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Biomedical subjects

H Ito

Publications and source records attributed to H Ito.

At least 271 records · Page 15Linked to original sources
PubMed2001

Prediction of wall motion recovery from the left anterior descending coronary artery velocity pattern recorded by transthoracic doppler echocardiography in patients with anterior wall myocardial infarction retrospective and prospective studies.

The diastolic deceleration slope of coronary flow velocity is steeper in patients with substantial 'no reflow' phenomenon than in those without it. This study investigated whether functional outcomes in patients with anterior wall acute myocardial infarction (AMI) can be predicted by analyzing the coronary flow velocity pattern recorded with transthoracic Doppler (TTD) echocardiography. Coronary blood flow velocity in the distal left anterior descending coronary artery was recorded with TTD at day-2 after primary percutaneous transluminal coronary angioplasty/Stent in 51 patients with anterior AMI and the diastolic deceleration half time (DHT, ms) was measured. The wall motion score index (WMSI) was measured at day-1 and -21. In the retrospective study, the DHT was much shorter in those with a poor outcome than in those with good outcome (152 +/- 109 vs 395 +/- 128 ms, p<0.05). Receiver-operating characteristic analysis documented that DHT > or = 300 ms is a suitable cut-off point (sensitivity of 83% and specificity of 93%). In the prospective study (n=30), AWMSI(dl-d21) was significantly higher in those with a DHT > or = 300 ms than those without (0.3 > or = 0.5 vs 1.6 > or = 0.7, p<0.001). DHT correlated significantly with AWMSI(dl-d21) (r=0.76, p<0.001). Patients with a shorter DHT of diastolic coronary flow velocity have a poorer functional outcome among patients with anterior AMI. The TTD-determined DHT is a useful predictor of myocardial viability after an anterior AMI.

Adult↗
PubMed2001

Detection of nasopharyngeal carcinoma: fast short time inversion recovery images compared with fat suppression, contrast enhanced T(1) weighted spin echo images.

The aim was to compare fast short time inversion recovery (FSTIR) images and fat suppression, contrast enhanced T(1) weighted (FSCE T1W) spin echo images in the diagnosis of nasopharyngeal carcinoma (NPC). 102 MR studies were obtained with a 1.0 T or a 1.5 T system in 28 patients with NPC. The MR studies comprised both FSTIR and FSCE T1W images. FSTIR and FSCE T1W images were compared for detection of NPC by means of a receiver operating characteristic (ROC) analysis. The areas under the ROC curves of FSTIR and FSCE T1W images showed no statistical difference (0.87 vs 0.87). There was also no statistical difference in the sensitivity, specificity and accuracy of each sequence (0.74 vs 0.77, 0.81 vs 0.77 and 0.79 vs 0.77, respectively). Both sequences had the same performance for detection of NPC. FSTIR is as useful as FSCE T1W images, especially in the detection of recurrent tumours, but without the cost of contrast medium.

Adult↗
PubMed2001

Major isoforms of starch branching enzymes in premature seeds of kidney bean (Phaseolus vulgaris L.).

Developing seeds of the kidney bean (Phaseolus vulgaris L.) contain several isoforms of starch branching enzymes. Two of them, KBE1 and KBE2, which are the major forms in the premature seeds, were purified as a single band of protein on SDS-PAGE and native PAGE by chromatographies on DEAE-Sepharose, Bio-Gel P-200, and amylose-binding Sepharose 6B. The enzymes had similar pH optimum (7.0), pH stability (7.0-9.5), temperature optimum (25-30 degrees C), and temperature stability (up to 40 degrees C). Additionally, both were inhibited by various divalent metal ions and activated by citrate. Finally, though their N-terminal amino acid sequences were identical, their molecular masses and affinities for amylose differed; 80 kDa and 1.27 mM for KBE1 and 77 kDa and 0.74 mM for KBE2.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2001

1-Aminocyclopropane-1-carboxylate synthase of Penicillium citrinum: primary structure and expression in Escherichia coli and Saccharomyces cerevisiae.

A plant hormone, ethylene, is formed through 1-aminocyclopropane-1-carboxylic acid (ACC). A fungus, Penicillium citrinum, was found to synthesize ACC and to degrade ACC into 2-oxobutyrate and ammonia. ACC synthase, responsible for ACC synthesis in P. citrinum, was characterized on the molecular level by sequencing of N terminal and proteolytic peptides of the enzyme, and cloning and sequencing of its cDNA. The ACC synthase from P. citrinum had 430 amino acid residues and a shorter C terminal than the plant enzyme. The enzyme purified from Escherichia coli transformed with ACC-synthase-encoding DNA showed similar properties to those of the purified enzyme from P. citrinum. Saccharomyces cerevisiae with ACC synthase accumulated ACC in the medium with increasing time of incubation. The sequence of ACC synthase from P. citrinum was compared with that of the plant enzyme with discussion about important residues for catalysis.

Amino Acid Sequence↗
PubMed2001

The efficacy of ununited tibial fracture treatment using pulsing electromagnetic fields: relation to biological activity on nonunion bone ends.

Thirty ununited tibial fractures with a median time since injury of 18+/-9 months were treated by electrical stimulation using pulsing electromagnetic field therapy. Union was achieved in 25 cases (83.3%) in a median interval of 8.6+/-3.2 months. Patient age and gender, the presence of surgical hardware, length of disability, and the number of surgical procedures did not affect the outcome. Ununited fractures that appeared to be hypertrophic or sclerotic type radiographically, indicating a good blood supply to the bone ends, all healed. Treatment failures occurred only among lesions with a poor blood supply, and in necrotic or defective radiopraphic types. Pulsing electromagnetic field therapy is an effective treatment for ununited tibial fractures with good blood supply to the bone ends.

Adult↗
PubMed2001

Protein kinase inhibitors can suppress stress-induced dissociation of Hsp27.

We previously showed that the aggregated form of Hsp27 in cultured cells becomes dissociated as a result of phosphorylation with various types of stress. In order to clarify the signal transduction cascade involved, the effects of various inhibitors of protein kinases and dithiothreitol on the dissociation of Hsp27 were here examined by means of an immunoassay after fractionation of cell extracts by sucrose density gradient centrifugation. The dissociation of Hsp27 induced by exposure of U251 MG human glioma cells to metals (NaAsO2 and CdCl2), hypertonic stress (sorbitol and NaCI), or anisomycin, an activator of p38 mitogen-activated protein (MAP) kinase, was completely suppressed by the presence of SB 203580 or PD 169316, inhibitors of p38 MAP kinase, but not by PD 98059 and Uo 126, inhibitors of MAP kinase kinase (MEK), nor by staurosporine, Go 6983, and bisindolylmaleimide I, inhibitors of protein kinase C. Phorbol ester (PMA)-induced dissociation of Hsp27 was completely suppressed by staurosporine, Go 6983, or bisindolylmaleimide I and partially suppressed by SB 203580, or PD 169316 but not by PD 98059 or Uo 126, indicating mediation by 2 cascades. The presence of 1 mM dithiothreitol in the culture medium during exposure to chemicals suppressed the dissociation of Hsp27 induced by arsenite and CdCl2 but not by other chemicals. These results suggest that the phosphorylation of Hsp27 is catalyzed by 2 protein kinases, p38 MAP kinase-activated protein (MAPKAP) kinase-2/3 and protein kinase C. In addition, metal-induced signals are sensitive to reducing power.

Anisomycin↗
PubMed2001

Pretreatment serum level of testosterone as a prognostic factor in Japanese men with hormonally treated stage D2 prostate cancer.

Pretreatment serum level of testosterone (T) is a potential prognostic factor for prostate cancer. However, T levels in Japanese prostate cancer patients are unknown to date. To evaluate the clinical significance of pretreatment serum T level in such patients, serum T level was analyzed in relation to several clinical factors in a total of 130 patients with various stages of prostate cancer, 74 of whom had metastatic disease (stage D2) and received endocrine therapy as first-line treatment. The mean pretreatment T level in patients with non-metastatic prostate cancer (stages B + C) was significantly lower than that in stage D2 patients (B + C: 4.05 +/- 2.01 ng/ml; D2: 4.85 +/- 2.18 ng/ml, p = 0.0344). On the other hand, the mean serum level of T was higher in stage D2 patients who showed good response to endocrine therapy (CR: 5.42 +/- 1.55 ng/ml; non-CR: 4.30 +/- 2.63 ng/ml, p = 0.0320). When the 74 stage D2 patients were divided into high and low T level groups according to the median value, those patients with a high T level had significantly better cause-specific and progression-free survival. Multivariate analysis demonstrated that extent of bone metastases (EOD) grade, pretreatment serum T level and tumor marker response to endocrine therapy were significant predictors for progression-free survival. In conclusion, a higher pretreatment T level appears to be predictive of the marker response to endocrine therapy, showing positive prognostic value and indicating good prognosis in patients at the metastatic stage. However, a higher T level was also associated with stage progression of this disease.

Aged↗
PubMed2001

Effects of increased physical activity and mild calorie restriction on heart rate variability in obese women.

The effects of exercise and mild calorie restriction on heart rate variability (HRV) were investigated in 12 mildly obese, normotensive Japanese women aged 45.8+/-4.2 (SEM) years with a body mass index (BMI) of 27.3+/-0.4 kg/m2. The subjects participated in a 3-month program aimed at increasing physical activity and modifying eating behavior (intervention group). The control group consisted of 12 women (age 50.1+/-4.8 years, BMI 27.2+/-0.6 kg/m2) who did not attend the program. The frequency domain of HRV was calculated from 5-min Holter recordings while the subjects rested in a supine position. After 3 months, BMI decreased to 25.0+/-0.5 kg/m2 (p<0.001 vs baseline) in the intervention group, which was accompanied by decreases in body fat mass, waist circumference, serum total cholesterol and triglycerides, and improvement in insulin sensitivity. The mean and SD of the RR intervals, total power, and low and high frequency power of HRV significantly increased after the intervention, whereas no significant changes were seen for the controls. The changes in these HRV variables (calculated by subtracting the baseline values from the follow-up values) negatively correlated with the change in waist circumference, with the Pearson correlation coefficients being between -0.50 and -0.62 (p<0.05). A negative correlation was also seen between the changes in high frequency power and insulin resistance estimated by homeostasis model assessment (r=-0.49, p<0.05). The combination of exercise and mild calorie restriction led to changes in HRV indicative of an improvement in parasympathetic modulation.

Body Mass Index↗
PubMed2001

Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts.

We reported previously that exposure of normal human fibroblasts in G2 phase of the cell cycle to high-LET radiation produces a much higher frequency of isochromatid breaks than exposure to gamma rays. We concluded that an increase in the production of isochromatid breaks is a signature of initial high-LET radiation-induced G2-phase damage. In this paper, we report the repair kinetics of isochromatid breaks induced by high-LET radiation in normal G2-phase human fibroblasts. Exponentially growing human fibroblasts (AG1522) were irradiated with gamma rays or energetic carbon (290 MeV/nucleon), silicon (490 MeV/nucleon), or iron (200 MeV/nucleon) ions. Prematurely condensed chromosomes were induced by calyculin A after different postirradiation incubation times ranging from 0 to 600 min. Chromosomes were stained with Giemsa, and aberrations were scored in cells at G2 phase. G2-phase fragments, the result of the induction of isochromatid breaks, decreased quickly with incubation time. The curve for the kinetics of the rejoining of chromatid-type breaks showed a slight upward curvature with time after exposure to 440 keV/microm iron particles, probably due to isochromatid-isochromatid break rejoining. The formation of chromatid exchanges after exposure to high-LET radiation therefore appears to be underestimated, because isochromatid-isochromatid exchanges cannot be detected. Increased induction of isochromatid breaks and rejoining of isochromatid breaks affect the overall kinetics of chromatid-type break rejoining after exposure to high-LET radiation.

Cells, Cultured↗
PubMed2001

Tobacco smoking and neutrophil activity in patients with periodontal disease.

BACKGROUND: Tobacco smoking has considerable negative effects on periodontal health. The mechanisms behind these effects are incompletely understood but may be related to the host response. The aim of the present study was to investigate the influence of tobacco smoking on the gingival crevicular fluid (GCF) levels of elastase, lactoferrin (LF), alpha-1-antitrypsin (alpha-1-AT), and alpha-2-macroglobulin (alpha-2-MG) under periodontally diseased conditions. METHODS: The study population included 15 smokers (5 women and 10 men) aged 34 to 69 years and 17 non-smokers (5 women and 12 men) aged 31 to 81 years. Clinical registration of gingival index (GI), plaque index (PI), probing depth, as well as sampling of GCF were made at 3 sites with severe lesions and 3 sites with moderate lesions in each individual. The elastase activity was measured with a chromogenic low molecular substrate and the LF, alpha-1-AT, and alpha-2-MG concentrations with ELISA. RESULTS: The results showed that, with regard to severe lesions, smokers had a significantly lower concentration of alpha-2-MG as well as significantly lower total amounts of alpha-2-MG and alpha-1-AT than non-smokers. With regard to moderate lesions, smokers tended to exhibit a lower concentration of alpha-2-MG, but the difference was not statistically significant. Comparing moderate and severe lesions, smokers exhibited no gradual increase with disease severity in contrast to non-smokers, who showed significantly or almost significantly increased levels of LF and alpha-2-MG in severe as compared to moderate lesions. CONCLUSIONS: The present results indicate that the levels of alpha-2-MG and alpha-1-AT are suppressed in smokers with periodontitis, suggesting that smoking interferes with these protease inhibitors. This may be one mechanism by which smoking affects the inflammatory response.

Adult↗
PubMed2001

Potential of microvascular reperfusion with adjunctive pharmacological intervention: its impact on myocardial perfusion and functional outcomes in patients with acute myocardial infarction.

One of the major limitations of reperfusion therapy in acute myocardial infarction (AMI) is the presentation of no-reflow phenomenon. In 25 to 30% of patients with AMI. myocardial blood flow is occasionally profoundly reduced, even after coronary recanalisation, because of microvascular dysfunction so-called no-reflow phenomenon. Patients with this phenomenon are regarded as a high risk group among patients with reperfused AMI. Clinical studies using myocardial contrast echocardiography have demonstrated that intracoronary injection of calcium antagonists or potassium channel agonists in conjunction with coronary reperfusion can augment myocardial blood flow and that this was associated with better functional and clinical outcomes than with percutaneous transluminal coronary angioplasty alone. Thus, it is possible to prevent reperfusion injury and improve cardiac function using a adjunctive pharmacological intervention, either intravenously or by infusion directly into the coronary artery.

Angioplasty, Balloon, Coronary↗
PubMed2001

Semiquantitative measurement of acetylcholine receptor at the motor end-plate in myasthenia gravis.

OBJECTIVE: The purpose of this study was to investigate whether this semiquantitative measurement of the motor end-plate acetylcholine receptors (AChRs) can be used to confirm the diagnosis of myasthenia gravis (MG), and in particular ocular MG. METHODS: Motor point biopsies were performed from the biceps brachii muscles. Measurement of AChRs was made in peroxidase-labeled alpha-bungarotoxin stained muscle specimens. PATIENTS: Twenty patients with ocular MG, 37 with generalized MG, 5 with Lambert-Eaton myasthenic syndrome, 3 with botulism, 8 with amyotrophic lateral sclerosis, and 8 controls were included in this study. RESULTS: AChRs were decreased in all patients with generalized MG and in 80% of ocular MG including patients without detectable circulating anti-AChR antibodies, as compared with the control subjects. CONCLUSION: This method is useful to confirm the diagnosis of MG, in particular ocular MG without detectable anti-AChR antibodies.

Adolescent↗
PubMed2001

Long-term prognosis after recovery from myocardial infarction: a community-based survey in Yamagata, Japan.

OBJECTIVE: To assess the long-term prognosis after recovery from acute myocardial infarction (AMI) in the general population in Japan. PATIENTS AND METHODS: Among the 575,000 inhabitants of the Yamagata metropolitan area, a total of 117 patients suffered from first their AMI from April to December 1993. Thirteen patients (11%) died within four weeks after the onset. Of the remaining 104 patients, 101 (mean age, 69+/-12 years) were followed for an average of 65+/-5 months. RESULTS: Twenty-seven of the 101 patients (27%) died during the follow-up period. Compared with survivors, the patients who died were significantly older at the onset of AMI (74+/-12 vs. 67+/-12 years, p<0.01). More diabetic patients than non-diabetic patients died (42 vs. 21%, p<0.05) because of the higher frequency of non-cardiac deaths (29 vs. 11%, p<0.05). The total number of deaths of cardiac origin, including sudden deaths, was 11 (40%) and was lower than the number of definite non-cardiac deaths (n=15). The time from the onset of AMI to death was significantly shorter in cases of cardiac death than in cases of non-cardiac death (median, 16 vs. 45 months, p<0.01). Among non-cardiac deaths, deaths due to lung cancer and cerebral infarction were notable in men (standardized mortality ratio 278) and women (571), respectively. CONCLUSION: Non-cardiac death during long-term follow-up after AMI was more frequent than death of cardiac origin. Thus, preventive measures, including early treatment of complicating diseases, must be implemented to improve the long-term prognosis of patients with myocardial infarction.

Age Factors↗
PubMed2001

Cerebral amyloid angiopathy associated with hemorrhage: immunohistochemical study of 41 biopsy cases.

The relationship between cerebral amyloid angiopathy and hemorrhage was investigated by an immunohistochemical study of biopsy cases to characterize the involvement of amyloid beta-protein, apolipoprotein E, and cystatin C in cerebral amyloid angiopathy associated with hemorrhage. The amyloid-laden vessels were examined in biopsy specimens from 41 surgical cases of sporadic cerebral amyloid angiopathy (36 cases with hemorrhage and 5 cases without hemorrhage), using immunohistochemical staining with antibodies against amyloid beta-protein, apolipoprotein E, cystatin C, and alpha-smooth muscle actin. The relationship between the occurrence, recurrence, and enlargement of the hemorrhage, and the semiquantitative estimation of the cerebrovascular amyloid-related protein deposition was analyzed using Fisher's exact test. Severe amyloid beta-protein (p < 0.013) and apolipoprotein E (p < 0.013) immunoreactivity were risk factors for the occurrence of the hemorrhage. Severe cystatin C immunoreactivity was a risk factor for the occurrence (p < 0.002) and enlargement (p < 0.014) of the hemorrhage, and tended to induce recurrent hemorrhage (p < 0.103). In addition, loss of the vascular smooth muscle was observed in the intensely amyloid-laden vascular walls that showed cystatin C-immunoreactivity. The present study indicates that intense amyloid beta-protein deposition with cystatin C deposition weakens the cerebrovascular walls, and that cystatin C deposition is a strong predictor of hemorrhage in cerebral amyloid angiopathy.

Aged↗
PubMed2001

Immunoglobulin heavy chain variable region (VH) genes of B cell chronic lymphocytic leukemia cells from lymph nodes show somatic mutations and intraclonal diversity irrespective of follicular dendritic cell network.

We analyzed the immunoglobulin heavy chain variable region (VH) gene in 4 Japanese cases of B cell chronic lymphocytic leukemia (B-CLL) with enlarged lymph nodes to clarify the presence of somatic mutations and intraclonal diversity. We also attempted to determine the role of the follicular dendritic cell (FDC) network in some proliferation centers, where tumor cells are mitotically active. Immunohistochemical studies revealed that all 4 cases showed the typical immunophenotype: CD5+, CD23+, IgM+ and IgD+. DNA was extracted from paraffin sections (lymph node) and rearranged VH gene was amplified by PCR. All but one exhibited a moderate number of somatic mutations, with percentages ranging from 4.1 to 9.5, and one of which indicated the effect of antigen selection on its VH gene. Multiple clone analysis of whole tissues showed intraclonal diversity in one case, whose VH gene carried a somatic mutation but the effect of antigen selection was not apparent. We further examined microdissected tissues to elucidate the relationship between FDC network and VH gene status in 2 cases. In one case, intraclonal diversity was not apparent irrespective of FDC network, however, both tumor cells around the FDC network and those apart from the FDC showed signs of intraclonal diversity in another case, suggesting that intraclonal diversity was not related to the FDC network in B-CLL. Here we demonstrate that some cases of B-CLL involved in lymph node carried mutated VH genes and showed intraclonal diversity like the tumor cells in the peripheral blood. However, the significance of the FDC network in the proliferation center still remains to be resolved.

Amino Acid Sequence↗
PubMed2001

Cell killing and mutation induction by heavy ion beams.

Carbon beam radiotherapy for cancer patients was initiated in Japan in June 1994. This study attempts to clarify the radiobiological effects of heavy ion beams. In this study, human cancer cell lines (RMG-1, MDA-MB231) and V79 cells were used. The cell killing was determined by colony forming assay, and mutation induction was determined by counting the number of 6-thioguanine resistant colonies (hprt locus mutation assay). The cell lines were irradiated with carbon (20 or 80 keV/microm) or neon beams (80 keV/microm). Carbon ions with a higher LET value (80 keV/microm) had an enhanced cytotoxic effect compared to those with a lower LET value (20 keV/microm). Carbon beams produced a slightly stronger cytotoxic effect than neon beams when irradiated at the same LET level (80 keV/microm), but the difference was not remarkable. The mutant fraction was significantly higher in all cell lines when they were irradiated with heavy ion beams, compared to the results for X-ray irradiation. The mutant fraction increased when the LET of the carbon beams increased. At equivalent LET values, the mutant fraction was lower for neon beams than for carbon beams. Fractionation of carbon beam irradiation had no effect on survival, but reduced the mutant fraction. Neon beams might be more appropriate for heavy ion therapy, especially when higher doses are being used. In addition, the fractionation of heavy ion beam administration might be appropriate for reducing the mutant fraction.

Animals↗
PubMed2001

A comparison of low versus standard dose pravastatin therapy for the prevention of cardiovascular events in the elderly: the pravastatin anti-atherosclerosis trial in the elderly (PATE).

Treatment with low drug doses is generally recommended in the elderly. However, the efficacy of low dose 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor treatment in elderly hypercholesterolemic patients has never been examined. Therefore, we compared the effect of low-dose with standard dose pravastatin, an HMG CoA reductase inhibitor, on the incidence of cardiovascular events (CVEs) in elderly patients with hypercholesterolemia in a randomized prospective trial. Subjects aged > or = 60 years (73 +/- 6 years) with serum total cholesterol (TC) levels of 220-280 mg/dL were randomized to the low-dose (groupL, 5 mg/day; n=334) or standard dose (groupS, 10-20mg/day; n= 331). Baseline TC levels were similar in the 2 groups (253 +/-15 mg/dL). Patients were followed for 3-5 years (mean 3.9 years). TC levels decreased from baseline by 11-13% in group L and by 15-17% in groupS. TC levels at 1 year in S and L group were 209 +/- 2 mg/ dL (16 +/- 1% decrease) and 221+/- 2 mg/dL (12 +/- 1% decrease), respectively. Forty two and 29 CVEs occurred in group L and S, respectively. The incidence of CVEs was significantly lower in group S than in group L (P = 0.046, generalized Wilcoxon test; P = 0.096, log-rank test). The risk ratio for group S compared with group L was 0.674 (95% confidence interval: 0.423-1.074). Subgroup analyses suggested that the difference in the incidence of CVEs between the 2 groups was more clear in subjects without diabetes mellitus, with TC levels of < 253 mg/dL, and with TG levels of > or = 133 mg/dL. The incidence of CVEs in group S was significantly lower than that in group L in subjects without both diabetes mellitus and previous cardiovascular disease (P = 0.026, generalized Wilcoxon test; P = 0.032, log rank test). These findings suggest that standard-dose pravastatin (10-20 mg/day) is more effective in reducing the incidence of CVEs in the elderly than low dose pravastatin (5 mg/ day), especially in nondiabetic elderly patients with mild hypercholesterolemia or previous cardiovascular disease.

Aged↗