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Biomedical subjects

H Wada

Publications and source records attributed to H Wada.

At least 19 recordsLinked to original sources
PubMed2003

Analysis of dystrophin mRNA from skeletal muscle but not from lymphocytes led to identification of a novel nonsense mutation in a carrier of Duchenne muscular dystrophy.

Dystrophin mRNA expressed in peripheral lymphocytes of individuals with X-linked Duchenne muscular dystrophy (DMD) has been used as a source material for mutation analysis. Here we present the first report of failure of isolation of nonsense dystrophin mRNA in lymphocytes but success in skeletal muscle in a female carrier of DMD. The mutation responsible for dystrophin-negative muscle fibers of the carrier was analysed by direct sequencing of the reverse transcription PCR product of dystrophin mRNA. In her peripheral lymphocytes, no nucleotide change was detected in the 14 kb long mRNA. Remarkably, a novel nucleotide change of C1682T in exon 12, changing glutamine codon to stop codon (Q492X) was found to be present in her skeletal muscle. This change was heterozygous. Analysis of her genomic DNA disclosed heterozygous C and T nucleotides at nt 1682, confirming the genomic origin of the nonsense mutation. Although dystrophin cDNA prepared from lymphocytes was sequenced again after subcloning, mutation-retaining clone could not be isolated. This lymphocyte-specific disappearance of nonsense mRNA strongly suggested tissue-specific skewing of X-inactivation. However, both paternal and maternal dystrophin alleles were shown to be equally expressed in lymphocytes as well as in muscle, indicating no skewing of X-inactivation in lymphocytes. We concluded that the dystrophin mRNA of the DMD carrier was destabilized in lymphocytes. Our results indicated that analysis of mRNA in lymphocytes is not enough for exact carrier diagnosis of Duchenne muscular dystrophy.

Adult↗
PubMed2003

Significance of dihydropyrimidine dehydrogenase activity in renal cell carcinoma.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme in the pathway of uracil and thymine catabolism. DPD is also the principal enzyme involved in the degradation of 5-fluorouracil (5-FU), an anticancer chemotherapeutic agent that is used clinically to treat renal cell carcinoma (RCC). Little is known about the significance of DPD activity in human cancers. We investigated the activity of DPD in 68 RCC and the relationship between DPD activity and the sensitivity to 5-FU. The levels of DPD activity in RCC and normal kidney samples were determined by the 5-FU degradation assay. The sensitivity to 5-FU was assessed by the microculture tetrazolium dye assay. The activity of DPD was approximately 2-fold higher in normal kidney compared with RCC. DPD activity in Stage I/II RCC was approximately 2-fold higher than that in Stage III/IV RCC. The levels of DPD activity in Grade 1 and Grade 2 RCC were 3 and 2-fold higher, respectively, than that in the Grade 3 cancers. There was an inverse correlation between DPD activity in RCC cells and their sensitivity to 5-FU. Furthermore, 5-chloro-2,4-dihydroxypyridine (CDHP), a potent DPD inhibitor, enhanced the sensitivity to 5-FU. The current study is the first to demonstrate that the level of DPD activity was inversel correlated with both the progression of the disease and increased grade of RCC, and that DPD activity was inversely associated with the sensitivity of RCC to 5-FU, which was enhanced by a DPD inhibitor. These results suggest that a low DPD activity may be associated with the malignant potential of RCC. In addition, it may be possible to overcome 5-FU resistance by using DPD inhibitors in the treatment protocols of 5-FU-based chemotherapy for RCC.

Adult↗
PubMed2003

Changes in gas concentrations in the Brandt endotracheal tube cuff during and after anaesthesia with nitrous oxide.

BACKGROUND AND OBJECTIVE: The mechanism underlying stable cuff pressure in the Brandt rediffusion endotracheal tube during anaesthesia with nitrous oxide is not fully understood. The present study assessed changes in gas concentrations in the cuff during and after nitrous oxide anaesthesia. METHODS: The pressure of an air-filled Brandt endotracheal tube cuff was measured; anaesthesia was maintained with nitrous oxide 67% and oxygen 33% for 6 h in the Continuous Group; oxygen was substituted for nitrous oxide after 3 h of nitrous oxide anaesthesia in the Discontinuous Group (n = 8 for each). In some other patients, the study was terminated at 90, 180, 270 and 360 min (n = 8 for each). Gas concentrations in the cuff were measured at the end of the study. RESULTS: Cuff pressures increased slightly during the first 180 min of anaesthesia (P < 0.001). Thereafter, the cuff pressure did not change significantly in the Control Group but decreased in the Discontinuous Group (P < 0.001); there was a significant difference between the two groups (P < 0.0001). Cuff pressure never exceeded 22 mmHg and there were no air leaks in either group during the 6 h anaesthesia. Nitrous oxide concentrations in the cuff were 11.3 +/- 2.6% and 2.6 +/- 0.8% in the Control Group and Discontinuous Groups, respectively; however, changes in carbon dioxide and oxygen concentrations in the cuff were within approximately 1%. CONCLUSIONS: Small changes in the nitrous oxide concentration in the cuff contribute to a stable cuff pressure in the Brandt rediffusion system, but changes in carbon dioxide or oxygen concentrations have little effect.

Adult↗
PubMed2003

Effects of sevoflurane on cerebral blood flow and cerebral metabolic rate of oxygen in human beings: a comparison with isoflurane.

BACKGROUND AND OBJECTIVE: Isoflurane is commonly used for neurosurgery but the effects of sevoflurane on human cerebral blood flow and cerebral metabolic rate of oxygen have not been fully evaluated. We therefore assessed the effects of sevoflurane and isoflurane on global cerebral blood flow and cerebral metabolic rate of oxygen in patients without noxious stimuli or neurological disorders. METHODS: General anaesthesia was induced with midazolam (0.2 mg kg(-1)) and fentanyl (5 microg kg(-1)) in 20 ASA I patients undergoing knee joint endoscopic surgery. Epidural anaesthesia was also performed to avoid noxious stimuli during surgery. Cerebral blood flow and cerebral arteriovenous oxygen content difference was measured using the Kety-Schmidt method with 15% nitrous oxide as a tracer before and after administration of either sevoflurane or isoflurane (1.5 minimum alveolar concentration, 60 min) and cerebral metabolic rate of oxygen was then calculated. RESULTS: Sevoflurane and isoflurane both increased cerebral blood flow (17%, P < 0.05; 25%, P < 0.05, respectively) and decreased cerebral metabolic rate of oxygen (26%, P < 0.01; 38%, P < 0.01, respectively). There were no significant differences in cerebral blood flow and cerebral metabolic rate of oxygen between sevoflurane and isoflurane. CONCLUSIONS: Sevoflurane and isoflurane similarly increased cerebral blood flow and decreased cerebral metabolic rate of oxygen in human beings anaesthetized with midazolam and fentanyl.

Adult↗
PubMed2002

Collapse of valence transition in Yb0.8Y0.2InCu4: pressure-induced weak ferromagnetism.

We investigated the magnetization of Yb0.8Y0.2InCu4 as a function of temperature down to 0.6 K, pressure up to 1.2 GPa, and magnetic field up to 9 T. The valence transition temperature of Yb0.8Y0.2InCu4 is lowered with applying pressure. At 0.8 GPa, collapse of the valence transition and ferromagnetic ordering occur almost simultaneously. The ferromagnetic phase at 1.2 GPa is characterized by a low Curie temperature of 1.7 K and an extremely small ordered moment of 0.05 micro(B) per Yb. Some effect of screening the ordered moment may play a key role in the ferromagnetism and the valence transition.

Journal Article↗
PubMed2002

A novel sialyl Lewis(x) analogue attenuates ischemia reperfusion injury in rabbit lung.

BACKGROUND: We investigated the effects of OJ-R9545, a novel Sialyl Lewis x analogue, on lung ischemia-reperfusion (IR) injury using an in vivo rabbit model. METHODS: The left hilum of the lung was clamped for 110 minutes; the lung was then reperfused for 90 minutes. Either OJ-R9545 (10 mg/kg) or vehicle solution was administered from 10 minutes before reperfusion to 60 minutes after reperfusion in the OJ-R (+) and OJ-R (-) group (n = 6 in each group), respectively. The sham group (n = 3) underwent an identical procedure without ischemia. RESULTS: Arterial oxygen tensions in the OJ-R (+) group were superior to those in the OJ-R (-) group from 30 to 90 minutes after reperfusion (p < 0.05 and p < 0.01). Lung wet/dry weight ratio and myeloperoxidase activity after reperfusion in the OJ-R (+) group were both significantly lower than the corresponding figures in the OJ-R (-) group (p < 0.05). The intrapulmonary leukocytes were significantly reduced in the OJ-R (+) group compared with those in the OJ-R (-) group (p < 0.01). CONCLUSIONS: OJ-R9545 attenuates lung IR injury by preventing leukocyte infiltration into the lung.

Animals↗
PubMed2002

Prognostic significance of p53 status in non-small cell lung cancer in correlation with postoperative adjuvant therapy.

BACKGROUND AND OBJECTIVE: Significant factors in the prognosis of p53 status in non-small cell lung cancer (NSCLC) remain controversial; some clinical studies have documented that p53 abnormality is a significant factor in predicting poor prognosis, and others failed. In the present study, we examined whether or not adjuvant therapy may influence the prognostic significance. METHODS: 217 patients with pathologic stage I disease were reviewed. As postoperative adjuvant therapy, UFT, an oral 5-fluorouracil derivative, was administered to 73 patients; p53 status was determined immunohistochemically. RESULTS: The 5-year survival rate for tumor with aberrant p53 expression was 66.4 %--significantly lower than that for tumor without aberrant p53 expression (79.7%, p = 0.023). The prognostic significance of p53 status was enhanced in patients who received UFT; 5-year survival rates for tumor with and without aberrant p53 expression were 68.8 and 94.7%, respectively (p = 0.002). In patients who did not receive UFT, the difference did not reach statistical significance (5-year survival rates: 65.5 and 71.5%, respectively; p = 0.267). CONCLUSIONS: This study demonstrates that postoperative survival is improved by UFT administration in patients with normal p53 function, but not in those without normal p53 function.

Antimetabolites, Antineoplastic↗
PubMed2002

Similarity between eruptions induced by sulfhydryl drugs and acute cutaneous graft-versus-host disease after bone marrow transplantation.

Cutaneous GVHD is histologically similar to eruptions induced by drugs containing a sulfhydryl group. The levels of interleukin-2 and interleukin-2 receptor were determined in a group of patients undergoing bone marrow transplantation (BMT) without graft-versus-host disease or any other complications and in a group with cutaneous graft-versus-host disease (GVHD) alone. In patients who only developed cutaneous GVHD, both interleukin-2 and inter-leukin-2 receptor levels were elevated when the disease was evident. As the elevation of these parameters became more marked, the grade of cutaneous graft versus-host disease also increased. In some patients, only one of the two parameters was elevated and the grade of graft-versus-host disease was low or no skin manifestations were seen. These findings suggest that interleukin-2 and interleukin-2 receptor act together in the development of cutaneous GVHD. This study also showed that the mechanism of cutaneous GVHD resembles that involved in the induction of eruptions by sulfhydryl-containing drugs.

Acute Disease↗
PubMed2002

Significant reduction of 125 I-meta-iodobenzylguanidine accumulation directly caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine, a toxic agent for inducing experimental Parkinson's disease.

A significant reduction of cardiac 123I-meta-iodobenzylguanidine (MIBG) accumulation has been reported in patients with idiopathic Parkinson's disease. However, it is unclear whether this reduction in cardiac sympathetic nerve is caused primarily or secondarily to the degeneration of sympathetic nerve centres which occurs in Parkinson's disease. Therefore, we examined neuronal 125I-MIBG accumulation in mice hearts of an experimental Parkinson's disease model and in sympathetic cells without any neuronal innervation. Cardiac accumulation of 125I-MIBG was determined 4h after intravenous injection of 125I-MIBG in mice pretreated with 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP), an inducer of Parkinson's disease. In an in vitro study, uptake of 125I-MIBG was determined in a cultured pheochromocytoma cell line (PC-12), which was pretreated with MPTP. MPTP reduced MIBG accumulation mainly in its neuronal component of mice hearts, suggesting that MPTP impairs cardiac sympathetic nerves to uptake MIBG. Application of MPTP also caused near-complete blockade of 125I-MIBG accumulation in PC-12 cells. In the experimental PD models, it was shown that neuronal accumulation of MIBG was impaired by the direct action of MPTP to the sympathetic cells. These findings support the idea that cardiac sympathetic nerves are primarily impaired in Parkinson's disease despite the presence or absence of systemic autonomic failure.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2001

Treatment of intestinal graft-versus-host disease using betamethasone enemas.

Intestinal graft-versus-host disease (GVHD) can readily easily induce generalized metabolic disturbance that influences morbidity and mortality after allogeneic bone marrow transplantation. Although adding a new drug or increasing the doses of immunosuppressive agents will probably be effective for controlling intestinal GVHD, the systemic side effects of such therapy cannot be ignored. In this study, we used betamethasone retention enemas as a local treatment for eight patients with refractory and/or severe intestinal GVHD. Six of the eight patients showed improvement of diarrhea and/or abdominal pain, with a reduction in the stage of GVHD. When treatment with betamethasone enemas was continued for 10 to 27 days in the 6 responding patients, no severe toxicity was observed. One patient failed to respond to treatment and another could not tolerate the enemas. Despite some uncertainty regarding the indications and duration of treatment, betamethasone enemas seem to be a potential alternative method for the management of intestinal GVHD.

Administration, Topical↗
PubMed2001

Structural characterization and chromosomal localization of the MAGE-E1 gene.

Genes of the melanoma-associated antigen (MAGE) family are characterized by the expression of tumor antigens on a malignant melanoma recognized by autologous cytolytic T lymphocytes. We have previously identified novel members of the MAGE gene family expressed in human glioma and named them MAGE-E1a-c. In the present study, we have revealed the genomic structure of MAGE-E1 by sequence analysis of a human chromosome bacterial artificial chromosome clone containing the MAGE-E1 gene. The MAGE-E1 gene is composed of 13 exons, and three of these (exon 2, exon 3 and exon 12) are alternatively spliced in each variant (E1a-c). The open reading frame encoding the MAGE-E1 peptides initiates in exon 2 and ends in exon 13. We have also demonstrated that the MAGE-E1 gene is located in Xp11 through the analysis of radiation hybrid panels. The genomic structure of MAGE-E1 is markedly similar to that of MAGE-D and its chromosomal locus is also identical to that of MAGE-D, but these features contrast with those of other MAGEs. These results suggest that MAGE-D and -E1 may be evolutionarily distant from other members of the MAGE family, and the two may be ancestral genes for the others.

Alternative Splicing↗
PubMed2001

Identification of an Arabidopsis cDNA encoding a lipoyltransferase located in plastids.

In plant cells, the pyruvate dehydrogenase (PDH) complex that requires lipoic acid as an essential coenzyme is located in plastids and mitochondria. The enzyme complex has to be lipoylated in both organelles. However, the lipoyltransferase located in plastids has not been reported. In this study, an Arabidopsis thaliana LIP2p cDNA for a lipoyltransferase located in plastids has been identified. We have shown that this cDNA encodes a lipoyltransferase by demonstrating its ability to complement an Escherichia coli mutant lacking lipoyltransferase activity, and that LIP2p is targeted into chloroplasts. These findings suggest that LIP2p is located in plastids and responsible for lipoylation of the plastidial PDH complex.

Acyltransferases↗
PubMed2001

Activity and antigen levels of thrombin-activatable fibrinolysis inhibitor in plasma of patients with disseminated intravascular coagulation.

We measured the plasma levels of thrombin-activatable fibrinolysis inhibitor (TAFI) activity and antigen in patients with disseminated intravascular coagulation (DIC) to examine the relationship between hypofibrinolysis and the pathogenesis of DIC. TAFI activity and antigen levels in the plasma were both significantly low in patients with DIC. TAFI activity in plasma was correlated with TAFI antigen, indicating that activity and antigen correspond well. The decrease of TAFI activity in DIC may be due to enhanced consumption. Since the plasma thrombin-antithrombin III complex (TAT) level was found to be elevated in DIC, increase of thrombomodulin-thrombin complex generation is suggested in this state. TAFI activity and antigen levels were negatively correlated with TAT and D-dimer, suggesting that the plasma levels of TAFI are reduced by thrombin generation. Since TAFI was not correlated with fibrinogen, plasma-alpha(2)plasmin inhibitor complex (PPIC) and tissue type plasminogen activator/plasminogen activator inhibitor-1 (tPA/PAI-1) complex, TAFI might be a secondary modulator of fibrinolysis. The TAFI activity in plasma was significantly low in patients with infection and in those with organ failure, suggesting that TAFI may play an important role in the mechanism of organ failure in DIC-associated sepsis. In brief, TAFI may play an important role in the pathogenesis of DIC and organ failure.

Antigens↗
PubMed2001

Prognostic significance of thymidylate synthase activity in bladder carcinoma.

BACKGROUND: 5-fluorouracil (5-FU) is an anticancer agent clinically used against various cancers including bladder carcinoma. 5-FU inhibits thymidylate synthase (TS) and blocks DNA synthesis. TS is the key enzyme in the catalysis of the methylation from deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate. Little is known about the significance of TS in bladder carcinoma. The authors investigated the activity of TS in 82 bladder cancers and prognostic significance of the levels of TS and/or activities of dihydropyrimidine dehydrogenase (DPD), an important enzyme in the degradation of 5-FU. METHODS: The levels of TS and DPD activities in nonfixed, fresh, frozen, bladder carcinoma and normal bladder specimens were determined biochemically by the FdUMP binding assay and the 5-FU degradation assay, respectively. RESULTS: The activity of TS was 10-fold higher in bladder carcinoma compared with normal bladder. TS activity in muscle-invasive bladder carcinoma was threefold higher than that in Ta and T1 cancer. In addition, the activity of TS in T1 bladder carcinoma was threefold higher than that in Ta cancer. The level of TS activity in Grade 3 bladder carcinoma was 4.5-fold and 3.5-fold higher than that in Grade 1 and Grade 2 cancers, respectively. Patients with Ta and T1 bladder carcinoma with low TS activity had a longer postoperative tumor-free period than those with high activity in the 2-year follow-up. Patients with Ta and T1 bladder carcinoma with high or low TS activity were divided into four subgroups: high or low DPD activity subgroups. Patients with low TS activity and high DPD activity had the longest postoperative disease-free period among the 4 subgroups during the 2-year follow-up. CONCLUSIONS: To the authors' knowledge, the current study is the first study that demonstrated that the level of TS activity correlates with both the progression of the stage and the increase of the grade of bladder carcinoma and that elevated TS activity predicts early recurrence in Ta and T1 bladder carcinoma. These results suggested that elevated TS activity might have been associated with a higher chance of progression and recurrence of bladder carcinoma in the patients who participated in this study.

Adult↗
PubMed2001

Optimal alveolar oxygen concentration for cold storage of the lung.

BACKGROUND: Ischemia of the lung is different from that of solid organs because the lung contains gas in the alveoli. However, the optimal gas composition in the alveoli during cold storage remains uncertain. We investigated the relationship between the alveolar oxygen concentration and reperfusion injury. METHODS: The lungs inflated with 0% O2, 5% O2, room air, 50% O2, or 100% O2 were reperfused after 8 hR storage at 4 degrees C and pulmonary functions were measured for 120 min using an ex vivo rat lung model. The levels of high-energy phosphate and lipid peroxidation of the lung were analyzed after a PA flush, preservation, and reperfusion. Additionally, respiration of the mitochondria in the lungs was measured after preservation. RESULTS: The pulmonary functions were significantly superior in the 5% O2 group than those in the 0% O2, 50% O2, and 100% O2 groups. Pulmonary edema developed in the 0% O2, 50% O2, and 100% O2 groups, but not in the 5% O2 group. After preservation, the energy level in the lungs decreased only in the 0% O2 group. Although lipid peroxidation of the lungs did not increase in any group after preservation, significant increases were observed in the room air, 50% O2 and 100% O2 groups after reperfusion. State 3 and 4 ratios of the mitochondrial respiration significantly decreased in the lungs of the room air, 50% O2 and 100% O2 groups. CONCLUSIONS: Although the cold-preserved lungs require oxygen, hyperoxygenation induced mitochondrial dysfunction and increased lipid peroxidation and led to deleterious lung function after reperfusion. Therefore, hypoxic conditions that can maintain the energy level of the lung during cold storage would be optimal.

Adenine Nucleotides↗
PubMed2001

ELISPOT cloning of tumor antigens recognized by cytotoxic T-lymphocytes from a cDNA expression library.

The methodology of cloning genes coding for antigens recognized by T-cells from cDNA expression libraries was improved technically by using enzyme-linked immunospot (ELISPOT) assays instead of enzyme-linked immunosorbent assays (ELISA) or bioassays to detect cytokines produced by T-cells in response to antigens. Combining large and small scale ELISPOT assays for expression cloning has the following advantages compared to conventional cDNA expression cloning: i) the number of recombinant plasmids which can be screened is greater than 10,000 per well in a 24-well plate in a large scale ELISPOT assay compared to fewer than 100 per well in a 96-well plate in an IFN-gamma ELISA or a TNF-alpha bioassay; ii) the total number of recombinant plasmids which can be screened in a routine assay is 2 x 10 (5) in only one 24-well plate in a large scale ELISPOT assay compared to 1 x 10 (5) in ten 96-well plates in an IFN-gamma ELISA or a TNF-alpha bioassay. Thus the screening efficiency of large scale ELISPOT cloning is approximately 200 times that of conventional expression cloning approaches. The efficiency of the method was confirmed by detecting the model gene RLakt from a cDNA library of a murine leukemia RL male 1.

Animals↗