Biomedical subjects

M Takayama

Publications and source records attributed to M Takayama.

At least 55 records · Page 3Linked to original sources

PubMed2000

Novel assay for measuring serum conjugated bilirubin and its clinical relevance.

We have developed a new enzymatic assay for the determination of conjugated bilirubin (Bc) using stable liquid reagents. In this assay, only Bc is selectively oxidized by bilirubin oxidase at pH 5. 0 in the presence of nitrilotris (methylenephosphonic acid) trisodium salt, ethylenediaminetetraacetic acid disodium manganese (II) salt, and 4-hydroxy-2,2,6,6,-tetramethylpiperidine 1-oxyl. Bc is quantitatively determined from a decrease in the absorbance at 450 nm caused by Bc oxidization. The reagent solutions of the assay were developed so that they could be stably stored for one year together with bilirubin oxidase, in order to eliminate the need to prepare working solutions every time they are required. The assay has good reactivity, differentiability, measurability, and precision. Neither ascorbic acid nor hemoglobin interfered with the measurement. Bc values determined by the assay reflected more clearly the pathophysiological condition of hepatobiliary disease patients with jaundice than the values of total bilirubin or direct bilirubin determined by conventional methods. From these observations, we concluded that this Bc assay is valuable for the evaluation of jaundice.

Bilirubin↗

PubMed2000

[Toxoplasma pericarditis without immunosuppressant disorder detected by polymerase chain reaction of pericardial fluid: a case report].

There have been several case reports, a total of 22 up to the present, of toxoplasma pericarditis. Out of them, in only a few cases the diagnosis was properly made with a proof of the microscopic presence of Toxoplasma gondii. This is the first report of toxoplasma pericarditis in which the presence of Toxoplasma gondii was detected by polymerase chain reaction of pericardial effusion. In addition, the previous reports will be reviewed, and compared to this present case. A 29-year-old woman, without immunosuppressant disorder, suffering from fever and orthopnea was admitted to our hospital. Blood chemistry findings indicated mild liver dysfunction and inflammation. Chest radiography showed cardiac enlargement. Electrocardiography showed sinus tachycardia and ST elevation. Echocardiography revealed a massive pericardial effusion. Pericardiocentesis demonstrated 638 ml of bloody fluid. Cytologic study of the fluid was class II for malignancy, and polymerase chain reaction to tuberculosis was negative. However, a high titer of the anti-toxoplasma antibody of 1: 20,480 (passive hemagglutination) indicated pericarditis caused by Toxoplasma gondii. Subsequently, Toxoplasma gondii was identified in the pericardial effusion by polymerase chain reaction. Clinical symptoms improved after pericardiocentesis, but 2 months later pericarditis recurred. Treatment was started with 800 mg acetylspiramycin daily but failed to improve the symptoms. Because of the development of pleuritis, treatment was changed to sulfadoxine 1,000 mg/pyrimethamine 50 mg. After the treatment with them, her symptoms improved. Only 22 cases of toxoplasma pericarditis have been reported worldwide and 15 of those cases were without immunosuppressant disorder. The usual symptoms at the onset of pericarditis without immunosuppressant disorder are fever, dyspnea and chest pain. Seven patients developed cardiac tamponade. Pericardiocentesis was performed in 8 cases and the pericardial fluid was hemorrhagic in 6. Pericardial thickening was detected in 5 cases. The diagnosis of toxoplasma infection is very difficult, because asymptomatic infection of Toxoplasma gondii is very common. Pericarditis is a disease difficult to confirm the etiology. Detection of Toxoplasma gondii in pericardial effusion by the polymerase chain reaction is very useful for its diagnosis.

Adult↗

PubMed2000

[A pilot trial of high dose CEP (cyclophosphamide, epirubicin, cis-platinum) therapy in patients with advanced and recurrent ovarian cancer].

We evaluated the feasibility of high-dose CEP (cyclophosphamide 750 mg/m2, epirubicin 90 mg/m2, cis-platinum 70 mg/m2) therapy, with granulocyte colony-stimulating factor support every 21 days, in 18 patients with advanced and recurrent ovarian cancer. Ten patients (56%) received 6 cycles of this regimen as planned. Toxicities more than grade 3/4 on' the WHO scale of neutropenia and thrombocytopenia were observed in all cases. Nausea, vomiting, mucositis, malaise, alopecia, hepatotoxicity, and fever were common adverse effects. The average relative dose intensity of cyclophosphamide, epirubicin, cis-platinum was 0.77, 0.77, 0.79 respectively, and each RDI decreased in the last two cycles. These data suggest that this regimen could be performed safely with careful consideration on hepatotoxicity and thrombocytopenia.

Adult↗

PubMed2000

[Clinical significance of pressure measurement in the infarct-related coronary artery in acute myocardial infarction: evaluation of variables predicting recovery of left ventricular function in the convalescent stage].

Early reperfusion and good antegrade flow are essential in restoring better regional left ventricular function in acute myocardial infarction, but they do not always correlate with the extent of recovery. This study evaluated coronary circulation using the new "pressure wire" technique to measure the direct pressure of the coronary circulation including antegrade and collateral flow before and after reperfusion in patients with acute myocardial infarction, and to clarify the influence of these variables on recovery of left ventricular function in the convalescent stage. Fifty six consecutive patients with first acute myocardial infarction underwent percutaneous transluminal coronary angioplasty(PTCA) for totally occluded or severely narrowed infarct-related lesion and evaluation of coronary circulation using pressure wire. Left ventriculography was analyzed at 1 month after the onset in 41 patients. Treatment variables including reperfusion time, reperfusion modality, Thrombolysis in Myocardial Infarction(TIMI) grade after PTCA, and pressure wire variables were compared with parameters of left ventricular function. Reperfusion time was not related to regional wall motion evaluated by the SD chord of left ventriculography in the infarcted zone. Pressure wire measurements showed a correlation between fractional flow reserve measured after PTCA and infarcted regional wall motion(r = 0.558, p < 0.01). Patients with infarct-related lesion in the right coronary artery showed the magnitude of left ventricular regional wall motion was related to fractional collateral flow reserve(maxQc/Qn) during PTCA(r = 0.768, p < 0.05), but no such relationship was observed in patients with infarct-related lesion in the left anterior descending artery. Fractional flow reserve measured after PTCA varied widely in patients with the same TIMI flow grade, so did not vary with it. The pressure wire technique enables assessment of the collateral circulation distal to infarct-related lesion quantitatively before reperfusion in patients with acute myocardial infarction. The fractional flow reserve derived by coronary pressure after reperfusion was significantly related to the recovery of regional wall motion in the infarcted area in the convalescent stage. The fractional flow reserve after reperfusion with PTCA is a better parameter than TIMI flow grade for predicting recovery of regional left ventricular function after myocardial infarction.

Angioplasty, Balloon, Coronary↗

PubMed2000

[Study on evaluation method of patient dose in diagnostic radiology required for introducing the guidance level: investigation of entrance surface dose of patient using direct measurement by TLD].

Using direct measurement, we investigated entrance surface doses of patients for routine radiographs in attempt to develop evaluation methods of patient dose in order to establish the guidance level in Japan. To date, patient doses have been evaluated by calculations based on radiographic conditions, or model experiments using phantoms. Their patient doses are then evaluated based on several assumptions. Direct measurement of patient dose is difficult to perform in many patients due to its time requirement, level of expertise required and difficulty in providing an explanation of the procedure to the patient. However, such direct measurement is essential since it incorporates all aspects of radiography from the radiographic equipment used, to the actual conditions of each patient without assumption. In this study, we examined the (1) need for introducing the guidance level, (2) controversial points in the calculation method for patient dose evaluation, (3) evaluation accuracy required for introducing the guidance level, and (4) necessity for a standardized method.

Guidelines as Topic↗

PubMed2000

Clinical factors related to the aqueous levels of vascular endothelial growth factor and hepatocyte growth factor in proliferative diabetic retinopathy.

PURPOSE: To investigate clinical factors related to the aqueous humor levels of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in patients with proliferative diabetic retinopathy (PDR). METHODS: Undiluted aqueous humor was obtained during ocular surgery from 46 eyes of 46 patients and the levels of growth factors were measured using enzyme-linked immunosorbent assays. VEGF and HGF levels were compared with the number of photocoagulation. VEGF and HGF levels in patient groups stratified according to the existence of vitreous hemorrhage, retinal detachment, and fibrovascular membrane were analyzed. And clinical parameters associated with the growth factors were determined by multiple regression analysis. RESULTS: The levels of VEGF decreased significantly as the extent of photocoagulation increased and showed significant positive correlation with the existence of vitreous hemorrhage. There was no significant correlation between VEGF levels and the existence of fibrovascular membrane and traction retinal detachment. The levels of HGF also decreased significantly as the extent of photocoagulation increased, but increased significantly when fibrovascular membrane existed. There were no significant correlations between HGF levels and the existence of vitreous hemorrhage and traction retinal detachment. Concerning systemic conditions, each growth factor has no significant correlation with duration and type of diabetes mellitus, the treatment regimen, the control of hemoglobin A1C, and the existence of hypertension or renal dysfunction. CONCLUSION: The therapeutic effect of panretinal photocoagulation on PDR might be partly exerted by reduction of the levels of VEGF and HGF in ocular fluid. Since the clinical parameters associated with VEGF were different from those associated with HGF, these growth factors might influence the progression of retinopathy in different ways.

Adult↗

PubMed2000

[A case of MPO ANCA associated glomerulonephritis with interstitial pneumonitis complicated with lung tuberculosis and pericarditis].

The main target organs of myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA)-related disease are the kidney and lung. This report describes a 71-year-old man with rapidly progressive glomerulonephritis (RPGN) and interstitial pneumonitis associated with MPO ANCA. The patient was admitted to our hospital because of bloody sputum, low grade fever and appetite loss on October, 1998. He was diagnosed as having interstitial pneumonitis from the findings of chest X-ray and CT examinations. Moderate proteinuria and hematuria, renal dysfunction(serum creatinine: 5.6 mg/dl, BUN: 58.0 mg/dl) and positivity for MPO ANCA were noted. He was negative for anti-glomerular antibody and PR3-ANCA. Renal biopsy was performed and revealed crescentic glomerulonephritis without deposition of immunoglobulins. Therefore, the diagnosis of pauci immune type RPGN was made. Pulse therapy with methylprednisolone(1.0 g/day x 3 days) following oral administration of prednisolone (60 mg/day) found marked improvement of renal function maintenance and interstitial pneumonitis, respectively. However, he died because of lung tuberculosis and acute tuberculous pericarditis during treatment with prednisolone. In this case, MPO ANCA might have been directly associated with both RPGN and interstitial pneumonitis. Furthermore, chronic lung disease, such as interstitial pneumonitis, is important as a preceding disease of RPGN. MPO ANCA-related disease is more frequent in aged persons, therefore particular attention should be paid during their treatment with an immunosuppressant.

Aged↗

PubMed2000

The role of cytokine-induced neutrophil chemoattractant-1 in neutrophil-mediated remote lung injury after intestinal ischaemia/reperfusion in rats.

OBJECTIVE: Remote lung injury is induced by ischaemia/reperfusion (I/R) of the gastrointestinal tract and the liver following hypovolaemic shock. In the present study, the role of cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin (IL)-8 family, in neutrophil-mediated remote lung injury following intestinal I/R was investigated in anaesthetized rats. METHODOLOGY: The I/R group was subjected to 60 min of occlusion of the superior mesenteric artery with laparotomy, followed by 240 min of intestinal reperfusion. The sham-operated (sham) group was subjected to the same procedures with the exception of intestinal I/R. RESULTS: In the I/R group, the permeability index of the lung, the neutrophil count in pulmonary vascular lavage fluid and bronchoalveolar lavage fluid (BALF), lung myeloperoxidase activity and neutrophil oxidative production were all significantly greater than those in the sham group. Cytokine-induced neutrophil chemoattractant-1 levels in blood and BALF were significantly increased at 240 min after intestinal reperfusion. There was a significant relationship between neutrophils in BALF and CINC-1 level in BALE CONCLUSION: These findings suggest that intestinal reperfusion was associated with activation and accumulation of neutrophils in the lung and resulted in remote lung injury with increased microvascular permeability. Thus, CINC-1 in BALF may induce neutrophil migration from the pulmonary vessels to the interstitium and alveolar spaces in remote lung injury after intestinal I/R.

Animals↗

PubMed1999

Characterization of the human dihydropyrimidinase-related protein 2 (DRP-2) gene.

The genes within the dihydropyrimidinase-related protein (DRP) family, were originally identified in humans by their homology to dihydropyrimidinase (DHP). Four members of this gene family, DRP-1, -2, -3 and -4, are expressed mainly in the fetal and neonatal brains of mammals and chickens, and have been implicated as intracellular signal transducers in the development of the nervous system. We isolated the human DRP-2 gene, and determined its transcriptional start site and exon/intron organization. The gene spanned more than 62 kb, and contained 14 exons with lengths ranging from 62 bp to 2606 bp. The transcriptional start site was determined by an RNase protection assay and 5' rapid amplification of cDNA ends (RACE), and a highly GC-rich promoter was identified that contained possible regulatory elements such as a TATA box, CAAT box and three GC boxes. Comparison of the phase and position of intron insertions within the human DRP-2 gene with those within DRP-1, DHP and two Caenorhabditis elegans DRP/DHP homologs, indicated that DRPs are more conserved in their exon/intron organization than DHP.

Amidohydrolases↗

PubMed1999

Involvement of nitric oxide in aminoglycoside vestibulotoxicity in guinea pigs.

Involvement of nitric oxide (NO) has been reported in physiological and pathological conditions in the inner ear. Recently, the presence of nitric oxide synthase (NOS) was demonstrated in the vestibular epithelium. In this study we used nicotinamide adenine dinucleotide phosphate-diapholase staining to monitor NOS activity during degeneration of guinea pig vestibular epithelia affected by streptomycin. Increased NOS activity was observed in affected epithelia in a dose- and time-dependent manner and a NOS inhibitor could protect hair cells from apoptosis. Additionally, cycloheximide significantly reduced NOS activity and the occurrence of apoptosis. These findings suggest that NO is involved in the degenerative process of vestibular epithelia caused by aminoglycosides.

Aminoglycosides↗

PubMed1999

Glutamate toxicity induced degeneration of outer hair cells with a temporal increase of nitric oxide production in the guinea pig cochlea.

The aim of this study was to examine the roles of glutamate (GLU) toxicity and involvement of nitric oxide (NO) in the pathogenesis of cochlear degeneration. We examined guinea pig cochleae following chronic exposure to GLU. Trypan blue extrusion and transmission electron microscopy were performed to evaluate degeneration in the organ of Corti. In parallel, nitric oxide synthase (NOS) activity was demonstrated by histochemical staining of NADPH diapholase. GLU treatment caused time-dependent degeneration of outer hair cells (OHCs) in conjunction with a temporal increase of NOS activity in the organ of Corti. This suggests that GLU may be involved in OHC degeneration under toxic conditions, with NO production possibly playing a role in this process.

Animals↗

PubMed1999

Increased heterogeneity of chromosome 17 aneuploidy in endometriosis.

OBJECTIVE: Endometriosis is a complex gynecologic disorder that may display features similar to malignancy, including aggressive growth and localized invasion of the myometrium or spread to various organs outside the uterus. Molecular studies of cancer have demonstrated that genomic instability involving chromosome 17 plays a role in the development and progression of various tumor types. These involve gain and/or loss, deletions, and mutations of candidate tumor suppressor genes (eg, BRCA1 and p53 ) on chromosome 17. STUDY DESIGN: We used a 2-color fluorescence in situ hybridization method for analysis of endometriotic and normal archival tissue. Centromere-specific and locus-specific p53 probes localized to chromosome 17 were selected to study 8 patients with late-stage (severe) endometriosis. Single cells localized to endometriotic lesions or normal endometrial glands were analyzed and identified as normal or abnormal on the basis of the distribution of fluorescence in situ hybridization signals. RESULTS: Overall, chromosome 17 aneuploidy was significantly greater (P <.05) in the endometriosis specimens (mean of 65%) than in normal endometrial cells (mean of 25%). No significant difference (P =.1071) in the distribution of fluorescence in situ hybridization signals was observed among the 5 normal endometrial specimens. However, significant differences (P <. 0001) were observed between the 8 endometriosis tissue specimens. CONCLUSION: We found increased heterogeneity of chromosome 17 aneuploidy in endometriosis. These findings support a multistep pathway involving somatic genetic alterations in the development and progression of this common disease.

Aneuploidy↗

PubMed1999

Loss of protection by hypoxic preconditioning in aging Fischer 344 rat hearts related to myocardial glycogen content and Na+ imbalance.

OBJECTIVES: The objective of this study was to determine whether hypoxic preconditioning (HP) could lessen the myocardial increase in [Na+]i, thus protecting the aging myocardium against ischemia. BACKGROUND: A decrease in ischemic tolerance with aging is associated with an accelerated increase in [Na+]i during ischemia. Ischemic preconditioning fails to protect the middle-aged and senescent myocardium against ischemia. METHODS: Isolated hearts of young adult (12-week-old), middle-aged (50-week-old) and senescent (100-week-old) Fischer 344 rats were subjected to 25 min of ischemia with or without HP followed by 30 min of reperfusion. Left ventricular (LV) function, myocardial energy metabolites and [Na+]i were measured. RESULTS: In the older groups, the recovery of LV function and high-energy phosphates (HEPs) was lower with an increased release of creatine kinase (CK) during reperfusion than in the young group. The increased [Na+]i at the end of ischemia was greater in the former groups than in the young group. HP decreased myocardial glycogen and lessened the increased [Na+]i in the young group, resulting in an improved recovery of LV function and HEPs, as well as decreased CK release. However, the levels of glycogen before HP in the older groups were higher than in the young group and its levels after HP were similar to that before HP in the young group. HP did not affect the [Na+]i, exacerbated CK release and inhibited the recovery of LV function and HEPs in the older groups. CONCLUSIONS: HP failed to lessen the increased [Na+]i or to protect the aging hearts, probably due to the preexistence of increased glycogen level.

Aging↗

PubMed1999

A novel method to produce extensive gastric antral ulcer in rats: pharmacological factors involved in the etiology of antral ulceration.

Gastric antral area is the most susceptible region to gastric ulceration in man. However, only limited information is available on animal models. In the present paper, we have developed an improved method for inducing gastric antral ulcers by the administration of 1.0 M HCl after refeeding for 1 h in rats. On day 4, the severe ulcer was found covering extensively the whole area of the antrum, and penetrated through the muscularis mucosae. The incidence of ulceration was 100% and the mean ulcer index was 37.1 +/- 16.6 mm2. In contrast, none of the erosive lesions were observed in the corpus area. Before 24 h, only slight hyperemia was observed in the antral region, suggesting that some submucosal mechanisms are involved in the ulceration processes other than the direct erosive action of HCl on the mucosal surface. Additional treatment with diethyldithiocarbamate (125 mg x kg(-1), s.c.), superoxide dismutase inhibitor, significantly aggravated this antral ulcer, and the ulcer index was 66.0 +/- 13.6 mm2. Allopurinol (50 mg x kg(-1), p.o.) significantly prevented ulcer formation induced by HCl plus DDC. GSH (150 mg x kg(-1), i.p.) also markedly prevented the ulceration. However, DMSO (0.5%, 5 mL x kg(-1), p.o.) was found not to affect ulcer formation. Famotidine (20 mg x kg(-1), p.o.) almost completely inhibited ulcer formation. From the above results, it was concluded that gastric antral ulcer can be induced by the simple treatment of 1.0 M HCl in refed rats, and the antrum has a different defensive mechanism from that in the corpus area. In addition. oxygen derived radicals, especially superoxide anion and endogenous acid secretion were found to be involved in the etiology of the aggravation of the gastric antral ulcer induced by DDC.

Animals↗

PubMed1999

Expression of telomerase subunits and localization of telomerase activation in hydatidiform mole.

Activation of telomerase compensating for the loss of telomeres has been implicated in human cell immortalization and carcinogenesis. Telomeric repeat amplification protocol (TRAP) assay can be used to detect telomerase activity in a variety of malignant tumours, including those of the female reproductive tract which have been found to have high levels of telomerase activity. However, it is unclear whether all the cells or only a subset of cells within a tumour have telomerase activity. To determine the regulation mechanism of telomerase activity in hydatidiform moles, we studied telomerase activity at the single cell level (using an in situ TRAP assay), and expression of TLP1 (telomerase protein 1), TERC (telomerase RNA component) and TERT (telomerase reverse transcriptase component). Expression of TERC and TLP1 was observed in all normal chorionic villi, as well as in trophoblastic diseases, and various cell lines irrespective of telomerase activity. TERT expression was observed in trophoblastic diseases and normal chorionic villi with telomerase activity but not in normal chorionic villi without telomerase activity, except in some cases in the present series, indicating that TERT expression is closely associated with telomerase activity. Upregulation of TERT expression may thus play an important role in telomerase reactivation.

Carrier Proteins↗

PubMed1999

Cystine protects cochlear outer hair cells against glutamate toxicity.

We previously reported that long-term exposure to glutamate (Glu) induced death of cochlear outer hair cells (OHCs). However, the mechanisms of OHC death induced by Glu were unclear. In the central nervous system, Glu is known to interfere with a cystine-Glu antiporter, leading to a decrease in cystine uptake and reducing the intracellular glutathione level. We therefore investigated the effect of cystine supplementation on degeneration of OHCs caused by long-term exposure to Glu. Supplementation of cystine significantly decreased the number of dying OHCs. These findings suggest that a cystine-Glu interaction may be involved in the mechanism of OHC degeneration caused by Glu.

Analysis of Variance↗

PubMed1999

Nuclear transport of the major capsid protein is essential for adeno-associated virus capsid formation.

Adeno-associated virus capsids are composed of three proteins, VP1, VP2, and VP3. Although VP1 is necessary for viral infection, it is not essential for capsid formation. The other capsid proteins, VP2 and VP3, are sufficient for capsid formation, but the functional roles of each protein are still not well understood. By analyzing a series of deletion mutants of VP2, we identified a region necessary for nuclear transfer of VP2 and found that the efficiency of nuclear localization of the capsid proteins and the efficiency of virus-like particle (VLP) formation correlated well. To confirm the importance of the nuclear localization of the capsid proteins, we fused the nuclear localization signal of simian virus 40 large T antigen to VP3 protein. We show that this fusion protein could form VLP, indicating that the VP2-specific region located on the N-terminal side of the protein is not structurally required. This finding suggests that VP3 has sufficient information for VLP formation and that VP2 is necessary only for nuclear transfer of the capsid proteins.

Amino Acid Sequence↗

PubMed1999

Comparison of the levels of hepatocyte growth factor and vascular endothelial growth factor in aqueous fluid and serum with grades of retinopathy in patients with diabetes mellitus.

AIMS: To determine the relation between the stages of diabetic retinopathy (DR) and the levels of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) in aqueous fluid and serum. METHODS: Levels of HGF and VEGF in serum and aqueous humour obtained during ocular surgery were measured by enzyme linked immunosorbent assay in 58 diabetic patients with 32 non-diabetic patients (NDM) as controls. The patients with diabetes were classified into three groups according to the stage of DR: no DR (NDR; 15 cases), non-proliferative DR (NPDR; six cases), and proliferative DR (PDR; 37 cases). RESULTS: No significant differences were found between any of the groups in serum concentrations of HGF or VEGF. The aqueous HGF levels increased with the stage of DR: NDM, median 397 pg/ml, range 133-930 pg/ml; NDR, 371 pg/ml, 142-1536 pg/ml; NPDR, 455 pg/ml, 162-1007 pg/ml; and PDR, 638 pg/ml, 187-2222 pg/ml. The aqueous VEGF levels in PDR (median 212 pg/ml, range 14-1216 pg/ml) were significantly higher than in NDM (105 pg/ml, 9-203 pg/ml), but aqueous HGF concentrations were unrelated to those of VEGF. CONCLUSION: The results of the present study suggest that both HGF and VEGF present in the ocular tissues may play important roles in the progression of DR.

Adult↗