Penetration studies of an extremely lipophilic active model substance from an oil-in-water emulsion: influence of the lipophilicity of the formulation in human skin - part 2.

The effect of the lipophilicity of a carrier on human skin penetration of an extremely lipophilic active model substance was evaluated by using Franz type diffusion cells. Oil-in-water model emulsions containing different amounts of the oily phase were prepared, and Myritol® PC (M-PC) was selected as lipophilic marker component of the oily phase. The penetrated amounts of the lipophilic model substance salicyloyl phytosphingosine (SP) were determined by high-performance liquid chromatography with ultraviolet detection, while M-PC was detected using gas chromatography coupled with mass spectrometry. It has been ascertained that the amount of the lipid phase within the emulsion influenced the penetration profile of the active ingredient SP. The emulsion containing the lowest proportion of the lipid phase provides the best conditions for SP penetration. Surprisingly, the penetration behavior of M-PC was influenced by the oily phase in the same way. Regarding the M-PC and the SP penetration profiles from each emulsion, a solvent drag mechanism can be assumed whereby M-PC acts as penetration enhancer. In conclusion, the penetration rate of the active ingredient SP and the marker component M-PC are in reverse proportion to the oil content of the formulations. The lipophilicity of SP and M-PC, their solubility and their thermodynamic activity within the vehicle could have an effect on their penetration behavior. Additionally, M-PC has the property to enhance the penetration rates of extremely lipophilic substances even at low concentrations.

Characteristics of pain and their relationship to disease activity in UK patients with Behçet's syndrome: a prospective cohort study.

Background: Behçet's syndrome (BS) is a rare multi-systemic vasculitis of unknown aetiology. Fibromyalgia syndrome (FMS) is more prevalent in rheumatological conditions such-as BS, than the general population. However, there is limited research into the aetiology and characteristics of pain in BS. Objectives: To describe the pain characteristics and incidence of FMS in people with BS and investigate their relationship with BS disease activity. Methods: A cohort study of BS patients attending the Liverpool Behçet's Centre between February 2017 and March 2019. BS was defined using the International Study Group Criteria. BS severity was assessed using the Behçet's Disease Current Activity Form. FMS was determined from consultant diagnosis. Assessments of pain included: Pain Visual Analogue Scale (PVAS), Pain Mannequin, Brief Pain Inventory, EQ-5D-3L and Short Form McGill. Pain and FMS prevalence were compared between high and low disease activity. Results: 90% reported moderate-severe pain with a median PVAS score of 68/100 [38, 81]. 35.6% of participants had FMS and 46.5% experienced generalized pain. 76% of participants with high disease activity reported severe pain, compared to 39.1% with low disease activity (p = .003). Pain was more generalised in high disease activity (72%) compared to low disease activity (37.7%) (p = .003). FMS was more prevalent in the high disease activity group (52%) than the low disease activity group (29%) (p = .04). Conclusions: This is the first study to explore pain in participants with BS in the United Kingdom. The majority of BS patients experience moderate-severe widespread pain. Severe widespread pain is more prevalent in those with high disease activity. We have demonstrated a relationship between high disease activity, worse pain intensity, and FMS. This paper contributes to the understanding of two conditions which remain to be fully understood, FMS and BS, and generates new hypotheses to describe the interplay between.

Dermal peptide delivery using enhancer molecules and colloidal carrier systems--part I: carnosine.

Due to the lipophilic properties of the uppermost skin layer of the stratum corneum (SC), it is highly challenging to attain therapeutic concentrations of active substances; hydrophilic drugs, in particular, penetrate poorly. The purpose of this study was the improvement of the topical bioavailability of the hydrophilic dipeptides L-carnosine and its related compound N-acetyl-L-carnosine. Different strategies were investigated. On the one hand, an enhancer molecule, 1,2-pentylene glycol (PG), was added to a standard preparation, and on the other hand, a microemulsion (ME-PG) system was developed. Both were compared to the standard formulation without an enhancer molecule. For all 3 preparations, the penetration of the peptides in ex vivo human skin was investigated. This allows statements to be made regarding dermal penetration, localization and distribution of the active substances in each skin layer as well as the influence of vehicle variations, in this case, the addition of PG or the incorporation of N-acetyl-L-carnosine in an ME-PG system. For L-carnosine and N-acetyl-L-carnosine, the use of the standard preparation with PG resulted in a significant increase of the substance within the SC. Approximately 6-fold and higher dipeptide concentrations in the SC and in the viable skin layers were detected at all experimental periods compared to the formulation without the enhancer molecule and the ME-PG. High concentrations of the compounds were found after a short period of time in the viable skin layers after applying the enhancer molecule, even in concentrations of 5%. The application of the colloidal carrier system did not lead to a higher penetration rate of N-acetyl-L-carnosine in comparison to both standard preparations, although it must be said that the microstructure of the investigated ME-PG might not have been optimal for the hydrophilic properties of the dipeptide.

Charge state switching of deep levels for low-power optical modulation in silicon waveguides.

We demonstrate a method for the efficient modulation of optical wavelengths around 1550 nm in silicon waveguides. The amplitude of a propagating signal is mediated via control of the charge state of indium centers, rather than using free-carriers alone as in the plasma-dispersion effect. A 1×1 switch formed of an integrated p-i-n junction in an indium-doped silicon on insulator (SOI) waveguide provides 'normally-off' silicon absorption of greater than 7 dB at zero bias. This loss is decreased to 2.8 dB with application of a 6 V applied reverse bias, with a power consumption of less than 1 µW.

Denying the Truth Does Not Change the Facts: A Systematic Analysis of Pseudoscientific Denial of Complex Regional Pain Syndrome.

PURPOSE: Several articles have claimed that complex regional pain syndrome (CRPS) does not exist. Although a minority view, it is important to understand the arguments presented in these articles. We conducted a systematic literature search to evaluate the methodological quality of articles that claim CRPS does not exist. We then examined and refuted the arguments supporting this claim using up-to-date scientific literature on CRPS. METHODS: A systematic search was conducted in MEDLINE, EMBASE and Cochrane CENTRAL databases. Inclusion criteria for articles were (a) a claim made that CRPS does not exist or that CRPS is not a distinct diagnostic entity and (b) support of these claims with subsequent argument(s). The methodological quality of articles was assessed if possible. RESULTS: Nine articles were included for analysis: 4 narrative reviews, 2 personal views, 1 letter, 1 editorial and 1 case report. Seven points of controversy were used in these articles to argue that CRPS does not exist: 1) disagreement with the label "CRPS"; 2) the "unclear" pathophysiology; 3) the validity of the diagnostic criteria; 4) CRPS as a normal consequence of immobilization; 5) the role of psychological factors; 6) other identifiable causes for CRPS symptoms; and 7) the methodological quality of CRPS research. CONCLUSION: The level of evidence for the claim that CRPS does not exist is very weak. Published accounts concluding that CRPS does not exist, in the absence of primary evidence to underpin them, can harm patients by encouraging dismissal of patients' signs and symptoms.

Optical modulation in silicon waveguides via charge state control of deep levels.

The control of defect mediated optical absorption at a wavelength of 1550 nm via charge state manipulation is demonstrated using optical absorption measurements of indium doped Silicon-On-Insulator (SOI) rib waveguides. These measurements introduce the potential for modulation of waveguide transmission by using the local depletion and injection of free-carriers to change deep-level occupancy. The extinction ratio and modulating speed are simulated for a proposed device structure. A 'normally-off' depletion modulator is described with an extinction coefficient limited to 5 dB/cm and switching speeds in excess of 1 GHz. For a carrier injection modulator a fourfold enhancement in extinction ratio is provided relative to free carrier absorption alone. This significant improvement in performance is achieved with negligible increase in driving power but slightly degraded switching speed.

Altered intestinal permeability in patients with primary fibromyalgia and in patients with complex regional pain syndrome.

OBJECTIVES: The pain intensity of patients with FM has recently been reported to be correlated with the degree of small intestinal bacterial overgrowth (SIBO). SIBO is often associated with an increased intestinal permeability (IP). Increased IP, if shown in FM, may have pathogenetic relevance because it leads to the exposure of immune cells to luminal antigens and consequent immune modulation. It is currently unknown whether IP is altered in FM. We therefore examined the IP in a group of patients with primary FM and in two control groups, healthy volunteers and patients with an unrelated chronic pain syndrome, complex regional pain syndrome (CRPS). We hypothesized that patients with FM, but not volunteers or those patients with CRPS, would have altered IP. METHODS: Both gastroduodenal and small IP were assessed using an established three-sugar test, where urinary disaccharide excretion reflecting intestinal uptake was measured using HPLC. RESULTS: Forty patients with primary FM, 57 age- and sex-matched volunteers and 17 patients with CRPS were enrolled in this study. In the FM group, 13 patients had raised gastroduodenal permeability and 15 patients had raised small intestinal permeability, but only one volunteer had increased gastroduodenal permeability (P < 0.0001, chi-square test for the three groups). The IP values were significantly increased in the patient groups (P < 0.0003 for all comparisons, one-way analysis of variance). CONCLUSIONS: The IPs in primary FM and, unexpectedly, CRPS are increased. This study should stimulate further research to determine the implication of altered IP in the disease pathophysiology of FM and CRPS.

Are you better? A multi-centre study of patient-defined recovery from Complex Regional Pain Syndrome.

BACKGROUND: Complex Regional Pain Syndrome (CRPS) symptoms can significantly differ between patients, fluctuate over time, disappear or persist. This leads to problems in defining recovery and in evaluating the efficacy of therapeutic interventions. OBJECTIVES: To define recovery from the patients' perspective and better understand their priorities for treatment approaches. METHODS: Establishing an international consortium, we used a 2-Round Delphi-based study in eight countries across Europe and North America. Participants ≥18 years who met, or had met, Budapest clinical criteria were included. Round 1 participants completed the statement: 'I would/do consider myself recovered from CRPS if/because…' alongside demographic and health questionnaires. Data were thematically organised and represented as 62 statements, from which participants identified and ranked their recovery priorities in Round 2. RESULTS: Round 1 (N = 347, 80% female, 91% non-recovered) dominant ICF themes were: activities of daily living; bodily functions; external factors; participation and personal factors. The top five priority statements in Round 2 (N = 252) were: no longer having (1) CRPS-related pain, (2) generalised pain and discomfort, (3) restricted range of movement, (4) need for medication, (5) stiffness in the affected limb. With very few exceptions, priorities were consistent, irrespective of patient demographics/geography. Symptoms affecting daily activities were among those most frequently reported. CONCLUSIONS: Our data showed a small number of themes are of highest importance to CRPS patients' definition of recovery. Patients want their pain, movement restriction and reliance on medication to be addressed, above all other factors. These factors should therefore be foremost concerns for future treatment and rehabilitation programmes. SIGNIFICANCE: Those with longstanding CRPS may no longer meet diagnostic criteria but still be symptomatic. Defining recovery is therefore problematic in CRPS. Our study has identified patients' definition of recovery from CRPS, in order of priority, as relief from: their CRPS-related pain, generalised pain, movement restriction, reliance on medication, and stiffness.

Cutaneous immunopathology of long-standing complex regional pain syndrome.

BACKGROUND: Both increased mast cells numbers and raised immune mediator concentrations indicate immune activation in the affected skin of patients with early complex regional pain syndrome (CRPS), but little is known about regional immune cell involvement in late-stage CRPS. The aim of the current study was to determine skin immune cell populations in long-standing CRPS. METHODS: Using 6-mm skin punch biopsies from CRPS-affected and non-affected tissues, and a combination of chemical and immunofluorescence staining, we examined the density and function of key cell populations including mast cells, epidermal Langerhans cells (LCs) and tissue resident T-cells. RESULTS: We found no significant differences in either overall immune cell infiltrates, or mast cell density between CRPS-affected and non-affected sub-epidermal tissue sections, contrasting recent findings in early CRPS by other groups. However, CD1a(+) LC densities in the epidermal layer were significantly decreased in affected compared to non-affected CRPS limbs (p < 0.01). T-cell clones isolated from CRPS-affected sub-epidermal tissues displayed a trend towards increased IL-13 production in ELISPOT assays when compared to T-cells isolated from non-affected areas, suggesting a Th2 bias. CONCLUSIONS: Immune cell abnormalities are maintained in late-stage CRPS disease as manifest by changes in epidermal LC density and tissue resident T-cell phenotype.

Injury primes the immune system for an enhanced and lethal T-cell response against bacterial superantigen.

We previously reported the high lethality of CD4+ T-cell activation in burn-injured T-cell receptor (TCR) transgenic mice. This suggested to us that T-cells may play a role in the development of the systemic inflammatory response syndrome (SIRS) which can occur after severe injury. In this study, we sought a more clinically relevant model to test the hypothesis that naturally produced bacterial toxins that are known to act as potent polyclonal T-cell activating agents may induce a similar lethal shock-like response in injured, non-TCR transgenic mice. Accordingly, sham- or burn-injured mice were treated with various doses of staphylococcal enterotoxin A (SEA), then observed for 48-hour mortality. We observed 94% and 56% 48-h mortality when burn-injured mice were given 15 microg and 10 microg of SEA, respectively, while neither SEA dose caused mortality in sham-injured mice. The assessment of serum cytokine levels demonstrated significantly elevated interleukin 2 (IL-2) and tumor necrosis factor alpha (TNFalpha) levels when compared to sham mice (P < 0.01). In vitro studies confirmed our in vivo results and also demonstrated elevated levels of interferon gamma (IFNgamma) (P < 0.01). We also observed a novel injury-dependent switch from CD4+ to CD8+ T-cells as the dominant T-cell type producing TNFalpha and IFNgamma in response to SEA stimulation in vitro. Taken together, our findings indicate that injury primes the immune system for an augmented early T-cell response that can result in a lethal shock-like syndrome.

Interleukin 10 is not essential for survival or for modulating T-cell function after injury.

BACKGROUND: Interleukin 10 (IL-10) is thought to be protective in injury and sepsis. However, we recently reported that IL-10 antagonism can be beneficial after burn injury. This study used IL-10-deficient (IL-10 [-/-]) mice to further define the role of IL-10 after injury. METHODS: Wild-type (WT) C57BL/6 or IL-10 (-/-) mice were anesthetized, sham or burn injured, and immunized subcutaneously with a T-cell-dependent protein antigen. Ten days later antigen-specific serum antibody isotype formation was measured by enzyme-linked immunosorbent assay. In addition, antigen-stimulated splenic T-cell proliferation and cytokine production (interleukin 2, interferon gamma, and tumor necrosis factor-alpha) were measured. RESULTS: Burn-injured IL-10 (-/-) mice survival (80%) was equivalent to that of burn-injured WT mice (74%). An injury-dependent loss of T-helper 1 (Th1)-type antibody isotype (IgG2a) formation occurred in both WT and IL-10 (-/-) mice. In vitro studies indicated that burn injury caused reduced antigen-stimulated splenic T-cell proliferation and Th1-type (interleukin 2 and interferon gamma) cytokine production in WT and IL-10 (-/-) mice, whereas burn-injured IL-10 (-/-) mice produced high levels of antigen-stimulated tumor necrosis factor-alpha. CONCLUSIONS: IL-10 is not essential for survival after burn injury or for several injury-induced changes in adaptive immune function, including Th1-type antibody isotype formation, T-cell proliferation, and Th1-type cytokine production.

Protective effects of early interleukin 10 antagonism on injury-induced immune dysfunction.

HYPOTHESIS: Interleukin 10 (IL-10) plays a central role in the development of postinjury immune suppression, and early in vivo IL-10 antagonism can be protective. DESIGN: Male A/J mice underwent sham or burn injury and were treated with monoclonal anti-IL-10 antibody or control antibody at 1 day or 3 days after injury. Their ability to survive polymicrobial sepsis induced by the cecum ligation and puncture (CLP) technique was then tested. The response of sham- and burn-injured mice and burn-injured mice treated with anti-IL-10 to immunization with a T-cell-dependent antigen, trinitrophenyl (TNP)-haptenated ovalbumin (TNP-OVA) was also assessed. MAIN OUTCOME MEASURES: Mortality was monitored for a total of 7 days after CLP to assess the effect of anti-IL-10 therapy on the survival of burn-injured, immunecompromised mice. Serum antibody isotype formation was measured in sham- and burn-injured mice and burn-injured mice treated with anti-IL-10 to determine how IL-10 antagonism influenced helper T-cell responses in vivo. In vitro cytokine production by antigen-stimulated spleen cells was assessed to study the effect of blocking IL-10 activity at 1 day vs 3 days after burn injury. RESULTS: Treating mice with anti-IL-10 at 1 day after injury significantly improved CLP survival, whereas delaying treatment 3 days had no beneficial effect. The analysis of T-cell function in vivo as determined by serum antibody isotype formation indicated that anti-IL-10 treatment at 1 day or 3 days after injury increased T helper cell 1-type antibody formation to sham injury levels by day 10. Moreover, these treatments restored the injury-induced reduction of antigen-stimulated IL-2, interferon gamma, and IL-10 production. CONCLUSIONS: Interleukin 10 plays an early role in the development of burn injury-induced immune suppression. Its in vivo inhibition at 1 day after injury may be a useful approach toward preventing the development of injury-induced immune dysfunction and may do so by restoring T-cell function and cytokine production.

[Emission of air pollutants in removal of bone cement with ultrasound instruments in revision endoprosthetics]. / Schadstoffemissionen bei der Entfernung von Knochenzement mit Ultraschallgeräten in der Revisionsendoprothetik.

The use of ultrasonic instruments to remove PMMA bone cement during revision hip arthroplasty results in the production of fumes. These emissions were analysed under standardized laboratory conditions, when it was found that the MMA concentration measured was only 1/10th of the MAC value. In terms of occupational safety, the MMA fumes emitted may therefore be considered non-hazardous for the medical personnel.

[Rapid preliminary diagnosis of anaerobic bacterial infections. II. Investigation of the presence of volatile and non-volatile fatty acids (C1-C6) in pus, purulent fluids and dressing by application of gas chromatography]. / Szybka wstepna diagnostyka zakazen bakteriami beztlenowymi. II. Badanie obecnosci lotnych i nielotnych kwasów tluszczowych (C1-C6) w ropie, plynach ropnych i opatrunkach przy zastosowaniu chromatografii gazowej.

Studies were performed in the years 1986-1990 and dealing with 405 clinical materials originating from infections within the abdominal cavity, maxilla, reproductive organ, post-operative wounds as well as dressings, extremities, blood, bile and other types of material and usefulness of analysis by gas chromatography of presence of lower fatty acids in materials for rapid and preliminary diagnostics with strictly anaerobic bacteria was confirmed. Presence in chromatograms of isobutyric, butyric isovaleric, valeric, isocaproic and caproic acid, and partly of propionic acid, is a good indication of infection with strictly anaerobic bacteria. Moreover, presence of succinic acid may suggest presence of anaerobic infection, similarly as presence in chromatograms of three or more various lower fatty acids. Rapid, approximative diagnosis of anaerobic bacteria by application of gas chromatography is worth of broader application. Investigation of clinical material by this method lasts only 1-2 hours and obtained results my present a basis for preliminary diagnosis of the etiological factor and for direction of chemotherapy, which is very important in most early period of treatment of infections.

Treatment of complex regional pain syndrome in adults: a systematic review of randomized controlled trials published from June 2000 to February 2012.

Complex regional pain syndrome (CRPS) is a disabling pain condition with sensory, motor and autonomic manifestations. Uncertainty remains about how CRPS can be effectively managed. We conducted a systematic review of randomized controlled trials (RCTs) for treatment and prophylactic interventions for CRPS published during the period 2000-2012, building on previous work by another group reviewing the period 1966-2000. Bibliographic database searches identified 173 papers which were filtered by three reviewers. This process generated 29 trials suitable for further analysis, each of which was reviewed and scored by two independent reviewers for methodological quality using a 15-item checklist. A number of novel and potentially effective treatments were investigated. Analysing the results from both review periods in combination, there was a steep rise in the number of published RCTs per review decade. There is evidence for the efficacy of 10 treatments (3× strong--bisphosphonates, repetitive transcranial magnetic stimulation and graded motor imagery, 1× moderate and 6× limited evidence), and against the efficacy of 15 treatments (1× strong, 1× moderate and ×13 limited). The heterogeneity of trialled interventions and the pilot nature of many trials militate against drawing clear conclusions about the clinical usefulness of most interventions. This and the observed phenomenon of excellent responses in CRPS subgroups would support the case for a network- and multi-centre approach in the conduct of future clinical trials. Most published trials in CRPS are small with a short follow-up period, although several novel interventions investigated from 2000 to 2012 appear promising.

Using graded motor imagery for complex regional pain syndrome in clinical practice: failure to improve pain.

BACKGROUND: There is good evidence from studies conducted in a single-centre research setting for the efficacy of graded motor imagery (GMI) treatment, a complex physiotherapy intervention, to reduce pain in long-standing complex regional pain syndrome (CRPS). However, whether GMI is effective in clinical practice is not established. AIM: To establish whether GMI is effective in clinical practice. METHODS: We undertook a prospective audit of GMI treatment at two UK centres with a special interest in the management of patients with CRPS. All patients received GMI, in conjunction with a range of other 'best practice' physical and psychological interventions. RESULTS: The patients' average pain intensities did not improve with treatment [centre 1: n = 20, pre-post numeric rating scale (NRS) difference 0.6 [confidence interval (CI) -0.3 to 1.5]; centre 2: n = 12, pre-post NRS difference 0.2 (CI: -0.9 to 1.2)]. Patients at centre 1 reported significant functional improvement. Improved performance on left/right judgement replicated in both centres seen in the clinical trials. CONCLUSIONS: The failure of our real-world implementation of GMI suggests that better understanding of both the GMI methodology and its interaction with other treatment methods is required to ensure that GMI research results can be translated into clinical practice. Our results highlight challenges with the translation of complex interventions for chronic pain conditions into clinical practice.

LIM-kinase 2, a regulator of actin dynamics, is involved in mitotic spindle integrity and sensitivity to microtubule-destabilizing drugs.

LIM-kinase 2 (LIMK2) belongs to the LIMK family of proteins, which comprises LIMK1 and LIMK2. Both proteins regulate actin polymerization through phosphorylation and inactivation of the actin depolymerizing factor cofilin. In this study, we show that the level of LIMK2 protein is increased in neuroblastoma, BE(2)-C cells, selected for resistance to microtubule-destabilizing agents, vincristine and colchicine. However, the level of phosphorylated LIMK1 and LIMK2 was similar in the resistant and parental BE(2)-C cells. In contrast, the level of phospho-cofilin was greatly increased in the drug-resistant cells. Downregulation of LIMK2 expression increases sensitivity of neuroblastoma SH-EP cells to vincristine and vinblastine but not to microtubule-stabilizing agents, while it's overexpression increased its resistance to vincristine. Its vincristine-induced mitotic arrest was moderately inhibited in the LIMK2 knockdown cells, suggesting that the increased drug sensitivity is through an alternative mechanism other then mitotic arrest and apoptosis. Moreover, downregulation of LIMK2 expression induces formation of abnormal mitotic spindles, an effect enhanced in the presence of microtubule-destabilizing agents. LIMK2 is important for normal mitotic spindle formation and altered LIMK2 expression mediates sensitivity to microtubule destabilizing agents. These findings suggest that inhibition of LIMK2 activity may be used for the treatment of tumors resistant to microtubule-destabilizing drugs.