Hepatitis A virus in urban sewage from two Mediterranean countries.

Molecular methods for the detection and typing of hepatitis A virus (HAV) strains in sewage were applied to determine its distribution in Cairo and Barcelona. The study revealed the occurrence of different patterns of hepatitis A endemicity in each city. The circulating strains characterized, whether in Cairo or Barcelona, were genotype IB. The effects of a child vaccination programme and the increase in the immigrant population on the overall hepatitis A occurrence in Barcelona were evaluated. While vaccination contributed to a significant decrease in the number of clinical cases, the huge recent immigration flow has probably been responsible for the re-emergence of the disease in the last year of study, in the form of small outbreaks among the non-vaccinated population

Fine-Tuning Translation Kinetics Selection as the Driving Force of Codon Usage Bias in the Hepatitis A Virus Capsid

Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness

Evaluation of the relationship between effervescent paracetamol and blood pressure: clinical trial

Background: Paracetamol's solubility is achieved by adding to the excipient sodium salts, either as bicarbonate, carbonate or citrate. As the relationship between salt and hypertension is well known, due to the sodium content it has raised a hypothesis that may interfere with the control of that risk factor. Therefore, the objective of this study is to evaluate the effect on blood pressure of effervescent paracetamol compared to non-effervescent, in hypertensive patients. Methods/Design: This is the protocol of a phase IV multicenter clinical trial, randomized, controlled, crossover, open, which will compare the effect of two different formulations of paracetamol (effervescent or non-effervescent) in the blood pressure of hypertensive patients, with a seven weeks follow up. 49 controlled hypertensive patients will be included (clinical BP lower than 150 and 95 mmHg, and lower than 135 mmHg and 85 mmHg in patients with diabetes or a history of cardiovascular event, and daytime ambulatory measurements lower than 140 and 90 mmHg) and mild to moderate pain (Visual Analog Scale between 1 and 4). The study was approved by the ethics committee of the Fundació Jordi Gol i Gurina and following standards of good clinical practice. The primary endpoint will be the variations in systolic BP in 24 h Ambulatory Blood Pressure Monitoring, considering significant differences 2 or more mmHg among those treated with non-effervescent and effervescent formulations. Intention-to-treat and per-protocol analysis will be held. Discussion: Despite the broad recommendation not to use effervescent drugs in patients with hypertension, there are relatively little studies that show exac tly this pressor effect due to sodium in salt that gives the effervescence of the product. This is the first clinical trial designed to study the effect of effervescence compared to the non-effervescent, in well-controlled hypertensive patients with mild to moderate pain, performed in routine clinical practic

Hepatitis A Virus Mutant Spectra under the Selective Pressure of Monoclonal Antibodies: Codon Usage Constraints Limit Capsid Variability▿

Severe structural constraints in the hepatitis A virus (HAV) capsid have been suggested as the reason for the lack of emergence of new serotypes in spite of the occurrence of complex distributions of mutants or quasispecies. Analysis of the HAV mutant spectra under immune pressure by the monoclonal antibodies (MAbs) K34C8 (immunodominant site) and H7C27 (glycophorin binding site) has revealed different evolutionary dynamics. Populations composed of complex ensembles of mutants with very low fitness or single dominant mutants with high fitness permit the acquisition of resistance to each of the MAbs, respectively. Deletion mutants were detected as components of the mutant spectra: up to 61 residues, with an average of 19, and up to 83 residues, with an average of 45, in VP3 and VP1 proteins, respectively. A clear negative selection of those replacements affecting the residues encoded by rare codons of the capsid surface has been detected through the present quasispecies analysis, confirming a certain beneficial role of such clusters. Since these clusters are located near or at the epitope regions, the need to maintain such clusters might prevent the emergence of new serotypes

Capsid Region Involved in Hepatitis A Virus Binding to Glycophorin A of the Erythrocyte Membrane

Hepatitis A virus (HAV) has previously been reported to agglutinate human red blood cells at acidic pHs. Treatment of erythrocytes with different enzymes and chemical reagents indicated that HAV attachment is mediated through an interaction with sialylglycoproteins. HAV hemagglutination could be blocked by incubating the virus with glycophorin A, indicating that this sialylglycoprotein is the erythrocyte receptor. The number of receptors used was estimated to be around 500 per cell. At the same time, HAV-induced hemagglutination could also be blocked by either monoclonal antibody H7C27 or an anti-VP3(102-121) ascitic fluid, indicating that lysine 221 of VP1 and the surrounding VP3 residues lining the capsid pit are involved in HAV binding to erythrocytes

Fine-Tuning Translation Kinetics Selection as the Driving Force of Codon Usage Bias in the Hepatitis A Virus Capsid

Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness