Incidence and Risk Factors for Surgical Site Infection in Ankle Fractures: An Observational Study of 480 Patients in Sweden.

INTRODUCTION: Surgical site infection (SSI) is a frequently reported complication after ankle fracture surgery. To our knowledge, no study has been conducted on its incidence in Sweden. The present study aimed to determine the incidence of, risk factors for, and most common causative pathogen of SSI. METHODS: Patients who underwent primary surgery for an ankle fracture between 1 September 2017 and 31 August 2019 at the Sahlgrenska University Hospital were identified. Data on potential SSI risk factors and clinical outcome (infected/non-infected) were retrieved from medical records. Cox regression analysis and descriptive statistics were used. RESULTS: Of the 480 reviewed patients, 49 developed SSI (10.2%), of which 35 (7.3%) were superficial and 14 (2.9%) were deep. Open fractures (p < 0.001) and age (p = 0.016) were statistically significant risk factors for SSI in the univariate analysis. In the multivariable analysis, only open fracture was statistically significant (HR = 3.0; 95% C.I. = 1.3-6.9, p = 0.013). Cases of Staphylococcus aureus (S. aureus) were most common (n = 12, 24.5%). Methicillin resistance was uncommon (n = 2, 4.1%). CONCLUSIONS: An incidence of 10.2% was established, which is comparable to international findings. Infection monitoring is an important part of tackling the global challenge of antibiotic resistance. Future prospective studies to further establish risk factors are warranted to decrease the incidence of SSI.

Crystal polymorphism: dependence of oxygen diffusion through 2D ordered Co nanocrystals.

8 nm Co nanoparticles with various crystalline structures called polymorphs were produced using different synthetic procedures, such as using reverse micelles, the thermal decomposition of organometallics approach or the hot injection process. These 8 nm Co nanoparticles differing by their crystalline structures are exposed to oxygen at elevated temperature. The fcc Co polycrystalline nanoparticles produce either Co-CoO yolk-shell or CoO hollow structures whereas amorphous Co nanoparticles produce Co-CoO core-shell nanoparticles. Furthermore, single domains with either hcp or ε crystalline structure behave differently upon oxygen diffusion. Co-CoO nanoparticles were produced from the hcp phase while CoO hollow nanoparticles were the product for ε-phase Co nanocrystals.

A single-step competitive binding assay for mapping of single DNA molecules.

Optical mapping of genomic DNA is of relevance for a plethora of applications such as scaffolding for sequencing and detection of structural variations as well as identification of pathogens like bacteria and viruses. For future clinical applications it is desirable to have a fast and robust mapping method based on as few steps as possible. We here demonstrate a single-step method to obtain a DNA barcode that is directly visualized using nanofluidic devices and fluorescence microscopy. Using a mixture of YOYO-1, a bright DNA dye, and netropsin, a natural antibiotic with very high AT specificity, we obtain a DNA map with a fluorescence intensity profile along the DNA that reflects the underlying sequence. The netropsin binds to AT-tetrads and blocks these binding sites from YOYO-1 binding which results in lower fluorescence intensity from AT-rich regions of the DNA. We thus obtain a DNA barcode that is dark in AT-rich regions and bright in GC-rich regions with kilobasepair resolution. We demonstrate the versatility of the method by obtaining a barcode on DNA from the phage T4 that captures its circular permutation and agrees well with its known sequence.

A regulatory domain in the C-terminal extension of the yeast glycerol channel Fps1p.

The Saccharomyces cerevisiae gene FPS1 encodes an aquaglyceroporin of the major intrinsic protein (MIP) family. The main function of Fps1p seems to be the efflux of glycerol in the adaptation of the yeast cell to lower external osmolarity. Fps1p is an atypical member of the family, because the protein is much larger (669 amino acids) than most MIPs due to long hydrophilic extensions in both termini. We have shown previously that a short domain in the N-terminal extension of the protein is required for restricting glycerol transport through the channel (Tamás, M. J., Karlgren, S., Bill, R. M., Hedfalk, K., Allegri, L., Ferreira, M., Thevelein, J. M., Rydström, J., Mullins, J. G. L., and Hohmann, S. (2003) J. Biol. Chem. 278, 6337-6345). Deletion of the N-terminal domain results in an unregulated channel, loss of glycerol, and osmosensitivity. In this work we have investigated the role of the Fps1p C terminus (139 amino acids). A set of eight truncations has been constructed and tested in vivo in a yeast fps1Delta strain. We have performed growth tests, membrane localization following cell fractionation, and glycerol accumulation measurements as well as an investigation of the osmotic stress response. Our results show that the C-terminal extension is also involved in restricting transport through Fps1p. We have identified a sequence of 12 amino acids, residues 535-546, close to the sixth transmembrane domain. This element seems to be important for controlling Fps1p function. Similar to the N-terminal domain, the C-terminal domain is amphiphilic and has a potential to dip into the membrane.