63 research outputs found
Reformulating international pricing: standardization vs. adaptation
We have carried out a deep analysis (using of a meta-analytical approach) of the
Literature published in relation to international pricing. We have formulated a series
of theoretical propositions that we have contrasted with a company inside the
countries of the European Union. We have joined countries of the EU according to
the prices of the analysed product. So, the best statistical tool for that is the cluster
analysis. The second stage of this process is to contrast the price differences
between the countries classified in each cluster. The research reveals the existence
of price adaptation of the analysed company to the diverse environments of the
European Union members
Reformulating international pricing: standardization vs. adaptation
We have carried out a deep analysis (using of a meta-analytical approach) of the
Literature published in relation to international pricing. We have formulated a series
of theoretical propositions that we have contrasted with a company inside the
countries of the European Union. We have joined countries of the EU according to
the prices of the analysed product. So, the best statistical tool for that is the cluster
analysis. The second stage of this process is to contrast the price differences
between the countries classified in each cluster. The research reveals the existence
of price adaptation of the analysed company to the diverse environments of the
European Union members
Characterization of hepatitis B virus X gene quasispecies complexity in mono-infection and hepatitis delta virus superinfection
Hepatitis B X gene; Hepatitis B virus; Hepatitis delta virusHepatitis B gen X; Virus d'hepatitis B; Virus d'hepatitis deltaHepatitis B gen X; Virus de hepatitis B; Virus de hepatitis deltaBACKGROUND:
Hepatitis delta virus (HDV) seems to strongly suppress hepatitis B virus (HBV) replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein (HBx) is essential for HBV replication, determination of HBV X gene (HBX) quasispecies complexity in HBV/HDV infection compared to HBV mono-infection may provide information on the interactions between these two viruses.
AIM:
To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta (CHD) and chronic HBV mono-infected patients.
METHODS:
Twenty-four untreated patients were included: 7/24 (29.2%) with HBeAg-negative chronic HBV infection (CI, previously termed inactive carriers), 8/24 (33.3%) with HBeAg-negative chronic hepatitis B (CHB) and 9/24 (37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels. The HBX 5' region [nucleotides (nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing (MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidence-based indices (number of haplotypes and number of mutations), abundance-based indices (Hill numbers of order 1 and 2), and functional indices (mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.
RESULTS:
CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL, interquartile range (IQR) 3.5-7.9] than CHD (3.4 logIU/mL, IQR 3-7.6) (P = n.s.) or CI (3.2 logIU/mL, IQR 2.3-3.5) (P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences (CHB 2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype.
CONCLUSION:
The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.Supported by the Instituto de Salud Carlos III, grants PI15/00856 and PI17/02233; co-financed by the European Regional Development Fund (ERDF
Analysis of hepatitis B virus preS1 variability and prevalence of the rs2296651 polymorphism in a Spanish population
Altres ajuts: Cofinanced by the European Regional Development Fund (ERDF); and the Gilead Fellowship Program, No. GLD14-00296.To determine the variability/conservation of the domain of hepatitis B virus (HBV) preS1 region that interacts with sodium-taurocholate cotransporting polypeptide (hereafter, NTCP-interacting domain) and the prevalence of the rs2296651 polymorphism (S267F, NTCP variant) in a Spanish population. Serum samples from 246 individuals were included and divided into 3 groups: patients with chronic HBV infection (CHB) (n = 41, 73% Caucasians), patients with resolved HBV infection (n = 100, 100% Caucasians) and an HBV-uninfected control group (n = 105, 100% Caucasians). Variability/conservation of the amino acid (aa) sequences of the NTCP-interacting domain, (aa 2-48 in viral genotype D) and a highly conserved preS1 domain associated with virion morphogenesis (aa 92-103 in viral genotype D) were analyzed by next-generation sequencing and compared in 18 CHB patients with viremia > 4 log IU/mL. The rs2296651 polymorphism was determined in all individuals in all 3 groups using an in-house real-time PCR melting curve analysis. The HBV preS1 NTCP-interacting domain showed a high degree of conservation among the examined viral genomes especially between aa 9 and 21 (in the genotype D consensus sequence). As compared with the virion morphogenesis domain, the NTCP-interacting domain had a smaller proportion of HBV genotype-unrelated changes comprising > 1% of the quasispecies (25.5% vs 31.8%), but a larger proportion of genotype-associated viral polymorphisms (34% vs 27.3%), according to consensus sequences from GenBank patterns of HBV genotypes A to H. Variation/conservation in both domains depended on viral genotype, with genotype C being the most highly conserved and genotype E the most variable (limited finding, only 2 genotype E included). Of note, proline residues were highly conserved in both domains, and serine residues showed changes only to threonine or tyrosine in the virion morphogenesis domain. The rs2296651 polymorphism was not detected in any participant. In our CHB population, the NTCP-interacting domain was highly conserved, particularly the proline residues and essential amino acids related with the NTCP interaction, and the prevalence of rs2296651 was low/null
ACE Score Identifies HBeAg-negative Inactive Carriers at a Single-point Evaluation, Regardless of HBV Genotype
HBV DNA; Hepatitis B virus; Inactive carrierADN del VHB; Virus de la hepatitis B; Portador inactivoADN del VHB; Virus de l'hepatitis B; Portador inactiuBackground and Aims
Hepatitis B virus (HBV) biomarkers have been used for a better categorization of patients, even though the lack of simple algorithms and the impact of genotypes limit their application. Our aim was to assess the usefulness of noninvasive markers for the identification of HBV inactive carriers (ICs) in a single-point evaluation and to design a predictive model for their identification.
Methods
This retrospective-prospective study included 343 consecutive HBeAg-negative individuals. Clinical, analytical, and virological data were collected, and a liver biopsy was performed if needed. Subjects were classified at the end of follow-up as ICs, chronic hepatitis B and gray zone.A predictive model was constructed, and validated by 1000-bootstrap samples.
Results
After 39 months of follow-up, 298 subjects were ICs, 36 were chronic hepatitis B CHB, and nine were gray zone. Eighty-nine (25.9%) individuals required a liver biopsy. Baseline HBV DNA hazard ratio (HR) 6.0, p<0.001), HBV core-related antigen (HBcrAg) (HR 6.5, p<0.001), and elastography (HR 4.6, p<0.001) were independently associated with the IC stage. The ACE score (HBV DNA, HBcrAg, elastography), obtained by bootstrapping, yielded an area under the receiver operating characteristics (AUROC) of 0.925 (95% CI: 0.880–0.970, p<0.001) for identification of ICs. The AUROC for genotype D was 0.95, 0.96 for A, 0.90 for E, and 0.88 for H/F. An ACE score of <1 had a positive predictive value of 99.5%, and a score ≤12 points had a diagnostic accuracy of 93.8%.
Conclusions
Low baseline HBV DNA, HBcrAg, and liver stiffness were independently associated with the IC phase. A score including those variables identified ICs at a single-point evaluation, and might be applied to implement less intensive follow-up strategies.This study received partial financial support from Instituto de Salud Carlos III (PI17/02233 and PI20/01692)
Inspecting the Ribozyme Region of Hepatitis Delta Virus Genotype 1: Conservation and Variability
Gene silencing; Quasispecies; RibozymeSilenciament gènic; Quasiespècie; RibozimaSilenciamiento de genes; Cuasiespecies; RibozimaThe hepatitis delta virus (HDV) genome has an autocatalytic region called the ribozyme, which is essential for viral replication. The aim of this study was to use next-generation sequencing (NGS) to analyze the ribozyme quasispecies (QS) in order to study its evolution and identify highly conserved regions potentially suitable for a gene-silencing strategy. HDV RNA was extracted from 2 longitudinal samples of chronic HDV patients and the ribozyme (nucleotide, nt 688–771) was analyzed using NGS. QS conservation, variability and genetic distance were analyzed. Mutations were identified by aligning sequences with their specific genotype consensus. The main relevant mutations were tested in vitro. The ribozyme was conserved overall, with a hyper-conserved region between nt 715–745. No difference in QS was observed over time. The most variable region was between nt 739–769. Thirteen mutations were observed, with three showing a higher frequency: T23C, T69C and C64 deletion. This last strongly reduced HDV replication by more than 1 log in vitro. HDV Ribozyme QS was generally highly conserved and was maintained during follow-up. The most conserved portion may be a valuable target for a gene-silencing strategy. The presence of the C64 deletion may strongly impair viral replication, as it is a potential mechanism of viral persistence.This research was funded by Institute of Health Carlos III, grant number PI20/01692 and co-financed by the European Regional Development Fund (ERDF), and by the European Regional Development Fund (ERDF)- Ministry of Economy, Industry and Competitiveness, grantRTI2018-101936-B-I00
Conservation and variability of hepatitis B core at different chronic hepatitis stages
Since it is currently not possible to eradicate hepatitis B virus (HBV) infection with existing treatments, research continues to uncover new therapeutic strategies. HBV core protein, encoded by the HBV core gene (HBC), intervenes in both structural and functional processes, and is a key protein in the HBV life cycle. For this reason, both the protein and the gene could be valuable targets for new therapeutic and diagnostic strategies. Moreover, alterations in the protein sequence could serve as potential markers of disease progression. To detect, by next-generation sequencing, HBC hyper-conserved regions that could potentially be prognostic factors and targets for new therapies. Thirty-eight of 45 patients with chronic HBV initially selected were included and grouped according to liver disease stage [chronic hepatitis B infection without liver damage (CHB, n = 16), liver cirrhosis (LC, n = 5), and hepatocellular carcinoma (HCC, n = 17)]. HBV DNA was extracted from patients' plasma. A region between nucleotide (nt) 1863 and 2483, which includes HBC, was amplified and analyzed by next-generation sequencing (Illumina MiSeq platform). Sequences were genotyped by distance-based discriminant analysis. General and intergroup nt and amino acid (aa) conservation was determined by sliding window analysis. The presence of nt insertion and deletions and/or aa substitutions in the different groups was determined by aligning the sequences with genotype-specific consensus sequences. Three nt (nt 1900-1929, 2249-2284, 2364-2398) and 2 aa (aa 117-120, 159-167) hyper-conserved regions were shared by all the clinical groups. All groups showed a similar pattern of conservation, except for five nt regions (nt 1946-1992, 2060-2095, 2145-2175, 2230-2250, 2270-2293) and one aa region (aa 140-160), where CHB and LC, respectively, were less conserved (P < 0.05). Some group-specific conserved regions were also observed at both nt (2306-2334 in CHB and 1935-1976 and 2402-2435 in LC) and aa (between aa 98-103 in CHB and 28-30 and 51-54 in LC) levels. No differences in insertion and deletions frequencies were observed. An aa substitution (P79Q) was observed in the HCC group with a median (interquartile range) frequency of 15.82 (0-78.88) vs 0 (0-0) in the other groups (P < 0.05 vs CHB group). The differentially conserved HBC and HBV core protein regions and the P79Q substitution could be involved in disease progression. The hyper-conserved regions detected could be targets for future therapeutic and diagnostic strategies
Sophisticated viral quasispecies with a genotype-related pattern of mutations in the hepatitis B X gene of HBeAg-ve chronically infected patients
Haplotipos; Enfermedades infecciosas; MutaciónHaplotips; Enfermetats infeccioses; MutacióHaplotypes; Infectious diseases; MutationPatients with HBeAg-negative chronic infection (CI) have not been extensively studied because of low viremia. The HBx protein, encoded by HBX, has a key role in viral replication. Here, we analyzed the viral quasispecies at the 5′ end of HBX in CI patients and compared it with that of patients in other clinical stages. Fifty-eight HBeAg-negative patients were included: 16 CI, 19 chronic hepatitis B, 16 hepatocellular carcinoma and 6 liver cirrhosis. Quasispecies complexity and conservation were determined in the region between nucleotides 1255 and 1611. Amino acid changes detected were tested in vitro. CI patients showed higher complexity in terms of mutation frequency and nucleotide diversity and higher quasispecies conservation (p < 0.05). A genotype D-specific pattern of mutations (A12S/P33S/P46S/T36D-G) was identified in CI (median frequency, 81.7%), which determined a reduction in HBV DNA release of up to 1.5 log in vitro. CI patients showed a more complex and conserved viral quasispecies than the other groups. The genotype-specific pattern of mutations could partially explain the low viremia observed in these patients.This study was supported by grants from the Institute of Health Carlos III (grant PI15/00856 and PI18/01436) and co-financed by the European Regional Development Fund (ERDF)
Aula de memoria. Recursos didácticos para recuperar la historia de los olvidados.
Depto. de Didáctica de las Ciencias Experimentales , Sociales y MatemáticasFac. de EducaciónFALSEVicerrectorado de Calidad, UCMsubmitte
High-resolution hepatitis C virus subtyping using NS5B deep sequencing and phylogeny, an alternative to current methods
HepatitisCvirus(HCV)is classified into seven major genotypesand67 subtypes. Recent studies haveshownthat inHCVgenotype 1-infected
patients, response rates to regimens containingdirect-acting antivirals(DAAs)are subtype dependent. Currently available genotypingmethods
have limited subtyping accuracy.Wehave evaluated theperformanceof adeep-sequencing-basedHCVsubtyping assay, developed for the
454/GS-Junior platform, in comparisonwith thoseof two commercial assays (VersantHCVgenotype 2.0andAbbott Real-timeHCVGenotype
II)andusingdirectNS5Bsequencing as a gold standard (direct sequencing), in 114 clinical specimenspreviously tested by first-generation
hybridization assay (82 genotype 1and32 with uninterpretable results). Phylogenetic analysis of deep-sequencing reads matched subtype
1 callingbypopulation Sanger sequencing(69%1b,31%1a) in 81 specimensandidentified amixed-subtype infection (1b/3a/1a) in one sample.
Similarly,amongthe 32previously indeterminate specimens, identical genotypeandsubtype results were obtained by directanddeep
sequencing in all but four samples with dual infection. In contrast, both VersantHCVGenotype 2.0andAbbott Real-timeHCVGenotype II
failed subtype 1 calling in 13 (16%) samples eachandwere unable to identify theHCVgenotype and/or subtype inmore than half of the nongenotype
1 samples.Weconcluded that deep sequencing ismore efficient forHCVsubtyping than currently available methodsandallows
qualitative identificationofmixed infectionsandmay bemorehelpfulwith respect to informing treatment strategies withnewDAA-containing
regimens across allHCVsubtypesThis study has been supported by CDTI (Centro para el Desarrollo Tecnológico
Industrial), Spanish Ministry of Economics and Competitiveness
(MINECO), IDI-20110115; MINECO projects SAF 2009-10403; and
also by the Spanish Ministry of Health, Instituto de Salud Carlos III (FIS)
projects PI10/01505, PI12/01893, and PI13/00456. CIBERehd is funded
by the Instituto de Salud Carlos III, Madrid, Spain. Work at CBMSO was
supported by grant MINECO-BFU2011-23604, FIPSE, and Fundación
Ramón Areces.
X. Forns received unrestricted grant support from Roche and has
acted as advisor for MSD, Gilead, and Abbvie. M. Alvarez-Tejado, J. Gregori,
and J. M. Muñoz work in Roche Diagnostic
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