Search PubMed⌕ Search

Biomedical subjects

A Harada

Publications and source records attributed to A Harada.

At least 235 records · Page 13Linked to original sources
PubMed1992

The effects of gamma-glutamylcysteine ethyl ester, a prodrug of glutathione, on ischemia-reperfusion-induced liver injury in rats.

This study was designed to clarify the effects of changes in liver tissue glutathione (GSH) concentration on postischemic liver injury together with the effects of gamma-glutamylcysteine ethyl ester (GCE), a prodrug of GSH, and GSH. Rats were pretreated with GSH (50 mg/kg, i.v.), or GCE (50 mg/kg, i.v.), or untreated. In each rat, liver was isolated, and liver mitochondria were prepared after 2 h of ischemia or 1 h of reperfusion following 2 h of ischemia. Mitochondrial function was measured polarographically. Liver adenine nucleotide concentrations were also determined using high-performance liquid chromatography. Liver tissue GSH, an oxidized form of glutathione (GSSG) concentrations, and activities of GSH peroxidase and GSSG reductase were determined enzymatically. Liver hypoxanthine and xanthine concentrations were determined by HPLC. Liver tissue concentration of lipid peroxide was measured. Leakages of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and adenine nucleotides into the hepatic vein after reperfusion were also measured. Administration of GCE improved the recovery of mitochondrial function and maintained tissue GSH concentration concomitantly. Increases in liver lipid peroxide concentration after reperfusion, and leakage of liver cell enzymes and adenine nucleotides were mitigated by administration of GCE. Administration of GSH itself failed to maintain tissue GSH concentration and had no protective effects. From these results, it is concluded that in the postischemic process, free radical formation might be enhanced, and the radical scavenging system deteriorated. To enhance the radical scavenging system is a possible maneuver to prevent radical-related cell damage associated with reperfusion, because pharmacological reduction of breakdown of ATP to hypoxanthine and xanthine seems to be difficult. GCE maintained liver GSH concentrations and mitigated postischemic liver injury, concomitantly. Clinical use of GCE might be recommended.

Adenine Nucleotides↗
PubMed1992

An unusual case of accidental smothering.

A rare accidental death case is presented in which four pieces of packing tape adhered tightly over the nose and mouth. The notes for his experimental report, left in his room, suggested that the accident happened during his trial to prove his theory on respiration to improve physical exercise.

Adult↗
PubMed1992

Ultrastructural studies of the bile duct in alcoholic liver disease.

The fine structural characteristics of the bile duct in patients with alcoholic disease are described. Dark cell metamorphosis, edematous microvilli, and increased number of pinocytotic vesicles on the basal wall surface of the duct epithelium were observed. These alterations may be interpreted as evidence of disordered water metabolism, probably reflecting secretion and reabsorption hyperfunction in the duct epithelium. In addition, widened intercellular spaces in the basal half of the epithelium suggested retention of fluid following reverse pinocytosis along the lateral cell surface. Although no alterations of the duct epithelium distinct from those in patients with other liver diseases were apparent in patients with alcoholic liver disease, the basement membrane of the bile duct exhibited unusual duplication with multiple layers and occasional loop-formation in lacunae on the basal surface.

Adult↗
PubMed1992

Changes in the glutathione redox system during ischemia and reperfusion in rat liver.

After 60 min of reperfusion following 60 min of ischemia, the ischemia-induced decrease in liver tissue adenosine triphosphate (ATP) concentration had recovered by 66%, and full recovery of mitochondrial function--that is, the respiratory control index (RCI) and the rate of oxygen consumption in state-III respiration (ST III O2)--was observed. In contrast, liver tissue ATP concentration had recovered by only 13%, and marked low RCI and ST III O2 were observed after 60 min of reperfusion following 180 min of ischemia. Intermediate results were observed in rats after 60 min of reperfusion following 120 min of ischemia. Liver tissue hypoxanthine and xanthine, substrates of xanthine oxidase, increased ischemic time dependently. Liver tissue concentrations of the reduced form of glutathione (GSH) and the oxidized form of glutathione (GSSG) and activities of glutathione peroxidase and glutathione reductase did not change after 60 min of reperfusion following 60 min of ischemia. In contrast, GSH concentration and glutathione peroxidase activity decreased significantly after 60 min of reperfusion following 180 min of ischemia. Since the glutathione redox system is an important contributor to the scavenging of free radicals after reperfusion following a long time of ischemia, the free radical scavenging ability might decrease in spite of enhancement of free radical generation, which might play an important role in the inhibition of the recovery of tissue ATP concentrations and mitochondrial function.

Adenosine Triphosphate↗
PubMed1992

[Two cases of esophageal varices complication after hepatic arterial infusion chemotherapy (HAI) for metastatic liver tumor].

Mild liver dysfunction is a well-known complication of HAI, but it has been thought to be transient and reversible in most cases. In the case, of metastatic liver disease, in particular, HAI has been performed safely because liver function is normal for the most part. We encountered 2 cases of irreversible severe liver dysfunction and esophageal varices after hepatectomy for metastatic liver tumor from colorectal cancer. They were treated with postoperative adjuvant HAI. Biliary enzyme as alkaline phosphatase elevated, and dilated intrahepatic bile ducts were observed in both patients. Fibrosis of Glissonean sheath, dilatation of intrahepatic bile ducts and intrahepatic biliary stones were observed at autopsy in both patients. One of the patients had obstruction of portal trunk. It must not be forgotten that such complications can occur even in a case with non-cirrhotic liver.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[The results and problems of surgical treatment of cancer of the duodenal papilla of Vater].

Twenty six of 28 cases (92.9%) of cancer of duodenal papilla of Vater were resected from 1981 to 1990. Twenty five pancreatoduodenectomy and one total pancreatectomy were performed. Operative death and hospital death were not observed. Three year and five year cumulative survival rates of resected cases were 58% and 52% respectively. There was relatively good correlation between pathological cancer extension and postoperative prognosis. Postoperative prognosis of the cases which had cancer extension to the pancreas was extremely poor. But the prognosis of the cases of cancer within Oddi muscle was extremely good. Immunohistochemical staining using anti CEA, anti CA19-9 and anti DUPAN 2 was studied and Grade III staining pattern was observed only in the cases which had cancer invasion to the pancreas. Preoperative diagnosis of cancer extension using endoscopic ultrasonography and appropriate choice of the operative procedure are important. Extended operation and effective adjuvant therapy are necessary for advanced cases of cancer of the duodenal papilla.

Adult↗
PubMed1992

[Long-term results of terminal esophago-proximal gastrectomy for esophageal varices].

Between 1973 and 1991, 193 patients underwent terminal esophagoproximal gastrectomy (TEPG) for esophageal varices. One hundred and sixty patients (84%) were cirrhotics. Ten patients (5.2%) were died within hospital stay. In 116 elective patients who had been free from hepatocellular carcinoma during therapeutic courses, the 5- and 10-year survival rates were 77% and 62% in Child A, and 62% and 38% in Child B, respectively. There was a significant difference between the two groups (p < 0.05). Postoperative rebleeding from esophageal varices was infrequent within 5 years but increased after 5 years especially in Child B and Child C. For patients with these recurrent varices, endoscopic injection sclerotherapy was very effective and improved the prognosis. The survival rate of patients with extremely decreased platelet counts was not different from that of patients without. There were no other severe complications after TEPG. We conclude that TEPG would be indicated firstly for elective or prophylactic cases unless they have severe hepatic damage.

Esophageal and Gastric Varices↗
PubMed1992

[Clinicopathological study of membranous glomerulonephritis in patients with rheumatoid arthritis].

Of 103 patients with membranous glomerulonephritis proved by renal biopsy, 11 (10.7%) had rheumatoid arthritis. Nine of these 11 patients received systemic treatment with anti-rheumatic remedies including gold, D-penicillamine and bucillamine. Two others were administered only token of nonsteroidal antiinflammatory drugs. Renal function of the patients was well maintained and within normal limits. Four patients showed nephrotic syndrome, while mild to moderate proteinuria was found in the other 7. Hematuria was minimal to mild, and it was not a major symptom. Six patients resolved proteinuria completely and 2 patients incompletely after discontinuation of chrysotherapy. Nine cases of the membranous lesion in patients with rheumatoid arthritis were stage 1. Thus it was often difficult to identify the glomerular change only by light microscopy. IgA nephropathy and AA amyloidosis were associated in one patient respectively. Our data lead us to conclude that chrysotherapy would cause membranous lesions, but rheumatoid arthritis itself also induce membranous glomerulonephritis.

Adult↗
PubMed1991

Dieulafoy's ulcer associated with the tortuous caliber persistent arteries: report of three cases.

Many papers have reported that Dieulafoy's ulcer is one of the notorious causes of gastric hemorrhage. Three cases of shallow subfundic ulcers with massive bleeding are reported. The resected specimens have demonstrated that elevated caliber-persistent artery (CPA), a branch of the left gastric artery with few anastomoses, in the base of the ulcer has tortuous penetration from the serosa to submucosa, showing patchy, eccentric intimal fibroelastosis. These findings of CPA are almost the same in both anterior and posterior walls, namely both the ruptured and contralateral sides. Thus, morphogenesis of the ulcer may have originated from anatomical deviation, which is related to regional hypertension aggravated by longterm peristalsis, as well as aging.

Aged↗
PubMed1991

Purification of achatin-I from the atria of the African giant snail, Achatina fulica, and its possible function.

Achatin-I previously purified from the ganglia of the African giant snail Achatina fulica was isolated from the atria of this snail. Achatin-I appeared to enhance the cardiac activity in two ways; centrally this peptide increased impulse frequency and produced spike broadening of the identified heart excitatory neuron, PON, and peripherally it enhanced amplitude and frequency of the heart beat. Achatin-I showed excitatory actions not only on the heart but on several other muscles.

Amino Acid Sequence↗
PubMed1991

Primary structure of the virus activating protease from chick embryo. Its identity with the blood clotting factor Xa.

Host cell proteases activating para- and orthomyxovirus fusion glycoprotein precursors play a crucial role in determining the viral tropism in infected organisms. We previously isolated such an endoprotease from the allantoic fluid of chick embryo and showed its close similarity to the activated form of blood clotting factor X (FXa) by partial amino acid sequencing. In this report, we have cloned and sequenced a cDNA of the protease, and show that it is encoded in a single gene as a preproform with all the functional and structural domains known to be characteristic of bovine or human FX, establishing the identity between the protease and FXa.

Allantois↗
PubMed1991

Facile assignment of sequence ions of a peptide labelled with 18O at the carboxyl terminus.

The combination of collision-induced dissociation (CID) and linked-scan analysis was used for analysing the sequence ions from the precursor ion of a peptide, which had been labelled with 18O at its carboxyl terminus (C-terminus) using 40 atom % H2 18O. The CID and linked-scan mass spectrum of the labelled peptide gave two series of sequence-ion signals: the one, originating from the C-terminus of the labelled peptide, showed a doublet signal due to the part-incorporation of 18O into the carboxyl group at the C-terminus, while the other, originating from the amino terminus (N-terminus), has the natural isotopic ion distribution. From the distribution of the isotopic ions in a single CID spectrum, the sequence ions containing the C-terminus could be readily differentiated from those containing the N-terminus, allowing the facile assignment of sequence ions to the amino-acid sequence of a peptide by CID and linked-scan analysis. This method was successfully applied to determination of the amino-acid sequence of the light-chain of mouse anti-porphyrin monoclonal antibody.

Amino Acid Sequence↗
PubMed1991

Quality control program on biological monitoring by Japan Federation of Occupational Health Organizations.

Since 1980, the Japan Federation of Occupational Health Organizations has been conducting an external quality control survey for biological monitoring under a contract with the Ministry of Labour of the Japanese Government. The number of participating organizations has increased from 91 in 1980 to 179 in 1987. The items in the program were lead and free erythrocyte protoporphyrin concentrations in blood, and lead, coproporphyrin, delta-aminolevulinic acid, chromium, hippuric acid, methylhippuric acid, total trichloro-compounds, mandelic acid, and phenol concentrations in urine. Evaluation was based on a scoring system. The scores were on the slope of major axis for probable ellipse, the slope of regression line, square root of error mean square for regression, performance indices, and the difference between 'true' and observed values of each sample. There was a gradual improvement in the evaluation scores as a function of time. The improvement was paralleled by the adoption of modern analytical methods such as flameless atomic absorption spectrometry for blood-lead measurement and high-performance liquid chromatography for urinary hippuric acid determination in many participants. These methods are simple in operation and reliable in performance. It was considered very probable that the program promoted the adoption.

Environmental Monitoring↗
PubMed1991

A novel point mutation at codon 146 of the K-ras gene in a human colorectal cancer identified by the polymerase chain reaction.

In this report, point mutations of the K-ras gene at codon 146 were analyzed in 25 cases of colon cancer, 4 cases of lung cancer, and 41 cases of lymphoid malignancy. A codon 146 mutation substituting threonine (ACA) for alanine (GCA) was detected in the tumor tissue of a patient with colon cancer and was not detected in the normal tissue of the same patient. Any additional mutations of the ras gene family were not detected in this patient. These results suggest that the codon 146 mutation of the K-ras gene could be involved in the development of naturally occurring human malignancies.

Antisense Elements (Genetics)↗
PubMed1991

Mucin-histochemical and immunohistochemical profiles of epithelial cells of several types of hepatic cysts.

Epithelial cells of several types of hepatic cysts were examined by mucin histochemistry and immunohistochemically. There were some differences in mucus and antigenic expression among the hepatic cysts examined. Epithelial cells of non-parasitic simple cysts and adult-type polycystic liver showed similar mucin-histochemical and immunohistochemical features, and were characterized by little mucin and weak immunoreactivities to several antibodies examined. Epithelial cells of hepatic hilar cysts were characterized by much mucin and moderate immunoreactivities to carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Epithelial cells of ciliated hepatic foregut cysts were characterized by much mucin and immunoreactivities to actin and tubulin which were positive in cilia. Epithelial cells of biliary cystadenoma were characterized by much mucin and moderate to strong immunoreactivities to cytokeratins CAM5.2 and AE1 and 3 as well as to CA 19-9, CEA, EMA and DU-PAN-2. Epithelial cells of biliary cyst-adenocarcinoma were characterized by much mucin and moderate to strong immunoreactivities to cytokeratins CAM5.2 and AE1 and 3 as well as to CA 19-9, CEA, EMA and DU-PAN-2. These differences in epithelial mucus and antigenic expression among several types of hepatic cysts may reflect differences in their origin and biological characteristics. These differences may be helpful in the differential diagnosis of hepatic cysts in small biopsy specimens.

Antigens↗
PubMed1991

The potential role of postoperative hepatic artery chemotherapy in patients with high-risk hepatomas.

The relationship between operative findings of hepatoma and the postoperative prognosis was studied to clarify indications for adjuvant hepatic arterial chemotherapy after hepatectomy. The results of adjuvant hepatic arterial chemotherapy using 0.4 mg/kg of doxorubicin and 0.12 mg/kg of mitomycin C and infusion of 5-fluorouracil were reported. One hundred sixty patients who had undergone hepatectomy for hepatoma were studied. In the operative findings of hepatoma, with a surgical margin of less than 10 mm, intrahepatic metastasis, tumor embolus in the second or more proximal branch of the portal vein, or lack of capsule formation related to the prognosis were the risk factors for recurrence. In 132 patients with these risk factors the survival rate of 19 patients with adjuvant arterial chemotherapy was significantly higher than for the 113 patients without it. Adjuvant hepatic arterial chemotherapy thus may be an effective therapy and should be studied prospectively in patients undergoing hepatectomy for high-risk hepatoma.

Adult↗