Expression in Escherichia coli of the cloned polyhedrin gene of Bombyx mori cytoplasmic polyhedrosis virus.

Cloned cDNA of genomic segment 10 of Bombyx mori cytoplasmic polyhedrosis virus (CPV) was placed downstream from the lambda PL promoter in expression plasmid pRC23 and expressed in Escherichia coli cells. A polypeptide of the same molecular weight (28 kDa) as natural polyhedrin was synthesized at the level of approximately 10% of total host cell protein. This polypeptide was identified as CPV polyhedrin (r-polyhedrin) after comparative studies.

[Antitumor activity of various cytostatics in mice bearing murine advanced tumors].

Antitumor activities of cytostatics such as 5-FU, 5'-DFUR, cyclophosphamide (CPA), ACNU, CDDP, mitomycin C (MMC) and doxorubicin (DXR) were compared in mice bearing four different murine-tumor models at two different stages of the tumor growth. All cytostatics tested suppressed the tumor growth in most of the four tumors, colon 26 carcinoma, UV 2237 fibrosarcoma, Ehrlich carcinoma and Meth A fibrosarcoma, when the tumor sizes were small (early transplant). When given to mice bearing advanced tumors, 5-FU, CDDP, MMC and DXR were effective only at the higher doses, showing toxicity.

Ro 09-1470 is a selective inhibitor of P-450 lanosterol C-14 demethylase of fungi.

Ro 09-1470 is a new antifungal agent that belongs to a series of compounds characterized by a tetrahydropyran skeleton with glycine and alkenyl side chains and that inhibits P-450 lanosterol C-14 demethylase (P-450(14DM)) of fungi (Y. Aoki, T. Yamazaki, M.

Biological characterization of cyclothialidine, a new DNA gyrase inhibitor.

Cyclothialidine is a new DNA gyrase inhibitor isolated from Streptomyces filipinensis NR0484. Structurally, it belongs to a new class of natural products containing a unique 12-membered lactone ring that is partly integrated into a pentapeptide chain. Cyclothialidine was found to be one of the most active of all the DNA gyrase inhibitors tested in the DNA supercoiling reaction of Escherichia coli DNA gyrase; 50% inhibitory concentrations (in micrograms per milliliter) of 0.

Historical aspects of the oral use of retinoids in acne.

A number of investigations of the effects of vitamin A deficiency in animals and man and its treatment with natural products containing vitamin A were carried out in the twenties and thirties. In 1942, a clinical study in patients with acne treated with vitamin A yielded encouraging results. Further trials in the forties and fifties, trying to confirm the beneficial effect of oral vitamin A in acne, met with equivocal success.

Cloning of the chitin synthase 3 gene from Candida albicans and its expression during yeast-hyphal transition.

The chitin synthase 3 gene (CACHS3) has been cloned from Candida albicans. The yeast CAL1 gene encoding the chitin synthase 3 of Saccharomyces cerevisiae was used as a probe for the isolation of the gene from C. albicans.

Multi-center collaborative in vitro studies using a human cancer cell line: the EORTC Preclinical Therapeutic Models Group experience.

The EORTC Preclinical Therapeutic Models Group (PTMG), formerly known as the Clonogenic Assay Screening Study Group (CASSG), began experiments in 1982 to investigate the feasibility of doing collaborative studies using in vitro clonogenic assays. The human colon adenocarcinoma cell line WiDr was selected as the model with which all participating laboratories would work. During the course of these studies, representatives from 34 different institutions located in 10 European countries participated.

The anti-tumor arotinoid Ro 40-8757 protects bone marrow from the toxic effects of cyclophosphamide.

The arotinoid Ro 40-8757 is a novel compound that has significant therapeutic activity against chemically induced breast tumors in rats. The results of combination therapy with cyclophosphamide, plus the arotinoid showed that the anti-tumor effects were additive. However, all of the rats given CPA alone died between week 6 and week 10 of treatment.

Species specificity of pharmacological characteristics of CCK-B receptors.

Novel CCK-B receptor antagonists, tetronothiodin and L-156,586, showed different affinities for CCK-B receptors in brain membranes from human, rat, guinea pig and mouse. [125I]CCK-8 bound to these membranes with a similar affinity. However, tetronothiodin was most potent in rat (IC50 = 3.

Tetrafibricin, a novel fibrinogen receptor antagonist. II. Structural elucidation.

The structure of tetrafibricin, a novel and potent fibrinogen receptor antagonist isolated from the culture broth of Streptomyces neyagawaensis NR0577, was determined. Tetrafibricin has a unique structure containing primary amine, conjugated tetraenoic acid, and polyhydroxy functionalities that is biosynthetically related to the polyene macrolide antibiotics.

Tetrafibricin, a novel fibrinogen receptor antagonist. I. Taxonomy, fermentation, isolation, characterization and biological activities.

Tetrafibricin is a novel fibrinogen receptor antagonist produced by Streptomyces neyagawaensis NR0577. It was isolated from the culture broth by Diaion HP-21 adsorption, MeOH extraction, MCI GEL CHP-20P column chromatography, preparative HPLC and Toyopearl HW-40 SF column chromatography. The physico-chemical properties of tetrafibricin indicated that the structure of tetrafibricin is different from the known peptide fibrinogen receptor antagonists and closely related to the polyene macrolide antibiotics.

Activation of CCK-B receptors elevates cytosolic Ca2+ levels in a pituitary cell line.

Cytosolic Ca2+ levels ([Ca2+]i) in GH3 cells, a rat anterior pituitary tumor cell line, were monitored with fura-2 by fluorescence measurements. Cholecystokinin octapeptide (CCK-8) produced a transient elevation of [Ca2+]i. The elevation of [Ca2+]i by CCK-8 was inhibited by L-365,260, but not by devazepide.

Antagonism of various tonic convulsions in mice by dextrorphan and dizocilpine.

To define their efficacy and mechanism of action, the possible antagonistic effects of intravenously administered dextrorphan and dizocilpine, non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonists, on tonic convulsions and death in a variety of experimental mice models were compared. Dextrorphan not only produced dose-dependent protection against the tonic convulsions caused by an intracerebroventricular injection of NMDA, but also showed a broad spectrum of anticonvulsant activities against tonic convulsions caused by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainic acid (KA), bicuculline, pentylenetetrazole or electroconvulsive shock. The anticonvulsant action of dizocilpine was found to be more efficacious for any type of tonic convulsions and was 20- to 70-fold more potent than that of dextrorphan.

GH3 cells, an anterior pituitary cell line, express CCK-B receptors.

We found that GH3 cells, a rat anterior pituitary tumor cell line, expressed a single class of high-affinity binding sites for radiolabeled cholecystokinin octapeptide (CCK-8) with a Kd of 48 pM. The binding sites had high affinity for CCK-8, CCK-4, gastrin I, and L-365,260 (CCK-B antagonist), and had low affinity for devazepide (CCK-A antagonist), indicating that the binding sites are CCK-B receptors. GTP and its stable analogues inhibited radiolabeled CCK-8 binding to GH3 cell membranes, suggesting a coupling of CCK-B receptors to a G-protein.

Simultaneous determination of a new anticancer drug galocitabine and its metabolites in blood by high-performance liquid chromatography.

A relatively simple and sensitive high-performance liquid chromatographic (HPLC) method is described for measuring galocitabine (Ro 09-1390) and its meatbolites, i.e. 5'-deoxy-fluorocytidine (5'-DFCR), 5'-deoxy-fluorouridine (5'-DFUR) and 5-fluorouracil (5-FU), in blood for the purpose of studying pharmacokinetics and toxicokinetics in small animals.

Cytokines induce uridine phosphorylase in mouse colon 26 carcinoma cells and make the cells more susceptible to 5'-deoxy-5-fluorouridine.

The antiproliferative activity of 5-fluorouracil (5-FUra) and 5'-deoxy-5-fluorouridine (5'-dFUrd), used in combination with typical cytokines and growth factors, was investigated in mouse colon 26 carcinoma cells. Tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha), and interferon gamma (IFN gamma) at low doses showing < 50% inhibition of cell growth by themselves enhanced the susceptibility of the cells to the activity of 5'-dFUrd. In particular, a mixture of these cytokines greatly enhanced the activity of 5'-dFUrd and 5-FUra by up to 12.

Molecular characterization of the 5'-flanking region of human genomic ETA gene.

A clone containing the promoter, the exon 1 and exon 2 of human genomic ETA gene was isolated and sequenced. The transcription initiation site and TATA box were identified at 528 bp upstream of the initiation codon and 24 bp upstream of the transcription initiation site, respectively. The 534 bp fragment containing 5'-flanking sequence and most of the exon 1 of the human ETA gene showed a promoter activity corresponding to 55% of SV40 early promoter activity when placed upstream of the luciferase gene and transfected into CHO cells.

Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp. NR0489. III. Structural elucidation.

Tetronothiodin (1) is a potent and selective cholecystokinin type B (CCK-B) receptor antagonist produced by Streptomyces sp. NR0489. Its structure was elucidated to be a macrocyclic compound comprising cyclohexene, alpha-acyltetronic acid and tetrahydrothiophene moieties based on various 2D NMR experiments on 1 and its dihydro derivative.

Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp. NR0489. II. Isolation, characterization and biological activities.

A novel cholecystokinin type-B receptor antagonist named tetronothiodin has been isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp. NR0489. Tetronothiodin inhibited the binding of CCK8 (C-terminal octapeptide of cholecystokinin) to rat cerebral cortex membranes (CCK type-B receptors) with an IC50 of 3.

Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp. NR0489. I. Taxonomy, yield improvement and fermentation.

Streptomyces sp. NR0489 produces tetronothiodin, a novel brain-type cholecystokinin receptor antagonist. This species was differentiated from its related species S.

Cytokines induce thymidine phosphorylase expression in tumor cells and make them more susceptible to 5'-deoxy-5-fluorouridine.

The present study shows that various cytokines such as tumor necrosis factor (TNF alpha), interleukin-1 alpha (IL-1 alpha), and interferon-gamma (IFN gamma) make tumor cells much more susceptible to the cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) than to 5-fluorouracil (5-FUra) and other cytostatics. These three cytokines increased the susceptibility of human cancer cell lines (COLO201, MKN45 and WiDr) but did not affect that of normal fibroblast WI38 cells. The cytokine mixture induced a 50-fold increase in the susceptibility of COLO201 to 5'-dFUrd, whereas a 12-fold increase and a less than 5-fold enhancement in the susceptibility to 5-FUra and other cytostatics, respectively, were observed.

Identification of specific intracellular domains of the human ETA receptor required for ligand binding and signal transduction.

We have investigated the function of the C-terminal and the third intracellular domains of the ETA receptor by expressing truncated and mutated ETA receptors in COS-7 and CHO cells. All the C-terminal truncated ETA receptors were produced at a similar expression level and were detected in the cell membrane using indirect immunostaining. The sizes of the truncated ETA receptors were decreased in proportion to the molecular mass of the truncated amino acid sequence.

Dextrorphan attenuates the behavioral consequences of ischemia and the biochemical consequences of anoxia: possible role of N-methyl-d-aspartate receptor antagonism and ATP replenishing action in its cerebroprotecting profile.

The acute anti-ischemic and anti-anoxic effects of dextrorphan (DX) were compared with those of dizocilpine (MK-801) in a variety of animal models, and in vivo and in vitro testings under anoxic conditions. DX reduced the incidence of death in ischemic mice and improved the rotarod performance of mice with brain ischemia. The ischemically-impaired memory of mice treated with DX markedly improved, as shown in the step-through type passive avoidance test, Morris water maze and in the habituation of exploratory behavior test.

Functional domains of human endothelin receptor.

The ligand binding site to the ETA receptor was investigated by substitution of each 5-amino acid sequence located in the second extracellular (B) region of the ETA receptor with the cognate sequences of the beta 2-adrenergic receptor. A 5-amino acid sequence (140-KLLAG-144) in the B-loop region was implicated as the most important element required for ligand binding. In addition, both the third and the fourth extracellular regions (C- and D-loops), including the flanking transmembrane regions, were found to play an important role in ligand selection.