Inflammatory predictors of ongoing pain 2 years following knee replacement surgery.

Introduction: The prevalence of unrelieved pain following total knee arthroplasty (TKA) is substantial.

Objective: We asked if cytokine markers of inflammation in preoperative serum or knee synovial fluid (SF) would predict pain 2 years following TKA.

Methods: Demographic data and functional outcomes were recorded at baseline and 2 years with the WOMAC index.

Microarray analysis of the infrapatellar fat pad in knee osteoarthritis: relationship with joint inflammation.

Objective: To examine differences in genes involved in fat metabolism, energy homeostasis, adipogenesis, and inflammation between endstage and early-stage knee osteoarthritis (OA) infrapatellar fat pads (IFP).

Methods: Twenty-nine endstage and 5 early-stage primary OA IFP were harvested at knee surgery. Total RNA was extracted, labeled, and hybridized to whole-genome expression arrays.

The synovial fluid adiponectin-leptin ratio predicts pain with knee osteoarthritis.

The relationship between adipokines, such as leptin and adiponectin, and cartilage degeneration is being increasingly recognized. We asked what the relationship is between these hormones and patient-reported knee osteoarthritis (OA) pain. We collected demographic data, Short Form McGill Pain scores, Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scores, and synovial fluid (SF) samples from 60 consecutive patients with severe knee OA at the time of joint replacement surgery.

ChIPing away at global transcriptional regulation.

The regulation of gene expression impacts all aspects of cell biology and biochemistry. As we gain a greater understanding of the mechanisms involved in this process, we also begin to unveil its complexities. The delicate balancing act played out by the multitude of DNA interacting proteins can easily become unhinged.

Relationship between body habitus and joint leptin levels in a knee osteoarthritis population.

Synovial fluid (SF) leptin has been shown to have an association with cartilage degeneration. Our objective was to examine the relationship between different measures of body habitus and SF leptin levels in an end-stage knee osteoarthritis (OA) population. Sixty consecutive patients with knee OA were surveyed prior to surgery for demographic data.

Identification and characterization of a novel gene, dapr, involved in skeletal muscle differentiation and protein kinase B signaling.

The phosphatidylinositol 3-kinase (PI3K) signaling pathway has been associated with a variety of cellular functions ranging from cell cycle regulation to tissue development. Although years of research have extensively characterized this signaling pathway, little is known as to how specific cellular events are coordinated by its activation. Here we demonstrate that Dapr (differentiation-associated protein), a novel protein, appears to focus one aspect of this pathway by acting as a putative scaffold protein during skeletal muscle differentiation.

Muscling in on microarrays.

Adaptations that are the result of exercise require a multitude of changes at the level of gene expression. The mechanisms involved in regulating these changes are many, and can occur at various points in the pathways that affect gene expression. The completion of the human genome sequence, along with the genomes of related species, has provided an enormous amount of information to help dissect and understand these pathways.

CpG Island microarray probe sequences derived from a physical library are representative of CpG Islands annotated on the human genome.

An effective tool for the global analysis of both DNA methylation status and protein-chromatin interactions is a microarray constructed with sequences containing regulatory elements. One type of array suited for this purpose takes advantage of the strong association between CpG Islands (CGIs) and gene regulatory regions. We have obtained 20,736 clones from a CGI Library and used these to construct CGI arrays.

Cardioprotective stress response in the human fetal heart.

Objective: We propose that the fetal heart is highly resilient to hypoxic stress. Our objective was to elucidate the human fetal gene expression profile in response to simulated ischemia and reperfusion to identify molecular targets that account for the innate cardioprotection exhibited by the fetal phenotype.

Methods: Primary cultures of human fetal cardiac myocytes (gestational age, 15-20 weeks) were exposed to simulated ischemia and reperfusion in vitro by using a simulated ischemic buffer under anoxic conditions.

Identification of MEF2-regulated genes during muscle differentiation.

Although a great deal has been elucidated concerning the mechanisms regulating muscle differentiation, little is known about transcription factor-specific gene regulation. Our understanding of the genetic mechanisms regulating cell differentiation is quite limited. Much of what has been defined centers on regulatory signaling cascades and transcription factors.

Gene expression profiles in children undergoing cardiac surgery for right heart obstructive lesions.

Background: The global myocardial stress response during cardiac surgery has not been systematically studied, nor is it known whether the response of the neonatal myocardium is intrinsically different from that of older children. To determine the age-related molecular basis of this response, we conducted microarray-based differential gene expression profiling on right ventricular tissue samples acquired in patients of varying ages with right ventricular outflow tract obstruction.

Methods: We studied gene expression profiles in 24 patients during operations for lesions involving right ventricular outflow tract obstruction age stratified into group I (7 patients, aged 5 to 66 days; mean, 30 days) and group II (17 patients, aged 4 months to 12.

Transcriptional activation of immediate-early gene ETR101 by human T-cell leukaemia virus type I Tax.

Human T-cell leukaemia virus type I (HTLV-I) Tax regulates viral and cellular gene expression through interactions with multiple cellular transcription pathways. This study describes the finding of immediate-early gene ETR101 expression in HTLV-I-infected cells and its regulation by Tax. ETR101 was persistently expressed in HTLV-I-infected cells but not in HTLV-I uninfected cells.

Constitutive p38HOG mitogen-activated protein kinase activation induces permanent cell cycle arrest and senescence.

Cellular senescence, initially observed during subculturing of normal diploid fibroblasts, can also be induced by chronic exposure to cellular stress, such as UV light, oxidative stress, or DNA damaging agents. Here we demonstrate that stable expression of an activated form of MKK6 (MKK6EE), a direct activator of the stress-induced p38(HOG) mitogen-activated protein kinase pathway, is sufficient for inducing features of senescence including a flattened, vacuolated, and irregular morphology, staining for acidic beta-galactosidase, and accumulation of age-associated pigments. Consistent with the senescent phenotype, p38(HOG) activation induces a G(1) cell cycle arrest, which is permanent and irreversible after 4 days.