In vitro effect of aluminium upon erythrocyte membrane properties

The link between aluminium (Al(III)) and a range of disorders in organisms (plants and animals including human beings) has been stated in diverse studies. As regards as human beings in particular, there are numerous studies on this metal's toxicity in relation to pathological processes. Only few references to the metal's effect upon cell rheological properties can be found. In this study, we present evidence for alterations in the rheological properties of cells as consequence of the Al(III)'s interaction with human red blood cell membrane. Al(III) could damage membrane functions of the red blood cell by favouring lipid peroxidation reactions due to the presence of Fe(II) as an initiator. The metal's effect on lipid bilayer, and probably on the cytoskeleton as well, would constitute the cause for the impaired erythrocyte rheology.

Treatment of chronic he1patitis C genotype 1 with peginterferon-alpha2a (40 kDa) plus ribavirin under routine clinical practice in Spain: early prediction of sustained virological response rate

BACKGROUND

Sustained virological response rates of up to 52% have been obtained with peginterferon alpha2a (40 kDa) plus ribavirin in patients suffering from chronic hepatitis C genotype 1 in randomized-controlled trials.

AIM

To assess early virological response and its clinical utility in predicting an sustained virological response in patients suffering from chronic hepatitis C genotype 1 in routine clinical practice in Spain.

METHODS

Treatment-naïve patients received pegylated interferon alpha2a (40 kDa) 180 microg/week plus ribavirin 1000/1200 mg/day for 48 weeks, and were followed for a further 24 weeks. Overall, 475 patients received at least one dose of medication and were included in the efficacy population.

RESULTS

The overall sustained virological response rate was 48%. Of those with week 12 virological data, 83% had an early virological response. The negative predictive value of an early virological response was 93%.

CONCLUSION

If sustained virological response is the goal, a treatment-decision based on a 12-week evaluation during routine clinical practice is feasible.

Treatment of chronic he1patitis C genotype 1 with peginterferon-alpha2a (40 kDa) plus ribavirin under routine clinical practice in Spain: early prediction of sustained virological response rate

BACKGROUND

Sustained virological response rates of up to 52% have been obtained with peginterferon alpha2a (40 kDa) plus ribavirin in patients suffering from chronic hepatitis C genotype 1 in randomized-controlled trials.

AIM

To assess early virological response and its clinical utility in predicting an sustained virological response in patients suffering from chronic hepatitis C genotype 1 in routine clinical practice in Spain.

METHODS

Treatment-naïve patients received pegylated interferon alpha2a (40 kDa) 180 microg/week plus ribavirin 1000/1200 mg/day for 48 weeks, and were followed for a further 24 weeks. Overall, 475 patients received at least one dose of medication and were included in the efficacy population.

RESULTS

The overall sustained virological response rate was 48%. Of those with week 12 virological data, 83% had an early virological response. The negative predictive value of an early virological response was 93%.

CONCLUSION

If sustained virological response is the goal, a treatment-decision based on a 12-week evaluation during routine clinical practice is feasible.

PA subunit from influenza virus polymerase complex interacts with a cellular protein with homology to a family of transcriptional activators

The PA subunit of the influenza virus polymerase complex is a phosphoprotein that induces proteolytic degradation of coexpressed proteins. Point mutants with reduced proteolysis induction reconstitute viral ribonucleoproteins defective in replication but not in transcriptional activity. To look for cellular factors that could associate with PA protein, we have carried out a yeast two-hybrid screen. Using a human kidney cDNA library, we identified two different interacting clones. One of them was identified as the human homologue of a previously described cDNA clone from Gallus gallus called CLE. The human gene encodes a protein of 36 kDa (hCLE) and is expressed ubiquitously in all human organs tested. The interaction of PA and hCLE was also observed with purified proteins in vitro by using pull-down and pep-spot experiments. Mapping of the interaction showed that hCLE interacts with PA subunit at two regions (positions 493 to 512 and 557 to 574) in the PA protein sequence. Immunofluorescence studies showed that the hCLE protein localizes in both the nucleus and the cytosol, although with a predominantly cytosolic distribution. hCLE was found associated with active, highly purified virus ribonucleoproteins reconstituted in vivo from cloned cDNAs, suggesting that PA-hCLE interaction is functionally relevant. Searches in the databases showed that hCLE has 38% sequence homology to the central region of the yeast factor Cdc68, which modulates transcription by interaction with transactivators. Similar homologies were found with the other members of the Cdc68 homologue family of transcriptional activators, including the human FACT protein.

[Modulation of P-fimbriation by ciprofloxacin in uropathogenic Escherichia coli]

BACKGROUND

The aim of this study was to determine the effect of ciprofloxacin at subinhibitory concentrations on the expression of P fimbriae of uropathogenic Escherichia coli. Thirty-nine strains of Escherichia coli isolated from out patients with urinary tract infection were studied. Thirty-nine of these strains had been previously characterized as P-fimbriated and the remaining non fimbriated strain was used as a negative control.

METHODS

Fimbriation was quantitatively studied by electron microscope observation of the strains before and after treatment. To determine possible qualitative variations in the fimbrial proteins and in the external membrane (OMPs), extraction and electrophoretic separation was performed in polyacrylamide gels.

RESULTS

No qualitative differences were observed in the OMPs profile and fimbrial proteins induced by ciprofloxacin in any of the strains studied. However, electron microscopic observation generally showed a decrease in the percentage fimbriated bacterial cells by the antimicrobial effect.

CONCLUSIONS

The mechanism of action of ciprofloxacin at subinhibitory doses may correspond to a process of fimbrial protein synthesis inhibition secondary to the initiation of general repair mechanism of the cell exposed to the antimicrobial and not to a process of specific mutations which qualitatively affect fimbrial protein composition.