Reverse total shoulder arthroplasty for proximal humerus fractures: Primary or delayed after failed treatment?

Background: Reverse total shoulder arthroplasty (RTSA) has recently become an option for the treatment of proximal humerus fractures (PHFs) or as a salvage procedure after failure of another treatment. The purpose of this study was to compare primary RTSA with delayed RTSA in the treatment of displaced PHFs.

Study Design & Methods: A retrospective cohort study was conducted on patients with PHFs who were treated between May 2013 and December 2021 with primary or delayed RTSA after failure of conservative treatment or osteosynthesis.

, and Flocculation Gene Expression Impacts Attachment to in a Co-immobilization Technique.

A reoccurring flaw of most yeast immobilization systems that limits the potential of the technique is leakage of the cells from the matrix. Leakage may be due to weakly adherent cells, deterioration of the matrix, or to new growth and loss of non-adherent daughter cells. Yeast biocapsules are a spontaneous, cost effective system of immobilization whereby cells are attached to the hyphae of , creating hollow spheres that allow recovery and reutilization.

Structural basis for PHDVC5HCHNSD1-C2HRNizp1 interaction: implications for Sotos syndrome.

Sotos syndrome is an overgrowth syndrome caused by mutations within the functional domains ofNSD1 gene coding for NSD1, a multidomain protein regulating chromatin structure and gene expression. In particular, PHDVC5HCHNSD1 tandem domain, composed by a classical (PHDV) and an atypical (C5HCH) plant homeo-domain (PHD) finger, is target of several pathological missense-mutations. PHDVC5HCHNSD1 is also crucial for NSD1-dependent transcriptional regulation and interacts with the C2HR domain of transcriptional repressor Nizp1 (C2HRNizp1)in vitro To get molecular insights into the mechanisms dictating the patho-physiological relevance of the PHD finger tandem domain, we solved its solution structure and provided a structural rationale for the effects of seven Sotos syndrome point-mutations.

Comparing molecular dynamics force fields in the essential subspace.

The continued development and utility of molecular dynamics simulations requires improvements in both the physical models used (force fields) and in our ability to sample the Boltzmann distribution of these models. Recent developments in both areas have made available multi-microsecond simulations of two proteins, ubiquitin and Protein G, using a number of different force fields. Although these force fields mostly share a common mathematical form, they differ in their parameters and in the philosophy by which these were derived, and previous analyses showed varying levels of agreement with experimental NMR data.

Torsion and curvature of FtsZ filaments.

FtsZ filaments participate in bacterial cell division, but it is still not clear how their dynamic polymerization and shape exert force on the underlying membrane. We present a theoretical description of individual filaments that incorporates information from molecular dynamic simulations. The structure of the crystallized Methanococcus jannaschii FtsZ dimer was used to model a FtsZ pentamer that showed a curvature and a twist.

Simulation of catalytic water activation in mitochondrial F1-ATPase using a hybrid quantum mechanics/molecular mechanics approach: an alternative role for β-Glu 188.

The use of quantum mechanics/molecular mechanics simulations to study the free energy landscape of the water activation at the catalytic site of mitochondrial F(1)-ATPase affords us insight into the generation of the nucleophile OH(-) prior to ATP hydrolysis. As a result, the ATP molecule was found to be the final proton acceptor. In the simulated pathway, the transfer of a proton to the nucleotide was not direct but occurred via a second water molecule in a manner similar to the Grotthuss mechanism proposed for proton diffusion.

Molecular dynamics simulation of GTPase activity in polymers of the cell division protein FtsZ.

FtsZ, the prokaryotic ortholog of tubulin, assembles into polymers in the bacterial division ring. The interfaces between monomers contain a GTP molecule, but the relationship between polymerization and GTPase activity is not unequivocally proven. A set of short FtsZ polymers were modelled and the formation of active GTPase structures was monitored using molecular dynamics.

Molecular dynamics analysis of conformational change of paramyxovirus F protein during the initial steps of membrane fusion.

The fusion of paramyxovirus to the cell membrane is mediated by fusion protein (F protein) present in the virus envelope, which undergoes a dramatic conformational change during the process. Unlike hemagglutinin in orthomyxovirus, this change is not mediated by an alteration of environmental pH, and its cause remains unknown. Steered molecular dynamics analysis leads us to suggest that the conformational modification is mediated only by stretching mechanical forces once the transmembrane fusion peptide of the protein is anchored to the cell membrane.

The Role of Gln61 in HRas GTP hydrolysis: a quantum mechanics/molecular mechanics study.

Activation of the water molecule involved in GTP hydrolysis within the HRas·RasGAP system is analyzed using a tailored approach based on hybrid quantum mechanics/molecular mechanics (QM/MM) simulation. A new path emerges: transfer of a proton from the attacking water molecule to a second water molecule, then a different proton is transferred from this second water molecule to the GTP. Gln(61) will stabilize the transient OH(-) and H(3)O(+) molecules thus generated.