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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
PubMed2000

A case of aortic dissection with transient ST-segment elevation due to functional left main coronary artery obstruction.

A 48-year-old man with a history of hypertension and diabetes mellitus was hospitalized with sudden onset of severe chest pain. He was in cardiogenic shock with a systolic pressure of 60 mm Hg. His electrocardiogram (ECG) showed ST-segment elevation in the precordial leads suggestive of acute anteroseptal myocardial infarction. The ST-segment returned to baseline after the systolic blood pressure rose to 100 mm Hg with the administration of sympathomimetic agents. Aortography and transesophageal echocardiography demonstrated type A aortic dissection and aortic regurgitation. Aortography and short-axis transesophageal echocardiography showed during diastole almost complete collapse of the true lumen of the ascending aorta caused by the intimal flap. The patient underwent surgical repair of the aortic dissection and implantation of Palmaz stents in the carotid arteries. Decreased blood pressure and the presence of aortic regurgitation accelerated the collapse of the true lumen during diastole in the ascending aorta, resulting in functional obstruction of the left main coronary artery, which may have been related to ST-segment changes in this case.

Aortic Dissection↗
PubMed2000

Effects of dietary supplementation with n-3 fatty acids compared with n-6 fatty acids on bronchial asthma.

OBJECTIVE: The effects of perilla seed oil (n-3 fatty acids) on bronchial asthma were compared with the effects of corn oil (n-6 fatty acids) in relation to the pulmonary function and the generation of leukotriene B4 (LTB4) and C4 (LTC4) by leucocytes. METHODS AND SUBJECTS: 14 asthmatic subjects were divided randomly into two groups: one group (7 subjects) consumed perilla seed oil-rich supplementation and the other group (7 subjects) consumed corn oil-rich supplementation for 4 weeks. Generation of LTs by leucocytes and respiratory function were compared between the two groups. RESULTS: The generation of LTB4 and LTC4 by leucocytes tended to increase in subjects (N=7) with corn oil-rich supplementation, and decrease in subjects (N=7) with perilla seed oil-rich supplementation. Significant differences between the two groups were observed in the generation of LTB4 at 2 weeks (p<0.05) and LTC4 at 2 weeks (p<0.05) after dietary supplementation. Significant increases in the value of PEF (p<0.05), FVC (p<0.01), FEV(1.0) (p<0.05) and V(25) (p<0.05) were found in subjects who received perilla seed oil supplementation for 4 weeks. And significant differences in the value of FVC (p<0.05) and FEV(1.0) (p<0.05) were observed between the two groups after 4 weeks of dietary supplementation. CONCLUSION: These results suggest that perilla seed oil-rich supplementation is useful for the treatment of asthma in terms of suppression of LTB4 and LTC4 generation by leucocytes, and improvement of pulmonary function.

Adult↗
PubMed1999

Bone mineral density in steroid-dependent asthma assessed by peripheral quantitative computed tomography.

Chronic use of systemic glucocorticoids results in progressive bone loss and pathologic fractures. This study identified the predictive variables for bone loss and used peripheral quantitative computed tomography (pQCT) to measure changes in cortical and trabecular bone in patients receiving systemic glucocorticoid therapy of prednisone 15.4 g. Eighty-four asthmatic patients were included in the study. Vertebral fractures were diagnosed via plain spinal radiograms. pQCT was used to measure cortical and trabecular bone mineral density. Multiple regression analysis identified variables with predictive value. The cumulative dose of glucocorticoid correlated with the bone mineral density (p<0.05) and the trabecular bone density (p<0.01). Among patients > or = 65 yrs of age, the cumulative dose of glucocorticoid correlated with the occurrence of vertebral fractures (p<0.05), total bone mineral density (p<0.01) and cortical bone mineral density (p<0.01). Bone mineral density in the distal radius measured by pQCT and the vertebral bodies by axis QCT were correlated, regardless of whether systemic glucocorticoids were administered. Glucocorticoid administration not only decreases trabecular but also cortical bone mineral density. Since cortical bone provides strength and stiffness, it appears that the loss of cortical bone is responsible for the increased incidence of fracture seen in patients receiving systemic glucocorticoid therapy.

Aged↗
PubMed1999

Interactions between cytoskeletal components during myoplasm rearrangement in ascidian eggs.

Ooplasmic segregation in ascidian eggs consists of two phases of cytoplasmic movement, the first phase is mediated by the microfilament system and the second is mediated by the microtubule system. Recently, two novel proteins, p58 and myoplasmin-C1, which are localized to the myoplasm, were suggested to have important roles in muscle differentiation. In order to analyze the molecular mechanisms underlying ooplasmic segregation, the interactions between actin, tubulin, p58 and myoplasmin-C1 were examined. During the first segregation, microtubule meshwork in the unfertilized egg disappeared. At the second segregation, a novel structure of the microtubules that extended from the sperm aster and localized in the cortical region of the myoplasm was found. Moreover, uniform distribution of the cortical actin filament was observed at the second segregation. During the course of myoplasm rearrangement, p58 and myoplasmin-C1 are colocalized and can form a molecular complex in vitro. This complex of p58 and myoplasmin-C1 is a good candidate for a cytoskeletal component of the myoplasm, and is likely to be involved in the correct distribution of cytoplasmic determinants.

Actins↗
PubMed1999

Establishment of a method for mapping of N-linked oligosaccharides and its use to analyze industrially produced recombinant erythropoietin.

A rapid and convenient method for N-linked oligosaccharide structure analysis was developed and applied to the quality examination of commercially manufactured recombinant human erythropoietin (rEPO). Oligosaccharides released from rEPO expressed in Chinese hamster ovary cells were labeled with 2-aminobenzamide, and analyzed by a combination of diethylaminoethyl (DEAE) column HPLC and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). This newly developed method allowed us to analyze sialylated oligosaccharides directly. The results showed that these oligosaccharides are composed of neutral-mono-di-tri-tetrasialyl oligosaccharides in a ratio of <1:2:13:34:51%, and that the core structure was a mixture of complex type bi-, tri- and tetra-antennary forms with one to three polylactosaminyl chains. Further analysis showed clearly that the N-linked oligosaccharide structure of rEPO has not changed throughout the past ten years of manufacturing by our company. The analysis was carried out using a small quantity (1 nmol) of rEPO, demonstrating the efficacy of the newly developed method. Further, the N-linked oligosaccharides of rEPO manufactured by our company almost coincided with those of the erythropoietin European Pharmacopoeia Biological Reference Preparation (Eur.Ph.BRP), a standard product.

Animals↗
PubMed1998

Expression of alpha-fetoprotein and albumin genes in human hepatocellular carcinomas: limitations in the application of the genes for targeting human hepatocellular carcinoma in gene therapy.

For an approach of gene therapy for hepatocellular carcinoma (HCC), transcriptional regulatory sequence (TRS) of either alpha-fetoprotein (AFP) or albumin has been used for targeting cancer cells. To examine the feasibility of using TRSs of these genes for possible gene therapy of HCCs, the cellular distribution of AFP and albumin gene transcripts was studied in 25 cases of surgically removed human HCCs. AFP gene expression was observed in HCC nodules of 13 cases. The expression in HCC was heterogeneous, and the distribution of the transcripts was mostly sparse and spotty. The higher the serum AFP levels, the larger population of the AFP-expressing HCC cells tended to reflect. In noncancerous liver, a slight AFP expression was found by Northern blot analysis, but the transcripts were not detected in the liver sections. In contrast, albumin expression was found in all HCCs as well as in noncancerous hepatocytes. In HCC, the transcripts for albumin were distributed in cancer cells, and the expression varied with nodules. There were more albumin-expressing cancer cells than the AFP-expressing cells. Albumin expression was retained even in poorly differentiated HCC, although the intensity of the signal was not as strong as in more-differentiated HCCs. Metastatic HCC nodules revealed transcripts for both AFP and albumin genes, and those were clearly recognized in the lung tissue. These results suggest that, for gene therapy for HCCs, neither AFP nor albumin are ideal options for targeting HCC cells. AFP-TRS may be used as a transcriptional regulator in selected cases in which AFP gene expression is observed in the cancer nodules. The serum AFP level appears to be an important indicator in selecting cases. Albumin-TRS in conjunction with retroviral vector might be used in limited cases such as HCCs with no AFP expression. However, careful consideration must be taken, because albumin is constitutively expressed in normal hepatocytes, and AFP-expressing nonmalignant progenitor cells possibly exist.

Adult↗
PubMed1998

Expression of E-cadherin, alpha-catenin, beta-catenin, and CD44 (standard and variant isoforms) in human cholangiocarcinoma: an immunohistochemical study.

Immunolocalization of E-cadherin (E-cad), alpha-catenin, beta-catenin, and CD44 has rarely been investigated in human cholangiocarcinoma (CC). We, therefore, immunohistochemically examined the expression of E-cad, alpha-catenin, beta-catenin, CD44 standard (CD44s), and CD44 variants (CD44v) including CD44v5, CD44v6, CD44v7-8, and CD44v10 in normal adult livers and in 47 cases of CC; and the results were then correlated with tumor grade, vascular invasion, metastasis, p53 expression, proliferative fraction (Ki-67 labeling), and c-erbB2 expression. In normal livers, E-cad, alpha-catenin and beta-catenin, but not CD44s, CD44v5, CD44v6, CD44v7-8, and CD44v10, were expressed at the cell membrane of normal intrahepatic bile ducts. In CC, membranous expression of E-cad, alpha-catenin, and beta-catenin was the same or reduced when compared with non-cancerous bile ducts in the majority of CC. We found that the down-regulation of E-cad, alpha-catenin, and beta-catenin expression significantly correlated with tumor high grade, but not with vascular invasion, metastasis, p53 expression, Ki-67 labeling, or c-erbB2 expression, except for beta-catenin, the down-regulation of which was associated with c-erbB2 down-regulation. CD44s, CD44v5, CD44v6, CD44v7-8 and CD44v10 were frequently expressed at the membrane of CC cells. There were, however, no significant correlations between these aberrant CD44 expression and tumor grade, metastasis, vascular invasion, p53 expression, Ki-67 labeling, or c-erbB2 expression, with a few exceptions of CD44s and CD44v5. We found that CD44s aberrant expression significantly correlated with absence of metastasis and vascular invasion, and that CD44v5 aberrant expression significantly correlated with p53 under-expression. These results suggest that membranous expression of E-cad, alpha-catenin, and beta-catenin is reduced in a majority of CC and this down-regulation correlates with CC high grade, and that beta-catenin down-regulation is associated with c-erbB2 down-regulation. The data also suggested that CD44s, CD44v5, CD44v6, CD44v7-8, and CD44v10 may be neoexpressed during carcinogenesis of CC but this neoexpression does not correlate with tumor progression in CC, with the exception of CD44s and CD44v5.

Adult↗
PubMed1998

Effective TAE therapy using Lipiodol with epirubicin for liver metastases of nonfunctioning islet cell carcinoma of the pancreas.

We report the response of two patients with advanced nonfunctioning islet cell carcinoma of the pancreas with liver metastases treated with a combination of surgi-cal resection and transarterial embolization (TAE), using Lipiodol with epirubicin. After pretreatment evaluation, the two patients were diagnosed with nonfunctioning islet cell carcinoma of the pancreas with liver metastases. Preoperatively, in both patients, TAE was performed through the hepatic arteries, using Lipiodol and sponzel plus epirubicin. Surgical resection of the primary tumor (radical distal pancreatectomy and pancreaticoduodenectomy) was performed. After surgical resection and evaluation of the malignant histopathological features of the neoplasms, chemotherapy, which included oral 5-fluorouracil (FU), and transarterial infusion therapy, using Lipiodol with epirubicin, was administered to the patients. Follow-up evaluation of the two patients by computerized tomography (CT) scan showed a reduction in the size of the metastatic hepatic masses after several chemoembolizations through the hepatic arteries. This combined treatment modality may be an effective therapeutic strategy for improved management of patients with advanced nonfunctioning islet cell carcinoma of the pancreas with liver metastases.

Adult↗
PubMed1998

Expression of epithelial-cadherin, alpha-catenin and beta-catenin during human intrahepatic bile duct development: a possible role in bile duct morphogenesis.

BACKGROUND/AIMS: Cell adhesion molecules play an important role in the morphogenesis of developing organs. However, little is known about their expression during intrahepatic bile duct development. METHODS: We immunohistochemically investigated the expression of E-cadherin (E-Cad), alpha-catenin (A-Cat) and beta-catenin (B-Cat) during human intrahepatic bile duct development, using 31 fetal livers of various gestational ages. The developmental stages of bile ducts were classified into the ductal plate, migrating biliary cells (remodeling stage), and immature bile ducts (remodeled stage). RESULTS: E-Cad was broadly and strongly expressed in the ductal plate with a cytoplasmic pattern, heterogeneously and weakly expressed in the migrating biliary cells with a cytoplasmic pattern, and broadly and strongly expressed in immature bile ducts with a membranous pattern. A-Cat was broadly and strongly expressed in the ductal plate with a membrane pattern, broadly and moderately expressed in the migrating biliary cells with a membranous pattern, and broadly and strongly expressed in immature bile ducts with a membranous pattern. In contrast, expression of B-Cat was weak or slight in the ductal plate, but B-Cat was expressed broadly and strongly with a membranous pattern in migrating biliary cells and in immature bile ducts. Immature hepatocytes rarely expressed E-Cad and A-Cat, but expressed B-Cat with a membranous pattern throughout development. CONCLUSIONS: These results suggest that E-Cad, A-Cat and B-Cat are involved in the normal developmental morphogenesis of human intrahepatic bile ducts.

Bile Ducts, Intrahepatic↗
PubMed1998

The role of endogenous acid in the development of acute gastric ulcer induced by ischemia-reperfusion in the rat.

We investigated the role of endogenous gastric acid in the development of gastric ulcer from erosion induced by ischemia-reperfusion of the celiac artery in the rat. A half-hour clamping of the celiac artery (ischemia) caused acute gastric erosions 1 hour after reperfusion and such acute injuries progressed to ulcers 48-72 hours after reperfusion without any necrotizing agents. Gastric acid secretion decreased immediately after ischemia and didn't recover until 12 hours after reperfusion. Intraperitoneal administrations of cimetidine (100 mg/kg, every 12 hours) or omeprazole (30 mg/kg, every 24 hours) were started at 1, 6, or 12 hours after reperfusion. When administrations were started 1 hour after reperfusion, both drugs significantly decreased the total damaged area and prevented the progression of gastric erosions to ulcers. However, administrations started 6 or 12 hours after reperfusion failed to inhibit the total damaged area and to prevent ulcer formation. These results suggest that endogenous gastric acid may play an important role in the progression of gastric erosions to ulcers although ischemia itself reduces acid secretion. Furthermore, treatment with anti-acid-secretory drugs in the early stage of mucosal damage may be important for the prevention of ulcer.

Acute Disease↗
PubMed1998

c-erbB-2 protein is expressed in hepatolithiasis and cholangiocarcinoma.

AIMS: The c-erbB-2 proto-oncogene encodes a transmembrane protein which is highly homologous to epidermal growth factor receptor. Overexpression of this c-erbB-2 protein has been reported in many human carcinomas, including breast carcinoma. However, there have been few studies of the expression of c-erbB-2 in cholangiocarcinoma and hepatolithiasis, a condition occasionally associated with cholangiocarcinoma. METHODS AND RESULTS: In this study, we evaluated immunoreactivity for the c-erbB-2 protein in human cholangiocarcinomas (n = 47), hepatolithiasis (n = 20), fetal livers (n = 36) and normal adult livers (n = 6). In normal adult livers and fetal livers, expression of c-erbB-2 protein could not be detected in hepatocytes or intrahepatic biliary cells. In hepatolithiasis, there was overexpression of c-erbB-2 in 15/20 (75%). The expression was found with a membranous pattern on the proliferated intrahepatic bile ducts and proliferated intrahepatic peribiliary glands around the bile ducts containing stones. Hepatocytes were negative for c-erbB-2 protein. Moreover, the biliary cell expression of the c-erbB-2 protein correlated significantly with Ki67 labelling index. On the other hand, aberrant expression of c-erbB-2 was found in 33/47 (70%) cholangiocarcinomas. The c-erbB-2 expression in cholangiocarcinomas did not correlate with Ki67 labelling index or p53 expression. CONCLUSIONS: These results indicate that aberrant expression of c-erbB-2 protein is found in cholangiocarcinoma and also in noncancerous biliary proliferative lesions such as hepatolithiasis. These findings also suggest that c-erbB-2 oncogene participates not only in cholangiocarcinogenesis but also in biliary cell proliferation in non-neoplastic conditions.

Adult↗
PubMed1998

Endoscopic retrograde cholangiopancreatography in paediatric patients with biliary disorders.

Endoscopic retrograde cholangiopancreatography (ERCP) has long been used in children. The usefulness of ERCP in paediatric patients with various biliary disorders, however, has not been well documented. Thirty-two sessions of ERCP performed in 29 paediatric patients ranging in age from 1 month to 15 years were evaluated. Endoscopic retrograde cholangiopancreatography was to confirm diagnosis or to obtain detailed information about their pancreaticobiliary system. Cannulation was successful in all patients. Opacification of the biliary tracts was also successful in all except for three patients with extrahepatic biliary atresia. Endoscopic retrograde cholangiopancreatography was assessed to be successful in making a differential diagnosis of neonatal hepatitis from extrahepatic biliary atresia, and in having a confirmed diagnosis of anomalous arrangement of the pancreaticobiliary ductal system associated with choledochal cyst. The procedure was also useful for obtaining detailed information on the pancreaticobiliary system in the other children. No accidents occurred during the endoscopic procedures in any of the paediatric patients. When a confirmed diagnosis or detailed information is needed in paediatric patients with biliary disorders, ERCP is a useful and safe technique.

Adolescent↗
PubMed1998

Direct measurement of nitric oxide release in gastric mucosa during ischemia-reperfusion in rats.

Nitric oxide (NO) generation in the rat gastric mucosa during ischemia-reperfusion was measured using an NO-sensitive electrode. Under pentobarbital sodium anesthesia, an electrode was inserted into the submucosa from the serous membrane side in the fundus. After steady-state baseline recording, the celiac artery was clamped for 30 min, and then ischemia-reperfusion was achieved by removing the clamp. The clamping of the celiac artery caused a decrease in blood flow and an increase in NO level in the gastric tissue. Just after the removal of the clamp, the NO level rapidly fell and returned to the baseline level. Administration of NG-nitro-L-arginine methyl ester (an NO synthase inhibitor, 30 mg/kg i.p.) before ischemia significantly attenuated both the increase in NO level during ischemia and the formation of acute gastric mucosal lesions observed after 60 min reperfusion. Administration of superoxide dismutase (a superoxide radical scavenger, 10,000 U/kg i.v.) at the end of ischemia inhibited both the rapid decrease in NO level during the reperfusion and the gastric mucosal erosions. Because NO and superoxide radical produce a highly reactive peroxynitrite, it can be argued that NO has an important pathological role in acute gastric mucosal injury induced by ischemia-reperfusion. Our conclusion was strongly supported by immunohistochemical staining of nitrotyrosine residues, an indication of peroxynitrite formation.

Animals↗
PubMed1998

Direct vasoconstrictor action of homologous angiotensin II on isolated arterial ring preparations in an elasmobranch fish.

Arterial rings were prepared from the branchial artery, coeliac artery and ventral aorta of the Japanese dogfish Triakis scyllia and used to determine arterial contraction in a myograph. Noradrenaline caused a dose-dependent contraction (10(-9)-3 x 10(-6) M) that was completely inhibited by pre-treatment with 10(-7) M phentolamine. Homologous dogfish angiotensin II (ANG II) ([Asn1, Pro3, Ile5]-ANG II) also caused dose-dependent contraction (10(-9)-3 x 10(-6) M), but phentolamine had no effect on this response. Administration of dogfish angiotensin I (ANG-I) ([Asn1, Pro3, Ile5, Gln9]-ANG I) resulted in a contraction similar to that produced by ANG II and the effect could be blocked with 10(-7) M captopril. The mammalian ANG II receptor antagonists [Sar1, Ile8]-ANG II and [Sar1, Ala8]-ANG II caused dose-dependent contractions of coeliac artery rings, but were less potent than homologous ANG I and ANG II. These results show that the contractile effect of [Asn1, Pro3, Ile5]-ANG II is not mediated by the alpha-adrenergic system and contractions of arterial rings by noradrenaline and elasmobranch ANG II are mediated by separate vascular receptors. The elasmobranch ANG II vascular receptor may have co-evolved with the unusual structure of this peptide.

Adrenergic alpha-Antagonists↗
PubMed1998

Rhabdomyolysis after infection and taking a cold medicine in a patient who was susceptible to malignant hyperthermia.

A case of rhabdomyolysis after a possible viral infection and the use of a cold medication is reported. A 41-year-old man who presented with dysarthria, dysphagia, progressive weakness of his muscles and a high grade fever was admitted. He suffered from massive rhabdomyolysis, acute renal failure, and bronchopneumonia. Hemodialysis, antibiotics, and hydration therapy were effective in the treatment of his illness. Although the cause of the rhabdomyolysis was not completely clear, he was subsequently shown to be susceptible to malignant hyperthermia (MH) based on the results of a caffeine-halothane contracture test. When a mild recurrence occurred during a follow-up muscle biopsy, intravenous dantrolene sodium was administered and he improved immediately. This case suggests that MH should be considered in patients with rhabdomyolysis when the cause is unclear. The caffeine-halothane contracture test may also be helpful in the diagnosis.

Adult↗
PubMed1998

Disturbance of consciousness associated with hypophosphatemia in a chronically alcoholic patient.

A 69-year-old man with chronic alcoholism was admitted to our hospital due to disturbance of consciousness and oliguria. Emergency laboratory examination revealed metabolic acidosis, hypoglycemia, hyponatremia, mild liver dysfunction, acute renal failure and rhabdomyolysis. After administration of fluids and nutrients and continuous hemodiafiltration, he recovered from all signs and symptoms except for disturbance of consciousness after 7 days. Since severe hypophosphatemia persisted, we administered adequate phosphates, and then his level of consciousness normalized. We discuss the relationships among alcohol abuse, hypophosphatemia and disturbance of consciousness, and recommend that hypophosphatemia be considered a potential cause of disturbance of consciousness in alcoholic patients.

Acidosis↗
PubMed1998

Different roles of histamine and leukotriene C4 in the airways between patients with atopic and nonatopic asthma.

The release of histamine and leukotriene C4 (LTC4) from bronchoalveolar lavage (BAL) cells and peripheral blood stimulated with Ca ionophore A23187 was compared between atopic and nonatopic asthma. The proportion of basophilic cells in BAL fluid was significantly higher in atopic than in nonatopic asthma (p < 0.01); however, no significant differences were present in the other BAL cells between the two asthma types. The concentration of histamine in BAL fluid was significantly higher in younger patients (20-59 years) with atopic than in nonatopic asthma (p < 0.01). In contrast, the concentration of LTC4 was significantly higher in nonatopic than in younger patients with atopic asthma (p < 0.01). The release of histamine from BAL cells (p < 0.001) and peripheral blood (p < 0.01) was significantly larger in younger patients with atopic than in nonatopic asthma. The generation of LTC4 by BAL cells was significantly larger in nonatopic than in younger (p < 0.01) and older patients with atopic asthma (60+ years) (p < 0.05). These results suggest that both histamine and LTC4 participate in the onset mechanism of atopic asthma, and only LTC4 participates in that of nonatopic asthma.

Adult↗