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C Finance

Publications and source records attributed to C Finance.

At least 19 recordsLinked to original sources
PubMed2006

[Towards new antibacterial drugs. Interest of para-guanidinoethylcalix[4]arene].

We present here the results concerning the antibacterial properties evaluation of para-guanidinoethylcalix[4]arene, compared with its constitutive monomer, the para-guanidinoethylphenol, and hexamidine (Hexomédine), an antiseptic from the diamidine family widely used in therapeutic, chosen as a reference in this study for its resemblance in terms of functional groups. Antibacterial activities of those three compounds were evaluated by microdilution methods, in Mueller Hinton broth, onto 5 bacterial strains: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 & ATCC 29213 and Enterococcus faecalis ATCC 29212, according to CA-SFM and CLSI (formerly NCCLS) approved standards. In parallel, the effects of these three compounds on MRC-5 eukaryotic cell viability were evaluated with MTT assay. The results obtained here confirm a lack of activity for the monomer compound (MIC> or =512 mg/l) and a real antibacterial activity for the calixarene, comparable to hexamidine. This activity is expressed, both on Gram+and Gram- bacteria (MIC=4 mg/l for E. coli, 8 mg/l on both S. aureus strains) and at a lesser degree on E. faecalis and P. aeruginosa (MIC=32 mg/l). Similarly, both compounds, monomer and calixarene, slightly induce any modification on MRC-5 cells viability, and this until 168 h of treatment for concentrations reaching 10(-4) mol/L while hexamidine demonstrates a significant and increasing effect during the time of experiment and this for 100 to 1000 times lower concentrations. Thus, this study tends to confirm the significance of the organization of the para-guanidinoethylphenol monomer into its cyclic calixarenic tetramer for the gain of an antibacterial activity, similar to a widely used antiseptic one.

Anti-Bacterial Agents↗
PubMed2001

Effect of the complexation with cyclodextrins on the in vitro antiviral activity of ganciclovir against human cytomegalovirus.

The toxicity of the molecules currently used in the treatment of human cytomegalovirus (HCMV) in immunocompromised hosts often causes interruption of the therapy. Cyclodextrins (Cds), oligosaccharides possessing a hydrophobic cavity, have the property of forming inclusion complexes with a great number of molecules, improving their bioavailability and their biological properties. In this study, we have tested the ability of three native Cds to improve the antiviral effect of ganciclovir (GCV) on two HCMV strains: AD169, a reference susceptible strain, and RC11, a GCV resistant strain. The efficacy of the GCV, expressed in IC50 values, showed no improvement in the presence of alpha-Cd, while the use of beta- and gamma-Cd improved by 6- and 4-fold, respectively, its antiviral activity tested on AD169 strain. The influence of beta- or gamma-Cd on GCV efficiency evaluated on RC11 strain showed a decrease of the IC50. Parallel NMR studies were undertaken in order to characterize formation of [GCV:Cd] complexes. The results showed that complexation between alpha- or gamma-Cd and GCV did not occur. In contrast, spectra proved that beta-Cd formed an inclusion complex with GCV. This complex was characterized in UV-Visible spectrophotometry and the influence of the beta-Cd on the GCV penetration in cells was measured. The use of Cds as carriers of antiviral drugs would be a good alternative to traditional treatment, because it may allow the administration of lower doses and so continuous treatment by reducing the toxic effects of drugs.

Antiviral Agents↗
PubMed1999

Complexation study and anticellular activity enhancement by doxorubicin-cyclodextrin complexes on a multidrug-resistant adenocarcinoma cell line.

Ability of molecular complexes of [Doxorubicin (DX)-cyclodextrin (Cd)] to enhance the anticellular activity of antineoplastic drug Doxorubicin and to reverse its multidrug resistance has been investigated. A spectroscopic study of the alpha, beta, and gamma-[DX-Cds] complexes has been investigated in relation to their biological effects on a multidrug resistant (MDR) human rectal adenocarcinoma cell line (HRT-18). A ten fold enhancement of DX anticellular activity in presence of beta-cyclodextrin alone was detected.

Antineoplastic Agents↗
PubMed1999

Influence of the fluoroquinolone ofloxacin on the intrinsic expression of multidrug resistance phenotype in HCT-8 human colon carcinoma cells.

The influence of antibiotics, particularly ofloxacin (OF), a commonly used antimicrobial fluoroquinolone, on the multidrug resistance (MDR) phenotype of the HCT-8 cell line was studied. This cell line was grown in OF containing medium for several months and the expression of the MDR phenotype was followed through the analysis of the expression and functionality of the P-glycoprotein (Pgp), the chemosensitivity to daunorubicin (DNR), and the mRNA expression of mdr-1, multidrug resistance-associated protein (MRP), and topoisomerase IIalpha and IIbeta genes. Replacement of OF by penicillin streptomycin (PS) resulted in a significant decrease in mdr-1 mRNA expression, which was found to correlate with a decrease in the expression and functionality of the Pgp. After antibiotic starvation for 4 weeks, cells grown in antibiotic-free medium were then exposed to PS or OF; these cells showed an increase in mdr-1 mRNA/Pgp and MRP mRNA expression without a decrease in DNR cytotoxicity. OF cultured cells exhibited a significant increase in Pgp expression without evidence of the functionality of the Pgp. An increase in topoisomerase IIalpha mRNA expression was observed with time and with the number of passages of the cell line without any relationship to the presence of antibiotics in the culture medium. These results showed that extensive use of antibiotics, particularly the quinolones, can modify the phenotype of the HCT-8 colon adenocarcinoma cell line.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1997

beta-Cyclodextrin derivatives as carriers to enhance the antiviral activity of an antisense oligonucleotide directed toward a coronavirus intergenic consensus sequence.

The ability of cyclodextrins to enhance the antiviral activity of a phosphodiester oligodeoxynucleotide has been investigated. A 18-mer oligodeoxynucleotide complementary to the initiation region of the mRNA coding for the spike protein and containing the intergenic consensus sequence of an enteric coronavirus has been tested for antiviral action against virus growth in human adenocarcinoma cells. The phosphodiester oligodeoxynucleotide only showed a limited effect on virus growth rate (from 12 to 34% viral inhibition in cells treated with 7.5 to 25 microM oligodeoxynucleotide, respectively, at a multiplicity of infection of 0.1 infectious particle per cell). In the same conditions, the phosphorothioate analogue exhibited stronger antiviral activity, the inhibition increased from 56 to 90%. The inhibitory effect of this analogue was antisense and sequence-specific. Northern blot analysis showed that the sequence-dependent mechanism of action appears to be the inhibition of mRNA transcription. We conclude that the coronavirus intergenic consensus sequence is a good target for an antisense oligonucleotide antiviral action. The properties of the phosphodiester oligonucleotide was improved after its complexation with cyclodextrins. The most important increase of the antiviral activity (90% inhibition) was obtained with only 7.5 microM oligonucleotide complexed to a cyclodextrin derivative, 6-deoxy-6-S-beta-D-galactopyranosyl-6-thio-cyclomalto-heptaose+ ++ in a molar ratio of 1:100. These studies suggest that the use of cyclodextrin derivatives as carrier for phosphodiester oligonucleotides delivery may be an effective method for increasing the therapeutic potential of these compounds in viral infections.

Cells, Cultured↗
PubMed1994

Recognition ability and cytotoxicity of some oligosaccharidyl substituted beta-cyclodextrins.

This paper reports a chemico-enzymatic synthesis of beta-CD derivatives. The recognition properties of these derivatives were tested using flocculating yeast and isolated lectins. It was observed that the substitution of beta-cyclodextrins with galactose end arms induces the better recognition by a cell-linked galactose-specific lectin. The physicochemical effects of the beta-CD derivatives on membranes were estimated using red blood cells and the effects on the viability of yeast and human rectal tumor cells were appreciated by measuring the mitochondrial deshydrogenase activity. The substitutions of the beta-CD ring by sugar antennae decrease the negative physicochemical effects of the beta-CD, ie their hemolytic properties. However, these substitutions induce significant modifications of the biological properties of the molecules, particularly the cytotoxicity and the growth of eukaryotic cells.

Animals↗
PubMed1993

Novel bioactive compounds from actinomycetes.

Actinomycetes form an enormous reservoir of secondary metabolites and enzymes. The potential for exploiting rare actinomycetes is highlighted by the discovery of novel compounds from strains of Spirillospora and Nocardioides. Novel compounds of well known classes of antibiotics, such as polyenes, continue to be discovered. For compounds containing a chromophore, the analysis by high-performance liquid chromatography coupled with a diode-array detector enables the elimination of producers of known compounds and facilitates the discovery of novel compounds or derivatives. The complexity of the regulatory mechanisms is illustrated by glutamine synthetase. The characterization of thermostable amylolytic, lignolytic, peroxidase and neuramidase activities, and the isolation of novel cellulolytic actinomycetes clearly demonstrate the potential of Actinomycetes as producers of enzymes.

Actinomycetales↗
PubMed1992

Radioactive and enzymatic cloned cDNA probes for bovine enteric coronavirus detection by molecular hybridization.

Genomic RNA of F15 strain bovine enteric coronavirus (BECV) was cloned in E. coli. Three clones (174, 160, PG78), selected in the cDNA library, including a large portion of the nucleocapsid (N), matrix (M) and peplomeric (S) protein genes, were used as probes for a slot blot hybridization assay. Two probe labelling techniques were compared, radiolabelling with 32P and enzymatic labelling through covalent linkage to peroxidase and chemiluminescence detection. The radioactive probe 174 detected as little as 1 to 3 pg of viral RNA, while the less sensitive enzymatic probe could not reveal more than 100 pg of RNA. No significant detection amplification was achieved when a mixture of the three probes was used. Probe 174 allowed specific identification for BECV. No hybridization was noticed either with rotaviruses or even with other antigenically unrelated members of the family Coronaviridae such as transmissible gastroenteritis virus. The test proved valid for detection of BECV in the supernatant of infected HRT-18 cells: genomic RNA could be detected after direct spotting of samples, but prior nucleic acid extraction after proteinase K treatment improved virus detection. BECV diagnosis in faecal samples using enzymatic probe was compared with conventional diagnostic methods.

Animals↗
PubMed1989

Stability of parenteral ceftriaxone disodium solutions in frozen and liquid states: effect of freezing and microwave thawing.

The stability of ceftriaxone disodium solutions stored in glass bottles was tested in two parenteral solvents (0.9% NaCl; 5% dextrose) at two concentration rates (10 and 50 mg/mL) and three temperatures (-22 degrees C, 5 degrees C, room temperature). The solutions, which had been initially frozen, were thawed at room temperature or by exposure to microwave radiations. The stability of each sample was determined by a quantitative bacteriological agar gel diffusion assay and by high-performance liquid chromatography. The results of this study indicate that admixtures of ceftriaxone disodium at the concentration rates tested can be frozen for six months without a significant loss in antibiotic activity. At room temperature, the stability is dependent on the concentration of ceftriaxone disodium. At 5 degrees C, the stability is related to the concentration of ceftriaxone and of the solvent. The results obtained by both analytical methods are very close. In order to perform routine assays, the high-performance liquid chromatography method was chosen on the basis of its rapidity and reproducibility.

Ceftriaxone↗
PubMed1988

Improved method for contamination of mussels by poliovirus.

An experimental method for contaminating mussels with poliovirus that approaches natural conditions in a coastal zone is described. A 280 liter aquarium is used to determine optimum conditions for obtaining a maximum titer of virus in mussels. When mussels were kept for 1 h in water contaminated with from 3 to 368 PFU ml-1, between 1 to 628 PFU g-1 tissue were recovered. Mussels exposed to contaminated water for periods of up to 10 days showed decreased titers of virus which seemed to parallel the natural inactivation of viruses in water with time. 1 h of exposure to contaminated water was always sufficient for a maximum adsorption of viral particles by mussels.

Animals↗
PubMed1985

Recovery of reoviruses from tap water.

Samples of piped water were taken from the source of the springs in ten villages in Lorraine. Usually this water has not been subjected to disinfection. The water was tested for fecal indicator bacteria, phages and animal viruses. Of the ten samples examined, seven contained no fecal indicator bacteria, phages or animal viruses, in three samples, however, Reovirus type 2 was found. Among the three positive samples only one contained fecal bacteria and phages. Consequently, the two other samples could be regarded as drinking water, despite the presence of viruses. Such an approach poses the problem of testing drinking water for viruses and suggests that viral tests should be undertaken as part of the water quality control.

Animals↗
PubMed1982

Viral pollution of seawater at Barcelona.

A virological study of sea water was carried out at Barcelona (Spain) in June and September 1979. Three beaches were sampled in June; the September samples were taken in front of an outlet at 2, 5, 20 and 1,000 m offshore. All of the samples from the 3 beaches contained viruses, at rates varying from 0.12 to 1.72 MPNCU/l. Vaccinal poliovirus type 3 and coxsackie B5 predominated. For the offshore samples, 55% were positive with rates ranging from 0.15 to 0.36 MPNCU/l. Vaccinal poliovirus type 3 was clearly predominant. There was no significant difference in viral pollution rates between 2m and 1,000 m offshore.

Enterovirus B, Human↗
PubMed1981

Improved method for virological analysis of food.

A single, simple method for recovering enteroviruses from several different kinds of food, such as ground beef, fish, oysters, and mussels, has been improved. First, sample contamination technique was studied. It appears that virus adsorption occurs at food pH and varies according to the kind of food and the food-virus exchange surface. Second, virus recovery was evaluated. According to the experimental results obtained, we propose the following method. Samples are submerged in 100 ml of demineralized water adjusted to pH 9 with a conductivity of 8,000 mg of NaCl per liter. Then, viruses are concentrated by ultrafiltration or by ultracentrifugation. This method was efficient for virus recovery from the four kinds of food, even in cases of very low contamination.

Animals↗
PubMed1977

[Correlation between the intensity of spontaneous bacteriolysis and bacterial pollution in superficial waters].

A study on the determination of the intensity of spontaneous bacteriolysis in different samples of water from the hydrographic basin of Lorraine, has led us to propose a new way of expressing the spontaneous bacteriolytic power: PBSG. Its utilization has permitted us to establish correlations between the intensity of spontaneous bacteriolytic power and the degree of bacteriological pollution found in different places in the two rivers, the Moselle and the Meurthe. A very strong correlation has been shown between the rate of global spontaneous bacteriolysis after 6 days and the number of coliforms in the water.

Bacteriolysis↗
PubMed1977

[Attempt to express the spontaneous global bacteriolytic power of water].

The utilization of a technique for the determination of spontaneous bacteriolytic power in surface waters has led us to propose a new way of expressing the spontaneous bacteriolytic power of water: PBSG. PBSG allows us to evaluate the intensity of global spontaneous bacteriolysis and to compare the global spontaneous bacteriolytic powers of different water samples.

Bacteriolysis↗
PubMedDate not supplied

Sequence and analysis of BECV F15 matrix protein.

Clones from the bovine enteric coronavirus (F15) cDNA library were cloned in pBR322 and sequenced by the method of Sanger and Coulson. This led to the identification of a sequence of 1,300 bases which contained a single open reading frame of 690 bases yielding a protein having properties of the matrix protein (M). It was comprised of 230 amino acids with a molecular weight of 26,376 Da. It was hydrophobic and had a net charge of +8 at neutral pH. Analysis of its secondary structure could not establish a simple transmembrane arrangement of the amino acids. Comparison of its nucleotide sequence with that of BECV Mebus strain showed only a two-base change resulting in a 100% homology between the two amino acid sequences. Furthermore, a very conserved structure of M appeared on comparison with the Dayoff optimal alignment of MHV-A59, MHV-JHM, TGEV, IBV Beaudette and IBV 6/82M amino acid sequences. As the two strains of BECV, F15 and Mebus present some antigenic differences, this led us to reconsider the role of M in viral antigen specificity. A hypothesis is that, as it seems to possess the necessary information on its transmembrane region, it is an ideal candidate for the viral budding process.

Amino Acid Sequence↗