Adenosine deaminase activity in patients with Crohn's disease: distinction between active and nonactive disease.

BACKGROUND: Crohn's disease (CD) is a common chronic inflammatory bowel disease. During the disease a cascade of immunologic events occur including mucosal influx of inflammatory cells like neutrophils. Adenosine deaminase (ADA) is important in inflammatory responses and serves as a marker of activated leukocytes. MATERIALS AND METHODS: In this study, we investigated the activity of total ADA (tADA) and its isoenzymes, ADA1 and ADA2, in serum and neutrophils derived from 20 active patients with CD, 20 patients in remission, as well as in 15 healthy controls. RESULTS: Patients with active disease had significantly (P<0.001) higher levels of tADA in serum (22.9±4.9 U/l) than patients in remission or healthy controls (14.0±3.4 U/l and 13.2±2.4 U/l respectively). ADA2, the main isoenzyme in the serum was higher in active patients by 60% as compared with patients in remission and healthy controls (19.7±1.9 U/l, 12.3±1.2 U/l, and 12.2±0.9 U/l respectively). We did not find a significant difference in these parameters between healthy controls and stable patients. There was a positive correlation (R=0.516) between tADA activity and C-reactive protein levels in patients with CD. Enhanced activity in tADA was also detected in neutrophils that were obtained from all patients with CD as compared with healthy controls (15.3±2.9 U/g, 14.1±2.3 U/g, and 9.4±2.9 U/g protein, respectively). This is mainly due to a significant increment (up to 51%) in ADA1 activity, the main isoenzyme in the neutrophils (84% out of the tADA). The cause of this increment remains to be elucidated. CONCLUSION: The results obtained in this study demonstrated elevated levels of tADA and ADA2 in patients with active disease. As the patient improves and becomes clinically stable these levels decrease, approaching normal values. tADA and ADA2 can be used as markers of inflammation, and provide a supportive indicator of CD activity.

C reactive protein (CRP) as a predictor for true bacteremia in children.

BACKGROUND: Despite the recent advances in methods for culturing bacteria, at least 24 hours are needed for most pathogens to be recognized. This period may be critical for the differentiation of a true bacteremia from a contaminated culture. We studied the value of CRP compared to total leukocytes (WBC) and absolute neutrophil count (ANC) in differentiating positive, contaminated and negative blood cultures in various pediatric infectious diseases (pneumonia, acute gastroenteritis (AGE), urinary tract infection (UTI) and acute otitis media (AOM)). MATERIAL/METHODS: Data was collected retrospectively from patients who were admitted or discharged from to the pediatric ward with one of the above diagnoses. Children with chronic diseases or with immunodeficiency were excluded from the study. RESULTS: CRP levels were significantly higher in the positive culture group versus contaminated and negative groups (101 mg/L, 30.9 mg/L, 34.3 mg/L, respectively). The total leukocytes and ANC were not of value. When divided into diagnostic subgroups, CRP levels were significantly higher in the positive blood culture groups in patients with pneumonia and AGE. The sensitivity of a CRP value above 85 mg/L for pneumonia and UTI and above 30 mg/L for AGE and AOM in discriminating true positive versus contaminated culture was 70% with a specificity of 67.6% and a positive predictive value of 60.3%. CONCLUSIONS: CRP may be used for differentiation between positive and contaminated blood cultures in children and have been shown to be a better predictor than WBC or ANC for this purpose.

Oxidative stress, inflammation and neutrophil superoxide release in patients with Crohn's disease: distinction between active and non-active disease.

Increased oxidative stress has been previously demonstrated in patients with Crohn's disease (CD). However, to date, this parameter has not been assessed in a comparative study of patients in prolonged remission and those with the active disease. We report here our study of lipid peroxidation, antioxidant and inflammation status in serum derived from 16 active CD patients, 27 clinically stable patients, and 15 healthy controls. Results The extent of lipid peroxidation was higher in CD patients than in the healthy controls, while the levels of lipid peroxides (PD) and of thiobarbituric acid-reactive substances (TBARS) were significantly (P < 0.01) higher in serum obtained from patients with active CD (22 and 30%, respectively) than in that obtained from patients in remission. An analysis of the antioxidant status revealed that the beta-carotene levels in sera derived from all CD patients - patients with active or stable CD (49.4 +/- 15 and 95.6 +/- 25 mg% beta-carotene, respectively) - were higher than that in the controls (145 +/- 40 mg%). Serum activity of glutathione peroxidase (GSH-Px) was significantly (P < 0.001) higher (by 31%) in the patients with active CD than in the control group. There was no significant difference in GSH-Px activity between patients in remission and the controls. In terms of the inflammatory status, we found significantly (P < 0.01) higher levels of C-reactive proteins (CRP) and of tumor necrosis factor alpha (TNFalpha) in patients with active CD than in CD patients in remission. There was a significant correlation between those parameters and the extent of lipid oxidation. Neutrophils, which are a potential source of oxygen-free radicals, were activated by incubation with phorbol myristate acetate (PMA). Superoxide and lysozyme release were significantly reduced in neutrophils derived from patients with active CD (by 25 and 28%, respectively) in comparison to the control group. However, stimulated neutrophils from stable patients demonstrated only a minimally non-significant lower release of superoxide and lysozyme compared to the controls. Conclusion The results obtained in this study demonstrate an enhanced inflammatory and oxidative stress and a decreased antioxidant status in patients with active CD. As the patients improved and became clinically stable, the oxidative parameters decreased, approaching normal values. As neutrophil activation was also lower in patients with active disease, neutrophil activation may represent a possible defense mechanism of the body against tissue injury.

Paraoxonase activity following exercise-based cardiac rehabilitation program.

PURPOSE: The effect of gender on paraoxonase activity was determined in 37 ischemic heart disease patients who underwent a 12-week aerobic exercise training program. METHODS: Paraoxonase activity was measured by its arylesterase activity (spectrophotometrically, at 250 degrees C, wavelength 270 nm). RESULTS: A 16.7% increase in paraoxonase activity was found following the 12-week exercise program. In addition, there was a significant gender effect with higher mean paraoxonase levels among women during both preexercise (20.8%) and postexercise (24.2%) testing. CONCLUSIONS: Aerobic exercise training was found to be an effective means in inducing plasma levels elevation of the antioxidative, antiatherogenic paraoxonase in patients with coronary artery disease, and particularly in female patients.

The early anti-oxidant effect of carvedilol predicts the clinical course in congestive heart failure patients.

BACKGROUND: Carvedilol, a beta1 and beta2 as well as an alpha1 adrenoreceptor antagonist with multiple hemodynamic, anti-ischemic and anti-oxidant properties, is widely accepted for the treatment of hypertension and congestive heart failure (CHF). It has been shown to improve morbidity and mortality in CHF. OBJECTIVES: To assess whether the anti-oxidant effect of carvedilol has an impact on the clinical course in post-myocardial infarction (MI) CHF. METHODS: Thirty-nine recent MI patients, aged 60.5 +/- 7 years, New York Heart Association functional class (FC) II-III, and left ventricular ejection fraction (LVEF) 29 +/- 3.8%, underwent oxygen free radical (OFR) assessment using the thiobarbituric acid reactive substances, thermochemoluminescence and conjugated dienes methods. OFR was determined at baseline, 1, 3, 12, and 24 h after 3.125, 6.25 and 12.5 mg carvedilol, and after 6 months of treatment. Brain natriuretic peptide (BNP), LVEF, FC change, 6-min walk test (6MW) and quality of life scores were evaluated before and after 6 months. RESULTS: Two patterns of OFR activity were found. In 29 patients (group 1) a significant and consistent reduction in OFR following administration of each dose of carvedilol was found, significantly correlating with each of the outcome parameters. In ten patients (group 2), no change in OFR was found, nor in any of the other outcomes. At 6 months, FC improved in 23 patients from group 1 (79.3%) and only in one (10%) from group 2 (P<0.01). 6MW increased by more than 10% in group 1 with no change in group 2 (P<0.05). BNP decreased from 397 +/- 36 pg/ml to 171 +/- 15.9 pg/ml (P<0.01) in group 1 compared to 381 +/- 32.5 pg/ml and 405 +/- 36 pg/ml, respectively (P=not significant) in group 2. One year hospital admissions and death rate were significantly higher in group 2. CONCLUSIONS: The early anti-oxidative effect of carvedilol correlates well with the clinical course and probably predicts it.

Enhanced oxidative stress and leucocyte activation in neoplastic tissues of the colon.

Excess of intracellular reactive oxygen species results in an environment that may modulate gene expression, or damage cellular molecules. These events are assumed to contribute to the process of carcinogenesis. In the present study, we measured the extent of lipid peroxidation and antioxidative status in colonic tumors and normal colonic mucosa obtained from 25 patients with colorectal carcinoma. Levels of lipid peroxides (PD) and of thiobarbituric acid reactive substances (TBARS) were significantly increased, by 54 and 59%, respectively, in tissue specimens obtained from the colonic tumor as compared with normal colonic mucosa (PD, 2.78+/-0.31 versus 1.81+/-0.29 nmol/mg tissue, TBARS, 0.86+/-0.1 versus 0.54+/-0.08 nmol/mg tissue). Activities of the antioxidant enzymes catalase and glutathione peroxidase (GPx) were also higher (by 67 and 29%, respectively) than in normal mucosa, probably in response to the increased free radical stress occurring in cancerous tissues. Myeloperoxidase (MPO) and adenosine deaminase (ADA) are markers of activated leukocytes and are related to the production of oxygen free radicals by these cells. Their activities were significantly elevated in the neoplastic tissue as compared to the normal tissue (MPO, 7.4+/-1.5 versus 4.1+/-0.95 U/mg tissue, ADA, 4.17+/-0.65 versus 2.99+/-0.80 U/g tissue), suggesting a possible involvement of activated leukocytes in the enhanced oxidative stress in the cancerous tissue. Our results demonstrate an enhanced oxidative stress in the neoplastic tissue. Leukocyte activation was also higher in the carcinogenic tissue, indicating a possible contribution of these cells to a further oxidative stress-derived tissue injury. These observations add to previous studies and may encourage therapeutic trials with antioxidants as a means of preventing colorectal cancer and preventing further tissue injury in the neoplastic tissue and its surroundings.

Iron status and neurobehavioral development of premature infants.

OBJECTIVE: This study was conducted to examine the relation between iron status and neurobehavioral development in premature infants. STUDY DESIGN: Infants born before 34 weeks postmenstrual age and who were medically stable were studied. Anemia was defined as hemoglobin < or =10 g/Dl and low iron stores as a serum ferritin concentration < or =75 microg/l. The infants were classified as anemic with low ferritin (Group 1; n=18), anemic with normal ferritin (Group 2; n=14), and nonanemic with normal ferritin (Group 3; n=21). A total of 18 reflexes were behaviorally evaluated at 37 weeks postmenstrual age and "reflex scores" were compared between the groups. Higher scores reflect a greater percentage of abnormal reflexes. RESULTS: Infants in group 1 (anemia/low ferritin) had a significantly higher reflex score (51.45+/-18.32%) than infants in Group 3 (38.32+/-17.75%). Group 2 had an intermediate score (45.40+/-21.70%), but not different from the other two groups. CONCLUSION: These data indicate that low iron status, both measured by anemia and ferritin levels, is related to poorer neurobehavioral status in premature infants.

Leptin and cytokines levels in children with failure to thrive.

BACKGROUND: The majority of cases of failure to thrive (FTT) are non-organic. Many of these patients present with significant decreased caloric intake. It appears as if the appetite regulation center in the hypothalamus is not attuned to the calorie requirements of the infant. OBJECTIVE: Our hypothesis was that some cases of non-organic FTT might be caused by abnormalities in hunger/satiety control secondary to neuroendocrine or cytokine imbalance. The aim of this study was to investigate which hormonal/cytokine profiles could be assigned to a defined category of FTT, namely organic, psychosocial and idiopathic subgroups. STUDY DESIGN: 34 patients were enrolled and 32 completed the study (12 controls, 12 idiopathic FTT, 5 organic FTT, and 3 psychosocial FTT). Each child was assessed by a pediatric gastroenterologist, dietician, and social worker and underwent appropriate laboratory investigation during which leptin, IL1, IL6 and TNF-alpha levels were determined. The Mann-Whitney U test was used to compare the groups. RESULTS: IL6 was the only cytokine that showed significant differences between FTT patients (4.06 +/- 6.3 pg/ml) and normal controls (0.0 pg/ml (p = 0.028). Leptin values were significantly higher in the normal control group (1632 +/- 483 pg/ml) as compared to FTT patients (685 +/- 687 pg/ml) (p = 0.001). CONCLUSIONS: Our results indicate that leptin does not play a role in the pathogenesis of anorexia in children with FTT. It is however, possible that IL6 may be an important factor in the etiology of anorexia in patients with FTT.

Modifications and oxidation of lipids and proteins in human serum detected by thermochemiluminescence.

Detection of electronically excited species (EES) in body fluids may constitute an important diagnostic tool in various pathologies. Examples of such products are triplet excited carbonyls (TEC), which can be a source for photon emission in the 400-550 nm range. The aim of the present study was to determine the actual contribution of lipid and protein components (protein carbonyls) to photon emission generated by thermochemiluminescence (TCL) during the heating of biological fluids. In this study, a new TCL Photometer device, designed by Lumitest Ltd, Israel, was used. Samples were heated to a constant temperature of 80 +/- 0.5 degrees C for 280 s and photon emission was measured at several time points. In order to compare the results of TCL measurements to conventional methods of detecting lipid and protein oxidation, each examined sample was also heated in a waterbath at 80 degrees C for 10-280 s. Lipid and protein oxidation were subsequently measured using conventional methods. The TCL of four polyunsaturated fatty acids (PUFA) with three to six double bonds was measured. The elevation of the PUFA TCL amplitude correlated with the increase in the number of double bonds of PUFA. A correlation between the increase in TCL intensity and protein carbonyl generation in bovine serum albumin (BSA) was also observed. In the venous blood serum, our study showed that an increase of TCL intensity during heating reflected the cleavage of TEC of lipid origin. Our study suggests that biological molecules such as proteins, lipids and other molecules, which may become unstable during heating, are capable of generating EES. We demonstrated that a TCL curve can be used as a kinetic model for measuring oxidative processes, which reflects modifications of different molecules involved in the oxidative stress phenomena.