Indoleamine 2,3-dioxygenase-1, a Novel Therapeutic Target for Post-Vascular Injury Thrombosis in CKD

BACKGROUND

CKD, characterized by retained uremic solutes, is a strong and independent risk factor for thrombosis after vascular procedures . Urem ic solutes such as indoxyl sulfate (IS) and kynurenine (Kyn) mediate prothrombotic effect through tissue factor (TF). IS and Kyn biogenesis depends on multiple enzymes, with therapeutic implications unexplored. We examined the role of indoleamine 2,3-dioxygenase-1 (IDO-1), a rate-limiting enzyme of kynurenine biogenesis, in CKD-associated thrombosis after vascular injury.

METHODS

IDO-1 expression in mice and human vessels was examined. IDO-1-/- mice, IDO-1 inhibitors, an adenine-induced CKD, and carotid artery injury models were used.

RESULTS

Both global IDO-1-/- CKD mice and IDO-1 inhibitor in wild-type CKD mice showed reduced blood Kyn levels, TF expression in their arteries, and thrombogenicity compared with respective controls. Several advanced IDO-1 inhibitors downregulated TF expression in primary human aortic vascular smooth muscle cells specifically in response to uremic serum. Further mechanistic probing of arteries from an IS-specific mouse model, and CKD mice, showed upregulation of IDO-1 protein, which was due to inhibition of its polyubiquitination and degradation by IS in vascular smooth muscle cells. In two cohorts of patients with advanced CKD, blood IDO-1 activity was significantly higher in sera of study participants who subsequently developed thrombosis after endovascular interventions or vascular surgery.

CONCLUSION

Leveraging genetic and pharmacologic manipulation in experimental models and data from human studies implicate IS as an inducer of IDO-1 and a perpetuator of the thrombotic milieu and supports IDO-1 as an antithrombotic target in CKD.

Expression of xylosyltransferases I and II and their role in the pathogenesis of arthrofibrosis

BACKGROUND

Arthrofibrosis is a painful and restraining complication that occurs after about 10% of total knee arthroplasty and cruciate ligament surgery. The pathogenesis of arthrofibrosis has not yet been fully understood. Stress signals stimulate immune cells, and fibroblast differentiates into myofibroblast, which produce a large amount of collagen. Xylosyltransferases also appear to be involved in these pathways. They catalyze proteoglycan biosynthesis, which is involved in tissue remodeling and myofibroblast differentiation. The aim of this study was to investigate the relationship between the disease arthrofibrosis and the expression of the two isoforms of xylosyltransferases I and II.

METHODS

Tissue samples from 14 patients with arthrofibrosis were compared with tissue samples from seven healthy controls. The xylosyltransferases were detected by immunohistochemistry. The tissues were divided into four different areas of interest: vessels, synovialis, cell-poor and cell-rich fibrosis, or cell-poor and cell-rich areas in the control group. A quantification of the results was performed by modification of the immunoreactive score according to Remmele and Stegner.

RESULTS

Xylosyltransferase I was expressed in the various tissue types at varying rates. Xylosyltransferase I expression was considerably and significantly stronger than that of xylosyltransferase II. The following sequences of xylosyltransferase I and xylosyltransferase II expression were determined as follows: vessels >> cell-rich fibrosis > cell-poor fibrosis > synovialis. A positive correlation between the number of positive fibroblasts and the immunoreactive scoring system (IRS) was documented.

CONCLUSIONS

The significant positive correlation of xylosyltransferase -I expression with increasing number of fibroblasts demonstrates a high myofibroblast differentiation rate, which implies a gradual event as the pathogenesis of arthrofibrosis.

Cholinesterase alterations in delirium after cardiosurgery: a German monocentric prospective study

OBJECTIVES

Postoperative delirium (POD) is a common complication after elective cardiac surgery. Recent evidence indicates that a disruption in the normal activity of the cholinergic system may be associated with delirium.

DESIGN

Prospective observational study.

SETTING

Single-centre at a European academic hospital.

PRIMARY AND SECONDARY OUTCOME MEASURES

In our study the enzyme activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were determined preoperatively as well as on the first and second postoperative day. The confusion assessment method for the intensive care unit was used to screen patients for the presence of POD.

RESULTS

A total of 114 patients were included in the study. POD was associated with a decrease in BChE activity on postoperative day 1 (p=0.03). In addition, patients who developed POD, had significantly lower preoperative AChE activity than patients without POD (p<0.01). Multivariate analysis identified a preoperatively decreased AChE activity (OR 3.1; 95% CI 1.14 to 8.46), anticholinergic treatment (OR 5.09; 95% CI 1.51 to 17.23), elevated European System for Cardiac Operative Risk Evaluation (OR 3.68; 95% CI 1.04 to 12.99) and age (OR 3.02; 95% CI 1.06 to 8.62) to be independently associated with the development of POD.

CONCLUSIONS

We conclude that a reduction in the acetylcholine hydrolysing enzyme activity in patients undergoing cardiac surgery may correlate with the development of POD.

Surgeon volume and hospital volume in endocrine neck surgery: how many procedures are needed for reaching a safety level and acceptable costs? A systematic narrative review

The relationship between quality of care and provider's experience is well known in all fields of surgery. Even in thyroidectomies and parathyroidectomies, the emphasis on positive volume-outcome relationships is believed. It led us to an evaluation of volume activity's impact in terms of quality of care. A systematic narrative review was performed. According to the PRISMA criteria, we selected 87 paper and, after the study selection was performed, 22 studies were finally included in this review. All articles included were unanimous in attributing to activity volume of surgeons as well as centers a substantial importance. Some differences in outcomes between these investigated categories have been found: best results of the high volume surgeon is evident expecially in terms of complications, on the contrary best outcomes of a high volume center are mainly economics, such as hospital stay and general costs of the procedures. A cut-off of 35-40 thyroidectomies per year for single surgeon, and 90-100 thyroidectomies for single center appears reasonable for identifying an adequate activity. Concerning parathyroidectomy, we can consider reasonable a cut off at 10-12 operations/year. More studies are needed in a European or more circumscribed perspective.

Urinary Neutrophil Gelatinase Associated Lipocalins (NGALs) predict acute kidney injury post liver transplant

BACKGROUND

Acute Kidney Injury, a common complication of liver transplant, is associated with a significant increase in the risk of morbidity, mortality and graft loss. Current diagnostic criteria leaves a delay in diagnosis allowing further potential irreversible damage. Early biomarkers of renal injury are of clinical importance and Neutrophil Gelatinase Associated Lipocalins (NGALs) and Syndecan-1 were investigated.

METHODS

AKI was defined according to the Acute Kidney Injury Network criteria. Urine and blood samples were collected pre-operatively, immediately post-op and 24 h post reperfusion to allow measurement of NGAL and Syndecan-1 levels.

RESULTS

13 of 27 patients developed an AKI. Patients who developed AKI had significantly higher peak transaminases. Urinary NGAL, plasma NGAL and Syndecan-1 levels were significantly elevated in all patients post reperfusion. Urinary NGAL levels immediately post-op were significantly higher in patients who developed an AKI than those that didn't [1319 ng/ml vs 46.56 ng/ml, p ≤ 0.001]. ROC curves were performed and urinary NGAL levels immediately post-op were an excellent biomarker for AKI with an area under the curve of 0.948 (0.847-1.00).

CONCLUSIONS

Urinary NGAL levels measured immediately post-op accurately predict the development of AKI and their incorporation into clinical practise could allow early protocols to be developed to treat post transplant AKI.

Predictive value of drain pancreatic amylase concentration for postoperative pancreatic fistula on postoperative day 1 after pancreatic resection: An updated meta-analysis

BACKGROUND

Postoperative pancreatic fistula (POPF) is a potentially fatal complication following pancreaticoduodenectomy. Early prediction and exclusion of POPF may be highly advantageous to enhance patient outcomes, and accelerate recovery. In this meta-analysis, we sought to assess the prediction of drain pancreatic amylase concentration on postoperative day 1 (DPA1) for POPF.

METHODS

By searching online databases up to April 2018, all researches mentioned DPA1 for detecting POPF were analyzed. STATA 12.0 was used to analyze pooled predictive parameters.

RESULTS

Seventeen studies were finally analyzed including 4676 patients in total. The pooled sensitivity and specificity of DPA1 were respectively 0.85 (95% CI: 0.71, 0.93), 0.80 (95% CI: 0.74, 0.85) to predict overall POPF, and 0.70 (95% CI: 0.53, 0.82), 0.88 (95% CI: 0.86, 0.90) to predict CR-POPF. If pretest probability was 50%, corresponding post-test (+) were respectively 81%, 86% for overall POPF and CR-POPF when DPA1 was above cutoffs, while the post-test (-) were respectively 16%, 26% when DPA1 was under cutoffs. In subgroup analysis, sensitivities of cutoff >5000 group, 1000< cutoff <5000 group, and cutoff <1000 group were respectively 0.65 (0.43-0.82), 0.82 (0.71-0.89), 0.87 (0.78-0.92); and specificities were respectively 0.88 (0.83-0.92), 0.83 (0.77-0.88), 0.71 (0.62-0.79). Positive LR was 5.5 (3.4-8.8), 4.8 (3.4-6.7), and 3.0 (2.3-4.0) respectively. Negative LR was 0.40 (0.22-0.72), 0.22 (0.13-0.37), and 0.19 (0.11-0.32) respectively.

CONCLUSION

DPA1, which has good sensitivity and specificity, is useful for predicting overall POPF and CR-POPF, according to the present studies. Meanwhile, it should be cautious to apply because there is a wide range in cutoffs between different studies.

[Analysis of the Relationship between the Change of Drain Amylase Value and Postoperative Pancreatic Fistula after Pancreaticoduodenectomy]

To diagnose postoperative pancreatic fistula(POPF)after pancreaticoduodenectomy(PD)during early post operative days, we evaluatedwhether a change in drain amylase value(DAV), WBC value, or CRP value predicted clinically significant POPF. One hundred thirty patients underwent substomach preserving PD(SSPPD)from 2005 to 2016 in our institution andwe examinedDAV, WBC, andCRP values at POD 1, 3, and 5. Seventy-five patients(57.7%)were equivalent to ISGPF grade A at POD 3.We analyzedthese 75 cases by following 5 factors(DAV at POD 3>1,500 U/L, DAV at POD 5>1,000 U/L,WBC value at POD 5≤9,000/mL, DAV of POD 5 decreased to 1/3 from DAV of POD 3, CRP value not improved≥50%from POD 3 to 5) andwere concernedwith the crisis of the grade B/C POPF at final diagnosis after POD 5. In conclusion, DAV of POD 5 decreased to 1/3 from DAV of POD 3, andthe CRP value having not improved(≥50%from POD 3 to 5)were significant risk factors for POPF grade B andC by Cox proportional hazard models.

[Oxidative stress may cause metastatic disease in patients with colorectal cancer]

Despite surgical treatment of stage II colorectal cancer many patients will experience relapse. Inflammatory and immunologic reactions created due to the surgical stress response result in the production of reactive oxygen species. Oxidative stress in turn, may result in the stimulation of cancer cells that have not been cleared by the immune system to metastasize. In this paper we present an overview of studies where oxidative stress in relation to surgery has been linked to the development of metastatic disease.

Skeletal muscle mitochondria exhibit decreased pyruvate oxidation capacity and increased ROS emission during surgery-induced acute insulin resistance

Development of acute insulin resistance represents a negative factor after surgery, but the underlying mechanisms are not fully understood. We investigated the postoperative changes in insulin sensitivity, mitochondrial function, enzyme activities, and release of reactive oxygen species (ROS) in skeletal muscle and liver in pigs on the 2nd postoperative day after major abdominal surgery. Peripheral and hepatic insulin sensitivity were assessed by D-[6,6-²H₂]glucose infusion and hyperinsulinemic euglycemic step clamping. Surgical trauma elicited a decline in peripheral insulin sensitivity (∼34%, P<0.01), whereas hepatic insulin sensitivity remained unchanged. Intramyofibrillar (IFM) and subsarcolemma mitochondria (SSM) isolated from skeletal muscle showed a postoperative decline in ADP-stimulated respiration (V(ADP)) for pyruvate (∼61%, P<0.05, and ∼40%, P<0.001, respectively), whereas V(ADP) for glutamate and palmitoyl-L-carnitine (PC) was unchanged. Mitochondrial leak respiration with PC was increased in SSM (1.9-fold, P<0.05) and IFM (2.5-fold, P<0.05), indicating FFA-induced uncoupling. The activity of the pyruvate dehydrogenase complex (PDC) was reduced (∼32%, P<0.01) and positively correlated to the decline in peripheral insulin sensitivity (r=0.748, P<0.05). All other mitochondrial enzyme activities were unchanged. No changes in mitochondrial function in liver were observed. Mitochondrial H₂O₂ and O₂·⁻ emission was measured spectrofluorometrically, and H₂O₂ was increased in SSM, IFM, and liver mitochondria (∼2.3-, ∼2.5-, and ∼2.3-fold, respectively, all P<0.05). We conclude that an impairment in skeletal muscle mitochondrial PDC activity and pyruvate oxidation capacity arises in the postoperative phase along with increased ROS emission, suggesting a link between mitochondrial function and development of acute postoperative insulin resistance.

Gamma-glutamyl transpeptidase as the marker of kidney graft function

BACKGROUND

Gamma-glutamyl transpeptidase (GGT) is a glycoprotein of the external surface of various cell types. The activity of GGT has been observed in cells and tissues with secretory activity, such as the proximal tubular cells in kidneys. GGT also plays an important pro-oxidant role, stimulating the generation of hydroxyl radicals, and increases membrane lipid peroxidation.

OBJECTIVES

In this study we examined whether the monitoring of GGT activity in urine may be a prognostic factor of kidney allograft function. The study enrolled 107 Caucasian renal transplant recipients.

MATERIAL AND METHODS

Urine samples were collected for GGT and creatinine analysis on the 1st day after transplantation, and then in the 3rd and 12th month.

RESULTS

Higher urine GGT activity in the 3rd month after transplantation was associated with significantly higher risk of graft failure (HR=1.063 per each U/g creatinine; 95%Cl:1.004-1.127; p=0.037) in the Cox proportional hazards model. Moreover, there were positive correlations between urine GGT and the grade of interstitial fibrosis (Rs=0.64, p=0.01) and tubular atrophy (Rs=0.54, p=0.056) in specimens collected in the 3rd month after transplantation.

CONCLUSIONS

Our results suggest that higher urine GGT activity in the 3rd month after transplantation may be a prognostic factor of graft failure.

[Oxidative stress may cause metastatic disease in patients with colorectal cancer]

Despite surgical treatment of stage II colorectal cancer many patients will experience relapse. Inflammatory and immunologic reactions created due to the surgical stress response result in the production of reactive oxygen species. Oxidative stress in turn, may result in the stimulation of cancer cells that have not been cleared by the immune system to metastasize. In this paper we present an overview of studies where oxidative stress in relation to surgery has been linked to the development of metastatic disease.

Cytochrome P450 polymorphism and postoperative cognitive dysfunction

BACKGROUND

The etiology of postoperative cognitive dysfunction (POCD) remains unclear but toxicity of anesthetic drugs and their metabolites could be important. We aimed to assess the possible association between POCD after propofol anesthesia and various phenotypes owing to polymorphisms in cytochrome P450 encoding genes.

METHODS

We included patients who underwent non-cardiac surgery under total intravenous anesthesia with propofol. POCD was identified using a neuropsychological test-battery administered preoperatively, one week, and three months after surgery. Genotyping of CYP2C19*2, *3, CYP2D6*3, *4, *5 and *6 was performed using pyrosequencing, and patients were characterized according to their phenotype as ultra, extensive, intermediate, or poor metabolizers.

RESULTS

In total, 337 patients with a median age of 67 years were included. 30 (9.4%) out of the 319 patients who underwent neuropsychological testing at one week had POCD, and 24 out of 307 (7.8%) had POCD at three months. None of the examined CYP2C19, 2D6 alleles, or various phenotypes were significantly associated with POCD.

CONCLUSION

Polymorphisms in CYP2C19, or 2D6 genes do not seem to be related to the occurrence of cognitive dysfunction after non-cardiac surgery in patients anesthetised with propofol.

[Lipid peroxidation and cytochrome P-450-dependent metabolism of xenobiotics in patients with coronary heart disease and multiple organ failure]

The aim of the investigation was to study oxidative stress and hepatic monooxygenase function (HMF) in coronary heart disease (CHD) patients with multiple organ dysfunction (MOD) after myocardial revascularization. Twenty-seven CHD patients with signs of MOD and 38 patients with an uncomplicated postoperative period were examined. The intensity of MOD was rated by the SOFA scale; oxidative stress was estimated from the values of malondialdehyde, conjugate trienes, ceruplasmin, and catalase, and HMF was evaluated from antipyrine pharmacokinetic data. On postoperative day 1, the study group showed significant signs of MOD, as well as activated lipid peroxidation (LPO) and a 1.5-fold reduction in HMF. The control group displayed an insignificant HMF suppression under less marked oxidative stress. On days 3-4 after surgery, the total MOD index was noticeably lowered. Both groups exhibited a high LPO rate and enhanced HMF. On days 10-12 postoperatively, the severity of MOD corresponded to the previous period. There was a decrease in LPO activity in both groups. HMF was found to substantially reduce in the study group and to be in line with the baseline values in the control one. Correlation analysis revealed direct and inverse relationships of the indices of MOD with LPO rates and HMF. Therefore, MOD in patients with CHD is attended by increased oxidative stress and leads to a more significant HMF reduction as compared with those with an uncomplicated postoperative period. At the same time, LPO activation is one of the cardinal causes of HMF suppression. Reduced HMF may enhance the sensitivity of CHD patients to drug therapy.

Thiopurine-methyltransferase and inosine triphosphate pyrophosphatase polymorphism in a liver transplant recipient developing nodular regenerative hyperplasia on low-dose azathioprine

The enzymes thiopurine-methyltransferase (TPMT) and inosine triphosphate pyrophosphatase (ITPA) are involved in thiopurine metabolism. We describe a liver transplant recipient who presented with liver enzyme abnormalities after 78 months of low-dose azathioprine (AZA) therapy (less than 1 mg/kg). No underlying etiology of these abnormalities was identified after extensive analysis including repeated liver biopsy. Fifteen years after transplantation, the patient presented with variceal bleeding, liver biopsy showed nodular regenerative hyperplasia (NRH). TPMT*3C genotype was found in the patient's lymphocytes and heterozygous ITPA (94C>A) genotype was found in both patient and donor liver. These findings further emphasize the importance of pharmacogenetics in predicting NRH and other adverse events during AZA therapy. Furthermore, a high index of suspicion with early detection of NRH is crucial, as improvement seems only to occur in patients with compensated liver disease. Liver biopsy and discontinuation of AZA are recommended in case of liver enzyme abnormalities or signs of portal hypertension.

Incidence of Increased Creatine Kinase and its Effect on Kidney Function in Hand Assisted Laparoscopic Kidney Donors and Their Recipients

PURPOSE

Rhabdomyolysis is a rare cause of acute renal failure following laparoscopic donor nephrectomy. The incidence of rhabdomyolysis is not well known and to our knowledge the amount of creatine kinase elevation resulting in renal damage is unknown. We evaluated the incidence of increased creatine kinase, risk factors for increased creatine kinase and its effect on renal function in a series of patients undergoing hand assisted laparoscopic donor nephrectomy.

MATERIALS AND METHODS

Serum creatine kinase was prospectively measured in 74 consecutive patients who underwent hand assisted laparoscopic donor nephrectomy. These values were measured daily beginning in the recovery room. Demographic and laboratory data, and surgical parameters were analyzed to determine predictors of increased creatine kinase.

RESULTS

Eight of 74 patients (10.8%) had a creatine kinase of 2,500 IU/l or greater and 17 (23%) had a creatine kinase of 1,000 IU/l or greater. Factors associated with a creatine kinase of 2,500 IU/l or greater were operative time (320 vs 275 minutes, p = 0.01) and warm ischemia time (192 vs 138 seconds, p <0.01). Operative time remained an independent risk factor on multivariate analysis (p <0.05). There was no difference in preoperative or postoperative donor creatinine between patients with or without increased creatine kinase, although there was an increased percent change in creatinine in the increased creatine kinase group (80% vs 59%, p = 0.04).

CONCLUSIONS

Creatine kinase elevation occurs in a small but significant number of patients. Operative time was an independent risk factor for increased creatine kinase. Although creatine kinase had no significant effect on short-term creatinine, there was an increase in the percent change in donor creatinine. Finally, the long-term significance of increased creatine kinase without clinical symptoms is unknown.

Effect of renin-angiotensin aldosteron system blockers on postoperative atrial fibrillation

BACKGROUND

No randomized studies have been conducted to evaluate the effects of renin-angiotensin aldosteron system blockers on postoperative atrial fibrillation (AF). The aim of this study was to evaluate the effect of angiotensin converting-enzyme inhibitors (ACEIs) and ACEI plus candesartan, an angiotensin receptor blocker on postoperative AF.

METHODS

A group of consecutive patients undergoing coronary artery bypass and/or valve surgery was studied (n=128). The patients were randomized to ACEI group (n=49) and ACEI plus candesartan group (n=49). Thirty patients not on ACEI or angiotensin receptor blocker constituted the control group.

RESULTS

The rate of postoperative AF was higher in the control group (33.3%) compared to the ACEI group (12.2%, p=0.02) or ACEI plus candesartan group (10.2%, p=0.01). With the Cox proportional model, univariable negative predictors of postoperative AF, were the use of ACEI (RR 0.34, 95% CI 0.12 to 0.93, p=0.03) and the use of ACEI plus candesartan (RR 0.28, 95% CI 0.09 to 0.83, p=0.02); the positive predictor of postoperative AF was age>or=65 (RR 3.10, 95% CI 1.30 to 7.37, p=0.01). With the multivariable Cox proportional model, the only predictor of postoperative AF was age>or=65 (RR 9.70, 95% CI 2.04 to 46.1, p=0.004).

CONCLUSION

ACEI alone and ACEI plus candesartan decrease the incidence of postoperative AF compared to the control group. Candesartan has no additional effect on the rates of postoperative AF when added to ACEI.

Lung transplant metalloproteinase levels are elevated prior to bronchiolitis obliterans syndrome

Parenchymal disease in the allograft lung is associated with interstitial remodeling believed to be mediated by matrix metalloproteinases (MMPs). Recent studies suggest high levels of MMP-9 are associated with bronchiolitis obliterans syndrome (BOS) in lung transplant recipients. Since BOS occurs late in the posttransplant period and may be preceded by episodes of acute rejection or infection, which are associated with interstitial remodeling, we examined MMP profiles in allograft bronchoalveolar lavage (BAL) fluid in the early posttransplant period (preceding BOS). Gelatin zymography, protein array analysis and specific ELISA on BAL fluids from transplanted lungs indicated that MMP-8, MMP-9 and TIMP-1 were strongly expressed in allograft BAL fluid from stable patients, or those with infection or rejection compared to BAL fluid from normal volunteers. Elevated expression of MMP-8, MMP-9 and TIMP-1 occurred early, and was sustained for the 3.2 years covered in this study. Elevations of MMP-8, MMP-9 and TIMP-1 in the first 2 years posttransplant appear to be associated with lung transplantation itself, and not infection or rejection. These data suggest that ongoing and clinically silent MMP activity could perpetuate progressive disease in the allograft lung.

An endoscopic sphincterotomy of the minor papilla in the management of symptomatic pancreas divisum

BACKGROUND/AIMS

The efficacy of endoscopic treatment in pancreas divisum remains controversial. This study evaluated the results of an endoscopic sphincterotomy of the minor papilla and temporary transpapillary pancreatic stenting in patients with pancreas divisum.

METHODOLOGY

Pancreas divisum was diagnosed in four patients between 1994 and 2004. All patients demonstrated episodes of recurrent upper abdominal and back pain were with a median follow-up period of 14.5 months. One patient was treated by a sphincterotomy of the minor papilla alone, while three others also underwent transpapillary pancreatic stent insertion for seven days.

RESULTS

A Sphincterotomy of the minor papilla could be successfully achieved in all patients. There was no instance of bleeding, perforation or sepsis after the procedure. The postoperative serum amylase level in the patients without stent insertion (1352 IU/L) was higher than that the patients with stents (mean level 515 IU/L, range 358 to 680). The dilatated dorsal pancreatic ducts were found to improve after a sphincterotomy in all patients. None of the patients had any further episodes of pancreatitis. In addition, all patients demonstrated a considerable improvement in their upper abdominal or back pain symptoms, which did not require either analgesic medication or hospitalization.

CONCLUSIONS

An endoscopic sphincterotomy and temporary transpapillary pancreatic stenting were therefore suggested to be a beneficial treatment modality for patients with pancreas divisum.

Effects of cholecystectomy (laparoscopic versus open) on PMN-elastase

BACKGROUND/AIMS

Polymorphonuclear leukocytes (PMN) are well recognized as being the principal cells in inflammatory response reaction. During the surgical procedures there is a massive release of elastase (PMN-elastase) from the neutrophils, along with other proteinases. Therefore the measurement of the PMN-elastase might be a useful indicator of the degree of surgical trauma. Laparoscopic cholecystectomy (LC) is a so-called "mini-invasive" surgical procedure and on the basis of this consideration the aim of the present prospective, non-randomized study, is to examine (a) whether the serum levels of PMN-elastase concentration are modified and how, in patients undergoing LC compared to patients undergoing open cholecystectomy (OC), (b) whether these findings are indicative of an increased risk to develop infectious complications and therefore whether they are clinically significant.

METHODOLOGY

Plasma granulocyte elastase was determined photometrically, using an immune-activation immunoassay, in 86 patients (42 patients underwent OC and 44 LC). The levels of C reactive protein (CRP), an acute phase protein, were measured using a competitive CRP ELISA kit. Blood samples were collected from all patients a day before operation and at days 1, 3, 6 and 12 after operation. We established a reference range for elastase by measuring the serum elastase concentration in 68 normal control patients without gallbladder cholelithiasis or other diseases.

RESULTS

On day, 1, 3 and 6 after surgery, patients that underwent OC showed a significant increase (p < 0.05) in plasma elastase concentration, while it was almost unchanged in LC patients. The mean values of the serum CRP on p.o. days 1, 3 and 6 were also significantly lower in the LC group than those in OC group (p < 0.05). We recorded three cases (7.1%) of postoperative infections in the "open" group. The CRP concentration remained high for 1, 3 and 6 days and normalized 10-12 days after surgery while the PMN-elastase normalized after 13, 14 and 16 days.

CONCLUSIONS

The peripheral leukocyte function may be better preserved after LC in comparison to OC. Laparoscopic surgery, associated with a small skin incision and the avoidance of open laparotomy, can thus minimize surgical stress, and provide more favorable postoperative conditions for patients. Indeed excessive and prolonged post-injury elevations of PMN-elastase and CRP are associated with increased morbidity. Moreover, the PMN-elastase is a more sensible marker of inflammation in comparison to the CRP.

NADPH oxidase inhibition improves neurological outcomes in surgically-induced brain injury

Neurosurgical procedures can result in brain injury by various means including direct trauma, hemorrhage, retractor stretch, and electrocautery. This surgically-induced brain injury (SBI) can cause post-operative complications such as brain edema. By creating a mouse model of SBI, we tested whether NADPH oxidase, an important reactive oxygen species producing enzyme, is involved in SBI using transgenic mice lacking gp91phox subunit of NADPH oxidase (gp91phox KO) and apocynin, a specific inhibitor of NADPH oxidase. Neurological function and brain edema were evaluated at 24 h post-SBI in gp91phox KO and wild-type littermates grouped into SBI and sham-surgery groups. Alternatively, mice were grouped into vehicle- and apocynin-treated (5 mg/kg, i.p. 30 min before SBI) groups. Oxidative stress indicated by lipid peroxidation (LPO) was measured at 3 and 24 h post-SBI. The gp91phox KO mice, but not the apocynin-treated mice showed significantly improved neurological scores. Brain edema was observed in both gp91phox KO and wild-type groups after SBI; however, there was no significant difference between these two groups. Brain edema was also not affected by apocynin-pretreatment. LPO levels were significantly higher in SBI group in both gp91phox KO and wild-type groups as compared to sham group. A trend, although without statistical significance, was noted towards attenuation of LPO in the gp91phox KO animals as compared to wild-type group. LPO levels were significantly attenuated at 3 h post-SBI by apocynin-pretreatment but not at 24 h post-SBI. These results suggest that chronic and acute inhibition of NADPH oxidase activity does not reduce brain edema after SBI. Long-term inhibition of NADPH oxidase, however improves neurological functions after SBI.

Leukocyte-derived inducible nitric oxide synthase mediates murine postoperative ileus

OBJECTIVE

To provide evidence that iNOS expression solely in leukocytes plays a role in postoperative ileus.

SUMMARY BACKGROUND DATA

Intestinal handling initiates a molecular and cellular muscularis inflammation that has been associated with iNOS expression and ileus. The specific cellular source of iNOS is a matter of speculation.

METHODS

Chimeric mice were constructed that selectively express the iNOS gene only in their leukocytes or only in their parenchymal cells by lethal radiation and reconstitution with reciprocal bone marrow. Mild intestinal manipulation was used to induce postoperative ileus.

RESULTS

Intestinal manipulation caused a significant leukocyte extravasation into the muscularis of all groups. Postoperative iNOS mRNA expression was evident in iNOS and transplanted iNOS mice with iNOS bone marrow but not in iNOS animals. The loss of the iNOS gene in leukocytes of iNOS mice reduced iNOS mRNA expression by 59%. iNOS-deficient mice and iNOS animals with iNOS leukocytes presented with a significant improvement in postoperative intestinal transit and in vitro smooth muscle contractility, whereas the replacement with iNOS bone marrow in iNOS mice completely reversed this improvement.

CONCLUSION

These results clearly show that iNOS expressed in leukocytes within the intestinal muscularis plays a major role in mediating smooth muscle dysfunction and subsequently postoperative ileus.

Matrix metalloproteinase gelatinase B (MMP-9) is associated with leaking glaucoma filtering blebs

The goal of glaucoma filtering surgery is to create a low resistance pathway for aqueous outflow. The result is a blister or 'bleb' on the conjunctiva, from which fluid drains into the vasculature. Filtering surgery results may be compromised if blebs develop leaks, a problem that surfaces more frequently when antimetabolites are used to control the wound healing response. We investigated the role of tissue remodelling enzymes of the Matrix metalloproteinase (MMP) family in the development of bleb leaks. Our design was a case series. We enrolled glaucoma patients with leaking blebs, glaucoma patients with overhanging blebs and normal eyes. Leaking bleb tissues (n=11) and bleb leak fluid were collected from patients undergoing bleb revision surgery. Overhanging bleb tissues (from non-leaking blebs, n=3), normal conjunctiva (n=8), and aqueous humour (n=4) were collected for comparison. Samples were analysed for MMP content and proteinase activity by the methods of zymography, western blotting, immunohistochemistry, and in situ zymography. Our main outcome measures were presence and activity of MMP in sample. Zymography revealed the presence of a high molecular weight caseinase and a 92-kDa gelatinase of a size appropriate for the proenzyme form of gelatinase B (gelB; MMP-9), in extracts from leaking bleb tissue, but not in bleb leak fluid or aqueous humour samples. In contrast, a 65-kDa gelatinase of a size appropriate for gelatinase A (MMP-2) proenzyme was observed in all samples. All proteinases disappeared when 10mm EDTA was added to the development buffer, consistent with their identity as MMPs. Western blotting and immunohistochemical analyses confirmed the identity of the 92kDa proteinase as gelB, and further revealed its absence from extracts of overhanging bleb tissue and normal conjunctiva. In situ zymography demonstrated strong gelatinolytic activity in leaking bleb tissue, but not overhanging bleb tissue or normal conjunctiva. MMP-g may be involved in the mechanism of formation of bleb leaks. Precise description of the cascade of events leading to bleb leakage may allow the design of therapeutic interventions to prevent, stabilize or reverse bleb leakage.

Ectonucleotidases of CD39 family modulate vascular inflammation and thrombosis in transplantation

Transplantation results in exposure of the graft vasculature to warm and cold ischemia, followed by perfusion by circulating blood constituents and obligatory oxidant stress. Further graft injury occurs as consequences of acute humoral cellular rejection or chronic transplant vasculopathy, or both. Extracellular nucleotide stimulation of purinergic type 2 (P2) receptors are key components of platelet, endothelial cell (EC), and leukocyte activation resulting in vascular thrombosis and inflammation in vivo. CD39, the prototype nucleoside triphosphate diphosphohydrolase (NTPDase-1) is highly expressed on endothelium; in contrast, CD39L1/NTPDase-2 (a preferential adenosine triphosphatase [ATPase]) is found on vascular adventitial cells. Both ectoenzymes influence thrombogenesis by the regulated hydrolysis of extracellular nucleotides that differentially regulate P2-receptor activity and function in platelets and vascular cells. The intracytoplasmic domains of NTPDase-1 may also independently influence cellular activation and proliferation. NTPDase activity is substantively lost in the vasculature of injured or rejected grafts. A role for NTPDase-1 in thromboregulation has been validated by generation of mutant mice either null for cd39 or overexpressing human CD39. Administration of soluble NTPDase or induction of CD39 by adenoviral vectors, or both, are also of benefit in several models of transplantation. Administration of soluble CD39 or targeted expression may have future therapeutic application in transplantation-associated and other vascular diseases.

Transaminitis after pancreatic islet transplantation

BACKGROUND

An asymptomatic, self-limited transaminitis uniformly follows pancreatic islet transplantation (PIT) performed through portal vein (PV) infusion. The underlying cause and significance of this transaminitis is unclear.

STUDY DESIGN

Records of all patients with insulin-dependent diabetes mellitus who had undergone PIT at our institution were reviewed. All PITs were performed in conjunction with a remote pancreatic islet isolation center and done through percutaneous transhepatic PV infusion. Alanine aminotransferase (ALT) levels, serum glucose concentrations, insulin requirements, and color-flow Doppler ultrasonography examinations of the right upper quadrant were assessed before and after PIT.

RESULTS

Eleven patients have undergone a total of 26 PITs. An elevated ALT level occurred in all 11 patients (100%) after the first PIT, with the median post-PIT peak ALT level reaching 187 IU/L. Transaminitis was less frequent and less marked after the second PIT. A negative correlation between viability of the pancreatic islets transplanted (r = -0.44, p = 0.03) and a positive correlation between the ratio of maximum to initial PV pressure (r = 0.41, p = 0.04) were seen with the subsequent ALT peak. Color-flow Doppler ultrasonography examinations showed no occurrences of PV thrombosis or intrahepatic hematoma. Finally, the degree of transaminitis did not correlate with post-PIT insulin requirements, indicating that post-PIT transaminitis cannot be used to measure allograft rejection or function.

CONCLUSIONS

Transaminitis after PIT is common and self-limited. Post-PIT transaminitis does not signal acute rejection or serious procedure-related complications such as PV thrombosis or intrahepatic hematoma.

The effect of inducible nitric oxide synthase on postoperative adhesion formation in rats

OBJECTIVE

To evaluate the effect of iNOS on adhesion formation and to assess whether inhibition of iNOS expression affected adhesion formation according to adhesion maturation days.

STUDY DESIGN

Forty Wistar Albino rats were subjected to standardized lesion by cecal abrasion and parietal peritoneal defect and were randomly divided into four groups. Group I (control) received no treatment; groups II-IV received N-acetyl-cystein (NAC) 15 mg/100 g per day intramuscularly on days 4-14, 0-14 and 0-3, respectively, after surgery. On the postoperative 14th day adhesion score, tissue iNOS expression, inflammatory cell reaction (ICR) and tissue fibrosis score were determined.

RESULTS

Inflammation score of groups I and II was lower than that of groups III and IV (P < 0.05). Adhesion scores and tissue fibrosis of group II were significantly lower than that of the other groups (P < 0.001).

CONCLUSION

iNOS inhibition during the first 3 days postoperatively caused a delay in the resolution of inflammatory cell reaction. On the other hand, when inhibited after the first 3 days, adhesion formation and fibrosis were reduced both clinically and histopathologically.

The clinical significance of monitoring alkaline phosphatase level to estimate postoperative liver failure after hepatectomy

BACKGROUND/AIMS

To predict the occurrence of postoperative liver failure after hepatectomy, the clinical significance of monitoring alkaline phosphatase (ALP) has been studied, and the relationship between the change of total bilirubin and the level of ALP or gamma-glutamyl transpeptidase (gamma-GTP) after hepatectomy was evaluated.

METHODOLOGY

The 163 patients, who underwent hepatectomy at our institute for the past 12 years, were divided into three groups according to the postoperative events. HF consisted of 5 patients with liver failure, HB showed the postoperative high bilirubinemia (over 5mg/dL) in 13 cases and GP were 145 cases without any postoperative problems.

RESULTS

1. The postoperative highest level of total bilirubin (T-Bil) correlated with the decreasing rate of ALP, prothrombin time (PT), total cholesterol (T-CHO) or gamma-GTP and total blood loss (p<0.01). 2. The level of ALP decreased after hepatectomy significantly and the decreasing rate was serious in HB and HF (p<0.05). 3. The recovering time to preoperative level of ALP was clearly shorter in GP than in HB and HF. 4. The level of ALP and gamma-GTP at the point where the level of T-Bil increased over 5mg/dL, was useful to distinguish between HF and HB. 5. The good correlation between postoperative level of ALP and gamma-GTP was noted. The decreasing levels of ALP and gamma-GTP were found to be critical below 80% and 55% after bisegmentectomy. Furthermore, the recovered levels of ALP and gamma-GTP were important to distinguish between HF and HB.

CONCLUSIONS

Monitoring the ALP level was indicated to be useful to estimate the postoperative course of bilirubin.

Clinical relevance of angiotensin-converting enzyme gene polymorphisms to predict risk of mechanical ventilation after coronary artery bypass graft surgery

OBJECTIVE

Prolonged mechanical ventilation is a significant complication after coronary artery bypass graft surgery. Angiotensin-converting enzyme mediates ischemia-reperfusion injury, which is an important mechanism of postcoronary artery bypass graft complications. An insertion/deletion polymorphism within the angiotensin-converting enzyme gene is associated with variable concentrations of angiotensin-converting enzyme. Whether this polymorphism is associated with prolonged mechanical ventilation is not known. The primary objective was to determine whether the insertion/deletion angiotensin-converting enzyme gene polymorphism is associated with prolonged mechanical ventilation. The release of inflammatory mediators and risk of prolonged mechanical ventilation are higher after conventional coronary artery bypass graft compared with off-pump coronary artery bypass graft. Therefore, we examined the risk of prolonged mechanical ventilation for angiotensin-converting enzyme genotypes in patients undergoing conventional coronary artery bypass graft and off-pump coronary artery bypass graft separately. Tumor necrosis factor down-regulates angiotensin-converting enzyme concentrations, and functional polymorphisms within the tumor necrosis factor gene have been associated previously with prolonged mechanical ventilation. Therefore, we examined interactions between these polymorphisms.

DESIGN

Prospective observational cohort study.

SETTING

Tertiary care center.

SUBJECTS

Patients who underwent coronary artery bypass graft (with or without valve replacement surgery).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured angiotensin-converting enzyme genotype and time to extubate. Patients with the DD and DI genotypes were at higher risk of prolonged mechanical ventilation compared with those with the II genotypes (hazard ratio = 2.2 and 1.6, respectively, p =.0005). Interactions were seen between the angiotensin-converting enzyme genotypes with surgical technique and with tumor necrosis factor-308/lymphotoxin + 250 GG haplotype for prolonged mechanical ventilation (p =.078 and.0003, respectively). The association was stronger for those undergoing conventional coronary artery bypass graft, whereas neither angiotensin-converting enzyme genotype conferred higher risk to those undergoing off-pump coronary artery bypass graft.

CONCLUSIONS

Angiotensin-converting enzyme gene polymorphisms are associated with respiratory complications postcardiopulmonary bypass. The increased risk associated with genotype may be amenable to alternative surgical technique or pharmacologic manipulation.

Blockade of the extracellular signal-regulated kinase pathway by U0126 attenuates neuronal damage following circulatory arrest

OBJECTIVES

The extracellular signal-regulated kinase pathway of the mitogen-activated protein kinase signal transduction cascade has been implicated in the neuronal and endothelial dysfunction witnessed following cerebral ischemia-reperfusion injury. Extracellular signal-regulated kinase is activated by mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2. We evaluated the ability of a mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2-specific inhibitor (U0126) to block extracellular signal-regulated kinase activation and mitigate ischemic neuronal damage in a model of deep hypothermic circulatory arrest.

METHODS

Piglets underwent normal flow cardiopulmonary bypass (control, n = 4), deep hypothermic circulatory arrest (n = 6), and deep hypothermic circulatory arrest with U0126 (n = 5) at 20 degrees C for 60 minutes. The deep hypothermic circulatory arrest with U0126 group was given 200 microg/kg of U0126 45 minutes prior to initiation of bypass followed by 100 microg/kg at reperfusion. Following 24 hours of post-cardiopulmonary bypass recovery, brains were harvested. Eleven distinct cortical regions were evaluated for neuronal damage using hematoxylin and eosin staining. A section of ischemic cortex was further evaluated by immunohistochemistry with rabbit polyclonal antibody against phosphorylated extracellular signal-regulated kinase 1/2.

RESULTS

The deep hypothermic circulatory arrest and deep hypothermic circulatory arrest with U0126 groups displayed diffuse ischemic changes. However, the deep hypothermic circulatory arrest with U0126 group possessed significantly lower neuronal damage scores in the right frontal watershed zone of cerebral cortex, basal ganglia, and thalamus (P < or =.05) and an overall trend toward neuroprotection versus the deep hypothermic circulatory arrest group. This neuroprotection was accompanied by nearly complete blockade of phosphorylated extracellular signal-regulated kinase in the cerebral vascular endothelium.

CONCLUSIONS

In this experimental model of deep hypothermic circulatory arrest, U0126 blocked extracellular signal-regulated kinase activation and provided a significant neuroprotective effect. These results support targeting of the extracellular signal-regulated kinase pathway for inhibition as a novel therapeutic approach to mitigate neuronal damage following deep hypothermic circulatory arrest.

Comparison of different cardiac markers in monitoring percutaneous coronary interventions with frequent use of stents and gpIIbIIIa-antagonists

Studies from the early 1990s found elevations of creatine kinase (CK) and its isoform CK-MB in 5-30% of patients after PCI, indicating minor myocardial damage. Less is known about the influence of modern improved PCI-techniques on the frequency of elevated cardiac markers and the correlation between different commonly used markers, especially cardiac troponins. From 1997 to 2001, 1486 patients undergoing PCI during the regular working hours were included in the prospective "Ludwigshafen Infarctlet Registry". Myocardial infarction in the past 48 hours was an exclusion criterion. Clinical and procedural data were documented. Follow-up data were obtained from discharge up to one year. PCI-related elevations of troponin T were found in 18%, of total-CK in 11%, of CK-MB in 33% and of myoglobin in 23% of cases. The correlation between the different markers was poor. Compared with troponin T, other markers showed low sensitivity (total-CK 58%, CK-MB 27%, myoglobin 22%) and, especially total-CK, low specificity. Stenting, side branch occlusion or major dissection, complex lesion morphology, gpIIbIIIa-antagonist application, proximal stenosis and unstable angina were independent predictors of an elevated troponin T in multivariate analysis. Due to this weak correlation between more specific and sensitive troponins and the other markers, troponins are preferred in monitoring after PCI. In addition to lesion characteristics, particularly stenting is associated with an increased rate of elevated troponin.

COX-2 dependent inflammation increases spinal Fos expression during rodent postoperative ileus

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) and prostaglandins (PGs) participate in the pathogenesis of inflammatory postoperative ileus. We sought to determine whether the emerging neuronal modulator COX-2 plays a significant role in primary afferent activation during postoperative ileus using spinal Fos expression as a marker.

METHODS

Rats, and COX-2(+/+) and COX-2(-/-) mice underwent simple intestinal manipulation. The effect of intestinal manipulation on Fos immunoreactivity (IR) in the L(5)-S(1) spinal cord, in situ circumference, and postoperative leucocytic infiltrate of the intestinal muscularis was measured. Postoperative PGE(2) production was measured in peritoneal lavage fluid. The dependence of these parameters on COX-2 was studied in pharmacological (DFU, Merck- Frosst, selective COX-2 inhibitor) and genetic (COX-2(-/-) mice) models.

RESULTS

Postoperative Fos IR increased 3.7-fold in rats and 2.2-fold in mice. Both muscularis leucocytic infiltrate and the circumference of the muscularis increased significantly in rats and COX-2(+/+) mice postoperatively, indicating dilating ileus. Surgical manipulation markedly increased PGE(2) levels in the peritoneal cavity. DFU pretreatment and the genetic absence of COX-2(-/-) prevented dilating ileus, and leucocytic infiltrate was diminished by 40% with DFU and by 54% in COX-2(-/-) mice. DFU reversed postsurgical intra- abdominal PGE(2) levels to normal. Fos IR after intestinal manipulation was attenuated by approximately 50% in DFU treated rats and in COX-2(-/-) mice.

CONCLUSIONS

Postoperatively, small bowel manipulation causes a significant and prolonged increase in spinal Fos expression, suggesting prolonged primary afferent activation. COX-2 plays a key role in this response. This activation of primary afferents may subsequently initiate inhibitory motor reflexes to the gut, contributing to postoperative ileus.

Cardiac allograft vasculopathy and dysregulation of the NO synthase pathway

Cardiac allograft vasculopathy is the most aggressive form of atherosclerosis in humans and is the leading cause of death after the first year of heart transplantation. Endothelial dysfunction is a major contributing factor to the acceleration of coronary vascular disease in these individuals. A reflection of this endothelial dysfunction is the severe impairment in endothelium-dependent vasodilation that occurs early after transplantation. The etiology of this allograft endothelial alteration is multifactorial and may include preexisting atherosclerosis of the graft vessels, reperfusion injury during transplantation, denervation, disruption of the lymphatic system, and acute and chronic immune injury, as well as traditional risk factors for coronary artery disease (hyperlipidemia, diabetes, hypertension, or hyperhomocysteinemia) and pathogens, such as cytomegalovirus. The alteration in endothelial function affects vasomotor tone of the coronary arteries. Evidence indicates that there may be an impairment of endothelial production and/or activity of NO. Because NO is a potent vasodilator, its deficiency would explain the abnormal vasomotor tone in these individuals. In addition, because NO inhibits key processes in vascular inflammation and atherosclerosis, its absence may contribute to the acceleration of transplant vascular disease. Recent studies from our group and others have shed light on the mechanisms of endothelial dysfunction and its importance in cardiac allograft vasculopathy. In addition, the alteration in endothelial function contributes to vascular inflammation and progression of the disease.

Matrix metalloproteinase inhibition modulates postoperative scarring after experimental glaucoma filtration surgery

PURPOSE

To determine whether postoperative application of a broad-spectrum matrix metalloproteinase (MMP) inhibitor, GM6001 (ilomastat), reduces scarring after glaucoma filtration surgery.

METHODS

In a randomized, prospective, masked-observer study, 40 New Zealand White rabbits underwent modified glaucoma filtration surgery. The animals were randomly allocated to receive postoperative subconjunctival injections of either phosphate-buffered saline (PBS) or 100 microM ilomastat for 10 days. The animals were killed on days 7, 14, 21, and 30. Clinical characteristics, which included bleb morphology and intraocular pressure, were recorded. Tissue sections were immunohistochemically stained for alpha smooth muscle actin (alphaSMA) and extracellular matrix components in the two groups.

RESULTS

Surgical outcome was significantly prolonged in the ilomastat-treated group compared with the vehicle-treated group (P < 0.001). At day 30, all the blebs had survived except two in the ilomastat-treated group, whereas no blebs survived to day 30 with vehicle treatment (n = 11). The intraocular pressure remained significantly lower throughout the course of the experiment in the ilomastat group compared with the vehicle group (P < 0.0017). Histologically, less scar tissue was observed at the sclerostomy site with inhibition of MMP, compared with vehicle treatment.

CONCLUSIONS

The data presented suggest that the healing response after surgery can be modulated by inhibiting the effects of MMPs. Inhibition of MMP significantly improved surgical outcome by reducing the amount of scar tissue produced. By targeting the actions of these proteolytic enzymes, a more controlled and physiological method of modulating scarring may be achieved.

Transient up-regulation of spinal cyclooxygenase-2 and neuronal nitric oxide synthase following surgical inflammation

BACKGROUND

Surgery induces pain and hyperalgesia postoperatively. The products of cyclooxygenases and nitric oxide synthase (NOS) have been implicated in the development of inflammatory pain and hyperalgesia experimentally, and the use of drugs clinically that modify cyclooxygenase activity has been advocated in the management of perioperative pain. However, regulation of these enzymes following surgery has not been studied.

METHODS

Adult female sheep (n = 12) undergoing a midline laparotomy for collection of ova were used in this study. Lumbar and cervical spinal cord tissue was collected from animals euthanized 1 day and 6 or 7 days after surgery and processed for cyclooxygenase (cyclooxygenase-1 and cyclooxygenase-2), neuronal NOS mRNA expression using reverse-transcription polymerase chain reaction and hybridization. Tissues were also processed for NADPH-diaphorase staining and cyclooxygenase-1 and cyclooxygenase-2 protein expression by immunohistochemistry and Western blotting.

RESULTS

No alteration in cyclooxygenase-1 or cyclooxygenase-2 mRNA or protein concentrations were detected in spinal cord by reverse-transcription polymerase chain reaction and Western blotting, respectively, at 1 day or 6 or 7 days after surgery. However, using techniques that localize mRNA and protein expression ( hybridization and immunohistochemistry, respectively), increases in cyclooxygenase-2 were identified in lamina V dorsal horn neurons in lumbar spinal cord 1 day after surgery. A significant increase in neuronal NOS mRNA was observed in lumbar spinal cord 1 day after surgery, localized to laminae I-II and lamina V neurons, which returned to baseline concentrations by 6 to 7 days. NADPH-diaphorase staining was significantly increased in laminae I-II in lumbar spinal cord 1 day after surgery but not after 6 to 7 days.

CONCLUSIONS

Spinal cyclooxygenase and neuronal NOS pathways are differentially altered following surgical inflammation. The early and transient nature of these changes suggests that these enzymes are implicated in postoperative pain and hypersensitivity.

Expression of SHP-1 phosphatase indicates post-germinal center cell derivation of B-cell posttransplant lymphoproliferative disorders

SHP-1 tyrosine phosphatase acts as a negative regulator of signaling by receptors for growth factors, cytokines, and chemokines and by receptors involved in immune response. Our recent study showed that SHP-1 is tightly regulated at various stages of B-cell differentiation and is expressed in the mantle and marginal zones, interfollicular B cells, and plasma cells, whereas it is nondetectable in germinal center cells. In this study we evaluated expression of SHP-1 in vitro and in vivo in nine cell lines representing three different types of EBV+ B-cell populations closely resembling or derived from posttransplant lymphoproliferative disorders (PTLDs). Furthermore, we examined tissue samples from 58 patients with B-cell PTLDs, both EBV+ (85% of the cases analyzed) and EBV- (15%). SHP-1 protein was strongly expressed in all cell lines and PTLD cases. In addition, the PTLD cases were essentially negative for germinal center B-cell markers: none expressed CD10 and only one expressed BCL-6. More than 40% expressed a late post-germinal B-cell marker, CD138. The universal expression of SHP-1, lack of expression of CD10 and BCL-6, and frequent expression of CD138 suggest that PTLDs are derived from post-germinal center B cells regardless of the EBV cell infection status. Based on the immunophenotype, B-cell PTLDs could be divided into two broad categories corresponding to the early (CD10-/BCL-6-/SHP-1+/CD138-) and late (CD10-/BCL-6-/SHP-1+/CD138+) post-germinal center cells. By being expressed earlier, SHP-1 is a more sensitive marker of post-germinal center B cells than CD138, which is seen on the terminally differentiated immunoblasts and plasma cells.

Impact of perioperative myocardial injury on early and long-term outcome after coronary artery bypass grafting

AIMS

To establish the influence of perioperative myocardial injury on short- and long-term survival after coronary artery bypass grafting (CABG).

METHODS AND RESULTS

The correlation of postoperative serum aspartate aminotransferase and creatine kinase MB to early cardiac-related death and to late survival was evaluated in 4911 patients who underwent CABG consecutively during a 6-year period. There were 93 early deaths (1.9%), 73 of them cardiac-related (1.5% of 4911). After a mean follow-up of 5 years, 409 additional deaths (8.5% of 4818) had occurred. Elevated enzyme levels on day 1 postoperatively highly increased the risk of early cardiac death (serum aspartate aminotransferase >or=2.35 microkat.l(-1): odds ratio 9.2; serum creatine kinase MB >or=61 microg.l(-1): odds ratio 6.0), and increased the risk of late death by approximately 50% (serum aspartate aminotransferase >or=2.35 microkat.l(-1): relative hazard 1.5; serum creatine kinase MB >or=61 microg.l(-1): relative hazard 1.4). This increased risk of death was independent of other risk factors and remained constant over time.

CONCLUSIONS

Enzyme elevation after CABG implied an increased risk of both early and late death. The long-term effect persisted many years after surgery.

Elastase release following myocardial ischemia during extracorporeal circulation (ECC) -- marker of ongoing systemic inflammation?

BACKGROUND

'Post-Perfusion Syndrome' (PPS) after cardiopulmonary bypass (CPB) is known to be evoked by inflammatory reactions. The hypothesis of a pathogenetic role for the neutrophil granulocytes in this inflammation would be strengthened if elevated concentrations of a neutrophil product such as elastase could be demonstrated, particularly in case of a PPS or a systemic inflammatory response syndrome (SIRS).

METHODS

In a randomized prospective double-blind study, 40 patients undergoing aortocoronary bypass grafting (CABG) were divided into 4 groups of 10 patients each. One group served as the control group, one received prostacyclin (PGl 2 ), the third group was substituted with high-dosed aprotinin and the last group was treated with a combination of PGl 2 and aprotinin. 6 blood samples were taken from every patient perioperatively, and plasma elastase (PE), procalcitonin (PCT), C 1 -esterase inhibitor (CEI) and parameters of coagulation and fibrinolysis were determined.

RESULTS

Levels of elastase increased significantly in all intra- and postoperative blood samples compared to the preoperative baseline values (< 30 microg/l, p < 0.05). The elastase release was even more pronounced in the control and aprotinin group (170 +/- 23 microg/l; 175 +/- 14 microg/l during ECC) compared to patients who received prostacyclin (142 = 21 microg/l, p < 0.05). Duration of myocardial ischemia could be directly correlated to elastase levels at the end of CPB. 10 of the 40 patients suffered postoperatively from a PPS or a SIRS; in these patients, elastase levels at the end of CPB were significantly higher (188 +/- 26 microg/l vs. 138 +/- 22 microg/l, p < 0.05). Immediately after the operation, these 10 patients also showed significant changes in the cascades of coagulation and fibrinolysis resulting in a hypercoagulatory state. Levels of PCT and CEI did not change significantly during and after ECC.

CONCLUSIONS

Our results indicate that CPB initiates an elastase release that can be suppressed by prostacyclin. Increased intraoperative elastase levels in patients with PPS show that elastase may be an indicator of ongoing systemic inflammation, possibly causing complications due to a hypercoagulatory state. Myocardial ischemia seems to be one reason for this elastase release. It can be speculated that early PGl2-infusion could be a therapeutic option in inflammatory diseases caused by ECC.

[Coronary revascularization: off-pump versus on-pump--a comparison of behavior of biochemical cardiac ischemia markers]

BACKGROUND

Recently, coronary artery bypass grafting (CABG) on the beating heart with avoidance of extracorporeal circulation (off-pump CABG technique) has been gaining increasing importance in modern cardiac surgery. The object of this prospective study was to compare postoperative kinetic and patterns of cardiac troponin I (cTnI), T (cTnT), and creatine kinase MB (CKMB) activities after off-pump CABG versus conventional on-pump CABG.

METHODS

We studied 106 patients who underwent first-time elective on-pump (group I, n = 69, 56 male, 13 female, mean age: 64.3 +/- 9.9 years, mean ejection fraction: 56 +/- 15%) or off-pump (group II, n = 37, 24 male, 13 female, mean age: 68.4 +/- 9.1 years, mean ejection fraction: 57 +/- 13%) CABG surgery via median sternotomy. CTn I and cTnT levels, total creatine kinase (CK) and CK-MB activities in the serum were measured before operation, up on arrival at the ICU and 6, 12, 24, 48 and 120 hours later. Serial 12-lead ECGs were recorded preoperatively and on days 1, 2 and 5.

RESULTS

Serum concentrations of cardiac troponins in all patients were preoperatively either not detectable or in the normal range and significantly increased after surgery. In group I, one patient developed a Q wave myocardial infarction, one patient a non-Q wave infarction and two patients a new left bundle branch block on the ECG. One patient of group II developed a new Q-wave myocardial infarction and another patient permanent atrial fibrillation associated with a continuous arrhythmia. All patients with a myocardial infarction in the ECG showed significant elevation of concentrations or activities of these biochemical markers. The median postoperative peak values for cTnI were measured at 24 h in both groups (2.7 micrograms/l, 95%-CI: [2.2, 3.2] in group I and 1.1 micrograms/l, 95%-CI: [0.5, 1.3] in group II). CTnT postoperatively presented an earlier median peak of 0.128 microgram/l at 12 h in group II (95%-CI: [0.041, 0.146]) than in group I at 48 h (0.298 microgram/l, 95%-CI: [0.254, 0.335]).

CONCLUSIONS

All patients undergoing CABG surgery with or without extracorporeal circulation postoperatively showed an increase of cardiac troponin levels. After uncomplicated coronary revascularization, patients with the off-pump CABG technique continuously presented lower serum cardiac troponin concentrations than those with the on-pump CABG technique. CTnI showed the same patterns of release in both groups with different median postoperative peak values at 24 h. The patterns off cTnT release following CABC surgery with or without extracorporal circulation were different: CTnT reaches its postoperative peak value in patients with the off-pump CABG technique earlier than those with the on-pump CABG technique (12 h postoperatively versus 48 h).

Possible role of the vitamin E solubilizer in topical diclofenac on matrix metalloproteinase expression in corneal melting: an analysis of postoperative keratolysis

OBJECTIVE

To analyze tissue matrix metalloproteinase (MMP) expression in three patients who developed postoperative corneal melts after treatment with topical diclofenac sodium 0.1% (Falcon; Fort Worth, TX) ophthalmic solution.

DESIGN

Retrospective noncomparative interventional case series with tissue analysis.

MAIN OUTCOME MEASURES

Three patients were examined in this study. We report two patients from the same center with acute corneal melts after uncomplicated photorefractive keratectomy (PRK). Prior to these cases, 1500 patients were treated at the Zale Lipshy University Laser Center for Vision with no adverse effects. All 1500 patients were treated with the same postoperative regimen of ciprofloxacin, rimexolone, and suprofen ([Profenal, (CIBA, Duluth, GA]). The next 27 cases were treated postoperatively with ciprofloxacin and rimexolone. However, diclofenac sodium 0.1% was used instead of Profenal. A third case was also discussed. This melt occurred at another center in a postoperative cataract patient who developed cystoid macular edema after cataract extraction with intraocular lens placement. He was initially treated with diclofenac sodium 0.1% (Ciba Vision, Duluth, GA) then with diclofenac sodium 0.1%. He subsequently developed a corneal perforation requiring penetrating keratoplasty. All tissue specimens were examined by light microscopy. Microbiologic cultures and stains were also performed. Immunolocalization and in situ hybridization were performed on all keratoplasty specimens to detect expression and localization of MMPs. All patients had a complete diagnostic evaluation for systemic autoimmune diseases.

RESULTS

Postoperatively, all patients developed corneal perforations requiring surgical intervention while being treated with diclofenac sodium 0.1%. Microbiologic cultures and special stains were negative for microorganisms. Induced expression of specific tissue degrading enzymes of the matrix metalloproteinase family was demonstrated within corneal epithelial cells, stromal keratocytes, and at the level of Descemet's membrane. The uniform distribution pattern of expression was not consistent with the localization expected of a repair response, suggesting the involvement of some outside agent.

CONCLUSIONS

Whereas MMP expression is a normal component of repair, excessive or inappropriate MMP activity is associated with corneal keratolysis. Our study provides preliminary evidence that topical application of diclofenac sodium 0.1% may be associated with aberrant MMP expression in the cornea.

Matrix metalloproteinase (MMP-1) and tissue inhibitor of MMP in peritoneal fluids and sera and correlation with peritoneal adhesions

OBJECTIVE

To assess the presence of matrix metalloproteinase (MMP-1) and tissue inhibitor of MMP (TIMP-1) in peritoneal fluid and serum of subjects with and without adhesions.

DESIGN

Cross-sectional study.

SETTING

Academic research centers.

PATIENT(S)

Sixty-three patients who underwent abdominal/pelvic surgery.

INTERVENTION(S)

MMP-1, TIMP-1, and MMP-1-TIMP-1 complex content.

MAIN OUTCOME MEASURE(S)

ELISA.

RESULT(S)

Peritoneal fluids (PF) and sera of subjects with and without peritoneal adhesions contain MMP-1, TIMP-1, and MMP-1-TIMP-1 complex at varying levels with 10- to 100-fold higher TIMP-1 than MMP-1. Compared with serum, PF contains a lower level of MMP-1 in subjects with mild adhesions and without adhesions, higher TIMP-1 in subjects with extensive adhesions, and lower MMP-1-TIMP-1 complex in subjects with moderate adhesions. However, the serum and PF content of MMP-1, TIMP-1, and MMP-1-TIMP-1 complex was not statistically different among subjects with or without adhesions, with the exception of TIMP-1 in PF of subjects with extensive adhesions. MMP1-TIMP-1 ratio indicates that a major portion of MMP-1 is in complex with TIMP-1. There was no age- or gender-dependent difference in MMP-1 and TIMP-1 content in serum or PF.

CONCLUSION(S)

Despite differences in MMP-1 and TIMP-1 levels in serum and PF of subjects with extensive and moderate adhesions, there is no correlation between MMP-1 and TIMP-1, with the exception of higher TIMP-1 in PF of subjects with extensive adhesions.

Postoperative course of S-100B protein and neuron-specific enolase in patients after implantation of continuous and pulsatile flow LVADs

BACKGROUND

In the early post-operative period after implantation of a continuous flow left ventricular assist device (LVAD) a non-pulsatile flow occurs. We compared the post-operative time-courses of protein S-100B (S100B) and neuron-specific enolase (NSE) as biochemical markers of brain injury in patients after implantation of a continuous flow LVAD and patients receiving a pulsatile flow LVAD.

METHODS

Since 1998 the continuous flow DeBakey VAD has been implanted in 8 patients at our institution. For comparison purposes, a group of 7 consecutive patients in whom a pulsatile Novacor N100 LVAD was implanted were investigated. In both groups cardiopulmonary bypass (CPB) with cardiotomy suction was used. S100B and NSE were measured in serum pre-operatively, 4 hours after CPB, and on days 1, 3, 7, and 14 after implantation of the LVAD. A neurologic examination was performed pre-operatively and post-operatively on days 3 and 14.

RESULTS

No differences were found between groups in pre-operative characteristics. The analysis of variance with repeated measurements for S-100B and NSE showed significant time effects (p = 0.004, p = 0.009, respectively) but no group effects (p = 0.06, p = 0.26, respectively) and no interaction between groups and time (p = 0.12, p = 0.48, respectively). The pre-operative serum level of S100B was significantly higher (p = 0.03) in the DeBakey VAD group. The pre-operative serum level of NSE was similar in the 2 groups (p = 0.7). In both groups there was a significant increase of S100B and NSE immediately after surgery (S100B: p = 0.006, p = 0.019; NSE: p = 0.01, p = 0.001). The values returned to pre-operative levels in the DeBakey VAD group on day 1 after implantation and in the Novacor group for S100B on day 3 and NSE on day 1. Post-operatively the mean values of S100B and NSE in the DeBakey VAD group compared with the Novacor group were significantly elevated only on day 3 (p = 0.005, p = 0.023).No neurologic complications were noted in patients with a continuous flow LVAD, whereas in the pulsatile LVAD group 2 patients presented neurologic abnormalities during the study period.

CONCLUSIONS

The similar course of biochemical markers of brain damage in both groups may indicate that the non-pulsatile flow in the early post-operative period does not lead to increased brain injury or permeability of the brain blood barrier.Elevated levels of S100B and NSE in the post-operative period can be used as diagnostic markers of brain injury in patients after implantation of both types of LVAD.

Interplay between methylenetetrahydrofolate reductase gene polymorphism 677C-->T and serum folate levels in determining hyperhomocysteinemia in heart transplant recipients

BACKGROUND

Homocysteine metabolism is often impaired in heart transplant recipients, and increased total homocysteine plasma levels may constitute a risk factor for the development of heart allograft vascular disease. Although 677C-->T transition in methylenetetrahydrofolate reductase (MTHFR) is associated with increased homocysteine levels in the general population, it is unclear whether MTHFR polymorphism influences homocysteine metabolism after heart transplant.

METHODS

Homocysteine, serum folate, renal function, concentrations of cyclosporine and its metabolites, and MTHFR genotype were determined in 57 heart transplant recipients (age, 55 +/- 11 yr; 21% women; time from transplant, 48 +/- 42 months).

RESULTS

Forty nine percent of the study population presented with hyperhomocysteinemia. Homocysteine was 17.1 +/- 5.9 micromol/liter, 19.4 +/- 4.9 micromol/liter, and 26.3 +/- 14.2 micromol/liter for genotypes CC, CT, and TT, respectively (p = 0.028, Kruskal-Wallis test). At multivariate analysis, MTHFR genotype was independently associated with homocysteine (p = 0.005). When the study population was divided into 2 groups accordingly to serum folate levels (above/below the median value of 6.1 ng/ml), MTHFR genotype remained a significant predictor of homocysteine only in patients with low serum folate (p = 0.048).

CONCLUSIONS

This study demonstrates that hyperhomocysteinemia is frequent in heart transplant recipients and that the 677C-->T transition in the MTHFR gene independently and unfavorably influences homocysteine metabolism in this group of patients. Adequate folate intake may overcome genetic predisposition to hyperhomocysteinemia.

[Pre- and postoperative transaminase changes within the scope of gastric banding in morbid obesity]

20-30% of obese patients without concomitant liver disease show elevated liver tests (ALAT, ASAT, GGT) which are known to normalize after weight reduction. Little is known about the impact of gastric banding on elevated liver enzymes. We investigated the role of gastric banding on weight reduction and liver enzymes in a cohort of patients with morbid obesity. 198 obese patients (166 female, 32 male: median age 37 [19-65] years) with BMI 46 kg/m2 were assessed prior to gastric banding and 6/12 months postoperative for BMI, ALAT, ASAT, GGT respectively. Specific liver diseases were excluded. 37 patients (18.7%) had elevated liver enzymes (ALAT 14.1%, ASAT 9.6%, GGT 6.6%) preoperatively. ALAT and ASAT returned to normal in all patients postoperatively (p < 0.01). In 14 patients with significant ALAT-elevation (i.e. > 10% above normal) we found a correlation between postoperative fall of ALAT and reduction of BMI within 12 month (r = 0.4998; p < 0.05).

CONCLUSION

18.7% of morbid obese patients (BMI 46 kg/m2) have elevated liver enzymes prior to laparoscopic gastric banding. The normalisation of elevated liver enzymes correlates to the extent of weight reduction after gastric banding. Our data show reversible liver enzyme abnormalities, correlating to the degree of obesity.

Role of xanthine oxidase in small bowel mucosal dysfunction after surgical stress

BACKGROUND

The small intestine is highly susceptible to surgical stress even at remote locations. An earlier study using a rat model indicated that oxidative stress plays an important role in this process. The enzyme xanthine oxidase is an important source of free radicals in the small intestine. The role of this enzyme in intestinal damage after surgical stress was examined.

METHODS

Rats pretreated with xanthine oxidase inhibitors were subjected to surgical stress by opening the abdomen and handling the intestine, as done during laparotomy. Enterocytes at various stages of differentiation were isolated and the protection offered by xanthine oxidase inhibitors against damage due to surgical stress was determined and compared with normal controls. Protection against ultrastructural changes to the mucosa, as well as mitochondrial function was examined.

RESULTS

Surgical stress affected both the villus as well as crypt cells, causing increased superoxide generation, accompanied by increased activity of xanthine oxidase. Xanthine oxidase inhibitors ameliorated the increased superoxide generation, and protected against mitochondrial damage and ultrastructural changes in the intestine.

CONCLUSION

Surgical stress affects both the villus and crypt cell populations in the small intestine. The enzyme xanthine oxidase maybe an important mediator of surgical stress in the intestine.

Subtle brain damage cannot be detected by measuring neuron-specific enolase and S-100beta protein after carotid endarterectomy

OBJECTIVE

To assess whether subtle brain damage after carotid endarterectomy could be detected using serum levels of neuron-specific enolase (NSE) or S-100beta protein.

DESIGN

Prospective noninterventional study.

SETTING

University hospital.

PARTICIPANTS

Twenty-two patients undergoing carotid endarterectomy and 16 patients undergoing repair of abdominal aortic aneurysm.

INTERVENTIONS

Serum levels of NSE and S-100beta protein were measured in all patients before surgery and postoperatively at 12, 24, 36, and 48 hours. In patients undergoing carotid endarterectomy, neuropsychologic testing was performed before surgery and postoperatively at discharge from the hospital and after 3 months using a neuropsychologic test battery.

MEASUREMENTS AND MAIN RESULTS

Compared with abdominal aortic surgery patients, the preoperative serum concentration of NSE was significantly higher in carotid artery surgery patients. Postoperatively, the NSE serum level decreased significantly after uncomplicated carotid artery surgery, and the level was then similar to that in the aortic surgery patients. Before operation, the S-100beta protein levels were similar in the two groups, but a significant increase was seen in aortic surgery patients postoperatively. Neuropsychologic testing after uncomplicated carotid artery surgery revealed cognitive dysfunction in 2 of 20 (10%) of the patients after 5 days and 3 of 16 (19%) of the patients after 3 months. There was no correlation between the change in cognitive function and the changes in blood levels of either NSE or S-100 protein.

CONCLUSIONS

Subtle brain damage after carotid artery surgery could not be detected by measuring blood levels of NSE and S-100beta protein. The NSE level was significantly higher before carotid artery surgery and decreased postoperatively to the level observed in aortic surgery.

Surgical stress and the development of complications in relation to polymorphonuclear leukocyte elastase (PMNE) levels

This study was conducted to examine the effects of surgical stress on changes in polymorphonuclear leukocyte elastase (PMNE) levels, and to evaluate the relationship of these changes to the development of postoperative complication. A total of 69 patients who underwent alimentary surgery were subsequently divided into three groups: a complicated group, comprised of 25 patients; an uncomplicated group with a high blood loss (H) of more than 1000 ml, comprised of 18 patients; and an uncomplicated group with a low blood loss (L) of less than 1000 ml, comprised of 26 patients. The changes in the levels of PMNE, fibronectin (FN), and antithrombin III (AT III) were compared among these three groups. In the uncomplicated H and L groups the PMNE levels rose significantly on postoperative day (POD) 1. On POD 3, high levels of PMNE were still evident in the uncomplicated H group, but a decline was observed in the uncomplicated L group. From POD 7 onwards the levels decreased to the preoperative values in both uncomplicated groups; however, the complicated group continued to show high levels even on POD 14. Significantly decreased FN levels were observed for the first 3 PODs in each group. The uncomplicated H and L groups regained their preoperative levels on PODs 7 and 14, respectively, but no recovery was found in the complicated group. The AT III levels showed similar changes to the FN levels in all groups. These findings indicate that monitoring the PMNE levels could be a useful index for the early detection of postoperative complications following alimentary surgery.