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Biomedical subjects

S Onodera

Publications and source records attributed to S Onodera.

At least 235 records · Page 13Linked to original sources
PubMed1986

Width and lattice spacing in radially compressed frog skinned muscle fibres at various pH values, magnesium ion concentrations and ionic strengths.

The width (D) and the 1,0 lattice spacing (d1,0) at various ionic compositions of mechanically skinned single fibres (from semitendinosus muscle of Rana catesbeiana) were measured at various concentrations of polyvinyl pyrrolidone (PVP K-30, Mn = 40 000) from 0 to 6% at 20 degrees C. In a standard relaxing solution (4 mM MgATP2-, 1 mM Mg2+, 4 mM EGTA, ionic strength 150 mM and pH 7), d1,0 decreased exponentially as the PVP concentration increased: d1,0 was 41.3 +/- 0.4 (mean +/- S.D.) nm at 0% PVP and 32.9 +/- 0.4 nm at 6% PVP. D was proportional to d1,0 except at very low PVP concentrations, i.e. at 1% PVP, D decreased by 7%, whereas d1,0 decreased by only 3%. At 0% PVP, D and d1,0 decreased when either pH or ionic strength (gamma/2) was lowered. At 6% PVP, D and d1,0 decreased with lowered pH or increased [Mg2+], but was independent of gamma/2. The radial stiffness, or degree of resistance to the changes of D against the compressing force, increased considerably at d1,0 less than or equal to 35 nm in a standard relaxing solution, but not at pH 5.5 or 30 mM [Mg2+]. These effects of pH, [Mg2+] and gamma/2 on D or d1,0 and on the radial stiffness can be explained by the modification of the properties of the elastic element and the hinge between subfragment-1 and -2 and/or the hinge between subfragment-2 and light meromyosin.

Animals↗
PubMed1986

Biological activity and electron microscopy of poliovirus 14S particles obtained from alkali-dissociated procapsids.

Highly purified 14S subunit particles were obtained from alkali-dissociated poliovirus type 1 procapsids (naturally occurring empty capsids in poliovirus-infected cells) to compare their morphological and biophysical properties with those of naturally occurring 14S particles. Procapsid-derived 14S particles (PC-14S), like naturally occurring 14S particles, were capable of self-assembly into an empty shell in buffer or extracts from uninfected cells. These empty capsids always exhibited pIs more acidic than those of procapsids but were themselves distinguishable by their respective pIs. Nevertheless, if PC-14S or naturally occurring 14S particles were incubated with extracts made from poliovirus-infected cells, procapsidlike empty shells were formed. This clearly showed that the 14S particle, however obtained, possesses the information to form an empty shell of correct dimensions but of improper conformation, unless a factor present in poliovirus-infected cells is present. With the electron microscope, the PC-14S subunit frequently was seen as a pentagonal structure with a diameter of 20.4 +/- 1.4 nm, a size somewhat larger than expected for a subunit composing 1/12th of the poliovirus surface. Upon self-assembly in vitro, the empty shell formed exhibited a diameter of 29 +/- 1 nm and a wall thickness of ca. 6 to 7 nm. It was necessary to avoid CsCl banding of procapsids in their preparation as this treatment altered both their pI and their sensitivity to alkali dissociation into 14S subunits. The relevance of these findings to the nature and role of procapsids and the requirement for a morphopoietic factor in poliovirus morphogenesis is discussed.

Capsid↗
PubMed1986

Functional and metabolic responses to ischemia in the perfused heart isolated from normotensive and spontaneously hypertensive rats.

The difference between normotensive rats (WKY) and spontaneously hypertensive rats (SHR) in functional and metabolic responses to ischemia was studied. Systolic arterial blood pressure of SHR (171.2 +/- 2.9 mmHg) was significantly higher than that of WKY (135.3 +/- 1.2 mmHg), and the left ventricular mass of SHR was larger than that of WKY. Hearts isolated from either WKY or SHR were perfused by the working heart technique. Ischemia was induced by lowering the afterload pressure of the working heart. Ischemia produced cardiac arrest, and decreased the tissue levels of adenosine triphosphate and creatine phosphate in both WKY and SHR. Recovery of mechanical function of the heart during reperfusion following ischemia in SHR was better than that in WKY, while recovery of the high-energy phosphates level in SHR was less prominent than in WKY. It is postulated that hypertension has a deleterious effect on myocardial energy metabolism in ischemic heart, even when cardiac mechanical function is maintained.

Adenosine Triphosphate↗
PubMed1986

[Infarct size in patients with acute myocardial infarction estimated by emission computed tomography with technetium-99m pyrophosphate: relation to creatine phosphokinase release].

To evaluate the usefulness of single photon emission computed tomography (SPECT) with technetium-99m-pyrophosphate (99mTc-PYP) for estimating infarct size, we compared SPECT data with maximum creatine phosphokinase values. Background threshold was established in a series of phantom experiments. When a 40% cut-off was applied, the SPECT data most closely approximated actual phantom volumes. Therefore, the 40% cut-off level was used in the present study. In 10 patients with acute myocardial infarction, planar 99mTc-PYP myocardial scintigraphy and SPECT using a rotating gamma camera were performed two days after the initial myocardial infarction episode. The maximum creatine phosphokinase value (CPKmax) was also measured repeatedly following the episode. When the infarct size measured by SPECT using transaxial images and calculated by the pixel counts, it correlated very closely with CPKmax (r = 0.94). Most studies so far have reported that the CPKmax level reflects infarct size. We conclude that the infarct size as measured by 99mTc-PYP SPECT closely approximates the actual infarct size, and that this method is useful to determine the severity of infarcts clinically. Among the 10 patients in this series, three of five with infarcts greater than 60 ml died of pump failure. Therefore, we may be able to predict prognosis after accumulating more such cases and improving the methodology.

Aged↗
PubMed1986

[A double blind comparative study on the efficacy of S6472, cefaclor and amoxicillin, in the treatment of bacterial pneumonia].

The S6472 is a 4:6 mixture of 2 types of granules of cefaclor (CCL) coated with different films; one type of granules is soluble at low pH's and absorbed in the stomach while the other type is soluble at high pH's and absorbed in the intestine. The difference in absorption sites makes it possible to maintain blood concentrations of the drug at clinically efficient levels for a longer period of time compared with ordinary CCL. The efficacy, safety and usefulness of S6472 in the treatment of bacterial pneumonia was compared with those of ordinary CCL and of amoxicillin (AMPC) by the blind method. The patients entered in this trial were those who had bacterial pneumonia or lung abscess and were 16 years or above of age. The S6472 was given orally for 14 days at a daily dose of 1,500 mg (750 mg each after breakfast and supper), CCL was given at a daily dose of 1,500 mg (500 mg each after every meal), and AMPC at 2,000 mg (500 mg each after every meal and at the bedtime). To make the study blind, placeboes were matched with the test drug so that patients in every treatment group took 4 doses per day. Out of a total of 195 patients thus treated, 179 patients (55 in S6472 group, 62 in CCL group and 62 in AMPC group) were adopted for the evaluation by committee members while 185 patients (58 in S6472 group, 63 in CCL group and 64 in AMPC group) by controllers. When clinical results of the 3 treatment groups were compared, no statistically significant differences were observed in efficacy rates (cure rates), incidences of side effects nor abnormal findings of laboratory tests. From these results of this trial, it is concluded that oral administration of 750 mg of S6472 twice a day (1,500 mg per day) is as effective and useful as that of 500 mg of ordinary CCL 3 times a day (1,500 mg per day) or 500 mg of AMPC 4 times a day (2,000 mg per day) in the treatment of bacterial pneumonia or lung abscess.

Adolescent↗
PubMed1985

Isolation and characterization of cartilage proteoglycans immunoreactive with an antibody to skin proteodermatan sulfate core protein.

Low density proteoglycans showing cross-reaction with an antibody to skin proteodermatan sulfate (PDS) core protein were isolated from the bovine articular cartilage, by CsC1 density gradient centrifugation followed by repeated DEAE-cellulose chromatography. The size and amino acid composition of the core proteins of the immunoreactive proteoglycans, eluted at 0.25M and 0.5M NaC1 on DEAE-cellulose column, were quite similar to that of PDS. The glycosaminoglycan components of both proteoglycans were shown to be composed of a hybrid structure of chondroitin sulfate and dermatan sulfate, based on chondroitinase treatments followed by two-dimensional electrophoresis.

Amino Acids↗
PubMed1985

Biochemical and immunohistochemical studies on the scirrhous carcinoma of human stomach.

Tumor mass of the stomach from patients with scirrhous carcinoma was analyzed biochemically and immunohistochemically to elucidate whether or not infiltrating carcinoma cells are directly responsible for overproductions of collagen in the lesion. Collagen content per unit transverse section of the tumor was two to four times higher than the normal. Of particular interest was that the contents of hyaluronic acid and chondroitin sulfate were five to ten times higher than the normal, suggesting that cells in the lesion of the tumor are in an actively proliferating stage. Immunohistochemical observations using type-specific anti-collagen antibodies and anti-carcinoembryonic antigen antibody revealed that type IV collagen was diffusely distributed through the tumor stroma of submucosa and fragmented regions of muscle layer, along with dense fibrous components composed of type I and type III collagens. Stroma cells in the lesion were often stained with antibody to type IV collagen. In contrast, carcinoma cells were with antibody to type I collagen, but not with antibodies to type III and type IV collagen. Quantitative analysis of the collagen production by isolated stroma cells and undifferentiated (KATO-III) and highly differentiated (MKN-28) carcinoma cells in culture in the presence and absence of a combination of the conditioned medium of these cells has shown that the scirrhous carcinoma of stomach results from the "stroma reaction" of stroma cells induced by infiltrating malignant epithelium.

Adenocarcinoma, Scirrhous↗
PubMed1984

Olivary projections from the mesodiencephalic structures in the cat studied by means of axonal transport of horseradish peroxidase and tritiated amino acids.

By means of horseradish peroxidase (HRP) and autoradiographic methods, olivary projections from mesodiencephalic structures were studied in the cat. Following HRP injections in various parts of the inferior olive, many cells were labeled ipsilaterally in the nucleus of Darkschewitsch, the nucleus accessorius medialis of Bechterew, the nucleus of the fields of Forel, and the subnucleus dorsomedialis and ventrolateralis of the parvocellular red nucleus. Some labeled cells also occurred ipsilaterally in the suprarubral reticular formation and a few labeled cells in the interstitial nucleus of Cajal. After injection of tritiated amino acids in different parts of the mesodiencephalic region mentioned above, labeled fibers were found in different parts of the inferior olive, presenting a high degree of the topographic correlation within the mesodiencephalo-olivary projection, which was exclusively ipsilateral. That is, the nucleus of Darkschewitsch was found to project to the rostral half of the medial accessory olive and the dorsomedial cell column. There was mediolateral topographic relation in this projection. The nucleus accessorius medialis of Bechterew was found to project to the ventral lamella and the lateral part of the dorsal lamella as well as to small rostromedial part of the caudal half of the medial accessory olive. The subnucleus dorsomedialis and ventrolateralis of the parvocellular red nucleus projected to the rostral and caudal halves, respectively, of the medial part of the dorsal lamella. The subnucleus ventrolateralis of the parvocellular red nucleus also sent fibers to the lateral part of the ventrolateral outgrowth. The nucleus of the fields of Forel, suprarubral reticular formation, and interstitial nucleus of Cajal appeared to project to the caudal half of the medial accessory olive, the medial part of the ventrolateral outgrowth, the rostral part of the dorsal cap, and the caudal part of the dorsal accessory olive.

Animals↗
PubMed1984

Immunological and morphological properties of HBeAg subtypes (HBeAg/1 and HBeAg/2) in hepatitis B virus core particles.

A polypeptide of 21 500 mol. wt., structurally associated with hepatitis B virus core particles, was shown to have two kinds of HBeAg antigenicity (HBeAg/1 and HBeAg/2). This was revealed by transferring a single core peptide from polyacrylamide gels to nitrocellulose sheets (Western blotting), which reacted with anti-HBeAg/1 and anti-HBeAg/2. Selective discrimination of the two HBe antigens was achieved by radioimmunoassay (RIA). When highly purified core particles were incubated at 37 degrees C in a 0.1% SDS-0.1% 2-mercaptoethanol solution, only HBeAg/1 was released after 5 min incubation and the release of HBeAg/2 occurred only after prolonging incubation for 30 min. The course of degradation was also detected by CsCl density gradient centrifugation. These results indicate that HBeAg/1 is less closely associated with core particles than is HBeAg/2. Electron microscopy showed that the core particles from which HBeAg/1 was removed were more labile than the original preparation when incubated at 56 degrees C in aqueous solution, or at 37 degrees C in Sarkosyl solutions; when placed in 1 M-NaCl or -CsCl solution, the particles swelled to a larger diameter than untreated cores.

Electrophoresis, Polyacrylamide Gel↗