Factors associated with rifampin resistance in staphylococcal periprosthetic joint infections (PJI): a matched case-control study

Purpose: Rifampin combination therapy plays an important role in the management of staphylococcal periprosthetic joint infection (PJI). However, the emergence of rifampin resistance is a feared complication. We retrospectively analysed predetermined potential risk factors in patients with rifampin-resistant staphylococcal PJI in a multicentre case-control study. Methods: Cases (n=48) were defined as PJI caused by rifampin-resistant staphylococci. Rifampin-susceptible controls (n=48) were matched for microorganism and type of prosthetic joint. Uni- and multivariable conditional logistic regression analyses were performed to estimate odds ratios (OR) with 95% confidence intervals (95% CI). Results: Forty-eight cases (31 men; median age 67years; age range 39-88years) with hip- (n=29), knee- (n=13), elbow- (n=4), shoulder- (n=1) or ankle-PJI (n=1) were enrolled in the study. Staphylococcus aureus and coagulase-negative staphylococci were isolated in ten and 38 episodes, respectively. Most of the cases (n=44, 92%) had a previous PJI, and 93 % (n=41) of these had been treated with rifampin. There was an independent association of emergence of rifampin resistance with male sex (OR 3.6, 95% CI 1.2-11),≥3 previous surgical revisions (OR 4.7, 95% CI 1.6-14.2), PJI treatment with high initial bacterial load (inadequate surgical debridement, <2weeks of intravenous treatment of the combination medication; OR 4.9, 95% CI 1.6-15) and inadequate rifampin therapy (OR 5.4, 95% CI 1.2-25). Conclusions: Based on our results, extensive surgical debridement and adequate antibiotic therapy are needed to prevent the emergence of rifampin resistanc

Holomorphic automorphisms of Danielewski surfaces II -- structure of the overshear group

We apply Nevanlinna theory for algebraic varieties to Danielewski surfaces and investigate their group of holomorphic automorphisms. Our main result states that the overshear group which is known to be dense in the identity component of the holomorphic automorphism group, is a free amalgamated product.Comment: 24 page

Quiver Structure of Heterotic Moduli

We analyse the vector bundle moduli arising from generic heterotic compactifications from the point of view of quiver representations. Phenomena such as stability walls, crossing between chambers of supersymmetry, splitting of non-Abelian bundles and dynamic generation of D-terms are succinctly encoded into finite quivers. By studying the Poincar\'e polynomial of the quiver moduli space using the Reineke formula, we can learn about such useful concepts as Donaldson-Thomas invariants, instanton transitions and supersymmetry breaking.Comment: 38 pages, 5 figures, 1 tabl

4d N=2 Gauge Theories and Quivers: the Non-Simply Laced Case

We construct the BPS quivers with superpotential for the 4d N=2 gauge theories with non-simply laced Lie groups (B_n, C_n, F_4 and G_2). The construction is inspired by the BIKMSV geometric engineering of these gauge groups as non-split singular elliptic fibrations. From the categorical viewpoint of arXiv:1203.6743, the fibration of the light category L(g) over the (degenerate) Gaiotto curve has a monodromy given by the action of the outer automorphism of the corresponding unfolded Lie algebra. In view of the Katz--Vafa `matter from geometry' mechanism, the monodromic idea may be extended to the construction of (Q, W) for SYM coupled to higher matter representations. This is done through a construction we call specialization.Comment: 42 pages, 2 figure

Quadratic differentials as stability conditions

We prove that moduli spaces of meromorphic quadratic differentials with simple zeroes on compact Riemann surfaces can be identified with spaces of stability conditions on a class of CY3 triangulated categories defined using quivers with potential associated to triangulated surfaces. We relate the finite-length trajectories of such quadratic differentials to the stable objects of the corresponding stability condition.Comment: 123 pages; 38 figures. Version 2: hypotheses in the main results mildly weakened, to reflect improved results of Labardini-Fragoso and coauthors. Version 3: minor changes to incorporate referees' suggestions. This version to appear in Publ. Math. de l'IHE

Određivanje alergena Asp f 1 (Aspergillus fumigatus) u peradarniku enzimimunokemijskom metodom

Poultry farms contain high levels of allergenic fungi, and Aspergillus spp. is the most common genus of moulds. Aspergillus fumigatus antigens are responsible for the development of several respiratory diseases including asthma. The aim of this study was to measure the mass fraction of Asp f 1, a major allergen of Asperillus fumigatus in 37 indoor dust samples collected from four poultry farms in a rural area of the Zagreb County (Croatia) using the enzyme-linked immunosorbent assay. More than 62 % of dust samples had detectable Asp f 1 levels (limit of detection 3.6 ng g-1). The overall mean Asp f 1 level was 17.9 ng g-1 [range (3.8 to 72.4) ng g-1]. Satisfactory results were obtained for analytical within-run imprecision (6.7 %), between-run imprecision (10.5 %), and accuracy (91 % to 115 %). Microclimate parameters (air temperature, relative humidity, and velocity) were within the recommended ranges in all poultry farms. This study has shown that Asp f 1 settles on dust at poultry farms and that occupational exposure to this allergen deserves monitoring in livestock buildings.Peradarnici sadržavaju veliku koncentraciju alergenih plijesni, a rod Aspergillus najčešće je zastupljen. Antigeni soja Aspergillus fumigatus odgovorni su za nastanak nekoliko respiratornih bolesti uključujući astmu. Cilj ovoga rada bio je odrediti masenu frakciju Asp f 1, glavnog alergena soja Asperillus fumigatus u 37 uzoraka prašine uzorkovanih u četiri peradarnika sa šireg područja Zagrebačke županije rabeći enzimimunokemijsku metodu. Više od 62 % uzoraka prašine u tri peradarnika imalo je mjerljivu koncentraciju Asp f 1 (granica detekcije = 3.6 ng g-1). Ukupni srednji maseni udio Asp f 1 iznosio je 17.9 ng g-1 (raspon od 3.8 ng g-1 do 72.4 ng g-1). Dobiveni su zadovoljavajući rezultati za analitičku nepreciznost u seriji (6.7 %), nepreciznost iz dana u dan (10.5 %) i točnost (91 % do 115 %). Mikroklimatski parametri (temperatura zraka, relativna vlaga i protok zraka) u svim peradarnicima bili su u okviru preporučenih vrijednosti. Rezultati ovoga rada pokazuju da Asp f 1 sedimentira na prašinu u peradarnicima te da profesionalnu izloženost tom alergenu treba pratiti u jedinicama za uzgoj stoke

The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate! [Commentary]

The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis for chemical risk assessment in the EU. The plan is to bring chemical risk assessors and managers together with scientists to accelerate method development and the production of necessary data and knowledge, and to facilitate the transition to next-generation evidence-based risk assessment, a non-toxic environment and the European Green Deal. The NORMAN Network is an independent, well-established and competent network of more than 80 organisations in the field of emerging substances and has enormous potential to contribute to the implementation of the PARC partnership. NORMAN stands ready to provide expert advice to PARC, drawing on its long experience in the development, harmonisation and testing of advanced tools in relation to chemicals of emerging concern and in support of a European Early Warning System to unravel the risks of contaminants of emerging concern (CECs) and close the gap between research and innovation and regulatory processes. In this commentary we highlight the tools developed by NORMAN that we consider most relevant to supporting the PARC initiative: (i) joint data space and cutting-edge research tools for risk assessment of contaminants of emerging concern; (ii) collaborative European framework to improve data quality and comparability; (iii) advanced data analysis tools for a European early warning system and (iv) support to national and European chemical risk assessment thanks to harnessing, combining and sharing evidence and expertise on CECs. By combining the extensive knowledge and experience of the NORMAN network with the financial and policy-related strengths of the PARC initiative, a large step towards the goal of a non-toxic environment can be taken

Embryogenesis in Sedum acre L.: structural and immunocytochemical aspects of suspensor development

The changes in the formation of both the actin and the microtubular cytoskeleton during the differentiation of the embryo-suspensor in Sedum acre were studied in comparison with the development of the embryo-proper. The presence and distribution of the cytoskeletal elements were examined ultrastructurally and with the light microscope using immunolabelling and rhodamine-phalloidin staining. At the globular stage of embryo development extensive array of actin filaments is present in the cytoplasm of basal cell, the microfilament bundles generally run parallel to the long axis of basal cell and pass in close to the nucleus. Microtubules form irregular bundles in the cytoplasm of the basal cell. A strongly fluorescent densely packed microtubules are present in the cytoplasmic layer adjacent to the wall separating the basal cell from the first layer of the chalazal suspensor cells. At the heart-stage of embryo development, in the basal cell, extremely dense arrays of actin materials are located near the micropylar and chalazal end of the cell. At this stage of basal cell formation, numerous actin filaments congregate around the nucleus. In the fully differentiated basal cell and micropylar haustorium, the tubulin cytoskeleton forms a dense prominent network composed of numerous cross-linked filaments. In the distal region of the basal cell, a distinct microtubular cytoskeleton with numerous microtubules is observed in the cytoplasmic layer adjacent to the wall, separating the basal cell from the first layer of the chalazal suspensor cells. The role of cytoskeleton during the development of the suspensor in S. acre is discussed

Controversies in the antiphospholipid syndrome: can we ever stop warfarin?

Patients with antiphospholipid syndrome are at increased risk for recurrent arterial and venous thrombosis and therefore benefit from long term warfarin therapy. The optimal duration of warfarin therapy after a first venous thromboembolic event is however a matter of some controversy and many questions remain unanswered. After reviewing and analysing the available evidence, we discuss some common scenarios in everyday clinical practice where treatment decisions are difficult