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Biomedical subjects

Y Miwa

Publications and source records attributed to Y Miwa.

At least 73 records · Page 4Linked to original sources
PubMed1998

Significance of acute cerebral swelling in patients with sylvian hematoma due to ruptured middle cerebral artery aneurysm, and its management.

A retrospective study of 75 patients treated surgically for ruptured middle cerebral artery (MCA) aneurysm within 48 hours evaluated clinical grade at admission, secondary development and management of cerebral swelling associated with space-occupying hematoma, cerebral infarction caused by vasospasm, development of hydrocephalus, and clinical outcome. Clinical grade at admission was significantly better in patients without than in those with hematoma (p < 0.01). Twenty-seven patients with sylvian hematoma caused by ruptured MCA aneurysm often developed ipsilateral cerebral swelling in the early period after subarachnoid hemorrhage. Seventeen of these patients developed serious cerebral swelling and received barbiturate therapy. Nine of these 17 patients had good outcome, but six patients died of cerebral swelling. The incidence of hydrocephalus was significantly higher in patients with than in those without hematoma (p < 0.01). The incidence of infarction was more pronounced in patients with sylvian hematoma. Clinical outcome was significantly better in patients without than in those with sylvian hematoma (p < 0.01). Development of cerebral swelling in patients with sylvian hematoma due to ruptured MCA aneurysm has a significant effect on outcome, and improvements in management are required.

Adult↗
PubMed1998

[A collision tumor between squamous cell carcinoma and malignant lymphoma of urinary bladder: a case report].

A 68-year-old-male was admitted to our hospital with the chief complaint of macrohematuria. He was diagnosed with malignant lymphoma at 63 years old. Cystoscopy and computerized tomography revealed a non-papillary and broad based tumor at the anterior wall of the urinary bladder and partial cystectomy was done. Pathological diagnosis was collision tumor between squamous cell carcinoma and malignant lymphoma. To our knowledge, this is the 13th case of collision tumor associated with genitourinary organs in the literature.

Aged↗
PubMed1998

[A case report of selective IgA deficiency in rheumatoid arthritis and anti-IgA antibody induced anaphylactic transfusion].

We described a case of rheumatoid arthritis (RA) with selective IgA deficiency. A 69 year-old female with RA was admitted because of gall bladder cancer, and also had selective IgA deficiency which serum IgA level was less than 5.0 mg/dl, and IgA 1 and IgA 2 subclasses were not detected. Prior to the operation, she was given red cell compatible blood transfusion because of severe anemia. After 30 min of transfusion, she developed chill, nausea, vomiting and hypotension. These anaphylactic reactions might be induced by the presence of anti-IgA antibody, since the level of this antibody titers in her serum was elevated, assessed by the methods of ELISA and Western blotting. Although a case of RA associated with selective IgA deficiency, and also with elevated serum anti-IgA antibody level is extremely uncommon, attention should be paid to the presence of anti-IgA antibody in patients with selective IgA deficiency to avoid any unexpected anaphylactic reactions.

Aged↗
PubMed1997

The quaternary geometry of transcription termination factor rho: assignment by chemical cross-linking.

Transcription termination factor rho from Escherichia coli is a ring-shaped homohexamer of 419 amino acid subunits and catalyzes an ATP-dependent release of nascent RNA transcripts. Previous chemical cross-linking studies suggested that the rho hexamer might have D3 symmetry with three isologous dimers as protomers. However, our recent mutational analysis of rho alongside its putative structural homology to F1-ATPase rather argued for C6 symmetry. To resolve this discrepancy, we have re-investigated the pattern of cross-linking of rho using various cross-linkers with different functional groups and spacer lengths. Upon reaction with dimethyl suberimidate followed by SDS-polyacrylamide gel electrophoresis, rho protein generated a series of cross-linked oligomers up to hexamers, of which dimers migrated as distinct doublet bands of approximately equal intensities. However, the lower band became much stronger than the upper one with dimethyl adipimidate and difluorodinitrobenzene, and vice versa with disuccinimidyl glutarate, disuccinimidyl suberate and disulfosuccinimidyl tartarate. Furthermore, the trimeric products also produced doublet bands, whose relative intensities were again variable with cross-linkers, but in an inverse correlation with those of the dimer bands. These results combined with theoretical considerations support a C6 symmetry model in which cross-linking is assumed to occur stochastically at one of two alternative sites within each subunit interface with variable relative frequencies depending on cross-linkers. The D3 symmetry is excluded, for the putative trimeric subspecies should always retain mutually equal intensities in that case. Detailed inspections of the cross-linking kinetics further revealed a moderate characteristic of C3 symmetry for the rho hexamer such that the collective as well as relative rates of cross-linking at the two available sites could fluctuate between alternating interfaces. The final model designated as C3/6 is also compatible with other functional and structural properties known for rho.

Cross-Linking Reagents↗
PubMed1997

Effects of K+ channel blockers and K+ ionophore on isoprenaline-induced secretion of amylase from rat parotid acini.

The involvement of K+ channels in regulating secretion of amylase from isolated rat parotid acini was studied in conjunction with beta-adrenoceptor function. It was observed that increasing the concentration of extracellular K- or adding K+ channel blockers enhanced the secretion of amylase. Among several K+ channel blockers, tetraethylammonium, apamin and charybdotoxin were effective to enhance secretion by 48, 69 and 84%, respectively. Glibenclamide was without effect. A low concentration of isoprenaline (10(-7) M) enhanced secretion by 154% and its simultaneous application with tetraethylammonium gave a synergistic effect, producing 371% stimulation. Combination of tetraethylammonium and a low concentration of carbachol (10(-6) M) did not give the synergistic effect. Isoprenaline at the concentration of 10(-6) M enhanced secretion by 313% and this was reduced to 116% by 10(-5) M valinomycin, a K+ ionophore. Valinomycin was without effect on carbachol (10(-5) M)-induced secretion. Somatostatin (10(-5) M) and morphine (10(-4) M) also reduced isoprenaline-induced secretion of amylase. These results suggested the regulation of Ca(2+)-activated K+ channels by isoprenaline in amylase secretory processes in parotid acini.

Adrenergic beta-Agonists↗
PubMed1997

Plasma levels and hepatic mRNA expression of transforming growth factor-beta1 in patients with fulminant hepatic failure.

BACKGROUND/AIMS: Transforming growth factor-beta1 is an important cytokine involved in cell growth and inflammation which has been shown to be inhibitory to hepatic DNA synthesis. The aim of this study was to investigate the plasma levels and hepatic mRNA expression of transforming growth factor-beta1 in patients with fulminant hepatic failure in whom liver regeneration may be impaired. METHODS: Plasma levels of transforming growth factor-beta1 and human hepatocyte growth factor were measured in 57 fulminant hepatic failure patients and 20 healthy volunteers by ELISA. Northern blot analysis of transforming growth factor-beta1 and H3 histone, a marker for liver proliferation, was performed in liver tissue of 14 fulminant hepatic failure patients. RESULTS: The plasma levels of total transforming growth factor-beta1 in fulminant hepatic failure patients on admission (median 38.8 ng/ml, range 8.4-108 ng/ml) were significantly higher than those in control subjects (23.0 ng/ml, 8.5-34.9 ng/ml, p<0.001). Significantly higher levels were observed in non-A, non-B hepatitis patients (57.9 ng/ml, 38.8-108 ng/ml, n=10, p<0.001) compared to patients with paracetamol overdose (37.1 ng/ml, 8.4-72.5 ng/ml, n=47). In contrast, the plasma levels of free transforming growth factor beta1 were greater in paracetamol overdose (623 pg/ml, 46.7-1241 pg/ml, n=21) than in non-A, non-B hepatitis (131 pg/ml, 77.2-254 pg/ml, n=9), with both being higher than control (72.3 pg/ml, 28.7-108, n=7, p<0.001). The plasma levels of human hepatocyte growth factor in patients with paracetamol overdose (7.04 ng/ml, 1.00-62.4 ng/ml) were significantly higher than those in patients with non-A, non-B hepatitis (4.48 ng/ml, 0.74-9.10 ng/ml, p<0.05). Northern blots showed increased mRNA expression of transforming growth factor-beta1 in paracetamol-overdose patients (n=8, p<0.05), but not in patients with non-A non-B hepatitis (n=6), compared to controls (n=4). CONCLUSIONS: The increased circulating plasma TGF-beta1 in FHF may be part of the tissue repair process in fulminant hepatic failure. In patients with non-A, non-B hepatitis, the increased total transforming growth factor-beta1 together with a less elevated hepatocyte growth factor could be related to impaired liver regeneration in this group.

Acetaminophen↗
PubMed1997

Catabolite repression of the Bacillus subtilis gnt operon exerted by two catabolite-responsive elements.

Catabolite repression of Bacillus subtilis catabolic operons is supposed to occur via a negative regulatory mechanism involving the recognition of a cis-acting catabolite-responsive element (cre) by a complex of CcpA, which is a member of the GalR-Lacl family of bacterial regulatory proteins, and the seryl-phosphorylated form of HPr (P-ser-HPr), as verified by recent studies on catabolite repression of the gnt operon. Analysis of the gnt promoter region by deletions and point mutations revealed that in addition to the cre in the first gene (gntR) of the gnt operon (credown), this operon contains another cre located in the promoter region (creup). A translational gntR'-'lacZ fusion expressed under the control of various combinations of wild-type and mutant credown and creup was integrated into the chromosomal amyE locus, and then catabolite repression of beta-galactosidase synthesis in the resultant integrants was examined. The in vivo results implied that catabolite repression exerted by creup was probably independent of catabolite repression exerted by credown; both creup and credown catabolite repression involved CcpA. Catabolite repression exerted by creup was independent of P-ser-HPr, and catabolite repression exerted by credown was partially independent of P-ser-HPr. DNase I footprinting experiments indicated that a complex of CcpA and P-ser-HPr did not recognize creup, in contrast to its specific recognition of credown. However, CcpA complexed with glucose-6-phosphate specifically recognized creup as well as credown, but the physiological significance of this complexing is unknown.

Bacillus subtilis↗
PubMed1997

Histologic characteristics of renal cell carcinomas with lymph node metastasis.

BACKGROUND: This study was conducted to determine if there are any specific histologic features that are associated with lymph node metastasis in renal cell carcinoma (RCC). METHODS: TNM classification, histologic grade, mean nuclear volume, cell type, and histologic architecture of the tumors were evaluated in 66 patients who had undergone nephrectomy and lymphadenectomy for RCC. In the 18 patients with positive lymph node metastasis, both primary lesions and metastatic lymph nodes were evaluated. RESULTS: Lymph node status was correlated with primary tumor stage, venous involvement, and distant metastasis. The tumor grade was higher, and the mean nuclear volume was larger, in both primary and metastatic lesions of RCCs with lymph node metastasis than in tumors with no metastasis. In primary lesions of RCCs with lymph node metastasis, clear cell, alveolar, or cystic patterns were observed less frequently, and granular or spindle/pleomorphic cells and papillary or solid patterns, were observed more frequently, as compared to those lesions without metastasis. Comparison between primary and metastatic lesions in individual patients revealed no significant difference in grade or mean nuclear volume. The development of new cell types or histologic architectures, which was not noted in the primary lesions, was also a rare event in the metastatic lesions. CONCLUSION: Several characteristic histologic features, which may reflect the increased metastatic potential of the tumor, were observed in both primary and metastatic lesions in cases of RCC with lymph node metastasis. No substantial difference in histologic features was observed between the primary or metastatic lesions of individual patients.

Adolescent↗
PubMed1997

Lysophosphatidylcholine inhibits receptor-mediated Ca2+ mobilization in intact endothelial cells of rabbit aorta.

We have previously reported that lysophosphatidylcholine (LPC), which accumulates in oxidized LDL and atherosclerotic arteries, inhibits endothelium-dependent relaxation and modulates Ca2+ regulation in cultured bovine aortic endothelial cells. To test the effect of LPC on endothelium-dependent relaxation and endothelial Ca2+ regulation in intact vessels, we simultaneously measured both isometric tension and endothelial cytosolic free Ca2+ concentration ([Ca2+]i), using fura 2, in intact endothelial cells of aortic strips isolated from rabbits. In the aortic strips precontracted with phenylephrine, cumulative addition of acetylcholine (ACh) dose dependently induced endothelium-dependent relaxation, with an increase in endothelial [Ca2+]i, and positive correlation was obtained between these two parameters. LPC (2 to 20 mumol/L) inhibited both ACh (3 mumol/L)-induced endothelium-dependent relaxation and an increase in endothelial [Ca2+]i in a dose-dependent manner. On the other hand, phosphatidylcholine (20 mumol/L) affected neither ACh-induced endothelium-dependent relaxation nor an increase in endothelial [Ca2+]i. LPC had no effect on endothelium-independent relaxation and a decrease in smooth muscle [Ca2+]i induced by nitroglycerin. Thus, the inhibitory effect of LPC on endothelium-dependent relaxation is due to the inhibition of agonist-induced Ca2+ mobilization in vascular endothelial cells, which is an essential step in the synthesis of endothelium-derived relaxing factor.

Acetylcholine↗
PubMed1997

The Escherichia coli ldcC gene encodes another lysine decarboxylase, probably a constitutive enzyme.

A gene (designated ldcC) mapped at 4.6 min on the Escherichia coli chromosome codes for a protein of 713 amino acids (aa) that shows strong similarities in both size and amino-acid sequence (69% identical residues and 85% conserved residues) to lysine decarboxylase (LDC) from E. coli (CadA, acid-inducible LDC, 715 aa) or from Hafnia alvei (739 aa). A pUC18 derivative carrying the ldcC gene conferred high LDC activities on an E. coli strain devoid of the functional cadA gene, even when the bacteria were grown under non-inducing conditions at physiological pH. Thus, the gene encodes another lysine decarboxylase, probably a constitutively expressed enzyme, the presence of which was suggested from the previous observations that low LDC activities were detectable in cadA- mutant and non-induced wild-type cells.

Bacterial Proteins↗
PubMed1997

Correlation between blood parameters and symptomatic vasospasm in subarachnoid hemorrhage patients.

Serial changes in platelet and white blood cell (WBC) counts and other blood parameters were analyzed in 103 patients with aneurysmal subarachnoid hemorrhage (SAH). The WBC counts during days 3-5, 6-8, 9-11, and 12-14 after the onset of SAH were significantly higher in patients with than in patients without symptomatic vasospasm. Platelet counts during days 0-2, 3-5, 6-8, 9-11, 12-14, 15-17, 18-21, and 22-28 after SAH were significantly higher in patients with than in patients without symptomatic vasospasm. Monitoring of platelet and WBC counts may provide an indicator of the occurrence of symptomatic vasospasm.

Adult↗
PubMed1997

[Histological classification of renal cell carcinoma--problems in JUA classification].

BACKGROUND: Although renal cell carcinoma (RCC) is often heterogeneous, the histological classification of RCC in Japanese Urological Association (JUA) is designed to select only the dominant histological components. We evaluated whether this system could provide an adequate information concerning the prognosis of the patients. METHODS: Histological slides of 130 cases with RCC were microscopically evaluated. We classified these cases according to the JUA classification, and also checked the presence or absence of each histological components (3 cell types and 5 histological architectures) regardless of whether or not they were dominant. Univariate and multivariate analysis were then performed to determine the histological components which have prognostic impact on patient survival. RESULTS: Multivariate analysis demonstrated that only spinde/pleomorphic cells and solid architecture were the significant prognostic parameters. The presence of these histological components was not correctly shown in the JUA classification. CONCLUSION: The histological classification of RCC in JUA did not provide enough information about the presence of the important prognostic parameters. This system should be modified to describe all the histological components regardless of whether they are dominant or not.

Adult↗
PubMed1997

Effects of Albunex infusion on left ventricular inflow velocity in dogs.

This study examined the effects of Albunex (sonicated 5% human serum albumin) infusion on left ventricular inflow velocity by Doppler echocardiography. Left ventricular pressure and left ventricular inflow velocity were recorded simultaneously under eight different conditions in dogs: 1) baseline 1 (control), 2) Albunex 0.2 ml/kg, 3) baseline 2, 4) Albunex 0.5 ml/kg, infusion of dextran 100 ml, 5) baseline 3, 6) Albunex 0.2 ml/kg, 7) baseline 4, and 8) Albunex 0.5 ml/kg. In the normal state (no dextran), Albunex (0.2 ml/kg) caused no hemodynamic changes or inflow velocity changes. In contrast, infusion of Albunex (0.5 ml/kg) caused time velocity integrals of early filling to increase from the baseline (5.51 +/- 1.13 vs 7.19 +/- 1.14 cm, p < 0.05). After dextran infusion (100 ml), Albunex (0.2 ml/kg) caused peak early filling velocity to increase (62.4 +/- 6.9 vs 67.3 +/- 9.4 cm/sec, p < 0.05), and infusion of Albunex (0.5 ml/kg) also caused peak early filling velocity to increase from baseline (64.6 +/- 8.5 vs 73.7 +/- 14.5 cm/sec, p < 0.05). Infusion of Albunex (0.5 ml/kg) after dextran infusion caused increases in left ventricular pressure at the mitral valve opening (12.7 +/- 3.1 vs 15.2 +/- 3.3 mmHg, p < 0.05) and in left atrial driving force (13.5 +/- 3.6 vs 16.7 +/- 5.9 mmHg, p < 0.05). Clinicians should be cautious about using Albunex at doses of greater than 0.2 ml/kg when evaluating the pressure gradient of the left ventricle in patients with elevated left ventricular diastolic pressure. In patients with normal hemodynamics, Albunex infusion at doses of less than 0.2 ml/kg apparently did not affect the velocity measurement.

Albumins↗
PubMed1996

Behavioural effects of 7-OH-DPAT are solely due to stimulation of dopamine D2 receptors in the shell of the nucleus accumbens; jaw movements.

The goal of this study was to determine whether the dopamine D3 receptor in limbic structures plays a role in the shell-specific and dopamine-dependent display of jaw movements in rats. When combined with the dopamine D1 receptor agonist (+/-)-6-chloro-7,8-dihydroxy-3-allyl-1- phenyl-2,3,4,5-tetrahydro-1 H-3-benzazepine (SKF 82958, 5 micrograms), the putative dopamine D3 receptor agonist (+/-)-7-hydroxy-N, N-di-n-propyl-2-aminotetralin (7-OH-DPAT, 10 micrograms) produced repetitive jaw movements following injection into the shell, but not the core, of the nucleus accumbens. This behaviour was only partially inhibited by local blockade of dopamine D1 receptors (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1 H-3-benzazepine, SCH 23390, 500 ng), dopamine D2 receptors (domperidone, 50 and 100 ng) or dopamine D2/3 receptors (l-sulpiride, 25 ng). Combined blockade of both dopamine D1 and D2 receptors in the shell completely antagonized the jaw movements elicited by the cocktail of SKF 82958 and 7-OH-DPAT. Replacing 7-OH-DPAT by another putative dopamine D3 receptor agonist, S(+)-(4aR, 10bR)-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[I]benzopyrano[4, 3-b]-1, 4-oxazin-9-ol (PD 128,907, 10 micrograms), in the cocktail did not produce jaw movements, when administered into the shell. Injection of the cocktail of SKF 82958 and 7-OH-DPAT into the ventrolateral striatum, which contains nearly no dopamine D3 receptors, also elicited jaw movements. It is concluded that mesolimbic dopamine D3 receptors play no role in the dopamine-dependent and shell-specific jaw movements: the contribution of 7-OH-DPAT in the cocktail of SKF 82958 and 7-OH-DPAT to the display of jaw movements is solely due to its ability to activate dopamine D2 receptors.

Animals↗
PubMed1996

Protein tyrosine kinase inhibitors promote amylase secretion and inhibit ornithine decarboxylase induction in sialagogue-stimulated rat parotid explants.

Three sialagogues, isoproterenol (IPR), carbachol, and methoxamine, caused induction of ornithine decarboxylase (ODC) in cultured rat parotid explants. All the protein tyrosine kinase inhibitors tested suppressed this ODC induction but enhanced sialagogue-dependent amylase secretion. Sodium orthovanadate showed the reverse effects as the kinase inhibitors. Immunoblot analysis with anti-phosphotyrosine antibody revealed that herbimycin A depresses IPR-stimulated tyrosine phosphorylation of parotid proteins. Herbimycin A did not affect the IPR- or dibutyryl cAMP-induced surge of the parotid cAMP level but inhibited these agonist-dependent ODC inductions. These results suggest that sialagogue-induced ODC induction and amylase secretion are mediated by different signal transduction pathways and that protein tyrosine kinase participates in IPR-dependent ODC induction and amylase secretion in the process subsequent to the cAMP surge.

Amylases↗
PubMed1996

Epidural administered buprenorphine in the perioperative period.

PURPOSE: To study the effect of epidural buprenorphine on minimum alveolar concentration (MAC) of volatile anaesthetics, duration of analgesia and respiratory function in the perioperative period. METHODS: One hundred and twenty patients, ASA I-II undergoing gynaecological surgery were randomly divided into three studies. The forty patients in each study were randomly divided into four groups depending on the dosage; Group I (control), Group II (80 micrograms. kg-1 morphine), Group III (4 micrograms. kg-1 buprenorphine), Group IV (8 micrograms. kg-1 buprenorphine). The MAC of halothane was measured following epidural administration of the agents in each group. The duration of analgesia was assessed by the first request for pentazocine. Postoperative analgesic effects were assessed by the total dosage of pentazocine required for the 48 hr after surgery. Respiratory rate (RR), minute volume (MV), and PaCO2 were measured during surgery and the postoperative period. The MAC of halothane was reduced in Group IV (P < 0.01). The duration of analgesia was 10.0 +/- 5.1 hr (Mean +/- SE) in Group I, 37.7 +/- 4.7 hr in Group II, 27.1 +/- 7.1 hr in Group III, and 44.4 +/- 4.1 hr in Group IV. Total dosage of pentazocine was lower in Group IV (P < 0.05) than in the other groups. The decrease of RR, MV and the increase of PaCO2 were observed within 60 min in Group III and IV dose dependently. CONCLUSION: Epidural buprenorphine administered in a dose of 4 or 8 micrograms. kg-1 provides postoperative analgesia that is no less effective than that of morphine.

Adult↗
PubMed1996

Effect of morphine on secretion of amylase from isolated parotid acini.

The effect of morphine on amylase secretion was studied in isolated rat parotid acinar cells. It was found that aluminum fluoride (AlCl3/NaF) and dibutyryl-cyclic AMP but not by cyclic AMP, enhanced amylase secretion. Cyclic AMP was effective in enhancing secretion following permeabilization of cells with alpha-toxin. Following treatment of cells with alpha-toxin, both GTP and GTP-gamma-S also enhanced secretion. Morphine reduced AlCl3/NaF- or GTP-induced secretion of amylase, but was without effect on GTP-gamma-S-induced secretion. Photoaffinity labeling by the use of [32P] 4-azidoanilido GTP revealed its incorporation into 43 kDa and 31 kDa proteins. Incorporation was further enhanced with AlCl3/NaF. Morphine reduced labeling of the 43 kDa protein. Immunoblot analysis identified the 43 kDa GTP binding protein as Gs. When [gamma 32P] GTP was preloaded into permeabilized acinar cells and its hydrolysis measured, morphine stimulated and AlCl3/NaF inhibited GTPase activity. These results suggested the involvement of Gs in secretion of amylase. Furthermore, morphine reduced secretion of amylase by stimulating GTPase activity and by reducing the incorporation of GTP into Gs.

Affinity Labels↗