Search results for "Intradermal injection"
showing 7 items of 7 documents
Complex regional pain syndrome:intradermal injection of phenylephrine evokes pain and hyperalgesia in a subgroup of patients with upregulated α1-adre…
2018
The aim of this study was to determine whether upregulated cutaneous expression of α1-adrenoceptors (α1-AR) is a source of pain in patients with complex regional pain syndrome (CRPS). Immunohistochemistry was used to identify α1-AR on nerve fibres and other targets in the affected and contralateral skin of 90 patients, and in skin samples from 38 pain-free controls. The distribution of α1-AR was compared between patients and controls, and among subgroups of patients defined by CRPS duration, limb temperature asymmetry, and diagnostic subtype (CRPS I vs CRPS II). In addition, α1-AR expression was investigated in relation to pain and pinprick hyperalgesia evoked by intradermal injection of th…
Roles of capsaicin-insensitive nociceptors in cutaneous pain and secondary hyperalgesia.
2001
Polymodal nociceptors respond to mechanical, thermal and chemical stimuli. Whereas sensitivities to heat and to the irritant substance capsaicin have recently been linked via the properties of the vanilloid receptor type 1 receptor ion channel, sensitivity to noxious mechanical stimuli such as the pinpricks used in clinical neurology seems to be unrelated. We investigated the peripheral neural basis of pinprick pain using quantitative psychophysical techniques combined with selective conduction block by nerve compression and selective desensitization by topical capsaicin treatment. Complete A-fibre block by compression of the superficial radial nerve (criterion: loss of first pain sensation…
Alpha 1 adrenoceptor expression in skin, nerves and blood vessels of patients with painful diabetic neuropathy
2021
Abstract Diabetic neuropathy (dNP) patients often suffer from severe neuropathic pain. It was suggested that alpha-1 adrenoceptor (α1-AR) hyperresponsiveness contributes to pain in dNP. The aim of our study was to quantify α1-AR expression using immunohistochemistry in skin biopsies of nine patients with painful diabetic neuropathy compared to 10 healthy controls. Additionally, the association between α1-AR expression and activation with spontaneous and sympathetically maintained pain (SMP) induced by intradermal injection of the α1-agonist phenylephrine was investigated. For control purposes the α2-agonist clonidine was injected in a different session. We found that dermal nerve density wa…
Modulation of Contact Sensitivity Responses by Bacterial Superantigen
1995
Superantigens are potent modulators of the immune system, especially T cells. Therefore, we determined the influence of superantigens on the T-cell-mediated immune response, contact sensitivity. We chose the combination of staphylococcal enterotoxin B (SEB) as superantigen and 2,4-dinitrofluorbenzene (DNFB) as the contact sensitizer, because in BALB/c mice SEB reacts almost exclusively with V beta 8+ T cells, and these cells are capable of transferring contact sensitivity to DNFB from sensitized donors to naive syngeneic recipients. Pretreatment with a single intradermal injection of 50 ng SEB 24 h before DNFB exposure at the same site on the lower abdomen enhanced the induction of contact …
Lentiviral transduction of face and limb flaps: implications for immunomodulation of vascularized composite allografts.
2012
Background Ex vivo introduction of an immunomodulatory transgene into a face or hand allograft may improve the risk-to-benefit ratio of vascularized composite allografts. Abrogation of the immunogenicity of the skin component of a face or hand allograft may decrease alloreactivity and permit the induction of immunologic tolerance. Proof-of-principle demonstrations of transduction of composite tissue have been established using adenoviral vectors, producing transient gene expression. The authors hypothesized that transduction, integration, and long-term expression of transgenes in a vascularized composite allograft could be achieved using lentiviral vectors. Methods Ex vivo transduction of h…
Cutaneous Exposure to the Superantigen Staphylococcal Enterotoxin B Elicits a T-Cell-Dependent Inflammatory Response
1996
We analyzed the impact of superantigens secreted by skin-colonizing Staphylococci on the skin and the associated lymphoid tissue following epicutaneous application and intracutaneous injection of small amounts of staphylococcal enterotoxin B (SEB). A single intracutaneous injection of 50 ng of SEB elicited a strong inflammatory response in the skin of BALB/c mice. Three to 6 h later, we observed langerhans cell activation, mast cell degranulation, vasodilation, upregulation of ICAM-1, and induction of VCAM-1 on dermal blood vessels, with vascular adhesion of granulocytes. by 12 to 24 h, cell infiltration of the dermis increased, reaching the epidermis. Among the infiltrating leukocytes, a s…
Secondary hyperalgesia to punctate mechanical stimuli
1999
Tissue injury induces enhanced pain sensation to light touch and punctate stimuli in adjacent, uninjured skin (secondary hyperalgesia). Whereas hyperalgesia to light touch (allodynia) is mediated by A-fibre low-threshold mechanoreceptors, hyperalgesia to punctate stimuli may be mediated by A- or C-fibre nociceptors. To disclose the relative contributions of A- and C-fibres to the hyperalgesia to punctate stimuli, the superficial radial nerve was blocked by pressure at the wrist in nine healthy subjects. Secondary hyperalgesia was induced by intradermal injection of 40 microg capsaicin, and pain sensitivity in adjacent skin was tested with 200 micron diameter probes (35-407 mN). The progress…