Moving instead of asking? Performance-based tests and BASFI-questionnaire measure different aspects of physical function in ankylosing spondylitis

Introduction

Ankylosing Spondylitis (AS) is characterised by limitations in physical function. The Bath Ankylosing Spondylitis Functional Index (BASFI) is considered to be the gold-standard to assess physical function in AS patients. However, the BASFI questionnaire is a self-reported outcome measure and susceptible to subjective interpretation (under- or over-estimation). More objective outcome measures, like performance-based tests, could provide an objective outcome measurement for the evaluation of limitations in physical function. Therefore, the primary aim of this study was to determine the association between performance-based measures and the BASFI questionnaire.

Methods

In this cross-sectional study 126 AS patients completed the BASFI questionnaire and eight performance-based tests based on BASFI-items. Each test received three scores: one for performance (time or points) and a score for exertion and pain experienced during performance (using modified Borg-scale and VAS 0-100 mm, respectively). Linear regression analyses were used to assess the associations between the BASFI questionnaire and performance-based tests.

Results

The univariable association between performance and BASFI-score was moderate with a R-square of 0.31 and Beta of 0.56 (p's < 0.05). In a multivariable analysis, the association between performance, exertion and pain on the one hand and BASFI-score on the other was assessed; R-square increased to 0.54: the Beta's for exertion and pain during performance were 0.38 and 0.26, respectively; the Beta for performance decreased to 0.19 (p's < 0.05).

Conclusions

This study demonstrates that alongside actual performance, patients seem to incorporate exertion and pain in their assessment of perceived physical function on the BASFI questionnaire. Performance-based tests could provide an objective outcome measurement for the evaluation of physical function and give relevant new information in addition to the BASFI questionnaire.     

Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows

During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside calls positively correlate with the area of the burrow entrance and the depth of the burrow, respectively. When given a choice between outside and inside calls played back alternately, more than 70 per cent of the females (33/47) chose inside calls. These results demonstrate that males of this species faithfully advertise whether or not they possess a nest to potential mates by vocal communication, which probably facilitates optimal mate selection by females. These results revealed a novel function of advertisement calls, which is consistent with the wide variation in both call complexity and social behaviour within amphibians.     

Designing a strategy to implement cost-effective blood transfusion management in elective hip and knee arthroplasties: A study protocol

ABSTRACT: BACKGROUND: Total hip and knee arthroplasties are two of the most commonly performed procedures in orthopedic surgery. Different blood-saving measures (BSMs) are used to reduce the often-needed allogenic blood transfusions in these procedures. A recent large randomized controlled trial showed it is not cost effective to use the BSMs of erythropoietin and perioperative autologous blood salvage in elective primary hip and knee arthroplasties. Despite dissemination of these study results, medical professionals keep using these BSMs. To actually change practice, an implementation strategy is needed that is based on a good understanding of target groups and settings and the psychological constructs that predict behavior of medical professionals. However, detailed insight into these issuses is lacking. Therefore, this study aims to explore which groups of professionals should be targeted at which settings, as well as relevant barriers and facilitators that should be taken into acount in the strategy to implement evidence-based, cost-effective blood transfusion management and to de-implement BSMs. METHODS: The study consists of three phases. First, a questionnaire survey among all Dutch orthopedic hospital departments and independent treatment centers (n?=?99) will be conducted to analyze current blood management practice. Second, semistructured interviews will be held among 10 orthopedic surgeons and 10 anesthesiologists to identify barriers and facilitators that are relevant for the uptake of cost-effective blood transfusion management. Interview questions will be based on the Theoretical Domains Interview framework. The interviews will be followed by a questionnaire survey among 800 medical professionals in orthopedics and anesthesiology (400 professionals per discipline) in which the identified barriers and facilitators will be ranked by frequency and importance. Finally, an implementation strategy will be developed based on the results from the previous phases, using principles of intervention mapping and an expert panel. DISCUSSION: The developed strategy for cost-effective blood transfusion management by de-implementing BSMs is likely to reduce costs for elective hip and knee arthroplasties. In addition, this study will lead to generalized knowledge regarding relevant factors for the de-implementation of non-cost-effective interventions and insight in the differences between implementation and de-implementation strategies.     

Heterospecific Acoustic Interference: Effects on Calling in Oophaga pumilio

Call rate suppression is a common short-term solution for avoiding acoustic interference in animals. It has been widely documented between and within frog species, but the effects of non-anuran calling on frog vocalizations are less well known. Heterospecific acoustic interference on the calling of male Oophaga pumilio (formerly Dendrobates pumilio) was studied in a lowland, wet tropical forest in SE Nicaragua. Acoustic playback experiments were conducted to characterize the responses of O. pumilio males to interfering calls of cicadas, two species of crickets, and a sympatric dendrobatid frog, Phyllobates lugubris. Call rate, call bout duration, percent of time calling, dominant frequency, and latency to first-call were analyzed. Significant call rate suppression was observed during all stimulus playbacks, yet no significant differences were found in spontaneous call rates during pre- and postplayback trials. Dominant frequency significantly decreased after P. lugubris playback and first-call latency significantly decreased in response to both cicada and tree cricket playbacks. These results provide robust evidence that O. pumilio males can dynamically modify their calling pattern in unique ways, depending on the source of the heterospecific acoustic interference.     

"Silent" sites in Drosophila genes are not neutral: evidence of selection among synonymous codons

The patterns of synonymous codon usage in 91 Drosophila melanogaster genes have been examined. Codon usage varies strikingly among genes. This variation is associated with differences in G+C content at silent sites, but (unlike the situation in mammalian genes) these differences are not correlated with variation in intron base composition and so are not easily explicable in terms of mutational biases. Instead, those genes with high G+C content at silent sites, resulting from a strong "preference" for a particular subset of the codons that are mostly C- ending, appear to be the more highly expressed genes. This suggests that G+C content is reduced in sequences where selective constraints are weaker, as indeed seen in a pseudogene. These and other data discussed are consistent with the effects of translational selection among synonymous codons, as seen in unicellular organisms. The existence of selective constraints on silent substitutions, which may vary in strength among genes, has implications for the use of silent molecular clocks.      

The rate of synonymous substitution in enterobacterial genes is inversely related to codon usage bias

Genes sequences from Escherichia coli, Salmonella typhimurium, and other members of the Enterobacteriaceae show a negative correlation between the degree of synonymous-codon usage bias and the rate of nucleotide substitution at synonymous sites. In particular, very highly expressed genes have very biased codon usage and accumulate synonymous substitutions very slowly. In contrast, there is little correlation between the degree of codon bias and the rate of protein evolution. It is concluded that both the rate of synonymous substitution and the degree of codon usage bias largely reflect the intensity of selection at the translational level. Because of the high variability among genes in rates of synonymous substitution, separate molecular clocks of synonymous substitution might be required for different genes.      

Stimulation of Cultured Melanocytes in Medium Containing a Serum Substitute: Ultroser-G

Melanocyte cultures were established and maintained routinely in Ham's F-10 medium containing 12-O-tetradecanoyl-phorbol-13-acetate (TPA), isobutylmethylxanthine (IBMX), cholera toxin (CT) and fetal calf serum (FCS). Three serum substitutes (Ultroser-G, Nutridoma-Hu and Nutricyte-H) were tested in order to obtain a medium without FCS having a more constant composition. Melanocyte proliferation was examined in long-term culture experiments by in situ cell counts at different periods of time. Only with Ultroser-G (1-2%) was the proliferation of melanocytes maintained without both FCS and CT, whereas the addition of the other two serum substitutes resulted in stabilization of melanocyte densities in the cultures up to 28 days. In the medium containing 1% Ultroser-G and IBMX without TPA minimal or no increases in melanocyte density were found. Addition of basic fibroblast growth factor (bFGF, 1 ng/ml) to the medium without TPA resulted in a partial restimulation of growth in different experiments. In this system with 1% Ultroser-G and 1 ng/ml bFGF, IBMX could also be replaced by other factors (dbcAMP LTC4 and a purified form of α-melanocyte stimulating hormone). The culture medium with 1% Ultroser-G containing TPA and IBMX is now used for routine melanocyte culture. In this medium TPN/IBMX can easily be replaced by bFGF/dbcAMP with optimal growth stimulation. The combination bFGF/α-MSH and other more physiological stimulators offers an alternative to study responses of melanocytes in culture with respect to proliferation, metabolism, and phenotype.     

Molecular evolution of mammalian aquaporin-2: further evidence that elephant shrew and aardvark join the paenungulate clade

A 328-bp sequence from exon 1 of the gene for aquaporin-2 (AQP2) was compared in 12 mammalian species, representing as many eutherian orders. This sequence encodes the N-terminal half of this kidney- specific water channel protein. Most amino acid replacements, as well as an insertion, have occurred in extracellular loops connecting the transmembrane helices, in agreement with a lower functional importance of these loops. Phylogenetic analyses were performed with parsimony, distance, and maximum-likelihood methods. The AQP2 data set, alone as well as in combination with previously published alpha A-crystallin protein sequences, strongly supports a clade consisting of elephant, hyrax, aardvark, and elephant shrew, reaching bootstrap values of 99%. This finding fully agrees with the only other presently available sequence data sets that include these taxa, those of von Willebrand factor and interphotoreceptor retinoid-binding protein, and suggests that this extended paenungulate clade is one of the most conspicuous superordinal groupings in eutherian phylogeny. Some support was obtained for an artiodactyl/perissodactyl clade, while the grouping of pholidotes with edentates was contradicted.      

AM representation in green treefrog auditory nerve fibers: neuroethological implications for pattern recognition and sound localization

In addition to spectral call components, temporal patterns in the advertisement-call envelope of green treefrog males (Hyla cinerea) provide important cues for female mate choice. Rapid amplitude modulation (AM) with rates of 250–300 Hz is typical for this species advertisement calls. Here we report data on the encoding of these rapid call modulations by studying the responses of single auditory nerve fibers to two-tone stimuli with envelope periodicities close to those of the natural call. The free-field response properties of 86 nerve fibers were studied from 32 anesthetized males. The accuracy of stimulus envelope coding was quantified using both a Gaussian function fit to the interspike interval histograms derived from the first seven 20-ms stimulus segments, and the vector-strength metric applied to the phase-locked responses. Often, AM encoding in the initial stimulus segment was more faithful than that in its second half. This result may explain why conspecific females prefer calls in which the initial segment is unmasked rather than masked. Both the questions of pattern recognition and localization are discussed, and the data are related to behavioral observations of female choice and localization performance in this species.     

Diet of bluegill Lepomis macrochirus in a South African reservoir during winter and summer

Alien fishes are considered a major threat to aquatic biodiversity in South Africa, yet relatively little regional information on their biology and ecology is available for many of these species. Seasonal changes in the diet of the bluegill Lepomis macrochirus in Howieson’s Poort Dam, Grahamstown, were assessed during summer and winter in 2014–2015, using stomach content analysis. In winter, juvenile and adult fish diets were dominated by crustacean zooplankton and insects, respectively. In summer, juvenile fish fed on crustaceans and insects, whereas adults consumed mostly fish eggs, indicating a potential impact by these invasive fish on native fish through oophagy.