Diagnostic criteria in patients with complex regional pain syndrome assessed in an out-patient clinic.

BACKGROUND: Specific criteria have been described and accepted worldwide for diagnosing patients with complex regional pain syndrome (CRPS). Nevertheless, a clear-cut diagnosis cannot be confirmed in a number of cases. AIM: The objective of this study was to investigate the effectiveness of the described diagnostic criteria used by several clinical disciplines. METHODS: We included 195 patients who were referred to our pain clinic within a period of 1 year. Data were collected on patient characteristics, signs, symptoms, disease-related medication, and the background of the referring clinicians. RESULTS: The Harden and Bruehl criteria were confirmed in 95 patients (49%). These patients used a higher than average number of analgesics, opiates, and anti-oxidants, and frequently received prescriptions for benzodiazepines instead of anti-depressants. The mean disease duration was 29 +/- 4.6 months and the mean visual analogue score for pain was 8.1 +/- 0.19. A subgroup of patients had a colder temperature in the affected extremity compared with the unaffected extremity. This subgroup showed a longer disease duration and higher visual analogue scale pain. CONCLUSION: The diagnostic criteria used to determine CRPS should be further improved. A large number of referred patients experienced substantial pain, without receiving adequate medication. Disease-related medication is unrelated to CRPS-specific disease activity. Knowledge of underlying mechanisms is warranted before an adequate pharmaceutical intervention can be considered.

Increased plasma glutamate, glycine, and arginine levels in complex regional pain syndrome type 1.

BACKGROUND: Various inflammatory mediators have been identified as potential contributors to complex regional pain syndrome type 1 (CRPS1), but these mediators do not entirely explain certain manifestations of the syndrome, such as pain. The objective of this study was to investigate the role of amino acids in the pathogenesis of CRPS1. METHODS: We used HPLC to determine plasma concentrations of 16 amino acids, especially those related to the NMDA receptor (e.g., glutamate and glycine) and nitric oxide (NO) synthesis (e.g., arginine and citrulline) in patients with CRPS1 (n=64) and age- and sex-matched healthy controls (n=51). Patients rated pain intensity (visual analog scale) and the subjective experience of pain intensity (McGill Pain Questionnaire). Psychological dysfunction was assessed using the SCL-90. RESULTS: Relative to controls, in CRPS1 patients, plasma levels of glutamate, arginine, taurine, and glycine were increased, and plasma levels of glutamine and the ratio of citrulline to arginine were decreased. Remarkably, in CRPS1 patients there was a highly significant inverse correlation between glutamine and glutamate, although the sum of molar concentrations of glutamate and glutamine remains unchanged. Subjective measures of pain and indicators of psychoneuroticism and emotional instability did not correlate with amino acid levels. CONCLUSION: This study shows for the first time a pronounced increase in amino acid levels in this chronic pain syndrome. The marked differences in glutamate, glutamine, glycine, taurine and arginine levels between patients and controls suggest the involvement of both the NDMA receptor and the endothelium-dependent arginine-NO system in CRPS1.

Peritoneal protein losses and cytokine generation in automated peritoneal dialysis with combined amino acids and glucose solutions.

OBJECTIVES: Protein-energy malnutrition as a consequence of deficient protein intake frequently occurs in peritoneal dialysis (PD) patients. Previously, we showed that peritoneal dialysate containing a mixture of amino acids (AA) and glucose has anabolic effects. However AA-dialysate has been reported to increase intraperitoneal protein and AA losses and the release of proinflammatory cytokines (interleukine-6 (IL-6) and tumor necrosis factor alpha (TNFalpha)). We investigated the effect of AA plus glucose (AAG) solutions on peritoneal protein losses and cytokine generation. METHODS: In 6 patients on standard automated peritoneal dialysis (APD) 12 APD sessions of 6 cycles each were performed during the night using dialysate containing 1.1% AA plus glucose or glucose alone as control. Protein losses and TNFalpha and IL-6 concentrations were measured in dialysates separately collected from nightly cycling and daytime dwell. RESULTS: The 24 hour-protein losses with AAG (median 6.7 g, range 4.7-9.4 g) were similar to control dialysate (median 6.0 g, range 4.2-9.2 g). Daytime dialysate IL-6 levels were higher after nightly AAG dialysis than after control dialysis (142 pg/ml and 82 pg/ml, respectively, P<.05). TNFalpha concentrations were very low. CONCLUSION: Nightly APD with amino acids containing dialysate was associated with an increase in peritoneal IL-6 generation during the day. The addition of AA to standard glucose dialysis solutions did not induce a significant increase of peritoneal protein losses.

Interleukin-2-Deficient mice: effect on cytokines and inflammatory cells in chronic colonic disease.

Mice deficient in interleukin-2 (IL-2-/-) develop inflammatory bowel disease resembling human ulcerative colitis. After death, macroscopic and microscopic scores were used to determine colonic inflammation. Both scores were significantly increased in the colon of IL-2-/- mice as compared to wild types mice. The level of IL-1beta 24-week-old was increased in IL-2-/- mice produced by the colon as compared with IL-2+/+ controls. However, the concentrations of IL-6 and IL-10 were not changed. The spleen weight of IL-2-/- mice was significantly increased compared with IL-2+/+ controls. We used immunochemical techniques in low-temperature paraffin-embedded spleen of IL-2-/- mice to examine pathological changes of CD4+ T cells, CD8' T cells, and CD11b+ cells. The tissue was successfully stained and was well preserved. The percentage CD4+ T cells was not significantly changed, while the percentage CD8+ T cells was significantly decreased in IL-2-/- mice compared with IL-2+/+ controls. On the other hand, the percentage CD11b+ cells was significantly increased in the spleen of IL-2-/- mice compared with IL-2+/- controls. As well as the marked difference in CD8+ and CD11b+ cells in the spleen, the increased level of IL-1beta in colonic tissue might indicate that cytotoxic T cells as well as macrophages are involved in the development and/or perpetuation of the inflammatory reactions in IL-2-/- mice.

Neuroimmune alterations in the complex regional pain syndrome.

This review focuses on some clinical aspects of the complex regional pain syndrome, such as oedema, local temperature changes and chronic pain, as a result of supposed neurogenic inflammation. Involvement of the immune system could imply the subsequent release of neuropeptides, pro-inflammatory cytokines and eicosanoids, which in turn leads to a complex cross-talk of primary and secondary generated mediators of inflammation. The development and application of drugs that act through selective receptor antagonism or enzymatic synthesis inhibition to prevent further stimulation of this cascade that could inevitably lead to chronicity of this disease are extensively discussed.

Ridogrel enemas in distal ulcerative colitis.

OBJECTIVE: To evaluate the effect of Ridogrel enemas (Janssen Research Foundation, Beerse, Belgium) on disease activity and mucosal inflammatory mediators in patients with active left-sided ulcerative colitis. DESIGN AND METHODS: Eleven patients with active left-sided ulcerative colitis were evaluated in an open non-placebo-controlled pilot study. All patients were treated with Ridogrel enemas (300 mg/40 ml once daily) over four weeks. A disease activity score based on clinical, endoscopic and histological criteria was obtained before and after treatment with Ridogrel. The concentrations of thromboxane B2 (TxB2), prostaglandin E2 (PGE2), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were measured in mucosal biopsies before and after treatment. RESULTS: One patient discontinued treatment because of progression of disease, the other ten patients tolerated the Ridogrel enemas well. Mucosal TxB2 concentration decreased significantly in all patients. The mucosal concentrations of the other inflammatory mediators (PGE2, IL-6 and TNF-alpha) were unaltered. The disease score decreased in five patients. However, clinical improvement was not always associated with a decrease in endoscopic and/or histological scores. CONCLUSIONS: This pilot study shows that Ridogrel enemas selectively reduce mucosal TxB2 concentration.

Effects of fluticasone propionate inhalation on levels of arachidonic acid metabolites in patients with chronic obstructive pulmonary disease.

BACKGROUND: In smoking COPD patients the bronchoalveolar lavage (BAL) fluid contains high numbers of inflammatory cells. These cells might produce arachidonic acid (AA) metabolites, which contribute to inflammation and an increased bronchomotor tone. AIMS: To investigate levels of AA metabolites in BAL fluid, before and after inhaled glucocorticoid therapy: fluticasone propionate (FP) 1 mg per day, or placebo. METHODS: A double-blind placebo controlled trial lasting six months. COPD patients were selected by clinical criteria and the presence of bronchial hyper-responsiveness (BHR). Lung function was recorded and in BAL fluid we counted cell numbers and measured LTB4, LTC4/D4/E4, PGE2, 6kPGF1alpha, PGF2alpha and TxB2. A control group consisted of asymptomatic smokers (n=6). RESULTS: Paired data were obtained from 9 FP treated and 11 placebo patients. BAL cells were almost exclusively alveolar macrophages. In patients and controls both cellularity and levels of AA metabolites were equal Cell numbers did not change after treatment. Statistically significant decreases after FP therapy were noticed for PGE2 (30%), 6kPGF1alpha (41%) and PGF2alpha (54%). CONCLUSIONS: In COPD, the capability of inflammatory cells to produce certain AA metabolites was decreased after inhaled FP treatment. This result is discussed in its relation to clinical effects, the influence of smoking, and the results of an earlier, similar study in asthma patients.

The effect of dexamethasone treatment on murine colitis.

BACKGROUND: Corticosteroids are used as anti-inflammatory drugs in the treatment of inflammatory bowel disease. We wanted to know whether dexamethasone (DEX) treatment could prevent dextran sulphate sodium (DSS)-induced colitis in mice. METHODS: Acute colitis was induced after oral administration of 10% DSS for 2 days. Controls received normal tap water. Five days before and during DSS or tap water exposure half the group was treated with 0.06 mg/day DEX, and the other half received saline. After the mice had been killed, macroscopic observation and histologic evaluation were used to determine the degree of colonic inflammation. RESULTS: The macroscopic score was significantly increased in untreated DSS mice (P < 0.001). The induction of colitis was not prevented by DEX pretreatment (5.9 +/- 0.9 versus 4.2 +/- 0.6; NS). In addition, the macroscopic scores of DEX-treated controls were significantly increased (1.8 +/- 0.2 versus 0.7 +/- 0.2; P = 0.007), which suggests that DEX has a stimulating effect on colitis induction. The histology score was significantly increased in untreated DSS mice compared with controls (P = 0.016). Analogous to the macroscopic scoring results, the histology score of DEX-treated controls was significantly increased compared with untreated controls (P = 0.046). CONCLUSIONS: Pretreatment with dexamethasone did not prevent the induction of acute DSS colitis, reflected by both aggravated macroscopic and histologic inflammation scores.

Time dependent production of cytokines and eicosanoids by human monocytic leukaemia U937 cells; effects of glucocorticosteroids.

In the present study the human monoblast cell line U937 has been used as a model to study the function of human mononuclear phagocytes in asthma. The kinetics of the production of eicosanoids and cytokines, which are thought to play a role in the pathogenesis of asthma, were studied. In addition, the effects of glucocorticosteroids were investigated, as these drugs are of great importance for the treatment of asthmatic patients. After stimulation with phorbol-12 myristate acetate (PMA) for 24 h, U937 cells were cultured in the absence or presence of lipopolysaccharide (LPS: 1 and 5 microg ml(-1)) and glucocorticosteroids (budesonide, fluticasone propionate and prednisolone: 10(-11), 10(-9) and 10(-7) M) for 96 h. The production of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) gradually increased in time after stimulation with LPS, whereas the transient production of tumor necrosis factor alpha (TNF-alpha) reached its maximum between 6 and 12 h. Interferon-gamma (IFN-gamma), interleukin-10 (IL-10) and leukotriene B4 (LTB4) were not detectable. All three glucocorticosteroids (budesonide, fluticasone propionate and prednisolone) completely inhibited the production of both eicosanoids and cytokines. The production of eicosanoids was more sensitive to these glucocorticoids than the production of cytokines. The observed differences in the kinetics of the production of eicosanoids and cytokines stress the importance of time course experiments in studies on the effect of drugs on mononuclear cells.

Transdermal nicotine inhibits interleukin 2 synthesis by mononuclear cells derived from healthy volunteers.

BACKGROUND: Smoking has either a beneficial or harmful effect on the course and recurrence of ulcerative colitis (UC) and Crohn's disease respectively. Transdermal application of nicotine had similar effects in UC and therefore was considered to be an effective basic drug that could be further developed in the search for new compounds in the treatment of acute exacerbations of corticosteroid-resistant UC. To clarify the hypothesis that nicotine exerts its anti-inflammatory effect in UC through selective inhibition of T-cell-derived cytokine synthesis, we studied in vivo effects of nicotine on cytokine production by human non-adherent mononuclear cells isolated from peripheral blood in a randomized, double-blind, placebo-controlled trial. METHODS: Healthy non-smoking volunteers applied for 2 weeks of nicotine patches (n = 12) with incremental doses of nicotine during the first week to achieve a maintenance dose of 15 mg per day, or placebo (n = 12). Blood was obtained before treatment and 1, 2, 3 and 6 weeks after the start of treatment. Cells were cultured in the absence or presence of phytohaemagglutinin for 48 h, and total amounts of interleukin 2 (IL-2), IL-4, IL-10, IL-13, interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) were measured. RESULTS: Transdermal nicotine caused a significant inhibition of IL-2 after 2 weeks' treatment compared with the placebo group. In addition, a diminished production of IL-10 and TNF-alpha in comparison with day 0 was observed. CONCLUSION: The beneficial effect of transdermal nicotine in ulcerative colitis may be mediated by a selective inhibition of the IL-2 production by mucosal mononuclear cells, which could result in diminished cell proliferation and consequently a reduction in the inflammatory process.

Diminished nitroprusside-induced relaxation of inflamed colonic smooth muscle in mice.

The dextran sodium sulphate (DSS) induced colitis in mice was used as a experimental model to study the contractility of murine longitudinal colonic smooth muscle during inflammation. Smooth muscle segments of proximal, middle and distal colon were mounted in organ baths. Smooth muscle contraction was induced by carbachol showing an aboral increase in activity, whereas in the inflamed middle colonic segment a marked decrease in activity was observed. The dilatative effect of sodium-nitroprusside (SNP) as a nitric oxide donor was investigated after precontraction by carbachol. Both in normal and DSS segments administration of SNP to isolated mouse colonic smooth muscle preparations caused regional differences in relaxation, the highest relaxation seen in normal proximal colonic tissue. However, this relaxation was markedly reduced in inflamed proximal preparations, associated with a diminished cGMP contents.

Smoking and nicotine in inflammatory bowel disease: good or bad for cytokines?

Smoking has either a beneficial or harmful effect on the course and recurrence of ulcerative colitis and Crohn's disease respectively. Transdermal application of nicotine had similar effects in ulcerative colitis and therefore was considered to be an effective basic drug which could be further developed in the search for new compounds in the treatment of acute exacerbations of corticosteroid resistant ulcerative colitis. In this communication the short-term use of nicotine in ulcerative colitis is reviewed.

Intestinal permeability and contractility in murine colitis.

We developed an in vitro organ bath method to measure permeability and contractility simultaneously in murine intestinal segments. To investigate whether permeability and contractility are correlated and influenced by mucosal damage owing to inflammation, BALB/c mice were exposed to a 10% dextran sulphate sodium (DSS) solution for 8 days to induce colitis. The effect of pharmacologically induced smooth muscle relaxation and contraction on permeability was tested in vitro. Regional permeability differences were observed in both control and 10% DSS-treated mice. Distal colon segments were less permeable to 3H-mannitol and 14C-PEG 400 molecules compared with proximal colon and ileum. Intestinal permeability in control vs. 10% DSS mice was not altered, although histologic inflammation score and IFN-gamma pro-inflammatory cytokine levels were significantly increased in proximal and distal colon. IL-1beta levels were enhanced in these proximal and distal segments, but not significantly different from controls. Any effect of pharmacologically induced contractility on intestinal permeability could not be observed. In conclusion, intestinal permeability and contractility are not correlated in this model of experimentally induced colitis in mice. Although simultaneous measurement in a physiological set-up is possible, this method has to be further validated.

Somatostatin does not attenuate intestinal injury in dextran sodium sulphate-induced subacute colitis.

FRom several in vitro and in vivo studies involvement of somatostatin (SMS) in intestinal inflammation emerge. Acute colitis induced in rats is attenuated by the long-acting SMS analogue octreotide. We studied the potential beneficial effect of SMS on non-acute experimental colitis. BALB/c mice received either saline, SMS-14 (36 or 120 microg daily) or octreotide (3 microg daily) subcutaneously delivered by implant osmotic pumps. A non-acute colitis was induced by administration of dextran sodium sulphate (DSS) 10% in drinking water during 7 days. DSS evoked a mild, superficial pancolitis, most characterized by mucosal ulceration and submucosal influx of neutrophils. Neither SMS-14 nor octreotide reduced mucosal inflammatory score or macroscopical disease activity, although reduction of intestinal levels of interleukin-1beta (IL-1beta), IL-6 and IL-10 during DSS was augmented both by SMS and octreotide. A slight increase of neutrophil influx was seen during SMS administration in animals not exposed to DSS. In conclusion, SMS or its long-acting analogue did not reduce intestinal inflammation in non-acute DSS-induced colitis. According to the cytokine profile observed, SMS-14 and octreotide further diminished the reduction of intestinal macrophage and Th2 lymphocyte activity.

The role of prostanoids in ozone-induced changes in airway responsiveness: receptor activation-specific prostanoid release.

We studied the effect of in vivo ozone exposure (3 ppm, 2 h) on methacholine- and histamine-induced guinea pig tracheal smooth muscle contractions in vitro and the role of cyclooxygenase products in this process. After exposure to ozone, methacholine stimulation showed a functional hyperreactivity, whereas after stimulation with histamine a hyporeactivity was observed. These effects could be explained by the release of prostanoids. In a control situation an increase in PGF(2α), PGE(2) and PGD(2) release is observed after stimulation of the histaminergic receptor system. After ozone exposure the release of prostanoids was also enhanced (unstimulated, PGF(2α) and TxB(2); histamine, PGF(2α), PGE(2); methacholine, PGF(2α), TxB(2), 6-kPGF(1α), PGE(2)). This study shows that the prostanoid release is strongly dependent on the receptor system stimulated to induce smooth muscle contraction and the importance of prostanoids in ozone-induced changes in guinea pig tracheal smooth muscle reactivity.

Response to intranasal fluticasone propionate in perennial allergic rhinitis not associated with glucocorticoid receptor characteristics.

BACKGROUND: The reduction of symptoms due to treatment with corticosteroids varies among patients with perennial rhinitis. Most patients will respond but a few patients respond less to these drugs. OBJECTIVE: To investigate the association in reduction of symptoms due to glucocorticoids and glucocorticoid receptor characteristics in patients with perennial allergic rhinitis, in vitro glucocorticoid receptor binding studies were performed with peripheral blood mononuclear cells using dexamethasone and in vitro production of mediators were measured. METHODS: During a double-blind placebo-controlled crossover study, 200 micrograms fluticasone propionate aqueous nasal spray (in the active treatment period) and placebo (in the placebo treatment period) were administered twice daily for 2 weeks to 22 patients allergic to house dust mite. At the end of both treatment periods symptoms were scored after allergen provocation (100, 1000, 10000 BU/mL) and during the 9.5 hours after this challenge. Receptor binding studies with dexamethasone were performed with peripheral blood mononuclear cells. Leukotriene B4 produced by monocytes in vitro and soluble interleukin-2 receptor released by lymphocytes in vitro and cortisol levels in plasma were determined. RESULTS: No significant partial correlations of the number of the peripheral blood mononuclear cell glucocorticoid receptors (6821 +/- 5669 binding sites per cell) and the affinity (Kd: 16.5 +/- 13.51 nmol/L) for the glucocorticoid receptors with the symptom score (placebo: 4.3 +/- 2.45 pts; fluticasone: 2.4 +/- 1.55 pts) after active treatment were found. Also no significant partial correlations of the levels of leukotriene B4 (45.6 +/- 105.3 ng/10(6) cells) produced by monocytes in vitro, soluble interleukin-2 receptor (734 +/- 237 ng/10(6) cells) released by lymphocytes in vitro and cortisol levels (571 +/- 236 ng/mL) in plasma with the symptom score after active treatment were found. CONCLUSIONS: The reduction of symptoms due to topical fluticasone propionate in patients with rhinitis and allergy to house dust mite is not correlated with the characteristics of the glucocorticoid receptor.

Effect of nicotine on large bowel mucus thickness, eicosanoids and faecal proteinase in ferrets.

BACKGROUND: Following observations on the effect of subcutaneous nicotine on rectal mucosal eicosanoids and mucus in the rabbit we have repeated the work in ferrets which may be a more suitable animal model. AIMS AND METHODS: The effect of nicotine on mucosal eicosanoids, the adherent mucus layer, and faecal proteinases in the large bowel of ferrets was examined in forty animals randomly allocated to five groups, a control and four treatment groups. They were given subcutaneous saline or nicotine via an Alzet pump in doses of 0.3, 0.6, 1.2 and 2.0 mg/kg/day for 10 days and then sacrificed; measurements were made of serum nicotine and cotinine levels, rectal mucosal eicosanoids, adherent rectal and colonic mucus thickness, and faecal proteinases. RESULTS: No significant differences were observed for any measurements, except for serum nicotine and cotinine levels, which were raised consistent with the dose given. CONCLUSION: Nicotine had no effect on measurements, which may possibly be important in the relationship between smoking and ulcerative colitis.

Prostanoids in bronchoalveolar lavage fluid do not predict outcome in congenital diaphragmatic hernia patients.

Vasoactive prostanoids may be involved in persistent pulmonary hypertension (PPH) in infants with a congenital diaphragmatic hernia (CDH). We hypothesized that increased levels of prostanoids in bronchoalveolar lavage (BAL) fluid would predict clinical outcome. We measured the concentrations of 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)), thromboxane B(2) (TxB(2)), protein, albumin, total cell count, and elastase-alpha1-proteinase-inhibitor complex in BAL fluid of 18 CDH patients and of 13 control subjects without PPH. We found different concentrations of prostanoids in BAL fluid of CDH patients with PPH: infants with a poor prognosis had either high levels of both 6-keto-PGF(1alpha) and TxB(2) compared to controls, or high levels of 6-keto-PGF(1alpha) only. TxB(2) levels showed a large variability in all CDH patients irrespective of outcome. We conclude that prostanoid levels in BAL fluid do not predict clinical outcome in CDH patients.

Lung eicosanoids in perinatal rats with congenital diaphragmatic hernia.

Abnormal levels of pulmonary eicosanoids have been reported in infants with persistent pulmonary hypertension (PPH) and congenital diaphragmatic hernia (CDH). We hypothesized that a dysbalance of vasoconstrictive and vasodilatory eicosanoids is involved in PPH in CDH patients. The levels of several eicosanoids in lung homogenates and in bronchoalveolar lavage fluid of controls and rats with CDH were measured after caesarean section or spontaneous birth. In controls the concentration of the stable metabolite of prostacyclin (6-keto-PGF(1alpha)), thromboxane A(2) (TxB(2)), prostaglandin E(2) (PGE(2)), and leukotriene B(4) (LTB(4)) decreased after spontaneous birth. CDH pups showed respiratory insufficiency directly after birth. Their lungs had higher levels of 6- keto-PGF(1alpha), reflecting the pulmonary vasodilator prostacyclin (PGI(2)), than those of controls. We conclude that in CDH abnormal lung eicosanoid levels are present perinatally. The elevated levels of 6-keto-PGF(1alpha) in CDH may reflect a compensation mechanism for increased vascular resistance.