The relationship between adiponectin levels and proinflammatory cytokines and left ventricular mass in dialysis patients.

INTRODUCTION: Adiponectin is increased in end-stage renal disease. However, efforts to clarify the cause of that increase and its clinical effects have been inconclusive. The aim of this study was to compare serum adiponectin levels of dialysis patients against healthy individuals and evaluate the relationship among adiponectin levels, IL-6, TNF- alpha and left ventricular mass index (LVMI). METHODS: Adiponectin, IL-6 and TNF- alpha measurements and echocardiographic evaluations were performed in 36 hemodialysis, 30 continuous ambulatory peritoneal dialysis (CAPD) patients and 22 healthy volunteers. Adiponectin, IL-6 and TNF- alpha levels were measured by ELISA. RESULTS: Adiponectin was found to be higher in hemodialysis (52.78+/-18.01 ng/mL) and CAPD (52.96+/-17.53 ng/mL) groups than controls (28.36+/-13.20 ng/ mL; p=0.0003, p=0.0003, respectively). No difference was observed between the hemodialysis and CAPD groups. Adiponectin was positively correlated with IL-6 (r=0.293, p=0.02), TNF- alpha (r=0.458, p=0.0003) and LVMI (r=0.283, p=0.02). In the partial correlation analysis, by controlling for body mass index, the correlation between adiponectin and TNF- alpha (r=0.466, p=0.0003) persisted. When IL-6 was controlled with TNF- alpha, the relation between adiponectin and LVMI disappeared (r=0.145, p=0.30). In the linear regression analysis, with adiponectin as the dependent variable, and IL-6, TNF- alpha and body mass index as independent variables, a significant relationship was found between adiponectin and TNF- alpha (beta=0.488, p=0.001). CONCLUSIONS: Increased adiponectin seems to be associated with increased proinflammatory cytokines in dialysis patients, and this relationship suggests adiponectin may have a role in the development of left ventricular hypertrophy.

Effect of oophorectomy and exogenous estrogen replacement on liver injury in experimental obstructive jaundice.

AIM: To investigate the role of estrogen on liver injury in an experimental obstructive jaundice model. METHODS: Three groups of female rats were constituted; group 1 was oophorectomized and given E2 (n = 14), group 2 was oophorectomized and given placebo (n = 14), and group 3 was sham operated (n = 14). Fourteen days following constitution of bile duct ligation, all groups were compared in terms of serum tests, histopathologic parameters, and tissue levels of IFN-gamma and IL-6. RESULTS: The parameters representing both the injury and/or the reactive response and healing were more pronounced in groups 1 and 2 (c2 = 17.2, c2 = 10.20; c2 = 12.4, P < 0.05). In the sham operated or E2 administered groups significantly lower tissue levels of IFN-gamma and higher IL-6 levels were found. In contrast, high IFN-gamma and low IL-6 tissue levels were found in the oophorectomized and placebo group (P < 0.001). Kupffer cell alterations were observed to be more pronounced in the groups 1 and 3 (c2 = 6.13, P < 0.05). CONCLUSION: Our study indicates that E2 impaired liver functions, accelerated both the liver damage and healing. In the conditions of bile duct obstruction, estrogen significantly changed the cytokine milieu in the liver.

Determinants of protection against diphtheria in adult hemodialysis patients.

Diphtheria is of great epidemiological concern. Although mainly observed during childhood, unvaccinated adults and relatively immunocompromised patients are at increased risk for acquiring diphtheria. We aimed to determine the rates and certain determinants of protection against diphtheria in adult hemodialysis (HD) patients. Protection rates of 322 HD patients were compared with 65 diabetes mellitus type 2 (DM) patients and 65 healthy controls. A questionnaire was held in regard to smoking habits and alcohol intake. Antibody levels against diphtheria were assessed by an in-house ELISA and a concentration of >or=0.1 IU/mL was regarded as protective. Effects of age, gender and time being on dialysis on protection were assessed by logistic regression. Ratios of individuals with protective antibody levels were found to be 36% (116/322), 27.7% (18/65), and 52.3% (34/65) for HD, DM, and control groups, respectively. Hemodialysis patients had a significantly (p < 0.05) lower protection rate than healthy controls. In all study groups, there was a tendency of higher protection rate with increasing age. These low ratios of protected individuals in both HD and DM patient groups are alarming, as these patients generally have defects in vaccine responses, and carriage is important in the perpetuation of diphtheria. The protection status of these patient groups might be improved with additional vaccinations.

Investigation of the functional characteristics of antibodies to therapeutic anti-human tumor necrosis factor alpha monoclonal antibody.

Humanized antibody-based treatment modalities represent an active area of investigation. Included in these strategies are passive administrations of monoclonal antibodies, which recognize tumor necrosis factor alpha (TNF-alpha). However, several problems associated with these types of treatment strategies have been reported in the literature. We attempted to address the issue related to unresponsiveness to infliximab that might be induced by anti-idiotype response to the passively administered humanized monoclonal antibody. The characteristics and functional importance of antibodies to infliximab (ATI) were investigated in human sera. We studied the binding characteristics of ATI to infliximab, TNF-alpha Receptor-I (RI, p55) and Receptor-II (RII, p75). In addition, cytotoxicity effect on L929 cells and blocking effects on the binding of TNF-alpha with infliximab and etanercept were also analyzed. On the basis of the results obtained from the experiments, it seems that the target epitope for ATI is related with somewhere else not residing in the region capable of generating "mirror image". The results presented indicate that ATI does not mimic the functional characteristics of TNF-alpha. However, ATI inhibited the binding properties of infliximab to TNF-alpha.

A novel mutation in the vascular Ehlers-Danlos syndrome: a case presenting with colonic perforations.

A 15-year-old girl who had chronic constipation presented with peritonitis caused by sigmoid colon perforation. After her sigmoid colon was resected and an end colostomy performed, as there were no apparent causes for perforation, she was followed-up. After the second colonic perforation proximal to the end colostomy, as the pathologic findings revealed myopathic changes, the connective tissue disorders were evaluated. Her molecular biology studies revealed an undefined missense mutation in the COL3A1 gene, confirming the diagnosis of vascular Ehlers-Danlos syndrome (EDS). As she refused a permanent stoma, total colectomy and ileorectal anastomosis were performed, but the postoperative complications resulted in a fatal progression. The typical progression of vascular EDS will be discussed with the presented case by means of a review of the English medical literature on children diagnosed with vascular EDS.

A new efficient method for eliminating the interference effect of human serum and increasing the sensitivity and recovery rate of enzyme immunoassay.

A new, very simple method for increasing the sensitivity and recovery rate of enzyme-linked immunosorbent assay (ELISA) for the precise quantification of antigen in human serum is described. The assay design uses CATNF6A4c IgG2a monoclonal antibody and biotinylated anti-human tumor necrosis factor-alpha (hTNF-alpha) polyclonal mouse IgG as the capture and tracer antibodies, respectively. The assay is completed within 4 hours at room temperature and is capable of detecting both recombinant and native human TNF-alpha. The assay incorporates the use of saturated ammonium sulfate (SAS) as a component of the dilution buffer to amplify the resultant signal from antigen containing human serum and eliminating the endogenous interference of native human serum. SAS worked optimally at the final concentrations, ranging from 1.2% to 11%. The addition of SAS to the dilution buffer resulted in a dramatic increase in both sensitivity and recovery rate of the ELISA. The results demonstrated that 50 microL of dilution buffer, containing SAS, enabled the precise quantification of human TNF-alpha in 100 microL of human serum samples and eliminated the interference of native serum, which seemed to be related to complement proteins. Therefore, dilution buffer containing SAS, at a defined concentration, seemed to be a potential candidate for resolving sensitivity and recovery problems usually encountered in immunoassays when measurement was performed with native serum samples. The proposed technique provides an easy, practical, and consistent method for ELISA when using human native serum.

Effect of mucosal immunomodulation with fed cholera toxin on healing of experimental colonic anastomosis.

PURPOSE: The aim of this study was to investigate in rats whether preoperative orogastric administration of low doses of cholera toxin would influence the mechanical strength of experimental colonic anastomosis on the basis of the gut mucosal immunomodulation effect of this antigen. METHODS: The cholera toxin group (n = 14) was fed 10 microg of cholera toxin in phosphate-buffered saline three times before surgery at 10-day intervals, whereas the controls (n = 14) received phosphate-buffered saline only. Twenty-four hours after the last dose of cholera toxin (or placebo in control group), the animals underwent left colonic transection and anastomosis. Seven days after colonic transection-anastomosis, the bursting pressure of the anastomotic segment was recorded in situ. Perianastomotic and extra-anastomotic tissue samples were obtained for measurements of tissue transforming growth factor-beta, interleukin-6, and interferon-gamma levels with enzyme-linked immunosorbent assay. RESULTS: Cholera toxin administration resulted in a significantly higher bursting pressure than in the control group (165.78 +/- 12.37 vs. 138.4 +/- 7.87 mmHg; P < 0.001). Compared with the control group, the heightened mechanical strength of colonic anastomosis provided by cholera toxin was associated with significant increases in the perianastomotic tissue levels of transforming growth factor-beta (199.34 +/- 24.85 vs. 70.66 +/- 10.63 pg/ml; P < 0.001) and interleukin-6 (439.31 +/- 95.14 vs. 289.57 +/- 96.59 pg/ml; P = 0.001), whereas interferon-gamma was significantly lower (174.04 +/- 44.82 vs. 219.00 +/- 31.35 pg/ml; P < 0.05). This cytokine pattern induced by cholera toxin in the wound milieu was also found to be similar in the extra-anastomotic colon. CONCLUSION: The mechanical strength of uncomplicated experimental colonic anastomosis increased significantly with gut mucosal immunomodulation with repeated low preoperative doses of cholera toxin. This enhanced healing had significant positive correlation with the colonic tissue level of transforming growth factor-beta and inverse correlation with interferon-gamma. If the relevant dose regimen is identified and its safety is assured in humans, gut mucosal immunomodulation might provide an efficient, safe, and inexpensive tool to improve surgical outcome in colorectal surgery, particularly in high-risk situations.