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Biomedical subjects

S Oda

Publications and source records attributed to S Oda.

At least 325 records · Page 18Linked to original sources
PubMed1991

Comparative aspects of microsomal cytochrome P-450-dependent monooxygenase activities in musk shrew (Suncus murinus), Mongolian gerbil (Meriones unguiculatus), harvest mouse (Micromys minutus) and rat.

1. The cytochrome P-450 content (0.75 +/- 0.13 nmol/mg microsomal protein) in musk shrew (suncus, Suncus murinus) liver microsomes was lower than that (1.30 +/- 0.26) in rat liver microsomes, but it is approximately the same level as in the Mongolian gerbil (Meriones unguiculatus, 1.18 +/- 0.14), harvest mouse (Micromys minutus, 1.11 +/- 0.02) and rat. 2. The hydroxylation activity (based on cytochrome P-450) of medium-chain fatty acids (otanoic, decanoic, lauric and tridecanoic acids) is much higher in suncus, Mongolian gerbil and harvest mouse than in rat, with the exception of the activity of decanoic and tridecanoic acids in Mongolian gerbil. 3. This suggests that cytochrome P-450 species catalyzing the hydroxylation of medium-chain fatty acids are present in these laboratory animals in higher concentrations. 4. The aminopyrine N-demethylation activity based on microsomal protein or cytochrome P-450 in suncus is significantly lower than that in rat, but the N-demethylation activity in Mongolian gerbil and harvest mouse is approximately 1.7-2.0-fold greater than that in rat.

Aminopyrine↗
PubMed1991

Developmental analysis of the eye lens obsolescence (Elo) gene in the mouse: cell proliferation and Elo gene expression in the aggregation chimera.

This study investigates the primary effect of the eye lens obsolescence (Elo) gene of the mouse. Morphological features of the Elo lens were defined as follows: (1) deficient elongation of lens fiber cells, (2) morphological abnormality of nuclei of lens fiber cells, (3) lack of eosinophilic granules in the central fiber cells and (4) rupture of lens capsule in the posterior region. We have immunohistologically examined, by means of an in vivo BrdU incorporation system, whether or not the Elo gene regulates cell proliferation during lens development. The lens fiber cells were morphologically abnormal in day 13 embryonic Elo lens. However, there were no significant differences in morphology or cell proliferation between normal and Elo lens epithelium until day 14 of gestation. After day 15, the total cell number in the Elo lens epithelium was significantly less than that in the normal, but the total numbers of S-phase cells in the two genotypes were not significantly different. The ratio of the total S-phase cell number to the total number of lens epithelial cells may be affected by the developmental stage, but not directly by the genotype. The genotype, however, may be having a direct influence at later ages because malformation of Elo lens fiber cells must cause reduction of the total number of lens epithelial cells in older embryos. Although, at 30 days old, Elo lens cells were externally extruded through the ruptured capsule into the vitreous cavity, BrdU-labelled lens epithelial cells were detectable. To investigate whether the Elo lens phenotype is determined by its own genotype or by its cellular environment, we produced aggregation chimeras between C3H-Elo/+(C/C) and BALB/c(c/c). Most lenses of BALB/c dominant chimeras were oval in shape without the ruptured lens capsule. However, they were opaque in the center and slightly smaller in size than normal. The lenses of C3H-Elo/+ dominant chimeras were morphologically similar to the Elo lens. Although normal nuclei were regularly arranged in the anterior region, Elo-type nuclei were located in the posterior region. Immunohistological staining by using anti-C3H strain-specific antibody demonstrated that the lens fiber cells with abnormal nuclei were derived only from C3H-Elo/+, not from BALB/c. These observations suggest that the primary effect of the Elo gene in the developing lens may be specific to the fiber cell differentiation rather than to the cell proliferation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Fine structure of the atrial cardiocytes in the house musk shrew (Suncus murinus).

The atrial and ventricular cardiocytes of the house musk shrew were examined by immunohistochemistry, and the right atrium containing the auricle was studied by transmission electron microscopy. The atrial natriuretic peptide (ANP)-granules of the cardiocytes in the auricle and the rest of the atrium were also analyzed by ultrastructural morphometry. On immunohistochemistry, ANP immunoreactivity was detected in the atria, with the most intensely reacting cardiocytes being localized in the right auricular part of the atrium. ANP immunoreactivity was not detected in the ventricular muscles. On ultrastructure, in most of the atrial cardiocytes including the auricle, ANP-granules, well-developed Golgi apparatus and rough endoplasmic reticulum were observed, and the nuclei were characteristically situated in the periphery of the cardiocytes, being different from many other mammalian hearts. The ANP-granules were classified into two types (A and B), with most of these granules being located in the paranuclear region in association with the Golgi apparatus, and a few ANP granules being observed throughout the sarcoplasmic layers intervening between the myofibrilar bundles. On ultrastructural morphometry, the total number of granules in the right auricular cardiocytes was significantly greater than those in the atrial cardiocytes, and the diameter of the A-granules was significantly greater than that of the B-granules in both the atrial and auricular cardiocytes.

Animals↗
PubMed1991

Alpha 2-adrenergic modulation of glucagon and insulin secretions in sheep.

To investigate the effects of alpha 2-adrenergic receptors on the secretions of pancreatic glucagon and insulin, clonidine, midaglizole and yohimbine were intravenously administered in four conscious sheep. Clonidine infusion at a dosage of 1.0 nmol/kg/min produced hyperglucagonemia, hypoinsulinemia and hyperglycemia. Midaglizole or yohimbine was infused for 30 min, at doses of 5, 10 and 50 nmol/kg/min during the clonidine infusion. The highest yohimbine infusion (50 nmol/kg/min) blocked the clonidine-induced responses of glucagon, insulin and glucose. On the other hand, the midaglizole (50 nmol/kg/min) infusion brought about no statistical effect on the clonidine-induced responses of glucagon, insulin and glucose. The alpha 2-adrenergic antagonistic effect of midaglizole was clearly less than that of yohimbine in the present experiments. It is concluded that the glucagon secretion is enhanced and the insulin release is inhibited by alpha 2-adrenergic stimulation in conscious sheep.

Adrenergic alpha-Antagonists↗
PubMed1991

[Myocardial infarction beginning with cerebral symptoms in 30 cases of cardio-cerebral apoplexy].

A clinicopathological analysis of myocardial infarction with an onset of stroke-like symptoms was carried out on 30 autopsy cases at the Tokyo Metropolitan Geriatric Hospital. The cases were classified into four groups according to the types of brain lesions, I: embolism (n = 17), II: thrombosis (n = 9), III: bleeding (n = 2), and IV: no remarkable focal lesion (n = 2). Classification was made based on clinical findings, and pathological features. The characteristic clinical findings were conciousness disturbance, no elevation of blood pressure at the onset of stroke, hemiplegia and shock. However, the typical anginal chest pain was found in only 17% of cases. The underlying diseases and complications were hypertension, atrial fibrillation (Af), disseminated intravascular coagulation (DIC), renal failure, malignant neoplasma, and diabetes mellitus. The incidences of Af, DIC, mural thrombus, non-bacterial thrombotic endocarditis (NBTE) were significantly higher in the group with cerebral embolism than in the group with cerebral thrombosis. The coronary stenotic index was also smaller in the group with cerebral embolism. Therefore, the major etiology of cardio-cerebral apoplexy was a simultaneous embolism to the brain and heart due to Af, NBTE or, DIC.

Aged↗
PubMed1991

Functional imaging of cerebral blood volume using simultaneous measurements of dynamic and xenon computerized tomography (CT).

This report describes a method for measuring regional cerebral blood volume (r-CBV), by simultaneously using dynamic computerized tomography (DCT) and stable Xenon-enhanced CT (Xe CT). Local cerebral blood flow (CBF) was measured using a Xe CT blood sampling method, and mean transit time (MTT) was calculated using DCT after a rapid injection of iodinated contrast material. A functional image of r-CBV was obtained from multiplication of CBF and MTT on each pixel using the formula: CBF x MTT = CBV. This calculated value is not suitable to indicate a r-CBV which directly reflects cerebral microcirculation. Accordingly, only a comparative estimation of relative r-CBV images is applicable. However, laterality of image and comparison of serial studies are useful in hemodynamic evaluations, especially in ischemic cerebrovascular diseases, because they indicate hemodynamic reserve within the hypoperfused region.

Adult↗
PubMed1991

[Combined antibacterial activity of aztreonam and clindamycin against clinically isolated strains].

It has been reported in some studies that the combination of aztreonam (AZT) and clindamycin (CLDM) have high clinical effectiveness in the treatment of intractable infections. We, therefore, studied combined in vitro antibacterial activity of these 2 compounds using many freshly isolated strains. 1. AZT and CLDM in combination had synergistic effects on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Haemophilus influenzae, which are sensitive or quasi-sensitive to CLDM, in the presence of CLDM at MIC or sub-MIC. 2. For Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa, which are not sensitive to CLDM, the 2 drugs in combination showed synergistic effects on some species and additive or slightly additive effects on most species in the presence of CLDM at those concentrations which are usually maintained in blood. 3. The 2 drugs showed no antagonism.

Aztreonam↗
PubMed1991

[Hemopurification in the management of ARDS complicating multiple organ failure].

In the field of critical care medicine, it has been claimed that ARDS often develops as a part of multiple organ failure (MOF). Since multi-modality therapy is necessary in the management of MOF, it is also mandatory even in the management of ARDS. Among the various therapeutic approaches for patients with MOF, hemopurification is one of the most effective therapeutic tools. Various hemopurification methods such as hemodialysis, peritoneal dialysis, hemoadsorption, hemofiltration and plasma exchange have been applied in the management of MOR. However, our recent experiences suggest that continuous hemofiltration (CHF) and/or continuous hemodiafiltration (CHDF) are safest, most easily performed and effective hemopurification in the management of ARDS/MOF. The efficacy of hemopurification in the management of ARDS is summarized as follows. 1) Removal of humoral mediators and causative substances of ARDS following insults such as sepsis and trauma. 2) Treatment of pulmonary interstitial permeability edema which has been claimed to be one of the most important pathological conditions in ARDS. 3) Removal of excess water given as carrier in IVH solution and accumulating in the body. 4) Immunomodulation which has also been considered to be necessary in the treatment or prevention of ARDS.

Hemofiltration↗
PubMed1991

[Bacteriological study on fosfomycin against organisms clinically isolated from paranasal sinusitis].

Multi-center bacteriological and clinical studies on fosfomycin (FOM) nasal solution were performed in subjects with paranasal sinusitis from January, 1988 to May, 1990. In these studies, we were exclusively responsible for bacterial isolation from clinical sources, bacterial identification and the determination of drug susceptibility. Before local administration of FOM nasal solution, many strains of various bacterial species were isolated from sources totalling 396 cases involved in phase II clinical studies, dose-finding and open clinical studies. From antibacterial activities of FOM against those isolates, we obtained the following conclusions. 1. Among the 447 isolates, Streptococcus spp. occupied 25.7%, Staphylococcus spp. 21.7% and anaerobic Gram-positive cocci (GPC) 13.6%, showing high detection frequency of aerobic and anaerobic GPC. Next to these, Haemophilus influenzae, Pseudomonas aeruginosa, Klebsiella spp. and Branhamella catarrhalis also were often obtained. 2. After exclusion of possibly contaminating strains which might have entered into cultures at samplings or transfers, the MIC50 and the MIC80 of FOM against the remaining 354 isolates were determined to be 12.5 and 25 micrograms/ml, respectively, indicating that local use of FOM would be fully effective to eradicate most of the bacteria. 3. FOM nasal solution showed sufficient eradication efficacy against most clinical isolates of possible causative organisms of paranasal sinusitis, and appeared to be useful as a topical preparation for the treatment of this disease.

Administration, Intranasal↗
PubMed1991

[Antimicrobial activity of cefpiramide to fresh clinical isolates].

In the subjects of 835 strains of 37 clinically isolated microbial strains, which were separated and identified among materials collected from patients with various infections and which were sent from medical therapeutic institutions throughout Japan in 1990, for the purpose of examining the antimicrobial activity of cefpiramide (CPM), its minimum inhibitory concentration (MIC), together with those of other cephem antibiotics, was determined, and the following conclusions were obtained. 1. Microbial strains in which no CPM-resistant strains emerged were Streptococcus pyogenes, Streptococcus pneumoniae and Anaerobic Gram-positive cocci. 2. In comparison with reports by many researchers at the former half of the 1980s, microbial stains suggesting an increase in resistance to CPM were Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas cepacia, Pseudomonas putida, Acinetobacter calcoaceticus, and Haemophilus influenzae, but also in other microbial strains the resistance to CPM was observed in high ratios. 3. Among strains used in the test, methicillin-resistant S. aureus, cephamycin and oxime type cephalosporin-resistant Gram-negative bacilli of Enterobacteriaceae, and new quinolone-resistant microbes were observed in high ratios; therefore, it was considered that CPM could not exert sufficient antimicrobial activities to these strains because of many resistant strains being complicated among these "CPM-resistant strains". 4. It was discussed that "the resistance mechanism observed throughout beta-lactam drugs as a while and the study themes in the dimension including social circumstances where resistant strains emerged", as pointed out by the authors in 1989, increased the significance of these days in the evaluation of timecourse changes in microbes resistant to specific drugs including CPM. 5. There are many unfavorable conditions in the antimicrobial activities of CPM to clinically isolated strains in recent years. However, it was jointly confirmed that CPM maintained effective antimicrobial activities to the majority of clinically isolated strains. Furthermore, when it was additionally considered that CPM was one of not many cephem drugs having persistent blood levels, a conclusion was drawn that CPM was one of clincally useful cephem drugs even at present.

Anti-Bacterial Agents↗
PubMed1991

[Remarkable improvement of anemia by administration of recombinant human erythropoietin in a patient with aplastic anemia].

A 69-year-old female was admitted for pancytopenia. The hematological examination showed leukocytes 1,800/microliters, hemoglobin 5.3 g/dl and platelets 9.6 x 10(4)/microliters. A bone marrow aspiration revealed hypoplasia, but no abnormal cells. Serum erythropoietin titer was 5,100 mU/ml. Diagnosis of aplastic anemia was made. She received 400 ml of blood transfusion twice, and was then treated with recombinant human erythropoietin (rHuEPO) (12,000 U/day) three times a week for eight weeks. Hemoglobin level gradually increased to the level of 12.0 g/dl. This case suggests that there are some cases of aplastic anemia which can respond to treatment with rHuEPO.

Aged↗
PubMed1991

[Antibacterial activities of ofloxacin against recent isolates from patients with community-acquired infections].

In order to survey antibacterial activities of ofloxacin (OFLX) against 1,440 bacterial strains isolated from patients with community-acquired infections in 1987 and 1990, minimum inhibitory concentrations (MICs) of the drug as well as those of other new quinolones and oral cephems were determined. The following conclusions were reached. 1. Comparison of the MIC distribution for strains isolated in 1987 with those in 1990 suggested a tendency toward an increase in the frequency of OFLX-resistant isolates with the passage of time of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Citrobacter spp., Klebsiella ssp., Enterobacter spp., Proteus vulgaris, Morganella morganii, Providencia spp., and Acinetobacter calcoaceticus. Most common elevations of MIC values against these bacteria were observed in MIC80 and MIC90 values, while no significant alteration was observed in MIC50 values. However, MIC50's of OFLX against Serratia marcescens and Pseudomonas aeruginosa were relatively high for strains isolated in both 1987 and 1990. Most of the OFLX-resistant strains of S. aureus seemed to be methicillin-resistant (MRSA). Furthermore, MIC80 of OFLX against coagulase-negative staphylococci was high in strains isolated in both 1987 and 1990. 2. Susceptibility of Streptococcus spp. was evaluated only in strains isolated in 1990. The results were comparable to those reported by others in the early 1980s. 3. Bacteria which showed no or infrequent emergence of OFLX-resistant strains even in 1990 were Proteus mirabilis, Haemophilus influenzae, Neisseria gonorrhoeae, Campylobacter spp. and Peptostreptococcus spp. 4. Recently isolated strains from patients with community-acquired infections showed a tendency toward an increase of the frequency of OFLX-resistant strains among many bacteria. However, the bacteria which contained high percentages of OFLX-resistant strains except for MRSA were so-called less-virulent bacteria, and in the other bacteria elevations of MIC values were only observed in MIC80 and MIC90. These results suggested that OFLX preserved a potent antibacterial activity against bacteria which were major causative pathogens in community-acquired infections.

Bacteria↗
PubMed1991

[Optimal hypervolemic therapy for symptomatic vasospasm].

Thirty-five patients with symptomatic vasospasm (SV) following aneurysmal subarachnoid hemorrhage (SAH) were managed according to a method based on hemodynamic manipulation, monitored by Swan-Ganz catheter. Nine out of these had delayed surgery. For those who developed SV, the pulmonary wedge pressure (Pcwp) and/or central venous pressure (CVP) were immediately increased up to the point at which neurological deficit was reversed by rapid injection of fresh frozen plasma, albuminates, low molecular dextrose, and glycerol. On this regimen, patients were closely observed for any neurological change. Then the hemodynamic parameters were maintained as optimal values until they could be reduced below optimal values without reappearance of neurological deficit. In inoperable patients, special attention was given in making a decision about discontinuing the regimen. The results were compared with thirty-seven patients with SV who were treated with conventional hypervolemic therapy (CHT) by continuous administration of albuminates. In the treatment of CHT, optimal values could hardly be established, so the same hemodynamic parameters were applied in all the cases. From this study, in the majority of the cases optimal values were found as follows: Pcwp up to 10-15 mmHg, and CVP below 11 cmH2O. On the contrary, in 20% of patients, neurological deficit was reversed by increasing CVP to a point not above 7 cmH2O. Correlation between neurological reversal and systemic blood pressure was not statistically significant. After this regimen (OHT), 74% of patients showed immediate improvement after volume expansion, and, in 80%, outcome was good, while 20% died. The motor function at the time of discharge was more than 3 on the manual test in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Central Venous Pressure↗