Latitudinal variation in soil nematode communities under climate warming-related range-expanding and native plants.

Current climate change has led to latitudinal and altitudinal range expansions of numerous species. During such range expansions, plant species are expected to experience changes in interactions with other organisms, especially with belowground biota that have a limited dispersal capacity. Nematodes form a key component of the belowground food web as they include bacterivores, fungivores, omnivores and root herbivores. However, their community composition under climate change-driven intracontinental range-expanding plants has been studied almost exclusively under controlled conditions, whereas little is known about actual patterns in the field. Here, we use novel molecular sequencing techniques combined with morphological quantification in order to examine nematode communities in the rhizospheres of four range-expanding and four congeneric native species along a 2,000 km latitudinal transect from South-Eastern to North-Western Europe. We tested the hypotheses that latitudinal shifts in nematode community composition are stronger in range-expanding plant species than in congeneric natives and that in their new range, range-expanding plant species accumulate fewest root-feeding nematodes. Our results show latitudinal variation in nematode community composition of both range expanders and native plant species, while operational taxonomic unit richness remained the same across ranges. Therefore, range-expanding plant species face different nematode communities at higher latitudes, but this is also the case for widespread native plant species. Only one of the four range-expanding plant species showed a stronger shift in nematode community composition than its congeneric native and accumulated fewer root-feeding nematodes in its new range. We conclude that variation in nematode community composition with increasing latitude occurs for both range-expanding and native plant species and that some range-expanding plant species may become released from root-feeding nematodes in the new range.

Differential responses of soil bacteria, fungi, archaea and protists to plant species richness and plant functional group identity.

Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities in the bulk soil are still not well understood. Here, we used 454-pyrosequencing to analyse the soil microbial community composition in a long-term biodiversity experiment at Jena, Germany. We examined responses of bacteria, fungi, archaea, and protists to plant species richness (communities varying from 1 to 60 sown species) and plant FG identity (grasses, legumes, small herbs, tall herbs) in bulk soil. We hypothesized that plant species richness and FG identity would alter microbial community composition and have a positive impact on microbial species richness. Plant species richness had a marginal positive effect on the richness of fungi, but we observed no such effect on bacteria, archaea and protists. Plant species richness also did not have a large impact on microbial community composition. Rather, abiotic soil properties partially explained the community composition of bacteria, fungi, arbuscular mycorrhizal fungi (AMF), archaea and protists. Plant FG richness did not impact microbial community composition; however, plant FG identity was more effective. Bacterial richness was highest in legume plots and lowest in small herb plots, and AMF and archaeal community composition in legume plant communities was distinct from that in communities composed of other plant FGs. We conclude that soil microbial community composition in bulk soil is influenced more by changes in plant FG composition and abiotic soil properties, than by changes in plant species richness per se.

Ultrasonographic analysis in knee osteoarthritis: evaluation of inter-observer reliability.

OBJECTIVES: Evidence for the validity of US in detecting structural joint pathology in OA is increasing. However, despite the rapidly emerging field of US in OA, few studies have reported on the inter-observer reliability of US to date. The objective of this study was to assess inter-observer reliability of ultrasonography (US) in the evaluation of specifically defined features in osteoarthritis (OA) of the knee. METHODS: US was performed independently by two rheumatologists in 60 outpatients fulfilling the American College of Rheumatology clinical criteria for knee OA. The acquisition protocol comprised medial meniscus protrusion, synovial hypertrophy, effusion, infrapatellar bursitis and cartilage thickness. Cartilage thickness and meniscal protrusion (if >3 mm) were measured on a continuous scale, all other variables were scored dichotomously. RESULTS: Inter-observer agreement (κ-value) was moderate for protrusion of the medial meniscus (0.54), good for infrapatellar bursitis (0.66) and effusion (0.74), excellent for Bakers' cyst (0.85) and poor for the detection of synovial hypertrophy (-0.08). Inter-observer reliability was good for the measurement of medial meniscus protrusion (correlation coefficient 0.80, 95% limits of agreement -1.93 to 1.94 mm) and cartilage thickness (correlation coefficient 0.62 and 0.68, 95% limits of agreement -0.87 to 0.84 mm and -0.77 to 0.96 mm at the medial and lateral condyle respectively). CONCLUSIONS: This study demonstrated good reproducibility of US in the assessment of the majority of the investigated mechanical, inflammatory and degenerative features of knee OA, and contributes to exploring the use of US in knee OA as a useful tool in research as well as in clinical practice.

Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain kappa and lambda to polyclonal antibody-based assays and immunofixation electrophoresis.

BACKGROUND: New monoclonal antibody-based assays for serum-free light chains (FLC) have become available. METHODS: In a clinical study with 541 patients, the new N Latex FLC assays were compared with the Freelite FLC assays and immunofixation electrophoresis (IF). RESULTS: Comparison of the different FLC kappa (κ) assays showed a slope of 0.99 with a deviation of 5.0%, rs=0.92, for FLC lambda (λ) a slope of 1.22, deviation 13.8%, rs=0.90 and for the κ/λ ratio a slope of 0.72, deviation -4.6%, rs=0.72. The concordance for the FLC κ assays was 91%, for FLC λ 85% and κ/λ ratio 95%. The clinical sensitivity and specificity of the κ/λ ratios in the study were comparable: 60% and 99% for the N Latex FLC assay and 61% and 97% for the Freelite assay. In IF-FLC positive samples, the N Latex FLC κ/λ ratio scored 20/23 (87%) samples outside the reference range and Freelite 21/23 (91%). For IF-FLC negative samples, N Latex FLC assay κ/λ ratio scored 338/350 (97%) within the reference range and Freelite scored 332/350 (95%). CONCLUSIONS: The concordance scores and the clinical sensitivity and specificity of the new N Latex FLC assays and Freelite assays appeared comparable, but there are some differences in measurement of concentrations between the methods.

[Various manifestations of calcium pyrophosphate-associated arthritis]. / De diverse uitingen van calciumpyrofosfaat-artritis.

In calcium pyrophosphate (CPP)-associated arthritis, deposits of calcium pyrophosphate lead to acute attacks of painful joint inflammation. The disease may present with signs of systemic inflammation such as fever, mimicking an infectious disease. Early recognition and treatment of this disease can prevent overdiagnosis and joint damage. In this article we describe three different patient cases of CPP-associated arthritis. The diversity of clinical presentation in CPP-associated arthritis can be of interest to different medical specialties who will occasionally encounter them in daily practice.

Root traits and belowground herbivores relate to plant-soil feedback variation among congeners.

Plant-soil feedbacks contribute to vegetation dynamics by species-specific interactions between plants and soil biota. Variation in plant-soil feedbacks can be predicted by root traits, successional position, and plant nativeness. However, it is unknown whether closely related plant species develop more similar plant-soil feedbacks than more distantly related species. Where previous comparisons included plant species from distant phylogenetic positions, we studied plant-soil feedbacks of congeneric species. Using eight intra-continentally range-expanding and native Geranium species, we tested relations between phylogenetic distances, chemical and structural root traits, root microbiomes, and plant-soil feedbacks. We show that root chemistry and specific root length better predict bacterial and fungal community composition than phylogenetic distance. Negative plant-soil feedback strength correlates with root-feeding nematode numbers, whereas microbiome dissimilarity, nativeness, or phylogeny does not predict plant-soil feedbacks. We conclude that root microbiome variation among congeners is best explained by root traits, and that root-feeding nematode abundances predict plant-soil feedbacks.

Soil functional responses to drought under range-expanding and native plant communities.

Current climate warming enables plant species and soil organisms to expand their range to higher latitudes and altitudes. At the same time, climate change increases the incidence of extreme weather events such as drought. While it is expected that plants and soil organisms originating from the south are better able to cope with drought, little is known about the consequences of their range shifts on soil functioning under drought events.Here, we test how range-expanding plant species and soil communities may influence soil functioning under drought. We performed a full-factorial outdoor mesocosm experiment with plant communities of range expanders or related natives, with soil inocula from the novel or the original range, with or without summer drought. We measured litter decomposition, carbon mineralization and enzyme activities, substrate-induced respiration and the relative abundance of soil saprophytic fungi immediately after drought and at 6 and 12 weeks after rewetting.Drought decreased all soil functions regardless of plant and soil origin except one; soil respiration was less reduced in soils of range-expanding plant communities, suggesting stronger resistance to drought. After rewetting, soil functioning responses depended on plant and soil origin. Soils of native plant communities with a history of drought had more litter mass loss and higher relative abundance of saprophytic fungi than soils without drought and soils of range expanders. Functions of soil from range expanders recovered in a more conservative manner than soils of natives, as litter mass loss did not exceed the control rates. At the end of the experiment, after rewetting, most soil functions in mesocosms with drought history did not differ anymore from the control.We conclude that functional consequences of range-expanding plants and soil biota may interact with effects of drought and that these effects are most prominent during the first weeks after rewetting of the soil. A free http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13453/suppinfo can be found within the Supporting Information of this article.

[A man with rheumatoid arthritis and a painful neck]. / Hevige nekpijn bij een man met reumatoïde artritis.

An 80-year-old man with long-standing rheumatoid arthritis presented with severe neck pain. No preceding trauma had occurred and he had no neurological complaints. A CT scan revealed vertical atlanto-axial subluxation without compression of the medulla oblongata. After conservative treatment the pain diminished. There were no neurological complications at follow-up.

Prognostic value of renal hemodynamic characteristics in patients with proliferative lupus nephritis.

BACKGROUND/AIM: Previous studies showed that renal hemodynamic parameters, especially the filtration fraction (FF), are decreased in patients with active lupus nephritis (LN). In this study, we evaluate the prognostic value of renal hemodynamic function tests on the renal outcome in patients with proliferative LN. METHODS: We performed a retrospective cohort study of our patients with proliferative LN from 1986 to 2005. Glomerular filtration rate (GFR) and FF before treatment were measured. Treatment failure was defined as a renal relapse or development of end-stage renal disease. RESULTS: Thirty-seven patients were included. The median follow-up period was 8 years. Creatinine clearance, GFR, and FF before treatment correlated with the creatinine clearance at the end of follow-up (p = 0.001, p = 0.006, and p = 0.04, respectively). The FF was decreased in 92% of our patients, but FF and GFR did not have a prognostic value with regard to treatment failure. CONCLUSIONS: Most patients with proliferative LN had a low FF. Low GFR and FF at baseline were correlated with a worse renal function at the end of follow-up, but this had no prognostic value in individual patients.

[Unexplained pain in the ankle and foot. Consider transient osteoporosis]. / Onbegrepen pijn van de enkel en voet. Denk aan voorbijgaande osteoporose.

Transient osteoporosis is an increasingly recognized condition that causes severe pain in weight-bearing joints and is characterized by otherwise unexplained bone-marrow oedema on MRI. We present two patients, a 40-year-old man and a 60-year-old woman, with longstanding severe pain in the foot and ankle. Both had invalidating pain with only mild swelling of the foot or ankle. Laboratory investigation was unremarkable, and conventional X-ray showed osteopenia of the bones involved. In both cases, consecutive MRIs showed migrating bone marrow oedema. The patients were treated with analgesics, immobilization of the body parts concerned and an intravenous bisphosphonate.

[A man with swollen fingers]. / Een man met zwellingen van de vingers.

A 28-year-old man was referred to our hospital because of localised swelling of his fingers, with suspicion of arthritis of the proximal interphalangeal (PIP) joints. At physical examination we observed a swelling, superficial to the PIP joints. Ultrasonography revealed a hypo-echoic structure above the extensor tendon, typical for knuckle pads.

Lack of association of C-C chemokine receptor 5 Δ32 deletion status with rheumatoid arthritis, systemic lupus erythematosus, lupus nephritis, and disease severity.

OBJECTIVE: C-C chemokine receptor 5 (CCR5) plays an important role in inflammation. A 32 base-pair (Δ32) deletion in the CCR5 gene leads to a nonfunctional receptor. This deletion has been reported to have a protective effect on the development and progression of several autoimmune diseases. We investigated whether the Δ32 deletion is associated with disease susceptibility in a population of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and lupus nephritis (LN); and whether it is associated with disease severity. METHODS: DNA samples from 405 RA patients, 97 SLE patients, 113 LN patients, and 431 healthy controls were genotyped for the CCR5 Δ32 deletion. Differences in genotype frequencies were tested between patients and controls. Association of genotypes with disease severity was analyzed. RESULTS: Genotype frequencies of each group were in Hardy-Weinberg equilibrium. The genotype frequencies of patients did not differ significantly from controls (CCR5/Δ32, Δ32/Δ32: RA 18.3% and 1.2%, respectively; SLE 17.5% and 2.1%; LN 13.3% and 1.8%; controls 20.0% and 2.8%). However, there was a trend for lower Δ32 deletion allele frequency in LN patients compared to controls (p = 0.08). There was no significant association between the CCR5 status and disease severity in RA, SLE, or LN. CONCLUSION: Although an association with LN cannot be excluded, the CCR5 Δ32 deletion does not seem to be a disease susceptibility genotype for RA, SLE, or LN. No significant effect of the Δ32 deletion on disease severity was demonstrated.

[Serious sequelae of hypothermia in cryoglobulinaemia]. / Ernstige gevolgen van afkoeling bij cryoglobulinemie.

Cryoglobulinaemia was diagnosed in three patients. The first was a 61-year-old man with severe skin involvement and polyneuropathy caused by type I cryoglobulinaemia associated with a small B cell clone in the bone marrow. A 73-year-old woman presented with neuropathy and renal and skin involvement due to type II cryoglobulinaemia associated with hepatitis C virus infection. The third patient was a 23-year-old woman with skin and renal involvement caused by type III cryoglobulinaemia. Cryoglobulins are circulating proteins that precipitate below a temperature of 37 degrees Celsius. This precipitation causes several signs and symptoms and, in some cases, severe organ damage. According to the Brouet classification, there are three different types of cryoglobulinaemia. Treatment focuses on their underlying causes and on the prevention of cryoglobulin precipitation. It is important to avoid hypothermia, which was the cause of severe manifestations in two of our patients.

A newly identified deletion of 970 bp at the alpha-globin locus that removes the promoter region of the alpha1 gene.

The most common causes of alpha-thalassemia (thal) are deletions that remove a part, or one or both of the functional alpha-globin genes. These deletions cause diminished expression of the alpha-globin protein, which may result in relatively low hemoglobin (Hb) and/or mean corpuscular volume (MCV) values. We here report the identification of a 970 bp deletion in the alpha1-globin gene that encompasses the entire promoter region of the alpha1-globin gene and 26 bp encoding the 5' end of the mRNA. Thus, the affected alpha1-globin gene is prone to be nonfunctional. We therefore nominated the newly identified deletion allele alpha-alphaDelta970. The MCV values of four related carriers of the alpha-alphaDelta970 allele were slightly lowered, consistent with the presence of three functional alpha-globin genes.