Search PubMed⌕ Search

Biomedical subjects

M Kanazawa

Publications and source records attributed to M Kanazawa.

332 records · Page 19Linked to original sources

Attenuation of live E. coli-induced acute lung injury by X-ray irradiation in guinea pigs.

Irradiation is suspected to injure inflammatory cells, such as neutrophils and mononuclear phagocytes, cells known to contribute to the development of acute lung injury (ALI). This study examined whether preexposure to x-ray irradiation modifies ALI induced by E. coli injected intravenously in guinea pig. Thirty animals were divided into two control and two irradiated subgroups: the first control group received saline only (n = 8), and the second control group received E. coli, 2 x 10(9)/kg body weight, suspended in saline (n = 6), IV. The first irradiated group received a single 12-Gy dose + saline (n = 6), and the second irradiated group received a single 12-Gy dose + E. coli (n = 10). The lung wet-to-dry-weight ratio (W/D) and 125I-albumin lung tissue/plasma ratio (T/P) were measured as markers of lung injury. W/D was significantly higher in the control E. coli group than in the other groups. T/P in the control E. coli group was also increased compared with T/P measured in the other groups. In the control E. coli group, a marked increase in bronchoalveolar lavage (BAL) neutrophils was observed compared with the control saline group. However, no significant difference in BAL neutrophil counts was observed between the control and irradiated E. coli groups. In contrast, BAL macrophages were significantly reduced in the irradiated E. coli groups compared with the control E. coli group. These findings suggest that x-ray irradiation attenuates E. coli-induced ALI in guinea pigs, an effect explained, at least in part, by a reduction in the number of alveolar macrophages.

Analysis of Variance↗

Epidermoid cyst in the temporomandibular joint after a dermal graft.

A very rare case of epidermoid cyst of the left temporomandibular join (TMJ) after a dermal graft inserted as the interposing material in the surgical correction of TMJ ankylosis is presented. Two years after the surgery, a cystic lesion the size of a walnut was observed in the TMJ region. The cyst contained an odorless, straw-coloured mucoid fluid and a wall lined by stratified squamous epithelium containing orthokeratin. It contained no hair follicles or sweat glands.

Ankylosis↗

Enzyme-linked immunosorbent assay of carbamoylphosphate synthetase I: plasma enzyme in rat experimental hepatitis and its clearance.

Carbamoylphosphate synthetase I (CPS I), a urea cycle enzyme, is located almost exclusively in the mitochondria of hepatocytes. The enzyme is unique in that it constitutes about 2-6% of total liver protein and is composed of a large subunit of 160 kD. We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for measurement of the enzyme in plasma using an antibody against the rat enzyme. In galactosamine-induced rat acute hepatitis, plasma concentration of CPS I that was 1-2 micrograms/ml blood before the treatment, increased up to 125 micrograms/ml blood in 24 h after the treatment and decreased to a near control level in 72 h. Plasma concentration of ornithine carbamoyl-transferase (OCT), another urea cycle enzyme, reached a maximum in 24 h and then decreased a little more rapidly than that of CPS I. On the other hand, alanine aminotransferase activity reached a maximum in 36 h and decreased to a normal level in 96 h. In immunoblot analysis, the native CPS I polypeptide of 160 kD and its fragments of 140 and 125 kD were detected 24-48 h after the treatment. When purified rat CPS I and bovine OCT were injected intravenously into rats, the enzymes disappeared from blood roughly exponentially with apparent half-lives of about 67 and 18 min, respectively. Development of an ELISA for human CPS I and determination of the serum enzyme in various liver diseases remain to be performed.

Acute Disease↗

Early ultrastructural changes in the central nervous system in Fukuyama congenital muscular dystrophy.

Electron microscopy of the central nervous system surface structure is described in two fetuses with Fukuyama congenital muscular dystrophy (FCMD). In addition to relatively large surface defects, many minute defects less than several micrometers in size associated with protrusion of glial cytoplasm were observed in the cerebrum. These findings were considered to represent early changes prior to cortical dysplasia. The basement membrane adjacent to the defects showed amorphous, wavy, or whorled configurations, and gradually disappeared. The glial cytoplasmic membrane seemed to be relatively well preserved in some areas where the basement membrane disappeared. On the other hand, both the basement membrane and cytoplasmic membrane became indistinct irregularly in areas without defects, including the spinal cord; similar lesions were found in the skeletal muscle. These observations confirm previous observations concerning defects of the pial-glial barrier of the brain surface, and may suggest the involvement of abnormal basement membrane or related structures, or both, in the genesis of the brain lesions of FCMD.

Adult↗

Noninvasive measurement of regional lung water distribution in healthy man and in pulmonary oedema.

A quasi steady-state noninvasive, radioisotopic technique for measuring regional lung water distribution in man is described. The method depends upon the dilution principle. 123I labelled human serum albumin (HSA) and sodium iodide (NaI) were injected intravenously, allowed to mix completely within the body fluids and then counted externally over the chest. The size of each compartment to which the markers are confined was calculated from the external count rate and the isotopic concentration of the marker in plasma. 123I-HSA was used to estimate intravascular water and 123I-NaI extracellular water. Ratio analysis of the differential attenuation of the two photoenergies of 123Iodine (29 keV, 159 keV) by the lung and chest wall was used to estimate the absolute amount of isotope in the lung, independent of chest wall contribution, after validation by phantom studies. Regional pulmonary plasma (PPVr) and interstitial (PIVr) fluid volumes in normal subjects were 7.1 +/- 1.4 and 7.6 +/- 1.3 ml.100 cm-3 lung (mean +/- SD; n = 13) at mid-tidal volume, respectively. In patients with the adult respiratory distress syndrome, PPVr and PIVr were 7.0 +/- 2.9 and 15.9 +/- 4.6 ml.100 cm-3 lung (n = 18), respectively. The pulmonary artery wedge (Paw) pressure was normal (12.5 +/- 2.5 mmHg; n = 5). In patients with pulmonary oedema due to left heart disease, PPVr and PIVr were 7.2 +/- 2.7 and 12.1 +/- 3.7 ml.100 cm-3 lung (n = 8), respectively. The mean Paw pressure in this group was high (28.5 +/- 3.9 mmHg).

Adult↗

Effect of systemic dexamethasone on extracellular amino acids, GABA and acetylcholine release in rat hippocampus using in vivo microdialysis.

In order to elucidate the mechanism of the cytotoxic effect of glucocorticoid on the rat hippocampus, we studied the effects of dexamethasone, a synthetic glucocorticoid, on neurotransmitter release from the hippocampus by in vivo microdialysis. Dexamethasone (10 mg/kg) was administered i.p. and the extracellular concentrations of the amino acids (glutamate, aspartate, glycine), GABA and acetylcholine were determined in the hippocampus of freely moving rats. Glutamate concentration increased by 20-25% after dexamethasone administration and this effect continued for 1 hour. The extracellular concentration of the other neurotransmitters, however, did not show any significant changes. From these results, we concluded that increased extracellular glutamate may be involved, at least in part, in the cytotoxic effect of glucocorticoid on hippocampal neurons.

Acetylcholine↗