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Biomedical subjects

S Ueda

Publications and source records attributed to S Ueda.

At least 703 records · Page 39Linked to original sources

[Role of active oxygen species and lipid peroxidation in liver injury induced by ischemia-reperfusion].

The role of superoxide and lipid peroxidation in liver injury induced by ischemia-reperfusion was investigated in rats. Ischemic condition of the liver was created by applying small clamps to the right branch of portal vein and the right hepatic artery for 15 min. Clamping of hepatic artery and portal vein could decrease the hepatic blood flow to about 30% of that measured before the clamping. Levels of serum GPT and thiobarbituric acid (TBA) reactive substances in the liver tissue were significantly increased 30 min after the reperfusion following 15 min of ischemia. The increase in serum GPT and TBA reactants in the liver tissue was significantly inhibited by the treatment with superoxide dismutase combined with catalase. The treatment with allopurinol significantly inhibited the elevation of serum GPT levels and showed a tendency to inhibit the increase in TBA reactants in liver tissue. These results suggest that active oxygen species and lipid peroxidation may play an important role in the pathogenesis of ischemia-reperfusion injury in the liver, and hypoxanthine-xanthine oxidase system may be one of the main sources of active oxygen species.

Animals↗

[Role of free radicals and lipid peroxidation in gastric mucosal injury induced by ischemia-reperfusion in rats].

Ischemia and reperfusion is of the greatest importance in the pathology of various diseases. This study was designed to investigate the role of oxygen-derived free radicals and lipid peroxidation in gastric mucosal injury induced by ischemia-reperfusion in rats. Clamping of the celiac artery in rats reduced the gastric mucosal blood flow to 10% of that measured before the clamping. Gastric mucosal injury, such as spotty and linear hemorrhagic erosions, was seen in rats 60 min of the reperfusion following 30 min of ischemia. Thiobarbituric acid (TBA) reactants in the gastric mucosa were increased after the reperfusion. The increase in gastric mucosal lesions and TBA reactants were significantly inhibited by the treatment with SOD+ catalase and allopurinol. These results suggest that oxygen-derived free radicals and lipid peroxidation may play an important role in the pathogenesis of acute gastric mucosal lesions induced by ischemia-reperfusion.

Animals↗

[CT findings in bilateral adrenal enlargement].

CT findings in ten patients with bilateral adrenal enlargement (six cases of adrenal metastasis, two cases of malignant lymphoma, one case of pheochromocytoma and one case of adrenal hemorrhage) reviewed. Four of six cases of adrenal metastasis showed asymmetrical adrenal enlargement on initial CT scans. Ring enhancement on postcontrast CT was recognized in one case of adrenal metastasis and one case of adrenal hemorrhage (subacute stage). Ring enhancement in the case of adrenal hemorrhage was more clear and smooth than that in the case of adrenal metastasis. One case of malignant lymphoma and one case of adrenal hemorrhage had Addison's disease.

Adrenal Gland Diseases↗

[Effects of FUT-175 on mouse model of acute hepatic necrosis induced by endotoxin following immunological procedure].

Acute hepatic necrosis was induced by a single i.v. injection of lipopolysaccharide (LPS) into C57BL/6 mice following immunization with syngeneic liver protein and adjuvant. Sixty percent of the mice died of massive hepatocyte necrosis within 48 hours of LPS injection. The serum lactate dehydrogenase and aspartate aminotransferase levels were markedly elevated. The fatal and hepatotoxic action of LPS was prevented by pretreatment with FUT-175 (1.6 mg/kg), a synthetic protease-inhibitor. The inhibitory effects of FUT-175 was not demonstrated when the agent was given to the mice 2 h after the administration of LPS. These results seem to indicate that the hepatotoxic effects of LPS are mediated by endogenous host mechanisms in which proteases play an important role.

Adjuvants, Immunologic↗

[A case of a basilar bifurcation aneurysm associated with common carotid artery occlusion].

A case of a basilar bifurcation aneurysm associated with common carotid artery occlusion is reported. A 40-year-old woman was admitted to our hospital with severe headache and nausea. On admission, no neurological abnormality was observed. CT scan showed thin subarachnoid hemorrhage in the basal cistern. Left vertebral angiograms revealed a basilar bifurcation aneurysm located in the high position. Also, the left internal and external carotid arteries were supplied through the anastomotic muscle branches of the left occipital and vertebral artery. The trunk of the left common carotid artery was not visualised from its origin on the aortogram. CT scan at the level of C6 showed thinning of the left common carotid artery and contrast enhancement study indicated occlusion. Neck clipping of the aneurysm was successfully performed by right trans-sylvian approach. Right zygomatic arch was removed to obtain a wider operative field for avoiding further retraction of the brain tissue. The postoperative course was uneventful except transient disorientation for two weeks. It has been well known that internal carotid artery occlusion may be associated with cerebral aneurysm in some cases. However, it seemed to be a rather rare case that the common carotid artery occlusion due to arteriosclerosis was associated with cerebral aneurysm. Hemodynamic factor was positively suggested for aneurysmal formation in this case.

Adult↗

Homologies between herpesvirus of turkey and Marek's disease virus type-1 DNAs within two co-linearly arranged open reading frames, one encoding glycoprotein A.

The genomes of two avian herpesviruses, Marek's disease virus type 1 (MDV1) and herpesvirus of turkey (HVT), share close homology only within certain DNA regions. One such homologous region of HVT DNA was cloned and sequenced. Two open reading frames (ORFs) were found in the long unique region, ORF1 encoding the glycoprotein A (gA), and ORF2 encoding a still unidentified protein. These two HVT-ORFs are located at almost the same positions as the homologous MDV1-ORFs. The nucleotide sequence homologies between HVT and MDV1 were 73% and 68% for ORF1 and ORF2, respectively. Both the 5'- and 3'-noncoding regions, however, are less conserved. The third letter within every codon of ORF1 and ORF2 showed a mismatch of greater than 50% between the two viruses. The amino acid (aa) sequence homologies between the corresponding putative viral proteins are 83% and 80% for ORF1 (gA) and ORF2, respectively. More than 90% homology was observed in the C-terminal region of ORF1 (gA). Furthermore, the deduced aa sequences for both of the ORFs in these two viruses showed considerable homology to two adjoining genes in herpes simplex virus type 1, the glycoprotein C and UL45 genes.

Amino Acid Sequence↗

Acid secretagogues induce Ca2+ mobilization coupled to K+ conductance activation in rat parietal cells in tissue culture.

Intracellular recordings from cultured parietal cells of the rat gastric fundus showed that carbachol, pentagastrin, histamine (in the presence of isobutylmethylxanthine; IBMX) and dibutyryl cyclic AMP induced hyperpolarizing responses which were sensitive to a K+ channel blocker, quinine. The Ca2+ ionophore, ionomycin, also induced a quinine-sensitive hyperpolarization. Deprivation of extracellular Ca2+ preferentially inhibited the hyperpolarizing responses to histamine (plus IBMX) and to dibutyryl cyclic AMP. Caffeine, oxalate and dantrolene sodium, which are known to affect Ca2+ transport in the endoplasmic reticulum, selectively inhibited the carbachol response. Mitochondrial inhibitors (KCN and carbonylcyanide p-trifluoromethoxyphenylhydrazone) preferentially suppressed the gastrin response. Cytosolic Ca2+ measurements with fura-2 indicated that significant increases in the intracellular concentration of free Ca2+ were induced not only by Ca2+-mediated acid secretagogues (carbachol and gastrin), but also by a cyclic AMP-mediated secretagogue (histamine plus IBMX). Dibutyryl cyclic AMP also increased cytosolic Ca2+ ions. It is concluded that stimulation of receptors to histamine, carbachol and gastrin gives rise to mobilization of Ca2+ ions into the cytoplasm from the different sources, thereby stimulating Ca2+-activated K+ channels in cultured rat parietal cells.

Animals↗

[Antitumor effect and indication of chemoembolization using degradable starch microspheres and regional hyperthermia in patients with hepatocellular carcinoma].

Antitumor effects and indications of chemoembolization using degradable starch microspheres (DSM) and regional hyperthermia were investigated in patients with unresectable hepatocellular carcinoma. Chemoembolization using DSM was performed in 40 cases and fourteen cases were treated with the combination of hyperthermia. Tumor regression rate over 50% was 48% (chemoembolization alone: 42%, combined hyperthermia: 57%). Though one and two year survival rates were 62% and 54% respectively in the treatment with chemoembolization alone, one year survival rate was 91% in the treatment with combined hyperthermia. From the viewpoint of antitumor effect, it was thought that effectual indications of chemoembolization using DSM alone were the cases whose tumor size were below 7 cm and portal invasion were negative. These indications however were spread by the combination of hyperthermia. The DSM, temporary embolus, is suitable for combination of hyperthermia because chemoembolization using DSM can be performed many times. The cases with clinical stage III and obstruction of the first branch of portal veins did not become severe hepatic failure because DSM was temporary embolus. Therefore, from the viewpoint of safety, chemoembolization using DSM has almost the same indications as intra-arterial infusion therapy. These results suggested that chemoembolization using DSM will be a beneficial methods as combination therapy for unresectable hepatocellular carcinoma.

Carcinoma, Hepatocellular↗

Nucleotide sequences of immunoglobulin-epsilon pseudogenes in man and apes and their phylogenetic relationships.

To understand the phylogenetic relationships between hominoids, the nucleotide sequences of immunoglobulin-epsilon processed pseudogenes from chimpanzee, gorilla and orangutan were determined. The basic structures of these processed pseudogenes agreed with their human counterpart. Although the degrees of nucleotide differences between man and the African apes had no statistical significance, all the analytical data examined supported the theory that chimpanzee is the closest relative of man. This result was consistent with that deduced by our recent qualitative study. Studies on the nucleotide sequences of globin genes have suggested that the molecular clock runs more slowly in hominoids than in non-hominoid primates. According to the present data, however, further retardation of the evolutionary rate was not observed in the human lineage. Assuming that orangutan diverged 14 million years ago and that the evolutionary rate between the orangutan lineage and the lineage leading to the other three species is constant, the divergence dates of chimpanzee and gorilla were estimated to be 4.9(+/- 0.9) and 5.9(+/- 0.9) million years ago, respectively.

Animals↗

Comparison of the sequence of the secretory glycoprotein A (gA) gene in Md5 and BC-1 strains of Marek's disease virus type 1.

DNA fragments containing the secretory glycoprotein A (gA) gene of Marek's disease virus type 1 (MDV1) were cloned from the DNA libraries of very virulent Md5 and virulent BC-1 strains and sequenced. Two open reading frames (ORF1 and ORF2) were identified for both strains. The ORF1 has the potential to code for a protein of 501 amino acids with a molecular weight of 56 kD that contains strong hydrophobic regions in both the amino and carboxyl termini, and nine potential N-linked glycosylation sites, while the ORF2 is capable of coding for a 24-kD protein. These results indicate that the ORF1 codes for the unprocessed form of gA. Between the Md5 and BC-1 strains, only two sequence mismatches exist in the DNA fragment. More differences appear to exist in the gA sequence of the MDV1 GA strain (12), which lacks a strong hydrophobic anchor sequence. Similarities between the predicted amino acid sequences of the MDV1 gA and the proteins of the other herpesviruses such as herpes simplex type I gC, pseudorabies virus gIII, and varicella zoster virus gpV were noted.

Amino Acid Sequence↗

Immunohistochemical study on fetal raphe samples transplanted into the leptomeningeal tissue of 5,6-dihydroxytryptamine-treated adult rats.

Pieces of fetal midbrain raphe containing serotonergic and dopaminergic neurons were transplanted into the leptomeningeal tissue of adult host rats that had previously been denervated by treatment with 5,6-dihydroxytryptamine. One, 2 and 5 months after transplantation, the rate of neuronal survival in the grafted tissue and the extent of axonal outgrowth into the host brain were studied by use of serotonin and tyrosine hydroxylase (TH) immunohistochemistry. The survival rate of the grafts in the 1-month group was approximately 70%. Neurons containing either serotonin or catecholamine were demonstrated by means of immunocytochemical procedures in the grafts. Two and 5 months after transplantation, serotonin-immunoreactive nerve fibers were densely distributed throughout the graft tissue, while TH-immunoreactive fiber elements were restricted to an area near the somata of TH-positive neurons. Numerous serotonin-immunoreactive fibers derived from the transplant were found in the leptomeningeal tissue surrounding the graft, on the wall of neighboring blood vessels, and also in the adjacent parenchyma of the host brain. Outgrowing TH-immunoreactive nerve fibers were not observed in the host brain, although such elements occurred in the leptomeningeal tissue and the wall of the larger blood vessels. These results suggest that the serotonergic and catecholaminergic (dopaminergic) neurons located in transplants of the raphe nuclei show different patterns when reinnervating the host tissue.

5,6-Dihydroxytryptamine↗

Probe walking: development of novel probes for DNA fingerprinting.

The tandem repeat of a 28-base-pair (bp) sequence downstream of the human c-Ha-ras-1 oncogene was studied as a probe for DNA fingerprinting. Multiple hypervariable patterns were observed by Southern hybridization at low stringency. The patterns were specific to individuals, indicating the availability of the 28-bp repeat as a probe for DNA fingerprinting. Moreover, we cloned the tandem repeat of a 33-bp sequence, which cross-hybridized with the 28-bp repeat. This 33-bp repeat detected another set of hypervariable restriction fragments by Southern hybridization at the same stringency. These results suggests that 'probe walking' can be employed to develop novel probes that provide different DNA fingerprints.

Blotting, Southern↗

Combined method of fluorescence tracer technique and PAP immunohistochemistry for discrimination of the transplanted cells.

The retrograde fluorescence tracer, True Blue (TB), was injected into the forebrain septal area of neonatal rats. After 3 to 6 days the brains of these animals were carefully removed and placed in ice-cold sterilized physiological saline containing 1% glucose. Under the surgical microscope, one or two pairs of mesencephalic tissue samples, each containing a dorsal raphe nucleus, were punched out and transplanted into the third ventricle of a 5,6-DHT-pretreated adult rat. One month after transplantation, all animals were perfused and their brains sectioned using a cryostat. The sections were examined using a fluorescence microscope, and then processed for serotonin immunohistochemistry. The grafts were found to be successfully implanted and connected with the middle portion of the third ventricle. Four types of neurons, i.e., TB-labeled, serotonin-labeled, both TB- and serotonin-labeled, and non-labeled neurons, were detected in the grafts. This double-labeling method is considered to be a useful technique in characterizing the neurons in grafts which consist of a heterogeneous cell population.

Animals↗

Intestinal secretagogues increase cytosolic free Ca2+ concentration and K+ conductance in a human intestinal epithelial cell line.

A human intestinal epithelial cell line (Intestine 407) is known to retain receptors for intestinal secretagogues such as acetylcholine (ACh), histamine, serotonin (5-HT) and vasoactive intestinal peptide (VIP). The cells were also found to possess separate receptors for secretin and ATP, the stimulation of which elicited transient hyperpolarizations coupled to decreased membrane resistances. These responses were reversed in polarity at the K+ equilibrium potential. The hyperpolarizing responses to six agonists were reversibly inhibited by quinine or quinidine. By means of Ca2(+)-selective microelectrodes, increases in the cytosolic free Ca2+ concentration were observed in response to individual secretagogues. The time course of Ca2+ responses coincided with that of hyperpolarizing responses. The responses to ACh and 5-HT were abolished by a reduction in the extracellular Ca2+ concentration down to pCa 7 or by application of Co2+. Thus, in Intestine 407 cells, not only the intestinal secretagogues, which are believed to act via increased cytosolic Ca2+ (ACh, 5-HT and histamine), but also those which elevate cyclic AMP (VIP, secretin and ATP) induce increases in cytosolic Ca2+, thereby activating the K+ conductance. It is likely that the origin of increased cytosolic Ca2+ is mainly extracellular for ACh- and 5-HT-induced responses, whereas histamine, VIP, secretin and ATP mobilize Ca2+ from the internal compartment.

Calcium↗