Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection: role of Crohn's associated NOD2 gene variants.

Recognition of bacterial peptidoglycan-derived muramyl-dipeptide (MDP) by nucleotide oligomerization domain 2 (NOD2) induces crucial innate immune responses. Most bacteria carry the N-acetylated form of MDP (A-MDP) in their cell membranes, whereas N-glycolyl MDP (G-MDP) is typical for mycobacteria. Experimental murine studies have reported G-MDP to have a greater NOD2-stimulating capacity than A-MDP. As NOD2 polymorphisms are associated with Crohn's disease (CD), a link has been suggested between mycobacterial infections and CD. Thus, the aim was to investigate if NOD2 responses are dependent upon type of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium paratuberculosis (MAP) (a G-MDP-containing bacteria associated with CD) was investigated in human peripheral blood mononuclear cells (PBMCs). A-MDP and M. segmatisΔnamH induced significantly higher tumour necrosis factor (TNF)-α protein levels in healthy wild-type NOD2 PBMCs compared with G-MDP and M. segmatis. NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced production of interleukin (IL)-1ß and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD.

Assessment of the validity of a multigene analysis in the diagnostics of inflammatory bowel disease.

OBJECTIVES: The findings of a previous multigene study indicated that the expression of a panel of seven specific genes had strong differential power regarding inflammatory bowel disease (IBD) versus non-IBD, as well as ulcerative colitis (UC) versus Crohn's disease (CD). This prospective confirmatory study based on an independent patient cohort from a national Danish IBD centre was conducted in an attempt to verify these earlier observations. DESIGN, SETTING AND PARTICIPANTS: A total of 119 patients were included in the study (CD, UC and controls). Three mucosal biopsies were retrieved from the left side of the colon of each patient. RNA was extracted, and RT-PCR was performed to retain expression profiles from the seven selected genes. Expression data from the training set (18 CD, 20 UC and 20 controls) were used to build a classification model, using quadratic discriminant analysis, and data from the test set (20 CD, 21 UC and 20 controls) were used to test the validity of the model. RESULTS: The present investigation did not confirm the previous observation that a panel of seven specific genes is able to distinguish between patients with CD and UC, whereas the discriminative power for IBD versus control subjects was substantiated. CONCLUSION: Our results fail to demonstrate that the previously identified seven-gene classification model is able to discriminate between CD and UC but suggest that the gene panel merely discriminates between inflamed and noninflamed colonic tissue. Thus, a reliable and simple diagnostic tool is still warranted for optimal diagnosis and treatment of patients with IBD, especially the subgroup with unclassified disease.

Use of biological molecules in the treatment of inflammatory bowel disease.

The introduction of biological agents (i.e. antitumour necrosis factor-α and anti-integrin treatments) for the treatment of inflammatory bowel disease (IBD) [i.e. Crohn's disease (CD) and ulcerative colitis] has led to a substantial change in the treatment algorithms and guidelines, especially in CD. However, many questions still remain about the true efficacy and the best treatment regimens. Thus, a need for further treatment options still exists as up to 40% of IBD patients treated with the presently available biologicals do not have positive clinical responses. Better patient selection might maximize the clinical benefit for those in most need of an effective therapy to avoid disabling disease whilst also minimizing the complications associated with therapy. Further, the 'trough-level strategy' may help clinicians to optimize therapy and to avoid loss of response and/or immunogenicity. The idea behind this dosage regimen is that correct dosing must ensure that the patient's lowest level of drug concentration (i.e. the trough level) occurring just before the next drug administration is high enough for the full effect to be seen. Controversy continues regarding the appropriate use of biologicals; therefore, in this review, we focus on considerations that might lead to a more rational strategy for antitumour necrosis factor-α agents in IBD, emphasizing the situations in which the risks may outweigh the benefits. Finally, the need for an appropriate strategy for stopping biological treatment is discussed.

Mitogen activated protein kinases: a role in inflammatory bowel disease?

Since their discovery more than 15 years ago, the mitogen activated protein kinases (MAPK) have been implicated in an ever-increasingly diverse array of pathways, including inflammatory signalling cascades. Inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn's disease, are characterized by the perpetual production of inflammatory mediators. Research into the transduction pathway behind this over-production has highlighted the potential mediating role for the MAPKs and their related signalling components. This review highlights some of the research into the role for the MAPKs and their related signalling proteins in influencing the progression of IBD.

Systematic review: coxibs, non-steroidal anti-inflammatory drugs or no cyclooxygenase inhibitors in gastroenterological high-risk patients?

Selective cyclooxygenase-2 inhibitors have been marketed as alternatives of conventional, non-steroidal anti-inflammatory drugs with the purpose of reducing/eliminating the risk of ulcer complications. Unexpectedly, randomized-controlled trials revealed that long-term use of coxibs, such as rofecoxib, significantly increased the risk of myocardial infarction and stroke, while the use of valdecoxib was associated with potentially life-threatening skin reactions. Subsequently, rofecoxib and valdecoxib were withdrawn from the market. Although more strict precautions for other coxibs, such as celecoxib, etoricoxib, lumiracoxib and parecoxib, may be accepted/recommended by regulatory agencies, a critical review of published data suggests that their use may not be justified - even in high-risk patients - taking benefits, costs and risks into consideration. Clinicians should, therefore, never prescribe coxibs to patients with cardiovascular risk factors, and should only reluctantly prescribe coxibs to patients with a history of ulcer disease or dyspepsia to overcome persistent pain due to, e.g. rheumatoid arthritis or osteoarthritis. Instead, they should consider using conventional non-steroidal anti-inflammatory drugs in combination with a proton pump inhibitor or a prostaglandin analogue, especially for patients with increased cardiovascular risks, i.e. established ischaemic heart disease, cerebrovascular disease and/or peripheral arterial disease, or alternatively acetaminophen. An evidence-based algorithm for treatment of a chronic arthritis patient with one or more gastrointestinal risk factors is presented.

Insulin action and insulin secretion in identical twins with MODY. Evidence for defects in both insulin action and secretion.

To evaluate the pathogenetic mechanisms responsible for development of diabetes in the genetically inherited disease maturity-onset diabetes of the young (MODY), we have investigated a pair of identical twins (19 yr old) from a MODY family. One twin had nondiabetic fasting plasma glucose values but impaired glucose tolerance (IGT), whereas the other suffered from frank diabetes (fasting plasma glucose 12.5 mM). Differences in insulin secretion pattern and/or insulin action between the twins is supposed to be responsible for development of hyperglycemia in MODY. On the other hand, identical defects in insulin secretion and action in the twins may point to the primary genetic defect in MODY. Therefore, our aim was to investigate insulin secretion and insulin action in the twins to find these differences and similarities. We found that fasting plasma insulin and C-peptide values were slightly increased in the twins, whereas the responses of insulin and C-peptide to oral glucose tolerance tests (OGTT) and meals were similar in the twins and within normal range. The insulin responses to OGTT were, however, lower than expected from the glucose values, indicating a beta-cell defect. Despite elevated plasma insulin levels, basal hepatic glucose output (HGO) was normal in the IGT twin but increased by 75% in the diabetic twin. The maximally inhibitory effect of insulin on HGO, when estimated at euglycemia, was normal in the IGT twin but reduced by 60% in the diabetic twin. Furthermore, the maximal insulin-mediated glucose uptake in peripheral tissues was reduced by 40% in the diabetic twin.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved in vivo insulin effect during continuous subcutaneous insulin infusion in patients with IDDM.

It has recently been shown that conventionally treated IDDMs are insulin resistant. Using the insulin clamp technique, we studied the influence of metabolic status on the in vivo insulin effect in these patients. Eleven IDDMs, treated conventionally with diet and insulin for 10.7 +/- 5.6 yr, were studied before and after continuous subcutaneous insulin infusion (CSII) treatment (with a portable pump) for 6 mo. We found that conventionally treated diabetic subjects were extremely insulin resistant with regard to peripheral glucose uptake. Glucose uptake, at an insulin concentration of about 80 microU/ml, was 4.3 +/- 2.0 mg/kg X min before treatment compared with 11.5 +/- 4.0 mg/kg X min in normals (P less than 0.01). After pump treatment for 6 mo, metabolic control improved significantly (HbA1c decreased from 8.9 +/- 1.9% to 7.4 +/- 1.2%, P less than 0.01) and, parallel to that, glucose uptake increased about 80% to 7.5 +/- 3.5 mg/kg X min (P less than 0.01). The mean daily plasma FFA level decreased from 0.32 +/- 0.10 mmol/L to 0.21 +/- 0.07 mmol/L (P less than 0.01); this variable was negatively correlated to the glucose clearance rate (r = -0.62, P less than 0.01). There was no statistically significant change in mean daily plasma insulin and plasma growth hormone levels or in 24-h cortisol excretion in the urine (P greater than 0.1). The insulin binding capacity of serum IgG was also unchanged, and there was no significant relationship between this quantity and glucose clearance rates (r = 0.18, P greater than 0.1). We conclude that conventionally treated IDDMs are insulin resistant with regard to peripheral glucose uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant human tumour necrosis factor increases cytosolic free calcium in murine fibroblasts and stimulates inositol phosphate formation in L-M and arachidonic acid release in 3T3 cells.

Stimulation of murine L-M and 3T3 fibroblasts with human recombinant tumour necrosis factor (rTNF) resulted in an increase in the cytosolic free Ca2+ concentration ([Ca2+]i). In 3T3 cells rTNF also induced release and metabolization of arachidonic acid, whereas in L-M cells rTNF provoked rapid increases in the levels of inositol mono-, bis- and trisphosphates (IP1, IP2 and IP3). In these cells the Ca2+ response was also observed in Ca2+ free medium, suggesting that rTNF promotes mobilization of Ca2+ from intracellular stores. In 3T3 cells, however, Ca2+ originated from the extracellular space, since the response was abolished in medium containing 1 mM EGTA. Both rTNF-induced calcium responses were inhibited by a specific rabbit IgG antibody to rTNF but not by 1-verapamil, a blocker potential-operated calcium channels. These results suggest that increased formation of inositol phosphates, arachidonic acid release and increased cytosolic free Ca2+ are involved in the biological effects of rTNF. However, rTNF generate these signals by different mechanisms depending upon the target cell.

Insulin action in insulin-dependent diabetics after short-term thiazide therapy.

The influence of short-term thiazide treatment on peripheral tissue and liver sensitivity to insulin in insulin-dependent diabetes mellitus was determined by the euglycemic insulin clamp technique. A sequential three-step hyperinsulinemic clamp was performed in six insulin-dependent diabetics before and after 2 wk of hydroflumethiazide (HFT) administration in a daily dose of 75 mg. Insulin was infused at rates of 0.5, 2.0, and 4.0 mU X kg-1 X min-1, and each dose was given for at least 120 min. Glucose uptake during the last 30 min of each step was almost identical in the two situations (2.7 +/- 0.6 vs. 2.4 +/- 0.5 mg X kg-1 X min-1, 9.6 +/- 0.9 vs. 9.7 +/- 1.2 mg X kg-1 X min-1, and 12.0 +/- 1.3 vs. 12.6 +/- 1.5 mg X kg-1 X min-1). Serum insulin levels were also similar, and blood glucose was kept at 100 +/- 3, 99 +/- 4, and 97 +/- 3 mg/dl before thiazides and at 93 +/- 6, 93 +/- 6, and 94 +/- 6 mg/dl after thiazides. Another five insulin-dependent diabetics were infused with tritiated glucose followed by insulin infusion at two rates: 0.45 and 1.0 mU X kg-1 X min-1. Basal glucose output was comparable before and after thiazides (3.63 +/- 0.24 vs. 2.97 +/- 0.26 mg X kg-1 X min-1), as was the liver response to increasing insulin concentrations. The metabolic state as assessed by HbA1c and fasting blood glucose did not differ in the two experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin resistance in skeletal muscles in patients with NIDDM.

Skeletal muscles in patients with non-insulin-dependent diabetes mellitus (NIDDM) are resistant to insulin; i.e., the effect of insulin on glucose disposal is reduced compared with the effect in control subjects. This defect has been found to be localized to the nonoxidative pathway of glucose disposal; hence, the deposition of glucose, as glycogen, is abnormally low. This defect may be inherited, because it is present in first-degree relatives to NIDDM patients two to three decades before they develop frank diabetes mellitus. The cellular defects responsible for the abnormal insulin action in NIDDM patients is reviewed in this article. The paper focuses mainly on convalent insulin signaling. Insulin is postulated to stimulate glucose storage by initiating a cascade of phosphorylation and dephosphorylation events, which results in dephosphorylation and hence activation of the enzyme glycogen synthase. Glycogen synthase is the key enzyme in regulation of glycogen synthesis in the skeletal muscles of humans. This enzyme is sensitive to insulin, but in NIDDM patients it has been shown to be completely resistant to insulin stimulation when measured at euglycemia. The enzyme seems to be locked in the glucose-6-phosphate (G-6-P)-dependent inactive D-form. This hypothesis is favored by the finding of reduced activity of the glycogen synthase phosphatase and increased activity of the respective kinase cAMP-dependent protein kinase. A reduced glycogen synthase activity has also been found in normoglycemic first-degree relatives of NIDDM patients, indicating that this abnormality precedes development of hyperglycemia in subjects prone to develop NIDDM. Therefore, this defect may be of primary genetic origin. However, it does not appear to be a defect in the enzyme itself, but rather a defect in the covalent activation of the enzyme system. Glycogen synthase is resistant to insulin but may be activated allosterically by G-6-P. This means that the defect in insulin activation can be compensated for by increased intracellular concentrations of G-6-P. In fact, we found that both hyperinsulinemia and hyperglycemia are able to increase the G-6-P level in skeletal muscles. Thus, insulin resistance in the nonoxidative pathway of glucose processing can be overcomed (compensated) by hyperinsulinemia and hyperglycemia. In conclusion, we hypothesize that insulin resistance in skeletal muscles may be a primary genetic defect preceding the diabetic state. The cellular abnormality responsible for that may be a reduced covalent insulin activation of the enzyme glycogen synthase.(ABSTRACT TRUNCATED AT 400 WORDS)

Deviations in human gut microbiota: a novel diagnostic test for determining dysbiosis in patients with IBS or IBD.

BACKGROUND: Dysbiosis is associated with many diseases, including irritable bowel syndrome (IBS), inflammatory bowel diseases (IBD), obesity and diabetes. Potential clinical impact of imbalance in the intestinal microbiota suggests need for new standardised diagnostic methods to facilitate microbiome profiling. AIM: To develop and validate a novel diagnostic test using faecal samples to profile the intestinal microbiota and identify and characterise dysbiosis. METHODS: Fifty-four DNA probes targeting ≥300 bacteria on different taxonomic levels were selected based on ability to distinguish between healthy controls and IBS patients in faecal samples. Overall, 165 healthy controls (normobiotic reference collection) were used to develop a dysbiosis model with a bacterial profile and Dysbiosis Index score output. The model algorithmically assesses faecal bacterial abundance and profile, and potential clinically relevant deviation in the microbiome from normobiosis. This model was tested in different samples from healthy volunteers and IBS and IBD patients (n = 330) to determine the ability to detect dysbiosis. RESULTS: Validation confirms dysbiosis was detected in 73% of IBS patients, 70% of treatment-naïve IBD patients and 80% of IBD patients in remission, vs. 16% of healthy individuals. Comparison of deep sequencing and the GA-map Dysbiosis Test, (Genetic Analysis AS, Oslo, Norway) illustrated good agreement in bacterial capture; the latter showing higher resolution by targeting pre-determined highly relevant bacteria. CONCLUSIONS: The GA-map Dysbiosis Test identifies and characterises dysbiosis in IBS and IBD patients, and provides insight into a patient's intestinal microbiota. Evaluating microbiota as a diagnostic strategy may allow monitoring of prescribed treatment regimens and improvement in new therapeutic approaches.

Comparative studies of the colonic in situ expression of intercellular adhesion molecules (ICAM-1, -2, and -3), beta2 integrins (LFA-1, Mac-1, and p150,95), and PECAM-1 in ulcerative colitis and Crohn's disease.

A dysregulated local immune defense with a constant influx of leukocytes provides a basis for continuous intestinal inflammation in ulcerative colitis (UC) and Crohn's disease (CD). Cell adhesion molecules are pivotal for the migration of leukocytes from the circulation toward the colonic epithelium. A study quantifying the cells expressing intercellular adhesion molecules (ICAMs), beta2 integrins, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in the colon was performed to illustrate the leukocyte migration pathway in inflammatory bowel disease. Serial colonic sections (10 UC, 10 CD, and 10 controls) were stained immunohistochemically for ICAM-1, ICAM-2, ICAM-3, CD11a, CD11b, CD18, and PECAM-1. Cell adhesion molecule expression was evaluated quantitatively with reference to topographic localization. In UC, polymorphonuclear leukocytes (PMNs) in contact with the crypt epithelium and in crypt abscesses expressed CD11b. CD tissue was characterized by CD11a-, CD11c-, and ICAM-1-expressing cells. ICAM-1 was detected on endothelial cells, leukocytes, and apical parts of epithelial membranes, whereas ICAM-2 was expressed on basal epithelial membranes. Most infiltrating leukocytes expressed ICAM-3, whereas perivascular mononuclear cells expressed PECAM-1. Interestingly, the epithelial basement membrane in UC stained for CD18. In conclusion, CD11b, CD18, and ICAM-2 seem to be important for PMN transepithelial migration in UC, whereas CD11a, CD11c, ICAM-1, and ICAM-3 seem central in leukocyte locomotion and aggregation in CD. Differentiated upregulation of cell adhesion molecules is suggested to be essential for the diversities between UC and CD.

Chemotactic properties of ICAM-1 and PECAM-1 on neutrophil granulocytes in ulcerative colitis: effects of prednisolone and mesalazine.

BACKGROUND: ICAM-1 seems to exhibit effects other than passive leucocyte/endothelial interaction. AIM: To investigate the attracting properties of selected adhesion molecules, assessing the influence of the two major anti-inflammatory drugs in ulcerative colitis, prednisolone and mesalazine. METHODS: Circulating neutrophils (11 ulcerative colitis, 15 controls) were assessed in microchemotaxis chambers by the leading front technique, using physiologically relevant concentrations of ICAM-1 (0.005-5000 pM), PECAM-1 (0.001-1000 nM), and P-selectin (0.01-100 nM). Neutrophils pre-incubated with prednisolone (10(-8)-10(-4) M) or mesalazine (0.65-10. 4 nM) were assessed towards ICAM-1. RESULTS: Migration of neutrophils towards ICAM-1 showed a bell-shaped curve with a maximum at 5 pM (migration: 37.7 microm; P<0.001), whereas PECAM-1 attracted neutrophils equally in the range of 0.1-10 nM (25.0 microm; P<0.001). P-selectin had no cell-attracting effect. No differences were detected between cells from ulcerative colitis patients and controls. Pre-treatment with prednisolone decreased the cell attracting effect of ICAM-1 in a dose-dependent manner to 72% of the basal migration (P<0.001). Conversely, prednisolone showed a pro-chemokinetic effect by increasing the spontaneous locomotion of neutrophils by 40% (P<0.001). CONCLUSIONS: Specific chemotactic properties were observed for ICAM-1 and PECAM-1. Prednisolone exhibited a dual effect in inhibiting the ICAM-1-mediated migration and stimulating the general locomotion of neutrophils.

Inhibition of intestinal macrophage chemotaxis to leukotriene B4 by sulphasalazine, olsalazine, and 5-aminosalicylic acid.

Purified intestinal macrophages obtained at resections for colonic neoplasms were investigated for chemotaxis to leukotriene B4 (LTB4) by the Millipore filter assay and leading front technique. Possible inhibition by drugs effective in the treatment of chronic inflammatory bowel disease (sulphasalazine, olsalazine, its active moiety 5-aminosalicylic acid (5-ASA), and the 5-ASA metabolite N-acetylated-5-ASA (ac-5-ASA)) was tested at therapeutic colonic concentrations of 0.01-10 mM. Leukotriene B4 at a dose of 10 nM was equipotent with casein (5 g litre-1) as regards chemoattraction of macrophages. Sulphasalazine, olsalazine and 5-ASA were potent inhibitors of macrophages chemotaxis to LTB4 with IC50 values of 0.43, 0.39 and 0.24 mM, respectively. These concentrations are below the lowest concentration of 5-ASA (2 mM) in the colonic lumen during conventional sulphasalazine treatment of patients with chronic inflammatory bowel disease. The inhibition of macrophage chemotaxis by these drugs may be important for this limitation of the local inflammatory process in chronic inflammatory bowel disease, and may in part explain the beneficial effect of systemic and local treatment with sulphasalazine. Leukotriene B4 appears to be an important inflammatory mediator for the activation of macrophages in colonic inflammation.

Review article: the treatment of inflammatory bowel disease with 6-mercaptopurine or azathioprine.

The thioguanine derivative, azathioprine, is a prodrug of 6-mercaptopurine that is further metabolized by various enzymes present in the liver and gut. Azathioprine and 6-mercaptopurine have been used in the treatment of inflammatory bowel disease, i.e. ulcerative colitis and Crohn's disease, for more than 30 years. However, widespread use of azathioprine or 6-mercaptopurine in inflammatory bowel disease is of more recent origin, the primary reason being a long-standing debate on the efficacy of these agents in inflammatory bowel disease. Both drugs are slow acting, which is why clinical efficacy cannot be expected until several weeks or even months of treatment have elapsed. Consequently, azathioprine and 6-mercaptopurine have no place as monotherapy in the treatment of acute relapsing inflammatory bowel disease. Today, azathioprine and 6-mercaptopurine are the most commonly used immunomodulatory drugs in the treatment of inflammatory bowel disease. Their clinical effects are probably identical, although their exact mode of action is still unknown. The mode of action of azathioprine is thought to be multifactorial, including conversion to 6-mercaptopurine (which acts as a purine antimetabolite), possible blockade of thiol groups by alkylation, inhibition of several pathways in nucleic acid biosynthesis (preventing proliferation of cells involved in the determination and amplification of the immune response) and damage to DNA through the incorporation of thiopurine analogues. However, 6-thioguanine nucleotides may accumulate in toxic doses in myeloid precursor cells, resulting in life-threatening myelosuppression. Azathioprine and 6-mercaptopurine are further known to alter lymphocyte function, reduce the number of lamina propria plasma cells and affect natural killer cell function. The purpose of this comprehensive review is to suggest guidelines for the application of azathioprine and 6-mercaptopurine in the treatment of inflammatory bowel disease.

Tolerability of interferon alpha-2b, a possible new treatment of active Crohn's disease.

BACKGROUND AND AIMS: Due to the need for new principles for the treatment of Crohn's disease and due to the documented immunomodulatory effects of interferon alpha, the tolerability and effect(s) of interferon alpha-2b (Introna) in active Crohn's disease were examined in a pilot study. METHODS: Five patients with active Crohn's disease (activity index (CDAI) scores of 235-517), were treated with interferon alpha-2b for 12 weeks. RESULTS: All patients tolerated the treatment, but developed influenza-like symptoms, which were fully controlled by paracetamol. Two patients obtained partial remission with a decline in activity index scores of 39% and 50%. The activity of 2',5'-oligoadenylate synthetase, which together with two other interferon-induced proteins, neopterin and beta 2-microglobulin were increased during treatment, indicated clearly an in vivo uptake of interferon. Sedimentation rate, C-reactive protein, orosomucoid, albumin, specific inflammatory markers: soluble interleukin-2 alpha-receptors (sIL-2R) and intercellular adhesion molecule-1 (ICAM-1) did not show any changes before or after treatment. CONCLUSION: Future multicentre investigations are required to evaluate the clinical effect of interferon alpha-2b treatment in active Crohn's disease.

Induction of endogenous arachidonic acid metabolism in human neutrophils with snake venom phospholipase A2, immune complexes, and A23187.

The stimuli responsible for eicosanoid secretion of phagocytes in chronic inflammatory disorders like rheumatoid arthritis and chronic inflammatory bowel disease are unknown. Phospholipase A2 (PLA2), found in Russelli vipera snake venom, has been proposed to be more than 100 times more potent on a molar basis than A23187 in releasing leukotriene B4 (LTB4) from porcine neutrophils. Therefore, this enzyme was investigated as a challenger of human neutrophils (PMNs) and compared with immune complexes and A23187. 1-14C-Arachidonic acid (AA) was incorporated into purified human PMNs until steady state conditions were obtained. AA release and metabolism were stimulated with either PLA2 isoenzyme of Russelli vipera, immune complexes, or A23187. The radioactive eicosanoids released were extracted and separated by thin layer chromatography, followed by autoradiography and quantitative laser densitometry. Stimulation with PLA2, immune complexes, or A23187 resulted in LTB4 formation of 0%, 1.8%, and 5.3%, respectively, of total released radioactivity. In conclusion, Russelli vipera PLA2 does not stimulate AA-release and metabolism in human PMNs, and immune complexes are weak as compared to the unphysiologic challenger A23187 in this respect.

Effect of the leukotriene LTD4/LTE4 antagonist, SR 2640, in ulcerative colitis: an open clinical study.

This investigation was performed in order to examine the role of sulfidopeptide-leukotrienes in a chronic inflammatory bowel disease, ulcerative colitis, by use of the recently developed LTD4/LTE4 antagonist, SR 2640 (2-[3-(2-quinolylmethoxy)phenylamino]benzoic acid). Eight ulcerative colitis patients with a mild to moderate disease activity were included in this open and uncontrolled study and SR 2640, 250 mg t.i.d., was administered for 6 weeks. Treatment of the patients with SR 2640 reduced the inhibitory effect of LTD4 on LTB4-directed chemotaxis of neutrophils purified from their blood. This indicates that the dose administered was sufficiently high to obtain systemic LTD4 receptor antagonism. Three of the 8 patients were in clinical remission at the end of the study, and the lack of clinical symptoms persisted for at least 2 months after discontinuing the drug. The condition of 3 patients was unchanged, and that of 2 patients deteriorated after 5 weeks, requiring treatment with sulphasalazine and steroids. SR 2640 was well tolerated by all patients. In a previously published study dealing with 4 weeks sulphasalazine treatment in the same category of patients, remission rates of 5% and 25% were found in the placebo and sulphasalazine groups, respectively, and the remission rate of SR 2640 thus seems to be of the same magnitude as that of sulphasalazine. The serum and faecal concentrations of SR 2640, and its metabolite, the beta-glucuronide, were found to be lower in ulcerative colitis patients as compared to healthy volunteers, and it is therefore possible that altered pharmacokinetics of SR 2640 is present in patients with chronic inflammatory bowel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Signs, symptoms, metastatic spread and metabolic behavior of neuroblastomas treated in Denmark during the period 1943-1980.

The clinical manifestations of 253 neuroblastoma cases in childhood, treated in Denmark from 1943 to 1980, were reviewed. Most striking was the vagueness of symptoms in the majority of patients, only a few of whom exhibited the symptoms strongly suggestive of a neuroblastoma (i.e. the Horner syndrome, the watery diarrhoea syndrome, the dancing eye syndrome). The vagueness of the symptoms might have led to fatal procrastination of the diagnosis. The diagnostic delay has, however, no independent prognostic significance for survival in our patients (p = 0.09). The maximal tumour spread was recorded for all 253 patients, and the distribution of metastases was in accordance with the "soil-seed" hypothesis. The tumour spreads with equal frequency by local growth, by lymphatic vessels to distant lymph nodes, and by blood to bone. Only in widely disseminated tumours are metastases to the lungs, the meninges, the brain, and the reproductive organs seen to occur. Eighty-five percent of the patients, for whom data were available, excreted VMA above the normal value for their age, and 43% excreted Norepinephrine + Epinephrine (N + E) above normal levels. The excretion of both VMA and N + E was significantly correlated to stage, and thus to prognosis. Neither the level of VMA excretion nor the level of N + E had any bearing on the survival when age and stage were adjusted for. Serial VMA and N + E determinations show that patients with normal values for these parameters had significantly better prognosis than patients with elevated values during the first, second, third and fourth trimesters after the initiation of treatment. Increasing values in the individual patient were associated with a poor prognosis. We found no correlation between the initial leucocyte count and survival when age and stage were adjusted for.

Chromosome abnormalities, cellular DNA content, oncogene amplification and growth pattern in agar culture of human neuroblastomas.

The association of ability to grow in vitro, non-random chromosome abnormalities, DNA ploidy and oncogene amplification with prognosis may lead to a better understanding of the biology of neuroblastomas. In a pilot study fresh tumour tissue was obtained from 4 consecutive patients at the Department of Paediatric Surgery, Rigshospitalet, Denmark. Chromosome abnormalities were detected in 3 out of 3 successfully karyotyped tumours, and one or more aneuploid stem lines were detected in 4 out of 4 tumours using flow cytometry. The N-myc oncogene was amplified in 1 out of 3 tumours tested. Continuous cell lines could be established from all 3 advanced stage tumours. This pilot study has shown that fresh tumour tissue can be obtained and successfully studied for various fundamental aspects of the biology of neuroblastomas.