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Biomedical subjects

M Katoh

Publications and source records attributed to M Katoh.

At least 325 records · Page 18Linked to original sources
PubMed1987

Cystic cemento-ossifying fibroma of the ethmoidal cells (a case report).

A case report of an aggressive cystic cemento-ossifying fibroma of the ethmoidal cells is presented. Fibro-osseous lesions containing cementum are considered to be of periodontal membrane origin and are most common in the mandible and maxilla. Following the WHO classification, fibro-osseous lesions containing cementum are grouped together under the heading of cementoma and are divided into four subgroups. Cemento-ossifying fibroma is considered to be a variant of cementifying fibroma which is a sub-group of cementoma. The unique site of origin seen in this case is thought to have been the result of an ectopic periodontal membrane or of a primitive mesenchymal cell rest or incomplete migration of the medial part of the nasal anlage and differentiation into the periodontal membrane.

Adolescent↗
PubMed1987

High-molecular-weight cadmium-binding proteins in rat liver cytosol: isolation and partial characterization of an approximately 50-kDa protein.

The time-dependent changes in the chromatographic pattern of subcutaneously injected cadmium associated with non-metallothionein cadmium-binding proteins were studied in the rat liver cytosol. Prior to the induction of cadmium-thionein (less than 3 h), cadmium appeared in three major peaks (P-1 with the void volume, P-2 and P-3) on Sephacryl S-300 column chromatography. Accompanied with the emergence of apo-metallothionein (about 3 h after administration), the amount of P-3 decreased and instead a cadmium-thionein peak (P-4) increased. Ion-exchange chromatography of P-3 with a combination of CM and DEAE Bio-Gel columns showed the existence of three major cadmium-binding proteins with molecular sizes of 46 kDa (in the CM Bio-Gel column eluate), 50 kDa (in the DEAE Bio-Gel column eluate), and 41 kDa (in the non-adsorbed fraction). The cadmium-binding protein in the CM Bio-Gel column eluate was purified to apparent homogeneity. The purified protein (CM-CdP) was 47 or 53 kDa in molecular size as determined by SDS-polyacrylamide gel electrophoresis or gel filtration chromatography, respectively. The apparent dissociation constant and maximum binding for cadmium were about 1 microM and 1 mol of the metal/mol of protein, respectively. The isoelectric point was estimated to be 8.8. The amino acid composition showed that the protein was relatively rich in glutamyl (including its amide) and alanyl residues. The N-terminal amino acid sequence was determined as Ala-Pro-Ile-Ala-Gly-Lys-Lys-Ala-Lys-Ala-Gly-Ile-Leu-Leu-Gly-. In-vitro experiments revealed that cadmium bound to CM-CdP could be easily transferred to apo-metallothionein, confirming that the affinity for the metal of the former protein was lower than that of the latter.

Amino Acid Sequence↗
PubMed1987

Glucocorticoid receptor in multiple myeloma.

Glucocorticoid receptor levels of myeloma cells were quantitated in 7 patients with multiple myeloma. In 4 patients, glucocorticoid receptor levels were less than 10 fmol/10(6) cells. In 3 patients, receptor levels were from 17.6 to 21.4 fmol/10(6) cells. We further examined the correlation between glucocorticoid receptor levels and effect of dexamethasone on 14C-thymidine incorporation and cell viability using 2 myeloma cell lines, OPM-1 and OPM-2, established from a patient with multiple myeloma. Glucocorticoid receptor levels of OPM-1 and OPM-2 were 8.5 fmol/10(6) cells and 63.2 fmol/10(6) cells, respectively. The sensitivity of OPM-1 to dexamethasone in these studies was lower than that of OPM-2. These results suggest the possibility that the low level of glucocorticoid receptor in myeloma cells may be important for predicting a poor response to glucocorticoid therapy.

Cell Line↗
PubMed1987

Hepatic prolactin receptors in the rat: characterization using monoclonal antireceptor antibodies.

Monoclonal antibodies (mAbs) to the rat hepatic PRL receptor were produced and used for characterization of the receptor. A microsomal fraction from female rat liver was solubilized, purified 300- to 500-fold by affinity chromatography, and injected into mice. Two hybridoma clones (E21 and E29) were established, and immunoglobulin G fraction was obtained. Both E21 and E29 at 200 micrograms/ml could inhibit [125I]ovine PRL (oPRL) binding to microsomes from rat liver by 40% and 95%, respectively. E29 also inhibited PRL binding to solubilized receptors, whereas E21 stimulated PRL binding by about 50%. The action of E21 was markedly attenuated when [125I]human GH (hGH) was used as tracer in both microsomal (inhibition) and solubilized (stimulation) receptors. Specificity studies using microsomes from other tissues showed that both mAbs were specific to rat tissues (mammary gland, ovary, prostate, testis, and adrenal) and did not cross-react with tissues from other species (rabbit, mouse, human, pig, and cat) examined. Immunoprecipitation of PRL receptors with mAbs were assessed using 125I-labeled or [125I]oPRL-labeled PRL receptors. Both E21 and E29 were capable of immunoprecipitating a 44,000 mol wt band, the migration of which on a sodium dodecyl sulfate-electrophoresis gel was not affected by the absence or presence of a reducing agent. Only E21 was able to precipitate [125I]oPRL-receptor complexes. Binding studies of 125I-labeled mAb to microsomal receptors showed that oPRL could inhibit 90% of specific E29 binding, whereas inhibition of E21 binding was only 30%. Immunoblotting of PRL receptors confirmed the finding of immunoprecipitation; a band with a similar mol wt was identified with E21, although two closely located bands could be distinguished. There was no reaction in the presence of a reducing agent. These studies demonstrate that E21 recognizes a region distinct from the lactogen-binding site, while E29 binds to a closely related but not completely coincident domain; those regions recognized by both antibodies are specific to PRL receptors in the rat but not to those in other species; from immunoprecipitation and immunoblotting studies, the mol wt of the PRL receptor (or its subunit) is estimated to be 42-46K, similar to that reported for the rabbit mammary gland; this receptor molecule does not appear to bind to other receptor molecules through disulfide linkages; and hGH appears to recognize the PRL receptor-binding site in a somewhat different manner from that of oPRL.

Animals↗
PubMed1987

[Extracorporeal circulation for renal cell carcinoma with supradiaphragmatic caval thrombus].

Removal of the tumor thrombus extended into the intrapericardial vena cava, was accomplished under direct vision with minimal blood loss in a patient with renal cell carcinoma. The liver was mobilized to expose the retrohepatic vena cava by incision of the falciform, triangular and coronary ligaments, and cardiopulmonary bypass was used to create a bloodless field avoiding the migration of tumor thrombus and uncontrollable hemorrhage. Tumor thrombus was delivered intact with a 20 Fr. Foley catheter. Vena cava surgery was done for the tumor invasion, and an artificial vascular graft was then sutured to replace the caval wall. We believe that this technique can be effectively used in selected patients with extensive intracaval involvement of renal cancer.

Blood Vessel Prosthesis↗
PubMed1986

Altered glomerular localization of heparan sulfate proteoglycan in experimental nephritides.

The distribution of heparan sulfate proteoglycan (HS-PG) was examined electron microscopically by the high iron diamine (HID) method in puromycin aminonucleoside (PAN) nephrosis, accelerated Masugi nephritis (NTN), and serum sickness nephritis induced by bovine serum albumin (BSA nephritis) in the rat. In PAN nephrosis rats, no change was observed in the distribution of HS-PG in the lamina rara externa (LRE) of the glomerular basement membrane (GBM) throughout the experiment. In NTN rats, however, the loss of HS-PG was observed, and it was associated with subepithelial electron dense deposits formed possibly by serum sickness mechanism, but not with inflammatory cell infiltration. In BAS nephritis, immune deposits were seen in mesangial, subendothelial, intramembranous and subepithelial areas. The deposits in the former three areas seemed to have little reciprocity with the loss of HS-PG and proteinuria. Urinary protein increased in accordance with the development of subepithelial deposits and the loss of HS-PG in the area of the deposits in the LRE. These results indicate that HS-PG could be preserved even in marked proteinuric states in morphologically intact basement membrane, but altered and lost distribution of HS-PG associated with subepithelial immune deposits could in turn result in the development of proteinuria.

Animals↗
PubMed1986

Acceleration of liver regeneration by malotilate in partially hepatectomized rats.

The effect of malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) on liver regeneration was studied by using partially hepatectomized rats. Malotilate administration (100 mg/kg/day, p.o.) facilitated the weight gain of the liver after partial hepatectomy. Protein, RNA and DNA contents of the regenerating liver correlated well with the weight gain. The weight gain, RNA and DNA contents, and mitotic index were significantly suppressed in the alloxan-diabetic rats 24 hr after partial hepatectomy. However, malotilate administration significantly improved the delayed recovery of RNA content. Other parameters were not significantly improved by malotilate, but tended to increase to a level comparable to those of partially hepatectomized control rats. These results show that malotilate accelerates cell proliferation, resulting in facilitated liver regeneration in rats (as well as in alloxan-diabetic rats).

Alloxan↗
PubMed1986

[Protective effect of malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) on chemical-induced hepatotoxicity].

Protective effect of malotilate on the liver injuries induced by several hepatotoxins was studied in mice and rats. Malotilate suppressed the elevation of plasma glutamate pyruvate transaminase (p-GPT) activity induced by chloroform (CHCl3) in rats when the animals were treated with 25 mg/kg or more dose of malotilate at 6 hours prior to the treatment with CHCl3. The effect was observed even in the rats treated with malotilate 24 or 48 hours prior to the treatment with CHCl3. Malotilate, when orally administered 6 hours prior to treatment with hepatotoxins such as CHCl3, allyl alcohol, bromobenzene, dimethylnitrosamine or thioacetamide, suppressed the elevation of p-GPT activity, liver triglyceride content and/or the decrease of bromosulphalein clearance induced by these hepatotoxins in mice. Anethole trithione, which was used as a possible protective agent against chemical-induced hepatotoxicity, tended to normalize changes in the parameters induced by the most of these hepatotoxins, but enhanced the elevation of p-GPT activity induced by CHCl3. In a case of CHCl3-induced liver injury, the protective effect of malotilate was histopathologically confirmed. Malotilate and anethole trithione reduced p-nitroanisole 0-demethylation activity in rat liver 6 hours after the administration but increased or tended to increase the activity 48 hours after the administration. Malotilate showed a protective effect on the liver injury induced by CHCl3 even when the activity of drug metabolizing enzymes in the liver was increased, although anethole trithione enhanced the CHCl3-induced liver injury regardless of the activity of drug metabolizing enzymes.

Alanine Transaminase↗
PubMed1986

Anti-fibrotic effect of malotilate on liver fibrosis induced by carbon tetrachloride in rats.

The effect of malotilate on liver fibrosis of rat induced by carbon tetrachloride (CCl4) was studied. CCl4 was given subcutaneously (1.5 ml/kg) to male Wistar rats twice a week for 11 weeks. Administration of malotilate (100 mg/kg) 5 times a week was started in the 5th experimental week and continued thereafter. The biochemical parameters in serum such as concentration of total protein and transaminase activities were improved by malotilate administration. The livers treated with CCl4 only were atrophic and markedly nodular, and histologically, severe collagen deposition and pseudolobular formation were observed. However, the livers treated with CCl4 and malotilate showed only slight accumulation of collagen fibers although hypertrophic and fatty metamorphosis was observed. Immunocytochemically, type I and type III collagens were stained in livers from rats treated with CCl4 only and rats treated with CCl4 and malotilate, but stainability was rather weak in the latter. The increased amount of hydroxyproline in the liver and that excreted into urine were markedly suppressed by malotilate administration. The levels of protocollagen prolyl hydroxylase activity in the liver were almost the same in CCl4-treated and CCl4 and malotilate-treated rats. However, the levels of collagenolytic enzyme activity were slightly higher in the latter. From these results, anti-fibrotic action of malotilate was clear and involvement of enhanced collagenolytic enzyme activity was suggested.

Animals↗