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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 91 records · Page 5Linked to original sources
PubMed2001

[Study on the intensity of MMC and UFT in postoperative adjuvant chemotherapy for gastric cancer--study report of JFMTC Study No. 10].

The purpose of this study was to investigate the correlation between efficacy and dose intensity of postoperative adjuvant chemotherapy with MMC and UFT. A total of 1,410 patients from 180 institutions were allocated into a low-dose group and a high-dose group. The patients in the low-dose group received MMC at 8 mg/m2 on the day of surgery and 3 capsules of UFT (300 mg in tegafur) daily for 6 months. The patients in the high-dose group received MMC at 8 mg/m2 on the day of surgery, and in weeks 4, 10, 16, and 22 after surgery and 6 capsules of UFT (600 mg in tegafur) daily for 6 months. The patients in the high-dose group tended to exhibit higher survival rates than those in the low-dose group, although the difference was not significant. For the n(+)ps(-) patients, however, the survival rates were significantly higher in the high-dose group (p = 0.043). The recurrence-free rates showed a similar tendency. The incidence rates of adverse events were significantly higher in the high-dose group than in the low-dose group. Compliance was poorer in the high-dose group. Although the number of adverse events increases, a better prognosis can be expected with a high dose. These results confirmed a dose-dependency in adjuvant chemotherapy with MMC and UFT.

Antibiotics, Antineoplastic↗
PubMed2001

[Evaluation of cerebrovascular events in patients with rheumatoid arthritis].

OBJECTIVE: We evaluated cerebrovascular events (cerebral infarction or cerebral bleeding) in patients with rheumatoid arthritis (RA). METHODS: Prognosis and the causes of death among 1100 RA patients from 1995 to 1999, were analyzed. 34 RA patients were complicated by cerebrovascular events. About them, hemoglobin, platelet, C-reactive protein, rheumatoid factor, total cholesterol, triglyceride, duration of disease, functional class, and dose of steroids per day were measured. RESULT: Among 1100 patients with RA, 90 died at the age of 70.2. Of these patients, 24 (26.7%) died of cerebrovascular events, 19 (21.1%) of heart failure, 16 (17.8%) of infectious diseases, 10 (11.1%) of malignant tumors, and 9 (10%) of renal failure. When RA patients who died of cerebrovascular events were compared with those who died of other causes, the dose of steroid was significantly lower and the age was higher in RA patients who died of cerebrovascular events. However, there were no significant differences in total cholesterol and triglyceride levels between the two groups. Although the major cause of death in RA patients was reported to be complication by cardiovascular diseases, infectious diseases, or renal failure, the frequency of deaths was higher in elderly RA patients complicated by cerebrovascular events. When the frequency of complication by cerebrovascular events was investigated in all RA patients including those who survived, 24 died and 10 survived. The frequency of complication by cerebral infarction was higher than that of complication by cerebral bleeding in RA patients who died of cerebral events. CONCLUSION: RA patients can live longer with improvements in care and treatment, the number of elderly RA patients who may died of complication by cerebrovascular events may gradually increase.

Aged↗
PubMed2001

[Comparison of detectability of visual field abnormality by frequency doubling technology in primary open-angle glaucoma and normal-tension glaucoma].

PURPOSE: To compare the effectiveness of frequency doubling technology(FDT) in detecting abnormalities in primary open-angle glaucoma(POAG) and normal-tension glaucoma(NTG). SUBJECTS AND METHODS: Twenty-nine POAG patients (29 eyes) and 27 NTG-patients(27 eyes) were studied. All subjects underwent testing with program C-20 of FDT with appropriate corrective lenses. RESULTS: No significant differences were observed between the two groups in mean age, mean deviation(MD), and pattern standard deviation(PSD) measured by the Humphrey Field Analyzer(HFA). The correlation between MD values determined by HFA(x) and FDT(y) is represented by y = 0.60x - 2.7 (r = 0.78, p < 0.01) in the POAG group and y = 0.59x + 0.6 (r = 0.81, p < 0.001) in the NTG group. No significant difference was found in the average PSD between the two groups. In early glaucoma cases (MD > or = -5 dB by HFA), a larger proportion of cases in the POAG group than the NTG group had a lower significance level of MD determined by FDT than by HFA (p < 0.02). At many test points on the temporal periphery in FDT the mean sensitivity was lower in the POAG group than in the NTG group; whereas no significant differences among HFA test points were observed. CONCLUSIONS: FDT detected visual field abnormalities in POAG cases more sensitively than in NTG cases. This finding indicates that the pathogenesis of My-cell damage is different in POAG and NTG.

Glaucoma↗
PubMed2001

[Inhibition of HCFU absorption after resection for gastric cancer--application of hydroxyaluminium gel].

HCFU (carmofur; Mifurol) is an 5-FU analog. The maximum blood concentration of HCFU in HCFU fraction (Cmax) after gastric resection was higher than before resection. Hot sensation and pollakiuria, characteristic side effects of HCFU, are dependent on concentration of HCFU fraction in blood. Therefore, it is considered that the frequency of occurrence of side effects after gastric resection is high. For that reason, we thought that if absorption of HCFU could be reduced, fewer side effects would result. We focused on the fact that drugs which include aluminium gel may decrease absorption in combined drugs, and thought it would be possible to delay absorption in HCFU by using them. We studied the HCFU concentration in the HCFU fraction and 5-FU concentration in blood, respectively, in two cases: 1) single oral administration of HCFU 100 mg and 2) coadministration with hydroxyaluminium gel (ALG) 10 ml in the whole or partial resection of gastric cancers for 8 patients. We found that the concentration of HCFU in the HCFU fraction 2 hours after its administration decreased significantly: 3.24 +/- 1.78 (single administration), 1.37 +/- 0.91 (coadministration with ALG) (p = 0.023). HCFU concentration in the HCFU fraction seemed to decrease for coadministration with ALG in the area under the time-blood concentration curve (AUG) (p = 0.071). The 5-FU concentration did not seem to decrease in either case. From these results, the coadministration of HCFU with ALG seems to be effective for the inhibition of adverse drug reaction after the resection of gastric cancers.

Adult↗
PubMed2001

[Effect of percutaneous transvenous mitral commissurotomy for the preservation of sinus rhythm in patients with mitral stenosis].

OBJECTIVES: Atrial fibrillation is frequently associated with mitral stenosis and is considered to be an unfavorable factor for the long-term prognosis. The efficacy of percutaneous transvenous mitral commissurotomy(PTMC) was examined for the preservation of sinus rhythm in patients with mitral stenosis after PTMC. METHODS: Long-term clinical data after PTMC were obtained from 71 patients who had undergone PTMC from March 1989 to September 1999. Eighteen patients in sinus rhythm before PTMC were divided into two groups: the SR group(n = 5) who remained in sinus rhythm, and the Af group(n = 13) who showed change from sinus rhythm to persistent or paroxysmal atrial fibrillation after PTMC. RESULTS: Age, sex, mitral valve area(1.4 +/- 0.3 vs 1.2 +/- 0.3 cm2), mean mitral pressure gradient(14.3 +/- 5.5 vs 12.6 +/- 5.9 mmHg), mean left atrial pressure(15.9 +/- 7.6 vs 19.0 +/- 7.7 mmHg), left ventricular end-diastolic pressure(7.5 +/- 2.8 vs 9.3 +/- 3.9 mmHg), left ventricular end-diastolic volume index(77 +/- 13 vs 82 +/- 14 ml/m2), left ventricular ejection fraction(60 +/- 6% vs 55 +/- 4%) and cardiac output(5.1 +/- 0.4 vs 4.9 +/- 0.8 l/m2) before PTMC were not different between the two groups. Changes in mean mitral pressure gradient, mean left atrial pressure and cardiac output immediately after PTMC were not different statistically. Mitral valve area immediately after PTMC was significantly greater in the SR group compared to the Af group(2.3 +/- 0.3 vs 1.8 +/- 0.3 cm2, p < 0.05). The change in mitral valve area was also greater in the SR group(1.0 +/- 0.2 vs 0.6 +/- 0.4 cm2, p < 0.05), but there was no statistical difference in the percentage change of mitral valve area between before and immediately after PTMC(SR group 78 +/- 35% vs Af group 50 +/- 35%). End-diastolic pressure, end-diastolic volume index and ejection fraction immediately after PTMC were not statistically different. CONCLUSIONS: The final mitral valve area immediately after PTMC in the patients with mitral stenosis in sinus rhythm, but not the changes of mean mitral pressure gradient, mean left atrial pressure or cardiac output, is important for the maintenance of sinus rhythm.

Adult↗
PubMed2001

[Edge to edge repair for mitral regurgitation in a patient with chronic hemodialysis: report of a case].

In a patient with chronic hemodialysis, the high risk of calcific degeneration of biological prosthetic valve and anticoagulant related complications after valve replacement have been reported. A 71-year-old woman with hemodialysis underwent the edge to edge repair combined with ring-annuloplasty for mitral regurgitation caused by the anterior leaflet prolapse without any torn chordae. Postoperative course was uneventful. There was no significant mitral regurgitation. Double mitral orifices were confirmed by the postoperative echocardiography. A calculated functional mitral valve area was 3.06 cm2. The edge to edge repair is a simplified technique and carried out in a short time. We believe the edge to edge repair is a useful technique for anterior mitral valve prolapse in a patient with chronic hemodialysis.

Aged↗
PubMed2000

Cloning and expression of a gene encoding the flagellin of Clostridium chauvoei.

Clostridium chauvoei is a causative agent of blackleg and the major protective antigen of the organism is the flagellar protein. Using an Escherichia coli expression library of the C. chauvoei Okinawa strain, we isolated the fliC gene encoding the flagellin protein. DNA sequence analysis revealed an open reading frame of 413 amino acid residues with a calculated molecular mass of 43819Da. Comparison of the sequence with those of flagellins from other bacteria showed considerable homology in the N-terminal and C-terminal domains. The glutathione-S-transferase (GST)-flagellin fusion protein and the purified FliC protein after removing the GST part with thrombin reacted with both polyclonal antisera and the non-protective monoclonal antibody (Mab), Mo-114. However, the protective Mab, Mo-41, which may recognize its conformational epitope, failed to react with both the GST-flagellin fusion protein and the purified FliC. Furthermore, the GST-flagellin fusion protein and the purified FliC induced very little protective immunity in mice. These results suggested that a conformation-dependent epitope play an important role in the development of immunity against blackleg.

Animals↗
PubMed2000

Sterol regulatory element-binding protein-1 is regulated by glucose at the transcriptional level.

In vivo studies suggest that sterol regulatory element-binding protein (SREBP)-1 plays a key role in the up-regulation of lipogenic genes in the livers of animals that have consumed excess amounts of carbohydrates. In light of this, we sought to use an established mouse hepatocyte cell line, H2-35, to further define the mechanism by which glucose regulates nuclear SREBP-1 levels. First, we show that these cells transcribe high levels of SREBP-1c that are increased 4-fold upon differentiation from a prehepatocyte to a hepatocyte phenotype, making them an ideal cell culture model for the study of SREBP-1c induction. Second, we demonstrate that the presence of precursor and mature forms of SREBP-1 protein are positively regulated by medium glucose concentrations ranging from 5. 5 to 25 mm and are also regulated by insulin, with the amount of insulin in the fetal bovine serum being sufficient for maximal stimulation of SREBP-1 expression. Third, we show that the increase in SREBP-1 protein is due to an increase in SREBP-1 mRNA. Reporter gene analysis of the SREBP-1c promoter demonstrated a glucose-dependent induction of transcription. In contrast, expression of a fixed amount of the precursor form of SREBP-1c protein showed that glucose does not influence its cleavage. Fourth, we demonstrate that the glucose induction of SREBP could not be reproduced by fructose, xylose, or galactose nor by glucose analogs 2-deoxy glucose and 3-O-methyl glucopyranose. These data provide strong evidence for the induction of SREBP-1c mRNA by glucose leading to increased mature protein in the nucleus, thus providing a potential mechanism for the up-regulation of lipogenic genes by glucose in vivo.

Animals↗
PubMed2000

Promoter analysis of the mouse sterol regulatory element-binding protein-1c gene.

Recent data suggest that sterol regulatory-binding protein (SREBP)-1c plays a key role in the transcriptional regulation of different lipogenic genes mediating lipid synthesis as a key regulator of fuel metabolism. SREBP-1c regulates its downstream genes by changing its own mRNA level, which led us to sequence and analyze the promoter region of the mouse SREBP-1c gene. A cluster of putative binding sites of several transcription factors composed of an NF-Y site, an E-box, a sterol-regulatory element 3, and an Sp1 site were located at -90 base pairs of the SREBP-1c promoter. Luciferase reporter gene assays indicated that this SRE complex is essential to the basal promoter activity and confers responsiveness to activation by nuclear SREBPs. Deletion and mutation analyses suggest that the NF-Y site and SRE3 in the SRE complex are responsible for SREBP activation, although the other sites were also involved in the basal activity. Gel mobility shift assays demonstrate that SREBP-1 binds to the SRE3. Taken together, these findings implicate a positive loop production of SREBP-1c through the SRE complex, possibly leading to the overshoot in induction of SREBP-1c and its downstream genes seen in the livers of refed mice. Furthermore, reporter assays using larger upstream fragments indicated another region that was inducible by addition of sterols. The presence of the SRE complex and a sterol-inducible region in the same promoter suggests a novel regulatory link between cholesterol and fatty acid synthesis.

Animals↗
PubMed2000

Absence of ACAT-1 attenuates atherosclerosis but causes dry eye and cutaneous xanthomatosis in mice with congenital hyperlipidemia.

Acyl-CoA:cholesterol acyltransferase (ACAT) catalyzes esterification of cellular cholesterol. To investigate the role of ACAT-1 in atherosclerosis, we have generated ACAT-1 null (ACAT-1-/-) mice. ACAT activities were present in the liver and intestine but were completely absent in adrenal, testes, ovaries, and peritoneal macrophages in our ACAT-1-/- mice. The ACAT-1-/- mice had decreased openings of the eyes because of atrophy of the meibomian glands, a modified form of sebaceous glands normally expressing high ACAT activities. This phenotype is similar to dry eye syndrome in humans. To determine the role of ACAT-1 in atherogenesis, we crossed the ACAT-1-/- mice with mice lacking apolipoprotein (apo) E or the low density lipoprotein receptor (LDLR), hyperlipidemic models susceptible to atherosclerosis. High fat feeding resulted in extensive cutaneous xanthomatosis with loss of hair in both ACAT-1-/-:apo E-/- and ACAT-1-/-:LDLR-/- mice. Free cholesterol content was significantly increased in their skin. Aortic fatty streak lesion size as well as cholesteryl ester content were moderately reduced in both double mutant mice compared with their respective controls. These results indicate that the local inhibition of ACAT activity in tissue macrophages is protective against cholesteryl ester accumulation but causes cutaneous xanthomatosis in mice that lack apo E or LDLR.

Animals↗
PubMed2000

Mammalian cell transformation and aneuploidy induced by five bisphenols.

Bisphenol-A (BP-A), a monomer of plastics used in numerous consumer products and a xenoestrogen, induces cellular transformation and aneuploidy in Syrian hamster embryo (SHE) cells. In this study, the abilities of 4 other bisphenols to induce cellular transformation and genetic effects in SHE cells were examined and compared to BP-A. Cellular growth was inhibited by all bisphenols in a concentration-related manner. The growth inhibitory effect of the bisphenols ranked: BP-5 > BP-4 > BP-3 > BP-2 or BP-A. Morphological transformation of SHE cells was induced by BP-A, BP-3, BP-4 and BP-5, and the induced-transformation frequencies were highest with BP-4. None of the bisphenols induced gene mutations at the Na(+)/K(+) ATPase locus or the hprt locus, or chromosomal aberrations in SHE cells. By contrast, aneuploidy induction in the near-diploid range was exhibited by BP-A, BP-3, BP-4 or BP-5, corresponding to the transforming activity of each compound. The results indicate that BP-A, BP-3, BP-4 and BP-5 exhibit transforming activity in SHE cells, while BP-2 does not, and that aneuploidy induction may be a causal mechanism of the transforming activity.

Aneuploidy↗
PubMed2000

Involvement of genotoxic effects in the initiation of estrogen-induced cellular transformation: studies using Syrian hamster embryo cells treated with 17beta-estradiol and eight of its metabolites.

To examine a direct involvement of genotoxic effects of estrogens in the initiation of hormonal carcinogenesis, the abilities of 17beta-estradiol (E2) and 8 of its metabolites to induce cellular transformation and genetic effects were studied using the Syrian hamster embryo (SHE) cell model. Treatment with E2, estrone (E1), 2-hydroxyestrone (2-OHE1), 4-hydroxyestrone (4-OHE1), 2-methoxyestrone (2-MeOE1), 16alpha-hydroxyestrone (16alpha-OHE1), 2-hydroxyestradiol (2-OHE2), 4-hydroxyestradiol (4-OHE2) or estriol (E3) for I to 3 days inhibited SHE cell growth in a concentration-dependent manner. Concentration-dependent increases in the frequency of morphological transformation in SHE cells were exhibited by treatment for 48 hr with each of all estrogens examined, except for E3. The transforming activities of the estrogens, determined by the induced transformation frequencies, were ranked as follows: 4-OHE1 > 2-OHE1 > 4-OHE2 > 2-OHE2 > or = E2 or E1 > 2-MeOE1 or 16alpha-OHE1 > E3. Somatic mutations in SHE cells at the Na+/K+ATPase and /or hprt loci were induced only when the cells were treated with 4-OHE1, 2-MeOE1 or 4-OHE2 for 48 hr. Some estrogen metabolites induced chromosome aberrations in SHE cells following treatment for 24 hr. The rank order of the clastogenic activities of the estrogens that induced chromosome aberrations was 4-OHE1 > 2-OHE1 or 4-OHE2 > 2-OHE2 > E1. Significant increases in the percentage of aneuploid cells in the near diploid range were exhibited in SHE cells treated for 48 hr or 72 hr with each of the estrogens, except for 4-OHE1 and E3. Our results indicate that the transforming activities of all estrogens tested correspond to at least one of the genotoxic effects by each estrogen, i.e., chromosome aberrations, aneuploidy or gene mutations, suggesting the possible involvement of genotoxicity in the initiation of estrogen-induced carcinogenesis.

Aneuploidy↗
PubMed2000

Can insertional torque predict screw loosening and related failures? An in vivo study of pedicle screw fixation augmenting posterior lumbar interbody fusion.

STUDY DESIGN: An investigation of the relation between intraoperative insertional torque of pedicle screws, bone mineral density of the vertebra, and development of screw loosening in vivo. OBJECTIVES: To determine the usefulness of intraoperative measurement of the insertional torque of pedicle screws. SUMMARY OF BACKGROUND DATA: Some biomechanical studies have demonstrated that the insertional torque is highly correlated with bone mineral density and the stability of pedicle screws in vitro. METHODS: Pedicle screw fixation was performed with posterior lumbar interbody fusion in 62 consecutive patients. The mean age of the patients at the time of surgery was 58 years. The insertional torque of pedicle screws was measured intraoperatively in all patients. The mean follow-up period was 2.7 years. RESULTS: The mean insertional torque was 1.28 +/- 0.37 Nm in patients with screw loosening and 1.50 +/- 0. 40 Nm in patients without the problem. The mean insertional torque in patients with compression fractures in the upper vertebra adjacent to the fixed segment was 0.83 +/- 0.23 Nm. There was no significant difference between the mean insertional torque in patients with screw loosening and those without the condition. The mean insertional torque in patients without screw loosening was significantly greater than in patients with compression fractures (P < 0.01). A high correlation was found between insertional torque and bone mineral density (P < 0.01). CONCLUSIONS: Although a high correlation was found between the insertional torque of pedicle screws and bone mineral density in vivo, the insertional torque could not objectively predict screw loosening.

Bone Density↗
PubMed2000

Orphanin FQ-induced outward current in rat hippocampus.

Orphanin FQ (OFQ) is a heptadecapeptide that structurally resembles opioid peptides. It has been demonstrated that the moderate density of binding sites of OFQ were localized in the hippocampus and that the expression of OFQ receptor in the hippocampus have an important role in learning and memory. This study was designed to investigate whether activation of the OFQ receptor could induced hyperpolarization in the cultured hippocampus neurons in rats. In the current clamp mode, the application of OFQ (10(-8)-10(-5) M) hyperpolarized the membranes in cultured hippocampus neurons in a concentration-dependent manner. Moreover, in the voltage clamp mode, application of OFQ (10(-6) M) induced outward current in hippocampus CA3 pyramidal neurons. In the presence of TTX (3x10(-7) M), the average maximal amplitude of the outward current deflection induced by OFQ (10(-6) M) at -60 mV of a holding potential was 24.7+/-0.54 pA. The OFQ-induced current reversed at -99.06+/-3.80 mV (3 mM), which was quite close to the K(+) equilibrium potential as calculated by the Nernst equation (E(k)=-96.08 mV, 3 mM) for K(+) in our standard solution. This suggests that OFQ-induced current was mediated by K(+) ion. It has been demonstrated that [Phe(1)psi(CH(2)-NH)Gly(2)]Nociceptin(1-13)NH(2)) (a pseudopeptide analog of nociceptin), and nocistatin are selective antagonists of OFQ. OFQ (10(-6) M)-induced outward current was antagonized by application of [Phe(1)psi(CH(2)-NH)Gly(2)]Nociceptin(1-13)NH(2) (10(-5) M). In contrast, OFQ-induced outward current was not antagonized by application of nocistatin (10(-5) M). These results indicates that there is the physiological functioning receptor of OFQ in the hippocampus.

Animals↗
PubMed2000

Interactions between cancer and bone marrow cells induce osteoclast differentiation factor expression and osteoclast-like cell formation in vitro.

Cancer cells metastasized to bone induce osteoclastogenesis for bone destruction. Coculture of either mouse melanoma B16 or breast cancer Balb/c-MC cells with mouse bone marrow cells (BMCs) induced osteoclast-like cells, which were not observed when cancer cells were segregated from BMCs. Osteoclast differentiation factor (ODF), also known as receptor activator of NF-kappaB ligand (RANKL), is a direct mediator of many osteotropic factors. Neither BMCs, B16 nor Balb/c-MC cells alone expressed ODF mRNA. However, coculture of these cancer cells with BMCs induced ODF expression, which was prevented by indomethacin. Moreover, the coculture with cancer cells inhibited secretion of osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF), an inhibitory decoy receptor for ODF, from BMCs. Thus, enhanced osteoclastogenesis in the presence of cancer cells might be due to an increase in ODF activity. These results suggest that interactions between cancer cells and BMCs induce ODF expression and suppress OPG/OCIF level in metastatic foci resulting in pathological osteoclastogenesis for bone destruction.

Animals↗
PubMed2000

Scurvy presenting as painful gait with bruising in a young boy.

A case of scurvy occurred in an apparently well-nourished 5-year-old boy with normal growth parameters. Only after the diagnosis of scurvy was raised on clinical grounds did we discover the peculiar dietary habits that were responsible for his deficiency of ascorbic acid. His case is a reminder to the clinician that nutritionally based disease may occur in any socioeconomic setting and that nutritional screening remains an important part of every child's general health care.

Ascorbic Acid↗