 and its related compounds in cancer chemoprevention studies.

3T3 Cells↗
PubMed1997

Identification of strain-specific nucleotide sequences in E1 and NS4 genes of rubella virus vaccine strains in Japan.

Strain-specific nucleotide sequences of E1 and NS4 genes in five strains of a live rubella virus vaccine manufactured in Japan were identified for comparison, using 2389 nucleotides (1443 nucleotides of the E1 gene, 41 of the 3' terminal region following the E1 gene and 905 of the NS4 gene). Sequences of the E1 gene in three strains (Matsuura, TCRB19 and To-336) were identified. Takahashi and Matsuba strains shared common sequences, but were discriminated by the sequence of the NS4 gene. These five strains showed a phylogenetic relationship with the places of their isolation. In a comparative study of three strains with their unattenuated progenitors, the nucleotides in these regions were almost conserved during the attenuation process.

Base Sequence↗
PubMed1997

Influences of ultrasonic machine settings, transducer frequency and placement of region of interest on the measurement of integrated backscatter and cyclic variation.

Integrated backscatter and its cyclic variation are potentially important parameters to discriminate normal from diseased myocardium. Cyclic variation of integrated backscatter is expected to be independent of machine settings. Backscatter images of swine hearts were taken using a two-dimensional backscatter system while acoustic power was varied at different time gain control (TGC) settings. Cyclic variation was measured in vivo with various acoustic power and TGC settings using different transducer frequencies. Three different regions were analyzed. For any given TGC setting, the relationship between acoustic power and integrated backscatter in vitro was linear only over a narrow range. In vivo, cyclic variation was present at all regions studied in both long- and short-axis views. However, lower acoustic power (< 15 dB) and TGC (< 20 dB), or excessive settings of acoustic power (> 35 dB) and TGC (> 50 dB), produced minimal cyclic variation. Appropriate acoustic power (20-35 dB) and TGC (30-50 dB) produced larger and more consistent cyclic, variation at the posterior region of the left ventricle. These data indicate that each region has specific, appropriate machine settings to maximize the magnitude of cyclic variation.

Acoustics↗
PubMed1997

Inhibition of azoxymethane-initiated colon tumor by bovine lactoferrin administration in F344 rats.

The influence of bovine lactoferrin (bLF) on colon carcinogenesis was investigated in male F344 rats treated with azoxymethane (AOM). Following three weekly injections of AOM, the animals received 2 or 0.2% bLF for 36 weeks. No effects indicative of toxicity were noted, but significant reduction in both the incidence and number of adenocarcinomas of the large intestine was observed with both doses. Thus, the incidences of adenocarcinomas in the groups receiving 2% and 0.2% bLF were 15% and 25%, respectively, in contrast to the 57.5% control value (P < 0.01 and P < 0.05, respectively). The results indicate that bLF might find application for chemoprevention of colon cancer.

Adenocarcinoma↗
PubMed1997

Visualization of central stellate fibrosis in hyaline vascular type Castleman's disease.

Hyaline vascular type Castleman's disease (HVCD) is a benign cause of lymph node hypertrophy which radiologically resembles tumours such as paraganglioma and lymphoma. However, a distinguishing pathological characteristic of HVCD is the presence of central stellate fibrosis. Since conventional CT and MRI scans failed to differentiate areas of fibrosis, three-phase dynamic CT was performed on a patient who was thought to have HVCD. The images showed central fibrosis and consequently the correct pre-operative diagnosis of HVCD was made.

Adult↗
PubMed1997

Oxidative stability of liposomes prepared from soybean PC, chicken egg PC, and salmon egg PC.

The oxidative stability of phosphatidylcholines (PCs) from soybean, chicken egg, and salmon egg in liposomes was compared with that in aqueous micelles. When each PC was oxidized in aqueous micelles, salmon egg PC was the most oxidatively stable, followed by chicken egg PC and soybean PC, however, no significant difference in the oxidative stability was apparent between chicken egg PC and salmon egg PC in liposomes. The main molecular species of soybean PC was 1,2-dilinoleoyl-PC, while most of the PUFAs in chicken egg PC and salmon egg PC were not esterified at the sn-1 position but at the sn-2 position. Therefore, it is suggested that the oxidative stability of PC liposomes would be strongly influenced by the positional distribution of PUFAs in the PC molecule. Further studies on the oxidation of PC liposomes showed that chicken egg albumin and soybean protein protected PC bilayers against attack by free radicals generated in the aqueous phase.

Animals↗
PubMed1997

[The relationship between the estimated tumor growth speed and indices of bromodeoxyuridine (BrdU) incorporation and the proliferating cell nuclear antigen (PCNA) expression in superficial bladder cancer].

BACKGROUND: We previously reported that the average tumor growth speed estimated from clinical findings may be useful as a prognostic factor to determine the stage progression in superficial bladder cancer. Here, we examined the relationship between the dynamic estimation based on the average tumor growth speed and the static estimation based on the biological proliferative activity determined from bromodeoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA) indices in superficial bladder cancer. METHODS: The subjects were 11 patients with recurrent superficial bladder cancer. The tumor growth speed was calculated by dividing all tumor volume at a certain recurrence episode by the duration until the recurrence. And then, the average tumor growth speed was determined individually by calculating mean tumor growth speed for all recurrence episodes. BrdU and PCNA indices were investigated by immunohistochemical staining. RESULTS: There was a significant correlation between the average tumor growth speed and indices of PCNA and BrdU were statistically (Spearmen's rank correlation test; between the growth speed and PCNA index: p = 0.85, p < 0.01; between the average tumor growth speed and BrdU index: p = 0.71, p < 0.05; between BrdU index and PCNA index: p = 0.77, p < 0.05). The average tumor growth speed which was calculated based on clinical findings reflected the biological proliferative activities such as BrdU and PCNA indices. Furthermore, the values of all indices were higher in the invasive than in the non-invasive cases. CONCLUSIONS: These findings suggest that the average tumor growth speed as the dynamic estimation is an important prognostic factor to determine stage progression in superficial bladder cancer.

Adult↗
PubMed1997

[Chronic myelogenous leukemia expressing two bcr-abl chimeric mRNA; a case report].

Chronic myelogenous leukemia (CML) expresses two types of bcr-abl chimeric mRNA. One is b3a2 type in which bcr exon 3 binds to abl exon 2, the other is b2a2 type that bcr exon 2 binds to abl exon 2. Either bcr-abl is normally expressed, but both types of bcr-abl mRNA can be expressed at the same time in a patient. We report here a rare case of CML expressing two types of bcr-abl mRNA and discuss the possibility that this double expression would help to monitor the clinical course of CML.

Adult↗
PubMed1997

[The study for the surgical treatment on distal bile duct carcinoma].

The surgical result in 74 patients with resected distal bile duct carcinoma was reviewed to clarify the surgical strategy of distal bile duct carcinoma. The clinicopathological record was according to the General rules for surgical and pathological studies on cancer of biliary tract(the 3rd edition, edited by the Japanese society of biliary surgery). 58 patients underwent standard pancreatoduodenectomy and 16 patients had pylorus-preserving pancreatoduodenectomy. The curative resection was performed in 38 patients (51.3%). The overall 5-year survival rate (operated death included) was 35.8%. The 5-year survival rate in curative resection was 56.6%. The survival rate of patients with curative resection was significantly better than that of the patients with relative non-curative (p < 0.05) or absolute non-curative resection (p < 0.01). We concluded that the Long-term survival after surgical resection was mostly correlated with curability. To obtain curative resection, the free surgical margin of hw and ew was essential. As for free "hw", intraoperative frozen dissection was indispensable. For free "ew", the dissection of the soft tissues in retroperitoneum at the back of pancreas head was necessary. On the lymph node dissection, the lymph nodes of No 8, 12, 13, 14 should be removed.

Bile Duct Neoplasms↗
PubMed1997

Long-term survival in a case of high-risk type IgD myeloma; a possibility of effectiveness of interferon-alpha and erythropoietin.

The prognosis of patients with IgD myeloma is poorest among all types of multiple myeloma. We report a case of a patient with IgD myeloma who survived for an extraordinarily long period post-diagnosis (65 months). According to the new risk grouping of IgD myeloma (Shimamoto Y. et al., Eur. J. Haematol. 47, 262 (1991), he was classified as being in the high-risk group, with a zero percent expected 5-yr survival. Nevertheless, he survived for 65 months. We discuss the usefulness of interferon-alpha and erythropoietin for the treatment of IgD myeloma.

Antineoplastic Agents↗
PubMed1997

Water channel AQP1, 3, and 4 in the human peritoneum and peritoneal dialysate.

To clarify the mechanism of water transport driven by osmotic gradient through "ultrasmall pores" in the peritoneum, we tried to identify water channels in the peritoneum and cells in the peritoneal dialysate. Peritoneum was surgically excised from uremic patients at the insertion or removal of a catheter. Sediment was collected from 2 L of peritoneal dialysate by centrifugation at 1500 rpm. RNA was extracted and amplified by reverse transcription-polymerase chain reaction (RT-PCR). Contamination of reticulocytes was tested by the presence of ankyrin mRNA. Peritoneal tissue expressed aquaporin (AQP) 1, 3, and 4 (AQP1 > 3 > 4). Sediment of dialysate expressed mRNA of AQP1 and AQP3 (AQP1 > AQP3). The sample did not express ankyrin mRNA, indicating that the AQP1 in the sediment did not originate from reticulocytes. These data indicate that aquaporins are present in the peritoneum and might participate in water transport. Further quantitative analysis of aquaporin messages in the dialysate might clarify the pathogenesis of water removal failure.

Ankyrins↗
PubMed1997

Two optimal prefilter cutoff frequencies needed for SPECT images of myocardial perfusion in a one-day protocol.

OBJECTIVE: The purpose of this study was to determine if cutoff frequencies of two-dimensional Butterworth filters need to be changed, depending upon the amount of radiopharmaceutical administered in one-day protocols for reconstructing SPECT images of myocardial perfusion. METHODS: A scintilation camera and a phantom were used with 2.2 MBq and 10.6 MBq 99mTc. These activities corresponded to the approximate amounts used in our one-day myocardial perfusion imaging protocol. The projection data were collected in 30 positions spread over 180 degrees. Thirty- and 150-sec acquisitions per position were performed to obtain the study and the high-quality reference images. Thirteen cutoff frequencies of the filter were used to reconstruct the SPECT images. Optimal cutoff frequencies were determined by visual assessment and by calculating the normalized mean square error (n.m.s.e). These results were then compared. The same protocol was used to image three volunteers with no heart disease and the images were evaluated visually. RESULTS: In the phantom study, the optimal cutoff frequencies were 0.225 cycles/pixel for 2.2 MBq, and 0.275 cycles/pixel and 0.25 cycles/pixel for 10.6 MBq by visual inspection, and were 0.225 cycles/pixel and 0.275 cycles/pixel by calculating the n.m.s.e., respectively. In the patient study, the lower cutoff frequency of 0.20 cycles/pixel was optimal for the exercise study (low dose), while the higher cutoff frequencies of 0.275 cycles/pixel was optimal for the resting study (high dose). CONCLUSION: The optimal cutoff frequencies differed for the two activity levels. Cutoff frequencies should be changed according to the amounts of radiopharmaceuticals used for the first and the second examinations in one-day protocols.

Heart↗