Modulation of the release and activity of neuropeptides in the microcirculation

Influence of Internal Organ Pathology on Vascular Permeability of Related Skin Zones: An Attempt to Visualize Organ Projection Areas

Objective: Pathology of an internal organ/body part changes electrical features of the corresponding skin areas-organ projection areas (OPAs)-which are often identified with traditional acupuncture points/zones. Once the resistance "breakthrough effect" has been induced in these specific skin areas, rectification of applied electrical currents (a diode phenomenon) occurs. In addition, increased impedance can be observed. It is presumed that these skin bioelectrical phenomena are the result of increased local capillary permeability with extravasation of blood-plasma albumins. Contrast-enhanced magnetic resonance imaging (MRI) of the microvasculature, using labeled albumins as markers, allows visualization of skin areas with higher albumin concentrations. The goal of this research was experimental verification of the abovementioned physiologic hypothesis by visualization of the OPAs. Materials and Methods: Preselected, comparative, contrast-enhanced magnetic resonance imaging (MRI) studies of the auricular microvasculature were performed in the Division of Diagnostic Radiology of Charlotte Maxeke Academic Hospital in Johannesburg, South Africa, in a group of 42 volunteers with proven clinical conditions of 49 (in total) chosen internal organs/body parts. Previously, 28 auricular OPAs related to internal organs/body parts with proven pathologies showed the abovementioned bioelectrical phenomena and 21 auricular OPAs in a control group did not show those phenomena to a significant extent. Contrast-enhanced MRI assessment of the study participants' ear auricle vascular permeability was performed after 1, 2, 3, 4, and 5 minutes after a standard contrast, which binds to albumins transiently, was injected intravenously. Contrast-enhanced magnetic resonance images of the diseased body part-related OPAs versus images of the same but healthy body part-related OPAs (control group) were subjected to a final statistical comparison. Results: It was presumed that 24 OPAs related to internal organs/body parts with serious pathologies were visualized by means of labeled albumins and 25 OPAs corresponding to healthy body parts or minor pathologies were not seen. OPA visibility depended on the extent of pathology within the related internal organ/body part, but not on the kind of organ/body part nor etiology or kind of disease. Conclusions: Pathology of internal organ/body parts appears to cause higher concentrations of albumins within related OPAs and, in this way, creates specific electrical phenomena observed at the OPAs. Contrast-enhanced MRI of the microvasculature, using labeled albumins, can be useful for visualizing OPAs.

Enterococcus faecalis overcomes foreign body-mediated inflammation to establish urinary tract infections

Urinary catheterization elicits major histological and immunological changes that render the bladder susceptible to microbial invasion, colonization, and dissemination. However, it is not understood how catheters induce these changes, how these changes act to promote infection, or whether they may have any protective benefit. In the present study, we examined how catheter-associated inflammation impacts infection by Enterococcus faecalis, a leading cause of catheter-associated urinary tract infection (CAUTI), a source of significant societal and clinical challenges. Using a recently optimized murine model of foreign body-associated UTI, we found that the implanted catheter itself was the primary inducer of inflammation. In the absence of the silicone tubing implant, E. faecalis induced only minimal inflammation and was rapidly cleared from the bladder. The catheter-induced inflammation was only minimally altered by subsequent enterococcal infection and was not suppressed by inhibitors of the neurogenic pathway and only partially by dexamethasone. Despite the robust inflammatory response induced by urinary implantation, E. faecalis produced biofilm and high bladder titers in these animals. Induction of inflammation in the absence of an implanted catheter failed to promote infection, suggesting that the presence of the catheter itself is essential for E. faecalis persistence in the bladder. Immunosuppression prior to urinary catheterization enhanced E. faecalis colonization, suggesting that implant-mediated inflammation contributes to the control of enterococcal infection. Thus, this study underscores the need for novel strategies against CAUTIs that seek to reduce the deleterious effects of implant-mediated inflammation on bladder homeostasis while maintaining an active immune response that effectively limits bacterial invaders.

Use of acupuncture as a treatment method for chronic prostatitis/chronic pelvic pain syndromes

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is the most common category of clinical prostatitis. The etiologic factors of CP/CPPS still remain unknown, and standard therapies often fail to achieve sustainable amelioration of symptoms; therefore, various treatment therapies have been approached. Recently, there is increasing evidence that acupuncture could be a safe and effective treatment in managing CP/CPPS. However, acupuncture therapy still is ranked as low-priority treatment, which results from the fact that the studies, mostly reported in nontraditional medical journals, had not employed standard definitions of the condition or validated-outcome parameters, and that the mechanism of acupuncture effects on CP/CPPS remains to be elucidated. In this article, we review the recent clinical research using acupuncture to reveal its clinical utility for CP/CPPS and the possible mechanisms of action. This article could encourage health care providers and urologists to apply acupuncture for managing pains of CP/CPPS with standard treatment.

Treatment of plantar fasciitis in recreational athletes: two different therapeutic protocols

Plantar fasciitis (PF) commonly causes inferior heel pain and occurs in up to 10% of the US population. Treatment protocols in most studies include the use of ice therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and stretching and strengthening protocols. The aim of the current study was to examine the effectiveness of 2 different therapeutic approaches on the treatment of PF in recreational athletes using the Pain and Disability Scale for the evaluation. A total of 38 participants with PF were randomly allocated to 2 different groups of 19 male participants in each group. Group 1 was treated with ice, non-steroidal anti-inflammatory medication, and a stretching and a strengthening program. Group 2 received the same therapeutic procedures as group 1, reinforced by acupuncture treatment. The primary outcomes, nominated a priori, were pain description and mobility-function at 1 and 2 months. Outcomes were measured with the pain scale for PF. The mean total score of the acupuncture group at the third measurement was statistically minor compared with the mean total score of the first group. Acupuncture should be considered as a major therapeutic instrument for the decrease of heel pain, combined with traditional medical approaches.

Role of the transient receptor potential vanilloid 1 in inflammation and sepsis

The transient receptor potential vanilloid 1 (TRPV1) is a thermoreceptor that responds to noxious temperatures, as well as to chemical agonists, such as vanilloids and protons. In addition, its channel activity is notably potentiated by proinflammatory mediators released upon tissue damage. The TRPV1 contribution to sensory neuron sensitization by proalgesic agents has signaled this receptor as a prime target for analgesic and anti-inflammatory drug intervention. However, TRPV1 antagonists have notably failed in clinical and preclinical studies because of their unwanted side effects. Recent reports have unveiled previously unrecognized anti-inflammatory and protective functions of TRPV1 in several diseases. For instance, this channel has been suggested to play an anti-inflammatory role in sepsis. Therefore, the use of potent TRPV1 antagonists as a general strategy to treat inflammation must be cautiously considered, given the deleterious effects that may arise from inhibiting the population of channels that have a protective function. The use of TRPV1 antagonists may be limited to treating those pathologies where enhanced receptor activity contributes to the inflamed state. Alternatively, therapeutic paradigms, such as reduction of inflammatory-mediated increase of receptor expression in the cell surface, may be a better strategy to prevent abrogation of the TRPV1 subpopulation involved in anti-inflammatory and protective processes.

Peptide-mediated transdermal delivery of botulinum neurotoxin type A reduces neurogenic inflammation in the skin

Release of inflammatory pain mediators from peripheral sensory afferent endings contributes to the development of a positive feedback cycle resulting in chronic inflammation and pain. Botulinum neurotoxin type A (BoNT-A) blocks exocytosis of neurotransmitters and may therefore block the release of pain modulators in the periphery. Subcutaneous administration of BoNT-A (2.5, 5 and 10U) reduced plasma extravasation (PE) caused by electrical stimulation of the saphenous nerve or capsaicin in the rat hindpaw skin (ANOVA, Post hoc Tukey, p<0.05, n=6). Subcutaneous BoNT-A also reduced blood flow changes evoked by saphenous nerve stimulation (ANOVA, Post hoc Tukey, p<0.05, n=6). Subcutaneous BoNT-A had no effect on PE induced by local injection of substance P (SP) or vasodilation induced by local CGRP injection. Although BoNT-A is an effective treatment for a wide range of painful conditions, the toxin's large size necessitates that it be injected at numerous sites. We found that a short synthetic peptide (TD-1) can facilitate effective transdermal delivery of BoNT-A through intact skin. Coadministration of TD-1 and BoNT-A to the hindpaw skin resulted in a significant reduction in PE evoked by electrical stimulation. The findings show that BoNT-A can be administered subcutaneously or topically with a novel transdermal delivery peptide to reduce inflammation produced by activating nociceptors in the skin. Peptide-mediated delivery of BoNT-A is an easy and non-invasive way of administering the toxin that may prove to be useful in clinical practice.

Sex differences in inflammation evoked by noxious chemical, heat and electrical stimulation

Neurogenic inflammation (NI) is a feature of several inflammatory pain conditions in which females are overrepresented. Therefore, we asked if there are sex differences in the inflammatory response evoked by well known neurogenic stimuli. We compared the amount of plasma extravasation (PE), a measure of inflammation, in the hindpaw skin of male and female rats caused by subcutaneous injection of capsaicin, application of noxious heat (51 degrees C water bath) or electrical stimulation of the saphenous nerve. We also compared the amount of PE in males and females evoked by substance P (SP), the principal neurogenic mediator of PE. PE was quantified using a video camera and digital image analysis to measure changes in reflectance (pixel intensity, PI) of skin due to accumulation of extravasated Evans blue (EB) dye. The increase in PI induced by capsaicin was significantly greater in females compared to males (p<0.001) and in estrus, diestrus, and metestrus females compared to proestrus females. The time to reach maximal capsaicin-induced PE was two times longer in estrus, diestrus, and metestrus females compared to males (p<0.05). PE induced by heat was also significantly greater in females compared to males (p<0.001), however, there was no sex-related difference in PE induced by electrical stimulation or by injection of SP. These findings show that females have a greater inflammatory response when inflammation is induced by capsaicin and noxious heat suggesting possible sex-related changes in TRPV-1 receptor mediated mechanisms. These results add to the growing list of sex difference responses to noxious somatic stimulation.

Effectiveness of acupuncture, special dressings and simple, low-adherence dressings for healing venous leg ulcers in primary healthcare: study protocol for a cluster-randomized open-labeled trial

Background

Venous leg ulcers constitute a chronic recurring complaint that affects 1.0–1.3% of the adult population at some time in life, and which corresponds to approximately 75% of all chronic ulcers of the leg. Multilayer compression bandaging is, at present, the only treatment that has been proved to be effective in treating this type of ulcer. There is no consensus, however, about the dressings that may be applied, beneath the compression, to promote the healing of this type of ulcer, as there does not seem to be any added benefit from using special dressings rather than simple, low-adherence ones. As well as analgesia, acupuncture provokes peripheral vasodilation, in skin and muscles – which has been demonstrated both experimentally and in clinical practice – probably due to the axon reflex, among other mechanisms. The aim of the present study is to measure the effectiveness and cost of compression treatment for venous leg ulcers combined with special dressings, in comparison with low-adherence ones and acupuncture.

Methods/design

Cluster-randomized open-labeled trial, at 15 primary healthcare clinics in the Sevilla-Sur Healthcare District, with a control group treated with compression bandaging and low-adherence dressings; the experiment will consist, on the one hand, of the compression treatment applied in combination with special dressings (Treatment 1), and on the other, the compression treatment applied in association with low-adherence dressings, together with acupuncture (Treatment 2).

Discussion

The results will be measured and recorded in terms of the median time elapsed until complete healing of the ulcer, and the rate of complete healing at 3 months after beginning the treatment. An economic analysis will also be made.

This study, carried out in the context of real clinical practice, will provide information for decision-taking concerning the effectiveness of special dressings. Moreover, for the first time a high-quality study will evaluate the effectiveness of acupuncture in the process of healing venous leg ulcers.

Trial registration

Current Controlled Trials ISRCTN26438275.

Evaluation of the Time Course of Plasma Extravasation in the Skin by Digital Image Analysis

Plasma extravasation (PE) can be triggered by neurotransmitters as part of a neuroinflammatory response. We present a technique based on video digital image processing that provides a simple, noninvasive, reliable, and quantitative method for measuring the time course and extent of PE in the skin. After intravenous infusion of Evans Blue dye, stimulation of the saphenous nerve caused the skin on the dorsomedial region of the hind paw to become dark blue. The change in reflectance of the skin was recorded with a monochrome video camera. Images were digitized and analyzed with inexpensive or public domain software. The change in pixel intensity was determined in a selected region. Stimulation at 4 Hz caused greater darkening of the skin than at 1 Hz, and this was confirmed with spectrophotometric measurements of Evans Blue content. The NK1 receptor antagonist CP-99, 994 blocked saphenous nerve and substance P-induced darkening of the skin. The results indicate that our measurement gives results similar to those obtained with classic methods that are widely accepted as an indication of PE. This simple and quick method reveals the extent, time course, and location of PE, is cheap to implement and easy to learn, and thus represents a useful and alternative tool for studies of PE and its modulation.

PERSPECTIVE

This article presents a simple technique with which to evaluate the time course and extent of plasma extravasation in the skin of animal models of neuroinflammation. The technique is well suited to answer questions about basic physiologic mechanisms of neuroinflammation and should also be useful in drug testing studies.

Neurokinin 1-receptors and sensory neuropeptides in tendon insertions at the medial and lateral epicondyles of the humerus. Studies on tennis elbow and medial epicondylalgia

There is no information on the sensory innervation at the flexor muscle origin at the medial epicondyle of the humerus and it is not known if substance P receptors (Neurokinin 1-receptors, NK1-R) are present in tendon insertions in general. In the present investigation, we have studied the muscle origin in patients suffering from medial epicondylalgia and tennis elbow. Immunohistochemistry and antibodies to substance P (SP) and CGRP as well as the general nerve marker PGP 9.5 were used. Specific immunoreactions were observed in nerve bundles and as free nerve fibers. The immunoreactive structures were partly seen in association with some of the blood vessels. The observations constitute a morphological correlate for the occurrence of nerve mediated effects in this region. By using immunohistochemistry and antibodies to NK1-R, the distribution of this receptor was studied at the insertion of the proximal tendon of the extensor carpi radialis brevis muscle at the lateral epicondyle. Specific immunoreactions were seen as varicose fibers occurring as single fibers or grouped into bundles, indicating that SP has effects in the nerves in this region. The results give further evidence for a possible neurogenic involvement in the pathophysiology of tennis elbow and in medial epicondylalgia.

Anti-inflammatory actions of acupuncture

Acupuncture has a beneficial effect when treating many diseases and painful conditions, and therefore is thought to be useful as a complementary therapy or to replace generally accepted pharmacological intervention. The attributive effect of acupuncture has been investigated in inflammatory diseases, including asthma, rhinitis, inflammatory bowel disease, rheumatoid arthritis, epicondylitis, complex regional pain syndrome type 1 and vasculitis. Large randomised trials demonstrating the immediate and sustained effect of acupuncture are missing. Mechanisms underlying the ascribed immunosuppressive actions of acupuncture are reviewed in this communication. The acupuncture-controlled release of neuropeptides from nerve endings and subsequent vasodilative and anti-inflammatory effects through calcitonine gene-related peptide is hypothesised. The complex interactions with substance P, the analgesic contribution of beta-endorphin and the balance between cell-specific pro-inflammatory and anti-inflammatory cytokines tumour necrosis factor-alpha and interleukin-10 are discussed.

Stress and the inflammatory response: a review of neurogenic inflammation

The subject of neuroinflammation is reviewed. In response to psychological stress or certain physical stressors, an inflammatory process may occur by release of neuropeptides, especially Substance P (SP), or other inflammatory mediators, from sensory nerves and the activation of mast cells or other inflammatory cells. Central neuropeptides, particularly corticosteroid releasing factor (CRF), and perhaps SP as well, initiate a systemic stress response by activation of neuroendocrinological pathways such as the sympathetic nervous system, hypothalamic pituitary axis, and the renin angiotensin system, with the release of the stress hormones (i.e., catecholamines, corticosteroids, growth hormone, glucagons, and renin). These, together with cytokines induced by stress, initiate the acute phase response (APR) and the induction of acute phase proteins, essential mediators of inflammation. Central nervous system norepinephrine may also induce the APR perhaps by macrophage activation and cytokine release. The increase in lipids with stress may also be a factor in macrophage activation, as may lipopolysaccharide which, I postulate, induces cytokines from hepatic Kupffer cells, subsequent to an enhanced absorption from the gastrointestinal tract during psychologic stress. The brain may initiate or inhibit the inflammatory process. The inflammatory response is contained within the psychological stress response which evolved later. Moreover, the same neuropeptides (i.e., CRF and possibly SP as well) mediate both stress and inflammation. Cytokines evoked by either a stress or inflammatory response may utilize similar somatosensory pathways to signal the brain. Other instances whereby stress may induce inflammatory changes are reviewed. I postulate that repeated episodes of acute or chronic psychogenic stress may produce chronic inflammatory changes which may result in atherosclerosis in the arteries or chronic inflammatory changes in other organs as well.

Expression of neuropeptides and cytokines at the extensor carpi radialis brevis muscle origin

To reveal whether neuropeptides and cytokines affect the pathogenesis of tennis elbow, expressions of substance P, calcitonin gene-related peptide, interleukin 1 alpha, and transforming growth factor beta1 at the origin of the extensor carpi radialis brevis muscle were investigated in patients with tennis elbow (n = 10). Innervation in the origin was determined with use of the protein gene product 9.5. Substance P-like immunoreactivity and calcitonin gene-related peptide-like immunoreactivity were observed in the nerve fibers around small vessels without apparent infiltration of inflammatory cells. Cells showing positive interleukin 1 alpha or transforming growth factor beta1 immunoreactivity were noted in small vessels and the dense collagen meshwork in 5 of 10 cases. The results suggested that these neuropeptides and cytokines might promote inflammation and stimulate proliferation and matrix synthesis of fibroblasts, contributing to the pathology of tennis elbow.

Acupuncture mechanisms for clinically relevant long-term effects--reconsideration and a hypothesis

From the author's direct involvement in clinical research, the conclusion has been drawn that clinically relevant long-term pain relieving effects of acupuncture (>6 months) can be seen in a proportion of patients with nociceptive pain. The mechanisms behind such effects are considered in this paper. From the existing experimental data some important conclusions can be drawn: 1. Much of the animal research only represents short-term hypoalgesia probably induced by the mechanisms behind stress-induced analgesia (SIA) and the activation of diffuse noxious inhibitory control (DNIC). 2. Almost all experimental acupuncture research has been performed with electro-acupuncture (EA) even though therapeutic acupuncture is mostly gentle manual acupuncture (MA). 3. Most of the experimental human acupuncture pain threshold (PT) research shows only fast and very short-term hypoalgesia, and, importantly, PT elevation in humans does not predict the clinical outcome. 4. The effects of acupuncture may be divided into two main components--acupuncture analgesia and therapeutic acupuncture. A hypothesis on the mechanisms of therapeutic acupuncture will include: 1. Peripheral events that might improve tissue healing and give rise to local pain relief through axon reflexes, the release of neuropeptides with trophic effects, dichotomising nerve fibres and local endorphins. 2. Spinal mechanisms, for example, gate-control, long-term depression, propriospinal inhibition and the balance between long-term depression and long-term potentiation. 3. Supraspinal mechanisms through the descending pain inhibitory system, DNIC, the sympathetic nervous system and the HPA-axis. Is oxytocin also involved in the long-term effects? 4. Cortical, psychological, "placebo" mechanisms from counselling, reassurance and anxiety reduction.

Substance P and calcitonin gene-related peptide expression at the extensor carpi radialis brevis muscle origin: implications for the etiology of tennis elbow

With use of immunohistochemistry and antibodies to substance P and calcitonin gene-related peptide, nerve fibers showing substance P-like and calcitonin gene-related peptide-like immunoreactivity were demonstrated at the origin of the extensor carpi radialis brevis muscle in patients with tennis elbow (n = 6) and in healthy controls (n = 6). The nerve fibers were distributed in association with a subpopulation of small blood vessels and in nerve bundles but were not distributed in the tunica media-adventitia junction of the arterioles. There were no inflammatory-cell infiltrates and few solitary mast cells. The present study gives further evidence to previous suggestions that tennis elbow is not an inflammatory process in the sense of involving inflammatory cells. Frequent mechanical involvement affects sensory innervation, and substance P and calcitonin gene-related peptide may have various important efferent effects, including microvascular leakage and local edema formation; therefore, the observations from this study constitute a morphological substrate for possible effects of substance P and calcitonin gene-related peptide at the origin of the extensor carpi radialis brevis muscle.