Genome-wide evolutionary dynamics of influenza B viruses on a global scale

The global-scale epidemiology and genome-wide evolutionary dynamics of influenza B remain poorly understood compared with influenza A viruses. We compiled a spatio-temporally comprehensive dataset of influenza B viruses, comprising over 2,500 genomes sampled worldwide between 1987 and 2015, including 382 newly-sequenced genomes that fill substantial gaps in previous molecular surveillance studies. Our contributed data increase the number of available influenza B virus genomes in Europe, Africa and Central Asia, improving the global context to study influenza B viruses. We reveal Yamagata-lineage diversity results from co-circulation of two antigenically-distinct groups that also segregate genetically across the entire genome, without evidence of intra-lineage reassortment. In contrast, Victoria-lineage diversity stems from geographic segregation of different genetic clades, with variability in the degree of geographic spread among clades. Differences between the lineages are reflected in their antigenic dynamics, as Yamagata-lineage viruses show alternating dominance between antigenic groups, while Victoria-lineage viruses show antigenic drift of a single lineage. Structural mapping of amino acid substitutions on trunk branches of influenza B gene phylogenies further supports these antigenic differences and highlights two potential mechanisms of adaptation for polymerase activity. Our study provides new insights into the epidemiological and molecular processes shaping influenza B virus evolution globally

The impact of site specificity and needle manipulation on changes to pain pressure threshold following manual acupuncture: A controlled study

Objectives: To investigate the contribution of two principal features that underlie traditional Chinese acupuncture: site specificity and application of needle manipulation. Design: Thirteen volunteers completed a randomised, dual blind (subject and assessor) repeated measures study involving five interventions. Pressure pain threshold (PPT) was measured with an algometer, before and after intervention at 10 sites (acupoints and nonacupoints) across the body. Interventions: Deep needling, with or without manual needle rotation, applied to the acupoint Large Intestine 4 (LI4) or to a nonacupoint located on the medial side of the second metacarpal. Inactive laser to LI4 was used as a control. All interventions were administered for 21 min. Main outcome measures: Percentage change in PPT from preintervention baseline at the 10 sites during the 18 min immediately following intervention. Results: Statistically significant increases from preintervention PPT means were obtained at all 10 sites following needling of LI4 with manipulation compared with one site after needling LI4 without manipulation. Needling the nonacupoint led to statistically significant increases at six sites when manipulation was present compared with none in the absence of manipulation. No significant changes in mean PPT followed inactive laser. Needling LI4 with manipulation produced mean increases that were statistically significantly greater than those for the other interventions with one exception: needling the nonacupoint with manipulation was as effective as needling LI4 with manipulation at one measurement site only. Conclusions: Both manipulation and site of needling contributed significantly to the elevation of PPT following acupuncture. Distribution of effects on PPT did not support either neural segmental or Traditional Chinese Medicine channel theories. Psychological and physiological nonspecific effects appeared to play a minimal role in changes to PPT. © 2003 Elsevier Science Ltd. All rights reserved