The Efficacy of Ultrasound-guided Compression of Iatrogenic Femoral Pseudo-aneurysms

AbstractObjective to evaluate ultrasound guided compression (UGC) for the treatment of iatrogenic femoral pseudoaneurysms (PA). Design retrospective follow-up of 130 patients with suspected PA referred from the cardiac catheterisation laboratory over a 36-month period. Results the overall incidence of PA was 0.5% and was significantly higher after therapeutic (1.5%) than diagnostic (0.3%) procedures (p <0.000001). Forty-eight patients with a PA were treated with UGC with an 88% success rate. Success did not appear to be related to PA diameter.Conclusion the efficacy of UGC as treatment of PAs is confirmed

Mechanical limits of viral capsids

We study the elastic properties and mechanical stability of viral capsids under external force-loading with computer simulations. Our approach allows the implementation of specific geometries corresponding to specific phages such as $\phi$29 and CCMV. We demonstrate how in a combined numerical and experimental approach the elastic parameters can be determined with high precision. The experimentally observed bimodality of elastic spring constants is shown to be of geometrical origin, namely the presence of pentavalent units in the viral shell. A criterion for capsid breakage is defined, which explains well the experimentally observed rupture. From our numerics we find for the dependence of the rupture force on the F\"oppl-von K\'arm\'an (FvK) number a crossover from $\gamma^{2/3}$ to $\gamma^{1/2}$. For filled capsids high internal pressures lead to a stronger destabilization of viruses with a buckled ground state than unbuckled ones. Finally, we show how our numerically calculated energy maps can be used to extract information about the strength of protein-protein interactions from rupture experiments.Comment: 6 pages, 9 figure

Patient awareness and symptoms from an incisional hernia

Incisional hernia is a common postoperative complication following open abdominal surgery with incidence varying between 3% and 20%.1 Approximately half of all incisional hernias are diagnosed within 1 year following surgery. In the United Kingdom alone, about 10,000 incisional hernia repairs are performed annually. Incisional hernia repairs are generally elective with emergency repair due to incarceration or strangulation constituting about 15% of repairs.1 Incisional hernia repair is not a low-risk operation and generally has relatively poor results due to chronic postoperative pain and high recurrence rates.2−3 Little has been published on patients' awareness of incisional hernia following open abdominal surgery. Moreover, there are very few publications on indications for incisional hernia repair and on the natural course of such hernias. The literature suggests that symptoms and complaints usually presented by patients include pain, discomfort, cosmetic complaints, skin problems, incarceration, strangulation, functional disability, and pulmonary dysfunction.4−6 The aim of this study was to investigate whether patients were aware that they had a hernia. In addition, we sought to determine symptoms for those who knew that they had an incisional hernia

The refined structure of Nudaurelia capensis ω Virus reveals control elements for a T = 4 capsid maturation

AbstractLarge-scale reorganization of protein interactions characterizes many biological processes, yet few systems are accessible to biophysical studies that display this property. The capsid protein of Nudaurelia capensis ω Virus (NωV) has previously been characterized in two dramatically different T = 4 quasi-equivalent assembly states when expressed as virus-like particles (VLPs) in a baculovirus system. The procapsid (pH 7), is round, porous, and approximately 450 Å in diameter. It converts, in vitro, to the capsid form at pH 5 and the capsid is sealed shut, shaped like an icosahedron, has a maximum diameter of 410 Å and undergoes an autocatalytic cleavage at residue 570. Residues 571–644, the γ peptide, remain associated with the particle and are partially ordered. The interconversion of these states has been previously studied by solution X-ray scattering, electron cryo microscopy (CryoEM), and site-directed mutagenesis. The particle structures appear equivalent in authentic virions and the low pH form of the expressed and assembled protein. Previously, and before the discovery of the multiple morphological forms of the VLPs, we reported the X-ray structure of authentic NωV at 2.8 Å resolution. These coordinates defined the fold of the protein but were not refined at the time because of technical issues associated with the approximately 2.5 million reflection data set. We now report the refined, authentic virus structure that has added 29 residues to the original model and allows the description of the chemistry of molecular switching for T = 4 capsid formation and the multiple morphological forms. The amino and carboxy termini are internal, predominantly helical, and disordered to different degrees in the four structurally independent subunits; however, the refined structure shows significantly more ordered residues in this region, particularly at the amino end of the B subunit that is now seen to invade space occupied by the A subunits. These additional residues revealed a previously unnoticed strong interaction between the pentameric, γ peptide helices of the A and B subunits that are largely proximal to the quasi-6-fold axes. One C-terminal helix is ordered in the C and D subunits and stabilizes a flat interaction in two interfaces between the protein monomers while the other, quasi-equivalent, interactions are bent. As this helix is arginine rich, the comparable, disordered region in the A and B subunits probably interacts with RNA. One of the subunit–subunit interfaces has an unusual arrangement of carboxylate side chains. Based on this observation, we propose a mechanism for the control of the pH-dependent transitions of the virus particle

Ljudnivån i kycklingstallar

Ett arbete om olika ljudnivåer i kycklingstallar under en uppfödningsperiod. Hur ljudet förandras inne i stallet i tackt med att djur och ströbädd växer

Molecular structure refinement by direct fitting of atomic coordinates to experimental ESR spectra

An attempt is made to bypass spectral analysis and fit internal coordinates of radicals directly to experimental liquid- and solid-state electron spin resonance (ESR) spectra. We take advantage of the recently introduced large-scale spin dynamics simulation algorithms and of the fact that the accuracy of quantum mechanical calculations of ESR parameters has improved to the point of quantitative correctness. Partial solutions are offered to the local minimum problem in spectral fitting and to the problem of spin interaction parameters (hyperfine couplings, chemical shifts, etc.) being very sensitive to distortions in molecular geometry.Comment: Submitted for publicatio

The C-terminal fragment of the ribosomal P protein complexed to trichosanthin reveals the interaction between the ribosome-inactivating protein and the ribosome

Ribosome-inactivating proteins (RIPs) inhibit protein synthesis by enzymatically depurinating a specific adenine residue at the sarcin-ricin loop of the 28S rRNA, which thereby prevents the binding of elongation factors to the GTPase activation centre of the ribosome. Here, we present the 2.2 Å crystal structure of trichosanthin (TCS) complexed to the peptide SDDDMGFGLFD, which corresponds to the conserved C-terminal elongation factor binding domain of the ribosomal P protein. The N-terminal region of this peptide interacts with Lys173, Arg174 and Lys177 in TCS, while the C-terminal region is inserted into a hydrophobic pocket. The interaction with the P protein contributes to the ribosome-inactivating activity of TCS. This 11-mer C-terminal P peptide can be docked with selected important plant and bacterial RIPs, indicating that a similar interaction may also occur with other RIPs