101 research outputs found
Expression of Human CD4 and chemokine receptors in cotton rat cells confers permissiveness for productive HIV infection
<p>Abstract</p> <p>Background</p> <p>Current small animal models for studying HIV-1 infection are very limited, and this continues to be a major obstacle for studying HIV-1 infection and pathogenesis, as well as for the urgent development and evaluation of effective anti-HIV-1 therapies and vaccines. Previously, it was shown that HIV-1 can infect cotton rats as indicated by development of antibodies against all major proteins of the virus, the detection of viral cDNA in spleen and brain of challenged animals, the transmission of infectious virus, albeit with low efficiency, from animal to animal by blood, and an additional increase in the mortality in the infected groups.</p> <p>Results</p> <p>Using <it>in vitro </it>experiments, we now show that cotton rat cell lines engineered to express human receptor complexes for HIV-1 (hCD4 along with hCXCR4 or hCCR5) support virus entry, viral cDNA integration, and the production of infectious virus.</p> <p>Conclusion</p> <p>These results further suggest that the development of transgenic cotton rats expressing human HIV-1 receptors may prove to be useful small animal model for HIV infection.</p
Genetic risk factors for Parkinson’s disease in Ukraine
The paper focuses on the genetic risk factors for Parkinson’s disease (PD) such as polymorphisms in genes CYP1A1, GSTM1 and APOE. A total number of 516 people were examined. 300 persons were in the control group (mean age 67,0 ± 0,4 years; 200 males and 100 females) and 216 persons were patients with PD (mean age 65,0 ± 0,7 years, 116 males and 100 females). Whole blood samples collected from each person were genotyped using PCR-RFLP. Amplification and restriction results were assessed by conducting vertical agarose gel electrophoresis. The study analyzed marker с.2452C>A in the CYP1A1 gene. In the control group, allele C frequency was 0.79, and allele A frequency – 0.21. Genotype frequencies were: CC – 0.61, AC – 0.36, AA – 0.03. In the group of patients alleles C and A frequencies were 0.64 and 0.36 correspondingly. Genotype frequencies were: CC – 0.35, AC – 0.58, AA – 0.07. There was a significant difference between both groups in allele A frequency. It is considered that 0/0 genotype for the GSTM1 gene is a risk factor for PD. In the controls, +/+ and 0/0 genotypes frequencies were 0.67 and 0.33 correspondingly. In the group of patients +/+ genotype frequency was 0.55 and 0/0 genotype frequency – 0.45. The difference was statistically significant. In the control group genotype frequencies for the АРОЕ gene were 0.715 (Е3/Е3), 0.077 (Е3/Е4), 0.009 (Е4/Е4), 0.167 (Е2/Е3), 0.031 (Е2/Е4) and 0.000 (Е2/Е2). In the group of patients with PD they were 0.634 (Е3/Е3), 0.148 (Е3/Е4), 0.032 (Е4/Е4), 0.157 (Е2/Е3), 0.023 (Е2/Е4) and 0.000 (Е2/Е2). Е3/Е4 genotype frequency was significantly higher in the group of patients with PD than in the control group. Pathogenic allele с.2452C>A of the CYP1A1 gene is associated with increased risk of PD (OR = 1.72). 0/0 genotype carriers have higher risk to develop PD (OR = 1.72). Allele έ4 of the АРОЕ gene may be associated with increased risk of PD. Risk of the disease is higher in έ2 allele carriers (OR = 2.35) and έ4 allele carriers (OR=1.97). People with genotype Е4/Е4 have chances to be affected by PD 3.48 times higher (OR = 3.48). Associations revealed in the different human populations between genetic factors and PD may vary that is associated with the genetic heterogeneity and proportion of environmental factors which affect people. Despite the results are sometimes controversial, they can be helpful in developing DNA-tests for early diagnosis of PD
Language complexity in on-line health information retrieval
The number of people searching for on-line health information has been steadily growing over the years so it is crucial to understand their specific requirements in order to help them finding easily and quickly the specific in-formation they are looking for. Although generic search engines are typically used by health information seekers as the starting point for searching information, they have been shown to be limited and unsatisfactory because they make generic searches, often overloading the user with the provided amount of results. Moreover, they are not able to provide specific information to different types of users. At the same time, specific search engines mostly work on medical literature and provide extracts from medical journals that are mainly useful for medical researchers and experts but not for non-experts.
A question then arises: Is it possible to facilitate the search of on-line health/medical information based on specific user requirements? In this pa-per, after analysing the main characteristics and requirements of on-line health seeking, we provide a first answer to this question by exploiting the Web structured data for the health domain and presenting a system that allows different types of users, i.e., non-medical experts and medical experts, to retrieve Web pages with language complexity levels suitable to their expertise. Furthermore, we apply our methodology to the results of a generic search engine, such as Google, in order to re-rank them and provide different users with the proper health/medical Web pages in terms of language complexity
Norovirus Recombination in ORF1/ORF2 Overlap
Norovirus (NoV) genogroups I and II (GI and GII) are now recognized as the predominant worldwide cause of outbreaks of acute gastroenteritis in humans. Three recombinant NoV GII isolates were identified and characterized, 2 of which are unrelated to any previously published recombinant NoV. Using data from the current study, published sequences, database searches, and molecular techniques, we identified 23 recombinant NoV GII and 1 recombinant NoV GI isolates. Analysis of the genetic relationships among the recombinant NoV GII isolates identified 9 independent recombinant sequences; the other 14 strains were close relatives. Two of the 9 independent recombinant NoV were closely related to other recombinants only in the polymerase region, and in a similar fashion 1 recombinant NoV was closely related to another only in the capsid region. Breakpoint analysis of recombinant NoV showed that recombination occurred in the open reading frame (ORF)1/ORF2 overlap. We provide evidence to support the theory of the role of subgenomic RNA promoters as recombination hotspots and describe a simple mechanism of how recombination might occur in NoV
Vaccine antigens modulate the innate response of monocytes to Al(OH)3.
Aluminum-based adjuvants have widely been used in human vaccines since 1926. In the absence of antigens, aluminum-based adjuvants can initiate the inflammatory preparedness of innate cells, yet the impact of antigens on this response has not been investigated so far. In this study, we address the modulating effect of vaccine antigens on the monocyte-derived innate response by comparing processes initiated by Al(OH)3 and by Infanrix, an Al(OH)3-adjuvanted trivalent combination vaccine (DTaP), containing diphtheria toxoid (D), tetanus toxoid (T) and acellular pertussis (aP) vaccine antigens. A systems-wide analysis of stimulated monocytes was performed in which full proteome analysis was combined with targeted transcriptome analysis and cytokine analysis. This comprehensive study revealed four major differences in the monocyte response, between plain Al(OH)3 and DTaP stimulation conditions: (I) DTaP increased the anti-inflammatory cytokine IL-10, whereas Al(OH)3 did not; (II) Al(OH)3 increased the gene expression of IFNγ, IL-2 and IL-17a in contrast to the limited induction or even downregulation by DTaP; (III) increased expression of type I interferons-induced proteins was not observed upon DTaP stimulation, but was observed upon Al(OH)3 stimulation; (IV) opposing regulation of protein localization pathways was observed for Al(OH)3 and DTaP stimulation, related to the induction of exocytosis by Al(OH)3 alone. This study highlights that vaccine antigens can antagonize Al(OH)3-induced programming of the innate immune responses at the monocyte level
Rapid Evolution of Pandemic Noroviruses of the GII.4 Lineage
Over the last fifteen years there have been five pandemics of norovirus (NoV) associated gastroenteritis, and the period of stasis between each pandemic has been progressively shortening. NoV is classified into five genogroups, which can be further classified into 25 or more different human NoV genotypes; however, only one, genogroup II genotype 4 (GII.4), is associated with pandemics. Hence, GII.4 viruses have both a higher frequency in the host population and greater epidemiological fitness. The aim of this study was to investigate if the accuracy and rate of replication are contributing to the increased epidemiological fitness of the GII.4 strains. The replication and mutation rates were determined using in vitro RNA dependent RNA polymerase (RdRp) assays, and rates of evolution were determined by bioinformatics. GII.4 strains were compared to the second most reported genotype, recombinant GII.b/GII.3, the rarely detected GII.3 and GII.7 and as a control, hepatitis C virus (HCV). The predominant GII.4 strains had a higher mutation rate and rate of evolution compared to the less frequently detected GII.b, GII.3 and GII.7 strains. Furthermore, the GII.4 lineage had on average a 1.7-fold higher rate of evolution within the capsid sequence and a greater number of non-synonymous changes compared to other NoVs, supporting the theory that it is undergoing antigenic drift at a faster rate. Interestingly, the non-synonymous mutations for all three NoV genotypes were localised to common structural residues in the capsid, indicating that these sites are likely to be under immune selection. This study supports the hypothesis that the ability of the virus to generate genetic diversity is vital for viral fitness
Protein docking prediction using predicted protein-protein interface
<p>Abstract</p> <p>Background</p> <p>Many important cellular processes are carried out by protein complexes. To provide physical pictures of interacting proteins, many computational protein-protein prediction methods have been developed in the past. However, it is still difficult to identify the correct docking complex structure within top ranks among alternative conformations.</p> <p>Results</p> <p>We present a novel protein docking algorithm that utilizes imperfect protein-protein binding interface prediction for guiding protein docking. Since the accuracy of protein binding site prediction varies depending on cases, the challenge is to develop a method which does not deteriorate but improves docking results by using a binding site prediction which may not be 100% accurate. The algorithm, named PI-LZerD (using Predicted Interface with Local 3D Zernike descriptor-based Docking algorithm), is based on a pair wise protein docking prediction algorithm, LZerD, which we have developed earlier. PI-LZerD starts from performing docking prediction using the provided protein-protein binding interface prediction as constraints, which is followed by the second round of docking with updated docking interface information to further improve docking conformation. Benchmark results on bound and unbound cases show that PI-LZerD consistently improves the docking prediction accuracy as compared with docking without using binding site prediction or using the binding site prediction as post-filtering.</p> <p>Conclusion</p> <p>We have developed PI-LZerD, a pairwise docking algorithm, which uses imperfect protein-protein binding interface prediction to improve docking accuracy. PI-LZerD consistently showed better prediction accuracy over alternative methods in the series of benchmark experiments including docking using actual docking interface site predictions as well as unbound docking cases.</p
Mobilise-D insights to estimate real-world walking speed in multiple conditions with a wearable device
This study aimed to validate a wearable device’s walking speed estimation pipeline, considering complexity, speed, and walking bout duration. The goal was to provide recommendations on the use of wearable devices for real-world mobility analysis. Participants with Parkinson’s Disease, Multiple Sclerosis, Proximal Femoral Fracture, Chronic Obstructive Pulmonary Disease, Congestive Heart Failure, and healthy older adults (n = 97) were monitored in the laboratory and the real-world (2.5 h), using a lower back wearable device. Two walking speed estimation pipelines were validated across 4408/1298 (2.5 h/laboratory) detected walking bouts, compared to 4620/1365 bouts detected by a multi-sensor reference system. In the laboratory, the mean absolute error (MAE) and mean relative error (MRE) for walking speed estimation ranged from 0.06 to 0.12 m/s and − 2.1 to 14.4%, with ICCs (Intraclass correlation coefficients) between good (0.79) and excellent (0.91). Real-world MAE ranged from 0.09 to 0.13, MARE from 1.3 to 22.7%, with ICCs indicating moderate (0.57) to good (0.88) agreement. Lower errors were observed for cohorts without major gait impairments, less complex tasks, and longer walking bouts. The analytical pipelines demonstrated moderate to good accuracy in estimating walking speed. Accuracy depended on confounding factors, emphasizing the need for robust technical validation before clinical application.
Trial registration: ISRCTN – 12246987
Experimental detection of short regulatory motifs in eukaryotic proteins: tips for good practice as well as for bad
It has become clear in outline though not yet in detail how cellular regulatory and signalling systems are constructed. The essential machines are protein complexes that effect regulatory decisions by undergoing internal changes of state. Subcomponents of these cellular complexes are assembled into molecular switches. Many of these switches employ one or more short peptide motifs as toggles that can move between one or more sites within the switch system, the simplest being on-off switches. Paradoxically, these motif modules (termed short linear motifs or SLiMs) are both hugely abundant but difficult to research. So despite the many successes in identifying short regulatory protein motifs, it is thought that only the “tip of the iceberg” has been exposed. Experimental and bioinformatic motif discovery remain challenging and error prone. The advice presented in this article is aimed at helping researchers to uncover genuine protein motifs, whilst avoiding the pitfalls that lead to reports of false discovery. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12964-015-0121-y) contains supplementary material, which is available to authorized users
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