Biomedical subjects

H Uemura

Publications and source records attributed to H Uemura.

At least 19 recordsLinked to original sources

PubMed2006

A key role for the subunit SUR2B in the preferential activation of vascular KATP channels by isoflurane.

BACKGROUND AND PURPOSE: It has been postulated that isoflurane, a volatile anaesthetic, produces vasodilatation through activation of ATP-sensitive K+ (KATP) channels. However, there is no direct evidence for the activation of vascular KATP channels by isoflurane. This study was conducted to examine the effect of isoflurane on vascular KATP channels and compare it with that on cardiac KATP channels. EXPERIMENTAL APPROACH: Effects of isoflurane on KATP channels were examined in aortic smooth muscle cells and cardiomyocytes of the mouse using patch clamp techniques. Effects of the anaesthetic on the KATP channels with different combinations of the inward rectifier pore subunits (Kir6.1 and Kir6.2) and sulphonylurea receptor subunits (SUR2A and SUR2B) reconstituted in a heterologous expression system were also examined. KEY RESULTS: Isoflurane increased the coronary flow in Langendorff-perfused mouse hearts in a concentration-dependent manner, which was abolished by 10 microM glibenclamide. In enzymically-dissociated aortic smooth muscle cells, isoflurane evoked a glibenclamide-sensitive current (i.e. KATP current). In isolated mouse ventricular cells, however, isoflurane failed to evoke the KATP current unless the KATP current was preactivated by the K+ channel opener pinacidil. Although isoflurane readily activated the Kir6.1/SUR2B channels (vascular type), the volatile anesthetic could not activate the Kir6.2/SUR2A channels (cardiac type) expressed in HEK293 cells. Isoflurane activated a glibenclamide-sensitive current in HEK293 cells expressing Kir6.2/SUR2B channels. CONCLUSION AND IMPLICATIONS: Isoflurane activates KATP channels in vascular smooth muscle cells and produces coronary vasodilation in mouse hearts. SUR2B may be important for the activation of vascular-type KATP channels by isoflurane.

ATP-Binding Cassette Transporters↗

PubMed2006

Association of serum undercarboxylated osteocalcin with serum estradiol in pre-, peri- and early post-menopausal women.

OBJECTIVE: We investigated changes in serum concentration of undercarboxylated osteocalcin (ucOC), which is a sensitive marker of vitamin K status, and association of ucOC concentration with estradiol concentration in pre-, peri- and early post-menopausal women. METHODS: The study population consisted of 193 pre-, peri- and post-menopausal Japanese women aged 39-66 yr. Serum ucOC concentration was measured to assess vitamin K status; serum concentrations of intact osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) were measured as bone formation markers; and urine concentration of N-telopeptide was measured as a bone resorption marker. Serum estradiol and estrone concentrations were measured by a highly sensitive radioimmunoassay. Bone mineral density (BMD) was measured at the lumbar spine. RESULTS: Serum concentration of ucOC in peri-menopausal women was significantly (p=0.0005) higher than that in pre-menopausal women, while serum OC concentration in post-menopausal women for whom 1 yr had passed since menopause was significantly (p=0.0003, p=0.024, respectively) higher than the concentrations in pre-menopausal and peri-menopausal women. Serum ucOC concentration showed a significant negative correlation with estradiol concentration (r=-0.372, p<0.0001) and a significant positive correlation with serum FSH concentration (r=0.324, p<0.0001). Serum OC concentration was positively correlated with serum FSH concentration (r=0.317, p<0.001). CONCLUSIONS: The results showed that the change in ucOC concentration during the menopausal transition is different from that in OC concentration. In addition, serum ucOC concentration is closely associated not only with FSH concentration but also estradiol concentration.

Adult↗

PubMed2006

Can monitoring of serum 8-OHdG level for 2 hours after renal transplantation predict prognosis of the graft?

8-Hydroxy-2'-deoxyguanosine (8-OHdG) is an oxidant of deoxyguanosine, a base in the construction of DNA. We examined the extent of DNA damage to the graft through oxidative stress after renal transplantation. Seven renal transplant patients were enrolled in this study. Before reperfusion of the grafts, the level of serum 8-OHdG was measured using enzyme-linked immunosorbent assay. No relationship was found between the level of serum 8-OHdG just before reperfusion and the postoperative course. In all cases, the level of serum 8-OHdG increased after reperfusion and decreased within 2 hours. In six cases, it remained almost the same as the preoperative level. A faster rate of decrease from the first peak of serum 8-OHdG was associated with a lower nadir serum creatinine and reduced occurrence of acute rejection. This study suggested that immediate calming of the oxidative stress following reperfusion may potentially have a positive influence on graft prognosis. In addition, biomarkers of oxidative stress may predict graft prognosis.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2006

Experience with laparoscopic splenectomy for ABO-incompatible living renal transplantation without plasmapheresis.

A 25-year-old male, blood type A, was admitted to our hospital for renal transplantation from his father of AB blood type. Before transplant, we performed laparoscopic splenectomy. The serum anti-B antibody titer fell from 1:8 to 1:2. Therefore, plasmapheresis was not performed. The total ischemic time was 80 minutes. Five immunosuppressive agents, including tacrolimus, mycophenolate mofetil, prednisolone, basiliximab, and deoxyspergualine, were administered in the initial period. On the 47th day, value of cytomegalovirus antibody, which was routinely measured, became positive. Hence, we administered ganciclovir, with a fall in antibody. Sixty-five days after transplant, he was discharged with a serum creatinine of 1.0 mg/dL. We concluded that it was possible to perform ABO-incompatible renal transplantation with no need for plasmapheresis or rituximab.

ABO Blood-Group System↗

PubMed2006

Creatol, an oxidative product of creatinine in kidney transplant patients, as a useful determinant of renal function: a preliminary study.

Creatol (CTL, 5-hydroxycreatinine) is a creatinine (Cr) oxidative metabolite, which was originally isolated from the urine of patients with chronic renal failure, representing a candidate for a uremic toxin. The effectiveness of CTL as an indicator of oxidative stress after kidney transplantation has not been reported. Therefore, we examined the relation between the change in oxidative stress (using CTL) in renal transplant patients and their change in renal function (using Cr). The serum Cr and serum and urine CTL were examined in five renal transplant patients. Serum CTL closely correlated with serum Cr. Serum CTL also correlated with urine CTL, but in some cases there was a time lag. Both the ratio of CTL/(Cr) and serum CTL observed in patient 2 were slow to improve after transplantation. The process through which oxidative stress was reduced was shown by the index of renal damage correlated with kidney function oxidative stress (using serum CTL) after transplantation. Our data suggested that CTL/Cr may be a good indicator of graft prognosis.

ABO Blood-Group System↗

PubMed2005

Expression of thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, and orotate phosphoribosyl transferase in prostate cancer.

The enzymes thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyl transferase (OPRT) are involved in the metabolism of the anticancer drug 5-fluorouracil. No reports have examined the expression of these enzymes in prostate cancer (CaP). A total of 25 previously untreated, hormone-sensitive CaP tissue samples and 11 benign prostatic hyperplasia (BPH) specimens were examined. Tissue of CaP and BPH tissue samples were obtained from formalin-fixed, paraffin-embedded sections by laser-captured microdissection, and then RNA was extracted. mRNA expression of TS, DPD, TP, and OPRT was analyzed by quantitative reverse transcriptase-polymerase chain reaction. TS and OPRT expression levels were significantly higher in CaP samples than in BPH. DPD expression level in poorly differentiated CaP was significantly lower than that in CaP with more favorable--well or moderately differentiated--histopathology.

Cell Differentiation↗

PubMed2005

Effect of hormone replacement therapy on the production of bone-resorbing cytokines by peripheral blood cells in postmenopausal women.

We studied the effects of hormone replacement therapy (HRT) with estrogen on postmenopausal changes in the production of bone-resorbing cytokines interleukin 1 beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha). Both cytokines were measured in the supernatants of lipopolysaccharide (LPS)-stimulated whole-blood cells from 72 untreated and 44 HRT-treated women by ELISA. The levels of IL-1beta were significantly higher in women in their 40s and 50s and in postmenopausal women than in women in their teens, 20s and 30s, while the levels of TNFalpha did not show any changes related to age. Both levels in HRT-treated women were significantly lower than those in untreated women at almost every postmenopausal stage. In a prospective study, HRT induced significant declines in both levels. These results show that estrogen decreases the accelerated production of IL-1beta and reduces the production of TNFalpha in postmenopausal women at each postmenopausal stage, even in late-postmenopausal women.

Adult↗

PubMed2005

Regulatory factors on parathyroid hormone-related peptide production by primary culture of lactating rat mammary gland.

Parathyroid hormone-related protein (PTHrP) is a major cause of humoral hypercalcemia of malignancy, but has also been widely found in fetal and adult non-neoplastic tissues. Lactating mammary gland has been shown to produce large amounts of PTHrP, and high levels of PTHrP have been measured in milk. We have examined the influences of several substances on the secretion of two different forms of PTHrP by primary cultures of mammary cells isolated from lactating rats to examine the regulatory mechanisms of PTHrP production by mammary cells. Primary cultures of mammary cells seeded at a density of 10(5) cells per 35 mm culture dish were grown on collagen gels. First, after cells were left 24 hours for attachment and incubated in 2 % FCS containing medium with for 12 hours, PTHrP (1 - 87) secretions were measured in conditioned medium with hormone supplementation for 1, 24 and 48 hours. Progesterone (10(-7) - 10(-5) mol/l) significantly suppressed PTHrP (1 - 87) secretion in a dose-dependent manner (p < 0.01), while 17beta-estradiol had no influence on PTHrP (1 - 87) secretion. Prolactin, a known stimulator of PTHrP expression in vivo, had no effect in this in vitro model. Second, PTHrP (1 - 34) secretion levels from confluent lactating mammary cells for 24 hours were evaluated. The same results were obtained in the case of PTHrP (1 - 87) secretion from non-confluent cells. Furthermore, dexamethasone (10(-6) mol/l) significantly suppressed PTHrP (1 - 34) secretion (p < 0.01). These results suggest that PTHrP production from the lactating mammary gland is suppressed by progesterone as well as dexamethasone. Progesterone dramatically falls after delivery, thus possibly accelerating PTHrP production by lactating mammary glands and resulting in considerable amounts of PTHrP secreted into the milk.

Animals↗

PubMed2003

Mutations in GCR1 affect SUC2 gene expression in Saccharomyces cerevisiae.

Transcription of SUC2, the gene that encodes the cytoplasmic and secreted forms of the enzyme invertase, is controlled by glucose repression and derepression mechanisms in Saccharomyces cerevisiae. Several regulatory factors such as the Mig1p-Tup1p-Ssn6p repressor complex and the Snf1p kinase complex have been identified previously as regulators of SUC2 expression. We show that, in addition to these factors, expression of SUC2 is affected by mutations in the gene GCR1 that encodes the glycolysis regulatory protein Gcr1p. Expression of Suc2-LacZ was not repressed by glucose in gcr1 mutant yeast cells exposed to glucose. Furthermore, secreted invertase activity was constitutively expressed under glucose-repressed and derepressed conditions in gcr1 mutants. DNA gel mobility shift assays and in-vitro DNase I protection experiments mapped a DNA binding site for Gcr1p in the transcriptional control region of the SUC2 gene, next to a previously mapped Mig1p binding site. However, the mechanism by which gcr1 mutations relieve glucose repression remains obscure.

Base Sequence↗

PubMed2003

Expression of cyclooxygenase-2 in primary superficial bladder cancer tissue may predict risk of its recurrence after complete transurethral resection.

A new modality is necessary to prevent recurrence of superficial bladder cancer after complete transurethral resection (TUR) because of the high recurrence rate even with current prophylaxis protocols. Prostaglandins (PGs) are known to be produced more in transitional cell carcinoma, and etiologically bladder cancer risk is negatively associated with the intake of non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit cyclooxygenase (COX), the rate-limiting enzyme of the PG production. We have shown the chemopreventive effect of piroxicam, an NSAID, on the N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced rat bladder cancer model. To avoid gastrointestinal side effects of regular NSAIDs, we also showed the chemopreventive effect of nimesulide, a selective inhibitor of the second isoform of COX, COX-2, which does not affect COX-l house-keeping activity in gastrointestinal mucosa on the same model. We also observed induction of COX-2 protein in the rat bladder tumor. In this study, we screened COX-2 protein expression in primary superficial bladder cancer tissues, to elucidate if COX-2 selective inhibitors can be a candidate chemopreventive agent for bladder cancer recurrence. Five and 6 samples of superficial bladder cancer cases with and without recurrence after complete TUR were examined by immunohistochemical analysis. We found more COX-2 protein positive samples in the cases with recurrence than in cases without recurrence. Even though the number of cases examined is small, this result supports our hypothesis that COX-2 contributes to superficial bladder cancer recurrence, thus, selective COX-2 inhibitors can be a candidate chemopreventive agent for the recurrence.

Adult↗

PubMed2003

Detection of circulating MN/CA9 positive renal cell carcinoma cells during operation.

Our previous study demonstrated the clear detection of MN/CA9 mRNA in peripheral blood samples from RCC patients. However, approximately 30 % of control blood samples from healthy volunteers showed MN/CA9 expression. We have developed a new primer set and optimized the PCR conditions, now resulting in a specificity of 100 %. In tissue samples, all clear cell type carcinomas but none of the spindle cell type and pleomorphic cell type tumors expressed the MN/CA9 message. Analysis of MN/CA9 messages in peripheral blood samples from RCC patients gave positive results for 0/2, 1/9, 0/4 and 4/12 of stage I, II, III and IV cases, respectively. RT-PCR analysis using preoperative renal venous blood samples resulted in clear detection of MN/CA9 positive cells in 2/4, 3/13, 2/6 and 1/1 of stage I, II, III and IV cases, respectively. Our results suggest that assessment of MN/CA9 expression by RT-PCR is a promising method for detecting cancer cells in the circulation of patients with RCC.

Adult↗

PubMed2003

[Less invasive establishment of the Fontan circulation in terms of earlier farewell to a cyanotic circulation].

To promote further improvement of surgical results in the longer terms after the Fontan procedure, we have paid attention to age at operation. Establishment of a non-cyanotic circulation at younger stage, for example around 1 year of age, could have potential advantages in postoperative cardiac performance and functional status. In order to commence the Fontan circulation safe and sound, in turn, the surgical intervention ought to be arranged in a less invasive fashion. In this respect, we introduced off-pump Fontan procedure. Since April 1996, 77 patients have undergone the off-pump Fontan procedure. Its less invasive nature was demonstrated in terms of inflammatory reaction immediately after the operation. Further devices are being sought. These include an alternative off-pump procedure even without a temporary bypass for drainage through the inferior caval vein, which has been thus far applied in 14 patients. This option proved to provide readily an excellent surgical field when an extracardiac conduit is to be anastomosed to the orifice of the inferior caval vein. Another device can be a cordial preparation of the extracardiac channel at the time of the bidirectional Glenn procedure when the staged approach is chosen.

Age Factors↗

PubMed2002

Serum osteoprotegerin/osteoclastogenesis-inhibitory factor during pregnancy and lactation and the relationship with calcium-regulating hormones and bone turnover markers.

Pregnancy and lactation induce dynamic changes in maternal bone and calcium metabolism. A novel cytokine termed osteoprotegerin (OPG)/osteoclastogenesis-inhibitory factor (OCIF) was recently isolated; this cytokine inhibits osteoclast maturation. To define the effects of pregnancy and lactation on circulating OPG/OCIF in mothers, we studied the changes in the levels of OPG/ OCIF as well as those of calcium-regulating hormones and biochemical markers of bone turnover in the maternal circulation during pregnancy (at 8-11 weeks, at 22-30 weeks, at 35-36 weeks and immediately before delivery) and lactation (at 4 days and at 1 month postpartum). Serum intact parathyroid hormone levels did not change and were almost within the normal range in this period. In contrast, serum 1,25-dihydroxyvitamin D levels increased with gestational age and were above the normal range during pregnancy. After delivery, they fell rapidly and significantly (P<0.01) to the normal range. The levels of serum bone-specific alkaline phosphatase, one of the markers of bone formation, increased with gestational age. After delivery, these levels were further increased at 1 month postpartum. The levels at 1 month postpartum were significantly higher than those at 8-11 and 22-30 weeks of pregnancy (P<0.01 and P<0.05 respectively). The levels of serum C-terminal telopeptides of type I collagen, one of the markers of bone resorption, did not change during pregnancy. After delivery, they rapidly and significantly (P<0.01) rose at 4 days postpartum, and had then fallen by 1 month postpartum. Circulating OPG/OCIF levels gradually increased with gestational age and significantly (P<0.01) increased immediately before delivery to 1.40+/-0.53 ng/ml (means+/-S.D.) compared with those in the non-pregnant, non-lactating controls (0.58+/-0.11 ng/ml). After delivery, they fell rapidly to 0.87+/-0.27 ng/ml at 4 days postpartum and had fallen further by 1 month postpartum. These results suggest that the fall in OPG/OCIF levels may be partially connected with the marked acceleration of bone resorption after delivery.

Adult↗

PubMed2001

No evidence of PEG1/MEST gene mutations in Silver-Russell syndrome patients.

Silver-Russell syndrome (SRS) is characterized by prenatal and postnatal growth retardation with morphologic anomalies. Maternal uniparental disomy 7 has been reported in some SRS patients. PEG1/MEST is an imprinted gene on chromosome 7q32 that is expressed only from the paternal allele and is a candidate gene for SRS. To clarify its biological function and role in SRS, we screened PEG1/MEST abnormalities in 15 SRS patients from various standpoints. In the lymphocytes of SRS patients, no aberrant expression patterns of two splice variants (alpha and beta) of PEG1/MEST were detected when they were compared with normal samples. Direct sequence analysis failed to detect any mutations in the PEG1/MEST alpha coding region, and there were no significant mutations in the 5'-flanking upstream region containing the predicted promoter and the highly conserved human/mouse genomic region. Differential methylation patterns of the CpG island for PEG1/MEST alpha were normally maintained and resulted in the same pattern as in the normal control, suggesting that there was no loss of imprinting. These findings suggest that PEG1/MEST can be excluded as a major determinant of SRS.

5' Flanking Region↗

PubMed2001

Hypomethylation of the MN/CA9 promoter and upregulated MN/CA9 expression in human renal cell carcinoma.

MN/CA9 is a cancer-related gene, frequently activated in human renal cell carcinomas (RCCs). To reveal the activation mechanism, we investigated the relationship between methylation status of the MN/CA9 promoter region and gene expression using 13 human RCCs, and examined the effect of in vitro CpG methylation on the MN/CA9 promoter activity using a human RCC cell line (SK-RC-44), expressing MN/CA9. MN/CA9 expression was evaluated by RT-PCR and observed in 10 of 13 RCCs (77%). A total of 9 out of 10 MN/CA9 -positive RCCs (90%) contained clear cell components. Methylation status of 6 CpGs in the MN/CA9 promoter region was decided by using the bisulfite genomic sequencing protocol. Out of 13 RCCs 9 (69%) showed partial hypomethylation of the CpG at -74 bp, while the other 4 RCCs and 3 normal kidney tissue samples showed complete methylation. Hypomethylation of the CpG at -74 bp was strongly correlated with MN/CA9 expression. Luciferase assay revealed that the MN/CA9 promoter activity was strongly suppressed by methylation of the CpG at -74 bp. These findings suggest that hypomethylation of the CpG at -74 bp in the MN/CA9 promoter region might play an important role in this gene activation of human RCC.

Carcinoma, Renal Cell↗

PubMed2001

Long and accurate PCR with a mixture of KOD DNA polymerase and its exonuclease deficient mutant enzyme.

DNA polymerase from Thermococcus kodakaraensis KOD1 (previously Pyrococcus sp. KOD1) is one of the most efficient thermostable PCR enzymes exhibiting higher accuracy and elongation velocity than any other commercially available DNA polymerase [M. Takagi et al. (1997) Appl. Environ. Microbiol. 63, 4504-4510]. However, when long distance PCR (>5 kbp) was performed with KOD DNA polymerase, amplification efficiency (product yield) becomes lower because of its strong 3'-5' exonuclease activity for proof-reading. In order to improve a target length limitation in PCR, mutant DNA polymerases with decreased 3'-5' exonuclease activity were designed by substituting amino acid residues in conserved exonuclease motifs, Exo I (Asp141-Xaa-Glu), Exo II (Asn210-Xaa-Xaa-Xaa-Phe-Asp), and Exo III (Tyr311-Xaa-Xaa-Xaa-Asp). Exonuclease activity and amplification fidelity (error rate) of the DNA polymerases were altered by mutagenesis. However, long and accurate PCR by a single-type of mutant DNA polymerase was very difficult. The wild-type DNA polymerase (WT) and its exonuclease deficient mutant (N210D) were mixed in different ratio and their characteristics in PCR were examined. When the mixed enzyme (WT and N210D) was made at the ratio of 1:40, long PCR (15 kbp) at lower mutation frequency could be efficiently achieved.

Amino Acid Sequence↗

PubMed2001

Influence of ventricular morphology on aerobic exercise capacity in patients after the Fontan operation.

OBJECTIVES: This study investigated the influences of ventricular morphology, hemodynamics and clinical findings on exercise capacity in patients after the Fontan operation. BACKGROUND: Determinants of exercise capacity after the Fontan operation remain unclear. METHODS: Peak oxygen uptake (PVo2) was determined in 105 patients by exercise test and compared to hemodynamics and clinical findings. Patients were divided into three groups based on ventricular morphology: those with a right ventricle (group RV), a biventricle (group BV) and a left ventricle (group LV). RESULTS: Ten patients with atrioventricular valve regurgitation (AVVR) or hypoxia exhibited a low PVo2. After excluding these patients, although PVo2 did not correlate with hemodynamics, except ventricular ejection fraction (p < 0.02), it correlated with age at the Fontan operation and exercise test (p < 0.002). The PVo2 was higher in group LV (63+/-9%) than in groups RV (55+/-9%) and BV (55+/-12%) (p < 0.01), while an inverse correlation between PVo2 and age at operation was demonstrated only in group RV (p < 0.05). Groups RV or BV and age at exercise test were associated with a lower PVo2, whereas group LV was an independent predictor of a higher PVo2 (p < 0.01). During 4.2 years of follow-up, a decrease in peak heart rate was related to a decrease in PVo2 (p < 0.05). The PVo2 decreased in group RV (p < 0.01). CONCLUSIONS: In addition to AVVR, hypoxia, and heart rate response, ventricular morphology is related to exercise capacity. Early Fontan operation may be beneficial in terms of exercise capacity, especially in the group RV patients.

Adolescent↗

PubMed2001

Characterization of a brain-related serine protease, neurosin (human kaillikrein 6), in human cerebrospinal fluid.

Neurosin (also known as zyme or protease M) is a trypsin-like serine protease dominantly expressed in the human brain. According to the official nomenclature, this gene is now designated as human kallikrein 6 (KLK6) and the protein is designated hK6. To investigate the metabolism of neurosin in human brain, neurosin contained in the human cerebrospinal fluid (CSF) was analyzed. Neurosin was detected in the all CSFs tested by Western blot analysis using an anti-neurosin monoclonal antibody. We purified neurosin from CSF (CSF-neurosin) using an immunoaffinity chromatography and an anion-exchange chromatography. SDS-PAGE revealed that the purified protein has a relative mol. mass (Mr) of 25,000 Da. The observed sequence of the N-terminal amino acids, Glu-Glu-Gln-Asn-Lys, of the purified CSF-neurosin was identical to the sequence of N-terminal of the pro-enzyme form, which is presumed to have no enzyme activity. CSF-neurosin neither showed any enzyme activity to Boc-Phe-Ser-Arg-4-methylcoumaryl-7-amide, which is known to be degraded by the mature neurosin, nor cleaved gelatin. To confirm that the major portion of CSF-neurosin is present in the pro-enzyme form, Western blot analysis using antibodies specific to the pro- or mature enzyme was carried out. The antibody against the mature neurosin fragment did not react with CSF-neurosin. Only the antibody against the pro-enzyme fragment detected CSF-neurosin. Thus, our results suggest that neurosin is present as an inactive pro-enzyme in the human CSF.

Amino Acid Sequence↗