Plasma and urinary cytokine homeostasis and renal function during cardiac surgery without cardiopulmonary bypass

Cardiopulmonary bypass (CPB) significantly contributes to the plasma pro-inflammatory cytokine response at cardiac surgery. Complementary plasma and urinary anti-inflammatory cytokine responses have been described. The pro-inflammatory cytokines interleukin 8 (IL-8), tumour necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta) have lower molecular weights than the anti-inflammatory cytokines interleukin 10 (IL-10), interleukin 1 receptor antagonist (IL-1ra) and TNF soluble receptor 2 (TNFsr2) and thus undergo glomerular filtration more readily. In vitro work suggests that proximal tubular cells are vulnerable to pro-inflammatory cytokine mediated injury. Accordingly, this study investigated the hypothesis that cardiac surgery without CPB would not have significant changes in plasma and urinary cytokines and proximal renal dysfunction. Eight patients undergoing coronary artery bypass grafting (CABG) without CPB were studied. Blood and urine samples were analysed for pro- and anti-inflammatory cytokines. Proximal tubular dysfunction was measured using urinary Nu-acetyl-beta-D-glucosaminidase (NAG)/creatinine and alpha(1)-microglobulin/creatinine ratios. Plasma IL-8, IL-10, IL-1ra and TNFsr2 were significantly elevated compared with baseline. Urinary IL-1ra and TNFsr2 were significantly elevated, as were urinary NAG/creatinine and alpha(1)-microglobulin/creatinine ratios. Two hours following revascularization, urinary IL-1ra correlated with urinary alpha(1)-microglobulin/creatinine ratios (P<0.05). As previously reported in CABG surgery with CPB, we now report that non-CPB cardiac surgery also has significant changes in plasma and urinary cytokine homeostasis and early proximal tubular injury. The correlation between urinary IL-1ra and alpha(1)-microglobulin/creatinine ratios is consistent with earlier suggestions of a mechanistic link between cytokine changes and proximal tubular dysfunction. The relative roles of CPB and non-CPB processes in producing inflammation still require definition.     

Cytokine phenotype,genotype, and renal outcomes at cardiac surgery

BackgroundCardiac surgery modulates pro- and anti-inflammatory cytokine balance involving plasma tumour necrosis factor alpha (TNFα) and interleukin-10 (IL-10) together with urinary transforming growth factor beta-1 (TGFβ1), interleukin-1 receptor antagonist (IL1ra) and tumour necrosis factor soluble receptor-2 (TNFsr2). Effects on post-operative renal function are unclear. We investigated if following cardiac surgery there is a relationship between cytokine (a) phenotype and renal outcome; (b) genotype and phenotype and (c) genotype and renal outcome. Since angiotensin-2 (AG2), modulates TGFβ1 production, we determined whether angiotensin converting enzyme insertion/deletion (ACE I/D) genotype affects urinary TGFβ1 phenotype as well as renal outcome.MethodsIn 408 elective cardiac surgery patients we measured pre- and 24 h post-operative urinary TGFβ-1, IL1ra and TNFsr2 and pre- and 2 h post-operative plasma TNFα and IL-10. Post-operative responses were compared for each cytokine in patients grouped according to presence or absence of renal dysfunction defined as a drop from baseline eGFR of greater than 25% (as calculated by the method of modification of diet in renal disease (MDRD)) occurring (1) within the first 24 and (2) 48 postoperative hours (early renal dysfunction), (3) on the fifth postoperative day (late renal dysfunction) or (4) at any time throughout the 5 day postoperative period (early and late combined). Patient genotype was determined for TNF/G-308A, TGFβ1-509 C/T, IL10/G-1082A and ACE I/D.ResultsPost-operative plasma IL-10 and urinary TGFβ1 responses were significantly higher in patients who developed early renal dysfunction. IL1ra and TNFsr2 responses were significantly lower 24 h post-operatively in patients who developed late renal dysfunction. Genotype did not alter cytokine phenotype or outcome.Conclusions/inferencesCytokine profiling may help predict early and late renal dysfunction. Genotypes studied did not alter phenotype or outcome.     

Urinary aminopeptidase activities as early and predictive biomarkers of renal dysfunction in cisplatin-treated rats

This study analyzes the fluorimetric determination of alanyl- (Ala), glutamyl- (Glu), leucyl-cystinyl- (Cys) and aspartyl-aminopeptidase (AspAp) urinary enzymatic activities as early and predictive biomarkers of renal dysfunction in cisplatin-treated rats. Male Wistar rats (n = 8 each group) received a single subcutaneous injection of either saline or cisplatin 3.5 or 7 mg/kg, and urine samples were taken at 0, 1, 2, 3 and 14 days after treatment. In urine samples we determined Ala, Glu, Cys and AspAp activities, proteinuria, N-acetyl-β-D-glucosaminidase (NAG), albumin, and neutrophil gelatinase-associated lipocalin (NGAL). Plasma creatinine, creatinine clearance and renal morphological variables were measured at the end of the experiment. CysAp, NAG and albumin were increased 48 hours after treatment in the cisplatin 3.5 mg/kg treated group. At 24 hours, all urinary aminopeptidase activities and albuminuria were significantly increased in the cisplatin 7 mg/kg treated group. Aminopeptidase urinary activities correlated (p<0.011; r²>0.259) with plasma creatinine, creatinine clearance and/or kidney weight/body weight ratio at the end of the experiment and they could be considered as predictive biomarkers of renal injury severity. ROC-AUC analysis was made to study their sensitivity and specificity to distinguish between treated and untreated rats at day 1. All aminopeptidase activities showed an AUC>0.633. We conclude that Ala, Cys, Glu and AspAp enzymatic activities are early and predictive urinary biomarkers of the renal dysfunction induced by cisplatin. These determinations can be very useful in the prognostic and diagnostic of renal dysfunction in preclinical research and clinical practice.     

Environmental epidemiological study and estimation of benchmark dose for renal dysfunction in a cadmium-polluted area in China

We have performed a study aimed at investigating the critical concentration of urinary cadmium (UCd) required for the development of renal dysfunction. We studied population groups (totally 790 persons) living in two cadmium exposed areas and one control area in China. UCd, was determined as an indicator of cadmium exposure and accumulation, while the concentrations of N-acetyl-beta-D-glucosaminidase (NAG), its iso-form B (NAG-B), beta2-microglobulin (B2M), retinol binding protein (RBP), and albumin (ALB) in urine were measured as indicators of the renal effects caused by cadmium. There was a significantly increased prevalence of hyperNAGuria, hyperNAG-Buria, hyperB2Muria, hyperRBPuria and hyperALBuria with increasing levels of Cd excretion in urine. We used the benchmark dose (BMD) procedure to estimate the critical concentration of urinary cadmium in this general population. The lower confidence limit of the BMD (LBMD-05) of urinary cadmium for a 5% level of risk above the background level was estimated for each of the renal effect indicators. The BMD-05/LBMD-05 were estimated to be 4.46/3.99, 6.70/5.87, 8.36/7.31, 7.98/6.98 and 15.06/12.18 microg/g creatinine for urinary NAG-B, NAG, B2M, RBP and ALB, respectively. Our findings suggest, based on the present study, that the Lower Confidence Limit of the Population Critical Concentration of UCd (LPCCUCd-05) of tubular dysfunction for 5% excess risk level above the background may be ca. 3-4 microg/g creatinine, and that cadmium concentration in urine should be kept below this level to prevent renal tubular damage. This report is the first to use the BMD method in this field and to define the concept of critical concentration in urine.     

Urinary enzyme concentrations in the owl monkey (Aotus nancymae)

The activity of three urinary enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and N-acetyl-β-D-glucosaminidase (NAG), was evaluated in 71 adult owl monkeys. Fifty-six animals had normal renal function, while 15 had evidence of renal dysfunction. Urinary enzyme: urinary creatinine ratios (U_E:U_Cr) were also determined. The activity for NAG was similar to that of other species, while ALP and AST were higher. Regression analyses revealed that urinary enzymes and U_E:U_Cr were significantly correlated (P ≤ 0.0001) with indices of renal damage and could identify active renal disease.     

Prevalence of kidney dysfunction in humans – Relationship to cadmium dose, metallothionein, immunological and metabolic factors

Long term cadmium (Cd) exposure in occupational and general environments may give rise to kidney dysfunction. This effect is usually considered to be the critical effect, i. e. the effect that occurs at relatively low level of exposure. The present review focused on studies of the prevalence of cadmium-related kidney dysfunction among population groups residing in cadmium contaminated areas in China. Dose–response relationships were shown between UCd and the prevalence of increased levels of biomarkers in urine of renal tubular dysfunction such as urinary beta-2-microglobulin or N-acetyl-beta-d-glucosaminidase – NAG or urinary albumin, a biomarker of glomerular kidney dysfunction. Factors that influence these dose–response relationships include: 1) Metallothionein mRNA levels in peripheral blood lymphocytes, used as a biomarker of the ability of each person, to synthesize metallothionein (a protein known to provide intracellular protection against cadmium toxicity). 2) The occurrence of increased levels in blood plasma of autoantibodies against metallothionein. 3) Concomitant changes in glucose metabolism i e Type II diabetes. 4) Concomitant exposure to other nephrotoxic agents such as inorganic arsenic. Increased susceptibility in diabetics has been shown also in population groups in Europe. In persons with type II diabetes and increased levels of autoantibodies against metallothionein in blood plasma or in persons with concomitant exposure to environmental inorganic arsenic, indications of Cd-related kidney dysfunction was observed at UCd levels around 1 μg/g creatinine, levels found among “unexposed” population groups in many countries.     

Changes in urinary thromboxane level in man during cardiopulmonary bypass: effect of thromboxane on renal tubules

ONO-3708, a thromboxane A2 (TXA2) antagonist, was administered at a dose of 2 micrograms/kg/min by a double blind method as compared with inactive placebo during cardiopulmonary bypass (CPB) procedure to study the changes of thromboxane B2 (TXB2) levels in plasma and urine and N-acetyl-glucosaminidase (NAG) level in urine. TXB2 levels in plasma and urine increased significantly (P less than 0.01) during CPB in the patients given ONO-3708 (ONO-3708 group) and in those given placebo (placebo group). The plasma TXB2 level as expected from the urinary TXB2 level was higher than the measured plasma TXB2 level showing increases in TXB2 originating from the kidney. The urinary NAG level, increased significantly (P less than 0.01) during CPB the NAG level in ONO-3708 group was significantly low as compared to placebo group. The levels of TXB2 in plasma and urine in ONO-3708 group were not different from those of the patients receiving placebo, indicating that ONO-3708 does not have any effect on TXA2 production. We concluded that the elevation of urinary TXB2 level might be due to increased TXA2 production in the kidney under hypoxic condition induced by hypotension and lowered perfusion during CPB. Furthermore, the increased production of TXA2 appears to suppress the functions of the renal proximal tubules.     

坦克作业对乘员肾脏功能的影响

目的：观察坦克作业对乘员肾脏功能的影响。方法：在我军某坦克部队随机选取152名坦克乘员为观察组,在同一部队选取非坦克作业战士37名为对照组。留取24h尿和晨尿,检测尿中α1-微球蛋白（α1-MG）、β2-微球蛋白（β2-MG）、IgG、N-乙酰-β-葡萄糖苷酶（NAG）和尿微量白蛋白（UAE）排泄率。结果：与对照组比较,观察组尿α1-．MG、β2-MG、尿NAG、尿UAE均明显升高,且平均值均超过临床检验正常值,尿IgG无明显升高。其中从事坦克作业50摩托小时以上的坦克乘员尿中β2-MG、NAG、UAE均高于对照组（P〈0．05）,从事坦克作业51～100摩托小时的尿中α1-MG虽有升高,但未有统计学差异且平均值在正常范围内,从事坦克作业大于301摩托小时的坦克乘员尿中α1-MG显著高于对照组。脱离坦克作业3年后乘员尿中β2-MG、NAG、UAE降低至正常水平,但大于10年者尿中β2-MG再度出现升高,与6—10年组比较有显著差异（P〈0．05）。脱离坦克作业后坦克乘员尿中α1-MG虽有下降,但始终未降至正常水平。结论：坦克作业对乘员肾脏功能有一定影响,脱离坦克作业后乘员肾功能可得到较好的恢复,但远期仍遗留一定程度的肾小管重吸收功能障碍。     

Increased urinary zinc excretion in cancer patients is linked to immune activation and renal tubular cell dysfunction

Urinary zinc excretion is known to be increased in cancer patients, but the pathogenesis of this phenomenon remains uncertain. Both skeletal muscle catabolism and renal tubular cell dysfunction have been proposed to explain this observation. We have investigated urinary zinc and N-acetyl--d-glucosaminidase (NAG), an indicator of renal tubular cell dysfunction, as well as serum neopterin, an index of systemic immune activation, in 22 patients with cancer and seven controls. Both serum neopterin and urinary zinc were significantly elevated in cancer patients (15.8 ± 12.7 versus 7.3 ± 2.3 nmol l^–1 and 1.77 ± 0.80 versus 1.21 ± 0.41 mmol mol^–1 creatinine, P < 0 and P < 0.05, respectively), while NAG was similar in cancer patients and the controls (13.58 ± 13.80 versus 13.68 ± 12.19 kat mol^–1 creatinine). A significant correlation was observed between serum neopterin and urine zinc (rs = 0.5119, P < 0.02), serum neopterin and urine NAG (rs = 0.6761, P < 0.002), and urinary zinc and NAG (rs = 0.6348, P < 0.002). In conclusion, the present data indicate a link between urinary zinc excretion and immune activation as well as renal tubular cell dysfunction. In addition, renal tubular cell dysfunction appears to be linked to immune activation.     

Association between urinary indicators of renal dysfunction and metal concentrations in workers chronically co-exposed to cadmium,zinc and lead

The study was carried out in 31 workers co-exposed to cadmium, lead and zinc fumes and dusts in a zinc ore refinery. Urinary cadmium, lead, zinc, β₂-M levels and NAG activities were determined to evaluate the possible dose-effect relationship between these parameters. A correlation was found between urinary cadmium, lead and zinc concentrations, and urinary β₂-M levels and NAG activities of the exposed group. A statistically significant increase was also observed for urinary NAG activity in exposed workers who had urinary cadmium concentrations > 2 μg g^?1 creatinine. However, in the same exposed group, the increment of β₂-M was not statistically significant. In conclusion, the present study thus confirms the earlier observations and may suggest the notion that the urinary NAG seems to be a more sensitive indicator than urinary β₂-M level in early stages of renal injury of moderately cadmium co-exposure with lead and zinc even at urinary cadmium concentration as low as 2 μg g^?1 creatinine. When the earlier studies on the irreversibility of cadmium-induced tubular dysfunction and the present results were taken into consideration, the present health-based biological limit proposed by the WHO (5 μg g^?1 creatinine) seems to be high for the occupational exposure to cadmium.     

西格列汀对早期2型糖尿病肾病患者肾功能的影响

目的:研究西格列汀对早期2型糖尿病肾病患者肾小球、肾小管标志性蛋白/酶的影响。方法:早期2型糖尿病肾病患者72例,随机数字表分为对照组36例、治疗组36例;两组均采用糖尿病饮食管理、运动治疗,在控制血糖、血脂、血压的基础上,治疗组给予磷酸西格列汀100 mg 1粒/次,1次/天,持续服药6月。观察治疗前、后两组血肌酐(Scr)、尿素氮(BUN)、糖化血红蛋白(Hb A1c)、血脂、空腹血糖(FBG)、餐后2小时血糖(2 h PBG)、血清胱抑素-C(Cys-C)及24 h尿微量白蛋白(24 h UAE)、尿N-乙酰-β-氨基葡萄糖苷酶(NAG)、尿β2-微球蛋白(β2-MG)的变化。结果:治疗后,治疗组血脂、Hb A1c、FBG、2 h PBG较对照组明显下降,差异有显著性(P0.05)。两组患者24 h UAE、NAG、β2-MG和Cys-C较治疗前均下降,差异有显著性(P0.05);两组治疗后相比,差异具有统计学意义(P0.05)。结论:西格列汀可以有效控制早期DN患者的血糖水平,减少血清Cys-C、尿微量白蛋白水平,减轻肾小管损伤,有利于延缓DN的病程和进展。     

Low level cadmium exposure, renal and bone effects - the OSCAR study

It is well known that high cadmium exposure causes renal damage, osteoporosis and osteomalacia, whereas the dose-response relationships at low-level exposure are less well established. WHO estimated (1992) that a urinary excretion of 10 nmol/mmol creatinine would constitute a 'critical limit' below which kidney damage would not occur. Later, Belgian and Swedish studies have shown signs of cadmium induced kidney dysfunction in the general population already at urinary cadmium levels around 2-3 nmol/mmol creatinine. The Swedish OSCAR (OSteoporosis-CAdmium as a Risk factor) study comprised 1021 individuals, exposed to cadmium in the environment. Blood and urinary cadmium were used as dose estimates. Protein HC (alpha-1-microglobulin) was used as an indicator of renal tubular damage. Forearm bone mineral density (BMD) was assessed with DXA (dual energy x-ray absorptiometry) technique. The study showed that tubular proteinuria occurred at much lower levels of cadmium dose than previously known. A negative dose-effect relationship was found between cadmium dose and BMD for people at the age of 60 or older. In this age group, there was also a dose-response relationship, showing a three-fold increased risk of low BMD in the group with urinary cadmium over 3 nmol/mol creatinine, as compared to the lowest dose group. There was also evidence of an increased risk of forearm fractures with increasing cadmium levels in the population 50 years of age or older. The potential public health consequences of low level cadmium exposure should be recognized, and measures taken to reduce cadmium exposure to an absolute minimum.     

Evidence of Uncoupling between Renal Dysfunction and Injury in Cardiorenal Syndrome: Insights from the BIONICS Study

Objective

The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF).

Methods

In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF.

Results

26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF.

Conclusions

In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153).     

Kidney dysfunction and cadmium exposure--factors influencing dose-response relationships

Our early toxicological studies showed that metallothionein (MT) is a protein that carries cadmium (Cd) to the kidney, explaining why Cd exposures during long time periods may give rise to kidney dysfunction. This dysfunction is usually considered to be the critical effect, i.e. the adverse effect that occurs at the lowest exposure level. MT also provides intracellular protection against cadmium toxicity. In studies of population groups in cadmium contaminated areas in China, we investigated factors that affected the relationship between internal dose of Cd, as indicated by blood Cd (BCd) or urinary Cd (UCd), and the prevalence of kidney dysfunction. We found dose-response relationships between UCd and the prevalence of increased levels of biomarkers of renal tubular dysfunction (urinary beta-2-microglobulin, B2M, or N-acetyl-beta-d-glucosaminidase - NAG) or urinary albumin (UAlb), a biomarker of glomerular kidney dysfunction. Two years after Cd intake from contaminated rice was diminished, renal tubular dysfunction appeared unchanged or aggravated among those with higher UCd; Another 8 years later, i.e. 10 years after Cd intake was decreased, the prevalence of renal tubular dysfunction was still increased but UAlb had returned to normal. Factors that influenced the dose-response relationships were: (1) time after maximum exposure. (2) Concomitant exposure to other nephrotoxic agents such as inorganic arsenic. (3) Cd induced metallothionein mRNA levels in peripheral blood lymphocytes, used as a biomarker of the ability of each person, to synthesize MT. (4) The occurrence of increased levels in blood plasma of autoantibodies against MT. The two last points further support a role in humans of MT as a protective protein against tissue damage from cadmium and gives support to previous ideas developed partly in experimental systems.     

Urinary zinc excretion and zinc status of patients with Β-thalassemia major

In this study, zinc status and urinary zinc excretion with and without desferrioxamine (DFO) infusion and the relationship between urinary zinc excretion and renal tubular dysfunction in thalassemia major (TM) patients were investigated. Forty TM patients were given four DFO infusions on alternate days over a 1-wk period prior to the transfusion. On each day that DFO was given, a 24-h urine collection initiated. DFO was omitted for 1-wk before the following transfusion and during the period four 24-h urine collections were performed. Twenty healthy children provided 24-h urine collection as controls. Blood samples were taken on each of two consecutive transfusion days of the patients and from the controls. Urinary zinc excretion was measured and plasma and red blood cell (RBC) zinc analysis were performed by inductively coupled plasma-atomic emission spectrophotometry. UrinaryN-acetyl-Β-D-glucosaminidase (NAG) activity and creatinine were determined in morning urine specimens. The mean plasma zinc concentration was significantly lower in the patients not given DFO compared to the values of the patients given DFO and the control group. The mean RBC zinc concentration (Μmol/g Hb) in the patients (with and without DFO) and the control group were similar. Urinary zinc excretion was significantly higher in the patients receiving DFO compared to the control group, whereas urinary zinc excretion in the patients not given DFO was not different from the controls. Urinary NAG indices (U/g Cr) were significantly higher in the patients compared to controls. Urinary zinc excretion was correlated with the urinary NAG indices.     

Beta 2-microglobulinaemia: a sensitive index of diminishing renal function in diabetics.

A sensitive single measure of diminishing renal function is of importance in attempts to modify the progression of diabetic nephropathy. In 12 insulin-dependent diabetics with proteinuria plasma concentrations of beta 2-microglobulin were found to correlate more closely than plasma creatinine concentrations or creatinine clearance with glomerular function as measured by clearance of 52Cr-EDTA. The plasma beta 2-microglobulin concentration was raised in all patients with diminished glomerular filtration rate (below 80 ml/min/1.73 m2). By contrast, in two of these patients plasma creatinine concentration was normal. Plasma beta 2-microglobulin concentrations were stable throughout the day and not affected by food intake, unlike plasma creatinine concentrations, which rose in the afternoon and evening and after a meat meal. Plasma beta 2-microglobulin concentrations were the same in venous and capillary blood, the capillary blood being readily self-collected. Concentrations of beta 2-microglobulin were stable for up to 24 hours when whole blood was stored at 4 degrees C; adding aprotinin inhibited loss of beta 2-microglobulin for up to seven days. The results of this study suggest, therefore, that measuring beta 2-microglobulin concentrations is a simple and accurate method of detecting minor degrees of renal impairment and monitoring the effects of treatment.     

The postoperative stress response and its reflection in cytokine network and leptin plasma levels

The objective of the present report was to clarify the postoperative stress response of some inflammatory markers, namely of proinflammatory cytokines and leptin levels during uncomplicated postoperative periods. The results were compared with the dynamics of these parameters during intraabdominal sepsis. We followed 20 patients after a planned resection of colorectal cancer in stage Ib-IV with uncomplicated healing and 13 obese men after laparoscopic non-adjustable gastric banding. These were compared to 12 patients with proven postoperative sepsis. The control group consisted of 18 healthy men. The observed parameters included serum levels of cytokines, tumor necrosis factor-alpha (TNFalpha), interleukin-1 beta (IL-1 beta), interleukin-1 receptor antagonist (IL-1 ra), IL-6, IL-8, soluble receptor of interleukin-2 (sIL-2R) and leptin. It was found that during the first 24 h after resection there was a significant increase in the serum concentration of IL-6 up to 1125+/-240 ng/l, which declined within the next 48-72 h. Serum concentration of TNFalpha was highest 18-24 h after resection (205+/-22 ng/l) and after banding (184+/-77 ng/l). IL-1 beta had a stable serum concentration without significant elevation. Serum concentration of IL-8 after resection rose to 520+/-200 ng/l after 36-48 h. Maximal cytokine levels after gastric banding were quantitatively lower (IL-6 414+/-240 ng/l, TNFalpha 184+/-77 ng/l) than after resection. We found significant elevation of plasma leptin concentration (32+/-10 ng/ml) 24 h after banding compared with preoperative values (18+/-5 ng/ml, p 0.05). Leptin levels 48 and 72 h after banding rapidly returned to the level before operation. During abdominal surgery leptin shows to be an acute phase reactant. Proinflammatory cytokines can be main regulatory factors of leptin during this period. Significant correlation between leptin and TNFalpha (similarly demonstrated by other authors in models of bacterial inflammation) indicates that TNFalpha can be the crucial regulator of leptin generation in the early postoperative period. On the basis of our results we recommend to observe IL-6 and IL-8 at 24-72 h after the surgery in patients with a high risk of early postoperative septic complications.     

Lack of reversal effect of EDTA treatment on cadmium induced renal dysfunction: a fourteen-year follow-up

The aim of this study was to evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on cadmium (Cd) induced renal dysfunction. Seventeen workers (14 males, 3 females) were diagnosed with occupational Cd poisoning in 1986. These individuals had between 7 to 39 years of Cd exposure. From 1986 to 1999, patients received periodic EDTA therapy as part of their follow-up, all at the same hospital. Levels of urinary cadmium (UCd) and urinary beta2-microglobulin (B2M) were measured before and after each annual EDTA treatment period. Renal dysfunction was defined as urinary B2M > 0.8 mg/g Cr (creatinine). In these workers, patients with UCd level higher than 10 microg/g Cr in 1986 had abnormal B2M excretions (> or = 0.8 mg/g Cr) or trended to have abnormal B2M levels during the treatment period. However, in subjects with UCd concentration lower than 10 microg/g Cr in 1986, their urinary B2M excretions either remained normal (< 0.8 mg/g Cr) or returned to normal during the treatment period. The prevalence of renal dysfunction increased during the follow up period regardless of whether UCd levels increased or not, indicating a progressive renal dysfunction despite removal from Cd exposure. Our results suggest that reversibility of renal dysfunction caused by Cd related to the level of Cd exposure at the time of removal from exposure: renal dysfunction could be reversed if initial UCd < 10 microg/g Cr, but was irreversible when UCd > 10 microg/g Cr. Repeated examinations on these 17 Cd exposed workers from 1986 to 1999 also revealed that periodic administration of EDTA had no beneficial effects on chronic Cd-induced renal dysfunction.     

Effects of age, sex and renal function on urinary insulin-like growth factor I (IGF-I) levels in adults.

Insulin-like growth factor I (IGF-I) levels in urine were measured in adults using specific RIA after extraction with acid-ammonium sulfate. Mean (+/- SD) total urine IGF-I values were 267.9 +/- 112.9 ng/day and 167.8 +/- 73.2 ng/g creatinine (Cr) in 17 normal young adults. There was a positive correlation (r = 0.785, P < 0.001) between IGF-I values in early morning urine and those of 24 h urine when they were corrected by urinary Cr. IGF-I values in early morning urine were ranged from 60 to 1,100 ng/gCr with a mean value of 309.6 ng/gCr in 178 normal adults aged 21-80 yr. There was a consistent trend towards higher urinary IGF-I values in males during aging and this trend did not reach statistical significance until the sixth and seventh decades. There was a positive correlation (r = 0.465, P < 0.005) between urinary IGF-I values and age in males but not in females. Although urinary IGF-I values were higher in females than in males of the second and third decades, no sex difference was found in older adults. Urinary IGF-I values were correlated reversely with 24 h Cr clearance (CCr) and positively with urinary beta 2-microglobulin (beta 2-MG) levels in patients with renal dysfunction. These findings indicate that urinary IGF-I levels are influenced by age, sex and renal function in adults.