Synovial fluid multiplex PCR is superior to culture for detection of low-virulent pathogens causing periprosthetic joint infection

Introduction

Analysis of joint aspirate is the standard preoperative investigation for diagnosis of periprosthetic joint infection (PJI). We compared the diagnostic performance of culture and multiplex polymerase chain reaction (PCR) of synovial fluid for diagnosis of PJI.

Involvement of histone H1 in the organization of the chromosome fiber.

At high ionic strength (e.g., physiological salt concentrations) chromosome fibers are 200 A in diameter and composed of discrete globular structures that are held together by histone H1. At low ionic strength the fibers unfold and appear as the familiar chains of nucleosomes (80 A in diameter). The unfolding of chromosome fibers occurs within a narrow salt range. It results from a change in the mode of the interaction between histone H1 and the chromosome fiber and is very likely the consequence of a change from cooperative binding between histone H1 and DNA to a noncooperative binding. In the noncooperative binding state histone H1 molecules are randomly redistributed along the chromosome fiber.     

Preferential and cooperative binding of histone I to chromosomal mammalian DNA.

There is a strong preferential binding of histone I to lymphocyte DNA as compared to Escherichia coli DNA when large DNA fragments (2 times 10-6 daltons) are used. The binding of histone I to lymphocyte DNA and to E. coli DNA is cooperative. The distribution of preferential binding sites has been investigated on fragmented DNA. Most of the 2 times 10-6 dalton fragments were found to have at least one preferential histone I binding site, whereas most of the 2 times 10-5 dalton fragments have none.     

Contribution of microRNA 24–3p and Erk1/2 to interleukin‐6‐mediated plasma cell survival

Plasma cells can survive for long periods and continuously secrete protective antibodies, but plasma cell production of autoantibodies or transformation to tumor cells is detrimental. Plasma cell survival depends on exogenous factors from the surrounding microenvironment, and largely unknown intracellular mediators that regulate cell homeostasis. Here we investigated the contribution of the microRNA 24–3p (miR‐24–3p) to the survival of human plasma cells under the influence of IL‐6 and SDF‐1α (stromal cell derived factor 1), both of which are bone marrow survival niche mediators. Deep sequencing revealed a strong expression of miR‐24–3p in primary B cells, plasma blasts, plasma cells, and in plasmacytoma cells. In vitro studies using primary cells and the plasmacytoma cell line RPMI‐8226 revealed that (i) expression of miR‐24–3p mediates plasma cell survival, (ii) miR‐24–3p is upregulated by IL‐6 and SDF‐1α, (iii) IL‐6 mediates cell survival under ER stress conditions via miR‐24–3p expression, and (iv) IL‐6‐induced miR‐24–3p expression depends on the activity of the MAP kinase Erk1/2. These results suggest a direct connection between an external survival signal and an intracellular microRNA in regulating plasma cell survival. miR‐24–3p could therefore be a promising target for new therapeutic strategies for autoimmune and allergic diseases and for multiple myeloma.     

Management periprothetischer Infektionen des Kniegelenks

Endoprosthetic replacement is one of the most successful operations in current medicine. As the implantation of knee prostheses increases, the number of periprosthetic infections is also rising. In case of painful or early loosening of the prosthesis an infection should be excluded by joint aspiration. Retention of the prosthesis with change of mobile parts is possible only in acute infections (<?4 weeks after surgery or duration of symptoms of <3 weeks in the case of hematogenous infection), if the prosthesis is stable, the soft tissue is intact, and no difficult-to-treat pathogens were found. In other cases a one- or two-stage prosthesis exchange should be performed. In a two-stage exchange, a short interval of 2–3 weeks is possible, if biofilm-active treatment is available. Rifampin should be used targeted (after isolation of the pathogen) and only in combination with another efficient antibiotic. In this article the current management concepts of periprosthetic infection of the knee are discussed.     

Lung CD11c+ cells from mice deficient in Epstein-Barr virus-induced gene 3 (EBI-3) prevent airway hyper-responsiveness in experimental asthma

Epstein-Barr virus-induced gene (EBI)-3 codes for a soluble type 1 cytokine receptor homologous to the p40 subunit of IL-12 that is expressed by antigen-presenting cells following activation. Here, we analyzed the functional role of EBI-3 in a murine model of asthma associated with airway hyper-responsiveness (AHR) in ovalbumin-sensitized mice. Upon allergen challenge, EBI-3-/- mice showed less severe AHR, decreased numbers and degranulation of eosinophils and a significantly reduced number of VCAM-1+ cells in the lungs as compared to wild-type littermates. We thus analyzed lung CD11c+ cells before and after allergen challenge in these mice and found that before allergen challenge, lung CD11c+ cells isolated from EBI-3-/- mice express markers of a more plasmacytoid phenotype without releasing IFN-alpha as compared to those from wild-type littermates. Moreover, allergen challenge induced the development of myeloid CD11c+ cells in the lungs of EBI-3-/- mice, which released increased amounts of IL-10 and IL-12 while not expressing IFN-alpha. Finally, inhibition of EBI-3 expression in lung DC could prevent AHR in adoptive transfer studies by suppressing mediator release of effector cells into the airways. These results indicate a novel role for EBI-3 in controlling local immune responses in the lungs in experimental asthma.     

Description of an advanced practice nursing consultative model to reduce restrictive siderail use in nursing homes

Researchers have demonstrated that the use of physical restraints in nursing homes can be reduced, particularly where advanced practice nurses (APNs) are utilized. We examined the link between APN practice, siderail reduction, and the costs of siderail alternatives in 273 residents in four Philadelphia nursing homes. The majority of participants were cognitively and physically impaired with multiple co-morbidities. APNs recommended a total of 1,275 siderail-alternative interventions aimed at reducing fall risk. The median cost of siderail alternatives to prevent falls per resident was $135. Residents with a fall history experienced a significantly higher cost of recommendation compared to non-fallers. Findings suggest that an APN consultation model can effectively be implemented through comprehensive, individualized assessment without incurring substantial costs to the nursing home.     

PVA gel as a potential adhesion barrier: a safety study in a large animal model of intestinal surgery

Background

Intra-abdominal adhesions following surgery are a major source of morbidity and mortality including abdominal pain and small bowel obstruction. This study evaluated the safety of PVA gel (polyvinyl alcohol and carboxymethylated cellulose gel) on intestinal anastomoses and its potential effectiveness in preventing adhesions in a clinically relevant large animal model.

Methods

Experiments were performed in a pig model with median laparotomy and intestinal anastomosis following small bowel resection. The primary endpoint was the safety of PVA on small intestinal anastomoses. We also measured the incidence of postoperative adhesions in PVA vs. control groups: group A (eight pigs): stapled anastomosis with PVA gel compared to group B (eight pigs), which had no PVA gel; group C (eight pigs): hand-sewn anastomosis with PVA gel compared to group B (eight pigs), which had no anti-adhesive barrier. Animals were sacrificed 14 days after surgery and analyzed.

Results

All anastomoses had a patent lumen without any stenosis. No anastomoses leaked at an intraluminal pressure of 40 cmH₂O. Thus, anastomoses healed very well in both groups, regardless of whether PVA was administered. PVA-treated animals, however, had significantly fewer adhesions in the area of stapled anastomoses. The hand-sewn PVA group also had weaker adhesions and trended towards fewer adhesions to adjacent organs.

Conclusion

These results suggest that PVA gel does not jeopardize the integrity of intestinal anastomoses. However, larger trials are needed to investigate the potential of PVA gel to prevent adhesions in gastrointestinal surgery.     

Shrunken pore syndrome,preeclampsia, and markers of NO metabolism in pregnant women during the first trimester

Shrunken pore syndrome (SPS) is a condition that manifests itself as the decreased renal clearance of low-molecular-weight proteins but normal clearance of creatinine. Pregnant women with evidence of SPS during the first trimester have an increased risk of developing preeclampsia (PE). The nitric oxide (NO) metabolism markers arginine and ADMA, especially their ratio (Arg/ADMA), are recognized markers of endothelial dysfunction. The aim of this nested case–control study was to establish first-trimester reference intervals (RI) for markers of NO metabolism and to study these markers in women with evidence of SPS at the end of the first trimester. Seventy-four women were stratified in the first trimester according to evidence of SPS (SPS?+?or SPS–) and the occurrence of PE during subsequent pregnancy (PE?+?or PE–), as follows: SPS–/PE–, SPS+/PE–, SPS–/PE+, and SPS+/PE+. RIs were determined according to the CLSI EP28-A3c guidelines. Serum Arg and ADMA levels were analyzed. The Arg and ADMA concentrations did not differ among the four groups. However, women in the SPS+/PE?+?group had a significantly lower Arg/ADMA ratio than those in the other 3 groups (p?=?.02). In conclusion, we defined the first-trimester RI of Arg, ADMA and the Arg/ADMA ratio as markers of NO metabolism. Our results suggest that SPS in the first trimester predicts a pathophysiological hallmark of subsequent PE, i.e. lower NO production leading to increased vessel tone. Early identification of women at risk for later PE could lead to adaptive prophylactic interventions, such as supplementation with Arg or an NO-donor drug in order to mitigate the risk of developing PE.     

EAACI position paper on diet diversity in pregnancy,infancy and childhood: Novel concepts and implications for studies in allergy and asthma

To fully understand the role of diet diversity on allergy outcomes and to set standards for conducting research in this field, the European Academy of Allergy and Clinical Immunology Task Force on Diet and Immunomodulation has systematically explored the association between diet diversity and allergy outcomes. In addition, a detailed narrative review of information on diet quality and diet patterns as they pertain to allergic outcomes is presented. Overall, we recommend that infants of any risk category for allergic disease should have a diverse diet, given no evidence of harm and some potential association of benefit in the prevention of particular allergic outcomes. In order to harmonize methods for future data collection and reporting, the task force members propose relevant definitions and important factors for consideration, when measuring diet diversity in the context of allergy. Consensus was achieved on practice points through the Delphi method. It is hoped that the definitions and considerations described herein will also enable better comparison of future studies and improve mechanistic studies and pathway analysis to understand how diet diversity modulates allergic outcomes.