Biomedical subjects
Publications and source records attributed to N Kuwahara.
The whole structure of platycodin D is found to be essential to stimulate the volumetric increase in the pancreatic exocrine secretion, while the prosapogenins prepared from platycodin D increased only protein output of pancreatic juice.
OBJECTIVES: Group II phospholipase A2 (PLA2) regulates eicosanoids and platelet activating factor (PAF) production and plays an important role in regulating critical mediators in inflammatory diseases such as trauma, sepsis and multiple organ failure. To elucidate the local effect of surgical trauma, we investigated the production of group II PLA2 at a local site after surgery. DESIGN AND METHODS: We utilized a radioimmunoassay to measure group II PLA2 levels in peritoneal exudates from the operative field and blood in patients who underwent gastrectomy. We also investigated the production of group II PLA2 in cells from peritoneal exudates by Northern blotting and immunocytochemistry. RESULTS: Immunoreactive group II PLA2 levels were significantly increased from 3 h after surgery and peaked at 12 h peritoneal exudates. However, serum group II PLA2 levels peaked at 24-48 h and decreased gradually after surgery, findings similar to levels of postoperative serum C-reactive protein (CRP). There was no significant correlation between group II PLA2 levels in peritoneal exudates and those in blood. Group II PLA2 mRNA was expressed at high level in cells from peritoneal exudates, by Northern blot analysis, but not those from blood. The localization of group II PLA2 protein was intense in neutrophils, as determined by immunocytochemistry. No group II PLA2 expression was observed in corresponding peripheral blood cells. CONCLUSIONS: After surgery, group II PLA2 is increased in peritoneal exudates prior to elevation in the blood circulation and is produced by neutrophils recruited and activated at a local site. Group II PLA2 produced in peritoneal exudates by neutrophils has an important role in the physiological and pathological states at a local site, after surgery.
Serum levels of group II phospholipase A2 (PLA2) have been reported to be associated with stage of disease in cancer patients. These levels are also related to the malignant potential in tissues, and are an important prognostic factor. We radioimmunoassayed group II PLA2 levels in pleural and peritoneal effusions from patients with various cancers. We also investigated the production of group II PLA2 in cells in effusions from cancer patients by Northern blotting, immunocytochemistry and in situ hybridization. Immunoreactive group II PLA2 levels were significantly higher in effusions from 47 patients with various cancers, compared with those in sera and cirrhotic ascites. There was no significant correlation between group II PLA2 levels in effusions and those in sera. Group II PLA2 mRNA was expressed at a high level in cells from effusions, by Northern blot analysis, but not in those cells from blood. The localization of group II PLA2 protein and mRNA was intense in carcinoma cells and CD68-positive macrophages, determined by immunocytochemistry and in situ hybridization. In addition, IL-6 and IL-8 levels were significantly higher in effusions, in comparison with those in sera from patients, suggesting that cancer cells and macrophages produce group II PLA2 by IL-6. These group II PLA2 levels are apparently significantly increased in effusions, and the carcinoma cells and macrophages produce group II PLA2, as noted in effusions from patients with various cancers.
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To diagnose hepatocellular carcinoma (HCC) functionally and immediately, we examined the usefulness of indocyanine green (ICG) injection during ultrasound-guided liver biopsy. Liver specimens were obtained after intravenous ICG injection by ultrasound-guided biopsy from 251 space-occupying lesions (SOL) in 136 patients. The tissues were immediately examined for ICG uptake using an infrared Vidicon camera and were also subjected to histopathological examinations. Of the 112 ICG-negative biopsy specimens, 105 were histologically diagnosed as HCC, 6 as dysplastic nodules (DN) and 1 as a regenerative nodule (RN). Of the 139 ICG-positive specimens, 18 were diagnosed as HCC, 1 as DN and 120 as RN. The sensitivity of the absence of ICG uptake (SEAIU), the specificity of the absence of ICG uptake (SPAIU), and the positive predictive value of the absence of ICG uptake (PPAIU) for the diagnosis of HCC were 85.3%, 94.5% and 93.8%, respectively. Of the 251 SOLs, 184 were less than 2 cm. SEAIU, SPAIU and PPAIU for the diagnosis of these small HCC were 85.3%, 94.5% and 91.4%, respectively. These results support the reliability of ICG injection during ultrasound-guided liver biopsy to diagnose even small HCC.
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Tissue PIVKA-II was examined in 32 hepatocellular carcinomas and 2 metastatic liver tumors using indirect immunofluorescence, and the results were compared with the size, histological grading and serum PIVKA-II level. The specificity of this method was confirmed by the disappearance of reactivity in PLC/PRF/5 cells after the addition of vitamin K to the culture medium. Positive PIVKA-II staining was observed as a clustered or a single cell pattern only in the HCC nodules, but not in the surrounding cirrhotic tissue. PIVKA-II staining was observed in all HCC groups regardless of histological grade. There was no relationship between PIVKA-II staining and the size of HCC. PIVKA-II was detected immunohistochemically even in small HCC of patients whose plasma PIVKA-II levels were below the detection limit. These results suggest that PIVKA-II production is a specific phenotype of HCC regardless of its histological grading and demonstrate that this immunofluorescent PIVKA-II staining is more sensitive and useful than plasma PIVKA-II assay for the diagnosis of HCC.
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The structures of hetero-oligosaccharides obtained by the action of transglycosylation of Arthrobacter sp. K-1 beta-fructofuranosidase, using sucrose as the fructosyl donor, and several mono- and di-sacchrides as the acceptors were investigated. The main transfer products to most reducing mono- and di-sacchrides were non-reducing oligosaccharides with a fructosyl residue linked to a hemiacetal hydroxyl group. In the presence of L-sorbose, the enzyme produced 2-O-beta-D-fructofuranosyl-alpha-L-sorbopyranoside as the major product. With D-galactose or L-arabinose, the enzyme produced not only non-reducing oligosaccharides, but also reducing oligosaccharides, which were identified as 3-O-beta-D-fructofuranosyl-D-galactopyranose and 4-O-beta-D-fructofuranosyl-L-arabinopyranose, respectively. When a non-reducing sugar such as methyl alpha-glucoside was used as an acceptor, the product formed had a fructosyl residue linked at the C6 hydroxyl group.
Jack bean alpha-mannosidase had a wide acceptor specificity and could transfer mannosyl residues to various acceptors such as D-fructose, L-arabinose, maltose, lactose, and sucrose. The structures of the transferred products of branched cyclodextrins (CDs) (glucosyl-beta CD, maltosyl-alpha CD, and maltosyl-beta CD) were found to be alpha-D-mannosyl-(1-->6)-alpha-D-glucosyl-(1-->6)-beta CD, alpha-D-mannosyl- (1-->6)-alpha-D-glucosyl-(1-->4)-alpha-D-glucosyl-(1-->6)-alpha CD and alpha-D-mannosyl-(1-->6)-alpha-D-glucosyl-(1-->4)-alpha-D-glucosyl-(1--> 6)- beta CD, respectively. Almond alpha-mannosidase also produced the same transmannosylated products of branched CDs.
Transgalactosylated derivatives of cyclodextrins (CDs) and glucosyl and maltosyl CDs (G1- and G2-CDs) were synthesized by alpha-galactosidases from coffee bean and Mortierella vinacea (M. vinacea). The structures of the transfer products were analyzed by FAB-mass, 13C-NMR and methylation. Coffee bean alpha-galactosidase transferred a galactosyl residue not only to side chains of G1-CDs and G2-CDs, but also directly to CD rings. M. vinacea alpha-galactosidase transferred a galactosyl residue only to side chains of G2-CDs.
The activity of O6-methylguanine-DNA methyltransferase (O6-MT), which removes O6-methyl residues from O6-methylguanine-DNA leading to cell death, has been reported to correlate with sensitivity to nitrosoureas used for chemotherapy of gliomas. We determined O6-MT activity in tumors and matched brain tissue from patients with gliomas. Histological diagnoses were: six malignant astrocytomas, two glioblastomas, two oligodendrogliomas, one ependymoma, and one medulloblastoma. In all cases but one, the activity ranged widely from 39 to 258 fmol/mg protein extract. The wide range of activity of the tumor tissue may indicate varying degree of sensitivity to nitrosoureas. The activity of brain tissue, available from the peritumoral region of five cases, varied between 38 to 415 fmol/mg. Four of the five regions showed a higher value than the respective tumor, and one showed a lower value.
Transgalactosylated products of branched cyclodextrins (glucosyl-alpha CD, -beta CD, -gamma CD, and maltosyl-alpha CD, -beta CD, -gamma CD) were synthesized by beta-D-galactosidases from Bacillus circulans and Penicillium multicolor using lactose as a donor substrate and branched CDs as acceptors. Eighteen beta-D-galactosylated branched CDs were isolated and purified by HPLC. Their structures were elucidated by FABMS and 13C NMR spectroscopies, and methylation analysis. The chromatographic behavior of these novel heterogeneous branched CDs on three HPLC columns of different separation modes was compared.
Autoradiographic study of (14C-methyl)-L-methionine with brain tumor bearing rats aimed at an elucidation of the mechanism of tracer accumulation in the protein synthesis of tumor. Twice as much tracer accumulated in the tumors compared as in the contralateral gray matter (nontumor region) at 90 min post intravenous injection. The protein-bound fraction of the tumors, expressed as acid-insoluble fraction (AIF), was 1.7 +/- 0.6 (mean +/- standard deviation, n = 6), significantly higher than that (0.8 +/- 0.2) of the nontumor region (p < 0.05 by the Mann-Whitney test). The tumor AIF comprised 82.3 +/- 9.2% of the total amount of the tracers accumulated in the tumors. The protein synthesis inhibitor cycloheximide reduced the tracer uptake and the AIF of the tumors to an almost same level as the nontumor region. These findings indicate that metabolic acceleration of protein synthesis may be a main reason for the high accumulation of (14C-methyl)-L-methionine in tumor.
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