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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 451 records · Page 25Linked to original sources
PubMed1993

Primary mucinous carcinoma of the renal pelvis.

A case of primary mucinous carcinoma originating in the renal pelvis associated with renal lithiasis is reported. The left kidney removed was mostly occupied by mucinous carcinoma with areas of signet ring cell carcinoma. The epithelium covering the pelvis consisted of a single layer of columnar epithelium with scattered goblet cells and mucous glands. A series of careful examinations of the abdominal viscera failed to disclose any other primary lesion. The patient died with multiple peritoneal tumor disseminations eight months after the operation despite additional chemotherapy.

Adenocarcinoma, Mucinous↗
PubMed1993

Impairment of hippocampal long-term potentiation following transient cerebral ischaemia in rat: effects of bifemelane, a potent inhibitor of ischaemia-induced acetylcholine release.

The present study examined the changes in the long-term potentiation (LTP) of the hippocampal Schaffer collateral/CA1 pyramidal cell system in vivo occurring after 12-min forebrain ischaemia in the rat. A population spike (PS) of CA1 pyramidal cells were recorded in 18 rats at 7 h post-ischaemia. While the threshold and amplitude of pretetanic PS were not depressed, the induction of LTP was significantly impaired following ischaemic insult (155 +/- 28% of baseline PS, mean +/- SD, n = 6, p < 0.001), as compared to sham-controls (337 +/- 84%, n = 5), without reduction of single pulse responses. Pretreatment with 4(o-benzylphenoxy)-N-methylbutylamine hydrochloride (Bifemelane; 50 mg kg-1 i.p.) slightly but significantly attenuated the impairment in LTP induction (196 +/- 23%, n = 6; p < 0.02). The findings in the present study indicate that CA1 pyramidal cells are dysfunctional in synaptic plasticity long before their death. Bifemelane has been demonstrated to inhibit acetylcholine release strongly during cerebral ischaemia but not interfere with normal cholinergic synaptic transmission. The effect of bifemelane suggests that Ach release during ischaemia is partially involved in the post-ischaemic impairment of LTP induction.

Acetylcholine↗
PubMed1993

The complete amino acid sequence of subunit d of rat liver mitochondrial H(+)-ATP synthase.

Subunit d of H(+)-ATP synthase from rat liver mitochondria was isolated from the purified enzyme by reverse-phase high performance liquid chromatography. The partial amino acid sequence of the subunit was determined by automated Edman degradation of the peptide fragments. The nucleotide sequence of subunit d of rat liver H(+)-ATP synthase was determined from a recombinant cDNA clone isolated by screening a rat hepatoma cell line H4TG cDNA library with a probe DNA. The sequence was composed of 581 nucleotides including a coding region for the import precursor of subunit d and noncoding regions on the 5'- and 3'- sides. The possible precursor of subunit d and its mature polypeptide deduced from the open reading frame consisted of 161 and 160 amino acid residues with molecular weights of 18,763 and 18,631, respectively. Subunit d is a hydrophilic protein with an isoelectric point of 6.19. The sequence of the rat subunit d is highly homologous with that of subunit d of bovine heart and slightly similar to that of the subunit d of the yeast mitochondria. However, it had no homology with the sequence of any of the subunits of bacterial or chloroplast H(+)-ATP synthase.

Amino Acid Sequence↗
PubMed1993

Cytotoxic effect of hemolytic culture supernatant from Enterococcus faecalis on mouse polymorphonuclear neutrophils and macrophages.

We reconfirmed that the LD50s of hemolytic Enterococcus faecalis strains were significantly less than those of nonhemolytic E. faecalis strains in normal mice. Hemolysin produced by E. faecalis lysed human, horse, rabbit, and mouse erythrocytes, but not cow and sheep erythrocytes. Sphingomyelin comprises a part of the lipid composition of the erythrocyte membrane of all mammalian species tested. But phosphatidylcholine exists only in human, horse, rabbit, and mouse. These two lipids inhibited lysis of horse erythrocytes by hemolytic E. faecalis. Phosphatidylcholine is probably the binding component on the membrane of erythrocytes for E. faecalis hemolysin. The hemolytic culture supernatant lysed not only erythrocytes but also mouse polymorphonuclear neutrophils (PMNs) and macrophages.

Animals↗
PubMed1993

Megacystis and megacolon in an infant with Ehlers-Danlos syndrome.

We report a 14 month old male infant with Ehlers-Danlos syndrome who became 'anuric' due to an acutely dilated urinary bladder. Although the patient was also found to have megacolon, no diverticulum was seen in his gastrointestinal tract or urinary bladder. In order to decompress the urinary bladder and colonic wall, we put an indwelling urinary catheter in place for 2 months, and carried out daily glycerin enema for 3 months. All urological and gastrointestinal symptoms subsided with this intensive medical treatment. The diagnosis of megacystis and megacolon was made very early in life for this patient. This may indicate that the striking extension of gastrointestinal and bladder wall may lead to the development of diverticula of gastrointestinal and urinary tracts in later life.

Barium Sulfate↗
PubMed1993

Treatment of severe pertussis by administration of specific gamma globulin with high titers anti-toxin antibody.

Our patient presented with severe respiratory distress and marked pleocytosis. She was mechanically ventilated and received gamma globulin with high titers of anti-pertussis toxin and anti-filamentous hemagglutinin. Her clinical signs improved and a notable decrease in white blood cell count was observed. Ten months after treatment, the patient showed normal physical and mental development and anti-pertussis toxin and anti-filamentous hemagglutinin titers were significantly increased. Recently, the effectiveness of gamma globulin therapy has been emphasized again. Our experience supports the use of iv gamma globulin infusion. Also, gamma globulin did not influence the patient's own immunologic response to pertussis. Gamma globulin therapy with high anti-pertussis toxin titers could be considered for treatment of severe pertussis.

Antitoxins↗
PubMed1993

The transport mechanism of an organic cation, disopyramide, by brush-border membranes. Comparison between renal cortex and small intestine of the rat.

The characteristics of disopyramide uptake in brush-border membrane vesicles isolated from rat renal cortex and small intestine were investigated. Transport of disopyramide into an osmotically reactive intravesicular space was observed with notable binding to the membrane surface. An outwardly directed H+ gradient stimulated disopyramide uptake, resulting in a transient uphill transport in both brush-border membranes. As for the renal brush-border membrane, the H+ gradient itself appeared to be the driving force for this stimulation of uptake. These findings suggest that disopyramide-H+ antiport is the mechanism of disopyramide action in renal cell membrane. The initial uptake was saturable (Km and Vmax of 68.0 microM and 1.25 nmol (mg protein)-1/30 s, respectively). The stimulation of disopyramide uptake by an outward H+ gradient in rat intestinal brush-border membrane was due to an interior negative H(+)-diffusion potential. A K(+)-diffusion potential (interior negative) enhanced disopyramide uptake. These results suggest that there are different mechanisms of disopyramide uptake for renal and intestinal brush-border membrane vesicles.

Animals↗
PubMed1993

[In vivo effect of growth-inhibitor produced by Pseudomonas aeruginosa isolates and anti-pseudomonal drugs on model infection due to Pseudomonas aeruginosa].

Pseudomonas aeruginosa Nos. 1 and 5, each co-existing growth-inhibitor-producing and -nonproducing cells, were used in this study. An equal number of both cells (each 10(8) CFU/mouse) was challenged intraperitoneally to mice, and these cells in the heart blood and kidneys of mice were determined. Furthermore, the effect of piperacillin, ceftazidime and sisomicin on the cell distribution in mice was studied in the model infection due to P. aeruginosa Nos. 1 and 5. As a control experiment both cells of P. aeruginosa No. 1 were each challenged intraperitoneally at a dose of 10(8) CFU/mouse to mice of two groups, but there were no marked differences between the two types in cell counts of the heart blood or kidneys 9 hours after challenge. When a concomitant challenge of both cells (each 10(8) CFU/mouse) was performed in mice, the number of growth-inhibitor-producing cells of the heart blood and kidneys was about 100 times greater than that of the non-producing cells. These in vivo results were well comparable to the previous in vitro results and indicated that the inhibitor affected the invasion of the non-producing bacteria in the body in the model infection due to P. aeruginosa isolates consisting of the two types of cells. Similar results were obtained in mice with the model infection due to P. aeruginosa No. 5. Anti-pseudomonal drugs such as piperacillin (50 mg/mouse) and ceftazidime (50 mg/mouse) and sisomicin (1 mg/mouse) were given intramuscularly to mice infected concomitantly with both cells of P. aeruginosa No. 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[An adult patient with EDTA-dependent pseudothrombocytopenia due to rubella virus infection].

We experienced an adult patient with EDTA-dependent pseudothrombocytopenia due to rubella virus infection. A 23-year-old male complaining of eruption and fever was admitted to our hospital on June 21, 1992. Laboratory findings on admission showed the platelet count 1.5 x 10(4)/microliters with EDTA, but 11.5 x 10(4)/microliters with heparin. Platelet agglutination was absorbed in the peripheral blood smear samples with EDTA. The hemagglutination inhibition titer for rubella virus raised from 1:32 to 1:52 in paired sera. We diagnosed this patient as having EDTA-dependent pseudothrombocytopenia and mild true thrombocytopenia due to rubella virus infection.

Adult↗
PubMed1993

In vitro and in vivo antibacterial activities of E1077, a novel parenteral cephalosporin.

E1077, a new injectable cephalosporin with a broad antibacterial spectrum and potent antibacterial activity, was evaluated for its in vitro and in vivo antibacterial activities in comparison with those of cefpirome, cefuzonam, ceftazidime, and cefotaxime. E1077 showed broad in vitro antibacterial activity against gram-positive and gram-negative bacteria. Against methicillin-susceptible Staphylococcus aureus, E1077 was as active as cefpirome; the MIC for 90% of strains tested (MIC90) was 1.0 microgram/ml. Against methicillin-resistant S. aureus, E1077 was less active (MIC90, 64 micrograms/ml). For Enterobacter cloacae and Pseudomonas aeruginosa, E1077 was fourfold more active than cefpirome, with MIC90s of 1.0 and 16 micrograms/ml, respectively. For Proteus vulgaris, the MIC90 of E1077 was 32 micrograms/ml, which was fourfold greater than that of cefpirome. Against other gram-negative strains tested, the in vitro activity of E1077 was comparable to that of cefpirome. The broad antibacterial spectrum of E1077 was reflected by its in vivo efficacy against experimental septicemia caused by gram-positive and gram-negative bacteria. Against S. aureus 90 and P. aeruginosa E7, E1077 had activity superior to those of the reference compounds; against most other bacterial strains, the efficacy of E1077 was similar to that of cefpirome. Levels of E1077 in plasma and tissue of mice were studied. At 15 min after a single subcutaneous administration, E1077 displayed high peak levels (mean, 31.8 +/- 3.1 micrograms/ml). These results indicate that the in vitro and in vivo efficacies of E1077 are similar to those of cefpirome except against P. aeruginosa and P. vulgaris.

Animals↗
PubMed1993

Changes in regional myocardial function and external work in exercising dogs with ischemia.

Changes in regional myocardial work of the nonischemic wall and left ventricular (LV) asynchrony of the nonischemic wall during exercise-induced ischemia were examined in seven conscious dogs instrumented with a micromanometer for LV pressure measurement and sonomicrometers for control and ischemic wall thickness and LV external short and long axes. Ischemia was produced during steady-state exercise by a pneumatic constrictor on the left circumflex coronary artery. Time difference between peak thickening of control (anterior) and ischemic (posterior) walls was measured as an index of LV asynchrony. LV pressure-wall thickness loop area of both the control wall (LVP-CW loop) and ischemic wall was calculated as an index of regional myocardial external work. With ischemia during exercise, peak LV pressure decreased by 11%, and time difference of peak thickening in the two walls increased, accompanied by marked deformation of the LVP-CW loop during early relaxation, which was related to protodiastolic thickening of the ischemic wall. Thus, despite a significant increase in percent systolic thickening during exercise, loop area of control wall was not enhanced. These changes of the LVP-CW loop were confirmed by calculation of stress-strain loop areas as an additional index of regional myocardial external work but having true dimensions of work. Stress-strain loop area in the control wall during ischemic exercise showed a similar value to that during control exercise, thereby confirming lack of compensatory increase. Thus, during exercise-induced ischemia, regional myocardial external work in the normal region does not increase despite an increase in systolic wall thickening.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Impaired early and intact late diastolic function in stunned myocardium induced by demand ischemia.

Changes in left ventricular diastolic properties of pacing-induced stunned myocardium were examined in 10 anesthetized dogs instrumented with a micromanometer for left ventricular pressure and sonomicrometers for left ventricular short axis, anterior and posterior segment lengths, and posterior wall thickness. After the creation of a critical stenosis on a carotid-circumflex coronary artery bypass, left ventricular pressure and dimensions were recorded simultaneously during temporary superior and inferior vena caval occlusion to allow for the construction of end-diastolic pressure-segment length curves. After 15 min of high-frequency pacing (190-220 beats/min), measurements were repeated and compared with those before pacing. The mean lengthening rate of each dimension during the first half of diastole was calculated as an index of early diastolic function. Three minutes after the end of pacing, coronary blood flow and perfusion pressure were unchanged, whereas systolic function of the posterior wall was depressed, indicating stunning of the posterior myocardium. The time constant of left ventricular pressure decay was prolonged by 14%. The mean lengthening rate during the first half of diastole decreased by 50% in the left ventricular internal short axis and by 119% in the posterior segment. Despite the significant impairment of early diastolic function, the regional end-diastolic pressure-segment length relation of the posterior wall was unchanged. Thus, in contrast to the results reported for pacing-induced ischemia that were measured immediately after pacing, the distensibility of the left ventricular wall in stunned myocardium induced by pacing was unchanged despite depressed early diastolic function.

Animals↗
PubMed1993

Increased afterload intensifies asynchronous wall motion and impairs ventricular relaxation.

To clarify whether impaired left ventricular relaxation elicited by increased afterload is attributable to regional dyssynchrony, we analyzed in dogs simultaneous left ventricular contrast ventriculography and pressure before and during angiotensin II infusion. Regional shortening was measured by a centerline method and a video-intensity method that served to define asynchronous motion. During angiotensin II, peak left ventricular pressure increased 35 +/- 6 mmHg, and the isovolumic pressure time constant (tau) was prolonged from 32.7 +/- 4.1 to 39.2 +/- 7.6 ms (P < 0.01). During increased afterload, early diastolic asynchrony, confined to the apical (5 of 7) and inferior regions (2 of 7), was detected in all dogs. Early systolic asynchrony was detected in the apical (5 of 7) and inferior (1 of 7) regions in six dogs. At control, systolic excursion was lower in the anteroapical than in the anterobasal region (P < 0.05). During angiotensin II, excursion of all regions was reduced, with the apical region lower than other regions (P < 0.01). In the normal dog heart, impaired relaxation with augmented afterload is coincident with asynchronous wall motion, especially in the apical-inferior region. Temporal dispersion of regional contraction may explain delayed left ventricular relaxation associated with increased afterload.

Angiotensin II↗
PubMed1993

Determining the site of airway collapse in obstructive sleep apnea with airway pressure monitoring.

Twenty patients with obstructive sleep apnea (OSA) underwent complete polysomnography and simultaneous upper airway pressure monitoring with a custom-made, soft silicone-covered catheter measuring 2.3 mm in diameter. The catheter had four solid-state microtip pressure sensors positioned in the posterior nasopharynx, immediately caudal to the tip of the uvula, at the level of the hyoid bone, and in the midesophagus. The level(s) of airway collapse was determined by changes in the pressure patterns between transducers. In 14 of the 20 patients, airway collapse was confined or initiated at the oropharyngeal region. The obstruction extended to the base of tongue in 7 and to the entire collapsible upper airway in 2 patients. Four patients had collapse at the base of the tongue and 2 had collapse at the hypopharynx. The site of airway collapse remained fairly constant through various sleep stages and positions. Uvulopalatopharyngoplasty (UPPP) and postoperative polysomnography were performed in 4 patients (2 with hypopharyngeal, 1 with base of tongue, and 1 with oropharyngeal airway collapse). Two patients had a favorable response to UPPP.

Female↗
PubMed1993

Turbidimetric-kinetic assay of endotoxin in rumen fluid or serum of cattle fed rations containing various levels of rolled barley.

A new, automated turbidimetric-kinetic (ATK) assay was used to quantitate bacterial endotoxin in rumen fluid or in serum of Holstein steers. The ATK method used Limulus amebocyte lysate (LAL) reagent with added beta-glucan (LAL-ES) which improved specific sensitivity to endotoxin. Design of the feeding trial permitted comparison of endotoxin levels found during consumption of a basal ration with those higher levels detected at various times following the introduction of increasing percentages of rolled barley to that basal ration. Both serum and ruminal endotoxin levels were significantly higher in steers on the higher concentrate rations. Peak endotoxin levels were detected 20 days following the change to the highest concentrate ration which contained 60% barley. Endotoxin levels from both sources subsequently decreased. Ruminal endotoxin stabilized at about 10 times the level, and serum endotoxin stabilized at 2 to 4 times the level, of that previously found during feeding of the basal ration. Test protocol included sample dilution and heating in order to avoid the effects of endotoxin inhibitors. Recovery rates for added endotoxin to either serum or rumen fluid supernates ranged from 120 to 136%. Coefficient of variation for endotoxin concentration in serum was lower than 10%, and in rumen fluid only slightly higher. There was significant correlation between ruminal concentration as measured by the ATK method and an alternative chromogenic substrate assay procedure. Changes in endotoxin level in experimental steers were those predictable from experience with naturally occurring incidents of grain engorgement. The ATK assay appears to be an accurate and rather simple technique which will prove useful for experimental and clinical studies in the future.

Animal Feed↗
PubMed1993

Low plasma 19-hydroxyandrostenedione levels in patients with aldosterone-producing adenoma.

The present study was performed to clarify changes in plasma levels of 19-hydroxyandrostenedione (19-OH-AD), an amplifier of aldosterone and a possible hypertensinogenic steroid, during several tests for the renin-angiotensin system in 20 patients with aldosterone-producing adenoma (APA) and to determine whether 19-OH-AD participates in the etiology of the hypertension in this disorder. Basal plasma 19-OH-AD levels in patients with APA were significantly lower than those in 50 normal subjects, and correlated positively with basal plasma cortisol levels (r = 0.45, P < 0.05). Plasma 19-OH-AD levels were not changed significantly by 2-h standing during which plasma renin activity (PRA) remained suppressed. With 40 mg iv furosemide plus 2-h standing during which PRA remained suppressed, plasma 19-OH-AD levels increased significantly with a concomitant significant increase in plasma cortisol. With dexamethasone pretreatment, however, such positive responses of plasma 19-OH-AD and cortisol disappeared. After the removal of the APA with the adjacent adrenal tissue, PRA and plasma aldosterone concentrations became normal or low-normal, but plasma 19-OH-AD and cortisol did not change as compared with the preoperative levels. There were no significant correlations between basal plasma 19-OH-AD levels and mean blood pressure either before or after the adrenal operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗