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Biomedical subjects

K Kojima

Publications and source records attributed to K Kojima.

At least 415 records · Page 23Linked to original sources

The presence of two types of gene that encode the chlorophyll a/b-binding protein (LHCPII) and their light-independent expression in pine (Pinus thunbergii).

A cDNA clone (pPDLHC3117) for LHCPII of pine (Pinus thunbergii) was isolated and sequenced. From a comparison of the deduced amino acid sequence with those of proteins from other seed plants, pPDLHC3117 was identified as encoding a type I LHCPII. Specific probes for genes for type I and type II LHCPII were made from pPDLHC3117 and a type II cDNA (pPDLHC2176), respectively. Northern blotting with the specific probes showed that both types of LHCPII were expressed in dark-grown seedlings of pine.

Amino Acid Sequence↗

A murine model of experimental autoimmune lens-induced uveitis using Klebsiella O3 lipopolysaccharide as a potent immunological adjuvant.

Experimental autoimmune uveitis and finally panophthalmitis could be produced in mice by repeated immunization of syngeneic eyeball extract mixed with Klebsiella O3 lipopolysaccharide (KO3 LPS) as a powerful immunological adjuvant. No ocular lesions were produced in mice given eyeball extract emulsified in complete Freund's adjuvant (CFA), KO3 LPS alone or eyeball extract alone. Histopathological changes in the ocular lesions at the early stage after the second or tertiary immunization were characterized by infiltration with inflammatory cells in the ciliary body and iris. The iridocyclitis was followed by extensive infiltration of polymorphonuclear leucocytes (PMN) into the cornea, lens and the surrounding tissues after repeated immunization. Finally, these areas were replaced by granulomatous tissues infiltrated with mononuclear cells. On the other hand, the structure of the retina and sclera was partially preserved. Those mice exhibited production of autoantibodies and development of the delayed-type hypersensitivity (DTH) to syngeneic eyeball extract. Moreover, ocular lesions could be produced in normal recipient mice by transfer of sensitized lymphocytes from hyperimmunized mice. Therefore, it was suggested that the ocular lesions produced by repeated immunization with the mixture of eyeball extract and KO3 LPS were due to the autoimmune mechanism. This might be useful to model immunological phenomena in the pathogenesis of human phacoantigenic uveitis.

Adjuvants, Immunologic↗

[Comparison between ELISA and culture method for detection of Helicobacter pylori].

Detection of Helicobacter pylori (H. pylori) by ELISA was compared with that by the culture method in 115 patients with gastroduodenal diseases. Both the sensitivity and specificity were more than 85% for patients with histological gastritis with neutrophil infiltration. This indicated that the detection of H. pylori by ELISA is useful for the diagnosis of H. pylori-related gastritis. Although the sensitivity between the ELISA and culture method was 85%, the specificity was 58.8%. The false negative detection may have been caused by a sampling error during the endoscopic biopsy.

Adult↗

Two cases of Goodpasture's syndrome--clinicopathological studies and relapse.

The requirements for a diagnosis of Goodpasture's syndrome (GPS) include: (1) the presence of glomerulonephritis, (2) alveolar bleeding, and (3) the presence of anti-glomerular basement membrane (anti-GBM antibody). Among Japanese case, the 2 patients reported here were rare in that they satisfied all of these requirements. In case 1 (a 40-year-old male), the disease developed with initial signs of proteinuria and hematuria. The patient developed hemoptysis after hospitalization. The interval from onset to hospitalization was 38 days. The serum creatinine (CRN) level was 3.6 mg/dl on admission. The pathological findings were rated as full-circumferential, cellular crescentic nephritis, and the patient did not display oliguria. The renal and pulmonary impairments in this case were markedly improved by glucocorticoid (prednisolone PSL, 60 mg/day), cyclophosphamide therapy (50 mg/day) and plasma exchange (PE 10 times). In case 2 (a 58-year-old male), the initial signs developed as proteinuria and hematuria, followed by rapidly progressive renal functional deterioration and hemoptysis occurred. Compared to Case 1, the interval from onset to hospitalization was longer in Case 2 (125 days) and the CRN level was also higher (10.7 mg/dl). Case 2 was rated as full-circumferential, fibrous crescentic nephritis, and the patient was oliguric. Although the pulmonary impairment was reduced by pulse therapy and 10 PEs, recovery of renal function has not been achieved, still necessitating maintenance hemodialysis at present. In case 1, the disease relapsed at 4.5 years after remission, presenting with aggravated renal function and hemoptysis. In this case, low-dose PSL therapy had been discontinued at 3 months before the relapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Selective removal of beta 2-microglobulin from plasma specimens of long-term hemodialysis patients by high-performance immunoaffinity chromatography.

We examined the suitability of high-performance immunoaffinity chromatography (HPIAC) for removing beta 2-microglobulin (beta 2-MG) from plasma of patients (n = 26) undergoing long-term hemodialysis. We used immobilized antibody to beta 2-MG to prepare an immunoaffinity column with a 0.5-mL bed volume. Plasma samples of 0.5 mL were chromatographed at a flow rate of 0.5 mL/min and pressures < 7 kg/cm2. Although only a small amount of beta 2-MG can be removed with a conventional dialyzer, 92.1% +/- 0.4% of the globulin could be removed by HPIAC. The column could be reused after acid elution. After 50 cycles the efficiency of beta 2-MG trapping was 73% of the original efficiency.

Adult↗

Carbohydrate-binding proteins in bovine kidney have consensus amino acid sequences of annexin family proteins.

Ca(2+)-dependent carbohydrate-binding proteins were purified from bovine kidney extracts. Upon SDS-polyacrylamide gel electrophoresis under nonreducing conditions, the purified fraction gave doublet protein bands corresponding to 33 kDa (p33) and 41 kDa (p41). Under reducing conditions, a single protein band (p33) was observed. p33 and p41 were submitted to proteolytic digestion with endoproteinase Lys-C, the peptides produced were separated by reversed-phase high performance liquid chromatography, and their amino acid sequences were determined by an automated gas-phase protein sequenator. Most of the resulting partial amino acid sequences of these proteins were strikingly homologous to annexin IV, an annexin family protein, i.e. Ca2+/phospholipid-binding proteins, especially in the consensus sequences. In the presence of Ca2+, both proteins bound to vesicles composed of phosphatidylserine and phosphatidylethanolamine, but not phosphatidylcholine. These results indicated that p33 and p41 are members of annexin family proteins.

Amino Acid Sequence↗

Efficient purification of a full length and biochemically active p110Rb, the retinoblastoma gene product.

Rb protein was purified from recombinant baculovirus-infected Sf9 cells to apparent homogeneity by a simple solubilization and by immunoaffinity column chromatography. It was mainly obtained as p110Rb, the underphosphorylated form of the Rb protein family. This p110Rb was shown to form a specific complex in vitro with SV40 Tag and to bind to double or single stranded DNA. It could also affect Tag helicase activity in a biphasic-dose dependent manner, due to these two biochemical functions. This purification procedure provides sufficient amounts of native Rb protein to further elucidate its role as an anti-oncogene protein and a negative regulator of the cell cycle.

Animals↗

[MR imaging of thymoma--comparison with CT, operative, and pathological findings].

Twenty-six patients with thymoma, who had magnetic resonance (MR) imaging and computed tomography (CT) before surgery, were studied. Twenty-six thymomas were classified into 11 non-invasive thymomas (Masaoka's clinical stage I) and 15 invasive thymomas (stage II, III, and IV). On MR imaging compared with histological findings, low signal intensity rim of the tumor was corresponded to fibrous capsule of the tumor, and linear and/or reticular low signal intensity lines in the tumor were corresponded to the fibrous septae dividing thymoma into lobules. The detectability of these findings by MR imaging was superior to that by CT. Margin of the tumor was smooth in non-invasive thymoma rather than invasive thymoma. The diagnostic accuracy of invasion to vessel, and pleura or lung on MR imaging and CT was compared with operative and histological findings. MR imaging was same as CT in its ability to detect tumoral invasion to vessel, and slightly superior to pleura or lung. In conclusion MR images clearly show the findings corresponding to pathologic specimens, and MR imaging combining with CT is useful to differentiate non-invasive thymoma to invasive thymoma.

Adult↗

Improved affinity chromatographic purification of D-mannose-N-acetyl-D-glucosamine-specific lectin from the bark of Sophora japonica eliminating the loss by sugar specific self-aggregation.

A novel D-mannose-N-acetyl-D-glucosamine-specific lectin of Sophora japonica bark, B-SJA-II, which showed self-aggregation based on sugar specificity, was purified by affinity chromatography on maltamyl-Sepharose subsequent to chromatographic separation on lactamyl-Sepharose to remove a major D-galactose-N-acetyl-D-galactosamine specific lectin, B-SJA-I. However, the yield of this method was low as a result of the sugar-specific precipitation and binding to other glycoproteins. A modified method was developed to circumvent this problem. All the purification procedures, except for the final chromatographic separation, were carried out in the presence of the haptenic sugar and the sugar-specific adsorption of B-SJA-II onto the adsorbent was carried out in a dialysis bag by gradually removing the sugar. This method gave a yield eight times higher than the original method.

Acetylation↗

Affinity purification and affinity characterization of carbohydrate-binding proteins in bovine kidney.

Ca(2+)-dependent carbohydrate-binding proteins were purified from bovine kidney by two-step affinity chromatography on fetuin and heparin columns and subsequent anion-exchange high-performance liquid chromatography. On sodium dodecyl sulphate-polyacrylamide gel electrophoresis, the purified fraction gave two protein bands corresponding to proteins of relative molecular mass 33,000 (p33) and 41,000 (p41), respectively. Although the proteins had no haemogglutinating activities towards human and rabbit erythrocytes, their carbohydrate-binding activity was examined by a newly developed method using horseradish peroxidase (HRP) and/or biotin-labelled glycoconjugates as affinity probes. They could bind in a Ca(2+)-dependent manner to labelled fetuin and heparin in a specific and dose-dependent manner by solid-phase assay after immobilization on plastic plate surface. Inhibition assay of the binding revealed that N-acetylneuraminic acid is the most potent inhibitor of the proteins among the monosaccharides tested. Fucoidin and heparan sulphate most strongly inhibited the binding of the proteins to labelled heparin. Direct binding assay to acidic glycolipids prepared from bovine kidney showed that the proteins react with the ganglioside fraction but not with sulphatide [Gal(3-SO4) beta 1-1Cer]. These results indicated that the purified proteins have a significant affinity to charged oligosaccharides linking to glycoproteins, glycolipids and charged polysaccharides in a Ca(2+)-dependent manner.

Amino Acids↗

[Prediction for effectiveness of steroid pulse therapy by MRI in Graves' ophthalmopathy].

Fifteen patients with Graves' ophthalmopathy (GO) were treated with intravenous methylprednisolone (steroid pulse therapy, 1g daily for 3 days a week, 2-4 times) and followed up by ophthalmological assessment and magnetic resonance imaging (MRI). The signal intensity of enlarged eye muscle and retrobulbar fat was examined with MRI at 0.5T with short inversion time inversion recovery (STIR) sequences. The signal intensity of eye muscle and retrobulbar fat tissue in STIR was evaluated as the ratio to cerebral substantia alba (signal intensity ratio). The thickness of enlarged eye muscle was measured by T1-weighted coronal images. The signal intensity ratios of enlarged eye muscle of GO patients were significantly higher than those of eight normal subjects. Although the signal intensity ratios of muscle and retrobulbar fat before therapy were not related to the severity of clinical findings of GO assessed by ophthalmopathy index, the initial signal intensity ratios of eye muscle and retrobulbar fat of ten patients with improved clinical findings of GO after steroid pulse therapy tended to be higher than those of five patients without improvement by the therapy. After the therapy the signal intensity ratios of muscle and retrobulbar fat were significantly decreased in ten patients with favorable response. Our data suggested that high signal intensity in STIR may reflect edema caused by acute inflammation associated with GO. In conclusion, MRI may be a useful tool for determining the indication and prognosis of steroid pulse therapy. We strongly recommend measuring the signal intensity of eye muscle as well as muscle thickness in MRI to evaluate the activity of GO.

Adipose Tissue↗

Structure of the pine (Pinus thunbergii) chlorophyll a/b-binding protein gene expressed in the absence of light.

A gene for chlorophyll a/b-binding protein (cab) of pine (Pinus thumbergii) was isolated and sequenced. The gene (cab-6) contains an intron at a position equivalent to the type II cab genes of angiosperms. Transcript mapping analyses show that the amount of the mRNA in the dark is about half of that in the light. The cab-6 gene is expressed in dark-grown seedlings at a very high level, differing from angiosperm cab genes which are induced by light. The cab-6 gene typifies the coniferous plant cab genes in light-independent gene expression.

Amino Acid Sequence↗

Relapsing acute disseminated encephalomyelitis associated with chronic Epstein-Barr virus infection: MRI findings.

A 25-year-old women had a fever, left cervical lymphadenopathy, neurological symptoms and signs, CSF pleocytosis and persistent high serum antibodies to the Epstein-Barr virus (EBV); she had a recurrence 1 year later. She was thought to have relapsing acute disseminated encephalomyelitis associated with chronic EBV infection. MRI revealed abnormalities, mainly in the right basal ganglia and left midbrain. At the time of the recurrence, further abnormalities appeared in the opposite basal ganglia and right cerebral white matter.

Adult↗

Successful treatment of neonatal aneurysmal dilatation of the vein of Galen: the role of prenatal diagnosis and trans-arterial embolization.

We report a neonate with aneurysmal dilatation of the vein of Galen diagnosed prenatally by color Doppler sonography and MRI at 37 weeks' gestation. The child was treated by transarterial embolization of micro-coils 2 and 8 days after birth. The aneurysmal dilatation of the vein of Galen markedly decreased after embolization and the patient is developing normally at 2 years 5 months of age. Prenatal diagnosis and early intervention by transarterial embolization produced in a good outcome in this patient.

Adult↗

Ion-spray mass spectrometric analysis of glycosaminoglycan oligosaccharides.

Oligosaccharides from hyaluronic acid and chondroitin 6-sulfate were prepared by digestion with testicular hyaluronidase and separated according to their degree of polymerization by gel-permeation chromatography. These materials were successively analyzed by negative-mode ion-spray mass spectrometry with an atmospheric-pressure ion source. An ion-spray interface was used to produce ions via the ion evaporation process, producing mass spectra containing a series of molecular species carrying multiple charges. Using two adjacent multiply charged molecular ions, the exact molecular weights up to the tetradecasaccharide were calculated with a precision of +/- 1 dalton. This type of mass spectrometry was also demonstrated to be feasible for the analysis of mixtures of oligosaccharides, including tetra-, hexa-, octa- and decasaccharides, from hyaluronic acid or chondroitin 6-sulfate without separation. Ion-spray mass spectrometry was thus shown to be applicable to the structural analysis of oligosaccharides from glycosaminoglycans.

Animals↗

Substitution of p- and o-hydroxyphenyl radicals at the 8 position of purine nucleosides by reaction with mutagenic p- and o-diazoquinones.

Incubation of 2'-deoxyadenosine (dAdo), 2'-deoxyguanosine (dGuo), adenosine, guanosine (Guo), thymidine, deoxycytidine with p- and o-diazoquinones, mutagens produced by the reaction of phenol and nitrite, at pH 7 and 37 degrees C resulted in a decrease of each nucleoside depending upon the concentration of the diazoquinones. pD-dAdo, pD-dGuo and pD-Guo were isolated from the reaction mixtures of dAdo, dGuo and Guo, respectively, with p-diazoquinone at pH 9.5, and oD-dGuo was from the mixture of dGuo and o-diazoquinone at pH 9.5. The products were identified as 8-(p-hydroxyphenyl)- and 8-(o-hydroxyphenyl)-purine nucleosides by 1H- and 13C-nuclear magnetic resonance spectra, secondary ion mass spectrum, ultraviolet absorption spectrum and elemental analysis. p- and o-Diazoquinones may be converted into p- and o-hydroxyphenyl radicals, respectively, which in turn attack the 8 position of the purine nucleosides. The mutagenicity of these diazoquinones may be partly due to the radical reactions.

Adenosine↗

DNA strand breakage by hydroxyphenyl radicals generated from mutagenic diazoquinone compounds.

The mutagenic diazoquinone compounds p-diazoquinone (p-DQ), o-diazoquinone (o-DQ) and 3-diazo-N-nitrosobamethan (D-BM) cleaved the phosphodiester bond of lambda DNA, phi X174 RFI DNA and M13mp8ss DNA. p-DQ also cleaved the phosphodiester bond of bis(p-nitrophenyl)phosphate. The breakage of the phosphodiester bond was inhibited by the antioxidant butyl hydroxyanisole (BHA), ethanol, the spin trapping agent DMPO, cysteine and 2-mercaptoethanol. While incubation of p-DQ and o-DQ alone gave p-hydroquinone and catechol, respectively, incubation of these compounds in the presence of BHA and ethanol gave phenol in large yields. Incubation of p-DQ and o-DQ with the spin trapping agents DMPO and PBN gave spin adducts assignable as p- and o-hydroxyphenyl adducts, respectively. The breakage of the phosphodiester bond of DNA by the diazoquinone compounds is suggested to be due to the hydroxyphenyl radicals generated during incubation.

Bacteriophages↗