Prospective randomized controlled trial: early weight bearing after conservative treatment of Weber B ankle fractures (pancake trial).

PURPOSE: Different studies have shown that weightbearing is safe in stable transsyndesmotic, isolated lateral simple ankle fractures. Despite this evidence, AO guidelines still recommend immobilization with above-the-knee cast for 4-6 weeks for these fractures. The objective of this study was to compare the outcomes of mobilization and weightbearing to those of immobilization and non-weightbearing in patients with stable transsyndesmotic, lateral isolated simple ankle fractures. METHODS: Fifty patients were randomly assigned to permissive weightbearing in a walking boot or non-weightbearing immobilization using a below-the-knee cast. Primary outcome was ankle functionality as scored by the Olerud-Molander Ankle Score (OMAS). Secondary outcomes were radiological displacement of fracture, range of motion (ROM), calf circumference, and RAND 36-item health survey. Patients were in follow-up for 24 months. RESULTS: Ankle functionality after six and twelve weeks was significantly higher for the intervention group, with respectively 30 points (p = 0.001) and 10 points (p = 0.015) of difference. ROM improved significantly in the intervention group after six weeks. All fractures showed radiological progression of fracture healing. RAND 36-item showed differences in both physical (60.3 vs. 46.3, p = 0.017) and mental (78.5 vs. 58.2, p = 0.034) components in favor of the intervention group. In 16% of patients who initially showed stable fractures on radiographic imaging, joint dislocation was identified on weightbearing radiographs prior to randomization, leading to exclusion. CONCLUSION: Weightbearing and mobilization using a walking boot may be a safe treatment for patients with stable Weber B fractures.

[A cachectic man with a severe vitamin deficiency]. / Een cachectische man met een ernstig vitaminetekort.

A 57-year-old man, known with severe malnutrition, vitamin E deficiency and peripheral neuropathies, presented with vomiting and abdominal tenderness. There was a suspicion of ileus and small bowel obstruction. During the exploratory laparotomy a complete brown colored bowel without peristalsis was seen.

[Breastfeeding in a multi-ethnic population: changes between 2009 and 2015]. / Borstvoeding in een multi-etnische populatie.

OBJECTIVE: To examine changes in breastfeeding rates in 0 to 6 month old infants in Amsterdam, the Netherlands, over the period from 2009 to 2015, for the total population as well as for various ethnic groups. DESIGN: Cross-sectional study. METHOD: Breastfeeding rates were examined for the period from 2009 to 2015 in 165,420 registrations of 75,543 infants at the ages of 2 weeks, 3 months and 6 months for the entire Amsterdam population and for various ethnic groups. Differences were analysed using χ2 tests. RESULTS: The weighted percentage of total breastfeeding (exclusive breastfeeding as well as a combination of breast and formula feeding) increased in the entire Amsterdam study population over the period from 2009 to 2015 (2 weeks: 87.8% to 89.1%; 3 months: 61.6% to 63.6%; 6 months: 39.5% to 42.2%). Increases were mainly the result of increases in weighted percentages for exclusive breastfeeding. The highest exclusive breastfeeding rates were observed among the Turkish ethnic group, the lowest among the Antillean/Aruban and Surinamese groups. CONCLUSION: Percentages for total breastfeeding as well as exclusive breastfeeding in Amsterdam rose over the period from 2009 to 2015, but there is room for improvement. Breastfeeding promotion, whether or not in combination with formula feeding, may be of particular benefit to children of Surinam or Antillean/Aruban descent. Before ethnicity-specific interventions can be implemented, more insight is needed in the reasons for the low breastfeeding rates in specific groups.

Uncovering the genetic signature of quantitative trait evolution with replicated time series data.

The genetic architecture of adaptation in natural populations has not yet been resolved: it is not clear to what extent the spread of beneficial mutations (selective sweeps) or the response of many quantitative trait loci drive adaptation to environmental changes. Although much attention has been given to the genomic footprint of selective sweeps, the importance of selection on quantitative traits is still not well studied, as the associated genomic signature is extremely difficult to detect. We propose 'Evolve and Resequence' as a promising tool, to study polygenic adaptation of quantitative traits in evolving populations. Simulating replicated time series data we show that adaptation to a new intermediate trait optimum has three characteristic phases that are reflected on the genomic level: (1) directional frequency changes towards the new trait optimum, (2) plateauing of allele frequencies when the new trait optimum has been reached and (3) subsequent divergence between replicated trajectories ultimately leading to the loss or fixation of alleles while the trait value does not change. We explore these 3 phase characteristics for relevant population genetic parameters to provide expectations for various experimental evolution designs. Remarkably, over a broad range of parameters the trajectories of selected alleles display a pattern across replicates, which differs both from neutrality and directional selection. We conclude that replicated time series data from experimental evolution studies provide a promising framework to study polygenic adaptation from whole-genome population genetics data.

Phylogeographic differentiation versus transcriptomic adaptation to warm temperatures in Zostera marina, a globally important seagrass.

Populations distributed across a broad thermal cline are instrumental in addressing adaptation to increasing temperatures under global warming. Using a space-for-time substitution design, we tested for parallel adaptation to warm temperatures along two independent thermal clines in Zostera marina, the most widely distributed seagrass in the temperate Northern Hemisphere. A North-South pair of populations was sampled along the European and North American coasts and exposed to a simulated heatwave in a common-garden mesocosm. Transcriptomic responses under control, heat stress and recovery were recorded in 99 RNAseq libraries with ~13 000 uniquely annotated, expressed genes. We corrected for phylogenetic differentiation among populations to discriminate neutral from adaptive differentiation. The two southern populations recovered faster from heat stress and showed parallel transcriptomic differentiation, as compared with northern populations. Among 2389 differentially expressed genes, 21 exceeded neutral expectations and were likely involved in parallel adaptation to warm temperatures. However, the strongest differentiation following phylogenetic correction was between the three Atlantic populations and the Mediterranean population with 128 of 4711 differentially expressed genes exceeding neutral expectations. Although adaptation to warm temperatures is expected to reduce sensitivity to heatwaves, the continued resistance of seagrass to further anthropogenic stresses may be impaired by heat-induced downregulation of genes related to photosynthesis, pathogen defence and stress tolerance.

Combining experimental evolution with next-generation sequencing: a powerful tool to study adaptation from standing genetic variation.

Evolve and resequence (E&R) is a new approach to investigate the genomic responses to selection during experimental evolution. By using whole genome sequencing of pools of individuals (Pool-Seq), this method can identify selected variants in controlled and replicable experimental settings. Reviewing the current state of the field, we show that E&R can be powerful enough to identify causative genes and possibly even single-nucleotide polymorphisms. We also discuss how the experimental design and the complexity of the trait could result in a large number of false positive candidates. We suggest experimental and analytical strategies to maximize the power of E&R to uncover the genotype-phenotype link and serve as an important research tool for a broad range of evolutionary questions.

Repeat chemonucleolysis is safe and effective.

A review was made of 85 patients who received a second injection of chymopapain because of a recurrent disc herniation between 1980 and 1996. All patients were pretreated for 3 days with H1 and H2 receptor blockers. Immediate sensitivity reactions were not seen. Four Type 1 and one Type 2 reactions were seen after the the second injection. No other complications were seen. In this group of 85 patients, 66 patients received a second injection at the same level as primary treatment after a period of 57.1 months (range, 2-143 months). Two patients were lost to followup. Four patients had surgery, three with good results. Good results and no complications were seen in three patients who had a third chemonucleolysis because of another recurrence after 15, 40, and 56 months, respectively. The remaining 57 patients were interviewed after 64 months (range, 3-143 months). Using the Prolo scale, 51 patients were rated as having excellent or good results, and six patients were rated as having fair or poor results.