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Biomedical subjects

M Miyazaki

Publications and source records attributed to M Miyazaki.

At least 469 records · Page 26Linked to original sources
PubMed1995

Increased serum type IV collagen 7-S levels in patients with hepatic metastasis.

OBJECTIVE: The purpose of this study was to assess serum type IV collagen 7-S domain (IV 7-S) levels in colorectal cancer patients with hepatic metastasis and to investigate the relation between serum IV 7-S levels and type IV collagenase activities in tumor tissue. METHODS: Tissue type IV collagenase activity and serum IV 7-S were measured in 50 colorectal cancer patients without hepatic metastasis and in 26 patients with hepatic metastasis. RESULTS: Type IV collagenase showed significantly higher activities in colorectal cancer (n = 36) than in colorectal normal mucosa (n = 36) (p < 0.001), but significantly lower activities were shown in the hepatic metastatic tumor (n = 18) than in the primary tumor (n = 36) and normal liver tissue (n = 18) (p < 0.001). No significant correlation was found between type IV collagenase activities in the tumor and serum IV 7-S levels. Colorectal cancer patients with hepatic metastasis (n = 26) had significantly higher serum IV 7-S levels than those without hepatic metastasis (n = 50) (p < 0.001). Moreover, serum IV 7-S levels correlated significantly with hepatic metastatic tumor volume in patients with synchronous (r = 0.719, p < 0.001, n = 26) and in patients with metachronous (r = 0.910, p < 0.001, n = 16) hepatic metastasis. CONCLUSION: We suggest that serum IV 7-S levels may increase in hepatic metastasis, not by the degradation of type IV collagen in the primary and secondary tumors, but by the enhanced production of type IV collagen responsive to hepatic metastasis. The measurement of serum IV 7-S levels might be a useful tumor marker of hepatic metastasis reflecting hepatic metastatic tumor volume.

Adult↗
PubMed1995

Influence of light intensity on shear bond strength to dentin.

PURPOSE: To investigate the influence of light intensity on dentin bond strength of five dentin bonding systems. MATERIAL AND METHODS: The light intensity used to polymerize specimens was controlled at the levels of 100, 200, 400, 600, 800, and 1000 W/m2 (470 +/- 40 nm). Labial surfaces of freshly extracted lower bovine incisors were ground with #600 grit SiC paper to expose dentin. After primer application, bonding agents were applied and bonded with resin composites. A shear bond strength test was performed and the data were analyzed by a one-way ANOVA followed by Newman-Keuls multiple comparison (P<0.05). RESULTS: Statistical analysis of the data indicated that light intensity affected the bond strength to dentin. The mean bond strength of all bonding systems decreased with lower light intensity. The tendency of decreasing bond strength was different among the test materials and each test material had a threshold light intensity that resulted in statistically the same bond strength obtained using a light intensity of 1000 W/m2.

Analysis of Variance↗
PubMed1995

[Word fluency in spinocerebellar degeneration].

Two types of verbal fluency task-initial letter fluency and category (semantic) fluency--were examined in eleven patients with spinocerebellar degeneration (SCD), twenty four patients with Parkinson disease (PD), and twenty control subjects without neurological signs and symptoms. All patients and subjects showed normal results from the screening test for dementia. The numbers of initial letter fluency were less than those of category fluency in all groups. For category fluency, patients with SCD or PD had significantly lower scores than controls. For initial letter fluency, patients with SCD produced significantly lower scores than controls, but patients with PD did not produce significantly lower scores than controls. It is considered that the poor performance on both initial letter and category fluency in patients with SCD or Pd was related to disturbance of semantic memory associated with subcortical impairment, and the poor performance on initial letter fluency in patients with SCD was caused by the initiation and retrieval problems based on disturbance of frontostriatal circuits and linguistic systems. Therefore, we suggested cerebellar hemisphere played a role on the order and timing of rule-based generation of letters.

Adult↗
PubMed1995

MR of childhood-onset dentatorubral-pallidoluysian atrophy.

MR findings in a 14-year-old boy with progressive myoclonic epilepsy, who was diagnosed as having dentatorubral-pallidoluysian atrophy by DNA analysis, were compared with those of his father, who had adult-onset dentatorubral-pallidoluysian atrophy. Besides showing severe brain atrophy, especially of the brain stem tegmentum and cerebellum, MR showed diffuse periventricular hyperintensity on T2-weighted images. As compared with the proband, the father had a mild case.

Adolescent↗
PubMed1994

Identification as beta-adducin of a protein interacting with rabphilin-3A in the presence of Ca2+ and phosphatidylserine.

Rabphilin-3A is a putative target protein for Rab3A small GTP-binding protein implicated in neurotransmitter release. We have previously identified a Rabphilin-3A-interacting protein with a Mr of about 115 kDa in bovine brain. We have attempted here to purify this protein and to determine its primary structure. Amino acid sequence analysis has revealed that this protein is a bovine counterpart of human beta-adducin which is known to be a good substrate for protein kinase C. The Rabphilin-3A-interacting protein also binds to protein kinase C in the presence of Ca2+ and phosphatidylserine. These results indicate that Rabphilin-3A binds to beta-adducin in the presence of Ca2+ and phosphatidylserine.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Activation of hydrogen peroxide by copper (II) complexes with some histidine-containing peptides and their SOD-like activities.

The reactivities of copper(II) complexes with histidine-containing oligopeptides towards active oxygen species such as hydrogen peroxide (H2O2) and superoxide ion (O2-) were investigated by electron spin resonance (ESR)-spin trapping and thiobarbituric acid (TBA) methods. At physiological pH values, Cu(II) complexes with oligopeptides containing histidyl residue at the N-terminal could more easily activate H2O2 to yield hydroxyl radical (.OH) than other Cu(II)-oligopeptide complexes containing histidyl residue in the second or third position. Further, it was suggested that since all Cu(II)-oligopeptide complexes examined could scavenge O2-, these complexes have SOD-like activities.

Amino Acid Sequence↗
PubMed1994

Invasive growth patterns of hepatic hilar ductal carcinoma. A histologic analysis of 18 surgical cases.

BACKGROUND: Postoperative recurrence of hepatic hilar ductal carcinoma usually occurs in a localized region around the surgical margin, such as the bile duct. This study was aimed at assessing the invasive patterns of the hepatic hilar ductal carcinoma by histologically examining surgical specimens obtained by extended liver resection, especially the involvement of intrahepatic duct. METHODS: Eighteen resected specimens of hepatic hilar ductal carcinoma were histologically investigated. Multiple sections vertical to the extrahepatic and intrahepatic bile duct were made at a 5-mm interval. The extension of carcinoma was evaluated on each of three layers (mucosal, extramucosal-intramural, and extramural), and routes of the invasion were examined. RESULTS: Extramucosal extent toward the hepatic side was observed in 14 patients (77.8%) and that toward the duodenal side in 8 patients (44.4%) (P < 0.05). The distance of extramucosal tumor extent was also significantly longer (P < 0.05) in the hepatic side than in the duodenal side. Histologic tumor margin was usually identified in the extramural layer. Two patients had discontinuous extramucosal invasion. The lymphatic invasions were observed most frequently, followed by perineural invasion, and venous invasion was rare. In the extramucosal invasion of the liver, the left dominant carcinomas had extended toward the left, whereas those right dominant had extended toward the right (P < 0.05). Well differentiated differentiated tubular adenocarcinomas extended to the liver more extensively than moderately and poorly differentiated ones, but not significantly. CONCLUSIONS: The authors examined the extramucosal invasion of hepatic hilar ductal carcinoma. This invasion extended more frequently and further to the hepatic side than to the duodenal side, usually by the route of the extramural layer.

Adenocarcinoma↗
PubMed1994

A novel saturation transfer contrast method for 3D time-of-flight magnetic resonance angiography: a slice-selective off-resonance sinc pulse (SORS) technique.

Saturation transfer contrast (STC) techniques have been employed to decrease the signal intensity of observed water by saturating a broad proton component. The STC pulse, generally spatially nonselective, reduces the signal of brain background tissues as well as inflowing blood in 3D time-of-flight (TOF) angiography. We present a novel technique, a slice-selective off-resonance sinc pulse (SORS), which is employed to enhance inflowing blood and to suppress the signal of stationary background tissues. The STC effects of the SORS and other spatially nonselective methods influencing inflowing blood is discussed in detail. Angiograms using the SORS method are also presented to demonstrate improved vessel conspicuity. In addition, the SORS method is applicable to imagers with a whole-body RF transmitter system.

Brain↗
PubMed1994

Elongation factor 1 alpha is a component of the subcortical actin bundles of characean algae.

Antibodies to elongation factor 1 alpha (EF1 alpha), a known 50 kDa actin-bundling protein in Dictyostelium, identified a protein in a whole cell extract of the characean alga Nitella pseudoflabellata that had an apparent molecular weight of 51 kDa. Indirect immunofluorescence microscopy revealed labelling by the EF1 alpha antibodies of the subcortical actin bundles, even after the motile organelles of the endoplasm were removed by perfusion with ATP-containing solutions.

Actins↗
PubMed1994

Increase in production of hepatocyte growth factor by human embryonic lung fibroblasts in the process of aging in culture.

It was determined whether human hepatocyte growth factor (hHGF)-producing ability would change in the human embryonic lung fibroblast cell strains (MRC-5 and IMR-90) until the cells senesced in culture. The effects of phorbol 12-myristate 13-acetate (PMA), dexamethasone, and transforming growth factor-beta 1 (TGF-beta 1) on hHGF production were also studied in these cell strains. For stimulation of DNA synthesis of adult rat hepatocytes in primary culture, hHGF secreted by MRC-5 cells at 39.9 and 69.8 population doubling levels (PDLs) showed almost the same activity as recombinant hHGF. Secretion of hHGF by MRC-5 cells increased about threefold between 37.3 and 67.8 PDLs. IMR-90 cells also showed about a threefold increase in hHGF secretion with increased passage from 37.8 to 66.0 PDL. Both cell strains showed almost the same ratio of hHGF amount in the cell extracts to that secreted into the medium around 40 and 70 PDLs. Northern blot analysis showed that the transcriptional level of the hHGF gene in MRC-5 cells increased about three-fold from 42.0 to 73.6 PDL in culture. These findings indicated that hHGF production increased in both cell strains with aging in culture. Production of hHGF in both cell strains was remarkably stimulated by treatment with 10 nM PMA. On the other hand, hHGF production in both cell strains was slightly suppressed by treatment with 1 microM dexamethasone. TGF-beta at a concentration of 5 ng/ml prominently inhibited hHGF production in both cell strains. The response of both cell strains to these regulators for hHGF production was almost the same around 40 and 70 PDLs in culture.

Animals↗
PubMed1994

Spectral analysis of electromyogram in lumbar muscles: fatigue induced endurance contraction.

In the last few years, epidemiological studies have shown correlations between the low endurance capacity of the erector spinae muscle and low back pain (LBP). In this study, the function of the erector spinae muscle and localized muscle fatigue in LBP were investigated in both LBP patients and control subjects without LBP, using surface multi-channel electromyograms (EMG). Four positions (L1, L2, L4, L5) were chosen as representative locations for the different functions of the erector spinae muscle. Median frequency (fm) parameters of an EMG power density spectrum were monitored to quantify localized muscle fatigue. This research indicated a statistically significant difference (P < 0.05) in fm parameters between the LBP patients and the control subjects. The integrated electromyogram (iEMG) signals of LBP patients were considerably higher than for the control subjects during endurance isometric contraction. Our research suggested that human fatiguing erector spinae muscle, in submaximal voluntary contractions tests, induced a different firing order of motor unit spikes between two groups.

Adult↗
PubMed1994

Infantile spasms with predominantly unilateral cerebral abnormalities.

To investigate the pathogenesis of infantile spasms, 12 children underwent a combination of neurophysiologic and neuroimaging studies including brainstem evoked potentials and single photon emission computed tomography with 99mTcHMPAO. Three of the children had localized cerebral abnormalities on neuroimaging, i.e. right frontotemporal cortical microdysgenesis, left frontotemporal polymicrogyria, and right parietooccipitotemporal porencephalic cyst. Neurophysiologic studies also indicated that a single cerebral hemisphere was predominantly involved, while the other hemisphere and the brainstem were relatively spared, a result compatible with the clinical findings of hemiparesis and hemiconvulsion. In these three patients, administration of carbamazepine was followed by marked improvement of the clinical and electroencephalographic findings. Our results suggest that a combination of noninvasive examinations can distinguish a particular subtype of infantile spasms associated with a localized cerebral abnormality and responsive to carbamazepine.

Carbamazepine↗
PubMed1994

Antihypertensive, antiatherosclerotic, and plasma lipid-lowering effects of monatepil, a novel calcium antagonist with alpha 1-adrenoceptor-blocking activity in experimental animals.

Traditional antihypertensive therapy has been shown to reduce the incidence of hypertension-related vascular injuries; however, it is not fully effective against cardiovascular abnormalities. In some animal models, calcium antagonists have been demonstrated to possess antiatherogenic properties but to have no effects on plasma lipid levels, whereas alpha 1-adrenoceptor blockers have been shown to reduce plasma lipid levels. Monatepil is a new type of calcium antagonist that also has alpha 1-adrenoceptor-blocking activity. Therefore, it is thought that monatepil may have both antiatherosclerotic and plasma lipid-lowering effects in addition to its slow-onset and long-lasting antihypertensive effect. To determine the antiatherosclerotic effects of monatepil, we examined its effect on experimental atherosclerosis induced by feeding a high-cholesterol diet to monkeys, whose lipid metabolism resembles that of humans. Monatepil, at a daily dose of 30 mg/kg, at which plasma levels are equivalent to those in clinical antihypertensive therapy, was administered orally for 6 months. Monatepil suppressed elevation of cholesterol in the aorta and reduced the atherogenic (sudanophilic) area. Histologic examination revealed that monatepil-treated monkeys exhibited little aggregation of foam cells in either the aorta or coronary arteries compared with vehicle-treated atherogenic monkeys. In addition, monatepil showed preventive effects against increases in total cholesterol and low density lipoprotein (LDL), and against decreases in high density lipoprotein in plasma caused by cholesterol loading. The plasma lipid-lowering effect may be mediated through up-regulation of the number of hepatic LDL receptors by the alpha 1-adrenoceptor-blocking activity, and the antiatherosclerotic effect may be produced by the combined calcium antagonist, alpha 1-adrenoceptor-blocking, and antilipid peroxidation activities. In summary, monatepil is an antihypertensive agent belonging to a new class with antiatherogenic properties and the ability to reduce plasma lipid levels.

Adrenergic alpha-Antagonists↗
PubMed1994

Up-regulation of hepatic LDL receptor gene expression by monatepil, a novel calcium antagonist, in high cholesterol diet-fed Japanese monkeys.

The action of the novel antihypertensive calcium antagonist monatepil on the hepatic LDL receptor was investigated at the gene expression level to clarify the mechanism of its hypolipidemic effect. In cholesterol-fed control monkeys, the LDL receptor mRNA level decreased to approximately 30% of that in the normal diet-fed monkeys. However, the administration of monatepil increased LDL receptor mRNA to normal levels (three- to fourfold stimulation). It is suggested that monatepil raises the number of LDL receptors in liver tissue and that this increase may accelerate the removal of plasma LDL. Treatment with prazosin, an alpha 1-adrenoceptor antagonist, also increased the LDL receptor mRNA level, but this restorative effect was much weaker than that of monatepil, suggesting that mechanisms additional to its alpha 1-adrenoceptor blocking activity are involved in the hypolipidemic effect of monatepil.

Animals↗
PubMed1994

Localization and quantitation of active renin in monkey kidney by radioinhibitor binding and in vitro autoradiography.

We developed an in vitro autoradiographic method to localize and quantify active renin in primate tissues. Active renin in monkey kidney sections was labeled with the primate specific renin inhibitor, 3H-CGP29287, and quantitated with autoradiography and computerized densitometry. Microscopic emulsion autoradiography was carried out to clarify the detailed localization of the binding. Non-specific binding to aspartyl proteases other than renin was blocked using 1 mumol/L of N-acetyl-pepstatin. To assess the usefulness of this procedure, binding of 3H-CGP29287 was examined both by film and emulsion autoradiography in the kidneys of monkeys (Macaca fuscata) that were given chronically either an angiotensin converting enzyme inhibitor (trandolapril), an angiotensin II receptor antagonist (E4177), or vehicle. 3H-CGP29287 was found to bind very selectively to the juxtaglomerular apparatus (JGA) under control conditions. In monkeys treated with trandolapril or E4177, 3H-CGP29287 binding was increased in proportion to the increase in renal renin concentration determined enzymatically; in these kidneys, emulsion autoradiography revealed radioinhibitor binding extending far from the JGA. The potency of a series of unlabeled renin inhibitor in competing for 3H-CGP29287 binding in the autoradiographic system closely paralleled their potencies, as determined in inhibiting renin by an enzymatic assay. This technique permits specific labeling of the catalytic site of renin in the monkey kidney sections.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

Generator mechanism of pain-related evoked potentials following CO2 laser stimulation of the hand: scalp topography and effect of predictive warning signal.

In order to clarify the generator mechanism of pain-related evoked potentials (pain EPs), we studied the scalp topography of the pain EPs following CO2 laser stimulation of hand dorsum by using balanced sternovertebral electrodes as the noncephalic reference in 11 normal volunteers. We also examined the effects of predictive warning signal (light-emitting diode) on the pain EPs. In both the warned and unwarned conditions, all of the 22 hand stimulations showed a large negative component (N2) at the peak latency of about 213 ms followed by a large positive component (P2) at the peak latency of about 329 ms. A preceding small negative component (N1) at the peak latency of about 148 ms was detected in 12 of the 22 hand stimulations in the warned condition and in 13 of the 22 hand stimulations in the unwarned condition. P2 was significantly larger and occurred earlier in the warned condition than in the unwarned condition, whereas other components did not differ between the two conditions, suggesting that an increased attention of the subject to the stimulus influenced the generator mechanism of the P2 component. With regards to the scalp topography, N2 was maximal at Cz and widespread transversely to both sides, whereas P2 was maximal at Cz or Pz and spread more posteriorly than N2. These findings suggest that P2 is generated by a different mechanism from N2 and is most likely associated with pain-related cognitive function. N1 was localized to the contralateral central and midtemporal areas, confirming that the nociceptive inputs are perceived in the sensory cortex in humans. The question as to whether the N1 component is generated in the hand area of the primary somatosensory cortex or in the secondary somatosensory cortex, or in both areas, remains to be solved.

Adult↗
PubMed1994

Effect of transscleral Nd:YAG laser cyclophotocoagulation: research for a new manner of treatment.

Twenty-six eyes of 24 patients with advanced glaucoma refractory to conventional therapy were treated with noncontact neodymium: YAG laser cyclophotocoagulation and were followed for a minimum of 6 months postoperatively. The mean baseline intraocular pressure (IOP) was 34.2 +/- 2.0 mm Hg. Nine to 10 evenly spaced pulses per quadrant were circumferentially applied 2.0-2.5 mm posterior to the limbus. Eight to 35 pulses (mean, 19 pulses) were delivered per treatment with an energy per pulse of 3.9-5.7 J (mean, 4.7 J), and the total energy per treatment was 35.6-164.9 J (mean 91.1 J). Twelve eyes of 11 patients (46%) required 2 or more treatments (mean, 1.7). The mean final IOP was 17.0 +/- 2.1 mm Hg, and the mean percent decrease in IOP was 41.7 +/- 6.5%. Statistical analyses revealed that the IOP reached its lowest point about 1 week after treatment and remained that level through 6 months of follow-up. There were significant correlations between the percent pressure decrease and preoperative IOP, the number of administered pulses and the total energy at the last procedure. Based on these results, we introduce intentional multiple treatments as a new manner of treatment to avoid phthisis bulbi. An initial treatment is performed circumferentially for 180 degrees and if sufficient pressure reduction is not obtained, an additional treatment 180 degrees should be employed 1 week after the most recent procedure, whether initial or not.

Adult↗