Azoxybacilin, a novel antifungal agent produced by Bacillus cereus NR2991. Production, isolation and structure elucidation.
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Aminobutyrates↗
Biomedical subjects
H Shimada
Publications and source records attributed to H Shimada.
A new methionine antagonist that has antifungal activity: mode of action.
A new antifungal, azoxybacilin (an unusual amino acid with an azoxy moiety) was identified from Bacillus cereus, and its in vitro antifungal activity and mode of action were investigated. Azoxybacilin was active against a broad spectrum of fungi. It was especially active against mycelial fungi, such as Aspergillus, and did not show antibacterial activity. No cross-resistance with antifungals currently on the market was observed. The IC50 values of azoxybacilin antifungal activity against Saccharomyces cerevisiae were significantly greater when amino acids containing sulfur were added to the growth medium, whereas other amino acids were not effective at all. We, therefore, tested the effect of the intermediates involved in the synthetic pathway of these amino acids. The activity markedly diminished when one of the following four intermediates was present in the medium:homocysteine, cysteine, cystathionine or methionine. These four intermediates were the same as those required for the growth of the O-acetylhomoserine sulfhydrylase mutant, S. cerevisiae ONO726, indicating that azoxybacilin would inhibit a step or steps in the sulfur-fixation pathway.
Amino Acids↗
Effects of chelating agents on tissue distribution and excretion of nickel in mice.
N-Benzyl-D-glucaminedithiocarbamate (BGD), diethyldithiocarbamate (DDTC), di-hydroxyethyldithiocarbamate (DHED), trans-1,2-cyclohexanediamine N,N,N',N'-tetra-acetic acid (CDTA), and 2,3-dimercaptosuccinic acid (DMSA) were studied for their relative efficacies in the distribution and excretion of nickel in mice exposed to nickel. Mice were injected intraperitoneally with NiCl2 (5mgNi/kg) and 30 min or 24 hr later, they were injected intraperitoneally with chelating agents (400 mumol/kg). At 30 min after treatment with nickel, these chelating agents all significantly enhanced the fecal excretion of nickel, and DMSA significantly increased the urinary excretion of the metal. At 24 hr after nickel treatment, BGD, DDTC, and DHED significantly increased the fecal excretion of nickel and BGD was the most effective on the fecal excretion of nickel. CDTA and DMSA significantly enhanced the urinary excretion of the metal. At 30 min after nickel treatment, chelating agents other than CDTA effectively depressed nickel concentration in the kidney, lung, and testes. BGD, CDTA, and DMSA significantly reduced the nickel concentration in the liver. However, DDTC and DHED caused the redistribution of nickel to the brain. At 24 hr after nickel treatment, these chelating agents were effective in mobilizing nickel from the kidney, and chelating agents other than DHED were effective in mobilizing nickel from the liver, lung, and testes. These results indicate that the injection of BGD or DMSA at both 30 min and 24 hr after treatment with nickel can remove nickel from the body without redistribution of nickel to other tissues, such as brain, more effectively than DDTC, DHED, and CDTA. Furthermore, the pattern of excretion of nickel after treatment with the chelating agents was related to the partition coefficients of the nickel-chelating agent complexes.
Animals↗
Increase in adhesion molecules on CD4+ cells and CD4+ cell subsets in synovial fluid from patients with rheumatoid arthritis.
OBJECTIVE: To elucidate the role of adhesion molecules in the pathogenesis of rheumatoid arthritis (RA). METHODS: We evaluated their expression and that of an activation marker on CD4+ cell populations and CD4+ cell subsets in specimens of peripheral blood (PB) and synovial fluid (SF) obtained from 10 patients with RA and 7 with osteoarthritis (OA). A 2 or 3-color immunofluorescent method was used for analysis. RESULTS: The SF from both groups of patients showed a greater density of adhesion molecules including LFA-1 alpha, LFA-1 beta, CD2, VLA-4 alpha and VLA-5 alpha on CD4+ cells, and a higher percentage of CD4+HLA-DR+ cells compared with their PB. IN PB-CD4+ cell subsets from the arthritic and healthy subjects, the CD4+CD45RO+ cell population showed an increased expression of adhesion molecules compared with CD4+CD45RA+ cell population. The expression of adhesion molecules on circulating CD4+ cell population and CD4+ cell subsets from the patients with RA and OA was comparable to that from healthy subjects. SF from both groups of patients showed a higher percentage of CD4+CD45RO+ cells and a lower percentage of CD4+CD45RA+ cells. In SF-CD4+ cell subsets from patients with RA, the CD4+CD45RO+ cell population had an increased expression of VLA-4 alpha compared to the CD4+CD45RA+ cell population; however, there was no significant difference in other adhesion molecule expression and the percentage of HLA-DR+ cells between the 2 cell subsets. Furthermore, the expression of VLA-4 alpha on the CD4+CD45RO+ cell population in SF from patients with RA was significantly higher than that in matched PB. In CD4+CD45RA+ cell population from both groups of patients, SF showed an enhanced expression of adhesion molecules and an increased percentage of HLA-DR+ cells compared with matched PB. CONCLUSION: Our results suggest that increased expression of adhesion molecules and increased percentage of HLA-DR+ cells on CD4+ cells in SF may be responsible for cellular interactions between these cells and synovial cells or extracellular matrix.
Adult↗
[A study of regional chemotherapy: hepatic arterial infusion for metastatic liver tumors].
This study was designed to evaluate whether intraarterial and intra-portal infusion chemotherapy was effective in 57 patients with liver metastases from colorectal cancer and 10 from gastric cancer. Arterial infusion was effective to prevent recurrence in the remnant liver after resection of liver metastases from colorectal cancer. On the other hand, intra-portal infusion was not effective to prevent recurrence. In the patients with unresectable metastases, arterial infusion was also effective for the response rate, which was 75% (with intra-portal infusion) and 27 % (arterial infusion only), respectively. However, arterial infusion had no effect in patients with metastases from gastric cancer. As a result, arterial infusion was effective to prevent recurrence after resection of metastases, and to increase the survival rate in patients with unresectable metastases from colorectal cancer.
Antineoplastic Combined Chemotherapy Protocols↗
[An early phase II clinical study of RP56976 (docetaxel) in patients with breast cancer].
An early phase II clinical study of RP56976 (docetaxel), a new anticancer agent of plant origin, was conducted in patients with breast cancer at 20 Japanese collaborative institutions. Docetaxel was administered at two or more doses of 60 mg/m2 by intravenous infusion with dose-free intervals of 3-4 weeks, and the efficacy and safety was evaluated. Of the 51 patients enrolled, 50 patients completed the scheduled course of treatment. Two patients showed a complete response (CR) and 19 showed a partial response (PR) with a response rate of 42.0%. The response rates based on the efficacy for metastatic lesions in soft tissue, liver and lung, were 46.2% (18/39), 37.5% (3/8), and 38.5% (5/13), respectively. Of the 50 patients who completed the study, 48 patients had previously been treated for the present malignancy. Forty-seven patients had previously been treated with chemotherapy and showed a response rate of 40.4% (19/47). The response rate in those who had received chemotherapy composed of anthracyclines and other agents was 44.1% (15/34). Grade 3 or more severe leukopenia and neutropenia developed in 43 patients (84.3%) and 48 patients (94.1%), respectively. Other adverse reactions which occurred in a Grade 3 or more severe form included nausea/vomiting (1 patient), anorexia (5 patients), diarrhea (4 patients), fatigue (2 patients), and alopecia (20 patients). Except for alopecia, most adverse reactions were generally transient and reversible without any specific treatment.
Adult↗
[Infiltrative peripheral neuropathy of acute monoblastic leukemia during hematologic remission].
A 38-year-old woman with acute monoblastic leukemia developed severe continuous pain in the left arm while she was in hematologic remission following both systemic and intrathecal chemotherapy. A nerve conduction study (NCS) showed marked decrease of amplitude in the left ulnar nerve, consistent with infiltration of leukemic cells. The pain in the arm was reduced by irradiation to the left brachial plexus, but right facial nerve palsy occurred. No improvement was achieved by systemic and intrathecal chemotherapy plus irradiation to the whole brain and right parotid. After sometime, she complained of pains in the legs and right foot drop. NCS showed amplitude decrease in bilateral peroneal nerve. Throughout the course, bone marrow remained in complete remission, and no signs of meningeal leukemia were obtained. A treatment with high dose Ara-C appeared to be effective for the pain in the legs. The foot drop, however, persisted and peripheral neuropathy progressed even after high dose Ara-C therapy. Peripheral nerve involvement in acute leukemia appears to be rare, and even more so in case of hematologic remission. The blood-nerve barrier may allow some malignant cells to escape from cytotoxic agents. Therefore, irradiation or high dose Ara-C therapy would seem to be rational approaches to the problem.
Adult↗
High affinity nerve growth factor receptor expression (gp140trkA), N-myc amplification, histopathology, and survival in neuroblastoma.
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Blotting, Northern↗
A long polypyrimidine:polypurine sequence in 5' flanking region of arylsulfatase gene of sea urchin embryo.
Sea urchin (Hemicentrotus pulcherrimus) arylsulfatase(Ars) gene contains a long (622 bp) polypyrimidine:polypurine (Pyr-Pur) sequence in its 5' flanking region. The Pyr-Pur sequence inserted into a plasmid was sensitive to S1 nuclease at a low acidic pH (pH 5) when the plasmid was negatively supercoiled. From the distribution pattern of S1 sites in the Pyr-Pur region it is concluded that a (CT)11:(GA)11 tract in this region could adopt an unusual DNA configuration distinct from the usual B-form. Another feature of the Pyr-Pur sequence is that this (CT)11:(GA)11 tract is sandwiched by two oligo(dC):oligo(dG) stretches (G-strings) that are located at almost an equal distance from both ends of the (CT)11:(GA)11 tract. Mobility shift assay and DNase-I footprinting revealed that the gastrula nuclei contain nuclear proteins that interact with two distinct oligo(dG):oligo(dG) tracts (G-strings) in the Pyr-Pur region. The possibility is suggested that G-strings may be related to formation and stabilization of an unusual DNA configuration of a (CT)11:(GA)11 tract.
Animals↗
Effect of terbium on protease activity in pancreas of mice.
The effect of terbium (Tb) on the protease activity in pancreas of mice was studied. Administration of Tb at doses of 20 and 200 mumol/kg increased the activities of trypsin and carboxypeptidase A, but did not affect the activities of chymotrypsin and carboxypeptidase B. High Tb concentrations were found in the liver and spleen compared to the kidney and pancreas. Increases in Ca concentrations in the pancreas, kidney, and spleen after Tb administration were observed. The pancreatic slice experiments showed the increase in trypsin activity after Tb treatment and increases in trypsin and carboxypeptidase A after Ca treatment. Tb inhibited strongly the activities of authentic chymotrypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Tb administration results from the activation of trypsinogen by Tb and Ca ions and that the increase in carboxypeptidase A activity is due to the activation of procarboxypeptidase A by trypsin and Ca ion, which increased after Tb administration.
Amino Acid Sequence↗
Mutagenicity study of the new cognition-enhancing agent nefiracetam.
A new cognition-enhancing agent, nefiracetam (N-(2,6-dimethylphenyl)-2- (2-oxo-1-pyrrolidinyl) acetamide, DM-9384, CAS 77191-36-7) was studied for mutagenicity by using the following short-term in vitro and in vivo tests: 1. reverse mutation test (Ames method) on S. typhimurium and E. coli, 2. cytogenetic test on Chinese hamster cells, and 3. mouse micronucleus test. In the cytogenetic study, nefiracetam caused a slight but significant increase of chromosomal aberration at the highest dose in the 48 h treatment group, but no mutagenicity was observed with the same indicator in the in vivo micronucleus test. Furthermore, nefiracetam did not show any positive response in the reverse mutation test. These results suggest that nefiracetam has no biologically significant respectively relevant mutagenic potential.
Animals↗
Inhibition of invasion of HT1080 sarcoma cells expressing recombinant plasminogen activator inhibitor 2.
Plasminogen activators (PA) elaborated by tumor cells play an important role in the complex process of tissue invasion and metastasis. In the present study the effect of the PA inhibitor type 2 (PAI-2) on tissue invasion in vitro and in vivo was investigated. Clones either expressing (B-) or not expressing the endogenous PAI-2 gene (C+) were isolated from the human HT1080 fibrosarcoma cell line and transfected with full-length PAI-2 cDNA. Recombinant PAI-2 (rPAI-2) expressed by these cells completely inhibited receptor-bound urokinase activity and partially neutralized secreted PA activity. Degradation of extracellular matrix proteins by these transfected cells was markedly decreased when compared to mock or untransfected control cells. The rPAI-2-expressing cells did not penetrate a multilayer of rat smooth muscle cells in vitro, which was readily invaded and destroyed by control cells. The PAI-2 transfectants remained tumorigenic in athymic/nude mice, but tumors originating from these cells showed the presence of a thick, collagenous capsule absent in tumors formed by control cells. Thus, expression of rPAI-2 in HT1080 cells resulted in neutralization of receptor-bound urokinase with subsequent inhibition of matrix protein degradation and invasion in vitro and induction of a thick, peritumoral capsule in vivo.
Animals↗
Essential role of the Arg112 residue of cytochrome P450cam for electron transfer from reduced putidaredoxin.
Cytochrome P450cam (CYP101) of Pseudomonas putida PpG1 in which Arg112 is substituted by Cys was isolated by in vitro random mutagenesis of the camC gene DNA coding for P450cam. The absorption spectra of the purified mutant enzyme were similar to those of the wild type enzyme, but its substrate-dependent NADH oxidation activity in the presence of putidaredoxin (Pd) and putidaredoxin reductase (PdR) was extremely low. The rate constant of electron transfer from reduced Pd to the heme of the mutant P450cam, measured on an anaerobic stopped flow apparatus, was 1/400 of that of the wild type enzyme and the dissociation constant of the mutant P450cam for oxidized Pd was several fold higher than that of the wild type enzyme. A considerable decrease in mid-point potential of the mutant enzyme was also noted. We conclude that Arg112, which is located on the surface of the P450cam molecule and hydrogen-bonded to one of the heme propionate chains, plays an essential role in the electron transfer from Pd.
Arginine↗
Establishment and characterization of a human mixed-lineage, T-lymphoid/myeloid cell line (USP-91).
We report the establishment of a novel cell line from a pediatric patient with recurrent non-Hodgkin's lymphoma. This cell line, termed USP-91, showed both T-lymphoid cell as well as myeloid (ie, nonlymphoid) cell characteristics using a comprehensive multiparameter approach. The initial growth of this cell line was dependent on the presence of the murine stromal cell line, 14F1.1. Subsequently, a phenotypically stable, stroma-independent cell line was established. Although the recurrent biopsy material and the derivative cell line, USP-91, were clonally-derived from T-lineage lymphoid cells, as evidenced by the same rearrangement of the T-cell receptor-beta locus, USP-91 coexpressed both the T-cell antigens CD7, CD3, and CD4, and the myeloid antigens CD13, CD33, CD11b, and CD34. The myeloid features of USP-91 were most consistent with monocytic differentiation as these cells expressed alpha-napthol acetate esterase, lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, as well as the cell surface receptor for macrophage colony-stimulating factor. In addition, incubation in the presence of phorbol esters induced USP-91 to exhibit morphologic and functional properties of mature mononuclear phagocytes. The expression of this bilineage phenotype suggests that USP-91 represents the malignant transformation of a progenitor cell capable of either myelomonocytic or T-lymphoid differentiation.
Animals↗
Alteration of the structural properties of starch components by the lack of an isoform of starch branching enzyme in rice seeds.
This study describes the effect of starch-synthesizing enzymes on biosynthesis of storage starch in rice amylose-extender mutants, which contain branched D-glucans with abnormal structures. Western blot analysis indicated that two out of five amylose-extender mutant lines lacked an isoform of starch branching enzyme, termed RBE3, although the levels of granule-bound starch synthase and a major form of branching enzyme, RBE1, were normal in these two mutants. Proteins corresponding to the 87-kDa RBE3 molecule were present in the three other amylose-extender mutants as well as in the wild type. However, the level of branching enzyme activity significantly decreased in all amylose-extender mutants, suggesting that the 87-kDa proteins in these three mutants are inactive forms of RBE3. Therefore, we conclude that formation of the abnormal branched glucans in the amylose-extender mutant of rice is due to the lack of the RBE3 activity. The cDNA clones encoding RBE3 have been identified from a normal rice seed cDNA library in lambda gt11, using a synthetic oligonucleotide as a probe. The deduced amino acid sequence of RBE3 indicates that this protein is initially synthesized as a precursor of 825 amino acids, including a 65-residue transit peptide at the NH2 terminus. The sequences of the catalytic regions in amylolytic enzymes are highly conserved in the sequence of RBE3. Thus, the branching enzyme isoform belongs to a family of the amylolytic enzymes. RBE3 also shares a noticeable degree of sequence identity with RBE1, especially at the central portion of the protein molecule. However, RBE3 possesses an approximately 70-residue extra sequence at the NH2 terminus and lacks a COOH-terminal sequence of almost 50 residues as compared with RBE1. The structural differences at both termini may explain the distinct role in starch synthesis for RBE1 and RBE3.
1,4-alpha-Glucan Branching Enzyme↗
A putative transcription factor binding to the upstream region of the puf operon in Rhodobacter sphaeroides.
Gel shift assays of the upstream region of the puf operon in Rhodobacter sphaeroides were performed using cell-free extracts from cells grown under various culture conditions. The results suggested that a protein binding to the upstream region functioned as a repressor-like substance of the expression of the operon by oxygen tension or light. The density of the shifted band of cell-free extracts from cells irradiated with blue light under semi-aerobic conditions was higher than that with red light. Phosphatase treatment of the cell-free extracts strongly increased the DNA-binding affinity of the protein.
Base Sequence↗
The gene encoding a calcium-dependent protein kinase located near the sbe1 gene encoding starch branching enzyme I is specifically expressed in developing rice seeds.
A gene (spk) encoding a Ca(2+)-dependent protein kinase (SPK) is located in the region immediately upstream of the sbe1 gene encoding a starch branching enzyme. The spk gene is specifically expressed in developing seeds and its expression pattern is very similar to those of genes encoding starch-synthesizing enzymes such as sbe1 and waxy, seed lipid-synthesizing enzymes, as well as genes encoding seed storage proteins. A full-length spk cDNA was isolated from a cDNA library constructed from developing seeds. The deduced amino acid sequence showed that SPK has a high degree of homology to soybean and carrot Ca(2+)-dependent protein kinase, both of which contain calmodulin domains. The calmodulin domain, as well as the catalytic subdomain consensus regions of protein kinases are highly conserved in SPK. These results suggest that a tissue- and stage-specific protein kinase, SPK, is involved in the synthesis of seed storage compounds during seed development. They also strongly suggest that Ca2+ is required for seed development.
1,4-alpha-Glucan Branching Enzyme↗
Malignant rhabdoid tumor. A study with two established cell lines.
BACKGROUND: Malignant rhabdoid tumor (MRT), originally described as a rare renal sarcoma in childhood, has been known to express phenotypic diversity. In this study, unique characteristics of the MRT cells were investigated by using established cell lines. METHODS: Immunocytochemical, ultrastructural, cytogenetic, and molecular (by polymerase chain reaction, PCR) analyses were done for two MRT cell lines, one of renal and one of extrarenal origin, before and after differentiation-induction with either 12-O-tetradecanoyl phorbol-13-acetate (TPA) or transretinoic acid (RA). RESULTS: The proliferating cells in the original tumor tissues as well as in the established cell lines demonstrated neural, epithelial, and mesenchymal markers morphologically. Both cell lines had karyotypic abnormalities including chromosome 22q11.2. The cell line from the extrarenal MRT, Tm87-16, demonstrated distinct morphologic changes with neuroblastic differentiation and produced numerous neuritic processes after treatment with either TPA or RA. The cell line from the renal MRT, STM91-01, suggested schwannian differentiation but did not change morphologically after chemical induction. Both cell lines expressed c-myc, but did not express N-myc, MyoD1, tyrosine hydroxylase, or neural cell adhesion molecule (N-CAM). With PCR and immunocytochemical study, a high level of chromogranin expression was detected by the cells of Tm87-16 only after TPA induced differentiation. CONCLUSIONS: MRT cells demonstrated diverse phenotype of neuro-ecto-mesenchymal differentiation. The results of this study suggest that MRT may be derived from a primitive pluripotential cell, such as neural crest or equivalent. MRT, therefore, might be categorized as one of the subsets of primitive neuroectodermal tumor.
Gene Expression Regulation, Neoplastic↗