Vascular and nerve biomarkers in thigh skin biopsies differentiate painful from painless diabetic peripheral neuropathy.

Background: Identifying distinct mechanisms and biomarkers for painful diabetic peripheral neuropathy (DPN) is required for advancing the treatment of this major global unmet clinical need. We previously provided evidence in calf skin biopsies that disproportion between reduced sensory small nerve fibers and increased blood vessels may distinguish painful from non-painful DPN. We proposed that overexposure of the reduced nerve fibers in DPN to increased hypoxemia-induced vasculature and related algogenic factors, e.

Reversing painful and non-painful diabetic neuropathy with the capsaicin 8% patch: Clinical evidence for pain relief and restoration of function nerve fiber regeneration.

Introduction: Current oral treatments for pain in diabetic peripheral neuropathy (DPN) do not affect the progression of DPN i.e., "disease modification.

Nerve and Vascular Biomarkers in Skin Biopsies Differentiate Painful From Painless Peripheral Neuropathy in Type 2 Diabetes.

Painful diabetic peripheral neuropathy can be intractable with a major impact, yet the underlying pain mechanisms remain uncertain. A range of neuronal and vascular biomarkers was investigated in painful diabetic peripheral neuropathy (painful-DPN) and painless-DPN and used to differentiate painful-DPN from painless-DPN. Skin biopsies were collected from 61 patients with type 2 diabetes (T2D), and 19 healthy volunteers (HV).

Capsaicin 8% Patch Treatment in Non-Freezing Cold Injury: Evidence for Pain Relief and Nerve Regeneration.

Neuropathic pain associated with Non-freezing Cold Injury (NFCI) is a major burden to military service personnel. A key feature of NFCI is reduction of the intra-epidermal nerve fibre density in skin biopsies, in keeping with painful neuropathy. Current oral treatments are generally ineffective and have undesirable side effects.

The Influence of Time of Season on Injury Rates and the Epidemiology of Canadian Football Injuries.

Objective: To describe injury rates and injury patterns in the Canadian Football League (CFL) according to time during the season, player position, injury type, and injury location.

Design: Prospective, cohort study.

Setting And Participants: Eight seasons from CFL injury surveillance database.

Rational treatment of chemotherapy-induced peripheral neuropathy with capsaicin 8% patch: from pain relief towards disease modification.

Purpose: Chemotherapy-induced peripheral neuropathy (CIPN) with associated chronic pain is a common and disabling condition. Current treatments for neuropathic pain in CIPN are largely ineffective, with unfavorable side-effects. The capsaicin 8% patch (capsaicin 179 mg patch) is approved for the treatment of neuropathic pain: a single topical cutaneous application can produce effective pain relief for up to 12 weeks.

Granulocyte-macrophage colony-stimulating factor receptor expression in clinical pain disorder tissues and role in neuronal sensitization.

Introduction: Granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR) is highly expressed in peripheral macrophages and microglia, and is involved in arthritis and cancer pain in animal models. However, there is limited information on GM-CSFR expression in human central nervous system (CNS), peripheral nerves, or dorsal root ganglia (DRG), particularly in chronic pain conditions.

Objectives: Immunohistochemistry was used to quantify GM-CSFR expression levels in human tissues, and functional sensory effects of GM-CSF were studied in cultured DRG neurons.

Trench Foot or Non-Freezing Cold Injury As a Painful Vaso-Neuropathy: Clinical and Skin Biopsy Assessments.

Background: Trench foot, or non-freezing cold injury (NFCI), results from cold exposure of sufficient severity and duration above freezing point, with consequent sensory and vascular abnormalities which may persist for years. Based on observations of Trench foot in World War II, the condition was described as a vaso-neuropathy. While some reports have documented nerve damage after extreme cold exposure, sensory nerve fibres and vasculature have not been assessed with recent techniques in NFCI.

Decrease in articular hypoxia and synovial blood flow at early time points following infliximab and etanercept treatment in rheumatoid arthritis.

Objectives: An important feature of rheumatoid arthritis (RA) is hypoxia-driven synovial angiogenesis, but the relationship between change in vascularity, as measured by power Doppler ultrasound (PDUS), and oxygen tensions is unaddressed.

Methods: Metacarpophalangeal (MCP) joint PDUS was assessed in 23 patients with RA, alongside arthroscopic synovitis and oxygen tension measurements, at baseline and 4 weeks after anti-tumour necrosis factor (TNF) inhibitors.

Results: Anti-TNF reduced PDUS scores, which were negatively correlated with rise in oxygen tensions.

C1q Modulates the Response to TLR7 Stimulation by Pristane-Primed Macrophages: Implications for Pristane-Induced Lupus.

The complement component C1q is known to play a controversial role in the pathogenesis of systemic lupus erythematosus, but the underlying mechanisms remain poorly understood. Intraperitoneal injection of pristane induces a lupus-like syndrome whose pathogenesis implicates the secretion of type I IFN by CD11b(+) Ly6C(high) inflammatory monocytes in a TLR7-dependent fashion. C1q was also shown to influence the secretion of IFN-α.

Ultrasonographic measures of synovitis in an early phase clinical trial: a double-blind, randomised, placebo and comparator controlled phase IIa trial of GW274150 (a selective inducible nitric oxide synthase inhibitor) in rheumatoid arthritis.

Objectives: To test the sensitivity to change of ultrasonographic endpoints in early phase clinical trials in subjects with active rheumatoid arthritis (RA).

Methods: A double-blind, placebo and comparator controlled, randomised, two-centre study investigated the effect on synovial thickness and vascularity of 28 days repeat daily oral dosing of 60 mg of the inducible nitric oxide synthase inhibitor GW274150 or 7.5 mg prednisolone in RA.

Identification of citrullinated alpha-enolase as a candidate autoantigen in rheumatoid arthritis.

Antibodies against citrullinated proteins are highly specific for rheumatoid arthritis (RA), but little is understood about their citrullinated target antigens. We have detected a candidate citrullinated protein by immunoblotting lysates of monocytic and granulocytic HL-60 cells treated with peptidylarginine deiminase. In an initial screen of serum samples from four patients with RA and one control, a protein of molecular mass 47 kDa from monocytic HL-60s reacted with sera from the patients, but not with the serum from the control.

Human melanoblasts in culture: expression of BRN2 and synergistic regulation by fibroblast growth factor-2, stem cell factor, and endothelin-3.

The BRN2 transcription factor (POU3F2, N-Oct-3) has been implicated in development of the melanocytic lineage and in melanoma. Using a low calcium medium supplemented with stem cell factor, fibroblast growth factor-2, endothelin-3 and cholera toxin, we have established and partially characterised human melanocyte precursor cells, which are unpigmented, contain immature melanosomes and lack L-dihydroxyphenylalanine reactivity. Melanoblast cultures expressed high levels of BRN2 compared to melanocytes, which decreased to a level similar to that of melanocytes when cultured in medium that contained phorbol ester but lacked endothelin-3, stem cell factor and fibroblast growth factor-2.

Variations in cell density in the ganglion cell layer of the retina as a function of ocular pigmentation.

Ocular melanin regulates retinal development, including cell density gradients in the central retina, a region essential for normal visual acuity. In albinos this region is underdeveloped and peak cell numbers are reduced. It is not known whether there is a dosage relationship between pigmentation and the degree of this underdevelopment, as studies of the retinal effects of albinism have commonly used rodents.

Correlation between rod photoreceptor numbers and levels of ocular pigmentation.

Purpose: Ocular melanin synthesis modulates rod photoreceptor production, because in albino eyes, rod numbers are reduced by approximately 30%. In this study, rod numbers and ocular rhodopsin concentrations were measured in intermediate pigmentation phenotypes to determine whether proportional reductions in melanin are correlated with proportional changes in rod numbers. Further, patterns of cell production and death were examined around the time of birth, when rod production peaks, to determine whether there are abnormalities in these features associated with hypopigmentation.

Human melanoma progression in skin reconstructs : biological significance of bFGF.

Human skin reconstructs are three-dimensional in vitro models consisting of epidermal keratinocytes plated onto fibroblast-contracted collagen gels. Cells in skin reconstructs more closely recapitulate the in situ phenotype than do cells in monolayer culture. Normal melanocytes in skin reconstructs remained singly distributed at the basement membrane which separated the epidermis from the dermis.

Identification and characterization of a melanocyte-specific novel 65-kDa peripheral membrane protein.

In order to study proteins of the melanosome, we developed a panel of antisera against various protein fractions of melanosomes from B16 melanoma cells. An antiserum raised against a Triton X-100 insoluble fraction of melanosomes recognized a 65-kDa protein in melanocytes from mice homozygous for the buff mutation, but not in their wild type counterparts. Further studies were conducted using a specific, second generation antiserum raised against the purified protein.

Ex vivo study of skin phototypes.

We studied skin phototypes ex vivo to validate a model of epidermal reconstruction with melanocytes. We made autologous epidermal reconstructs with keratinocytes and melanocytes of healthy donors of skin phototypes I to VI. Keratinocytes and melanocytes were seeded on a dead de-epidermized dermis (Pruniéras type) at a 1:20 melanocyte/keratinocyte ratio.

EGF receptor expression and growth of psoriatic and normal human keratinocytes are modulated by 1.25 (OH)2-vitamin D3 ex vivo.

Calcitriol or 1.25 (OH)2-vitamin D3 is used in the treatment of psoriasis as an inhibitor of cell proliferation. We studied the action of calcitriol ex vivo on the growth of psoriatic and normal human keratinocytes, and on the expression of the EGF receptor.

Melanosomal and lysosomal alterations in murine melanocytes following transfection with the v-rasHa oncogene.

Melanomas exhibiting mutated ras genes are frequently invasive and amelanotic. Transfecting melanocytes with ras oncogenes causes transformation and a loss of visible pigmentation. We analyzed murine melanocytes rendered amelanotic by transfection with the v-rasHa oncogene.

Interaction of melanosomal proteins with melanin.

Melanin is deposited in melanosomes upon a proteinaceous matrix enveloped by a melanosomal membrane. Since melanin is highly detergent insoluble, we hypothesized that the detergent solubility of proteins of the melanosomal matrix might be inversely related to the state of melanosomal melanization. Immunoblotting analyses were performed on extracts of albino and black melanocytes to test this hypothesis.

Cultured human melanocytes respond to MSH peptides and ACTH.

Although the administration of melanocyte-stimulating hormone (MSH) peptides results in skin darkening in man, cultured human melanocytes have been reported to be unresponsive to these peptides. This may be a consequence of the conditions under which the cells were maintained in vitro, particularly the use of phorbol esters and cholera toxin as melanocyte mitogens. By culturing the cells in the absence of these additives, we demonstrate that alpha-MSH and its synthetic analogue Nle4DPhe7 alpha-MSH (NDP-MSH) induce dose-related increases in melanin content and tyrosinase activity and affect cell morphology in the majority of human melanocyte cultures.

Identification of a melanosomal matrix protein encoded by the murine si (silver) locus using "organelle scanning".

To identify a broad spectrum of melanosomal proteins, antisera were raised in rabbits against melanosomal protein fractions separated on the basis of their solubility in the nonionic detergent Triton X-114. Antisera against the different fractions each recognized a distinct set of bands when used for immunoblotting analysis with extracts of melanocytes cultured from wild-type black mice. Immunoblotting with antisera to whole melanosomes or to Triton X-114-soluble melanosomal proteins that segregated with the detergent phase gave identical patterns with protein extracts from melanocytes from wild-type mice and from mice homozygous for the si (silver) coat color mutation.