Evoked Compound Action Potentials Reveal Spinal Cord Dorsal Column Neuroanatomy.

Introduction: The electrically evoked compound action potential (ECAP) is a measure of the response from a population of fibers to an electrical stimulus. ECAPs can be assessed during spinal cord stimulation (SCS) to elucidate the relationship between stimulation, electrophysiological response, and neuromodulation. This has consequences for the design and programming of SCS devices.

Feasibility, Validity, and Responsiveness of Self-Report and Objective Measures of Physical Activity in Patients With Chronic Pain.

Background: Accurate tools for measuring physical activity are important for monitoring patients with chronic pain. However, these tools have not been properly validated in this population.

Objective: To determine the suitability of two physical activity measures for use in chronic pain populations.

The adolescent idiopathic scoliotic IVD displays advanced aggrecanolysis and a glycosaminoglycan composition similar to that of aged human and ovine IVDs.

Purpose: The present study was designed to ascertain how altered biomechanics in adolescent idiopathic scoliotic (AIS) intervertebral discs (IVDs) affected tissue compositions and aggrecan processing compared to age matched and aged human IVDs. Newborn, 2- and 10-year-old ovine IVDs were also examined.

Methods: Aggrecan populations were separated by Sepharose CL2B chromatography, composite agarose polyacrylamide gel electrophoresis (CAPAGE) and identified by immunoblotting.

Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study.

Objectives: Conventional spinal cord stimulation (SCS) delivers a fixed-input of energy into the dorsal column. Physiologic effects such as heartbeat, respiration, spinal cord movement, and history of stimulation can cause both the perceived intensity and recruitment of stimulation to increase or decrease, with clinical consequences. A new SCS system controls stimulation dose by measuring the recruitment of fibers in the dorsal column and by using the amplitude of the evoked compound action potentials (ECAPs) to maintain stimulation within an individualized therapeutic range.

Development of the Brazilian Portuguese version of the Achilles Tendon Total Rupture Score (ATRS BrP): a cross-cultural adaptation with reliability and construct validity evaluation.

Background: There is a need for a patient-relevant instrument to evaluate outcome after treatment in patients with a total Achilles tendon rupture. The purpose of this study was to undertake a cross-cultural adaptation of the Achilles Tendon Total Rupture Score (ATRS) into Brazilian Portuguese, determining the test-retest reliability and construct validity of the instrument.

Methods: A five-step approach was used in the cross-cultural adaptation process: initial translation (two bilingual Brazilian translators), synthesis of translation, back-translation (two native English language translators), consensus version and evaluation (expert committee), and testing phase.

Planned early delivery versus expectant management of the term suspected compromised baby for improving outcomes.

Background: Fetal compromise in the term pregnancy is suspected when the following clinical indicators are present: intrauterine growth restriction (IUGR), decreased fetal movement (DFM), or when investigations such as cardiotocography (CTG) and ultrasound reveal results inconsistent with standard measurements. Pathological results would necessitate the need for immediate delivery, but the management for 'suspicious' results remains unclear and varies widely across clinical centres. There is clinical uncertainty as to how to best manage women presenting with a suspected term compromised baby in an otherwise healthy pregnancy.

Peripheral injury of pelvic visceral sensory nerves alters GFRα (GDNF family receptor alpha) localization in sensory and autonomic pathways of the sacral spinal cord.

GDNF (glial cell line-derived neurotrophic factor), neurturin and artemin use their co-receptors (GFRα1, GFRα2 and GFRα3, respectively) and the tyrosine kinase Ret for downstream signaling. In rodent dorsal root ganglia (DRG) most of the unmyelinated and some myelinated sensory afferents express at least one GFRα. The adult function of these receptors is not completely elucidated but their activity after peripheral nerve injury can facilitate peripheral and central axonal regeneration, recovery of sensation, and sensory hypersensitivity that contributes to pain.

Chondroitin sulphate and heparan sulphate sulphation motifs and their proteoglycans are involved in articular cartilage formation during human foetal knee joint development.

Novel sulphation motifs within the glycosaminoglycan chain structure of chondroitin sulphate (CS) containing proteoglycans (PGs) are associated with sites of growth, differentiation and repair in many biological systems and there is compelling evidence that they function as molecular recognition sites that are involved in the binding, sequestration or presentation of soluble signalling molecules (e.g. morphogens, growth factors and cytokines).

Compound action potentials recorded in the human spinal cord during neurostimulation for pain relief.

Electrical stimulation of the spinal cord provides effective pain relief to hundreds of thousands of chronic neuropathic pain sufferers. The therapy involves implantation of an electrode array into the epidural space of the subject and then stimulation of the dorsal column with electrical pulses. The stimulation depolarises axons and generates propagating action potentials that interfere with the perception of pain.

Induction of c-Fos and zif268 in the nociceptive amygdala parallel abstinence hyperalgesia in rats briefly exposed to morphine.

Opioid-induced analgesia can be followed by spontaneous pain in humans, and hyperalgesia in rodents. In this study, opioid-induced hyperalgesia was measured by the tail-flick test when acute abstinence was precipitated by administering naloxone to drug naive rats that had experienced morphine analgesia for only 30 min. In a further experiment, the drug treatment that previously caused opioid-induced hyperalgesia was found to increase neurons expressing nuclear c-Fos or zif268 proteins in extended amygdalar regions targeted by projections of the ascending spino-parabrachio-amygdaloid nociceptive pathway.

The structure, location, and function of perlecan, a prominent pericellular proteoglycan of fetal, postnatal, and mature hyaline cartilages.

The aim of this study was to immunolocalize perlecan in human fetal, postnatal, and mature hyaline cartilages and to determine information on the structure and function of chondrocyte perlecan. Perlecan is a prominent component of human fetal (12-14 week) finger, toe, knee, and elbow cartilages; it was localized diffusely in the interterritorial extracellular matrix, densely in the pericellular matrix around chondrocytes, and to small blood vessels in the joint capsules and perichondrium. Aggrecan had a more intense distribution in the marginal regions of the joint rudiments and in para-articular structures.

Transfusion-related acute lung injury: a literature review.

Transfusion-related acute lung injury (TRALI) is a serious and potentially fatal complication of transfusion of blood and blood components. TRALI is under-diagnosed and under-reported because of a lack of awareness. A number of models have been proposed to explain the pathogenesis of TRALI: an antibody mediated model; a two-event biologically active mediator model; and a combined model.

Perlecan displays variable spatial and temporal immunolocalisation patterns in the articular and growth plate cartilages of the ovine stifle joint.

Perlecan is a modular heparan sulphate and/or chondroitin sulphate substituted proteoglycan of basement membrane, vascular tissues and cartilage. Perlecan acts as a low affinity co-receptor for fibroblast growth factors 1, 2, 7, 9, binds connective tissue growth factor and co-ordinates chondrogenesis, endochondral ossification and vascular remodelling during skeletal development; however, relatively little is known of its distribution in these tissues during ageing and development. The aim of the present study was to immunolocalise perlecan in the articular and epiphyseal growth plate cartilages of stifle joints in 2-day to 8-year-old pedigree merino sheep.

Cytokine induced metalloproteinase expression and activity does not correlate with focal susceptibility of articular cartilage to degeneration.

Objective: To determine whether the focal susceptibility to cartilage degeneration in joints is related to a differential response to cytokine stimulation.

Methods: Compare aggrecan and collagen catabolism in in-vitro models of cartilage degradation induced by retinoic acid (RA), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF) and IL-1 plus oncostatin M (OSM). Glycosaminoglycan (GAG) and hydroxyproline (HyPro) quantification and Western immunoblot analyses of aggrecan and collagen degradation products were undertaken in explant cultures of normal cartilage from regions of equine joints with a known high and low susceptibility to degeneration in disease.

Histochemical visualization of the cartilage hyaladherins using a biotinylated hyaluronan oligosaccharide bioaffinity probe.

Hyaluronan (HA) binding proteins (HABPs) were localized in cartilaginous ovine tissues (articular cartilage, intervertebral disc) using a biotinylated HA (bHA) oligosaccharide bioaffinity probe. The bHA oligosaccharide probe was prepared by partial digestion of HA with ovine testicular hyaluronidase, and the oligosaccharides were labeled with biotin hydrazide and purified by a combination of aggrecan G1 domain and avidin affinity chromatography. Hyaladherins were prominently visualized in tissue sections using the bHA oligosaccharide probe as pericellular components in hypertrophic epiphyseal and vertebral growth plate chondrocytes and in the enlarged cells of the cartilaginous end plate of the intervertebral disc.

Histological and immunohistological studies on cartilage.

The material properties of dense avascular connective tissues such as cartilage present unique challenges to the development of any prospective histological procedures. This chapter documents some of the protocols we have developed in our laboratories for the histological and immunohistochemical evaluation of extracellular-matrix components in normal and pathological articular cartilage. Illustrative examples are provided of specimens from an ovine meniscectomy model of osteoarthritis.

The arterial tourniquet: pathophysiological consequences and anaesthetic implications.

The arterial tourniquet is widely used in upper and lower extremity surgery and in intravenous regional anaesthesia. The local and systemic physiological effects and the anaesthetic implications are reviewed. Localised complications result from either tissue compression beneath the cuff or tissue ischaemia distal to the tourniquet.

The effect of diclofenac on the expression of spinal cord c-fos-like immunoreactivity after ischemia-reperfusion-induced acute hyperalgesia in the rat tail.

Ischemia-reperfusion of the rat tail for 20 min induces local acute hyperalgesia of approximately 1-h duration. We studied how this stimulus affected the expression of c-fos-like immunoreactivity (c-fos-LI) labeling of neurons of the sacral spinal cord, and how diclofenac pretreatment influenced the outcome. After ischemia, the number of c-fos-LI-labeled neurons was significantly increased when assessed at 60, 90, and 120 min after reperfusion (to 183%, 283%, and 164% of control, respectively; all P < 0.

Pathogenesis of abdominal aortic aneurysms: possible role of differential production of proteoglycans by smooth muscle cells.

Purpose: In vivo and in vitro observations strongly suggest that marked differences exist in the phenotype, growth, and matrix-producing capabilities of distinct smooth muscle cell subpopulations. An earlier study from our laboratory showed differences in matrix metalloproteinase expression patterns in cultures of medial smooth muscle cells from tissue affected by abdominal aortic aneurysm (AAA) or atherosclerotic occlusive disease and from normal arterial tissue. In this study we were interested in ascertaining whether smooth muscle cells from the same sample groups also synthesized different proteoglycan profiles that correlated with vascular disease.

Factors influencing ketorolac-associated perioperative renal dysfunction.

Unlabelled: Nonsteroidal antiinflammatory drugs (NSAIDs) are useful for the treatment of postoperative pain, but there is continuing concern about adverse effects on renal function. We studied the renal effects of ketorolac in an animal model using Fischer 344 rats undergoing isoflurane anesthesia and laparotomy. Treatment groups--control (C), ketorolac (5 mg x kg(-1) x d(-1)) (K), large-dose ketorolac (15 mg x kg(-1) x d(-1)) (KH), dehydration-ketorolac (5 mg x kg(-1) x d(-1)) (DK), gentamicin (20 mg x kg(-1) x d(-1)) (G), and gentamicin (20 mg x kg(-1) x d(-1)) with ketorolac (5 mg x kg(-1) x d(-1)) (GK)--each comprised 10 animals.

Detection of aggregatable proteoglycan populations by affinity blotting using biotinylated hyaluronan.

Proteoglycans (PGs) were extracted from a range of cartilaginous ovine connective tissues using 4 M GuHCl and separated by composite agarose polyacrylamide gel electrophoresis. Individual PG populations resolved by this electrophoretic system were identified in toluidine blue and Stains-All stained gel segments and also by conventional immunoblotting using a range of monoclonal antibodies to defined PG epitopes. These PG species were compared with aggregatable PG populations identified by affinity blotting using a biotinylated hyaluronan, and an avidin alkaline phosphatase/nitro blue tetrazolium 5-bromo-4-chloro indolyl phosphate detection system.

A solid phase enzyme linked immunofiltration assay for secretory leucocyte proteinase inhibitor.

A solid phase enzyme linked immunosorbent filtration assay (ELIFA) has been developed for secretory leucocyte proteinase inhibitor (SLPI) utilising polyclonal anti-recombinant SLPI (anti-rSLPI) and polyclonal anti-bronchial mucus proteinase inhibitor (anti-BLPI) IgG samples. Millipore HATF nitrocellulose 96-well plates were used as receptacles for the assay and a commercial goat anti-rabbit IgG alkaline phosphatase conjugate was used as a secondary antibody for quantitation of levels of primary antibodies bound to rSLPI in the plate wells. Antigen bound to the HATF plates efficiently and the washing/blocking steps were simplified by vacuum filtration of samples resulting in a rapid and convenient assay system.