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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 973 records · Page 54Linked to original sources
PubMed1988

Cerebral microvascular architecture following experimental cold injury.

The sequential changes in microvascular architecture following local cold injury in rat brains were studied post mortem by scanning electron microscopy and the vascular casting method. The findings were compared with the results of immunohistochemical studies of injured endothelial cells using the bromodeoxyuridine (BUdR) and anti-BUdR monoclonal antibody technique. Repair of the microvascular architecture had begun by the 3rd day after injury, with hematogenous cells and reactive astrocytes present in the edematous brain participating in the regenerative process. The normal microvascular architecture was reconstructed starting from the edge of the lesion nearest to the brain surface. On the other hand, in the most severely injured part of the brain surface, newly formed microvascular architecture appeared, resembling that of the developing fetal and newborn rat cortex. Seven days after injury, the entire microvascular architecture in the region of the lesion had been reconstructed.

Animals↗
PubMed1988

[Cerebellar ganglioglioma: a case report].

A case of cerebellar ganglioglioma is reported. A 22-year-old female was admitted to the Kurume University Hospital on August 19, 1985, suffering from headache, vomiting and gait disturbance. On admission, neurological examination revealed staggering gait and the right cerebellar ataxia showing dysmetria and dysdiadochokinesis. Mild choked disc in the right fundus was also noted. Plain CT scan showed the low-density area involving the right cerebellar hemisphere and the part of the vermis with internal hydrocephalus. Enhanced CT scan showed the high-density area adjacent to the low-density area suggesting a mural nodule. A vertebral angiogram in the arterial phase showed an expansive lesion in the posterior fossa and the tumor stain, which was also visualized in the venous phase. An emergency suboccipital craniectomy was then performed. With opening the tense dura mater, the cyst formation was noted and 30 ml of xanthochromic fluid was then aspirated. A well demarcated mural nodule was noted in the lateral wall of the cyst. The nodule was then extirpated in toto. The hypertrophy of the cerebellar cortex was not observed. Histologically, the tumor was consisted of nerve fiber, glial fiber and neuronal cells. Its architecture was differed distinctly from that of hamartomatous diffuse hypertrophy of the cerebellar cortex (Lhermitte-Duclos' disease). Immunohistochemically, the neuronal cells revealed positive staining for NSE and S-100, and the glial cells displayed positive staining for GFAP, S-100. The authors reviewed previously reported eleven cases of cerebellar ganglioglioma including the present case. These results showed that cerebellar gangliogliomas have some characteristic clinical features among general intracranial gangliogliomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[The clinical significance of murine monoclonal antibody (1H1) prepared against human pancreatic cancer cell line BxPC-3].

A new murine monoclonal antibody (1H1) was prepared by immunizing mice i.p. with human pancreatic cancer cell line (BxPC-3). The antibody reacted with 8 of 48 cultured cell lines that were all adenocarcinoma. Thin sections of normal and cancerous tissues were examined by immunoperoxidase staining. Thirty-nine of 48 (81%) pancreatic cancers, 11 of 23 (48%) gastric cancers, 12 of 18 (67%) colorectal cancers, 9 of 19 (48%) breast cancers, 2 of 5 (40%) lung cancers and 2 of 2 (100%) duodenal cancers were stained positively, but 5 islet cell tumors, 3 esophageal cancers and 2 hepatomas were not stained positively. Normal gastro-intestinal tract of adult or fetus was stained weakly or hardly stained. SDS-PAGE showed that 1H1 antigen recognized by 1H1 Mab had a relative molecular weight of over 400 K. Da. Immunoelectron microscopical study has shown that the antigen recognized by 1H1 antibody was localized in the cell membranes of the BxPC-3 cells. 1H1 antigen was found to be present in culture-spent medium of BxPC-3 cells by ELISA. Thus, 1H1 antibody may be useful for early detection of pancreatic cancers.

Adenocarcinoma↗
PubMed1988

[Cerebral circulation and oxygen metabolism in children's "moyamoya" diseases].

Regional (r) CBF, rOEF, rCMRO2, rCBV in five cases of "moyamoya" disease in children were studied with PET scan, using 15O steady-state methods. All cases showed ischemic symptoms such as TIA, RIND and minor stroke. Intervals from the latest ictus to PET ranged from 3 days to 3 years 6 months. Control data were obtained through PET studies in 8 normal volunteers. Physiological parameters described above, in cerebral gray matter, white matter and basal ganglia were calculated and were carefully compared with normal control. Apparently low density area in X-ray CT were excluded from this analysis. Although rCBF showed a little bit higher value in all gray, white and basal ganglia, it was not statistically significant. rCBV of "moyamoya" disease significantly increased in gray, white and basal ganglia. The calculated value of CBF/CBV is considered to be an index of perfusion pressure and is the reversed value of transit time. This value was significantly decreased in "moyamoya" disease in every three region. Under the normal autoregulation, further decrease of perfusion pressure initiate increase of rOER and also decrease of rCBF. In spite of reduction of CBF/CBV, rOER was not significantly increased in every three region. Hence the cerebral circulation in children's "moyamoya" disease of ischemic type appears to be characterized by the mild decrease of perfusion pressure, dilated resistant vessels and prolonged circulation time.

Adolescent↗
PubMed1987

Improvement of chemical analysis of antibiotics. XIII. Systematic simultaneous analysis of residual tetracyclines in animal tissues using thin-layer and high-performance liquid chromatography.

A simultaneous analytical system for residual tetracycline antibiotics (TCs) in animal tissues including liver has been developed. This system consists of three methods using Baker 10 C18 clean-up followed by high-performance liquid chromatography (method A), thin-layer chromatography (TLC)-UV densitometry (method B) and TLC with spray reagents (method C). Methods A and B were established for the precise determination of TCs and method C for universal screening. The recoveries from beef liver fortified at the level of 1.0 ppm and their coefficients of variation were 60.5-83.3% and 2.3-3.9% (method A) and 58.1-92.8% and 1.0-3.7% (method B), respectively. The detection limits in animal tissues were 0.01 ppm (method A) and 0.1 ppm (methods B and C). The time required for the analysis of four samples was 2.5-3 h with each method.

Animals↗
PubMed1987

Characterization of a protein containing D-aspartic acid in aged mouse lens.

A protein containing D-aspartic acid (D-Asp) was isolated from water insoluble (WI) fraction of naturally aged mice lens. The molecular weight of this protein was estimated to be about 10000 by gel permeation chromatography. High content of serine and glycine was noteworthy and the two amino acids occupy about 50 % of the total amino acids in the protein containing D-Asp.

Aging↗
PubMed1987

Improvement of chemical analysis of antibiotics. XII. Simultaneous analysis of seven tetracyclines in honey.

An analytical system for the simultaneous determination of residual oxytetracycline, tetracycline, chlortetracycline, doxycycline, methacycline, demethylchlortetracycline and minocycline in honey has been established by a combination of simple thin-layer chromatographic (TLC) and precise high-performance liquid chromatographic (HPLC) methods. In this system, screening by TLC can detect tetracyclines (TCs) at a level of 0.1 ppm in honey without the need for special equipment, and the quantitative method by HPLC can determine TCs with good recovery (83.7-99.6%) and coefficient variation (0.9-4.3%).

Chromatography, High Pressure Liquid↗
PubMed1987

Improvement of chemical analysis of antibiotics. XI. Simultaneous fluorodensitometric determination of polyether antibiotics.

A simultaneous determination of three polyether antibiotics, salinomycin, monensin and lasalocid, was established by silica gel and RP-18 high-performance thin-layer chromatography (HPTLC) using 18,19-dihydrosalinomycin and 18,19-dihydro-20-ketosalinomycin as internal standards. Fluorescent derivatives of the polyethers were prepared by reaction of their sodium salts with 1-bromoacetylpyrene and Kryptofix 222 in acetonitrile. A silica gel HPTLC plate with carbon tetrachloride-ethyl acetate-acetonitrile (50:5:10) as a solvent system and a RP-18 HPTLC plate with dichloromethane-ethyl acetate-acetone-acetonitrile (15:2:1:55) gave satisfactory separations of the five pyrenacyl esters of salinomycin, monensin, lasalocid, 18,19-dihydrosalinomycin and 18,19-dihydro-20-ketosalinomycin. Under these conditions the internal standard 18,19-dihydrosalinomycin was found to be suitable for the simultaneous determination of salinomycin and monensin, and 18,19-dihydro-20-ketosalinomycin for lasalocid. A linear relationship was obtained between the fluorescence intensity and the amount of each antibiotic in the range 2-14 ng. The detection limit of the three antibiotics was 100 pg.

Chromatography, Thin Layer↗
PubMed1987

Improvement of chemical analysis of antibiotics. X. Determination of eight tetracyclines using thin-layer and high-performance liquid chromatography.

Analytical methods for eight tetracyclines (TCs) were established using silica gel high-performance thin-layer chromatography (HPTLC), reversed-phase thin-layer chromatography (RP-TLC) and high-performance liquid chromatography (HPLC). Good separations of eight TCs were obtained using chloroform-methanol-5% disodium ethylenediaminetetraacetate solution (65:20:5) (lower layer) and methanol acetonitrile 0.5 M oxalic acid solution (1:1:4) (pH 3.0) on silica gel HPTLC and C8 TLC plates, respectively. A combination of HPTLC and RP-TLC made possible the identification of the eight TCs. Each calibration graph was linear between 0.1 and 1.0 microgram using UV densitometry except for rolitetracycline. For detection reagents, the diazonium salts including Fast Violet B gave variously coloured spots with the eight TCs and good sensitivities were obtained except with minocycline. In HPLC, the simultaneous analysis of the eight TCs on a C8 column was possible using methanol-acetonitrile-0.01 M oxalic acid solution (1:1.5:7) adjusted to pH 3.0 as the mobile phase. A linear relationship was obtained between 1.0 and 10 ng using the usual sample preparation except for rolitetracycline. The direct determination of rolitetracycline was possible using tetrahydrofuran, dimethyl sulphoxide and the mobile phase as solvents for preparation of the sample. For the determination of residual rolitetracycline, it was effective to measure the amount of rolitetracycline as tetracycline by HPLC, HPTLC and RP-TLC after conversion of rolitetracycline to tetracycline by incubating for 5 min in methanol at 50 degrees C.

Anti-Bacterial Agents↗