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Biomedical subjects

K Ochi

Publications and source records attributed to K Ochi.

At least 163 records · Page 9Linked to original sources
PubMed1986

Role of free radicals in ischemic rat liver cell injury: prevention of damage by alpha-tocopherol administration.

The present study was undertaken to determine whether alpha-tocopherol pretreatment could modify cellular free radical metabolism during hepatic ischemia and subsequent reperfusion and prolong the viability of the liver. Although ischemia of the liver for 90 minutes did not permit survival of the animals, alpha-tocopherol administration (10 mg/kg of body weight) for 3 days increased the survival rate to 45.5%. The period of ischemia was accompanied by decreases in the hepatic adenosine triphosphate (ATP) level, endogenous alpha-tocopherol, and total glutathione (reduced and oxidized) without any significant increase in endogenous coenzyme Q (CoQ) homologs (CoQ9 and CoQ10) and lipid peroxide formation. The subsequent restoration of blood flow resulted in a low recovery of ATP and marked decreases in endogenous alpha-tocopherol, total glutathione, and CoQ homologs and, on the contrary, a marked increase in lipid peroxide levels. In alpha-tocopherol-treated animals, however, resynthesis of ATP was accelerated even after 90 minutes of ischemia, and there were no changes in the levels of total glutathione or CoQ homologs or in the level of the enhanced alpha-tocopherol during the reperfusion period. The pretreatment also completely suppressed the elevation of lipid peroxide levels. These results are compatible with the assumption that cellular damage caused by hepatic ischemia can be explained by free radical reaction processes during ischemia and especially reperfusion and suggest that administration of a free radical scavenger and antioxidant, alpha-tocopherol, is effective in ischemic liver cell injury.

Adenine Nucleotides↗
PubMed1985

Angiotensin converting enzyme. A possible histologic indicator for human renal cell carcinoma.

Angiotensin converting enzyme (ACE) was studied in specimens of human renal cell carcinoma by indirect immunofluorescence using rabbit antibody to human kidney ACE and fluorescein-labeled goat antibody to rabbit immunoglobulin. ACE was demonstrated in the cells of all renal cell carcinomas from 10 patients and in the cultured cells set up from 4 of them, but not in any cells of 12 extrarenal carcinomas of prostate, lung, and alimentary tract. These results suggest that immunohistologic detection of ACE is of value in the histologic diagnosis of renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed1985

Thomsen-Friedenreich antigen in bladder tumors as detected by specific antibody: a possible marker of recurrence.

TUR specimens of non-invasive transitional-cell carcinomas were examined for their expression of Thomsen-Friedenreich (T) antigen by indirect immunofluorescence staining using rabbit IgG antibody which was raised with desialated glycophorin. Nine (45%) out of 20 tumors of low grade (Grade I and II), and 5 (56%) of 9 tumors of high grade (III) were diffusely stained with anti-T (T-positive), whereas T-antigen in normal tissue was cryptic and stained only after neuraminidase treatment (cryptic T-positive). Of the T-negative tumors, 9 (45%) of the low grade but only one of the high grade tumors, were stained positively for the cryptic T-antigen. The rest of the tumors were devoid of the cryptic T-antigen. Eighty percent of both Tumors expressing T-antigen and those lacking the cryptic T-antigen recurred within two years. Recurrence was not influenced by initial histological grade.

Antibodies↗
PubMed1985

Sequential changes of nuclear DNA content caused by chemotherapy in experimental canine gastric cancer.

It is well known that the nuclear DNA content closely correlates with the histologic grade of malignancy. In this study, eight beagle dogs with gastric cancer induced by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) received weekly administration of 7-N-(p-hydroxyphenyl)-mitomycin C (M-83), a variant of mitomycin C. Endoscopic observations were carried out biweekly, and a biopsy specimen was taken from the same tumor site on each occasion. The nuclear DNA content of these biopsy specimens was measured by Feulgen-DNA-cytofluorometry and was sequentially observed in comparison with histologic findings. In conclusion, 1) the appearance rate of cells over 4C decreased from 25.6% to 14.7% on an average (p less than 0.02); 2) the maximum value of distribution decreased from 9.55C to 7.64C on an average (p less than 0.001); 3) the stem line reduced from 2.63C to 2.20C on an average (p less than 0.05) at the early stage of administration of the oncostatic agent prior to the appearance of histologic changes; 4) in the chemotherapy-effective group, the histogram approached a normal pattern; 5) this procedure will be useful for objective evaluation of oncostatic effects at the cytomorphologic level.

Animals↗
PubMed1985

Matrix glycosaminoglycan in urinary stones.

At first, urinary stones were classified according to their inorganic components (apatite, struvite, calcium oxalate monohydrate, calcium oxalate dihydrate and uric acid). Then, matrix glycosaminoglycan was extracted from the stones in each group and was analyzed by 2-dimensional electrophoresis. There were differences in the glycosaminoglycan content of matrices among different groups of urinary stones. The principal matrix glycosaminoglycan content consisted of hyaluronic acid in apatite and struvite stones, heparan sulfate in calcium oxalate monohydrate and uric acid stones, and hyaluronic acid and heparan sulfate in calcium oxalate dihydrate stones. We conclude that hyaluronic acid and/or heparan sulfate has an important role in urinary stone formation.

Electrophoresis↗
PubMed1985

Isometric detrusor pressure in the male patient: a comparison between voluntary urethral sphincter contraction and forced penile compression techniques.

Different functions of detrusor contraction are estimated by measurement of maximum isometric detrusor pressure with voluntary urethral sphincter contraction and forced penile compression flow-stop techniques. Maximum isometric pressure curves with these 2 techniques consist of 2 and 3 phases, respectively. The first phase of each method is a linearly increasing curve whose slope seems to indicate the speed of isometric detrusor contractions. The second phase in the curve obtained by the voluntary flow-stop technique is considered to be an inhibitory phase, while that obtained by the forced technique is considered to be a continuing phase followed by a plateau, the third phase. The maximum isometric pressures obtained with the forced flow-stop technique were statistically higher than those obtained with the voluntary flow-stop technique in patients with enuresis and prostatic obstruction. Although in volunteers the maximum isometric pressure measured with the forced flow-stop technique showed higher values than that measured with the voluntary method there was no statistical difference. There was no statistical difference in the speed of detrusor contractions obtained with either technique in all of the patients except those with urethral stricture, in whom the speed of detrusor contraction measured with the forced flow-stop technique showed a lower value than that obtained with the voluntary method. We believe that the penile urethra distal to the stricture acts as a reservoir when urinary flow is poor. The forced flow-stop technique was necessary to measure maximum isometric pressure in patients with neurogenic bladder dysfunction, many of whom could not stop urinary flow voluntarily.

Adolescent↗
PubMed1985

Possible role of hyaluronate in experimental renal stone formation in rabbits.

We produced renal stones in rabbits by modifying Itatani's method, ligation of the right ureter followed by ureteroneocystostomy 1 week later. Renal stones formed in all animals within 2 weeks after ureteroneocystostomy. We measured the components of glycosaminoglycan in the stone matrix, renal tissue and urine by 2-dimensional electrophoresis. Glycosaminoglycan of the stone matrix consisted solely of hyaluronate. Glycosaminoglycan of the control normal urine consisted of only chondroitin sulfate, although hyaluronate was contained in urine in the hydronephrotic and stone forming period. Glycosaminoglycan of the control normal kidney consisted mainly of hyaluronate and chondroitin sulfate, while hyaluronate was the main component of glycosaminoglycan in the stone forming kidney. From these results, it is clear that hyaluronate is the most important component of glycosaminoglycan in the early stone forming period.

Animals↗
PubMed1985

Architecture of calcium oxalate monohydrate urinary calculi.

We have developed a partial dissolution method which enabled us to observe the internal architecture of urinary calculi. Using this method with improved organic matrix fixative, we studied the architecture of small calcium oxalate monohydrate urinary calculi with special attention to crystal-matrix interrelations. Calculi, we have observed, are invariably composed of 3 distinct zones. A core area is composed of randomly aggregated plate-like crystals with tendency of rosette formation. This core area is surrounded by an intermediate layer which shows prominent radial striations. This layer is composed of radially arranged piles of sheet-like crystals which extend beyond many layers of lamination. This layer gradually shifts to a peripheral layer where concentric laminations are prominent and each layer of lamination is composed of minute crystals which have lost radial arrangement. The organic matrix is observed only at the outside of the crystals, and matrix-rich crystal-poor bands separate each layer of concentric lamination. The concentric lamination seems to be a manifestation of the altered density of organic matrix which encrusted on the developing calculi and offered a milieu for crystal growth within.

Calcium Oxalate↗
PubMed1985

Duration of ENNG administration and its effect on histological differentiation of experimental gastric cancer.

An experimental trial in the induction of canine gastric cancers was conducted to study the relationship between the histological differentiation of adenocarcinoma and the duration of administration of the carcinogen, N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG). Twenty-three adult Beagle dogs were divided into three groups according to the duration of administration. Over 3 months administration, the total dose of ENNG per animal was 5.85 g, and only signet ring cell carcinomas and poorly differentiated adenocarcinomas were induced in the antral mucosa of the stomach in 5 of 10 recipients. During 6 and 9 months administration, the total doses per animal were 11.70 g and 17.55 g, well differentiated adenocarcinomas were observed in 12 of 13 animals and they coexisted with poorly differentiated adenocarcinomas and/or signet ring cell carcinomas. Atrophic hyperplastic gastritis and hyperplastic polyps were seen in the same stomach. The results of this study suggest that a greater amount of carcinogen, i.e., a higher total dose, is required for the development of well differentiated adenocarcinoma than for inducing poorly differentiated adenocarcinoma and signet ring cell carcinoma.

Adenocarcinoma↗
PubMed1985

Pharmacological enhancement of recovery in experimental hydronephrosis.

The effects of mannitol, methylprednisolone, furosemide, inosine, indomethacin and captopril on the recovery from hydronephrosis were examined in rat kidneys. After 1 week of ureteral obstruction, left ureterocystostomy was performed in order to release the obstruction. Following ureteral release, mannitol, methylprednisolone, inosine, furosemide, captopril and indomethacin were given intravenously or orally. A saline group and non-treated control rats were also examined for comparison. 4 weeks after ureterocystostomy, 0.5 microCi of 203Hg-labelled chlormerodrin was given intravenously and the animals were sacrificed 48 h later. The left kidneys were significantly heavier in the mannitol-, methylprednisolone-, and inosine-treated groups than those of the control groups. The chlormerodrin uptake ratios of the left kidneys were significantly higher in the mannitol-, methylprednisolone-, captopril- and indomethacin-treated groups than in the control groups. These results suggest that the release of obstruction solely is not complete treatment for hydronephrosis, but that appropriate medical treatment may enhance the recovery from hydronephrosis.

Animals↗
PubMed1985

[Endoscopic and histopathological studies of experimental esophageal cancer in beagles].

In order to obtain a reliable experimental model simulating human esophageal cancer, endoscopic and histopathological studies were undertaken in the esophageal cancer produced in the beagle dog. Thirty-seven dogs had been given a solution of N-Ethyl-N'-nitro-N-nitrosoguanidine (ENNG) at a concentration of 150 micrograms/ml for 3-9 months. Follow-up studies included serial endoscopy and biopsy, and almost all animals were eventually sacrificed for histological examination. The results were as follows: Squamous cell carcinoma was observed in 5 out of 22 female dogs, while none in male dogs at all. For the induction of squamous cell carcinoma in the esophagus, administration in the condition of 150 micrograms/ml (75mg/day) for 6-9 months was most suitable. Almost all of esophageal lesions were protruding and well-differentiated squamous cell carcinoma with invasion of the submucosa. The stages of hyperplasia, dysplasia and squamous cell carcinoma in the esophagus were chronologically followed. Carcinoma had been observed in the stomach about 4 months prior to the appearance of esophageal carcinoma. This experimental model was proved to be useful for studies on histogenesis of human esophageal cancer both light and electron microscopically.

Animals↗
PubMed1984

Studies on arachidonate 5-lipoxygenase of rat basophilic leukemia cells.

Arachidonate 5-lipoxygenase was partially purified from rat basophilic leukemia cells with the aid of ATP as a ligand linked to Sepharose. The enzyme produced predominantly 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid. Calcium ion was required for the enzyme activity (0.1 mM for half maximal activity), and the calcium-dependent reaction was stimulated by ATP and several nucleotides. 5,8,11,14,17-Eicosapentaenoic acid was converted to its 5-hydroperoxy derivative at a higher rate than arachidonate oxygenation. 5,8,11-Eicosatrienoic acid as substrate was almost as active as arachidonic acid. Among various lipoxygenase inhibitors tested, cirsiliol, a flavone derivative, was the most potent.

Animals↗