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Biomedical subjects

K Ashida

Publications and source records attributed to K Ashida.

At least 37 records · Page 2Linked to original sources
PubMed1997

Endocrine cells in intraductal papillary-mucinous neoplasms of the pancreas. A histochemical and immunohistochemical study.

The endocrine cells in intraductal papillary-mucinous neoplasms (IPN) of the pancreas have rarely been investigated. In the normal pancreatic ducts of normal pancreases (n = 5) there were a few endocrine cells: argyrophil in 5 (100%), chromogranin A in (100%), pancreatic polypeptide (PP) in 3 (60%), and insulin in 7 (20%). These endocrine cells were scattered, and located in the basal portions of pancreatic ducts. In IPN of the pancreas (n = 9), there were many endocrine cells: argyrophil in 7 (78%), argentaffin in 8 (89%), chromogranin A in 8 (89%), PP in 7 (78%), serotonin in 7 (78%), insulin in 4 (44%), and gastrin in 5 (56%). In invasive ductal adenocarcinoma of the pancreas (n = 6), many endocrine cells were also detected: argyrophil cells in (67%), chromogranin A in 3 (50%), insulin in 3 (50%), glucagon in 4 (67%), and somatostatin in 3 (50%). In positive cases, endocrine cells were situated under or among the neoplastic cells and the proportion of endocrine cells in IPN was less than 5% of the total neoplastic cell population. These data show that normal pancreatic ducts contain endocrine cells and that IPN frequently contain argyrophil, argentaffin, chromogranin A, and hormone-containing endocrine cells. These data also suggest that endocrine differentiation occurs during neoplastic transformation and progression of IPN of the pancreas.

Adenocarcinoma, Mucinous↗
PubMed1997

Expression of pancreatic digestive enzymes in normal and pathologic epithelial cells of the human gastrointestinal system.

Pancreatic digestive enzymes have rarely been reported in human nonpancreatic organs. We examined their expression in the epithelial cells of the nonpancreatic gastrointestinal organs, looking for pancreatic alpha-amylase, trypsin, chymotrypsin and pancreatic lipase. Western blotting, enzyme assay and pancreatic alpha-amylase mRNA were also used in selected specimens. In normal tissues, immunoreactivity of one or more of these enzymes was frequently noted in cells of the salivary glands, stomach, duodenum, large pancreatic ducts, extrahepatic bile ducts and gall bladder. The epithelium of the normal oesophagus, small intestine and colon were consistently negative for these enzymes. In pathologic tissues, immunoreactivity for one or more enzymes was present in epithelial cells of pleomorphic adenomas of the salivary glands, oesophageal squamous cell carcinoma, gastric adenoma and adenocarcinoma, pancreatic adenocarcinoma, cholecystitis, adenocarcinoma of the gall bladder and extrahepatic bile duct, and colon adenoma and adenocarcinoma. Western blotting showed a specific band of each enzyme in some specimens of normal stomach. In situ hybridization for pancreatic alpha-amylase mRNA showed specific signals in the normal stomach, but not in the normal colon. Reverse transcriptase polymerase chain reaction analysis for pancreatic alpha-amylase mRNA revealed specific signals in the normal stomach. Enzyme assay revealed that the stomach and gall bladder showed these activities. The data suggest that pancreatic digestive enzymes are produced by several epithelial cell types of the nonpancreatic gastrointestinal organs, that the organs positive for pancreatic enzyme have a common cell lineage, and that neoplasms continue to express or neoexpress these enzymes after neoplastic transformation.

Adult↗
PubMed1997

Quantitative analysis of cyclooxygenase-2 gene expression on acute gastric injury induced by ischemia-reperfusion in rats.

The rat model of acute gastric damage induced by ischemia-reperfusion (I-R) has been used to evaluate the protective effect of various drugs on gastric injury. However, the quantitative expression state of cyclooxygenase-2 (COX-2), a protein which induces cytoprotective prostaglandins during inflammation, is still unknown in acute gastric injury induced by I-R. Therefore, we have quantitatively investigated the level of expression of COX-2 mRNA in injured gastric tissue of this model using the reverse transcription-competitive polymerase chain reaction method. The mRNA for COX-2 was expressed at low or undetectable levels in the normal gastric tissues in control rats, which were fasted for 18 hrs without I-R. The mRNA levels of COX-2 in injured gastric tissues were higher than those of control tissues between 6 hrs and 48 hrs after I-R. The maximum expression of COX-2 mRNA was recorded at 24 hrs (approximately a 200-fold increase). The expression state of COX-2, which has been ascertained in this study, should be useful in evaluating the effect of various drugs on the expression of COX-2 in acute gastric damage.

Actins↗
PubMed1997

Inhibition by cigarette smoke of lipid peroxidation-induced neurotransmitter release.

Effects of water-soluble substance in cigarette smoke on neurotransmitter release were investigated using nerve terminals (synaptosomes) prepared from rat cerebral cortex. 2,2'-Azobis (2-amidinopropane) dihydrochloride (ABAP), a peroxyl radical-generator, enhanced the depolarization-evoked release of glutamate and aspartate from synaptosomes with concomitant increase in thiobarbituric acid-reactive substances (TBA-RS) levels in membrane lipids of synaptosomes. The trapped smoke-substance attenuated the lipid peroxidation-enhanced release of excitatory amino acids during the depolarization with reduction in TBA-RS, although it failed to affect the basal release of neurotransmitters. These data suggest that cigarette smoke may possess antioxidant properties to reduce oxidation-induced enhancement of transmitter release from nerve terminals.

Amidines↗
PubMed1997

Substances in the aqueous fraction of cigarette smoke inhibit lipid peroxidation in synaptosomes of rat cerebral cortex.

The effects of water-soluble substances in cigarette smoke on lipid peroxidation were investigated using nerve terminals prepared from the rat cerebral cortex. The prepared smoke-substances significantly reduced the spontaneous increase in thiobarbituric acid-reactive substances in synaptosomes in a dilution factor-dependent manner. Furthermore, the aqueous extract also inhibited the elevation of lipid peroxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride, a peroxyl radical generator. Smoke-substances scavenged superoxide radicals generated from stimulated human leukocytes and from the xanthine/xanthine oxidase system. These effects were not mimicked by nicotine. The antioxidant effects of smoke-substances were preserved for several days at 5 degrees or -80 degrees C. The results suggest that the smoke-substances may possess long half-lives and scavenge the radicals which cause lipid-peroxidation in synaptosome membranes.

Animals↗
PubMed1997

Effect of plaunotol on gastric injury induced by ischaemia-reperfusion in rats.

Plaunatol, an anti-ulcer drug, increases prostaglandin content in gastric tissue but its effect on radical-mediated gastric damage or activity against reactive oxygen species is unknown. We examined the effects of oral administration of plaunotol (Kelnac) on the acute gastric mucosal lesion and its progression to ulcer lesion induced by ischaemia-reperfusion in rats. Plaunotol (30 and 100 mg kg-1, 15 min before ischaemia) significantly reduced the total erosion area observed immediately after ischaemia-reperfusion. When plaunotol (30 and 100 mg kg-1, once a day) was administrated orally 60 min after reperfusion, it prevented the progression from erosion to ulcer. At 72 h after ischaemia-reperfusion, the total area of ulcers lesions was significantly reduced compared with that without plaunotol administration. Furthermore, treatment with plaunotol (100 mg kg-1) significantly increased prostaglandin E2 content in gastric tissues of both acute gastric mucosal lesion and gastric ulcer lesion. In in-vitro experiments, plaunotol (1-3 mg mL-1) reduced the superoxide radicals generated by leucocytes, but not by xanthine oxidase. These results indicate that plaunotol has protective effects on both the onset of acute gastric mucosal injury and its progression to ulcer lesion induced by ischaemia-reperfusion. Both effects of plaunotol on increase in prostaglandin content in gastric tissues and inhibition of superoxide radical from leucocytes may play important roles on the protection against gastric mucosal injury.

Animals↗
PubMed1997

High signal intensity on T2-weighted magnetic resonance imaging and cerebral hemodynamic reserve in carotid occlusive disease.

BACKGROUND AND PURPOSE: The importance of MR imaging in carotid artery disease is unclear. We evaluated the sensitivity and specificity of the high signal intensity changes on MR images for diagnosis of hemodynamically compromised unilateral internal carotid artery disease. METHODS: We evaluated the association of high signal intensities on T2-weighted MR images with changes in cerebral perfusion reserve measured using 99mTc-hexamethylpropyleneamine oxime single-photon emission CT and acetazolamide in 23 patients. RESULTS: Eleven patients had a type I response (normal flow and normal perfusion reserve), 8 patients had a type II response (normal flow and decreased perfusion reserve), and 4 patients had a type III response (decreased flow and decreased perfusion reserve). High signal intensities in the centrum semiovale (11/12) and/or posterior periventricular white matter (6/12) were frequently seen in the hemodynamically compromised groups. Extensive high signal intensities were associated with severely impaired cerebral circulation. MR imaging had high sensitivity (0.92) and specificity (1.0) in predicting hemodynamically compromised patients when we used the presence of T2 high intensity in the centrum semiovale as a criterion. CONCLUSIONS: The centrum semiovale T2 hyperintensities lateralized to the side of carotid occlusion are specific and sensitive for the presence and severity of hemodynamic compromise from carotid occlusive disease.

Acetazolamide↗
PubMed1997

[Psychological investigation on spa therapy in patients with bronchial asthma].

To evaluate the effects of complex spa therapy (swimming training in a hot spring pool + fango therapy + inhalation of iodine salt solution) on psychological factors, three psychological examinations; CMI (Cornell Medical Index), SDS (Self-Rating Depression Scale) and CAI (Comprehensive Asthma Inventory); were given 25 patients with bronchial asthma (10 male, 15 female, mean age 60 years), and the results of these examinations were compared before and after spa therapy. 1. Physical symptoms, respiratory system and CIJ symptoms by CMI were significantly improved after spa therapy, however the improvement of psychical symptoms was not significant. 2. In SDS, 11 of 25 patients showed more than 40 points, indicating depressive state. The number of such patients decreased from 11 to 2 and the mean SDS score significantly improved from 38.7 to 34.2 after spa therapy. 3. Conditioning, suggestion, fear of expectation, frustration, flight into illness, negative attitudes towards prognosis, and decreased motivation towards therapy by CAI were significantly reduced after spa therapy, with the reduction in negative attitudes towards prognosis and decreased motivation towards therapy being relatively large. Furthermore, CAI score, which is the average of the categories in CAI, was also significantly decreased from 37.9 to 28.4 after spa therapy. These results suggested that complex spa therapy improves psychological factors in patients with bronchial asthma.

Aged↗
PubMed1996

Telomerase as a tool for the differential diagnosis of human hepatocellular carcinoma.

BACKGROUND: Telomerase activation is thought to be essential for the immortality of cancer cells. We measured telomerase activity in human liver samples, including hepatocellular carcinoma (HCC), and evaluated this assay as a tool for the diagnosis of HCC using 21-gauge (21-G)-needle biopsy specimens. METHODS: Ninety-four liver samples (27 HCC, 27 liver cirrhosis, 37 chronic hepatitis, and 3 normal liver) that were surgically resected or biopsied with a 12-gauge Silverman needle and 13 HCC samples that were biopsied with a 21-G needle were analyzed for telomerase activation. RESULTS: Eleven of 29 (38%) tumor-bearing liver samples were weakly telomerase-positive, whereas telomerase activity was observed infrequently in nontumor-bearing liver samples (6 of 35; 17%) and in normal liver samples (0 of 3; 0%). The positivity of surgical samples for well differentiated, moderately differentiated, and poorly differentiated HCC was 88% (7 of 8), 87% (13 of 15), and 0% (0 of 2), respectively. In telomerase-positive HCC, 43% (3 of 7) of well differentiated samples were weakly positive, whereas 92% (12 of 13) of moderately differentiated samples were strongly positive. The difference in the tumor sizes and viral marker status did not affect the activity. The telomerase activity of the 21-G-needle biopsied specimens showed no significant difference from that of the surgical samples. The positive incidence of 21-G specimens was 80% (8 of 10) and 100% (2 of 2) in well differentiated HCC and moderately differentiated HCC, respectively. CONCLUSIONS: An incremental positivity of telomerase was observed during hepatocarcinogenesis. The use of this assay in 21-G-needle biopsy specimens may be useful in clinical examination.

Adolescent↗
PubMed1996

Changes of thyrotropin-releasing hormone concentration in the brain and levels of prolactin and thyroxin in the serum during spawning migration of the chum salmon Oncorhynchus keta.

Changes in concentration of thyrotropin-releasing hormone (TRH) in various regions of the brain of female and male chum salmon Oncorhynchus keta during their spawning migration toward the home stream were examined to determine the physiological role of TRH. In the same specimens, serum levels of prolactin (PRL) and thyroxin (T4) were also examined and compared with the change of TRH concentration. TRH concentration in the olfactory bulb of males increased significantly just before the upstream migration or entering the river and dropped after entering the home stream. TRH concentration in the olfactory lobe was also slightly higher in Class 2 salmons with nuptial coloration captured in coastal water than in the other groups. TRH concentrations in hypothalamus and pituitary remained relatively low during the spawning migration. The change of TRH concentration in females was similar to that in males, but was smaller and with a wider range. The serum level of PRL was extremely low in both males and females collected in coastal waters (Classes 1 and 2) and increased after the fish entered the river. The serum level of T4 in both males and females tended to be low, as did the TRH concentration in the hypothalamus and pituitary. Immunohistochemistry of the brain using anti-proTRH serum revealed many proTRH cell bodies in the olfactory bulb and olfactory lobe. These results indicate that TRH in the homing salmon is produced mainly in the olfactory bulb and lobe and that its production may be related to changes in olfactory function during migration.

Amino Acid Sequence↗
PubMed1996

Cellular distribution of transcripts for tissue inhibitor of metalloproteinases 1 and 2 in human hepatocellular carcinomas.

The cellular distribution of tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 was studied by using in situ hybridization in surgically removed human hepatocellular carcinomas (HCCs) and cholangiocellular carcinomas (CCCs). The purpose of this study was to characterize the protein involvement of TIMPs in the development of HCCs and CCCs. All HCCs and CCCs expressed TIMPs. The distribution of transcripts for TIMPs in the tumors was mostly homogeneous. Expression of TIMP in cancer cells was more intense than that in the surrounding noncancerous liver (either, cirrhosis, chronic hepatitis, or normal), and expression of TIMP-1 was stronger than that of TIMP-2. Expression of TIMPs varied among HCC nodules, but there was no obvious association between the expression level of TIMPs and differentiation stages or invasiveness of the HCCs. Transcripts for TIMPs were clearly demonstrated in the metastatic HCC nodules in the lung. Expression of TIMP-1 CCC was strong, and small nodules of CCC were recognized in the liver. Immunohistochemical study for TIMP-1 revealed a consistent staining of the TIMP protein with the transcripts. In the peritumoral histologically normal liver, which was not infected with either hepatitis B or C virus, expression of TIMP-1 was found in various cell types, but that of TIMP-2 was weak. Expression of TIMP-1 in hepatocytes revealed clear zonal distribution. These results suggest that TIMPs may act on modulating the matrix/tumor interaction and may play an important role in growth and invasion of HCCs and CCCs. Expression of TIMP-1 can be a marker of HCC metastasis to the lung, and also that of the extent of CCC invasion. Furthermore, the consistent expression of TIMPs in many cell types of the noncancerous liver suggests some unknown functional role that must be clarified.

Aged↗
PubMed1996

Telomere length in human liver diseases.

To determine the role of telomere-mediated gene stability in hepatocarcinogenesis, we examined the telomere length of human liver with or without chronic liver diseases and hepatocellular carcinomas (HCC). The mean telomere restriction fragment (TRF) length of normal liver (n = 13), chronic hepatitis (n = 11), liver cirrhosis (n = 24) and HCC (n = 24) was 7.8 +/- 0.2, 7.1 +/- 0.3, 6.4 +/- 0.2 and 5.2 +/- 0.2 kb, respectively (mean +/- standard error). TRF length decreased with a progression of chronic liver diseases and that in HCC was significantly shorter than that in other chronic liver diseases (p < 0.05). The ratios of TRF length of HCC to that of corresponding surrounding liver of well differentiated (n = 7), moderately differentiated (n = 10) and poorly differentiated (n = 4) HCCs were 0.83 +/- 0.06, 0.75 +/- 0.05 and 0.98 +/- 0.09, respectively. The ratio of poorly differentiated HCC was significantly higher than that of moderately differentiated HCC (p < 0.05). A comparison between the size and telomere length ratio of moderately differentiated HCCs revealed a decrease of the ratio with size until it reached 50 mm in diameter. In contrast, the ratio increased as the size enlarged over 50 mm. These findings suggest that the gene stability of the liver cells mediated by the telomere is reduced as chronic liver disease progresses and that telomerase is activated in poorly differentiated HCC and moderately differentiated HCC over 50 mm in diameter.

Adolescent↗
PubMed1996

Diurnal variation in intragastric pH in children with and without peptic ulcers.

Diurnal variation in intragastric pH in children with peptic ulcers has not been previously reported. Therefore, we monitored intragastric pH during a 24-h period in 82 subjects (10 children with gastric ulcers, 9 children with duodenal ulcers, 58 non-ulcer (comparison group) children, and 5 healthy adults) using a monopolar glass pH electrode. The percent of readings below pH 2, 3, 4, and 5 for each subject was calculated and compared between the comparison group and the two ulcer groups using means and slopes (i.e. changes in percent with age for each group) of percent readings for each pH analysis. In the comparison group children, gastric acidity increased with age and reached adult levels by 14 y. Mean readings for all pH analyses in gastric ulcer children were lower than those in age-adjusted comparison children (p < 0.05). The slopes of the relationships between age and the percent time below any pH for the gastric ulcer group were different from those in the comparison group (p < 0.05) and were negative for all pH analyses. The mean time below pH 2 in children with duodenal ulcers was greater than that in age-adjusted comparison children (p = 0.002). The slope of the relationship between age and the percent time below pH 2 in the duodenal ulcer group was different from that in the comparison group (p < 0.05). Gastric acidity in children with primary gastric ulcers was reduced during childhood, but in children with primary duodenal ulcer, gastric acidity was at or above adult levels.

Adolescent↗
PubMed1996

Characterization of non-pigmented Staphylococcus chromogenes.

A large number of non-pigmented Staphylococcus chromogenes were isolated from the skin of piglets with exudative epidermitis and healthy pigs. Their characteristics were homologous with S. chromogenes type strain, except for pigment production. Strains of non-pigmented S. chromogenes exhibited high levels of DNA homology with S. chromogenes type strain. The colony morphology and pigmentation of non-pigmented S. chromogenes was very similar to S. hyicus type strain, but their characteristics differ in hyaluronidase production, heat stable DNase, Tween 80 hydrolysis and bacitracin resistance. Further, DNA homology drew a distinction between non-pigmented S. chromogenes and S. hyicus type strain.

Animals↗
PubMed1996

Changes of Thyrotropin-Releasing Hormone Concentration in the Brain and Levels of Prolactin and Thyroxin in the Serum during Spawning Migration of the Chum Salmon Oncorhynchus keta

Changes in concentration of thyrotropin-releasing hormone (TRH) in various regions of the brain of female and male chum salmon Oncorhynchus keta during their spawning migration toward the home stream were examined to determine the physiological role of TRH. In the same specimens, serum levels of prolactin (PRL) and thyroxin (T4) were also examined and compared with the change of TRH concentration. TRH concentration in the olfactory bulb of males increased significantly just before the upstream migration or entering the river and dropped after entering the home stream. TRH concentration in the olfactory lobe was also slightly higher in Class 2 salmons with nuptial coloration captured in coastal water than in the other groups. TRH concentrations in hypothalamus and pituitary remained relatively low during the spawning migration. The change of TRH concentration in females was similar to that in males, but was smaller and with a wider range. The serum level of PRL was extremely low in both males and females collected in coastal waters (Classes 1 and 2) and increased after the fish entered the river. The serum level of T4 in both males and females tended to be low, as did the TRH concentration in the hypothalamus and pituitary. Immunohistochemistry of the brain using anti-proTRH serum revealed many proTRH cell bodies in the olfactory bulb and olfactory lobe. These results indicate that TRH in the homing salmon is produced mainly in the olfactory bulb and lobe and that its production may be related to changes in olfactory function during migration.

Journal Article↗