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Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

At least 523 records · Page 29Linked to original sources
PubMed1989

Immunohistochemical localization of two types of carbonic anhydrase isozymes in oncocytoma and oncocytic epithelial cells.

An immunohistochemical study was performed on the localization of carbonic anhydrase isozymes I and II (CA I and CA II, respectively) in oncocytoma and oncocytic epithelial cells. Tumors examined were those deserved to be called oncocytomas such as Warthin's tumor, Hürthle cell tumor of the thyroid gland and renal oncocytoma. In addition, the same immunostaining was done on several pathologic lesions, accompanying moderate number of cells similar in tinctorial character to oncocytes, such as some type of adenoma of the thyroid gland, endometrial hyperplasia, endometriosis and so on. Specific antibodies against CA I and CA II prepared from human erythrocytes were converted into Fab' fragment and labeled with horseradish peroxidase. In each tissue sample, the majority of oncocytes or oncocytic epithelial cells showed a tendency to exhibit an immunostaining reaction for CA I and II intenser than that of adjacent original normal epithelium from which they might derive. To the authors' knowledge, no reports have been appeared on biological relevance of an increased activities of carbonic anhydrase in conjunction with a large number of mitochondria appearing in such oncocytic cells. In the present study, it is revealed that the immunoreactivities of CA isozymes increased in oncocytes as the number of mitochondria increased, suggesting that oncocytes have a high level of carbonic anhydrase for catalyzing the hydration of an increased amount of carbon dioxide generated chiefly via oxidative metabolism by mitochondria, the number of which is notably increased compensatorily for their deficient coupling of oxidative phosphorylation or other metabolic anomaly.

Adenoma↗
PubMed1989

Ultrastructural histochemistry of carbonic anhydrase in rat osteoclasts.

Carbonic anhydrase (CA) was localized in osteoclasts of rat tibial metaphysis by light and electron microscopy using the histochemical method of Hansson. Ultrastructurally, positive staining was seen in the cytosol, mitochondrial cristae, Golgi apparatus, some nuclei and lysosomelike vesicles, and on the bone surface beneath the osteoclast. The presence of the enzyme within the Golgi ++apparatus, lysosomelike vesicles, and on the bone surface beneath the osteoclast suggests that some CA may be secreted into the resorbing zone. According to literature, the above localization of CA suggests that there may be three isozymes of CA in the rat osteoclast. These are ubiquitous cytosolic CA (CA-II), mitochondrial CA (CA-V) and secretory CA (CA-VI).

Animals↗
PubMed1989

[Cis-dichlorodiammineplatinum in osteosarcoma. Osteosarcoma Cooperative Study Group report].

Thirty-two patients with primary osteosarcoma and 18 patients with advanced osteosarcoma were treated by iv or ia infusion of cisplatinum at a dose of 100 mg/m2 every three weeks. The efficacy of the agent for primary osteosarcoma was mainly estimated by X-ray findings and histologic examination. One patient had a partial response, and 7 patients had a minor response. Pathologic evaluation of the extent of the primary tumor necrosis was performed on 27 resected specimens. Eight of 27 cases showed a good response (Ayala III A less than). One of 18 patients with advanced osteosarcoma had a partial response, and 2 a minor response. Nausea and vomiting (88%), liver dysfunction (42%), leukopenia (36%), nephrotoxicity (20%) and auditory disturbance (20%) were the main side effects in 50 patients. However, side effects of cisplatinum were generally reversible. The results suggest that cisplatinum is effective against osteosarcoma and may enhance the therapeutic results in osteosarcoma.

Adolescent↗
PubMed1989

[Auditory brainstem response in dead on arrival cases].

The relationship between ABR on the one hand and acid-base balance, EEG findings and prognosis on the other was studied in 47 cases of DOA. As for the acid-base balance, the balance tipped to acidosis in almost all cases. The ABR showed wave I to wave V in 25 cases, wave I to wave III in 2 cases and only wave I or no response in 20 cases on the admission day. The EEG was isoelectric in 27 out of 35 cases. All the patients who showed some activity in EEG had ABR which showed waves I through V. However, 11 of the 27 patients who were isoelectric EEG showed wave I through V potentials in ABR. By the relationship between EEG and ABR, the cases could be classified into 4 types, namely, 1) there are EEG activities with ABR showing up to wave V and the other types EEG are isoelectric with ABR findings that 2) wave V appears, 3) wave V disappears to leave wave I-III and 4) only I wave or becomes no response. The acid-base balance of the cases was inclined to acidosis; therefore, the effect of acidosis on ABR, EEG and disturbance of the brain tissue due to anoxic state wave suspected. Prognosis of DOA cases was poor and 87.2% died. All the patients who exhibited no response in ABR and isoelectric EEG at anytime of their course, died eventually. These findings suggest that combination of EEG and ABR enables one to learn more exactly the central function in those with disturbance of consciousness.

Acid-Base Equilibrium↗
PubMed1988

Identification of the dicyclohexylcarbodiimide-binding subunit of NADH-ubiquinone oxidoreductase (Complex I).

The mitochondrial NADH:ubiquinone oxidoreductase complex (Complex I) is inhibited by N,N'-dicyclohexylcarbodiimide (DCCD), and this inhibition correlates with incorporation of radioactivity from [14C]DCCD into a Complex I subunit of Mr 29,000 (Yagi, T. (1987) Biochemistry 26, 2822-2828). Resolution of [14C]DCCD-labeled Complex I in the presence of NaClO4 showed that the labeled Mr 29,000 subunit was in the hydrophobic fraction of the enzyme. This fraction, which contains greater than 17 unlike polypeptides, was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the Mr 29,000 subunit, containing bound [14C]DCCD, was isolated and purified. The amino acid composition and partial sequence of this subunit corresponded to those predicted from the mitochondrial DNA for the product of the mtDNA gene designated ND-1. The identity of the Mr 29,000 subunit with the ND-1 gene product was further confirmed by immunoblotting and immunoprecipitation experiments, using the hydrophobic fraction of [14C]DCCD-labeled Complex I and antiserum to a C-terminal undecapeptide synthesized on the basis of the human mitochondrial ND-1 nucleotide sequence. Thus, it appears that the DCCD-binding subunits of the respiratory chain Complexes I, III, and IV and in certain organisms the DCCD-binding subunit of the ATP synthase complex (Complex V) are all mtDNA products.

Amino Acid Sequence↗
PubMed1988

Purification and characterization of two types of NADH-quinone reductase from Thermus thermophilus HB-8.

Two types of the NADH-quinone reductase were isolated from Thermus thermophilus HB-8 membranes, by use of the nonionic detergent, dodecyl beta-maltoside, and NAD-agarose affinity, DEAE-cellulose, hydroxyapatite, and Superose 6 column chromatography. One of these (NADH dehydrogenase 1) is a complex composed of 10 unlike polypeptides, and the other (NADH dehydrogenase 2) exhibits a single band (Mr 53,000) upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NADH-ubiquinone-1 reductase activity of the isolated NADH dehydrogenase 1 was about 14 times higher than that of the dodecyl beta-maltoside extract and partially rotenone sensitive. The NADH-ubiquinone-1 reductase activity of the isolated NADH dehydrogenase 2 was about 30-fold as high as that of the dodecyl beta-maltoside extract and rotenone insensitive. The purified NADH dehydrogenase 1 contained noncovalently bound FMN, non-heme iron, and acid-labile sulfide. The ratio of FMN to non-heme iron to acid-labile sulfide was 1:11-12:7-9. The high content of iron and labile sulfide is suggestive of the presence of several iron-sulfur clusters. The purified NADH dehydrogenase 2 contained noncovalently bound FAD and no non-heme iron or acid-labile sulfide. The activities of both NADH dehydrogenases were stable at temperatures of greater than or equal to 80 degrees C. The occurrence of two distinct types of NADH dehydrogenase as a common feature in the membranes of various aerobic bacteria is discussed.

Cell Membrane↗
PubMed1988

The alteration in the pattern of pulmonary metastasis with adjuvant chemotherapy in osteosarcoma.

Alterations in the pattern of pulmonary metastasis of patients with osteosarcoma treated with adjuvant chemotherapy were studied. Thirty two patients who were treated with both radical surgery and adjuvant chemotherapy were observed (chemotherapy group). As a control, sixty two patients treated with radical surgery alone were also assessed (non-chemotherapy group). The chemotherapy group demonstrated a reduction in the number and a delay in the appearance of metastases. The tumour doubling time did not differ between the chemotherapy and non-chemotherapy groups. The initial site of metastasis among the chemotherapy group was most commonly in the lower lung field, whereas among the non-chemotherapy group it was usually to the middle lung field. The chemotherapy group survived longer than the non-chemotherapy group after developing pulmonary metastases. Histological examination showed that the metastatic foci stimulated the primary sites.

Adolescent↗
PubMed1988

Studies on the structure of NADH:ubiquinone oxidoreductase complex: topography of the subunits of the iron-sulfur flavoprotein component.

A catalytic component of the bovine mitochondrial NADH:ubiquinone oxidoreductase complex (Complex I) is a soluble NADH dehydrogenase iron-sulfur flavoprotein (FP). FP is composed of three subunits of Mr 51,000, 24,000, and 9,000, and contains FMN and two iron-sulfur clusters. Previous studies by others with the use of various chemical probes had suggested that, except for an access for NADH to the 51-kDa subunit, the FP polypeptides are buried within Complex I and shielded from the medium. In the present study, monospecific antibodies were raised to each of the three FP subunits, and used in conjunction with Complex I, submitochondrial particles (SMP), mitoplasts, and intact mitochondria as sources of antigens. Results of enzyme-linked immunosorbent assays and 125I-protein A labeling experiments indicated that epitopes from the 51-, 24-, and 9-kDa subunits of FP are exposed to the medium in Complex I and SMP, but not in mitoplasts and mitochondria. Appropriate enzymatic assays showed that none of the antibodies inhibited the NADH dehydrogenase activity of isolated FP or the NADH oxidase activity of SMP. These results have been discussed in relation to the structure of Neurospora Complex I deduced from membrane crystals of the isolated enzyme complex by Leonard et al. [K. Leonard, H. Haiker, and H. Weiss (1987) J. Mol. Biol. 194, 277-286].

Animals↗
PubMed1988

An improved method of electroporation for introducing biologically active foreign genes into cultured mammalian cells.

We have developed a modified, reproducible, and efficient method for introducing cloned genes into mammalian cells by using an electric field followed by treatment with sodium butyrate. Transfection frequencies with plasmid pSV2-neo, consisting of an antibiotic (G418) resistance gene and simian virus 40 (SV40) early promoter, by electroporation were higher than those by calcium phosphate DNA precipitation. Treatment with sodium butyrate following electroporation significantly increased the frequency of transfection in various types of cell lines and primary cultured cells including human skin fibroblasts. Treatment with sodium butyrate also increased the transient expression of the gene for chloramphenicol acetyltransferase (acetyl-CoA; chloramphenicol O3-acetyltransferase, CAT, EC 2.3.1.28) when the gene was introduced into BALB/c 3T3 cells by electroporation. Electroporation combined with sodium butyrate treatment is an improved method for stable and transient biochemical transformation of foreign genes in cultured mammalian cells.

Animals↗
PubMed1988

Behavior of primary horizontal canal neurons in alert and anesthetized guinea pigs.

The activities of the primary horizontal canal neurons were investigated in alert and anesthetized guinea pigs. The average resting rate in the alert guinea pigs was 47.3 +/- 21.2 spikes/s. This value was significantly higher than that in anesthetized animals which had an average rate of 39.1 +/- 20.5 spikes/s. The average gain from the total of 66 units tested at 0.3-Hz sinusoidal rotation was 0.42 +/- 0.37 spikes/s/degree/s, and this value was the same as that of anesthetized guinea pigs. The average phase lag to the angular acceleration was 57.3 +/- 20.7 degrees in the alert guinea pigs, which was significantly smaller than that in the anesthetized animals. The number of cutoff neurons at 0.3 Hz was 1 out of 67 neurons in the alert guinea pigs and 7 out of 64 neurons in the anesthetized guinea pigs. The functional meaning of these differences in primary semicircular canal neurons is discussed.

Action Potentials↗
PubMed1988

A simple purification method for a glucosyltransferase complex from Streptococcus mutans OMZ 176 with a high yield.

1. Glucosyltransferase was purified from Streptococcus mutans OMZ 176 by ammonium sulfate fractionation and gel filtration. 2. The overall purification was about 15,000-fold with a yield of 53%. 3. The purified enzyme appeared to be a multienzyme complex consisting of three different components with molecular weights of 158,000, 153,000 and 149,000, respectively.

Ammonium Sulfate↗
PubMed1988

Characterization and complete amino acid sequence of ferredoxin II from Desulfovibrio vulgaris Miyazaki.

One of 2 ferredoxins, Fd II, purified from Desulfovibrio vulgaris Miyazaki (DvM) has been characterized and its complete amino acid sequence established. Fd II is composed of 63 amino acid residues and contains 7 cysteinyl residues but has only 4 iron atoms in an iron-sulfur cluster of a standard redox potential of -405 mV. The arrangement of cysteinyl residues in the protein suggests that some cysteinyl residues are not directly involved in ligation to the iron-sulfur cluster. Homology is recognized among Fd II (DvM), Fd I (D. desulfuricans Norway), Fd I (D. africanus Benghazi), and Fd (D. gigas). Although Fd I and Fd II in DvM are poorly homologous, the C-terminal half of Fd I is fairly homologous to the N-terminal half of Fd II. Fd II is 40% as effective as Fd I as an electron carrier for pyruvate dehydrogenase coupled with hydrogenase and cytochrome c3.

Amino Acid Sequence↗
PubMed1988

Determination of human aspartate aminotransferase isoenzymes by their differential sensitivity to proteases.

The effect of various proteases (trypsin, chymotrypsin, subtilisin, protease 401, and thermolysin) on the mitochondrial isoenzyme (m-AST) and cytoplasmic isoenzyme (c-AST) of human and swine aspartate aminotransferase (AST;EC 2.6.1.1) was evaluated. All procedures including the reaction with proteases and the subsequent determination of the AST activity were carried out in an automatic analyzer. The mammalian c-AST was efficiently inactivated by chymotrypsin, subtilisin and protease 401 while m-AST activity decreased very slowly with these proteases. Thermolysin and trypsin showed much less effect on c-AST activity. Especially, chymotrypsin at concentrations of 0.5-1.0 g/L inactivated human c-AST almost completely but showed no detectable inactivating effect on m-AST. Thus chymotrypsin appears to be the most suitable protease for the differential determination of AST isoenzymes in human serum. Further studies on the effects of proteases with AST from other species showed that Escherichia coli AST resembled mammalian m-AST while Pseudomonas AST resembled c-AST.

Animals↗
PubMed1988

Purification and characterization of ferredoxin from Desulfovibrio vulgaris Miyazaki.

Two ferredoxins, Fd I and Fd II, were isolated and purified from Desulfovibrio vulgaris Miyazaki. The major component, Fd I, is an iron-sulfur protein of Mr 12,000, composed of two identical subunits. The absorption spectra of Fd I and Fd II have a broad absorption shoulder near 400 nm characteristic of iron-sulfur proteins. The purity index, A400/A280, of Fd I is 0.69, and its millimolar absorption coefficient at 400 nm is 3.73 per Fe. It contains two redox centers with discrete redox behaviors. The amino acid composition and the N-terminal sequence of Fd I are similar to those of Fd III of Desulfovibrio africanus Benghazi and Fd II of Desulfovibrio desulfuricans Norway. Fd I does not serve as an electron carrier for the hydrogenase of D. vulgaris Miyazaki, but it serves as a carrier for pyruvate dehydrogenase of this bacterium. The evolution of H2 from pyruvate was observed by a reconstructed system containing purified hydrogenase, cytochrome C3, Fd I, partially purified pyruvate dehydrogenase, and CoA. The H2-sulfite reducing system can be reconstructed from the purified hydrogenase, cytochrome C3, Fd I and desulfoviridin (sulfite reductase), but the reaction rate is very slow compared to that of the crude extract at the same molar ratio of the components.

Amino Acid Sequence↗
PubMed1988

Amino acid sequence of ferredoxin I from Desulfovibrio vulgaris Miyazaki.

The amino acid sequence of ferredoxin (Fd) I, purified from Desulfovibrio vulgaris Miyazaki, has been established. Fd I is strikingly similar to Fd III of D. africanus Benghazi with 84% homology. Both have the sequence, -Cys-x-x-Asp-x-x-Cys-x-x-x-Cys-Pro- in the N-terminal half, and the sequence, -Cys-x-x-Cys-x-x-Cys-x-x-x-Cys-Glu- in the C-terminal half of the molecule, instead of the common sequences for ligation to the usual [4Fe-4S] clusters. Fd I has 76% homology to Fd II of D. desulfuricans Norway.

Amino Acid Sequence↗
PubMed1988

Interaction of cellular hydrogenase, cytochrome c3, and desulfoviridin in Desulfovibrio vulgaris Miyazaki with their antibodies.

Anti-sera for hydrogenase, cytochrome c3, and desulfoviridin (abbreviated as anti-hyd, anti-c3, and anti-dvn, respectively) were raised in mice, and used to locate these antigens in cells of Desulfovibrio vulgaris Miyazaki. The activity of the intact cells to absorb H2 with methyl viologen or sulfite as an electron acceptor was cumulatively inhibited by treating the cells with anti-hyd and anti-c3 but unaffected by anti-dvn treatment. The activity of the intact cells to produce H2 from formate was also inhibited by anti-c3 treatment, but the inhibition by anti-hyd treatment was not significant. The fluorescent antibody technique applied to intact cells of D. vulgaris Miyazaki indicated that both hydrogenase and cytochrome c3 are localized on the surface of the cell. These results are not exactly in conformity with the hydrogen-cycling hypothesis for proton gradient formation in the energy metabolism in Desulfovibrio. The procedure described in the present paper provides a new technique to elucidate the roles of proteins by applying anti-sera to intact cells without destroying the cellular structure.

Antibody Formation↗
PubMed1988

High-grade surface osteosarcoma of the left ilium. A case report and review of the literature.

A rare case of high-grade surface osteosarcoma of the left ilium is reported. Trephine biopsy performed on a 31-year-old woman suffering from a huge tumor of the left buttock revealed high-grade osteosarcoma, and hemipelvectomy was undertaken. The surgical specimen showed that the tumor was present on the surface of the left ilium. Ten months after the operation, the patient died of brain metastasis. From these results, we considered this case to be one of high-grade surface osteosarcoma.

Adult↗