Biomedical subjects
K Iriyama
Publications and source records attributed to K Iriyama.
[An adult case of HBV nephropathy with positive HBeAg on glomerular capillary wall after seroconversion to HBeAb in serum].
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Allopurinol inhibits uric acid accumulation in the rat brain following focal cerebral ischemia.
Uric acid (UA) in the rat brain was measured by HPLC with an electrochemical detector following focal ischemia. At 24 h after the operation, the UA level in the ischemic center was 105.47 +/- 8.39 nmol/g tissue, whereas it was 8.36 +/- 1.86 in the sham-operated group. Allopurinol, xanthine oxidase inhibitor, almost completely inhibited this UA accumulation. These data demonstrate that the UA increase in the ischemic brain is due to the xanthine oxidase reaction.
Is extensive lymphadenectomy necessary for surgical treatment of intramucosal carcinoma of the stomach?
This study was undertaken to elucidate those histological and gross features associated with gastric carcinoma that can be adequately treated by gastrectomy with less aggressive lymphadenectomy. The frequency of metastasis to the lymph nodes was analyzed in 514 cases of resected, solitary, gastric carcinomas. The frequency of metastasis to the lymph nodes increased in proportion to the increase in the extent of penetration by the cancer into the gastric wall. Lymph nodes were not involved in cases of intramucosal carcinoma of the intestinal type, by Laurén's histological classification. By contrast, metastasis to the lymph nodes was observed in cases of intramucosal carcinoma of the diffuse type, by Laurén's classification. We conclude that extensive lymphadenectomy is not mandatory for patients with intramucosal carcinoma of the stomach of the protruded type, since the lymph nodes do not become involved in this type of gastric carcinoma.
Glutathione-dependent inactivation of sodium-dependent phosphate transport across rat renal brush-border membrane.
Thiol/disulfide is fundamental in protein function; we previously observed an inhibitory effect of thiol oxidants on the Na-dependent phosphate (Pi) uptake into renal brush border membrane vesicles (BBMV). We examined whether oxidation of glutathione (GSH) is involved in the mechanism. Vesicular thiols were measured by liquid chromatography. BBMV were incubated with reagents before an influx of Pi. Diamide (5 mM) reduced the capacity of the Pi uptake. Subsequent treatment with dithiothreitol (5 mM) blocked the inhibitory effect of diamide. Vesicular GSH was not modified only by the incubation, whereas it was oxidized by the treatment with diamide, and reduced by dithiothreitol. Furthermore, in vivo treatment with cAMP provided GSH-depleted BBMV without any influence on Pi uptake. Diamide did not inhibit the transport of Pi into GSH-depleted vesicles, but it did inhibit the uptake when GSH was introduced into the vesicles. In conclusion, a GSH-dependent mechanism is involved in the inhibitory effect of diamide on sodium-dependent Pi transport across the renal brush-border membrane.
[Changes in xanthine and uric acid in rat brain after middle cerebral artery occlusion].
Xanthine and uric acid, products of purine metabolism, were measured by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection in rat forebrain following focal cerebral ischemia. Focal cerebral ischemia was induced in the rat by permanent occlusion of the left middle cerebral artery (MCA). Sprague-Dawley rats were anesthetized with halothane inhalation and left MCA was occluded via trans-retro-orbital approach. Normal and sham-operated rats were used as control animals. The animals were decapitated 2 (MCA = 5, Sham = 5), 4 (MCA = 7, Sham = 6), 8 (MCA = 5, Sham = 5), and 16 (MCA = 6, Sham = 6) hours or 1 (MCA = 5, Sham = 5), 2 (MCA = 6, Sham = 6), 7 (MCA = 7, Sham = 6), 14 (MCA = 6, Sham = 5), and 28 (MCA = 7, Sham = 5) days after the operation. The brains were removed and divided into right and left hemisphere. Each hemisphere was homogenized and centrifuged. The supernates were filtered with membrane filter. An aliquot of the filtrate was used for measurement of xanthine and uric acid in both of the ischemic and contralateral hemisphere by a HPLC system. In the normal group, xanthine and uric acid in the brain was 12.4 +/- 0.4 and 2.2 +/- 0.1 nmol/g tissue (mean +/- SEM), respectively. In the ischemic hemisphere, xanthine increased up to 57.7 +/- 5.2 nmol/g tissue 2 hours after MCA occlusion and reached a maximum value of 59.42 +/- 4.91 nmol/g tissue 4 hours following the induction of ischemia. Xanthine level was still high 8 hours after ischemia and then rapidly decreased to the normal value at day 2.(ABSTRACT TRUNCATED AT 250 WORDS)
Correlation between serum immunosuppressive substance and clinico-pathological findings in patients with gastric carcinoma.
Serum levels of immunosuppressive substance (IS) were determined in 99 patients with gastric cancer and in 32 healthy individuals. The serum IS levels in the patients (769.6 +/- 314.8 micrograms/ml) were significantly higher than those in the healthy individuals (549.7 +/- 104.7 micrograms/ml). A multivariate analysis on the correlation between serum IS levels and clinicopathological findings in the patients disclosed that there was a close correlation between the serum IS levels and the depth of invasion, in particular, the prognostic serosal invasion, metastasis to the distal lymph nodes and peritoneal dissemination. There was, however, no correlation between the serum IS level and hepatic metastasis. Serum IS levels were higher in patients with well-differentiated adenocarcinoma than in those with poorly differentiated adenocarcinoma or signet ring cell carcinoma. A serum IS level higher than 1000 micrograms/ml indicates the possibility that the tumor is only palliatively resectable because of involvement of the distal lymph nodes or peritoneal dissemination.
Xanthine and uric acid levels in rat brain following focal ischemia.
Changes of the xanthine and uric acid (UA) levels in rat forebrain following focal cerebral ischemia were studied by reversed-phase HPLC with electrochemical detection. Focal ischemia was induced by occluding the left middle cerebral artery in the rat. The xanthine level in the normal group was 11.50 nmol/g tissue. In the ischemic group, the xanthine concentration in the ischemic hemisphere progressively increased after occlusion and reached a maximum value of 59.42 nmol/g tissue 4 h after operation. The UA level in the normal group was 2.20 nmol/g tissue, whereas in the ischemic group the UA concentration in the ischemic hemisphere gradually increased after occlusion, reaching a value of 38.53 nmol/g tissue 24 h after ischemia. The concentration of UA remained elevated in the ischemic hemisphere until 48 h after occlusion, and reached a maximum value of 38.98 nmol/g tissue. The xanthine and UA levels in the contralateral hemisphere remained unchanged. The xanthine and UA concentrations in the sham-operated group did not show a significant increase after operation. The time course of xanthine and UA levels suggests that in ischemic forebrain UA is formed from xanthine as a product of purine metabolism.
[Raman spectroscopic study of age- and cataract-related structural changes in the lens proteins of intact lenses].
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[Flow cytometry DNA analysis of a gastric cancer before and after intra-arterial anticancer chemotherapy--report of a case].
Flow cytometric DNA analysis has been performed on tumor tissue obtained by endoscopic biopsy before and after intraarterial infusion of ADM and 5Fu. The patient was a 74-year-old woman with a gastric cancer with an involvement of a para-aortic and cervical lymph nodes. Histological examination revealed a poorly differentiated adenocarcinoma, and flow cytometric DNA analysis disclosed that the DNA ploidy (DNA index) did not differ before and after intraarterial infusion of ADM and 5Fu. The fraction of the tumor cells in the S + G2.M phase of the cell cycle however, decreased from 56% to 44% with anticancer chemotherapy. A flow cytometric DNA analysis, using biopsied samples of tumor tissue, was found to be a useful tool for monitoring the effect of anti-cancer chemotherapy for solid tumors.
[HPLC-electrochemical detection method].
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Inter- and intramolecular disulfide bond formation and related structural changes in the lens proteins. A Raman spectroscopic study in vivo of lens aging.
Raman spectra have been measured for intact rat lens nuclei at various stages of aging in an attempt to gain further insight into age-related structural changes in the lens proteins, especially changes concerning protein sulfhydryl groups. Two Raman bands at 2579 and 2561 cm-1 were observed to be assignable to SH stretching modes of the cysteine residues. These bands have been attributed to "exposed" and "buried" sulfhydryl groups of the lens proteins, respectively, on the basis of a model compound study. The relative intensities of both SH stretching modes decreased with lens aging, and concurrently the intensity of a S-S stretching mode at 509 cm-1 due to disulfide bridges increased, suggesting that not only exposed but also buried protein sulfhydryl groups are converted to disulfide groups as a result of aging. The rate of the intensity decrease in the 2561 cm-1 band was similar to that in the 2579 cm-1 band. Therefore, it seems likely that the sulfhydryl groups in the two distinct environments are nearly equally subjected to the oxidation. Cysteine and cystine residues of the lens proteins gave their C-S stretching modes at 708 cm-1, indicating that they predominantly assume PC and/or PN conformers. The intensity ratio of a tyrosine doublet near 840 cm-1 (I832/I855) changed from approximately 0.86 to approximately 0.81 with the aging of the rat lens. This result implies that some tyrosine residues undergo a change in their hydrogen bonding environments during the course of aging. Of particular importance is that the relative intensity change of the tyrosine doublet with normal aging and that with cataract formation are in opposite directions.
Electrochemically treated glassy carbon electrode for amperometric detection in high-performance liquid chromatography.
The application of an electrochemically pre-treated glassy carbon electrode for the amperometric detection of electroactive components, such as tyrosine and oxipurinol, in biological samples was studied in order to demonstrate the usefulness of a pre-anodized electrode in high-performance liquid chromatography. The electrochemical pre-treatment was carried out in 0.2 M phosphate buffer (potassium dihydrogenphosphate-potassium hydroxide, pH 6.5) at 1900 mV vs. Ag/AgCl for 2 min. The pre-anodized electrode response for the oxidation of lactic acid and pyruvic acid was also studied. The electrochemical treatment enhanced and stabilized the electrode response to the oxidation of tyrosine and both acids.
Effect of aldose reductase inhibitor on experimental diabetic cataract monitored by laser Raman spectroscopy.
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Histopathological changes, mucin production and cellular DNA content in rectal mucosa of patients with ulcerative colitis: a comparison between findings in adults and adolescents.
Histopathological examination, specific mucin staining and analysis of cellular DNA content of rectal mucosa were carried out in twenty-eight tissue specimens biopsied from ten adult and eight adolescent patients with ulcerative colitis. There was an increase in proliferative activity in the rectal mucosa in both groups with active colitis, but, there were no significant differences in the potential for malignant transformation of rectal mucosa in these groups.
Effects of immunostimulation with OK432, coenzyme Q10, or levamisole on dimethylhydrazine-induced colonic carcinogenesis in rats.
Effects of immunostimulation with OK432, Coenzyme Q10 (Co-Q10), or levamisole on dimethylhydrazine (DMH)-induced colonic carcinogenesis were investigated in 45 Donryu-rats. The manipulation with one of these immunopotentiators did not prevent DMH-induced colonic carcinogenesis in these rats. However, the number of tumors was significantly reduced and the incidence of invasive carcinomas decreased by immunostimulation. The treatment also reduced the number of lesions with epithelial dysplasia within the flat colonic mucosa.
Postmortem changes in uric acid and ascorbic acid in human cerebral cortex tissues excised after cardiac death.
There has been no report on the determination of uric acid (UA) in human brain and heart tissues. UA and ascorbic acid (AA) in human cerebral cortex and heart tissues excised after cardiac death have been studied by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). It has been found that the levels of AA and UA in the human cerebral cortex tissues tend to decrease and increase, respectively, after cardiac death as a function of time between death and forensic operation. In addition, it has been found that there is no special relationship between UA levels in human heart tissues and time after cardiac death, also that the UA levels in the heart are high as compared with those in human cerebral cortex tissues. We have emphasized that the HPLC-ECD method is useful in determining UA and AA in mammalian tissues by one-time chromatography to gain a better understanding of the relationship between disease and serum urate level.
Changes of uric acid level in rat brain after focal ischemia.
Changes of uric acid level in rat cerebral hemisphere after left middle cerebral artery (MCA) occlusion were studied by reversed-phase HPLC with electrochemical detection. Uric acid level in the normal group was 2.98 nmol/g tissue. Uric acid concentration of the left hemisphere in the left MCA-occluded group progressively increased after occlusion, and reached a maximum value of 67.26 nmol/g tissue 24 h after ischemia. Uric acid levels in the right hemisphere remained unchanged. Uric acid concentration of the left hemisphere in sham-operated group was 9.29 nmol/g tissue 24 h after the operation.