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Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 793 records · Page 44Linked to original sources
PubMed1992

New hydroxybenanomicins produced by Actinomadura.

A soil microorganism, Actinomadura sp. MH193-16F4, produces an antifungal antibiotic benanomicin A and several related compounds. Among them, benanomicin A is the best candidate as a chemotherapeutic agent in terms of antifungal activity, toxicity and water-solubility. Three novel hydroxyl congeners, 3'-hydroxybenanomicin A, 7-hydroxybenanomicin A and 7-hydroxybenanomicinone have been isolated from the culture broth of the MH193-16F4 strain or its mutant. Interestingly, 3'-hydroxy-benanomicin A was as effective as benanomicin A, but the 7-hydroxy congeners were inactive. The inactive congeners differ from benanomicin A and 3'-hydroxyenanomicin A in their conformational structures at C-5 and C-6.

Anthracyclines↗
PubMed1992

Cholangiocellular carcinoma in the caudate lobe with intraluminal growth in the extrahepatic bile duct.

A case of cholangiocellular carcinoma in the caudate lobe with intraluminal growth in the extrahepatic bile duct is reported. The main tumor in the caudate lobe was detected by computed tomography and angiography, and two intraluminal tumors at the hepatic hilus and at the root of the right posterior segmental duct were well demonstrated by cholangiography and percutaneous transhepatic cholangioscopy. Independent total caudate lobectomy with bile duct resection was performed. Cholangiocellular carcinoma of the liver with intraluminal growth in the extrahepatic bile duct is very rare and has not been reported in the literature. Independent caudate lobe resection requires a rather complicated technique. However, this method has the advantage of reducing to a minimum the hepatic volume to be resected, and is useful for poor-risk patients or for cases with localized carcinoma at the hepatic hilus.

Adenocarcinoma↗
PubMed1992

[A case of intrahepatic cholesterol stone complicated with atrophy of the anterior superior ventral and anterior superior lateral subsegments (S8ab) of the liver].

A 61-year-old male patient with intrahepatic cholesterol stone is reported. Stones were detected in the anterior superior lateral subsegment (S8ab) of the right lobe with bile duct stenosis, the lateral anterior segment (S3) of the left lobe, and the left caudate lobe (S11). Partial hepatectomy including S8ab, S3 and S11 was performed to remove all stones. Atrophy of S8ab was diagnosed by CT, and PTP clarified the patency of the subsegmental portal vein (P8ab). This is a rare case with cholesterol intrahepatic stone with regional bile duct stenosis and subsegmental atrophy of S8ab of the liver.

Atrophy↗
PubMed1991

Aspartic acid 349 in the fourth epidermal growth factor-like structure of human thrombomodulin plays a role in its Ca(2+)-mediated binding to protein C.

The last three consecutive epidermal growth factor (EGF)-like structures of human thrombomodulin constitute the functional domain for protein C-activating cofactor activity and anticoagulant activity. Using site-directed deletion mutagenesis, we found that amino acid Asp349 of TME456, a recombinantly produced protein consisting of EGF-like structures 4, 5, and 6, is essential for retaining full protein C-activating cofactor activity. To investigate the role of Asp349 in the protein C-activating cofactor activity of human thrombomodulin, we have constructed two mutants of TMD123, a recombinantly produced protein consisting of domains D1, D2, and D3 of thrombomodulin, using site-directed point mutagenesis of the thrombomodulin coding sequence. In mutant TMD123A, the Asp349 codon was replaced with an Ala codon and in mutant TMD123E, the Asp349 codon was replaced with a Glu codon. The partially purified mutant proteins were assayed for their protein C-activating cofactor activity at various Ca2+ concentrations. TMD123 and TMD123E protein showed similar high levels of cofactor activity and similar patterns of Ca2+ dependence, while TMD123A had lower cofactor activity and did not show any Ca2+ dependence. We concluded that Asp349 in the fourth EGF-like structure of human thrombomodulin plays a role in its Ca(2+)-mediated binding to protein C.

Amino Acid Sequence↗
PubMed1991

Chemical structure of the carbohydrate backbone of Vibrio parahaemolyticus serotype 012 lipopolysaccharide.

The chemical structure of the saccharide portion of Vibrio parahaemolyticus serotype 012 lipopolysaccharide was studied. Using chemical degradation and modification, as well as methylation analysis in combination with GLC-MS, laser-desorption mass spectrometry and 1H-NMR and 13C-NMR spectroscopy, the carbohydrate backbone of the lipopolysaccharide was characterized as a branched decasaccharide with the following structure: (formula; see text) In the native lipopolysaccharide two additional phosphate groups are present and 3-deoxy-D-threo-hexulosonic acid and D-galacturonic acid are bound via acid-labile linkages.

Carbohydrate Conformation↗
PubMed1991

Various hippocampal lesions induced by multi-fractional ibotenic acid injections and amygdala kindling in rats.

Hippocampal degenerative lesions were made bilaterally by means of multiple ibotenic acid injections and development of amygdala kindling was studied. In groups with lesions in either bilateral dorsal or ventral hippocampus, stimulations required for kindling were almost the same as those of controls. In the group with lesion of the entire hippocampus, kindling development was remarkably slow especially in the early stage of the kindling process. However, kindling effect was finally established in all groups.

Amygdala↗
PubMed1991

Isolation of estrogen receptor-binding sites in human genomic DNA.

Total genomic DNA digested by restriction enzymes was mixed with the DNA-binding domain of the estrogen receptor (ER-DBD) that was expressed in Escherichia coli and the fragments that bound to it were selected by nitrocellulose filter. These fragments were cloned into a plasmid vector and amplified. This selection process was repeated six times and five fragments ranging from 0.2 to 2 kb were isolated. Interestingly, each of these fragments had a perfect palindromic estrogen responsive element (ERE) (GGT-CANNNTGACC). More surprisingly, one of the fragments was found to be derived from the same locus as a fragment obtained by another similar but independent experiment. The results indicate that the ER-DBD region can bind by itself specifically to the perfect palindromic ERE with a 3 base pair spacing but it does not bind strongly enough to the half palindromic EREs or to the imperfect palindromic EREs. Chloramphenicol acetyltransferase assay has shown that some of these fragments have estrogen-dependent enhancer activity, suggesting the existence of a target gene near these fragments. The method described here may be generally applicable for screening and isolation of other transcription factor-binding sites in genomic DNA.

Amino Acid Sequence↗
PubMed1991

Autoprocessing of Drosophila copia gag precursor to generate a unique laminate structure in Escherichia coli.

Drosophila copia protease is likely to be encoded in the gag gene. We have expressed copia gag polyprotein precursor in E. coli. The gag precursor was correctly processed to generate a unique laminate structure in E. coli. The processing was almost completely blocked by a mutation at the putative active site of copia protease, and resulted in accumulation of the precursor. Furthermore, the laminate structure was not found in E. coli expressing the mutant precursor. These results indicate that the protease is involved in cleaving the gag precursor itself. Also, the assembly of copia gag protein should correlate to the autoprocessing of copia gag polyprotein precursor.

Animals↗
PubMed1991

Protein kinase C and Ca2+/calmodulin-dependent protein kinase II phosphorylate a novel 58-kDa protein in synaptic vesicles.

A monoclonal antibody was made using the spleen cells of a mouse immunized with chick synaptic membranes and designated as mAb 1D12. It immunoprecipitated 25% of the omega-conotoxin binding protein but no dihydropyridine binding protein solubilized from chick brain membranes. By immunoblotting, a polypeptide of 58-kDa was identified as the antigen of this antibody in chick, rat, rabbit and guinea pig brain. Immunohistochemical observation indicated the immunoreactivity of mAb 1D12 to be localized in the synaptic regions of central and peripheral neurons. In peripheral organs, there was additional staining in the distal portions of nerve fibers. Immunoelectron microscopy showed immunoreactivity to be located in synaptic vesicle and presynaptic plasma membranes. In the subcellular fractionation of rat brain, 58-kDa protein was recovered in the fractions of synaptic vesicles and plasma membranes but not soluble proteins. This protein could be extracted from membranes by Triton X-100 but treatment with EDTA, acid, base or high salt failed to have such effect. Solubilized 58-kDa protein of rat brain was purified by immunoaffinity chromatography using mAb 1D12. Both protein kinase C and Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) phosphorylated purified 58-kDa protein, and maxima of 0.47 and 0.94 mol of phosphates, respectively, were incorporated per mol of 58-kDa protein. 58-kDa protein was not phosphorylated by either cAMP-dependent or cGMP-dependent protein kinase. When present in membranes, it was also phosphorylated by protein kinase C and CaM kinase II. Possible involvement of 58-kDa protein in the protein kinase C and CaM kinase II-mediated regulation of synaptic transmission in central and peripheral neurons is discussed.

Animals↗
PubMed1991

Combined portal vein and liver resection for carcinoma of the biliary tract.

Twenty-nine patients with advanced carcinoma of the bile duct or gallbladder underwent combined portal vein and liver resection. Segmental excision of the portal vein was performed in 16 cases and wedge resection of the vessel wall in 13. The operative mortality rate was 17 per cent. The median survival for the 24 patients who left hospital was 19.8 months. Actuarial survival rates at 1, 3 and 5 years for all 29 patients were 48 per cent, 29 per cent, and 6 per cent respectively, whereas the median survival for 46 patients with unresectable carcinoma was 3 months and the 1 and 3-year actuarial survival rates were 13 per cent and zero respectively. This difference in survival times between patients undergoing hepatectomy with portal vein resection and those with unresectable carcinoma were statistically significant (P less than 0.01). Combined portal vein and liver resection is recommended as a reasonable surgical approach in selected patients with advanced carcinoma of the biliary tract.

Adult↗
PubMed1991

New degradation product of des-Gly10-NH2-LH-RH-ethylamide (fertirelin) in aqueous solution.

A new degradation product was found in an ampule preparation of des-Gly10-NH2-LH-RH-ethylamide (fertirelin) stored at room temperatures. The same product, produced at a higher temperature, was identified to be a diastereomeric mixture of cyclo(His-Trp) by proton nuclear magnetic resonance spectroscopy, mass spectrometry, and comparison with authentic samples. Preferred conformations regarding substituents on the diketopiperazine ring of cyclo(His-Trp) were calculated using coupling constants between vicinal protons.

Amino Acid Sequence↗