3,687 research outputs found
The impact of joint aches, pain and stiffness post primary breast cancer treatment on psychosocial health: A case controlled, cross sectional study
No full textTHE EFFECT OF DIFFERENT TYPES AND DOSES OF ALPHA IFN IN THE TREATMENT OF CHRONIC HEPATITIS C
No full textStructural constraints on RNA virus evolution
No full textThe recently discovered hepatitis G virus (HGV) or GB virus C (GBV-C) is widely distributed in human populations, and homologues such as HGV/GBV-CCPZ and GBV-A are found in a variety of different primate species. Both epidemiological and phylogenetic analyses support the hypothesis that GB viruses coevolved with their primate hosts, although their degree of sequence similarity appears incompatible with the high rate of sequence change of HGV/GBV-C over short observation periods. Comparison of complete coding sequences (8,500 bases) of different genotypes of HGV/GBV-C showed an excess of invariant synonymous sites (at 23% of all codons) compared with the frequency expected by chance (10%). To investigate the hypothesis that RNA secondary-structure formation through internal base pairing limited sequence variability at these sites, an algorithm was developed to detect covariant sites among HGV/GBV-C sequences of different genotypes. At least 35 covariant sites that were spatially associated with potential stem-loop structures were detected, whose positions correlated with positions in the genome that showed reductions in synonymous variability. Although the functional roles of the predicted secondary structures remain unclear, the restriction of sequence change imposed by secondary-structure formation provides a mechanism for differences in net rate of accumulation of nucleotide substitutions at different sites. However, the resulting disparity between short- and long-term rates of sequence change of HGV/GBV-C violates the assumptions of the "molecular clock." This places a major restriction on the use of nucleotide or amino acid sequence comparisons to calculate times of divergence of other viruses evolving under the same structural constraints as GB viruses
Detection of genome-scale ordered RNA structure (GORS) in genomes of positive-stranded RNA viruses:Implications for virus evolution and host persistence
No full textDiscrete RNA secondary and higher-order structures, typically local in extent, play a fundamental role in RNA virus replication. Using new bioinformatics analysis methods, we have identified genome-scale ordered RNA structure (GORS) in many genera and families of positive-strand animal and plant RNA viruses. There was remarkably variability between genera that possess this characteristic; for example, hepaciviruses in the family Flaviviridae show evidence for extensive internal base-pairing throughout their coding sequences that was absent in both the related pestivirus and flavivirus genera. Similar genus-associated variability was observed in the Picornaviridae, the Caliciviridae, and many plant virus families. The similarity in replication strategies between genera in each of these families rules out a role for GORS in a fundamentally conserved aspect of this aspect of the virus life cycle. However, in the Picornaviridae, Flaviviridae, and Caliciviridae, the existence of GORS correlated strongly with the ability of each genus to persist in their natural hosts. This raises the intriguing possibility of a role for GORS in the modulation of innate intracellular defense mechanisms (and secondarily, the acquired immune system) triggered by double-stranded RNA, analogous in function to the expression of structured RNA transcripts by large DNA viruses. Irrespective of function, the observed evolutionary conservation of GORS in many viruses imposes a considerable constraint on genome plasticity and the consequent narrowing of sequence space in which neutral drift can occur. These findings potentially reconcile the rapid evolution of RNA viruses over short periods with the documented examples of extreme conservatism evident from their intimate coevolution with their hosts
Ocorrência da podridão floral dos citros (Coletotrichum acutatum, Simmonds), em diferentes combinações de copa e porta-enxerto.
No full textA doença Podridão Floral dos Citros (PFC) ou estrelinha como é conhecida pelos produtores é causada pelo fungo Colletotrichum acutatum, Simmonds que produz lesões de coloração alaranjada ou ferruginosa nos botões florais ou nas pétalas, infectando posteriormente o estilo que se desprende, ficando aderidos aos ramos os receptáculos persistentes da flor. Este trabalho objetivou avaliar a incidência do fungo C. acutatum, Simmonds, em flores de copa de lima ácida Tahiti enxertada sobre cinco diferentes porta-enxertos.PDF. 089_1
Functional self-efficacy, perceived gait ability and perceived exertion in walking performance of individuals with low back pain
No full textThe purpose of this study was to examine psychological and perceptual factors that influence walking in individuals with low back pain (LBP). In Study 1 59 subjects with LBP recruited from an orthopedic surgeon participated. Perceived gait ability was measured with the Distorted Ambulation subscale of Pain Behavior Checklist (DAS-PBCL). The psychological factor of functional self-efficacy (FSE) was assessed on the FSE scale. These scales were completed before performing a 50-foot speed walk (50 FT WALK) and a 5-minute distance walk (5 MIN WALK) tests. DAS-PBCL had stronger correlations with walking performance (r = 0.11 to 0.58) than FSE (r = 0.03 to 0.49). DAS-PBCL had a stronger relationship with 50 FT WALK ( r = 0.18 to 0.58) than 5 MIN WALK (r = 0.11 to 0.50). In Study 2 48 healthy pain-free subjects and an independent sample of 40 subjects with LBP referred from an orthopedic surgeon participated. They completed the 5 MIN WALK followed by the modified Borg's rating of perceived exertion scale (CR10). Subjects with LBP walked a significantly shorter distance (t = 4.69, p<.005) but perceived a similar amount of exertion (Mann-Whitney U = 861.5, p = .40) compared with those without LBP. Perceived gait ability appears to account for more variability in walking performance than functional self-efficacy of walking in individuals with LBP. Perceived gait ability, in particular, accounted for more variance in walking speed than in walking endurance. Individuals with LBP also experience more exertion during walking than those without LBP. These results suggest that clinicians may need to consider patients' perceptions of gait ability and exertion when assessing walking performance in patients with LBP
CLINICAL EVALUATION OF A SINGLE REACTION, DIAGNOSTIC PCR ASSAY FOR THE DETECTION OF HEPATITIS C VIRUS (HCV) RNA
No full textBACKGROUND/AIMS: In the past few years the detection of HCV-RNA by polymerase chain reaction has become a well-established diagnostic tool for patients with chronic hepatitis C. However, the lack of reproducible results between laboratories and the relatively high proportion of false-positive results, has indicated the need for a standardized and reliable polymerase chain reaction assay. In the present study we have analyzed the performance of a commercial, HCV-RNA polymerase chain reaction assay based on a single, combined reverse transcription and amplification reaction and on the use of Uracil-N-glycosilase to prevent carry-over contamination (Amplicor HCV, Roche Molecular Systems).
METHODS: In this assay the amplification products are detected in microwell plates using biotinylated primer and the HRP avidin colorimetric system. Serum samples collected from 446 patients, including 181 with chronic active hepatitis C, 50 with autoimmune chronic hepatitis, 117 in hemodialysis, 30 asymptomatic carriers of anti-HCV and 68 with indeterminate serology (RIBA indeterminate results), as well as from 121 controls were tested with the commercial, single-step assay and with nested polymerase chain reaction. Both techniques use primers located within the 5' non-coding region of the HCV genome.
RESULTS: In all cases a good concordance was observed between the commercial, single-step assay and nested polymerase chain reaction which, for patients with chronic active hepatitis, showed a sensitivity and specificity of 100% and 99.3% for the former and of 98.8% and 100% for the latter, when compared to clinical diagnosis taken as the gold standard. Most of the 11 discordant samples were seen in the group of RIBA-indeterminate cases and in patients with chronic active hepatitis C. Further analysis of these cases, based on repeat testing and clinical data showed that 64% and 36% of the discrepancies were due, respectively, to nested polymerase chain reaction and Amplicor inconsistent reactions. In hemodialyzed patients, patients with autoimmune hepatitis and asymptomatic carriers of anti-HCV, both assays produced results which were consistent with the clinical diagnosis. In the former group, polymerase chain reaction was able to identify the presence of active viral replication in some antibody negative samples.
CONCLUSIONS: Taken together, these results indicate that the commercial, single-step polymerase chain reaction assay has the same clinical sensitivity and specificity as nested polymerase chain reaction and that, because of its simplified procedures and fast turn-around time, it may be a valuable test for routine diagnostic applications
Supplemental Material, DS1_CPCJ_10.1177_1055665618760898 - Neonatal Macroglossia: Demographics, Cost of Care, and Associated Comorbidities
No full textSupplemental Material, DS1_CPCJ_10.1177_1055665618760898 for Neonatal Macroglossia: Demographics, Cost of Care, and Associated Comorbidities by Jonathan C. Simmonds, Anju K. Patel, Nicholas R. Mildenhall, Nicholas S. Mader, and Andrew R. Scott in The Cleft Palate-Craniofacial Journal</p
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