Search PubMed⌕ Search

Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 775 records · Page 43Linked to original sources
PubMed1992

Preparation of 13C and 15N labeled bellenamine and its degradation products.

A streptomyces metabolite, bellenamine, has been converted into D-beta-lysinamide and cyclized bellenamine in an acidic solution at 75 degrees C. The structure of the new cyclized compound was assigned as (R)-6-(3-aminopropyl)-1,3-diazacyclohexan-4-one by spectral analyses. [1-13C, Amide, 1'-15N2]bellenamine, which has been isolated from the culture by feeding both L-[1-13C]lysine and [15NH4]2SO4 to a synthetic medium, was degraded under acidic condition to obtain the stable isotope labeled D-beta-lysine, D-beta-lysinamide and cyclized bellenamine. These labeled compounds were analyzed by 13C and 15N NMR spectra, and will be used for the biosynthetic study on bellenamine.

Ammonium Sulfate↗
PubMed1992

Synthesis and activity of 3-(isoxazolin-5-yl)- and 3-(isoxazol-4-yl)cephalosporins.

The 1,3-dipolar cycloaddition of nitrile oxide with 3-vinylcephalosporin provided diastereomeric isomers of 3-(isoxazolin-5-yl)cephalosporin. Cycloaddition of nitrile oxide with 3-(dimethylamino-vinyl)cephalosporin gave 3-(isoxazol-4-yl)cephalosporin. These semisynthetic cephalosporins with an aminothiazole in the C-7 side chain showed moderate antibacterial activities.

Anti-Bacterial Agents↗
PubMed1992

Synthesis and activity of potent 3-(isoxazolidin-5-yl)- and 3-(isoxazolidinium-5-yl)cephalosporins.

The syntheses and in vitro antibacterial activities of 3-(isoxazolidin-5-yl)- and 3-(isoxazolidinium-5-yl)cephalosporins are described. 1,3-Dipolar cycloaddition of 3-vinylcephalosporin with nitrone gave diastereomeric isomers of 3-(isoxazolidin-5-yl)cephalosporin. The antibacterial activities of 3'-(S)-isomers were superior to those of 3'-(R)-isomers. The quaternarization of isoxazolidine ring increased the antibacterial activity. Among them, compound 10b with a hydroxyimino group in the C-7 side chain showed potent activities against staphylococci and compound 10f with an N-hydroxypyridone exhibited an excellent antipseudomonal activity.

Anti-Bacterial Agents↗
PubMed1992

A new tetracycline antibiotic with antitumor activity. I. Taxonomy and fermentation of the producing strain, isolation and characterization of SF2575.

A new antitumor antibiotic SF2575 has been isolated from a culture filtrate of Streptomyces sp. SF2575. The molecular formula was determined to be C40H43NO15 by elemental analysis, mass and 13C NMR spectral analyses. The spectral data revealed SF2575 to be a new tetracycline antibiotic. It was active against Gram-positive bacteria and exhibited antitumor activity against P388 leukemia in mice.

Animals↗
PubMed1992

A new tetracycline antibiotic with antitumor activity. II. The structural elucidation of SF2575.

The structure of a new antitumor antibiotic SF2575, has been determined by spectroscopic analyses of the antibiotic and its alkaline degradation products. The relative stereochemistry has been confirmed by X-ray crystallographic analysis. The antibiotic has a 2-naphthacenecarboxamide carbon skelton which is structurally related to the tetracycline antibiotics and it is unique by bearing C-glycoside, salicyclic acid and angelic acid moieties.

Antibiotics, Antineoplastic↗
PubMed1992

Syntheses and activities of some bactobolin derivatives.

Some derivatives of bactobolin were prepared from bactobolin by dehydration or substitution reactions through tris(dimethylamino)alkoxyphosphonium salt formation. A derivative with low toxicity, 6-deoxybactobolin, showed moderate activity against Gram-positive and Gram-negative bacteria including methicillin-resistant Staphylococcus aureus.

Animals↗
PubMed1992

Totally synthetic analogues of siastatin B. II. Optically active piperidine derivatives having trifluoroacetamide and hydroxyacetamide groups at C-2.

Siastatin B analogues, optically active 2-(trifluoroacetamide)- 3,4,5-trihydroxypiperidines having nitromethyl, aminomethyl and carboxyl branched groups at C-5, and (+)-(2R,3R,4R,5R)-5-(aminomethyl)-3,4,5-trihydroxy-2- (hydroxyacetamido)piperidine have been obtained total synthetically from D-ribono-1,4-lactone. Some analogues have inhibitory activity against some glycosidases, and (+)-(2R,3R,4R,5R)-2-(trifluoroacetamido)-3,4,5-trihydroxypiperi dine-5-carboxylic acid showed a marked inhibitory activity against beta-glucuronidase.

Anti-Bacterial Agents↗
PubMed1992

Werner's syndrome: no difference in in vitro life span of dermal fibroblasts from proximal and distal parts of the body.

Recently it has been reported that fibroblasts from distal parts of the body of a patient with Werner's syndrome grew poorly in vitro as compared with those from the proximal part of the same patient. To confirm this observation, cultures of fibroblasts from different parts of the body were set up in 2 cases of Werner's syndrome, but no significant difference in life span was observed. Fetal calf serum (FCS) and fibroblast growth factor (FGF) stimulated growth of fibroblasts from different body parts equally well. These data indicate that there is no difference in growth activity of fibroblasts from proximal and distal body parts in patients with Werner's syndrome. Moreover, the growth rate of epidermal outgrowths did not differ significantly between proximal and distal parts of these patients.

Adult↗
PubMed1992

The 6-azauridine analogues possessing sedative and hypnotic effects.

Pharmacological effects of 6-azauridine (4) analogues were evaluated using hypnotic activity, pentobarbital (PB)-induced sleep prolongation and locomotor activity as indices. Compound 4, N3-benzyl- (10), N3-o-xylyl- (11), N3-m-xylyl- (12), N3-p-xylyl- (13), N3-alpha-phenylethyl-substituted 6-azauridine (14) exhibited hypnotic activity and PB-induced sleep prolongation, whereas N3-alkyl substituted analogues (methyl-, ethyl-, n-propyl-, n-butyl- and allyl-substitution) did not. Compound 4 and xylyl analogues (11-13) significantly decreased locomotor activity of mice by i.c.v. injection and produced motor incoordination. The results indicate that 4 and its benzyl related analogues, but not alkyl analogues have depressant effects on the central nervous system (CNS).

Animals↗
PubMed1992

An unusual growth pattern of a mucin-producing intrahepatic cholangiocellular carcinoma involving the hepatic hilus.

The case of a mucin-producing intrahepatic cholangiocellular carcinoma in a 73 year-old-man is presented. A tumor originating in the right posterior inferior segment of the liver was found to be invading the right posterior and anterior bile ducts, and the hepatic hilus. Extensive superficial spread was observed in the entire posterior segmental bile duct extending to the hepatic hilus. Mucin produced and excreted by the tumor was retained in the common hepatic and common bile duct. The diagnosis in this case was suggested by percutaneous transhepatic aspiration of mucinous bile, and was confirmed by utilizing the techniques of ultrasonography, percutaneous transhepatic cholangiography, computed tomography and angiography. Curative surgery, which included right hepatic lobectomy with total caudate lobectomy and bile duct resection, was performed. Biliary continuity was maintained by left hepaticojejunostomy using a Roux-en-Y jejunal loop. The histological diagnosis was mucin-producing papillary adenocarcinoma originating in the right posterior inferior segment of the liver. Postoperative recovery was very good and the patient has now been enjoying a good active social life for the last 20 months with no signs of tumor recurrence. This case report discusses the unusual growth pattern of a mucin-producing intrahepatic cholangiocellular carcinoma involving the hepatic hilus, and suggests rational surgical treatment.

Adenocarcinoma, Mucinous↗
PubMed1992

Cytotoxic drug and cytotoxic drug/G-CSF mobilization of peripheral blood stem cells and their use for autografting.

We analysed 99 courses of leukapheresis after the use of cytotoxic drugs or cytotoxic drugs plus G-CSF (cytotoxic/G-CSF) to mobilize peripheral blood stem cells (PBSC) in 68 patients with hematologic or solid malignancies. Mean yields of granulocyte-macrophage progenitor cells (CFU-GM) with cytotoxic/G-CSF mobilization were significantly higher than those with cytotoxic mobilization (18.6 vs 8.40 x 10(4)/kg). The optimal timing of collection was different between these two mobilizations; the mean number of days to a peak level of circulating CFU-GM after cytotoxic/G-CSF mobilization was less than that after cytotoxic mobilization (24.2 vs 27.7 days). The leukocyte level on the day of peak CFU-GM was significantly higher in cytotoxic/G-CSF mobilization than that in cytotoxic mobilization (mean 12.8 vs 2.7 x 10(9)/l), whereas the platelet level was not different (mean 132 vs 125 x 10(9)/l). Increasing patient age was not a major adverse factor for PBSC collection. Synchronous recovery of both leukocytes and platelets was critical for achieving a high CFU-GM yield in these two mobilizations. Following PBSC autotransplantation, the rate of trilineage hematologic reconstitution showed a significant correlation with the infused dose of CFU-GM, whether they were collected with cytotoxic or cytotoxic/G-CSF mobilization. These results suggest that G-CSF can expand the PBSC pool and that CFU-GM yield after cytotoxic/G-CSF mobilization may predict trilineage hemopoietic reconstitution after ABSCT, as well as cytotoxic mobilization.

Adolescent↗
PubMed1992

High resistance of cultured Mongolian gerbil cells to X-ray-induced killing and chromosome aberrations.

The Mongolian gerbil (Meriones unguiculatus) is known to be one of the most radioresistant animals. We have examined the X-ray sensitivity of normal diploid fibroblasts from Mongolian gerbil embryos compared with those of cultured embryo cells obtained from various laboratory animals and a normal human. There was a wide difference in X-ray sensitivity for cell killing among different mammalian species. The D0 values for Mongolian gerbil cells ranged from 2.08 to 2.28 Gy, values which are twice as high as those for human cells. The mean D0 value for human cells was 1.06 Gy. Mouse, rat, Chinese hamster, and Syrian/golden hamster cells showed similar D0 values ranging from 1.30 to 1.56 Gy. When cells were irradiated with X rays, ten times more chromosome aberrations were detected in human cells than in Mongolian gerbil cells. The frequencies of chromosome aberrations in other rodent cells were between the values for cells from humans and those from gerbils. These data indicate that the Mongolian gerbil cells are resistant to X-ray-induced cell killing and chromosome aberrations, and that the radiation sensitivity of mammalian cells in primary culture may be reflected by their radioresistance in vivo.

Animals↗
PubMed1992

[Diagnosis and management of benign biliary strictures with percutaneous transhepatic cholangioscopy (PTCS)].

From January 1981 through March 1991, we encountered twenty four cases of benign biliary strictures. In 10 cases of anastomotic stricture, percutaneous dilatation was carried out in 1 patient under fluoroscopy and in 3 patients under PTCS without recurrence. Endoprosthesis with silicone or polyurethane catheters was carried out under PTCS in 5 patients. One of them died of hepatic failure due to clogging of the catheter, and in other four patients the endoprosthetic catheter was dislodged spontaneously or removed by PTCS because of dislodgement or obstruction of the catheter, and PTCS revealed that the anastomotic stricture had improved. Reoperation of cholangiojejunostomy was carried out in 1 patient, who died of hepatic failure 5 years later due to recurrent of stricture. In 8 cases of the iatrogenic and 1 case of traumatic stricture, percutaneous dilatation was carried out (1 under fluoroscopy and 4 under PTCS) without recurrence. Cholangiojejunostomy was carried out in 3 cases without anastomotic stricture. PTCS was performed for 5 cases of the inflammatory stricture of the hepatic hilus due to cholecystitis to confirm the histological findings by cholangioscopic biopsy. And all cases could be managed by cholecystectomy. Authors recommend that PTCS should be used for the diagnosis and treatment of benign biliary stricture.

Aged↗
PubMed1992

Low toxic derivatives of istamycin B: synthesis and preliminary evaluation.

3-O-Demethylistamycin B derived from istamycin B was one of the most potent aminoglycoside antibiotics against various bacteria. 3-O-Demethylistamycin B, however, showed considerable acute toxicity in mice. The authors attempted to prepare the derivatives of istamycin B having high potency and low toxicity. The selective N-acylation or N-amidination at the C-2 position of istamycin B could not improve the acute toxicity. The replacement of the amino group at the C-2 position of istamycin B by a hydroxyl group markedly decreased the acute toxicity. Among 2'-deamino-2'-hydroxyistamycins, 4-N-(beta-alanyl)-2'-deamino-3-O-demethyl-2'-hydroxyistamycin B0 (9d) showed good antibacterial activity against Gram-positive and Gram-negative bacteria and a low acute toxicity in mice.

Aminoglycosides↗