Caveolae disassemble upon membrane lesioning and foster cell survival.

Repair of lesions in the plasma membrane is key to sustaining cellular homeostasis. Cells maintain cytoplasmic as well as membrane-bound stores of repair proteins that can rapidly precipitate at the site of membrane lesions. However, little is known about the origins of lipids and proteins for resealing and repair of the plasma membrane.

Increased dislocation rates following total hip arthroplasty in patients with ankylosing spondylitis.

Background: Patients with ankylosing spondylitis (AS) experience abnormal spinopelvic motion due to chronic inflammation of the axial skeleton, predisposing them to impingement and dislocation. The purpose of this study was to evaluate total hip arthroplasty (THA) dislocation rates in AS patients and evaluate the effects of age and gender on dislocation risk.

Methods: Patients who underwent primary THA from 2005 to 2014 were identified using the PearlDiver database.

Single molecule localization-based analysis of clathrin-coated pit and caveolar dynamics.

Clathrin-coated pits and caveolae are nanoscale invaginations of the plasma membrane of cells, forming through the assembly of membrane coat and accessory proteins in a tightly regulated process. We have analyzed the development of these membrane coat structures with high spatial and temporal resolution and sensitivity using super-resolution single-molecule localization microscopy (SMLM) on live cells. To this end, we developed a sophisticated clustering and data analysis workflow that automatically extracts the relevant information from SMLM image sequences taken on live cells.

Expression and Localization of AβPP in SH-SY5Y Cells Depends on Differentiation State.

Neuroblastoma cell line SH-SY5Y, due to its capacity to differentiate into neurons, easy handling, and low cost, is a common experimental model to study molecular events leading to Alzheimer's disease (AD). However, it is prevalently used in its undifferentiated state, which does not resemble neurons affected by the disease. Here, we show that the expression and localization of amyloid-β protein precursor (AβPP), one of the key molecules involved in AD pathogenesis, is dramatically altered in SH-SY5Y cells fully differentiated by combined treatment with retinoic acid and BDNF.

Single-Color Fluorescence Lifetime Cross-Correlation Spectroscopy In Vivo.

The ability to quantify protein concentrations and to measure protein interactions in vivo is key information needed for the understanding of complex processes inside cells, but the acquisition of such information from living cells is still demanding. Fluorescence-based methods like two-color fluorescence cross-correlation spectroscopy can provide this information, but measurement precision is hampered by various sources of errors caused by instrumental or optical limitations such as imperfect overlap of detection volumes or detector cross talk. Furthermore, the nature and properties of used fluorescent proteins or fluorescent dyes, such as labeling efficiency, fluorescent protein maturation, photostability, bleaching, and fluorescence brightness can have an impact.

Mixed polar-nonpolar lipid films as minimalistic models of Tear Film Lipid Layer: A Langmuir trough and fluorescence microscopy study.

The Tear Film Lipid Layer (TFLL) covering the surface of the aqueous film at human cornea forms a first barrier between the eye and environment. Its alterations are related to dry eye disease. TFLL is formed by a complex mixture of lipids, with an excess of nonpolar components and a minor fraction of polar molecules.

A Cam-Post Mechanism Is No Longer Necessary in Modern Primary Total Knee Arthroplasty.

Conclusive evidence supporting a clinical difference between posterior-stabilized (PS) and cruciate-retaining (CR) designs in total knee arthroplasty (TKA) does not currently exist, despite both designs being used for decades. Proponents of PS designs that employ a cam-and-post mechanism cite in vivo fluoroscopic data that demonstrate improved posterior rollback; however, optimal rollback has never been correlated to superior clinical outcomes. Recently, anterior-lipped and more conforming CR bearings, such as ultracongruent, medial pivot, and dual-pivot designs, have been used to substitute for the posterior cruciate ligament and obviate the need for the cam-post mechanism of a traditional PS design.

Early Results From the American Joint Replacement Registry: A Comparison With Other National Registries.

Background: The American Joint Replacement Registry (AJRR) was created to capture knee and hip arthroplasty data in the United States. The purpose of this study was to compare early reports from the AJRR to other national registries to identify topics for future analysis.

Methods: Hip and knee arthroplasty data were extracted from the AJRR, Australia, New Zealand, United Kingdom, Norway, and Sweden from 2014 to 2016.

Late Dislocation Following Total Hip Arthroplasty: Spinopelvic Imbalance as a Causative Factor.

Background: Late dislocations after total hip arthroplasty (THA) are challenging for the hip surgeon because the cause is often not evident and recurrence is common. Recently, decreased spinopelvic motion has been implicated as a cause of dislocation. The purpose of this study was to assess the mechanical causes of late dislocation, including the influence of spinopelvic motion.

Genome-wide C-SWAT library for high-throughput yeast genome tagging.

Here we describe a C-SWAT library for high-throughput tagging of Saccharomyces cerevisiae open reading frames (ORFs). In 5,661 strains, we inserted an acceptor module after each ORF that can be efficiently replaced with tags or regulatory elements. We validated the library with targeted sequencing and tagged the proteome with bright fluorescent proteins to quantify the effect of heterologous transcription terminators on protein expression and to localize previously undetected proteins.

Total Hip Arthroplasty Bearing Surface Trends in the United States From 2007 to 2014: The Rise of Ceramic on Polyethylene.

Background: Wear of the bearing surface is a critical element in determining the longevity of a total hip arthroplasty (THA). Over the past decade, concerns related to modern metal-on-metal (MoM) bearings and corrosion at the femoral head-neck interface have influenced surgeon selection of bearing surfaces. The purpose of this study is to analyze trends in THA bearing surface selection from 2007 through 2014 using a large national database.

Cells Escape an Operational Mitotic Checkpoint through a Stochastic Process.

Improperly attached chromosomes activate the mitotic checkpoint that arrests cell division before anaphase. Cells can maintain an arrest for several hours but eventually will resume proliferation, a process we refer to as adaptation. Whether adapting cells bypass an active block or whether the block has to be removed to resume proliferation is not clear.

Spinopelvic mobility and acetabular component position for total hip arthroplasty.

Aims: Posterior tilt of the pelvis with sitting provides biological acetabular opening. Our goal was to study the post-operative interaction of skeletal mobility and sagittal acetabular component position.

Materials And Methods: This was a radiographic study of 160 hips (151 patients) who prospectively had lateral spinopelvic hip radiographs for skeletal and implant measurements.

Comprehensive study on critical micellar concentrations of SDS in acetonitrile-water solvents.

The CMC is one of the fundamental characteristics of surfactants and its determination is crucial for detail understanding of micelles formation. In this study the CMC of SDS in presence of ACN was determined by two independent experimental techniques, capillary electrophoresis and fluorescence correlation spectroscopy (FCS). Yet, studies of SDS micellization in solutions containing ACN as organic modifier are sparse and inconsistent in literature.

PCR Duplication: A One-Step Cloning-Free Method to Generate Duplicated Chromosomal Loci and Interference-Free Expression Reporters in Yeast.

Here, we report on a novel PCR targeting-based strategy called 'PCR duplication' that enables targeted duplications of genomic regions in the yeast genome using a simple PCR-based approach. To demonstrate its application we first duplicated the promoter of the FAR1 gene in yeast and simultaneously inserted a GFP downstream of it. This created a reporter for promoter activity while leaving the FAR1 gene fully intact.

Phospholipid lateral diffusion in phosphatidylcholine-sphingomyelin-cholesterol monolayers; effects of oxidatively truncated phosphatidylcholines.

Oxidative stress is involved in a number of pathological conditions and the generated oxidatively modified lipids influence membrane properties and functions, including lipid-protein interactions and cellular signaling. Brewster angle microscopy demonstrated oxidatively truncated phosphatidylcholines to promote phase separation in monolayers of 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (POPC), sphingomyelin (SM) and cholesterol (Chol). More specifically, 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), was found to increase the miscibility transition pressure of the SM/Chol-phase.

Systematic review of literature of cemented femoral components: what is the durability at minimum 20 years followup?

Background: Cemented femoral total hip arthroplasty may be one of the most successful surgical interventions of all time. However, although results are very encouraging over the early to mid-term followup, relatively few studies have analyzed the durability of these implants beyond 20 years followup. To evaluate the performance of contemporary implants, it is important to understand how previous implants perform at 20 or more years of followup; one way to do this is to aggregate the available data in the form of a systematic review.

Fixation and wear with a contemporary acetabular component and cross-linked polyethylene at minimum 10-year follow-up.

Unlabelled: Long term total hip arthroplasty follow-up has demonstrated bearing surface wear and failure of fixation as the major modes of failure. The purpose of this study was to evaluate the minimum 10year results of a third generation cementless acetabular component using moderately cross-linked polyethylene liners. 150 primary THAs were evaluated clinically for need for revision and activity evaluated using accelerometers, WOMAC, Tegner and UCLA activity-level scores.

Comprehensive portrait of cholesterol containing oxidized membrane.

Biological membranes are under significant oxidative stress caused by reactive oxygen species mostly originating during cellular respiration. Double bonds of the unsaturated lipids are most prone to oxidation, which might lead to shortening of the oxidized chain and inserting of terminal either aldehyde or carboxylic group. Structural rearrangement of oxidized lipids, addressed already, is mainly associated with looping back of the hydrophilic terminal group.

The fast polarization modulation based dual-focus fluorescence correlation spectroscopy.

We introduce two new alternative experimental realizations of dual focus fluorescence correlation spectroscopy (2fFCS), a method which allows for obtaining absolute diffusion coefficient of fast moving fluorescing molecules at nanomolar concentrations, based on fast polarization modulation of the excitation beam by a resonant electro-optical modulator. The first approach rotates every second linearly polarized laser pulse by 90 degrees to obtain independent intensity readout for both foci, similar to original design. The second approach combines polarization modulation of cw laser and fluorescence lifetime correlation spectroscopy (FLCS) like analysis to obtain clean correlation curves for both overlapping foci.

Accurate determination of the orientational distribution of a fluorescent molecule in a phospholipid membrane.

Orientation of lipophilic dye molecules within a biological membrane can report on the molecular environment, i.e., the physical and chemical properties of the surrounding membrane.

Molecular rheometry: direct determination of viscosity in Lo and Ld lipid phases via fluorescence lifetime imaging.

Understanding of cellular regulatory pathways that involve lipid membranes requires the detailed knowledge of their physical state and structure. However, mapping the viscosity and diffusion in the membranes of complex composition is currently a non-trivial technical challenge. We report fluorescence lifetime spectroscopy and imaging (FLIM) of a meso-substituted BODIPY molecular rotor localised in the leaflet of model membranes of various lipid compositions.