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Koichi Suzuki

Publications and source records attributed to Koichi Suzuki.

At least 73 records · Page 4Linked to original sources
PubMed2004

Analysis of two types of novel alleles in the DXS10011 locus.

A population study of the short tandem repeat locus DXS10011 was carried out in a sample of 104 unrelated Japanese individuals (56 males, 48 females). Thirty-six different alleles were distinguished. The power of discrimination was 0.933 (male) and 0.997 (female). Sequence analysis of alleles was examined for 34 samples. The sequence structures of the alleles were classified into three types: A, B and C. Type A had a regular repeat structure of the repeat region: (GAAA)(n). Types A and B differed in the base sequence of the repeat region. As an A (adenine) insertion in 5' upstream of (GAAA)(n) repeat unit was type C, this type was differentiated from type A.

Chromosomes, Human, X↗
PubMed2004

Fatality due to acute fluoride poisoning in the workplace.

We report a case of a 65-year-old worker who suffered a third-degree skin burn to 5% of his total body surface area as a result of being splashed in the face with hydrofluoric acid (HF). He died shortly thereafter without having received adequate first aid. His serum fluoride concentration was markedly increased at 6.38 mg/dl with hypocalcemia and hyperkalemia. We concluded that he died of HF poisoning. In this case he might have managed to avoid death if he had not been working alone and if he had received adequate first aid on the scene as soon as possible. We re-emphasize the need for the immediate initiation of first aid on the scene and the distribution of information on the risks of HF to workers.

Accidents, Occupational↗
PubMed2004

The modulatory effect of pyrethroids on acetylcholine release in the hippocampus of freely moving rats.

The peripheral effects of pyrethroids on Na(+) channels are well known but the effects on CNS neurotransmission are less known. In the present study, type I and II pyrethroids were found to affect the release of acetylcholine (ACh) from hippocampus in freely moving rats as measured by in vivo microdialysis. The basal release of ACh from the hippocampus of untreated rats was 6.6 pmol/10 microl/10 min. Allethrin had an interesting dual effect on ACh release, increasing ACh efflux (to about 300% of baseline) at the lower dose of 20 mg/kg i.p. with a peak time of 60 min and decreasing the efflux (to about 40% of baseline) at the higher dose of 60 mg/kg i.p. up to 3 h after administration. Cyhalothrin 20 and 60 mg/kg i.p. inhibited the release (to about 30% of baseline) dose-dependently, with a peak time of 50-60 min after administration. Deltamethrin 20 mg/kg i.p. increased the efflux (to about 250% of baseline) with a peak time of 30 min after administration and 60 mg/kg i.p. increased the efflux (to about 450% of baseline) and remained at a steady level during the rest of the 3 h experiment. Control vehicle injections had no effect on the efflux of ACh in any of the experiments. This is the first report, using in vivo microdialysis, that pyrethroids modulate the ACh release in the hippocampus of rat brain.

Acetylcholine↗
PubMed2004

Signal transduction pathways mediated by the interaction of CpG DNA with Toll-like receptor 9.

Synthetic oligodeoxynucleotides (ODN) expressing non-methylated "CpG motifs" patterned after those present in bacterial DNA have characteristic immunomodulatory effects. CpG DNA is recognized as a pathogen-associated molecular pattern, and triggers a rapid innate immune response. CpG ODN are being harnessed for a variety of therapeutic uses, including as immune adjuvants, for cancer therapy, as anti-allergens, and as immunoprotective agents. The signal transduction pathway mediated by the engagement of CpG DNA with Toll-like receptor 9 (TLR9) is shared with other members of the TLR family. Recent studies demonstrate that formation and maturation of CpG DNA-containing endosomes are regulated by phosphatidylinositol 3 kinases and the Ras-associated GTP-binding protein, Rab5, which are essential for the initiation of TLR9-mediated signaling.

Animals↗
PubMed2004

Combined therapy of enalapril and losartan attenuates histologic progression in immunoglobulin A nephropathy.

BACKGROUND: It has been reported that combined therapy of angiotensin converting enzyme inhibitor and angiotensin receptor blocker significantly decreases proteinuria in immunoglobulin A (IgA) nephropathy. However, histologic alterations following the therapy have not been reported. METHODS: A total of nine Japanese children with severe proteinuric IgA nephropathy who received a prompt immunosuppressive therapy were enrolled the study, four of whom received a combined therapy of angiotensin converting enzyme inhibitor, enalapril and angiotensin receptor blocker, losartan (Group A), while the remaining five did not (Group B). All underwent renal biopsy before and approximately 12 months after the first renal biopsy. RESULTS: At presentation, urine protein excretion and the histologic indices of mean activity index, mean chronicity index and tubulointerstitial scores did not show a statistical difference between the two groups: Group A (2.6 +/- 0.6 g/day; mean activity index, 5.0 +/- 1.0; mean chronicity index, 5.0 +/- 1.0; tubulointerstitial scores, 4.3 +/- 1.0) and Group B (2.2 +/- 0.6 g/day; mean activity index, 4.8 +/- 0.8; mean chronicity index, 4.8 +/- 1.3; tubulointerstitial scores, 3.6 +/- 0.5, respectively). All had normal blood pressure and renal function. Urine protein excretion and the activity index decreased at the second renal biopsy, while the chronicity index and the tubulointerstitial scores slightly increased or remained unchanged. In comparison with Group B, a significant suppression in increasing the chronicity index and the tubulointerstitial scores obtained at the second renal biopsy were observed in Group A [Group A: 4.3 +/- 1.2 and 3.0 +/- 0.0, respectively, vs Group B: 6.0 +/- 0.7 and 4.4 +/- 0.9, respectively (P < 0.05)]. One patient in Group B developed chronic renal insufficiency thereafter. CONCLUSIONS: Although only a small number of patients were examined, these clinical findings suggest that a combined therapy of enalapril and losartan may attenuate histologic progression in at least a proportion of patients with severe proteinuric IgA nephropathy.

Adolescent↗
PubMed2004

Microgravity experiments on boiling and applications: research activity of advanced high heat flux cooling technology for electronic devices in Japan.

Research and development on advanced high heat flux cooling technology for electronic devices has been carried out as the Project of Fundamental Technology Development for Energy Conservation, promoted by the New Energy and Industrial Technology Development Organization of Japan (NEDO). Based on the microgravity experiments on boiling heat transfer, the following useful results have obtained for the cooling of electronic devices. In subcooled flow boiling in a small channel, heat flux increases considerably more than the ordinary critical heat flux with microbubble emission in transition boiling, and dry out of the heating surface is disturbed. Successful enhancement of heat transfer is achieved by a capillary effect from grooved surface dual subchannels on the liquid supply. The critical heat flux increases 30-40 percent more than for ordinary subchannels. A self-wetting mechanism has been proposed, following investigation of bubble behavior in pool boiling of binary mixtures under microgravity. Ideas and a new concept have been proposed for the design of future cooling system in power electronics.

Cold Temperature↗
PubMed2004

A study of subcooled pool boiling of water: contact area of boiling bubbles with a heating surface during a heating process.

The contact area of bubbles with a transparent heating surface was optically measured during subcooled pool boiling of water on the ground. In the experiments, boiling bubbles were attached to the heating surface with a bubble holder and nearly reproduced the bubble behavior observed in low gravity. DC power was applied to the ITO heater and increased until the heater surface burned out. In quick heating, that is about 20 second until burnout and equal to the heating time during the low gravity period, the contact area was smaller than that for long time heating at the same heat flux. The experimental results suggest the reason why the critical heat flux in pool boiling is higher than the widely accepted predictions in microgravity. In a drop shaft experiment with constant heating, the contact area increased dramatically at the start of microgravity and became constant. Boiling bubbles coalesced and remained just over the heating surface.

Earth, Planet↗
PubMed2004

Assessment of coronary artery calcification in hemodialysis patients using multi-detector spiral CT scan.

Cardiovascular disease in association with coronary artery calcification (CAC) is the leading cause of death in patients with end-stage renal disease (ESRD). The evaluation of CAC has been performed by electron beam CT scan. The purpose of the present study was to assess CAC using multi-detector spiral CT (MDCT) and to evaluate contributors to CAC in these patients. Fifty-three patients on chronic hemodialysis participated in this study. Their mean age was 61.0+/-9.6 years, and the mean duration of dialysis therapy was 6.7+/-5.4 years. We used an automatic device to measure arterial pulse wave velocity (PWV) as an index of arterial wall stiffness. The aortic calcification index (ACI) was quantified morphometrically by CT scan. The CAC score correlated positively with ACI score (r =0.863, p <0.0001). Linear regression analysis indicated that the CAC scores correlated positively with age (r =0.406, p =0.0023), C-reactive protein (r =0.38, p =0.0047) and PWV (r =0.303, p =0.0271). Stepwise regression analysis indicated that ACI (beta-coefficient=0.862, p <0.0001) and arterial PWV (beta-coefficient=0.303, p <0.0001) were independently associated with CAC score. The mean CAC score of patients with cardiac events (2,568.5+/-2,575.1 mm3) was significantly higher than that (258.0+/-409.2 mm3) of patients without cardiac events. In conclusion, our results showed clearly that assessment of CAC score using MDCT may be predictive for detecting the presence of coronary artery disease. CAC is indirectly associated with increased arterial stiffness and the extent of aortic calcification in hemodialysis patients. We did not find a significant correlation between CAC score and parameters of mineral metabolism, including serum levels of calcium, phosphorus and parathyroid hormone. A longitudinal prospective study is required to assess the predictive value of this technique in determining cardiac events in large numbers of hemodialysis patients.

Aged↗
PubMed2004

Incidence of bladder cancer discovered by urethrocystoscopy at prostate biopsy: extraordinary high incidence of tiny bladder cancer in elderly males.

In order to clarify the incidence of bladder cancer with and without prostate cancer, we investigated bladder cancer discovered incidentally by urethrocystoscopy at prostate biopsy. Between April 1997 and December 2003, 498 patients who were suspected prostate cancer were performed prostate biopsy and urethrocystoscopy simultaneously. We investigate possible invasion of prostate cancer into the urethra or bladder mucosa as well as bladder cancer, including other benign lesions of the bladder by urethrocystoscopy. Prostate cancer was confirmed in 175 (35.1%) of the 498 patients histologically, and bladder cancer was discovered incidentally in 12 patients (2.4 %). The incidence of bladder cancer in patients with prostate cancer of 2.3% (4/175) was not significantly different from that in patients without prostate cancer, which was 2.5% (8/323). Superficial and those with a size less than 1 cm were noted in 11 patients (92%) and 10 patients (83%) respectively. High incidence rate of bladder cancer with prostate cancer was reported previously, however, there was no study to compare the incidence rate of bladder cancer between cases with and without prostate cancer. The present study suggests that asymptomatic tiny bladder cancer may be present at an unexpectedly high incidence rate in elderly males.

Adult↗
PubMed2004

Structure, activation, and biology of calpain.

Variation in the calpain 10 gene has recently been shown to be associated with type 2 diabetes by positional cloning. Since then, studies on calpain 10 have been started in correlation with diabetes and insulin-mediated signaling. In this review, the activation mechanism of calpain by calcium ions, which is essential to understand its physiological functions, is discussed on the basis of recent X-ray structural analyses. Further, special features of the structure of calpain 10 that differ from those of typical micro - or m-calpain used in most studies are summarized together with discussion of the physiological function of calpain with respect to type 2 diabetes.

Calcium↗
PubMed2004

[Sling removal after the Vesica sling and tension-free vaginal tape (TVT) procedures].

PURPOSE: We describe our experience of sling removal performed after either the Vesica sling procedure (due to vaginal erosion or at the time of reoperation for recurrent stress incontinence) or the tension-free vaginal tape (TVT) procedure (due to persistent urinary retention). MATERIALS AND METHODS: From May 1997 to December 2002, we performed 19 Vesica sling procedures and 66 TVT procedures for the treatment of urodynamic stress incontinence. In the former procedures, four patients (21%) developed vaginal erosion and underwent total or partial removal of sling material (Hemashield made from bovine-collagen-injected woven polyester). In another three patients, stress incontinence recurred 2-4 years after the Vesica sling procedure, and they underwent total sling removal and the TVT procedure. Before using the urethral pull-down process (UPDP) in TVT procedures, 2 out of 23 patients (8.7%) developed persistent urinary retention and underwent either sling release alone or partial sling removal concomitant with a second TVT procedure. After the introduction of the UPDP, no patient developed urinary retention. RESULTS: Three patients in whom total sling removal was performed due to vaginal erosion after a Vesica sling procedure developed recurrent stress incontinence. One patient who underwent partial sling removal remained continent, but vaginal erosion recurred 2 years later. Patients who had total sling removal and TVT procedures due to recurrent stress incontinence after Vesica sling procedure became continent with an uneventful postoperative course. One patient who underwent transvaginal release of TVT tape (polypropylene mesh) due to urinary retention after the TVT procedure developed recurrent stress incontinence, and the other who underwent partial removal of TVT tape and a second TVT procedure had resolution of urinary retention without recurrence of stress incontinence. CONCLUSION: Prompt and total sling removal should be recommended for vaginal erosion after the Vesica sling procedure. In patients with urinary retention after the TVT procedure, partial removal of TVT tape and a second TVT procedure using the UPDP to prevent overtightness may be a preferable choice to attain both continence and resolution of urinary retention.

Adult↗
PubMed2004

[Two cases of ammonium acid urate urinary stones related to anorexia nervosa and laxative abuse].

We report two cases of urolithiasis related to anorexia nervosa and laxative abuse. Case 1: A 21-year-old woman was referred to our hospital because of left flank pain. A left ureteral stone, 10 x 6 mm in size, was successfully fragmented by extracorporeal shock-wave lithotripsy (ESWL), but she experienced repetitive formation of bilateral urinary stones and double J stent encrustation which required 13 sessions of ESWL, one session of transurethral ureterolithotripsy and one session of cystolithotripsy over a period of 5 years. All stones were comprised of pure ammonium acid urate. It was later revealed that she was diagnosed with anorexia nervosa at 15 years old and had suffered from laxative abuse (bisacodyl, 300-500 mg/day) ever since. Case 2: A 18-year-old woman was referred to our hospital because of left lower abdominal pain. A left renal stone, 15 x 10 mm in size, was successfully fragmented by ESWL, but she had double J stent encrustation which was managed by cystolithotripsy. All stones were comprised of pure ammonium acid urate. She was later diagnosed with anorexia nervosa and it turned out that she had suffered from an eating disorder and laxative abuse (bisacodyl, 200 mg/day) since the age of 15 years. Both patients had marked decrease in urine volume, hyponatremia and hypokalemia. Anorexia nervosa and laxative abuse should be suspected whenever a woman has an ammonium acid urate stone in sterile urine because the treatment of these disorders is crucial to the prevention of repetitive formation of urinary stones.

Adolescent↗
PubMed2004

Effects of cyclic intermittent etidronate therapy on coronary artery calcification in patients receiving long-term hemodialysis.

BACKGROUND: Coronary artery calcification (CAC) is thought to be associated with greater cardiovascular mortality in patients with end-stage renal disease than in nonuremic persons. The purpose of the present study is to assess the effects of etidronate, a synthetic analogue of pyrophosphate, on progression of CAC score. METHODS: The extent of CAC was evaluated by using multidetector spiral computed tomography. Repeated CAC score estimation was possible in 35 patients (29 men, 6 women). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Serum osteoprotegerin (OPG) was measured by using enzyme-linked immunoassay. Serum etidronate was measured by means of the gas spectrometry technique using deuterium-labeled etidronate as internal standard. RESULTS: Mean patient age was 63.2 +/- 8.2 (SD) years, and mean duration of dialysis therapy was 7.4 +/- 5.5 years. CAC score was estimated 3 times in each patient. After the second CAC score estimation, 35 patients were administered etidronate, 200 mg/d, for 14 days. This cycle was repeated 3 times every 90 days. CAC progression was significantly less pronounced during treatment with etidronate compared with the period before treatment was initiated. The median annualized absolute increase in calcified volume was 195.0 mm3 without treatment compared with -490.0 mm3 during treatment ( P < 0.01). Patients were divided into 2 groups based on changes in CAC score during etidronate treatment. Responders (n = 26) were patients whose CAC score decreased during therapy, and nonresponders (n = 9) were patients whose CAC score increased, even after etidronate therapy. Serum C-reactive protein values (0.18 +/- 0.13 mg/dL) in the responder group were greater than those (0.14 +/- 0.08 mg/dL) in the nonresponder group ( P = 0.013). Serum OPG levels decreased significantly during etidronate therapy (256.8 +/- 93.8 versus 245.0 +/- 83.0 pg/mL; P = 0.0161). Etidronate was well tolerated during the study. BMD values during etidronate therapy were not significantly changed from 0.941 +/- 0.125 to 0.968 +/- 0.246 g/cm2. CONCLUSION: Results of the present study suggest that the extent of CAC may be suppressed by etidronate in association with a reduction in chronic inflammatory responses. They also suggest that a decrease in serum OPG concentrations by means of etidronate may be associated with changes in vascular calcification in dialysis patients.

Aged↗
PubMed2003

Newly identified exons encoding novel variants of p94/calpain 3 are expressed ubiquitously and overlap the alpha-glucosidase C gene.

There are two classes of an intracellular 'modulator protease', calpain: ubiquitous and tissue-specific. p94/calpain 3 is an example of the latter, predominantly expressed in muscle. A defect in the p94 gene causes muscular dystrophy. Here we report that human and mouse p94 genes have a possible novel alternative promoter expressing p94 variants in all tissues examined including human lens epithelial cells. The possible promoter region and the following novel exons overlap the 3' region of the neutral alpha-glucosidase C gene. Unlike p94, the novel p94 variants expressed in COS7 cells do not undergo rapid autolysis, suggesting basic functions different from p94.

Amino Acid Sequence↗
PubMed2003

Repeat renal biopsy in children with severe idiopathic tubulointerstitial nephritis.

Idiopathic (primary) tubulointerstitial nephritis (TIN) of childhood is relatively rare. Four children, two with concomitant uveitis, aged 8-14 years, with idiopathic TIN who underwent repeat renal biopsy were retrospectively evaluated. At presentation, all had a significant elevation of the urinary beta(2)-microglobulin/creatinine ratio (beta2MG ratio), ranging from 10100 to 44550, with increased histological indices of tubulointerstitial scores (TI scores) in excess of 6 points. Three of the children received prednisolone (PSL) therapy following diagnosis, while the remaining child received the therapy 30 months after the first renal biopsy. In the children that received prompt PSL therapy, a rapid decrease in urinary beta2MG ratio was observed and the TI scores obtained at a mean interval of 16 months after the first biopsy decreased to less than 5, while preserving renal function. In the remaining child that received delayed PSL therapy, persistent elevations of urinary beta2MG ratio and TI scores were observed. He subsequently progressed to chronic renal insufficiency. These clinical findings suggest that persistent elevations of urinary beta2MG ratio and TI scores are indicators of progression of renal failure in TIN. For successful treatment, early therapeutic intervention should be deployed in selected patients with severe idiopathic TIN.

Adolescent↗
PubMed2003

Possible regulation of the conventional calpain system by skeletal muscle-specific calpain, p94/calpain 3.

p94 (also called calpain 3) is the skeletal muscle-specific calpain and is considered to be a "modulator protease" in various cellular processes. Analysis of p94 at the protein level is an urgent issue because the loss of p94 protease activity causes limb-girdle muscular dystrophy type 2A. In this study, we enzymatically characterized one alternatively spliced variant of p94, p94:exons 6(-)15(-)16(-) (p94delta), which lacks two of the p94-specific insertion sequences. In contrast to p94, which has hardly been studied enzymatically due to its rapid, thorough, and apparently Ca(2+)-independent autolytic activity, p94delta was stably expressed in COS and insect cells. p94delta showed Ca(2+)-dependent caseinolytic and autolytic activities and an inhibitor spectrum similar to those of the conventional calpains. However, calpastatin did not inhibit p94delta and is a substrate for p94delta, which is consistent with the properties of p94, presenting p94 as a possible regulator of the conventional calpain system. We also established a semi-quantitative fluorescence resonance energy transfer assay using the calpastatin sequence specifically to measure p94 activity. This method detects the activity of COS-expressed p94 and p94delta, suggesting that it has potential to evaluate p94 activity in vivo and in the diagnosis of limb-girdle muscular dystrophy type 2A.

Alternative Splicing↗
PubMed2003

Expression profiles of pancreatic cancer cell lines infected with antisense K-ras-expressing adenoviral vector.

The point mutations of the K-ras gene occur in as high as 70-90% of the cases with adenocarcinoma of the pancreas and apparently represent one of the key and early events in the carcinogenesis. However, the specific influence of the K-ras activation on global gene expression profiles in pancreatic cancer cells has not been elucidated. In this study, to promote elucidation of the K-ras-triggered molecular cascade(s) in pancreatic cancer, four pancreatic cancer cell lines with K-ras point mutations were infected with an adenovirus vector expressing an antisense K-ras RNA (AxCA-AS), and the change of gene expression was analyzed by oligonucleotide-based microarrays containing 12,626 genes. Among the genes showing more than 2-fold differences in the expression levels between the control- and antisense-K-ras-transduced cells, 7 genes were commonly up-regulated and 4 genes were commonly down-regulated in three or all of the four pancreatic cancer cell lines transduced with AxCA-AS. The altered gene expression levels observed by microarrays were confirmed by real-time RT-PCR methods. Then, the expression of the 4 down-regulated genes was examined in the untransduced surgical specimens of pancreatic cancer. The G-protein coupled receptor RE2 and phenylethanolamine N-methyltransferase had negligible expression levels in all pancreatic cancers, whereas the syntaxin 1A and p120 catenin isoform were significantly up-regulated in pancreatic cancers containing K-ras mutations compared with a pancreatic cancer with wild type K-ras gene. The transcriptional regulation of those genes may be a part of the molecular cascades triggered by K-ras activation leading to the development and/or progression of pancreatic cancer.

Adenoviridae↗