Comparison of Pelvic Landmarks for Leg Length Discrepancy Measurement With Robotic Arm-Assisted Total Hip Arthroplasty.

Background: Leg length discrepancy (LLD) is a common complication after total hip arthroplasty (THA) leading to significant morbidity and dissatisfaction for patients. A popular system for robotic arm-assisted THA utilizes preoperative computed tomography (CT) scans for surgical planning. Accurate measurement of leg length is crucial for restoring appropriate patient anatomy during the procedure.

The use of a laminar spreader for the reduction of extra-articular distal radius fractures: A technical trick.

Extra-articular distal radius fractures are often accompanied with shortening, loss of radial height, and radial displacement of the articular segment relative to the shaft of the radius, all seen in the coronal plane. Reduction can be somewhat challenging when reliance on traction and ligamentotaxis fails, especially in subacute or osteoporotic fractures. In this technical report, we describe a technique where application of a laminar spreader between the radius and the ulna in the metaphyseal region can easily reduce the fracture and help attain anatomic alignment in the coronal plane.

Salvage of Bone Transport with the Induced Membrane Technique in an Open Tibia Fracture with a Segmental Defect: A Case Report.

Case: A 29-year-old man with an open tibia fracture and a 15-cm bone defect was treated with irrigation, debridement, intramedullary nailing, soft-tissue flap, and bone transport with a frame over the nail. He developed osteomyelitis of his bone transport segment close to docking, which required bone resection and an induced membrane technique to salvage his transport segment and achieve union.

Conclusions: This report illustrates the combined use of bone transport and induced membrane technique to achieve union in a 15-cm tibial defect.

Robotic Arm-Assisted Total Hip Arthroplasty to Correct Leg Length Discrepancy in a Patient With Spinopelvic Obliquity.

Leg length discrepancy is not an uncommon result of total hip arthroplasty and a major cause of patient dissatisfaction. Spinopelvic obliquity is a less-recognized cause of limb length differences in patients undergoing total hip arthroplasty. The robotic arm has recently been introduced to enhance implant positioning during surgery and to achieve more predictable leg length and offset goals.

Clinical outcomes of Bryan cervical disc arthroplasty a prospective, randomized, controlled, single site trial with 48-month follow-up.

Study Design: Prospective, randomized, controlled. Level 1 evidence.

Objective: To report functional outcomes at 48 months follow-up on prospectively randomized patients to either the Bryan cervical disc prosthesis or anterior cervical discectomy and fusion (ACDF) at a single site.

A house divided: ceramide, sphingosine, and sphingosine-1-phosphate in programmed cell death.

Programmed cell death is an important physiological response to many forms of cellular stress. The signaling cascades that result in programmed cell death are as elaborate as those that promote cell survival, and it is clear that coordination of both protein- and lipid-mediated signals is crucial for proper cell execution. Sphingolipids are a large class of lipids whose diverse members share the common feature of a long-chain sphingoid base, e.

Sphingosine kinase-1 is cleaved by cathepsin B in vitro: identification of the initial cleavage sites for the protease.

Previous work has identified sphingosine kinase-1 (SK1) as a substrate for the cysteine protease cathepsin B in vitro. In this study, the mechanism of SK1 cleavage by cathepsin B was investigated. We identified two initial cleavage sites for the protease, the first at histidine 122 and the second at arginine 199.

Protein kinase C-induced activation of a ceramide/protein phosphatase 1 pathway leading to dephosphorylation of p38 MAPK.

Recently we showed that, in human breast cancer cells, activation of protein kinase C by 4beta-phorbol 12-myristate 13-acetate (PMA) produced ceramide formed from the salvage pathway (Becker, K. P., Kitatani, K.

Sphingosine kinase: biochemical and cellular regulation and role in disease.

Sphingolipids have emerged as molecules whose metabolism is regulated leading to generation of bioactive products including ceramide, sphingosine, and sphingosine-1-phosphate. The balance between cellular levels of these bioactive products is increasingly recognized to be critical to cell regulation; whereby, ceramide and sphingosine cause apoptosis and growth arrest phenotypes, and sphingosine-1-phosphate mediates proliferative and angiogenic responses. Sphingosine kinase is a key enzyme in modulating the levels of these lipids and is emerging as an important and regulated enzyme.

Modulation of total Akt kinase by increased expression of a single isoform: requirement of the sphingosine-1-phosphate receptor, Edg3/S1P3, for the VEGF-dependent expression of Akt3 in primary endothelial cells.

Akt kinase is an important downstream effector of VEGF in primary endothelial cells (EC), promoting angiogenesis by increased cellular survival, motility and tubulogenesis. Akt1 is the founding member of a family of serine threonine kinases thought to have overlapping function. We sought to determine if other Akt family members were also regulated by VEGF in EC.

Oxidized LDL immune complexes induce release of sphingosine kinase in human U937 monocytic cells.

The transformation of macrophages into foam cells is a critical event in the development of atherosclerosis. The most studied aspect of this process is the uptake of modified LDL through the scavenger receptors. Another salient aspect is the effect of modified LDL immune complexes on macrophages activation and foam cell formation.

Loss of sphingosine kinase-1 activates the intrinsic pathway of programmed cell death: modulation of sphingolipid levels and the induction of apoptosis.

Activation of sphingosine kinase-1 (SK1) by overexpression or agonist stimulation promotes cell proliferation, survival, and anti-apoptosis. Studies on the function of endogenous SK1 are lacking. Endogenous SK1 has been shown to be down-regulated under stress, and knockdown of the enzyme reduces the percentage of viable MCF-7 breast cancer cells (Taha, T.

The coordination of prostaglandin E2 production by sphingosine-1-phosphate and ceramide-1-phosphate.

The ability of pro-inflammatory cytokines such as interleukin-1beta (IL-1beta) to induce the major inflammatory mediator prostaglandin (PG) E(2) depends on the activation of two rate-limiting enzymes, phospholipase A(2) (PLA(2)) and cyclooxygenase 2 (COX-2). PLA(2) acts to generate arachidonic acid, which serves as the precursor substrate for COX-2 in the metabolic pathway leading to PGE(2) production. However, less is known about the mechanisms that coordinate the regulation of these two enzymes.

Tumor necrosis factor induces the loss of sphingosine kinase-1 by a cathepsin B-dependent mechanism.

Sphingosine kinase-1 (SK1) has emerged as a key component of cytokine responses, including roles in apoptosis, yet the specific mechanisms by which cytokines regulate SK1 in the apoptotic responses have not been studied. In this study, we show that prolonged treatment of MCF-7 cells with tumor necrosis factor (TNF) induces a dose- and time-dependent decrease in SK1 protein. Inhibition of the upstream caspase 8 by IETD significantly rescued TNF effects on SK1, yet the caspase 7 inhibitor DEVD failed to have any effect, suggesting that the decline in SK1 occurs downstream of the initiator caspase but upstream of the effector caspase.

Sphingosine-1-phosphate receptors: receptor specificity versus functional redundancy.

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that has recently been shown to bind cell surface S1P receptors (previously called endothelial differentiation gene (Edg) receptors), which are members of the G-protein-coupled family of receptors. Signaling via S1P is a complex process, as cells usually express a number of these receptors on their surfaces. Many of the S1P receptors share common G-proteins, invoking the question of how these receptors are specific in their actions.

Down-regulation of sphingosine kinase-1 by DNA damage: dependence on proteases and p53.

Sphingosine kinase 1 (SK1), a key enzyme in sphingosine 1-phosphate (S1P) synthesis, regulates various aspects of cell behavior, including cell survival and proliferation. DNA damaging anti-neoplastic agents have been shown to induce p53, ceramide levels, and apoptosis; however, the effects of anti-neoplastic agents on SK have not been assessed. In this study, we investigated the effects of a DNA damaging agent, actinomycin D (Act D), on the function of sphingosine kinase (SK1).