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The soil bacterium Burkholderia pseudomallei causes melioidosis, a potentially fatal and greatly underdiagnosed tropical disease. Detection of B. pseudomallei in the environment is important to trace the source of infections, define risk areas for melioidosis and increase the clinical awareness. Although B. pseudomallei polymerase chain reaction (PCR)-based environmental detection provides important information, the culture of the pathogen remains essential but is still a methodological challenge. B. pseudomallei can catabolize erythritol, a metabolic pathway, which is otherwise rarely encountered among bacteria. We recently demonstrated that replacing threonine with erythritol as a single carbon source in the pH-neutral threonine-basal salt solution (TBSS-C50) historically used improved the isolation of B. pseudomallei from rice paddy soils. However, further culture medium parameters for an optimized recovery of B. pseudomallei strains from soils are still ill-defined. We, therefore, aimed to design a new erythritol-based medium by systematically optimizing parameters such as pH, buffer capacity, salt and nutrient composition. A key finding of our study is the enhanced erythritol-based growth of B. pseudomallei under acidic medium conditions. Our experiments with B. pseudomallei strains from different geographical origin led to the development of a phosphate-buffered acidic erythritol (ACER) medium with a pH of 6.3, higher erythritol concentration of 1.2%, supplemented vitamins and nitrate. This highly selective medium composition shortened the lag phase of B. pseudomallei cultures and greatly increased growth densities compared to TBSS-C50 and TBSS-C50-based erythritol medium. The ACER medium led to the highest enrichments of B. pseudomallei as determined from culture supernatants by quantitative PCR in a comparative validation with soil samples from the central part of Vietnam. Consequently, the median recovery of B. pseudomallei colony forming units on Ashdown's agar from ACER subcultures was 5.4 times higher compared to TBSS-C50-based erythritol medium (p = 0.005) and 30.7 times higher than TBSS-C50 (p < 0.001). In conclusion, our newly developed ACER medium significantly improves the isolation of viable B. pseudomallei from soils and, thereby, has the potential to reduce the rate of false-negative environmental cultures in melioidosis risk areas.

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Hydrophobic interaction membrane chromatography has gained interest due to its excellent performance in the purification of humanized monoclonal antibodies. The membrane material used in hydrophobic interaction membrane chromatography has typically been commercially available polyvinylidene fluoride. In this contribution, newly developed inverse colloidal crystal membranes that have uniform pores, high porosity and, therefore, high surface area for protein binding are used as hydrophobic interaction membrane chromatography membranes for humanized monoclonal antibody immunoglobulin G purification. The capacity of the inverse colloidal crystal membranes developed here is up to ten times greater than commercially available polyvinylidene fluoride membranes with a similar pore size. This work highlights the importance of developing uniform pore size high porosity membranes in order to maximize the capacity of hydrophobic interaction membrane chromatography.

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Double-stranded RNA (dsRNA) causes keratinocytes to release thymic stromal lymphopoietin (TSLP), which plays a key role in allergic diseases. Endosomal Toll-like receptor 3 (TLR3) and cytosolic RIG-like receptors (RLRs) and PKR have been reported to recognize dsRNA. Here, we demonstrate that dsRNA induces TSLP in keratinocytes via an endosomal acidification-dependent and NF-κB-mediated pathway. After treatment with pharmacologic inhibitors or transfection with small interfering RNAs (siRNAs), primary human keratinocytes were stimulated. Bafilomycin A1, which inhibits endosomal acidification to block the TLR3 pathway, blocked the dsRNA-induced expression of TSLP, IL-8, IFN-ß, and other molecules including the dsRNA sensors, whereas it did not inhibit diacyllipopeptide-induced expression of TSLP and IL-8. The dsRNA-induced gene expression of TSLP depended on RelA, a component of NF-κB, but not IRF3, similar to IL-8 but different from IFN-ß, which depended on both IRF3 and RelA. The results indicate that endosomal acidification and the subsequent activation of NF-κB are necessary to sense extracellular dsRNA, suggesting the importance of the TLR3-NF-κB axis to trigger production of TSLP against the self dsRNA released from damaged cells or viral dsRNA, in the epidermis, relating to skin inflammation including atopic dermatitis (AD).

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Starting from the data of Braune and Fischer on the human gait and of Fick on the hip muscles, the forces acting on the hip joint during gait are calculated in tridimensional space. The analysis confirms the study on the same subject by Pauwels with a simpler method, as far as the coronal projection is concerned. In the horizontal plane, the resultant force exerted on the hip seems to be greater and its direction is different from that described by Pauwels.

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