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Biomedical subjects

K Miyazaki

Publications and source records attributed to K Miyazaki.

At least 559 records · Page 31Linked to original sources
PubMed1990

[Studies on gallium alloys for dental restorations. 2. Electron probe microanalysis for hardened gallium alloys].

Hardened gallium alloys were analyzed by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The cores, matrix and white irregular shape phases were visible with SEM. The round or irregular shape cores contained Ag, Pd, Cu and Zn but did not contain Ga and In. The dark irregular shape matrix, which surrounded the core, consisted of Ga-Ag, Ga-Pd, Ga-Cu and Ga-Sn phases. However, the amount of Ga-Sn phase was very low. The white phase in the matrix was Ag-In phase.

Dental Alloys↗
PubMed1990

[Ectopic prostatic polyp preoperatively diagnosed as bladder tumor: a case report].

We report a case of ectopic prostatic polyp preoperatively diagnosed as bladder tumor. Several examinations highly suggested the possibility of a bladder tumor invading prostatic tissue, but the exophytic lesion was located proximal to the verumontanum. Transurethral resection of the lesion was performed, and the histological examination revealed typical findings of benign prostatic hyperplasia. We reviewed 42 cases of ectopic prostatic tissue reported in the Japanese literature. Ectopic prostatic tissue should be considered in the differential diagnosis of hematuria in the male.

Choristoma↗
PubMed1990

[Experience in the use of propiverine hydrochloride (P-4) for patients suffering from urinary frequency and/or incontinence].

The clinical effectiveness and safety of propiverine hydrochloride (P-4, 20 mg tablet) were studied on 29 patients with nervous pollakisuria, neurogenic bladder or unstable bladder, whose chief complaints were urinary frequency and/or urinary incontinence. The clinical efficacy was "good" or better in 62.1% and "fair" or better in 86.2%. Patients' impressions were "good" or better in 79.3%. There were a total of 4 cases (13.8%) of adverse reactions, namely, two cases of decreased urinary stream, one dry mouth, and one dizziness. These reactions disappeared rapidly after the completion or discontinuance of drug administration, and therefore, did not constitute significant safety problems. The clinical efficacy in the treatment of subjective symptoms was 74.1% for diurnal pollakisuria, 50.0% for nocturnal pollakisuria, 83.3% for urinary incontinence and 69.0% for urgent feeling of micturition. For objective symptoms, P-4 increased significantly the volume of maximum desire to void (MDV); however it did not increase significantly the residual urine volume. The results of this study suggest that propiverine hydrochloride is very useful for the treatment of urinary frequency and/or incontinence.

Adult↗
PubMed1989

Elevation of sialyl stage-specific mouse embryonic antigen levels in pleural effusion in patients with adenocarcinoma of the lung.

Sialyl stage-specific mouse embryonic antigen (SSEA-1) levels were measured in pleural effusions obtained from patients with lung cancer and benign pulmonary disease, using a solid-phase immunoradiometric sandwich assay. The mean (+/- SEM) levels (unit/ml) of pleural fluid sialyl SSEA-1 were 3620 +/- 1419 in adenocarcinoma (n = 25), 123 +/- 30 in nonadenocarcinoma (n = 13) and 95 +/- 19 in benign pulmonary disease (n = 13), respectively. The positive rate was 64% in adenocarcinoma, 7.7% in nonadenocarcinoma, and 0% in benign pulmonary disease, respectively, when a cutoff level was defined as the mean + 3 SD value (300 unit/ml) based on pleural fluid sialyl SSEA-1 levels in benign pulmonary disease. There was a significant positive correlation between pleural fluid levels of sialyl SSEA-1 and those of carcinoembryonic antigen in adenocarcinoma patients (r = 0.8246, P less than 0.01). Pleural fluid sialyl SSEA-1 levels correlated with cytologic findings in adenocarcinoma patients. These observations suggest that sialyl SSEA-1 in pleural effusion is a useful marker to discriminate malignant from nonmalignant and adenocarcinoma from nonadenocarcinoma of the lung.

Adenocarcinoma↗
PubMed1989

Stimulation of DNA synthesis in hepatocytes by Kupffer cells after partial hepatectomy.

The role of Kupffer cells during reparative regeneration of rat liver was investigated with an in vitro experimental model. Conditioned media from primary cultures of Kupffer cells isolated from intact and regenerating liver were added to primary cultures of hepatocytes, and [3H]thymidine incorporation into DNA was studied. Kupffer cell-conditioned media from intact liver and regenerating remnant liver significantly stimulated DNA synthesis in hepatocytes as compared with control media (p less than 0.05). Moreover, the stimulating activity of Kupffer cells prepared from regenerating liver at 6 and 12 hr after partial hepatectomy was significantly higher than that of Kupffer cells from untreated rats (p less than 0.05). The activity was found in serum-free conditioned media. This stimulating activity exponentially increased as the increase of the number of the cultured cells, indicating that the stimulating activity was released directly by cultured Kupffer cells. These results suggest that Kupffer cells stimulate DNA synthesis in hepatocytes by producing and releasing certain factor(s) at an early stage of liver regeneration after partial hepatectomy.

Animals↗
PubMed1989

Involvement of pancreatic polypeptide (PP) in luminal feedback regulation in the conscious rat.

The possibility of the involvement of pancreatic polypeptide (PP) release in luminal feedback regulation in the conscious rat was examined. Pancreatic secretion in the intestinal phase in the rat is regulated by negative feedback control so that a decrease in luminal protease activities produced by a diversion of bile-pancreatic juice (BPJ) from the intestine stimulates pancreatic secretion. Plasma concentration of rat PP and the effect of exogenous infusion of rat PP on pancreatic secretions during BPJ diversion were determined. Plasma PP concentration significantly increased with BPJ diversion and peaked at 90 min after BPJ diversion began, almost paralleling changes in protein output. Exogenous PP infusion (1, 2 and 10 micrograms/kg/hr) inhibited pancreatic protein and fluid outputs but not the bicarbonate output during BPJ diversion. PP was shown to be physiologically released in the intestinal phase of pancreatic secretion; however, the physiological role of endogenous PP remains unknown.

Animals↗
PubMed1989

Effects of synthetic human gastrin-releasing peptide on pancreatic exocrine secretion and release of pancreatic polypeptide in conscious rats.

The effects of a newly synthesized peptide, human gastrin-releasing peptide (hGRP), on the pancreatic exocrine secretion and the release of pancreatic polypeptide (PP) were examined in the conscious rat. Plasma PP concentrations were determined by a recently established specific radioimmunoassay for rat PP. Amounts of 0.18, 0.35, and 3.5 nmol/kg/h hGRP significantly stimulated both pancreatic exocrine secretion and 0.35 nmol/kg/h of hGRP increased PP release. Simultaneously infused proglumide (300 mg/kg/h) did not affect either pancreatic exocrine secretion or PP release. However, simultaneous infusion of atropine (100 micrograms/kg/h) slightly inhibited PP release, but did not restrict the incremental response of pancreatic protein secretion to hGRP. These results suggest that hGRP directly stimulates pancreatic exocrine secretion and PP release.

Animals↗
PubMed1989

Effect of secretin and caerulein on pancreatic polypeptide and on insulin secretion from the isolated perfused ventral area of the rat pancreas.

The secretion of pancreatic polypeptide (PP) and insulin (IRI), stimulated by secretin or caerulein was investigated in the isolated perfused ventral area of the rat pancreas. The effect of atropine on these secretory responses was examined. Secretin (100-1000 pM) stimulated transient PP secretion and this response was completely inhibited by 10 microM of atropine. However, 10 pM secretin and 10-1000 pM caerulein did not stimulate the secretion of PP. Caerulein transiently stimulated IRI secretion and this response was not inhibited by atropine, but 10-1000 pM secretin did not stimulate IRI secretion. Therefore, the supraphysiological dose of secretin stimulates PP secretion probably via an intrapancreatic release of acetylcholine, while caerulein stimulates IRI secretion by a direct action.

Animals↗
PubMed1989

Posterior extensive simultaneous multisegment decompression with posterolateral fusion for cervical myelopathy with cervical instability and kyphotic and/or S-shaped deformities.

From June 1978 to May 1988, posterior decompression with posterolateral fusion was performed at Tenri Hospital on 63 cases of cervical myelopathy with instability and/or malalignment including kyphotic and/or S-shaped deformities. Among 46 cases followed up for more than 1 year, 41 cases (89.1%) improved; 21 cases (45.7%) were rated excellent, six (13%), good; 14 (30.4%), fair; one (2.2%), unchanged; and four (8.7%), poor. On x-ray examination, bone consolidation at the bone implanted area was satisfactory in 30 cases (65.2%). Cervical instability disappeared at 55 cervical interspaces of 40 cases (78.6%). Displacement at unstable interspace disappeared or improved at 49 of 61 cervical interspaces (80.3%). Although cervical kyphosis or S-shaped deformity could not be improved, accelerated progression of these deformities appeared to be prevented.

Adult↗
PubMed1989

Transport characteristics of [3H]-chlorpromazine across rat small intestinal brush border membrane.

The transport mechanism of chlorpromazine, a tertiary amine, has been investigated using brush border membrane vesicles isolated from rat small intestine. Chlorpromazine was taken up rapidly by the vesicles the uptake being mainly due to binding to the membrane. The transport of chlorpromazine into the intravesicular space was facilitated by the transmembrane electrical potential difference (inside negative) induced by valinomycin or sodium thiocyanate. This facilitating effect was observed only when the transmembrane electrical potential difference was induced after chlorpromazine uptake had reached a steady state. In the initial phase of chlorpromazine uptake, there was no effect. Therefore, it is suggested that both rapid binding to brush border membrane and transmembrane electrical potential difference (inside negative) across the membrane plays a significant role in the transport processes of chlorpromazine through the intestinal epithelium.

Animals↗
PubMed1989

Involvement of sialic acid in high-affinity binding of quaternary ammonium compounds by brush border membrane from rat intestine.

As one approach to clarify the absorption mechanisms of quaternary ammonium compounds (QACs), their binding characteristics have been studied using brush border membrane vesicles isolated from rat small intestine and liposomes composed of phospholipid and GM3 ganglioside. The binding of propantheline was significantly decreased when the vesicles were pretreated with neuraminidase. Propantheline and methochlorpromazine bound to the liposomes, the binding for the latter drug being significantly greater than that for propantheline. When GM3, isolated from rat small intestine, was incorporated into the liposomes their binding capacity for both drugs increased significantly. It is suggested that the binding of QACs to the lipid layer and sialic acid play a role in the high binding of drugs to the intestinal brush border membrane. Furthermore, a sensitive and reproducible high-performance liquid chromatographic method for sialic acid has been developed.

Animals↗
PubMed1989

Comparison of transport characteristics of amino beta-lactam antibiotics and dipeptides across rat intestinal brush border membrane.

The transport characteristics of amino beta-lactam antibiotics, ampicillin and cephradine, have been examined and compared with that of glycylglycine using brush border membrane vesicles isolated from rat small intestine. The initial rate of glycylglycine uptake was markedly stimulated in the presence of an inward H+ gradient compared with the uptake rates in the absence of an H+ gradient. With the same H+ gradient the stimulation of cephradine uptake was lower and ampicillin uptake was not altered. Cephradine uptake, however, was greater than that of glycylglycine in both vesicular conditions ((pH)i greater than (pH)o and (pH)i = (pH)o). Inhibitory effects of dipeptides, ampicillin and cephradine on the initial uptake of glycylglycine were also examined. Glycylglycine uptake was significantly decreased in the presence of L-phenylalanylglycine or carnosine. Ampicillin and cephradine did not alter the uptake of glycylglycine. These results suggest that the contribution of the inward H+ gradient to the permeation of ampicillin, cephradine and glycylglycine across the rat small intestinal brush border membranes is different for each of the substances examined.

Alanine↗
PubMed1989

Release of pancreatic polypeptide and its mechanism in luminal feedback regulation in the conscious rat.

Exclusion of bile and pancreatic juice (BPJ) from the proximal intestine increases the release of pancreatic polypeptide (PP) from 4.4 to 14.3 pM and its increase was diminished by the intravenous infusion of atropine (100 micrograms/kg/h) in conscious rats. Neither intravenous bolus injection nor continuous infusion of cerulein did increase plasma PP concentration. It is suggested that the increase in plasma PP concentration produced by BPJ diversion is regulated by cholinergic mechanism, but not by cholecystokinin (CCK) released despite the known fact that BPJ diversion increases plasma CCK concentration.

Animals↗
PubMed1989

A case of multiple endocrine neoplasia (MEN) type 1; the immunohistochemical and ultrastructural studies of its tumors and the analysis of hormones in tumor extracts.

We reported a case of sporadic multiple endocrine neoplasia type 1, with multiple insulinoma, parathyroid adenoma, and pituitary tumor. Measurement of hormone contents and immunohistochemical studies of the pancreatic tumors showed that the tumors contained insulin, glucagon, somatostatin, and pancreatic polypeptide. Furthermore, the concentrations of these hormones were different in each tumor. Insulin extracted from the pancreatic tumors analyzed by reversed-phase high performance liquid chromatography revealed no structural abnormalities. On the other hand, in gel filtration evaluation of the extract of the parathyroid adenoma, it was found that the tumor extract contained a macromolecular parathyroid hormone (molecular weight 20,000 to 25,000).

Adenoma↗
PubMed1989

Vasoactive intestinal polypeptide stimulates cholecystokinin secretion in perfused rat duodenum.

We examined the effect of vasoactive intestinal polypeptide (VIP) on cholecystokinin (CCK) secretion from the isolated perfused rat duodenum. VIP stimulated CCK secretion mono-phasically in a concentration-dependent manner in concentrations ranging from 10(-9) to 10(-7) M, and 10(-7) M of VIP led to an increment of 82 +/- 25.8 fmole/3 min. The stimulatory effect of VIP on CCK was not inhibited by 10(-5) M atropine. These results suggest that VIP may directly stimulate CCK secretion from the duodenum and work as a non-cholinergic, peptidergic neurotransmitter.

Animals↗
PubMed1989

Enhanced accumulation of hyaluronate in the culture of skin fibroblasts from two patients with Coffin-Lowry syndrome.

Cultured skin fibroblasts were prepared from two unrelated adult patients with full expressions of Coffin-Lowry syndrome. Glycosaminoglycans (GAGs) were isolated either from the medium or from the cell layer of cultured skin fibroblasts. Two-dimensional electrophoresis of GAG preparations on cellulose acetate film revealed that hyaluronate was the major component both in the medium and in the cell layer. Quantitative analysis of GAGs was carried out by measuring optical density at 615 nm of Alcian blue-stained GAG spots on electrophoretograms. Increase in the hyaluronate content was found both in the culture medium and in the cell layer of Coffin-Lowry fibroblasts. In addition, the incorporation of [14C]glucosamine into hyaluronate was similarly activated in skin fibroblasts from patients, suggesting the active biosynthesis and or the suppressed degradation of hyaluronate by cultured skin fibroblasts from Coffin-Lowry syndrome. The abnormal metabolism of hyaluronate in Coffin-Lowry fibroblasts may be implicated in some of the clinical aspects of this genetic disorder.

Abnormalities, Multiple↗
PubMed1989

[Relationship among the composition and the physical and chemical properties of photo-cured composites for crown and bridge].

In this study, the relationship among the chemical composition and the physical and chemical properties of four photo-cured composites and one heat curing composite for crown and bridge were investigated. Five composites were composed of the base monomer, UDMA, TriEGDMA, 1, 3-BDMA, 1, 4-BDMA, 1, 10-DDMA, 1, 12-DDDMA or those mixture, and the composite-filler consist of the resin (TMPTMA, UDMA, 1, 10-DDMA or 1, 12-DDDMA) and micro-silica particles. Four photo-curing composites had a high elastic modulus and Vickers hardness and a low thermal expansion coefficient and water sorption compared with the heat-cured composite (Is). The effects of filler contents in the composites examined were positively on the elastic modulus and the hardness, and were inversely on the bending strength and the thermal expansion coefficient of the cured products. While the organic phase in the composite fillers had effect on the abrasive resistance of the composites. But no significant correlation between the abrasive resistance and the filler contents and the physical properties of the materials tested was noted.

Composite Resins↗