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Biomedical subjects

J Kondo

Publications and source records attributed to J Kondo.

At least 19 recordsLinked to original sources
PubMed1992

Peroxisomal acetoacetyl-CoA thiolase of an n-alkane-utilizing yeast, Candida tropicalis.

Two genes encoding acetoacetyl-CoA thiolase (thiolase I; EC 2.3.1.9), whose localization in peroxisomes was first found with an n-alkane-utilizing yeast, Candida tropicalis, were isolated from the lambda EMBL3 genomic DNA library prepared from the yeast genomic DNA. Nucleotide sequence analysis revealed that both genes contained open reading frames of 1209 bp corresponding to 403 amino acid residues with methionine at the N-terminus, which were named as thiolase IA and thiolase IB. The calculated molecular masses were 41,898 Da for thiolase IA and 41,930 Da for thiolase IB. These values were in good agreement with the subunit mass of the enzyme purified from yeast peroxisomes (41 kDa). There was an extremely high similarity between these two genes (96% of nucleotides in the coding regions and 98% of amino acids deduced). From the amino acid sequence analysis of the purified peroxisomal enzyme, it was shown that thiolase IA and thiolase IB were expressed in peroxisomes at an almost equal level. Both showed similarity to other thiolases, especially to Saccharomyces uvarum cytosolic acetoacetyl-CoA thiolase (65% amino acids of thiolase IA and 64% of thiolase IB were identical with this thiolase). Considering the evolution of thiolases, the C. tropicalis thiolases and S. uvarum cytosolic acetoacetyl-CoA thiolase are supposed to have a common origin. It was noticeable that the carboxyl-terminal regions of thiolases IA and IB contained a putative peroxisomal targeting signal, -Ala-Lys-Leu-COOH, unlike those of other thiolases reported hitherto.

Acetyl-CoA C-Acetyltransferase↗
PubMed1992

Enalapril reduces the enhanced 1,2-diacylglycerol content and RNA synthesis in spontaneously hypertensive rat hearts before established hypertension.

There is evidence that cardiac hypertrophy in spontaneously hypertensive rats (SHR) occurs before the development of hypertension. 1,2-Diacylglycerol, which is thought to be a second messenger activating protein kinase C, is also produced in excess in SHR hearts at 4 weeks of age, before established hypertension. We determined myocardial 1,2-diacylglycerol content in SHR with and without prazosin and enalapril from 3 to 4 weeks of age. Hearts from untreated SHR had greater RNA and DNA synthesis and greater relative weights at 4 weeks of age than those from Wistar-Kyoto (WKY) rats. There was no difference in triglyceride content or phospholipid species between WKY rats and untreated SHR, except for a higher cholesterol content in SHR. Treatment of SHR with enalapril, but not prazosin, lowered not only 1,2-diacylglycerol content but also RNA synthesis to the levels of WKY rats. Moreover, fatty acids involved in 1,2-diacylglycerol were altered by enalapril despite the lack of a difference between WKY rats and untreated SHR. Prazosin did not have any effect on 1,2-diacylglycerol fatty acid composition. Enalapril may decrease cardiac hypertrophy in SHR by lowering myocardial 1,2-diacylglycerol production.

Animals↗
PubMed1992

Identification of novel blood proteins specific for mammalian hibernation.

Mammalian hibernation is a unique physiological adaptation that allows the sustainment of life under extremely low body temperatures. In the chipmunk, we found four proteins related specifically to hibernation. These proteins started to diminish in concentration in the blood before and disappeared during hibernation. These proteins reappeared in the blood as hibernation ceased and remained during nonhibernation. The complete or partial amino acid sequences of the four proteins showed that three (27-, 25-, and 20-kDa) were previously unknown, whereas another (55-kDa) is highly homologous with alpha 1-antitrypsin. The three novel proteins are homologous, indicating that they are a family. In the NH2-terminal regions of these proteins, a collagen-like amino acid sequence is present, whereas in their COOH-terminal regions, two sequences, Ser-Ala-Phe-Ala-Val-Lys and Val-Trp-Leu-Glu, are conserved. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions and gel permeation chromatography under denaturating conditions revealed that the four proteins form a 140-kDa complex in the plasma fraction. The novel proteins were detected in blood of another hibernator, the ground squirrel, but not in rodent nonhibernators, namely tree squirrels and rats. The present finding is the first identification of a hibernation-specific protein. The presence of specific proteins in hibernators suggests the involvement of genetic factors in the control of hibernation. These proteins provide valuable tools for understanding molecular mechanisms of mammalian hibernation.

Amino Acid Sequence↗
PubMed1992

A novel protease obtained from FBS-containing culture supernatant, that processes single chain form hepatocyte growth factor to two chain form in serum-free culture.

The recombinant human hepatocyte growth factor (r-hHGF) produced by Chinese hamster ovary cells transfected with hHGF cDNA (CHO BD-24 cells) was the two chain form in fetal bovine serum (FBS) containing culture. However, in serum-free culture the non-processed r-hHGF, single chain form, was detected with two chain form r-hHGF. We purified the protease that proteolytically processed single chain r-hHGF to two chain form r-hHGF. A protease was purified to give a single peak from the culture supernatant by use of several column chromatographies. When this protease was added to serum-free culture of CHO BD-24 cells, the proteolytic processing of single chain r-hHGF to two chain form r-hHGF was completely achieved. This protease was found to be composed of two peptide chains with molecular mass of 38 kDa under non-reducing condition by SDS-PAGE. The results of N-terminal amino acid sequence analysis and inhibitor selectivity suggested that this protease was a novel serine protease originating from fetal bovine serum.

Amino Acid Sequence↗
PubMed1992

Changes in ventricular 1,2-diacylglycerol content in rats following monocrotaline treatment.

OBJECTIVE: 1,2-Diacylglycerol may initiate cardiac hypertrophy, probably by activating protein kinase C. To test this hypothesis we determined the 1,2-diacylglycerol content of hypertrophied tissue. METHODS: Rats were treated with monocrotaline and developed severe right ventricular hypertrophy followed by congestive heart failure. 1,2-Diacylglycerol content and fatty acid composition, DNA concentrations, and RNA concentrations in the right ventricle from monocrotaline treated rats were compared with values obtained from the left side or from control rats. RESULTS: During the first week, the right ventricle showed no significant change in 1,2-diacylglycerol content and a small increase in RNA concentration. However, the 1,2-diacylglycerol content was significantly increased by 55% at two weeks after monocrotaline injection, when DNA and RNA synthesis was also enhanced to its highest level when compared with control rats (37% and 18%, respectively). At four weeks after monocrotaline injection, conversely, the 1,2-diacylglycerol content was decreased by 25% in the right ventricle from monocrotaline treated rats, most of which had pleural and peritoneal effusions indicating congestive heart failure, although RNA synthesis was sustained at a high level. The fatty acid composition of 1,2-diacylglycerol did not differ significantly between the right and left ventricles or control rat ventricles. CONCLUSIONS: These results suggest that 1,2-diacylglycerol accumulation is associated with development of hypertrophy in monocrotaline treated rats. In contrast, at a stage of congestive heart failure 1,2-diacylglycerol production decreased, suggesting that intracellular transduction mechanisms may be attenuated.

Animals↗
PubMed1992

A case of idiopathic retroperitoneal fibrosis with chronic pericarditis.

A 66-year-old male with chronic pericarditis accompanied by idiopathic retroperitoneal fibrosis was originally admitted for cardiac tamponade. A firm diagnosis was obtained only after the patient's sudden death when autopsy was performed. Chest X-rays showed cardiac enlargement and pleural effusion. Echocardiogram revealed bright echo density on the myocardium.

Aged↗
PubMed1992

[Pulmonary arteriovenous malformation with systemic blood supply].

A forty-eight year-old woman who had suffered from exertional dyspnea and cyanosis since her youth was found to have abnormal shadow in her right lower lung at the roentgenographic examination. Pulmonary angiography showed cavernous network between pulmonary artery and vein of the 8th, 9th, and 10th segments. Bronchial artery was dilated, supplying the cavernous lesion. From these findings this lesion was diagnosed as pulmonary arteriovenous malformation feeded by bronchial artery. Right lower lobectomy was performed. The effect of resection was confirmed by intraoperative arterial gas analysis before and after the excision. She has been doing well without any signs of recurrence for 3 years after the surgery.

Arteries↗
PubMed1992

[Comparison of long-term outcome of closed mitral commissurotomy (CMC) versus open mitral commissurotomy (OMC) and mitral valve replacement (MVR)].

To predict the late result of percutaneous mitral balloon valvotomy (PMV), we studied long term outcome of CMC which is similar to PMV in terms of closed heart technic, comparing with those of OMC and MVR. 226 patients with mitral stenosis were studied. 117 patients had CMC, 72 had OMC and 37 had MVR. The cumulative follow up period in these groups were 1892 patient year, 632 patient year and 200 patient year respectively. Postoperative actual survival rate at 5, 10, 15 years in CMC patients were 95 +/- 2%, 91 +/- 3%, 86 +/- 3% respectively. No operative or late death was seen in OMC or MVR patients. Postoperative event free rate at 10 years in OMC or MVR patients (97 +/- 2%, 90 +/- 6%, respectively) were higher than that in CMC patients (79 +/- 4%). Thromboembolism developed in 7 (6%) CMC patients, and 4 of these patients died from cerebral embolism. No patient in OMC or MVR group had thromboembolism. Reoperation was done for mitral restenosis or regurgitation in 40 CMC patients. 15 (38%) of these patients were associated with pulmonary hypertension, and 22 (55%) patients had secondary tricuspid regurgitation. On the other hand, only 1 OMC patient and 1 MVR patient had reoperation due to restenosis or thrombosed artificial valve. These results suggest that PMV should be indicated for restricted cases of mitral stenosis.

Adult↗
PubMed1992

[Two cases of acute myocardial infarction with simultaneous occlusions of two main branches].

Acute myocardial infarction with simultaneous occlusions of two main branches is very rare, and it is difficult to presume it before performing emergent CAG. We encountered two such cases recently. Case 1 was a 77 year-old woman. She was admitted to our hospital because of anterior chest pain. Emergent CAG disclosed complete occlusions of RCA-Segment 3 and LAD-Segment 7. ICT improved both of them to 90% stenoses. Case 2 was a 58 year-old man. He was admitted to our hospital because of upper abdominal pain. Emergent CAG disclosed complete occlusions of RCA-Segment 2 and LAD-Segment 6. ICT improved the former to 99% stenosis, and the latter recanalized. Myocardial dual scintigrams performed during the acute periods showed findings which were consistent with simultaneous occlusion of the two main branches in both cases. We could consider such reasons as coronary vasospasm, state of hyper-coagulability at the onset of myocardial infarction and depression of coronary pressure etc as possible causes of these cases.

Aged↗
PubMed1992

[Recurrent thromboses of the Björk-Shiley valve in a patient with gout].

A 56-year-old male, who had mitral stenosis and gout, underwent mitral valve replacement with the Björk-Shiley valve prosthesis. Four years after the surgery, the patient suddenly became dyspneic on exercise due to malfunctioning valve. Thrombosis was found on the prosthesis, which was replaced again by Björk-Shiley valve. Thrombotest value had been satisfactorily controlled at 12.8 +/- 4.2% with warfarin since the first surgery. Dilazep chlorate also had been prescribed. Hyperuricemia had been controlled with allopurinol. In spite of these combined medical therapy, thrombosed valve recurred. Clotted prosthesis was superseded by Carpentier-Edwards Bioprosthesis. Enhancement of platelet function of the patients with gout and hyperuricemia has been reported. Gout in this case might have influence on the recurrent episodes of thrombosis. Monitoring of platelet function would be necessary in follow-up of a patients with gout and valve replacement.

Equipment Failure↗
PubMed1991

Molecular cloning of a porcine gene syk that encodes a 72-kDa protein-tyrosine kinase showing high susceptibility to proteolysis.

By using antibodies raised against a portion of N terminus of 40-kDa kinase (Kobayashi, T., Nakamura, S., Taniguchi, T., and Yamamura, H. (1990) Eur. J. Biochem. 188, 535-540), not only 40-kDa protein but also 72-kDa protein were detected on immunoblot analysis of porcine spleen homogenate. In splenocytes preparation, the antibodies could immunoprecipitate protein-tyrosine kinase activity of the 72-kDa protein but not detect the 40-kDa protein even on immunoblot. After incubation of crude spleen homogenate at 37 degrees C with or without various protease inhibitors, immunoblot analysis revealed proteolytic breakdown of the 72-kDa protein to 40-kDa fragment. Next, using oligonucleotides designed according to partially sequenced information of the 40-kDa kinase as a probe, we have isolated a clone containing entire coding sequence for the 40-kDa kinase from a porcine spleen cDNA library. This clone had a 1884-base-pair-long open reading frame encoding 628-amino-acid polypeptide with a calculated molecular weight of 71,618. The deduced amino acid sequence did not contain a ligand binding or membrane spanning region but did a well-conserved protein-tyrosine kinase domain and two src homology region 2 domains. The sequences of these domains showed 30-40% identity to those of other protein-tyrosine kinases, but those of remaining parts were quite unique. From these results, we concluded that the 40-kDa kinase was generated by proteolysis from the 72-kDa holoprotein which was a new member of nonreceptor protein-tyrosine kinase so far reported. We therefore designated this gene as syk after spleen tyrosine kinase.

Amino Acid Sequence↗
PubMed1991

Molecular cloning of a new class of cartilage-specific matrix, chondromodulin-I, which stimulates growth of cultured chondrocytes.

Here we report the structure and bioactivity of 25 kDa glycoprotein (chondromodulin-I) as a tissue-specific functional matrix component identified and cloned for the first time. Chondromodulin-I purified from fetal bovine cartilage markedly stimulated DNA synthesis of cultured growth-plate chondrocytes in the presence of basic fibroblast growth factor (FGF). Bovine chondromodulin-I cDNA revealed that the mature protein consists of 121 amino acids with three possible glycosylation sites and is coded as the C-terminal part of a larger precursor. On northern blot analysis, expression of chondromodulin-I mRNA was observed only in cartilage.

Amino Acid Sequence↗
PubMed1991

Identification of the N-terminal residue of the heavy chain of both native and recombinant human hepatocyte growth factor.

The N-terminal amino acid of the heavy chain of native (purified from human plasma) and recombinant human hepatocyte growth factor (hHGF) was determined by analyses of amino acid composition and sequence of peptide fragments derived by enzymatic cleavage, peptide mapping, and fast atom bombardment mass spectrometry. Our results indicate that the N-terminal amino acid of the heavy chain of hHGF, both native and recombinant, is pyroglutamate, derived from glutamine at the 32nd residue from the initiation methionine.

Amino Acid Sequence↗
PubMed1991

High level expression of isocitrate lyase gene of n-alkane-utilizing yeast Candida tropicalis in Saccharomyces cerevisiae.

The genomic DNA of peroxisomal isocitrate lyase (ICL) isolated from an n-alkane-assimilating yeast, Candida tropicalis, was truncated to utilize the original open reading frame under the control of the GAL7 promoter and was expressed in Saccharomyces cerevisiae. The recombinant ICL was synthesized as a functionally active enzyme with a specific activity similar to the enzyme purified from C. tropicalis, and was accounted for approximately 30% of the total extractable proteins in the yeast cells. This recombinant enzyme was easily purified to homogeneity. N-Terminal amino acid sequence, molecular masses of native form and subunit, amino acid composition, peptide maps, and kinetic parameters of the recombinant ICL were essentially the same as those of ICL purified from C. tropicalis. From these facts, S. cerevisiae was suggested to be an excellent micro-organism to highly express the genes encoding peroxisomal proteins of C. tropicalis.

Amino Acid Sequence↗
PubMed1991

Suppression of the degradation of recombinant human apolipoprotein E by a protease inhibitor obtained from fetal bovine serum in serum-free culture.

The recombinant human apolipoprotein E (Apo-E) produced by Chinese hamster ovary cells (CHO-322 cells) in serum free culture was degraded to 24K and 23K fragments that contained N-terminal amino acid. The degradation site of Apo-E to 24K fragment was between Arg180 and Leu181 and the C-terminal amino acid of 23K fragment was Gly169. In fetal bovine serum (FBS)-containing culture, the degradation was inhibited. However, in calf serum (CS) the inhibitory activity was not detected. Thus, we attempted the purification of the factor with this inhibitory activity from FBS. A protease inhibitor was purified to give a single peak from FBS by ammonium sulfate precipitation and combination of several column chromatographies. When this FBS-derived protease inhibitor (FBS-d-PI) was added to serum-free culture of CHO-322 cells, degradation of recombinant Apo-E to the 24K and 23K fragments was dose-dependently suppressed and accumulation of intact Apo-E in culture supernatant was observed. FBS-d-PI was found to be a glycoprotein with relative molecular size of 75K daltons under reducing condition, and 85K daltons under nonreducing condition by SDS-PAGE. A complex of FBS-d-PI and a cellular protease was also detected in culture supernatant by western blot analysis using mouse monoclonal antibodies against FBS-d-PI.

Amino Acid Sequence↗
PubMed1991

Isolation and characterization of Japanese eel prolactins.

A highly purified prolactin (PRL) was isolated from the pituitary of the Japanese eel (Anguilla japonica) by extraction with acid-acetone, gel filtration on Sephadex G-75, and reversed-phase HPLC on TSK-gel ODS 120T and on TSK-gel TMS 250. Eel PRL is comprised of two variants (ePRL I and II), which were separated by HPLC on an ODS column. The two PRLs were also secreted by organ-cultured pituitaries in a defined medium. After being dialyzed against distilled water and lyophilized, the medium was dissolved in 0.01 M ammonium acetate (pH 9.0), and then the insoluble fraction was subjected to HPLC on an ODS column to isolate the secreted PRLs. The ePRL I and II were equipotent in retaining plasma Na in the hypophysectomized killifish, Fundulus heteroclitus, transferred from sea-water to fresh water. The putative PRL-producing cells in the rostral pars distalis of the eel pituitary were specifically stained with the antiserum against the mixture of ePRL I and II. Both PRLs had a molecular weight of 22 kDa in SDS-PAGE, an isoelectric point of 10.1 by gel electrofocusing, and an N-terminal residue of valine. Amino acid compositions and the partial amino acid sequences of ePRL I and II show that they are highly homologous with a limited number of substitutions, and that they are more closely related to those of teleostean PRLs than to those of mammalian PRLs.

Amino Acid Sequence↗
PubMed1991

Decreased 1,2-diacylglycerol levels in myopathic hamster hearts during the development of heart failure.

1,2-Diacylglycerol is believed to play an important role in cellular functions through protein kinase C activation, although its role in cardiac functions remains largely unexplored. We determined the level of 1,2-diacylglycerol and its fatty acid composition in heart tissues from Syrian hamsters with hereditary cardiomyopathy (BIO 14.6 strain) during the development of congestive heart failure from 90 days to 240 days of age. The myopathic hamsters had lower contents of triglyceride and of the major phospholipids, phosphatidylcholine, phosphatidylethanolamine and cardiolipin, in the myocardium when compared to normal hamsters, whereas there was no difference in the cholesterol content. No difference in the myocardial 1,2-diacylglycerol content was observed at 90 days of age. On the other hand, 1,2-diacylglycerol contents in myopathic hearts at 160 and 240 days of age were significantly lower by 21% and 52%, respectively, then in age-matched normal hamsters. The oldest hamsters (240-day-old) showed reduced 1,2-diacylglycerol levels in both groups despite an age-related increase in most lipids. The 1,2-diacylglycerol fatty acid composition profile was found to be different from that of other lipids, and there were several differences in the fatty acid composition of 1,2-diacylglycerol between the two groups at 240 days of age. These results indicate that decreased levels of 1,2-diacylglycerol occur concomitantly with congestive heart failure in the myopathic hamsters.

Animals↗