Effects of probucol on hepatic tumor necrosis factor-α, interleukin-6 and adiponectin receptor-2 expression in diabetic rats

Background and Aims:  Probucol is a lipid-lowering agent with anti-oxidant effects. Oxidative stress and inflammation are important in the pathophysiology of insulin resistance. We aimed to evaluate the effects of probucol on liver histological changes, serum and hepatic levels of adipokines in rats with high fat-induced type 2 diabetes (T2D).
Methods:  Thirty-six rats were divided into a normal control group, a high fat-induced T2D group and a probucol treatment group. After six weeks of treatment with probucol, we evaluated liver histological changes and measured homeostasis model assessment index (HOMA-IR), serum superoxide dismutase (SOD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor (TNF)-α, interleukin (IL)-6, adiponectin and hepatic TNF-α, IL-6 and adiponectin receptor-2 (adipoR2) mRNA.
Results:  The degree of hepatic steatosis and inflammation, HOMA-IR, serum ALT, TNF-α and IL-6 concentrations, and hepatic TNF-α and IL-6 mRNA expression in diabetic rats were significantly higher compared with normal controls. Serum SOD and adiponectin concentrations and hepatic adipoR2 mRNA expression in diabetic rats were significantly lower compared with normal controls. Probucol significantly reduced the degree of hepatic steatosis, HOMA-IR, serum ALT, TNF-α and IL-6 concentrations, and hepatic TNF-α and IL-6 mRNA expression. Probucol significantly raised serum SOD and adiponectin concentrations and hepatic adipoR2 mRNA expression.
Conclusions:  In rats with high fat-induced T2D, treatment with probucol improved insulin sensitivity, hepatic steatosis by raising circulating adiponectin and hepatic adipoR2 levels, in addition to reducing pro-inflammatory cytokines in the circulation and liver.     

The role of interleukin-1 and tumour necrosis factor-α in human multiple myeloma

This study investigates the capacity of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) to induce interleukin-6 (IL-6) production in freshly isolated myeloma cells (MC) and bone marrow-derived stromal cells (MSC). Recombinant human (rh) IL-1 alpha, IL-1 beta and TNF-alpha augmented production of IL-6 in human MC. IL-6 was determined on a factor-dependent Cess cell line. This activity was completely abrogated by anti-IL-6 antibodies. Prior incubation of IL-1 alpha, IL-1 beta and TNF-alpha with their respective antibodies inactivated the ability of recombinant cytokines to stimulate the release of IL-6 from myeloma cells. IL-1 alpha, IL-1 beta and TNF-alpha enhanced 3H-TdR uptake in myeloma cells through IL-6, as antibodies to IL-6 completely abolished the DNA synthesis induced by culture supernatants of MC exposed to these cytokines. rhIL-6 reversed the inhibitory action of anti-IL-6 antibodies and reinduced DNA synthesis in MC. Next we found that IL-1 alpha, IL-1 beta and TNF-alpha induced MSC to produce IL-6. In contrast, supernatants of unstimulated MSC did not contain detectable IL-6 biologic activity. Further data demonstrated that human MC were able to induce IL-6 production in MSC. The stimulatory activities of MC appeared to be mediated through endogenously released IL-1, as the addition of antibodies towards IL-1 at the initiation of cocultures completely abrogated the IL-6 production. We conclude from our data that IL-1 and TNF-alpha may play an important role in the pathogenesis of human multiple myeloma.     

Human neutrophil lipocalin is a unique marker of neutrophil inflammation in ulcerative colitis and proctitis

BACKGROUND AND AIM: Accumulation and infiltration by neutrophil granulocytes is a prominent feature in the local inflammatory process in ulcerative colitis (UC). The present study was performed to evaluate human neutrophil lipocalin (HNL) as a specific neutrophil marker in the inflamed lesions of the colon and rectum in patients with colitis and proctitis. METHODS: The activity of intestinal neutrophils with respect to release of granule proteins was studied in 18 patients with UC (10 with colitis and eight with isolated proctitis) and in 18 healthy controls using perfusion fluid and biopsies from the sigmoid colon and rectum. The released amounts of the neutrophil granule proteins HNL and myeloperoxidase (MPO) were determined by radioimmunoassays, and the location of HNL and MPO in biopsies from colonic mucosa was examined by immunohistochemistry. RESULTS: Mucosal release of HNL and MPO was increased 10-55-fold in patients with colitis and proctitis compared with controls. Their bowel biopsies demonstrated that only neutrophils were stained with anti-HNL. We also found correlations between HNL and levels of granulocyte/macrophage-colony stimulating factor (GM-CSF) and interleukin 8 (IL-8) in perfusion fluids from the sigmoidal segments of patients with proctitis, between HNL and GM-CSF in rectal segments in patients with proctitis, and in sigmoidal segments in patients with colitis. CONCLUSION: We conclude that the increased release of HNL and MPO in colorectal perfusion fluids indicates neutrophil involvement in the local inflammatory process, and suggest that HNL may serve as a specific marker of intestinal neutrophil activation in UC. GM-CSF, and to some extent IL-8, may play a role in neutrophil accumulation and priming in this disease.     

In vitro inhibition of tumour necrosis factor-α and interleukin-6 production by intravenous immunoglobulins

In vitro data about the action of pooled immunoglobulins (Ig) on cytokine (CK) production are controversial. The recent finding of natural antibodies against staphylococcal toxins neutralizing superantigen-induced activation prompted us to design an assay determining their ability to modulate staphylococcal enterotoxin B (SEB) induced CK production (IL-6 and TNF-α). Presence of anti-SEB antibodies was demonstrated by a dot-blot assay in the three preparations tested. Preincubation of SEB with pooled Ig prior to addition into the test tube containing PBMCs (neutralizing condition) resulted in a strong inhibition of both TNF-α and IL-6 release (TNFα: 59 ± 5% inhibition, P <0.0001; IL-6: 71 ± 7% inhibition. P <0.0001, n = 15). Anti-CD3 MoAb-induced CK production was not modified. During our study it was found that experimental conditions were critical to observe this inhibitory effect. Reversing the previous procedure by adding PBMCs into the test tube containing pooled Ig mixed with SEB resulted in a marked induction of TNF-α and IL-6 production. The same observation was made when pooled Ig solely was added (coating condition). F(ab')₂ fragments of pooled Ig displayed similar inhibitory capacity when added in neutralizing condition, indicating that the mechanism involved was not Fc dependent. The fragments lost the activating properties of intact Ig when incubated in coating condition, showing that Fc receptor activation occurs in this setting.
The present work demonstrates that inhibition of SEB-induced CKs release by pooled Ig can be achieved by SEB neutralization, provided that the experimental conditions avoid activation through the Fc receptor. It can be assumed that similar mechanisms take place in some clinical conditions during which pooled Ig are infused.     

中性粒细胞明胶酶相关脂质运载蛋白单核细胞趋化蛋白-1及肿瘤坏死因子样凋亡的微弱诱导剂在狼疮肾炎中的临床意义

目的 探讨狼疮肾炎患者体液中性粒细胞明胶酶相关脂质运载蛋白(NGAL)、单核细胞趋化蛋白-1(MCP-1)和肿瘤坏死因子样凋亡的微弱诱导剂(TWEAK)水平的临床意义.方法 采用酶联免疫吸附法检测51例系统性红斑狼疮(SLE)患者的血清和尿中NGAL、MCP-1和TWEAK水平,其中狼疮肾炎27例、非狼疮肾炎24例.并采集临床资料.采用t检验、Mann-Whitney U检验、Pearson和Spearman 秩相关分析进行统计学分析.结果 ①血清NGAL水平狼疮肾炎组为(122±70)ng/ml高于非狼疮肾炎组(56±34)ng/ml (P＜0.01).血清NGAL与整体SLE疾病活动指数(SLEDAI)评分、肾外SLEDAI评分、肾SLEDAI评分、尿蛋白定量(24 h)、血肌酐水平呈正相关(r=-0.408、0.431、0.339、0.403和0.585,P均＜0.05),与血清C3呈负相关(r=-0.396,P＜0.01).尿NGAL水平与慢性指数呈正相关(r=0.719,P＜0.01).②血清MCP-1狼疮肾炎组(284±1 13) pg/ml高于非狼疮肾炎组(173±69)pg/ml,P＜0.01;尿MCP-1水平在狼疮肾炎组M=1154、(P75 41 178,P5 341)pg/mg肌酐高于非狼疮肾炎组M=456、(P75 714,P25 114)pg/mg 肌酐(P＜0.01).血清MCP-1水平与整体SLEDAI评分、肾外SLEDAI评分、肾SLEDAI评分、尿蛋白定量(24 h)、血肌酐水平均呈正相关(r=0.340、0.416、0.385、0.574和0.654,P均＜0.05),与血清C3水平呈负相关(r=-0.458,P＜0.01).尿MCP-1水平与全身SLEDAI评分、肾外SLEDAI评分、肾SLEDAI评分、血清抗dsDNA抗体、尿蛋白定量(24 h)、血肌酐水平均呈正相关(rs=0.448、0.429、0.459、0.412、0.375和0.419,P均＜0.05).尿MCP-1水平与慢性指数呈正相关(r=0.689,P＜0.01).③6例狼疮肾炎尿中可检测到TWEAK.结论 尿NGAL和MCP-1水平升高提示肾脏慢性损伤.血NGAL和血、尿MCP-1水平在狼疮肾炎活动时均明显升高,可用于监测狼疮肾炎病情活动.TWEAK临床意义需要进一步研究.     

Suppression of macrophage interleukin-12 and tumour necrosis factor-α production in mice infected with Toxocara canis

Toxocara canis induces a predominantly Th2 type response with enhanced amounts of interleukin (IL)-4 and reduced amounts of interferon (IFN)-gamma in infected mice. In this study, we investigated the macrophage function of T. canis-infected mice from the standpoint of cytokine production. C3H/HeN mice were infected with T. canis by oral administration of embryonated eggs. Ten days after infection, macrophages were obtained from spleen and peritoneal cavity, were cultured with lipopolysaccharide, and cytokines in the culture supernatant were evaluated with enzyme-linked immunosorbent assay. Macrophages from T. canis-infected mice produced IL-1 and IL-6 equivalent to macrophages from normal mice. The production of IL-10 and tumour growth factor (TGF)-beta was enhanced, but IL-12 and tumour necrosis factor (TNF)-alpha production was diminished. The addition of IFN-gamma, anti-IL-10 antibody, anti-TGF-beta antibody or indomethacin did not restore the production of IL-12 and TNF-alpha by macrophages from T. canis-infected mice. Furthermore, the stimulation of normal macrophages with T. canis antigen in vitro induced IL-1alpha, IL-6, IL-10 and TGF-beta, but not IL-12 and TNF-alpha. These results indicate that cytokine producing pattern of macrophages is altered by T. canis-infection, and this altered macrophage function may play an important role in the modification of the immune response to T. canis.     

Mucosal concentrations of interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor-α in pelvic ileal pouches

Concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) were determined by solid-phase ELISA in tissue homogenates of mucosal biopsy specimens obtained from pelvic ileal pouches in 13 patients with pouchitis (reservoir ileitis) and 17 with pouches without pouchitis. Normal ileal mucosa was used as a control. IL-1β was detected in all tissue homogenates from patients with pouchitis compared with only 29% from pouches without pouchitis and none from controls. IL-6 and IL-8 were present in all pouchitis specimens, in 70% of the specimens from nonpouchitis and only 30% of specimens from controls. TNF-α was undetectable in all specimens examined. The concentrations of IL-1β, IL-6, and IL-8 were significantly greater (P<0.001) in biopsy specimens from pouchitis compared to those from pouches without pouchitis or normal ileal mucosa and in patients with pouchitis tissue levels of IL-1β significantly correlated with IL-6 (P<0.05) and IL-8 (P<0.01). Furthermore IL-1 and IL-8 levels were significantly higher in tissue specimens from nonpouchitis pouches than in those from normal ileal mucosa (P<0.02). These results suggest that an enhanced cellular immunity operatesin vivo at the mucosal level in pouchitis as in the case of ulcerative colitis.     

尿中性粒细胞明胶酶相关脂质运载蛋白和白细胞介素-18对重症患者急性肾损伤的早期诊断价值

目的 探讨尿中性粒细胞明胶酶相关脂质运载蛋白(uNGAL)和尿IL-18(uIL-18)对重症患者急性肾损伤(AKI)的早期诊断价值.方法 以我院ICU收治的92例危重症患者为观察对象,将1周内符合RIFLE诊断标准的AKI患者纳入AKI组(46例),对照组(46例)由匹配的非AKI患者构成.每日收集尿标本,持续1周.ELISA检测uNGAL和uIL-18水平.用受试者工作特征曲线(ROC)评价uNGAL、uIL-18和血肌酐(SCr)对AKI的诊断作用.结果 与AKI诊断前3天比较,AKI诊断前2天患者uNGAL明显增高(P<0.05),但uIL-18和SCr无明显改变(P值均>0.05);AKI诊断前1天AKI患者uNGAL和uIL-18明显增高(P值均<0.05),但SCr无明显改变(P>0.05);观察期间对照组uNGAL、uIL-18和SCr均无明显变化(P值均>0.05).AKI诊断前3天uNGAL、uIL-18和SCr对AKI均无诊断作用;AKI诊断前2天uNGAL的ROC曲线下面积为0.840(95%CI 0.672～1.009,P<0.05),对AKI具有诊断作用,而uIL-18和SCr均无诊断作用;AKI诊断前1天uNGAL和uIL-18的ROC曲线下面积分别为0.830(95%CI 0.711～0.950,P<0.05)和0.818(95%CI 0.697～0.938,P<0.05),对AKI具有诊断作用,而SCr无诊断作用.结论 uNGAL和uIL-18对重症患者AKI可能具有早期诊断价值.     

Moxibustion inhibits interleukin-12 and tumor necrosis factor alpha and modulates intestinal flora in rat with ulcerative colitis

AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC).METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons.RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12).CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.     

Circulating tumor necrosis factor, interleukin-1 and interleukin-6 concentrations in chronic alcoholic patients

Although altered cytokine homeostasis has been implicated in the pathogenesis of alcoholic liver disease, the relationship between cytokines and metabolic consequences of alcoholic liver disease is unknown. We, therefore, sought to correlate circulating concentrations of tumor necrosis factor-alpha, interleukin-1 and interleukin-6 to clinical and biochemical parameters of liver disease in chronic alcoholic patients. We used an enzyme-linked immunosorbent assay to measure plasma tumor necrosis factor and interleukin-1 and a bioassay to measure serum interleukin-6 in three groups of alcoholic men as follows: (a) actively drinking alcoholic men without evidence of chronic liver disease, (b) nondrinking alcoholic men with stable cirrhosis and (c) patients with acute alcoholic hepatitis. Mean cytokine concentrations were elevated in cirrhotic patients and alcoholic hepatitis patients compared with controls and alcoholic patients without liver disease. Tumor necrosis factor-alpha and interleukin-1 alpha concentrations remained elevated for up to 6 mo after diagnosis of alcoholic hepatitis, whereas interleukin-6 normalized in parallel with clinical recovery. Concentrations of all three cytokines were correlated with biochemical parameters of liver injury and hepatic protein synthesis plus serum immunoglobulin concentrations. We could not demonstrate a relationship between cytokine concentrations and peripheral endotoxemia. Percentages of peripheral blood monocytes that reacted with monoclonal antibodies to CD25 (interleukin-2 receptor) and human lymphocyte antigen-DR were similar for alcoholic patients and controls. These data suggest that tumor necrosis factor-alpha and interleukin-1 alpha are related to some of the metabolic consequences of both acute and chronic alcohol-induced liver disease, whereas interleukin-6 is related to abnormalities seen in acute liver injury.     

Comparison of fecal granulocyte excretion in ulcerative colitis and Crohn's colitis

Impaired granulocyte migration has been suggested to be present in Crohn's disease on the basis ofin vitro granulocyte function tests andin vivo skin window studies. This idea is supported by the impression histologically that the acute inflammatory infiltrate in diseased bowel is less in Crohn's disease than ulcerative colitis. We have developed a method of quantitating the acute inflammatory infiltrate in inflamed bowel by measuring fecal indium-111 granulocyte excretion and have compared this assessment in patients with ulcerative colitis and Crohn's colitis matched for disease activity. For equivalent disease groups in ulcerative colitis and Crohn's colitis, there was no significant difference between fecal granulocyte excretion. These findings provide no support for the contention that there is a reduced granulocyte infiltration in Crohn's disease.     

Increased mucosal concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), sE-selectin,and interleukin-8 in active ulcerative colitis

Cell surface adhesion molecules (CAM) are important promotors of the immunoinflammatory cascade. The circulating levels of soluble intercellular adhesion molecule 1 (ICAM-1) have previously been shown to correlate with disease activity in inflammatory bowel disease. The primary aim of this study was consequently to investigate if this also applies to mucosal levels of soluble ICAM-1. We measured soluble ICAM-1 levels in intestinal biopsy specimens and the endoscopic activity of 69 patients with ulcerative colitis (UC) and 14 controls and found that the median concentration of soluble ICAM-1 was significantly higher in patients with moderately or very active UC (15.0 ng/ml) as compared to slightly active (9.8 ng/ml) and inactive UC (9.5 ng/ml) as well as controls (6.5 ng/ml) (P<0.005). To further elucidate the interactions, two other CAM [E-selectin and vascular cellular adhesion molecule 1 (VCAM-1)], together with interleukin-8 (IL-8), IL-2 receptor (IL-2R)α andβ chains, were also measured. A significant trend towards higher soluble E-selectin levels in biopsies with active UC (1.8 pg/ml) as compared to inactive UC (1.3 pg/ml) and to controls (<1.0 pg/ml) (P<0.01) was also found. In contrast, soluble VCAM-1 was barely detectable in biopsies from two UC patients. A significant correlation was found between soluble ICAM-1 and IL-8 concentrations (r=0.46;P<0.0001), and between sICAM-1 and sIL-2Rα concentrations (r=0.69;P<0.0001), while sIL-2Rβ was not detected. This study shows that intestinal ICAM-1 and E-selectin correlate with endoscopic activity of UC and with IL-8 and IL-2Rα levels. These mediators may be useful in monitoring mucosal inflammation in studies exploring the therapeutical potential of targeting CAM. The lack of detectable VCAM-1, which is induced only in venous endothelium is interesting. It may suggest that intestinal inflammation mainly affects arterial endothelial cells and support the theory that intestinal vasculitis is involved in the pathogenesis of inflammatory bowel disease.     

Local release of human neutrophil lipocalin (HNL), IL-8, and TNF-alpha is decreased as response to topical prednisolone treatment in distal ulcerative colitis and proctitis

The local release of human neutrophil lipocalin, considered to be highly specific for neutrophil granulocyte activation, and interleukin-8 and tumor necrosis factor- were studied in 11 patients with distal ulcerative colitis and proctitis before and during treatment with steroid enemas. A rectal perfusion technique for sampling and specific immunoassays for analysis were used. In responders (N = 8) the concentrations of all proteins decreased during the study. There was a close correlation between human neutrophil lipocalin concentrations and treatment response. Tumor necrosis factor- showed an initial decline in concentrations irrespective of treatment outcome and preceded the decline of human neutrophil lipocalin and interleukin-8. We conclude that decreased neutrophil degranulation is correlated with treatment outcome. Furthermore, an important role of tumor necrosis factor- in the process of stimulating neutrophil activation and degranulation in ulcerative colitis is suggested.     

2型糖尿病肾病患者血清中性粒细胞明胶酶相关脂质运载蛋白检测及意义的观察

目的探讨DN患者血清中性粒细胞明胶酶相关脂质运载蛋白(NGAL)的变化及临床意义。方法应用ELISA法检测血清NGAL水平,同时测BMI、FPG、HbA1c、高敏C反应蛋白(hs-CRP)、血脂及UAER,比较各组间的差异。结果 T2DM各组血清NGAL水平均较NC组明显升高(P<0.01)。相关分析显示,血清NGAL水平与Cr、UAER、hs-CRP、TC、HDL-C呈正相关,r分别为0.664、0.877、0.726、0.300、0.578,P<0.01;与FPG呈正相关,r为0.180,P<0.05;与HbA1c呈负相关,r为-0.172,P<0.01。多元逐步回归分析显示,与血清NGAL水平密切相关的因素为UAER、hs-CRP。结论 DN患者血清NGAL水平明显升高,且血清NGAL水平与UAER、hs-CRP密切相关。提示NGAL与早期肾损害程度相关。     

Increased interleukin-8 (IL-8) in rectal dialysate from patients with ulcerative colitis: evidence for a biological role for IL-8 in inflammation of the colon

OBJECTIVE: Infiltration of neutrophils and their release of toxic reactive oxygen species (ROS) in the colonic mucosa are associated with tissue damage in ulcerative colitis (UC). This neutrophil migration may be induced by chemoattractants, such as cytokines, in the colonic milieu. One such chemoattractant is interleukin-8 (IL-8), a neutrophil chemokine that is present at high concentrations in inflamed mucosa. However, the functional significance of IL-8 in neutrophil attraction and activation in UC has not been established. We hypothesized that IL-8 in the colonic lumen of patients with UC primes neutrophils, leading to their attraction and activation. METHODS: The colonic milieu was sampled by rectal dialysis. Using a semi-permeable membrane with a molecular weight cut-off of 12 kDa, dialysis solution was placed in the rectum and allowed to equilibrate over a 4-h period with the colonic milieu of controls or of patients with UC. IL-8 concentrations were measured by ELISA. Two functions of healthy neutrophils (PMN) were measured: expression of CD11-b surface adhesion molecules (by flow cytometry), and production of ROS (by both chemiluminescence and cytochrome C reduction assays). Neutrophil functions after exposure to rectal dialysates or n-formyl-methionyl-leucyl-phenylalanine (fMLP) were assessed before and after adding anti-IL-8 antibody or the fMLP blocker BMLP. RESULTS: IL-8 concentrations in dialysates from patients with active UC were significantly higher than in controls and correlated with disease activity. UC dialysates significantly increased ROS production and CD11-b expression by neutrophils and anti-IL-8 antibody partially (50%) inhibited these stimulatory effects of UC dialysates. Preincubation of neutrophils with UC dialysates significantly potentiated the fMLP-induced rise in ROS and anti-IL-8 antibody completely abolished this priming effect. CONCLUSIONS: The colonic milieu, sampled by rectal dialysis, from patients with active UC can both activate and prime neutrophils in vitro. High concentrations of IL-8 in the colonic lumen of UC patients are partially responsible for the activating effects of rectal dialysates, and account for all of its priming effects. These findings provide direct evidence for a role for IL-8 in inflammatory bowel disease.     

Human cobalamin deficiency: alterations in serum tumour necrosis factor-α and epidermal growth factor

OBJECTIVES: We have previously demonstrated that vitamin B12 (cobalamin)-deficient central neuropathy in the rat is associated with local overexpression of neurotoxic tumour necrosis factor (TNF)-alpha combined with locally decreased synthesis of neurotrophic epidermal growth factor (EGF). The aims of this study were to investigate whether a similar imbalance also occurs in the serum of adult patients with clinically confirmed cobalamin deficiency and whether it can be corrected by vitamin B12 replacement therapy. PATIENTS AND METHODS: We studied 34 adult patients with severe cobalamin deficiency, 12 patients with pure iron deficiency anaemia and 34 control subjects. Haematological markers of cobalamin deficiency and serum TNF-alpha and EGF levels were measured using commercial kits. Thirteen cobalamin-deficient patients were re-evaluated after 3 and 6 months of parenteral vitamin B12 treatment. RESULTS: TNF-alpha was significantly higher (p < 0.01) and EGF significantly lower (p < 0.01) in the patients with cobalamin deficiency, but both were unchanged in patients with pure iron deficiency anaemia. In cobalamin-deficient patients the serum TNF-alpha levels correlated significantly with plasma total homocysteine levels (r = 0.425; p < 0.02). In the treated patients TNF-alpha and EGF levels normalised concomitantly with clinical and haematological disease remission. CONCLUSIONS: In humans, as in rats, cobalamin concentration appears to be correlated with the synthesis and release of TNF-alpha and EGF in a reciprocal manner, because cobalamin deficiency is accompanied by overproduction of TNF-alpha and underproduction of EGF.