Reduction and fixation of glenoid cavity fractures using arthroscopy cause little surgical trauma, allowing the complementary diagnosis and treatment of potentially associated injuries (either capsular, ligamentous or tendon lesions) with promising outcomes. The authors report a case of Ideberg type III glenoid fracture with a distal clavicle fracture which underwent percutaneous reduction and bone fixation (with Kirschner wires) using an arthroscopic technique. We describe the procedure and the outcomes after 18 years of follow-up.
View Article and Find Full Text PDFRapid prototyping technology, known as three-dimensional (3D) printing, and its use in the medical field are advancing. Studies on severe bone deformity treatment with 3D printing showed benefits in postoperative outcomes thanks to this technology. Even so, preoperative planning guidance for surgeons is lacking.
View Article and Find Full Text PDFDue to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Forty cubic-shaped objects were printed with PLA material.
View Article and Find Full Text PDFCellular homeostasis and stress survival requires maintenance of the proteome and suppression of proteotoxicity. Molecular chaperones promote cell survival through repair of misfolded proteins and cooperation with protein degradation machines to discard terminally damaged proteins. Hsp70 family members play an essential role in cellular protein metabolism by binding and releasing non-native proteins to facilitate protein folding, refolding, and degradation.
View Article and Find Full Text PDFRev Bras Ortop (Sao Paulo)
August 2024
As in many areas of knowledge, rapid prototyping technology or additive manufacturing, popularly known as three-dimensional (3D) printing, has been gaining ground in medicine in recent years, with different applications. Numerous are the benefits of this science in orthopedic surgery, by allowing the conversion of imaging tests into 3D models. Therefore, the aim of the present study is to describe a practical step-by-step for the printing of parts from patient imaging.
View Article and Find Full Text PDFObjectives: To evaluate the tomographic distance between the sternoclavicular joints and the nearest hilar structures.
Methods: Computed tomography images (axial and sagittal slices) in 120 healthy individuals (60 men and 60 women) between 18 and 60 years old were prospectively analyzed. The distances from both sternoclavicular joints to the respective brachiocephalic veins, trachea, esophagus, and lung apexes were measured and related to age, sex, and body mass index.
Objective: To evaluate the biomechanical properties of the fixation of the long head of the biceps brachii into the humeral bone with suture anchors, interference screw, and soft tissue suture, comparing strength, highest traction load, and types of fixation failure.
Methods: Thirty fresh-frozen sheep shoulders were used, separated into three groups of ten for each technique. After fixation, the tendons were subjected to longitudinal continuous loading, obtaining load-to-failure (N) and displacement (mm).
Background: Glenoid erosion is one of the main concerns in shoulder hemiarthroplasty. The goal of this study was to quantify glenoid erosion and to identify risk factors in patients with humeral hemiarthroplasty.
Methods: There were 118 shoulders in 113 patients available for a standardized retrospective review.
To accomplish its crucial role, mitochondria require proteins that are produced in the cytosol, delivered by cytosolic Hsp90, and translocated to its interior by the translocase outer membrane (TOM) complex. Hsp90 is a dimeric molecular chaperone and its function is modulated by its interaction with a large variety of co-chaperones expressed within the cell. An important family of co-chaperones is characterized by the presence of one TPR (tetratricopeptide repeat) domain, which binds to the C-terminal MEEVD motif of Hsp90.
View Article and Find Full Text PDFSiva1 protein interacts with tumor protein p53 and with the member of the tumor necrosis factor receptor superfamily, stathmin, among others. These proteins are related to several pathways involved in cancer and are therefore strong candidate targets for drug design. This study aimed to characterize the biophysical properties of Siva 1 C- terminal domain to contribute to the discovery of new target directed drugs.
View Article and Find Full Text PDFAn Acad Bras Cienc
August 2015
The process of folding is a seminal event in the life of a protein, as it is essential for proper protein function and therefore cell physiology. Inappropriate folding, or misfolding, can not only lead to loss of function, but also to the formation of protein aggregates, an insoluble association of polypeptides that harm cell physiology, either by themselves or in the process of formation. Several biological processes have evolved to prevent and eliminate the existence of non-functional and amyloidogenic aggregates, as they are associated with several human pathologies.
View Article and Find Full Text PDFProteins participate in almost every cell physiological function, and to do so, they need to reach a state that allows its function by folding and/or exposing surfaces of interactions. Spontaneous folding in the cell is in general hindered by its crowded and viscous environment, which favors misfolding and nonspecific and deleterious self-interactions. To overcome this, cells have a system, in which Hsp70 and Hsp90 play a central role to aid protein folding and avoid misfolding.
View Article and Find Full Text PDFThe human mitochondrial Hsp70, also called mortalin, is of considerable importance for mitochondria biogenesis and the correct functioning of the cell machinery. In the mitochondrial matrix, mortalin acts in the importing and folding process of nucleus-encoded proteins. The in vivo deregulation of mortalin expression and/or function has been correlated with age-related diseases and certain cancers due to its interaction with the p53 protein.
View Article and Find Full Text PDFCellular homeostasis and stress survival requires maintenance of the proteome and suppression of proteotoxicity. Molecular chaperones promote cell survival through repair of misfolded proteins and cooperation with protein degradation machines to discard terminally damaged proteins. Hsp70 family members play an essential role in cellular protein metabolism by binding and releasing nonnative proteins to facilitate protein folding, refolding and degradation.
View Article and Find Full Text PDFXAC0610, from Xanthomonas citri subsp. citri, is a large multi-domain protein containing one GAF (cGMP-specific phosphodiesterases, adenylyl cyclases and FhlA) domain, four PAS (Per-Arnt-Sim) domains and one GGDEF domain. This protein has a demonstrable in vivo and in vitro diguanylate cyclase (DGC) activity that leads to the production of cyclic di-GMP (c-di-GMP), a ubiquitous bacterial signaling molecule.
View Article and Find Full Text PDFThe p23 protein is a chaperone widely involved in protein homeostasis, well known as an Hsp90 co-chaperone since it also controls the Hsp90 chaperone cycle. Human p23 includes a β-sheet domain, responsible for interacting with Hsp90; and a charged C-terminal region whose function is not clear, but seems to be natively unfolded. p23 can undergo caspase-dependent proteolytic cleavage to form p19 (p231-142), which is involved in apoptosis, while p23 has anti-apoptotic activity.
View Article and Find Full Text PDFFocal adhesion kinase (FAK) contributes to cellular homeostasis under stress conditions. Here we show that αB-crystallin interacts with and confers protection to FAK against calpain-mediated proteolysis in cardiomyocytes. A hydrophobic patch mapped between helices 1 and 4 of the FAK FAT domain was found to bind to the β4-β8 groove of αB-crystallin.
View Article and Find Full Text PDFBackground: Hsp90 is a molecular chaperone essential for cell viability in eukaryotes that is associated with the maturation of proteins involved in important cell functions and implicated in the stabilization of the tumor phenotype of various cancers, making this chaperone a notably interesting therapeutic target. Celastrol is a plant-derived pentacyclic triterpenoid compound with potent antioxidant, anti-inflammatory and anticancer activities; however, celastrol's action mode is still elusive.
Results: In this work, we investigated the effect of celastrol on the conformational and functional aspects of Hsp90α.
We investigated the folding of the 70 kDa human cytosolic inducible protein (Hsp70) in vitro using high hydrostatic pressure as a denaturing agent. We followed the structural changes in Hsp70 induced by high hydrostatic pressure using tryptophan fluorescence, molecular dynamics, circular dichroism, high-performance liquid chromatography gel filtration, dynamic light scattering, ATPase activity, and chaperone activity. Although monomeric, Hsp70 is very sensitive to hydrostatic pressure; after pressure had been removed, the protein did not return to its native sate but instead formed oligomeric species that lost chaperone activity but retained ATPase activity.
View Article and Find Full Text PDFProteomics
April 2014
The main goal of this work is to evaluate some differential protein species in transgenic (T) and nontransgenic (NT) Arabidopsis thaliana plants after their cultivation in the presence or absence of sodium selenite. The transgenic line was obtained through insertion of CaMV 35S controlling nptII gene. Comparative proteomics through 2D-DIGE is carried out in four different groups (NT × T; NT × Se-NT (where Se is selenium); Se-NT × Se-T, and T × Se-T).
View Article and Find Full Text PDFUnlabelled: Hsp70 cycles from an ATP-bound state, in which the affinity for unfolded polypeptides is low, to an ADP-bound state, in which the affinity for unfolded polypeptides is high, to assist with cell proteostasis. Such cycling also depends on co-chaperones because these proteins control both the Hsp70 ATPase activity and the delivery of unfolded polypeptide chains. Although it is very important, structural information on the entire protein is still scarce.
View Article and Find Full Text PDFObjective: To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships.
Methods: Eleven cadaver knees were dissected in order to study the anatomy and take measurements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions.
Hsp90s are involved in several cellular processes, such as signaling, proteostasis, epigenetics, differentiation and stress defense. Although Hsp90s from different organisms are highly similar, they usually have small variations in conformation and function. Thus, the characterization of different Hsp90s is important to gain insight into the structure-function relationship that makes these chaperones key regulators in protein homeostasis.
View Article and Find Full Text PDF