Adhesion molecules as determinants of disease: from molecular biology to surgical research

Heme oxygenase‑1 improves the survival of ischemic skin flaps (Review)

Heat shock protein 32 (Hsp32), also known as heme oxygenase‑1 (HO‑1), is an enzyme that exists in microsomes. HO‑1 can be induced by a variety of stimuli, including heavy metals, heat shock, inflammatory stimuli, heme and its derivatives, stress, hypoxia, and biological hormones. HO‑1 is the rate‑limiting enzyme of heme catabolism, which splits heme into biliverdin, carbon monoxide (CO) and iron. The metabolites of HO‑1 have anti‑inflammatory and anti‑oxidant effects, and provide protection to the cardiovascular system and transplanted organs. This review summarizes the biological characteristics of HO‑1 and the functional significance of its products, and specifically elaborates on its protective effect on skin flaps. HO‑1 improves the survival rate of ischemic skin flaps through anti‑inflammatory, anti‑oxidant and vasodilatory effects of enzymatic reaction products. In particular, this review focuses on the role of carbon monoxide (CO), one of the primary metabolites of HO‑1, in flap survival and discusses the feasibility and existing challenges of HO‑1 in flap surgery.

Gene Expression of E-Selectin in Tissue and its Protein Level in Serum of Breast Cancer Patients

Aims and background

This study aims to detect the expression of E-selectin in tissue and the serum level of its soluble form in patients with primary breast cancer and benign breast tumors and to correlate the results with the clinicopathological data of the subjects.

Methods

Fifty participants were included in the study and stratified into 3 subgroups. Group A comprised 30 patients with primary breast cancer, group B 9 patients with benign breast tumors, and group C 11 healthy control women undergoing reduction mammoplasty. E-selectin gene expression was investigated in breast tissues by PCR techniques and soluble E-selectin was measured in sera by ELISA.

Results

The E-selectin gene was expressed in 73.3% of group A, 44.4% of group B and 9.1% of group C. It was expressed in 61.5% of patients with grade 2 breast cancer and in 82.4% of patients with grade 3 breast cancer. E-selectin gene expression was detected in 60%, 73.3% and 100% of patients with stage II, III and IV tumors, respectively. It was detected in 81.8% of patients with node-positive primary breast cancer and in 50% of patients with node-negative cancer. PCR in situ hybridization was done to locate the site of E-selectin expression. E-selectin was found on the membranes of peritumoral endothelial cells while it was not found on breast epithelial cells. Serum levels of soluble E-selectin were significantly elevated in group A compared to groups B and C ( P <0.001). They increased significantly with increasing breast cancer stage ( P <0.001) and were significantly higher in patients with lymph node involvement than in patients without node involvement ( P <0.001).

Conclusions

The studied marker showed associations with established prognostic parameters such as lymph node involvement and histological tumor grade. Further studies are needed to evaluate E-selectin as a possible target for antimetastat-ic therapy through modulation of the expression of the cell adhesion molecule. E-selectin can be regarded as a promising strategy in improving tumor therapy.

Identification of endothelial selectin as a potential prognostic marker in breast cancer

Endothelial selectin (ELAM1 or CD62E) has been previously reported as being associated with the prognosis of multiple types of cancer. However, its prognostic value in breast cancer (BC) remains unclear. The aim of the present study was to investigate the prognostic value of ELAM1 mRNA expression in BC tissue. The prognostic value of ELAM1 mRNA was assessed in patients with BC using the Kaplan-Meier plotter (KM-plot) database. The KM-plot generated updated ELAM1 mRNA expression data and survival analysis from a total of 3,951 patients with BC, gathered from 35 datasets. Low expression of ELAM1 mRNA was correlated with a poorer overall survival in 1,402 patients with BC followed for 20 years [hazard ratio (HR), 0.71; 95% confidence interval (CI), 0.57–0.88; log-rank P=0.0016]. Low expression of ELAM1 was also correlated with poorer relapse-free survival (HR, 0.69; 95% CI, 0.62–0.77; log-rank P=2.2e-11) in 3,951 patients and poorer distant metastasis-free survival (HR, 0.79; 95% CI, 0.65–0.96; log-rank P=0.02) in 1,746 patients with BC followed for 20 years. Results from the Metabolic gEne RApid visualizer database indicated that ELAM1 mRNA expression was elevated in normal tissue. The results of the present study suggest that ELAM1 mRNA is a potential prognostic and metastatic marker in patients with BC.

Inflammatory markers and IL-6 polymorphism in peripheral arterial disease with and without diabetes mellitus

Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis, recognized as an inflammatory disease of the vessel wall, probably accelerated by diabetes mellitus (DM). Elevated interleukin (IL)-6 levels have been associated with increased cardiovascular morbidity and a common polymorphism has been identified in the promoter region of the IL-6 gene. The aim of this prospective study was to investigate inflammatory mediators in PAD patients (±DM) and to investigate a possible relationship to the IL-6 gene polymorphism. Five groups of patients (DM, intermittent claudication ±DM, critical limb ischemia (CLI) ±DM) and a control group of 20 individuals each were included. Hemoglobin, high sensitive C-reactive protein (hsCRP), creatinine, blood lipids, white blood cells (WBC); CD11b/CD18; vascular cell adhesion molecule (sVCAM-1), intercellular adhesion molecule (sICAM-1), sE-selectin, sP-selectin; IL-6, IL-8, tumour necrosis factor (TNF)α, sTNFα-R1 and sTNFα-R2 were analysed. The IL-6 gene polymorphism was determined in all groups and also compared with 200 healthy controls from a larger study of blood donors. In a multiple regression analysis, adjusted for gender, smoking and age, the effect of CLI was significantly ( p < 0.05) associated with elevated levels of the WBC count, hsCRP, proinflammatory cytokines (IL-6, TNFα-R1-2) and endothelial (sICAM, sVCAM) and WBC (CD11b gran) markers. The effect of less advanced PAD (intermittent claudication) was related to an increased concentration of sVCAM-1 and the number of monocytes and granulocytes. DM or leg ulcers were not significantly related to any of the markers. No significant difference in frequency of the various IL-6 genotypes was found between the groups or when compared with the group of 200 blood donors ( p > 0.3). Activation of cytokines, endothelial cells and WBC was related to the Fontaine stage of PAD but not to the presence of DM or ulcers. No association was found between the polymorphism in the IL-6 promoter region and PAD.

The effect of therapeutic hypothermia after cardiopulmonary resuscitation on ICAM-1 and NSE levels in sudden cardiac arrest rabbits

PURPOSE

To assess the effects of hypothermia and normothermia treatments for sudden cardiac arrest (SCA) on brain injury recovery in rabbit models.

METHODS

Cardiopulmonary resuscitation (CPR) was implemented on apnea-induced SCA rabbit models. Fifty survived rabbits were then randomly received hypothermia (n = 25, 32-34°C) or normothermia treatment (n = 25, 39-39.5°C) for 12 hours. The expected body temperatures were achieved within the first two hours, maintained for ten hours and then rewarmed. The physiological parameters, neurologic function, and the levels of adhesion molecule ICAM-1 and neuron-specific enolase (NSE) were monitored.

RESULTS

Hypothermia-treated rabbits had lower heart rate when achieving hypothermia (p < 0.0001) and higher SjvO2 after hypothermia maintenance (p = 0.038). The hypothermia group achieved better brain recovery performance according to the neurological deficit grading scale. ICAM-1 and NSE levels in both serum and CSF of the hypothermia group were lower than the normothemia group (all p < 0.0001) during hypothermia maintenance.

CONCLUSION

Hypothermia treatment after CPR provides better outcome than normothermia treatment in SCA rabbits. Hypothermia can reduce the ICAM-1 and NSE levels in both serum and cerebrospinal fluid (CSF). This study supports the clinical implementation of hypothermia treatment for SCA and reveals that ICAM-1 and NSE are involved in the recovery of brain function after resuscitation.

What happened if various kinds of postconditioning working on the preconditioned ischemic skin flaps

Objective: Ischemic pre-conditioning and post-conditioning are useful manipulations to reduce the undesirable effects of ischemia-reperfusion skin flap each. But the impact of post-conditioning on the pre-conditioning skin flap is not manifested. Here we investigated the influence of ischemic post-conditioning in a preconditioned axial pattern skin flap model.

Method: We used the skin flap in 40 rabbits and divided them into 5 groups randomly. At first we induced the ischemic pre-conditioning of the flap which was applied by 2 periods of 15 minutes of ischemia/15 minutes of reperfusion cycle. Next post-conditioning was performed by 6 cycles of 10 seconds of repeated ischemia/reperfusion periods at different times of just after the reperfusion,5 minutes after the reperfusion,10 minutes after the reperfusion. The animals were allocated into 5 groups: group 1 (Ischemia Group); group 2: (Pre-conditioning Group); group 3: (Pre-conditioning+ Post-conditioning Group); group 4 (Pre-conditioning+ Post-conditioning 5 minutes later Group); group5 (Pre-conditioning+ Post-conditioning 10 minutes later). The neutrophil count was assessed with histologic analysis before the dissection of the skin flap. Flap viability was assessed 1 week after the operation, and surviving flap area was recorded as a percentage of the whole flap area. LSD test was used for statistical analysis among different groups to evaluate the effects of ischemic pre-conditioning against ischemia.

Result: Among the varying groups, the neutrophil count varied: Group 1 was50.12±5.91; Group 2, 30.00±2.00, and Group 3, 18.87±3; Group 4, 22.50±1.92; Group 5, 30.12±1.88.The mean± SD surviving areas of the flaps for groups 1, 2, 3, 4 and 5 were 31.76±4.59, 51.26±3.24,82.18±5.28,66.85±3.87 and 51.13±2.90 respectively. Spearman correlation analysis shows an increase relation between neutrophil count and flap survival rate in the different groups (P <0.05).

Conclusion: Ischemic post-conditioning has protective effect on ischemic preconditioned skin flaps, but the post-conditioning should be performed within 5 minutes after the end of ischemia.

A potential for granulocyte-colony stimulating factor for use as a prophylactic agent for heatstroke in rats

Heatstroke is a form of excessive hyperthermia associated with a systemic inflammatory response that leads to multi-organ dysfunction in which central nervous system disorders predominate. Herein we determined to ascertain whether heat-induced multi-organ dysfunction in rats could be attenuated by granulocyte-colony stimulating factor (G-CSF) preconditioning. Anesthetized rats were divided into 2 major groups and given vehicle solution (isotonic saline, 0.3 ml, subcutaneously) or G-CSF (50-200 μg/kg body weight in 0.3 ml normal saline, subcutaneously) daily and consecutively for 5 days before the start of thermal experiments. They were exposed to an ambient temperature of 43°C for 68 min to induce heatstroke. G-CSF preconditioning significantly prolonged the survival time in heatstroke rats in a dose-related way (82-98 min vs 127-243 min). The non-preconditioning heatstroke animals showed hyperthermia, arterial hypotension, increased serum levels of systemic inflammatory response molecules, increased hypothalamic apoptotic cell numbers as well as neuronal damage scores, and increased serum levels of renal and hepatic dysfunction indicators. These heatstroke syndromes could be significantly reduced by G-CSF preconditioning. Thus our results revealed a potential for G-CSF used as a prophylactic agent for heatstroke in rats.

Split-liver procedure and inflammatory response: improvement by pharmacological preconditioning

BACKGROUND

Final outcome of split-liver (SL) transplantation is impaired due to an increased rate of vascular complications and primary non-function. Herein, we hypothesized that an in situ split-liver procedure induces an inflammatory response and a deterioration of graft quality. We further studied whether graft quality can be improved by pharmacologic preconditioning.

MATERIAL AND METHODS

SL-procedure was performed in rats. One group (SL-HPP; n = 8) was pretreated according to a defined protocol [Homburg preconditioning protocol (HPP)], including pentoxyphylline, glycine, deferoxamine, N-acetylcysteine, erythropoietin, melatonin, and simvastatin. A second SL group (SL-Con; n = 8) received NaCl. Untreated non-SL served as controls (Sham; n = 8). Cytokines release, leukocyte invasion, endothelial activation and liver morphology were studied directly after liver harvest and after 8 h cold storage. Lung tissue was studied to determine remote injury.

RESULTS

The SL-procedure induced an increase of TNF-α concentration, intercellular-adhesion-molecule 1 (ICAM-1) expression, leukocytic-tissue infiltration and vacuolization. This was associated with an increased number of apoptotic hepatocytes. HPP reduced TNF-α release, ICAM-1 expression, the number of infiltrated leukocytes, as well as hepatocellular vacuolization and apoptosis. In lung tissue, the SL-procedure caused an increased IL-1 and IL-6 concentration and leukocyte infiltration.

CONCLUSIONS

HPP was capable of abrogating cytokine-mediated leukocytic response. Pharmacologic preconditioning of liver donors prevents the SL procedure-mediated inflammatory response, resulting in an improved graft quality.

Kynurenic acid attenuates multiorgan dysfunction in rats after heatstroke

AIM

To assess whether systemic delivery of kynurenic acid improves the outcomes of heatstroke in rats.

METHODS

Anesthetized rats were divided into 2 major groups and given vehicle solution (isotonic saline 0.3 mL/kg rat weight) or kynurenic acid (30-100 mg in 0.3 mL saline/kg) 4 h before the start of thermal experiments. They were exposed to an ambient temperature of 43 °C for 68 min to induce heatstroke. Another group of rats were exposed to room temperature (26 °C) and used as normothermic controls. Their core temperatures, mean arterial pressures, serum levels of systemic inflammatory response molecules, hypothalamic values of apoptotic cells and neuronal damage scores, and spleen, liver, kidney and lung values of apoptotic cells were determined.

RESULTS

The survival time values during heatstroke for vehicle-treated rats were decreased from the control values of 475-485 min to new values of 83-95 min. Treatment with KYNA (30-100 mg/kg, iv) 4 h before the start of heat stress significantly and dose-dependently decreased the survival time to new values of 152-356 min (P<0.05). Vehicle-treated heatstroke rats displayed hypotension, hypothalamic neuronal degeneration and apoptosis, increased serum levels of tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and interleukin-10 (IL-10), and spleen, liver, kidney, and lung apoptosis. KYNA preconditioning protected against hypotension but not hyperthermia and attenuated hypothalamic neuronal degeneration and apoptosis during heatstroke. KYNA preconditioning attenuated spleen, kidney, liver, and lung apoptosis and up-regulated serum IL-10 levels but down-regulated serum TNF-α and ICAM-1 levels during heatstroke.

CONCLUSION

Our results suggest that systemic delivery of kynurenic acid may attenuate multiorgan dysfunction in rats after heatstroke.

The value of E-cadherin/beta-catenin expression in imprints of NCSLC: relationship with clinicopathological factors

Metastasis is specific for malignant tumors and its control is one of the most important problems in the design of therapies for cancer patients. Loss or reduction of E-cadherin expression and/or beta-catenin expression plays a casual role in tumor progression and metastasis and is associated with poor prognosis. The purpose of the study is to investigate the expression of E-cadherin and beta-catenin and their significance as independent prognostic markers in imprints of resected nonsmall cell lung cancer (NSCLC). Imprint smears from 70 patients who underwent surgical lung resection for primary carcinoma were studied. As control group was used imprints of physiological tissues. Histologically 47 (67.1%) of the tumors were squamous cell carcinomas and 23 (32.9%) were adenocarcinomas. Tumors stage was I in 29 (41.4%), II in 13 (18.6%), III in 24 (34.3%) and IV in 4 (5.7%). Positive expression for E-cadherin was observed in 44.29% of malignant smears vs 85.71% for control group (P = 0.011). For beta-catenin, positive expression was observed in 42.86% malignant cases vs 85.71% for control group (P = 0.008). Positive expression of E-cadherin and beta-catenin was observed in moderate and well differentiated tumors (P < 0.0001 for both respectively). Positive E-cadherin and beta-catenin expression was observed in 70.6% and 76.5% of the cases with negative lymphnode metastasis (P < 0.0001 for both respectively). There was no statistically significant association between histological type, tumor stage, pleural invasion, tumor size (P > 0.05 for all) and E-cadherin/beta-catenin expression.Reduced E-cadherin or beta-catenin negative expression relates to dedifferentiation and progression of NSCLC.

Prophylactic uses of integrin CD18-βA peptide in a murine polymicrobial peritonitis model

AIM: To evaluate the prophylactic properties of integrin CD18-βA peptide in a murine model of abdominal polymicrobial peritonitis and sepsis.

METHODS: Bacterial sepsis was induced in Institute of Cancer Research (ICR) mice by cecal ligation and puncture (CLP) surgery. Inflicted mice were then injected with either sterile saline or CD18-βA peptide intraperitoneally at 2 h after surgery, and were sacrificed at 12 and 24 h after surgery. Blood samples were immediately collected, and analyzed for endotoxin activity and tumor necrosis factor (TNF)-α and interleukin (IL)-6. Lungs and liver were studied for CD45+ leukocyte and CD3 mRNA content. Pulmonary expression of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM) and E-selectin was also determined.

RESULTS: Intraperitoneal injection of CD18-βA peptide significantly suppressed circulating endotoxin activity (P < 0.01) at 24 h, as well as serum levels of TNF-α (P < 0.05 at 12 and 24 h) and IL-6 (P < 0.01 at 12 h, P < 0.05 at 24 h) in CLP-inflicted mice. CD18-βA peptide also abrogated leukocyte infiltration into liver and lungs as unveiled by reduced CD45+ leukocyte and CD3 mRNA contents. Furthermore, the peptide significantly reduced pulmonary expression of VCAM (P < 0.01 at 12 h, P < 0.001 at 24 h), E-selectin (P < 0.01 at 12 and 24 h), and ICAM-1 (P < 0.01 at 12 h, P < 0.001 at 24 h). These actions of CD18-βA peptide collectively protected septic mice against lethality (P < 0.01).

CONCLUSION: CD18-βA peptide is a potent endotoxin antagonist that can protect surgical patients against sepsis-associated lethality.

Uncoupling protein-2 deficient mice are not protected against warm ischemia/reperfusion injury of the liver

BACKGROUND

Uncoupling protein-2 (UCP2) might play an important role in mediating ischemia/reperfusion (I/R) injury due to its function in uncoupling of oxidative phosphorylation and in the proton leak-associated increase of reactive oxygen species (ROS) production. The aim of this study was to elucidate the role of UCP2 in hepatic I/R injury.

MATERIALS AND METHODS

UCP2 wild type and UCP2 deficient mice were subjected to I/R of the left liver lobe. Sham-operated animals without I/R served as controls. Intravital fluorescence microscopy was used for assessing postischemic microcirculatory dysfunction. Indicators of hepatic inflammatory response, oxidative stress, and bioenergetic status as well as histomorphology were investigated.

RESULTS

Under sham conditions UCP2-/-mice presented slightly but not significantly higher levels of hepatic ATP and energy charge than wild type mice. In addition, they exhibited higher systemic IL-6 levels and intrahepatic leukocyte adherence. After exposure to I/R, the extent of reperfusion injury did not differ between UCP2+/+ and UCP2-/-mice, as indicated by a comparable loss of sinusoidal perfusion, hepatic ATP, and energy charge levels, as well as rise of transaminases and disintegration of liver structures. Intrahepatic leukocyte adherence and plasma IL-6 levels of postischemic UCP2-/-mice still exceeded those of UCP2+/+mice.

CONCLUSIONS

UCP2 appears to be of minor relevance for the manifestation and extent of postischemic reperfusion injury in nondiseased livers with the increased ATP availability being counteracted by the higher pro-inflammatory IL-6 levels in UCP2 deficient mice.

Protection in rats with heatstroke: hyperbaric oxygen vs activated protein C therapy

The present study was attempted to evaluate the therapeutic effects of activated protein C and/or hyperbaric oxygen in an animal model of heatstroke. Sixty-eight minutes heat stress (43 degrees C) initiated, the anesthetized rats were randomized to several groups and administered: 1) no resuscitation (vehicle solution plus normabaric air, 2) intravenous activated protein C (1mg in 1ml of normal saline per kg of body weight), 3) hyperbaric oxygen (100% oxygen at 202kpa for 17min), and 4) intravenous activated protein C plus hyperbaric oxygen. Another group of rats exposed to room temperature (26 degrees C) was used as normothermic controls. Blood sampling was 0min, 70min, and 85min after heat stress initiated. When the vehicle-treated rats underwent heat exposure, their survival time values found were to be 19-25min. Resuscitation with activated protein C or hyperbaric oxygen significantly and equally improved survival during heatstroke (134-159min). As compared with those of activated protein C or hyperbaric oxygen alone, combined activated protein C and hyperbaric oxygen significantly had higher survival time values (277-347min). All vehicle-treated heatstroke animals displayed systemic response, hypercoagulable state, and hepatic and renal dysfunction. Combined activated protein C and hyperbaric oxygen therapy reduced these heatstroke reactions better than activated protein C or hyperbaric oxygen alone. The results indicate consequently, combined activated protein C and hyperbaric oxygen therapy heightens benefit in combating heatstroke reactions.

The hepatic microcirculation: mechanistic contributions and therapeutic targets in liver injury and repair

The complex functions of the liver in biosynthesis, metabolism, clearance, and host defense are tightly dependent on an adequate microcirculation. To guarantee hepatic homeostasis, this requires not only a sufficient nutritive perfusion and oxygen supply, but also a balanced vasomotor control and an appropriate cell-cell communication. Deteriorations of the hepatic homeostasis, as observed in ischemia/reperfusion, cold preservation and transplantation, septic organ failure, and hepatic resection-induced hyperperfusion, are associated with a high morbidity and mortality. During the last two decades, experimental studies have demonstrated that microcirculatory disorders are determinants for organ failure in these disease states. Disorders include 1) a dysregulation of the vasomotor control with a deterioration of the endothelin-nitric oxide balance, an arterial and sinusoidal constriction, and a shutdown of the microcirculation as well as 2) an overwhelming inflammatory response with microvascular leukocyte accumulation, platelet adherence, and Kupffer cell activation. Within the sequelae of events, proinflammatory mediators, such as reactive oxygen species and tumor necrosis factor-alpha, are the key players, causing the microvascular dysfunction and perfusion failure. This review covers the morphological and functional characterization of the hepatic microcirculation, the mechanistic contributions in surgical disease states, and the therapeutic targets to attenuate tissue injury and organ dysfunction. It also indicates future directions to translate the knowledge achieved from experimental studies into clinical practice. By this, the use of the recently introduced techniques to monitor the hepatic microcirculation in humans, such as near-infrared spectroscopy or orthogonal polarized spectral imaging, may allow an early initiation of treatment, which should benefit the final outcome of these critically ill patients.

Human umbilical cord blood cells protect against hypothalamic apoptosis and systemic inflammation response during heatstroke in rats

BACKGROUND

Intravenous administration of human umbilical cord blood cells (HUCBC) has been shown to improve heatstroke by reducing arterial hypotension as well as cerebral ischemia and damage in a rat model. To extend these findings, we assessed both hypothalamic neuronal apoptosis and systemic inflammatory responses in the presence of HUCBCs or vehicle medium immediately after initiation of heatstroke.

METHODS

Anesthetized rats, immediately after the initiation of heat stress, were divided into two groups and given either serum-free lymphocyte medium (0.3mL per rat, intravenously) or HUCBCs (5 x 10(6) in 0.3 mL serum-free lymphocyte medium, intravenously). Another group of rats were exposed to room temperature (26 degrees C) and used as normothermic controls. Heatstroke was induced by exposing the anesthetized rats to a high ambient temperature of 43 degrees C for 68 minutes.

RESULTS

After the onset of heatstroke, animals treated with serum-free lymphocyte medium displayed hyperthermia, hypotension, bradycardia, hypothalamic neuronal apoptosis and degeneration, and up-regulation of systemic inflammatory response molecules including serum tumor necrosis factor-alpha, soluble intercellular adhesion molecule-1 and E-selectin. Heatstroke-induced hypotension, bradycardia, hypothalamic neuronal apoptosis and degeneration, and increased systemic inflammatory response molecules were significantly inhibited by HUCBC treatment. Although heatstroke-induced hyperthermia was not affected by HUCBC treatment, the serum levels of the anti-inflammatory cytokine interleukin-10 were significantly increased by HUCBC therapy during hyperthermia.

CONCLUSIONS

These findings suggest that HUCBC transplantation may prevent the occurrence of heatstroke by reducing hypothalamic neuronal damage and the systemic inflammatory responses.

Short-term resuscitation of predamaged donor livers by brief machine perfusion: the influence of temperature

Short-term machine perfusion after liver retrieval from non-heart-beating donors has been considered a beneficial means to reverse deleterious priming of the predamaged organ. In this study, the possible impact of different temperatures during aerobic perfusion was addressed, focusing on liver metabolic functions, structural integrity, and vascular activation. Livers retrieved 30 minutes after cardiac arrest of male Wistar rats (200-300 g) were preserved with histidine-tryptophan-ketoglutarate (HTK) solution for 18 hours by simple cold storage (CS) or subjected to short-term resuscitation (STR) with oxygenated (pO(2) > 500 mm Hg) machine perfusion with HTK at 4 degrees C, 12 degrees C, or 22 degrees C for 2 hours with subsequent CS for 16 hours at 4 degrees C. Upon reperfusion in a normothermic perfusion circuit, STR significantly improved enzyme leakage (alanine aminotransferase, glutamate dehydrogenase) and metabolic recovery (tissue levels of ATP) providing best values at 12 degrees C or 22 degrees C. Moreover, a hugely increased gene expression of the adhesion molecule ICAM-1 as well as major histocompatibility complex (MHC) class II antigen was seen after CS, but significantly alleviated by STR at 4 degrees C or 12 degrees C. However, mRNA for both surface proteins rose significantly after STR at 22 degrees C compared with CS. In conclusion, STR by oxygenated perfusion is beneficial to the predamaged graft, facilitating later transportation and supervision of the graft compared with continuous machine preservation. However, increased perfusion temperature should be recommended only up to the limit of 12 degrees C to prevent overactivation of surface antigen expression.

Recombinant human activated protein C inhibits integrin-mediated neutrophil migration

Integrin-mediated cell migration is central to many biologic and pathologic processes. During inflammation, tissue injury results from excessive infiltration and sequestration of activated leukocytes. Recombinant human activated protein C (rhAPC) has been shown to protect patients with severe sepsis, although the mechanism underlying this protective effect remains unclear. Here, we show that rhAPC directly binds to beta(1) and beta(3) integrins and inhibits neutrophil migration, both in vitro and in vivo. We found that human APC possesses an Arg-Gly-Asp (RGD) sequence, which is critical for the inhibition. Mutation of this sequence abolished both integrin binding and inhibition of neutrophil migration. In addition, treatment of septic mice with a RGD peptide recapitulated the beneficial effects of rhAPC on survival. Thus, we conclude that leukocyte integrins are novel cellular receptors for rhAPC and the interaction decreases neutrophil recruitment into tissues, providing a potential mechanism by which rhAPC may protect against sepsis.

The inflammatory response to skeletal muscle injury: illuminating complexities

Injury of skeletal muscle, and especially mechanically induced damage such as contusion injury, frequently occurs in contact sports, as well as in accidental contact sports, such as hockey and squash. The large variations with regard to injury severity and affected muscle group, as well as non-specificity of reported symptoms, complicate research aimed at finding suitable treatments. Therefore, in order to increase the chances of finding a successful treatment, it is important to understand the underlying mechanisms inherent to this type of skeletal muscle injury and the cellular processes involved in muscle healing following a contusion injury. Arguably the most important of these processes is inflammation since it is a consistent and lasting response. The inflammatory response is dependent on two factors, namely the extent of actual physical damage and the degree of muscle vascularization at the time of injury. However, long-term anti-inflammatory treatment is not necessarily effective in promoting healing, as indicated by various studies on NSAID treatment. Because of the factors named earlier, human studies on the inflammatory response to contusion injury are limited, but several experimental animal models have been designed to study muscle damage and regeneration. The early recovery phase is characterized by the overlapping processes of inflammation and occurrence of secondary damage. Although neutrophil infiltration has been named as a contributor to the latter, no clear evidence exists to support this claim. Macrophages, although forming part of the inflammatory response, have been shown to have a role in recovery, rather than in exacerbating secondary damage. Several probable roles for this cell type in the second phase of recovery, involving resolution processes, have been identified and include the following: (i) phagocytosis to remove cellular debris; (ii) switching from a pro- to anti-inflammatory phenotype in regenerating muscle; (iii) preventing muscle cells from undergoing apoptosis; (iv) releasing factors to promote muscle precursor cell activation and growth; and (v) secretion of cytokines and growth factors to facilitate vascular and muscle fibre repair. These many different roles suggest that a single treatment with one specific target cell population (e.g. neutrophils, macrophages or satellite cells) may not be equally effective in all phases of the post-injury response. To find the optimal targeted, but time-course-dependent, treatments requires substantial further investigations. However, the techniques currently used to induce mechanical injury vary considerably in terms of invasiveness, tools used to induce injury, muscle group selected for injury and contractile status of the muscle, all of which have an influence on the immune and/or cytokine responses. This makes interpretation of the complex responses more difficult. After our review of the literature, we propose that a standardized non-invasive contusion injury is the ideal model for investigations into the immune responses to mechanical skeletal muscle injury. Despite its suitability as a model, the currently available literature with respect to the inflammatory response to injury using contusion models is largely inadequate. Therefore, it may be premature to investigate highly targeted therapies, which may ultimately prove more effective in decreasing athlete recovery time than current therapies that are either not phase-specific, or not administered in a phase-specific fashion.

Continuous intra-arterial application of substance P induces signs and symptoms of experimental complex regional pain syndrome (CRPS) such as edema, inflammation and mechanical pain but no thermal pain

Substance P is involved in nociception in both the peripheral nervous system and the CNS and has been documented to play a crucial role in the complex regional pain syndrome (CRPS). So far, however, most experimental animal models are restricted to the effect of neurokinin-1 receptor blockers to inhibit substance P and do not directly evaluate its action. Thus, this study was conducted to test the hypothesis that local application of substance P causes signs and symptoms of CRPS. For this purpose rats received a continuous infusion of either substance P or saline over 24 h delivered by a mini-osmotic pump connected to an intrafemoral catheter. Animals were analyzed at either day 1 (n=6, each group) or day 4 (n=5, each group) after start of infusion. Substance P application caused a significant and long-lasting decrease in paw withdrawal thresholds upon mechanical stimulation, while animals did not present with thermal allodynia at days 1 and 4 after onset of infusion. In addition, severe s.c. edema was observed in all animals receiving substance P. In vivo fluorescence microscopy of the extensor digitorum longus muscle of the affected hind paw revealed enhanced leukocyte-endothelial cell interaction with a significant rise in the number of leukocytes both rolling along and firmly adhering to the wall of postcapillary venules, while saline-exposed animals were free of this local inflammatory response. Muscle cell apoptosis, as assessed by in vivo bisbenzimide staining, terminal deoxynucleotidyl transferase nick end labeling analysis and caspase 3-cleavage, could not be observed in either of the animals. In summary, the present study indicates that substance P is responsible for neurogenic inflammation, including local cell response, edema formation and mechanical pain, while it seems not to contribute to the generation of thermal allodynia.

Pathomechanisms of Ischemia-Reperfusion Injury as the Basis for Novel Preventive Strategies: Is It Time for the Introduction of Pleiotropic Compounds?

Ischemia-reperfusion-associated tissue dysfunction and organ failure still represent major complications in transplantation surgery. The pathomechanisms involve microvascular perfusion failure, ie, no-reflow and tissue hypoxia despite reperfusion and reoxygenation. However, postischemic reperfusion also provokes an inflammatory response, ie, reflow paradox, with activation of macrophages, recruitment of leukocytes, and accumulation of platelets, involving surface adhesion molecules such as P-selectin, P-selectin glycoprotein ligand (PSGL)-1, Mac-1, and intercellular adhesion molecule (ICAM)-1. These inflammatory cells produce cytokines, chemokines, lipid mediators, and oxygen radicals, which all may contribute to the manifestation of injury, including apoptosis, necrosis, and necrapoptosis. Although specific inhibition of single mediators, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and oxygen radicals, or distinct molecules, such as P-selectin and ICAM-1, has been shown to be protective in the experimental setting, these single-agent antimediator and antimolecule approaches did not find their way into clinical practice. Clinically, University of Wisconsin (UW) solution for organ preservation is still the major milestone for prevention of ischemia- and reperfusion-associated injury. Characteristically, this treatment strategy does not represent an anti-single mediator approach, but exerts protection by influencing multiple pathways involved in hypoxic and inflammatory injury, potentially restoring the overall homeostasis. This type of pleiotropic action may also be achieved by single pharmacological compounds, such as statins, erythropoietin, hemoxygenase-1, and L-glycine. In recent experimental studies, these compounds have been shown to be effective to reduce post-ischemic-reperfusion injury, and, additionally, to be associated with less side effects. Accordingly, these pleiotropic substances may represent ideal candidates for pharmacological preconditioning in patient treatment, and, thus, should be further evaluated in clinical trials.

Carboxypeptidase-B activation peptide, a marker of pancreatic acinar injury, but not L-selectin, a marker of neutrophil activation, predicts severity of acute pancreatitis

BACKGROUND

Severity prediction is difficult early in the course of acute pancreatitis. Markers of pancreatic injury, or inflammatory activation are candidate markers of severity. The aim of the present study was to assess predictive abilities of carboxypeptidase-B activation peptide (CAPAP-B) and soluble L-selectin (sL-selectin) using samples collected on admission to hospital.

METHODS

Patients with acute pancreatitis and disease (acute abdomen) and normal controls were studied. Samples were collected at admission and daily for 5 days. There were significant differences between mild and severe pancreatitis in urinary and plasma CAPAP-B on admission, C-reactive protein on day 3 and acute physiology and chronic health evaluation (APACHE)-II scores. Prediction of severity with CAPAP-B on admission was as good as with APACHE-II score after 48 h. Carboxypeptidase-B activation peptide was not raised in disease controls. By contrast, sL-selectin was lowered in all cases of acute pancreatitis, and in disease controls. There was no difference between mild and severe pancreatitis.

CONCLUSION

Urinary CAPAP-B, a marker of acinar injury, can be used to predict severity of acute pancreatitis at the time of admission to hospital, but sL-selectin has no value in this regard. The extent of acinar injury may be a more important early marker of severity than markers of inflammatory activation.

Systematic reviews and meta-analysis for the surgeon scientist

BACKGROUND

Understanding of data-reporting methods is imperative for correct interpretation of the medical literature as well as for proper performance of future clinical research. Recent developments in biostatistics have greatly changed the types of statistical analyses used and the minimum quality standards that must be maintained.

METHOD

Different types of review are described, including systematic review with and without meta-analysis. Minimum reporting standards, sources of bias, both quantitative and qualitative, and references are discussed.

RESULTS AND CONCLUSION

Meta-analysis has become a clearly defined technique, with reporting standards for both randomized controlled trials and observational studies. It is assuming a wider role in the surgical literature. Although many sources of bias exist, there are clear reporting standards and readers should be aware of these when studying the literature.

Endoplasmic and vascular surface activation during organ preservation: refining upon the benefits of machine perfusion

The endoplasmic reticulum (ER) represents a subcellular target reactive to various cytosolic impairments. The involvement of ER-stress in organ preservation was investigated, comparing machine preservation, cold storage (CS) and a novel concept of only temporary perfusion after procurement. Rat livers were retrieved 30 min after cardiac arrest and preserved for 18 h by CS, oxygenated machine perfusion for 18 h (18 h MP) or for 2 h with subsequent CS for 16 h (2 h MP + 16 h CS). Upon reperfusion, 18 h MP significantly improved enzyme leakage (ALT, LDH) and promoted a 2-fold increase of metabolic recovery compared to CS. However, vascular stress, evaluated by endothelin-release, was significantly elevated after 18 h MP. Interestingly, better viability was obtained using the short-term perfusion protocol (2 h MP + 16 h CS), which further reduced enzyme leakage, maintained energetic recovery and mitigated endothelin-release compared to 18 h MP. Caspase 12-mRNA was upregulated in the 18 h MP-group but unchanged after CS or 2 h MP + 16 h CS. Activation/cleavage of caspase 12 protein was significantly enhanced after 18 h MP and very low in the 2 h MP + 16 h CS-group. Correspondingly, electron microscopy showed ultrastructural alterations of ER after CS and especially after 18 h MP but not after 2 h MP + 16 h CS. At this time mitochondrial appearance was unaffected in all groups, suggesting the ER to be an early subcellular target of preservation injury. In our model, ER and vascular endothelium were best protected by only temporary machine perfusion, which also maintained overall graft viability.

Short-term microvascular response of striated muscle to cp-Ti, Ti-6Al-4V, and Ti-6Al-7Nb

Due to excellent mechanical properties and good corrosion resistance, titanium-aluminium-vanadium (Ti-6Al-4V) and titanium-aluminium-niobium (Ti-6Al-7Nb) are extensively used for orthopedic surgery. Concern has been voiced concerning the implications of the constituent vanadium in Ti-6Al-4V on the surrounding environment. Particularly in osteosynthesis where the alloys stand in direct contact to skeletal muscle, undesirable biologic reactions may have severe consequences. In a comparative study, we assessed in vivo nutritive perfusion and leukocytic response of striated muscle to the metals Ti-6Al-4V, Ti-6Al-7Nb, and commercially pure titanium (cpTi), thereby drawing conclusions on their short-term inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we quantified primary and secondary leukocyte-endothelial cell interaction, leukocyte extravasation, microvascular diameter change, and capillary perfusion in collecting and postcapillary venules of skeletal muscle. A manifest discrepancy between the metals concerning impact on local microvascular parameters was not found. All metals induced an only transient and moderate inflammatory response. Only a slight increase in leukocyte recruitment and a more sluggish recuperation of inflammatory parameters in animals treated with Ti-6Al-4V compared to the other two metals suggested a minor, overall not significant discrepancy in biocompatibility. Gross toxicity of bulk Ti-6Al-4V on surrounding tissue could not be found. Conclusively, the commonly used biomaterials Ti-6Al-4V, Ti-6Al-7Nb, and cpTi induce an only transient inflammatory answer of the skeletal muscle microvascular system. Our results indicate that on the microvascular level the tested bulk Ti-alloys and cpTi do not cause adverse biologic reactions in striated muscle.

The effects of moderate hypothermia on energy metabolism and serum inflammatory markers during laparotomy

The objective of this study was to investigate energy metabolism of the gut and liver as well as serum inflammatory cytokines following exploratory laparotomy at moderate hypothermia. Two groups of rats were studied, (n=6-8/group); laparotomy at normothermia for 120 min and laparotomy at hypothermia (32-33 degrees C) for 120 min. Study 1: Intestinal glucose, succinate, lactate, phosphocreatine, and ATP as well as hepatic glucose, succinate, lactate, and ATP were measured in terms of micromole per gram using magnetic resonance spectroscopy. Study 2: Serum levels of TNF-alpha, IL-1beta, LPS-inducible chemokine (LIX), and sICAM-1 were measured by ELISA. Histology of the gut and liver were interpreted. Data are expressed as mean and SEM. In Study 1, laparotomy at hypothermia caused an increase in intestinal glucose levels (0.78+/-0.03 vs. 1.29+/-0.11, P=0.0012) with a decrease in hepatic lactate levels (0.82+/-0.04 vs. 0.44+/-0.06, P<0.001). There were no differences in the other metabolites between the two groups. In Study 2, there were no differences in serum TNF-alpha, IL-1beta, LIX, or sICAM-1 between the two groups. Histological features of the gut and liver among groups were comparable. In conclusion, the intestine and liver react to hypothermia differently. However, levels of high-energy phosphates in both organs are not affected by hypothermia suggesting adequate energy for the organs. It is unlikely that hypothermia induces either systemic inflammatory response or hypoxic damage to the intestine and liver in this model.

Amelioration of intestinal reperfusion injury by moderate hypothermia is associated with serum sICAM-1 levels

BACKGROUND

The aim of this study was to investigate the effects of moderate hypothermia on various serum markers involving in inflammation after intestinal ischemia-reperfusion (IR).

MATERIALS AND METHODS

The model of 30 min intestinal ischemia +90 min reperfusion was used. Three groups of rats were studied, n=7-8 per group: 1) sham at normothermia, 36.5 to 37.5 degrees C; 2) IR at normothermia and; 3) IR at moderate hypothermia, 32 to 33 degrees C. Serum levels of TNF-alpha, lipopolysaccharide-inducible CXC chemokine (LIX), and soluble intercellular adhesion molecule-1 (sICAM-1) were determined using ELISA technique. Histological features of terminal ileum were also graded.

RESULTS

Intestinal IR at normothermia caused remarkable tissue injury together with an elevation in serum TNF-alpha, LIX, and sICAM-1 levels. Moderate hypothermia significantly decreased the degree of mucosal damage and attenuated the elevation of serum sICAM-1 levels. However, there were no significant differences in serum TNF-alpha and LIX levels between IR at normothermia and IR at hypothermia.

CONCLUSIONS

Intestinal IR at normothermia induces the elevation of serum TNF-alpha, LIX, and sICAM-1 levels. Moderate hypothermia protects the small intestine from reperfusion injury. This beneficial effect is associated with serum sICAM-1 levels but not with serum TNF-alpha and LIX levels. We speculate that one of the mechanisms, by which hypothermia blunts the tissue injury, is at the step of firm adhesion between leukocytes and endothelial cells.

Intercellular adhesion molecule (ICAM-1) response after major neonatal surgery

Surgical stress induces systemic endocrine-metabolic responses that influence the function of endothelial cells (EC) to cause various systemic reactions. Intercellular adhesion molecule (ICAM)-1 is an adhesion molecule that plays an important role in inflammation, and increased expression of ICAM-1 on EC is a reflection of EC activation. In this study, we investigated the ICAM-1 response to surgical stress in neonates undergoing major surgery. Fifteen neonates (mean age at surgery: 3.5 +/- 1.2 days) were divided into two groups according to indications for surgery: Group I: Congenital diaphragmatic hernia without persistent pulmonary hypertension (n = 5); Group II: Gastrointestinal surgery [n = 10: duodenal atresia (n = 3), intestinal atresia (n = 6), and esophageal atresia (n = 1)]. Serum samples were obtained preoperatively, immediately after completion of surgery (time zero), and 24, 48, 72, 96, and 120 h after surgery to measure ICAM-1 levels using an enzyme-linked immunosorbent assay, C-reactive protein (CRP), and white blood cell count (WBC). Postoperative recovery was uneventful in all cases. ICAM-1 levels in both groups increased significantly within 24 h of surgery (Group I: P = 0.0038, Group II: P = 0.0320). In Group I, ICAM-1 peaked 72 h postoperatively while in Group II it continued to rise until 96 h postoperatively. The difference between peak levels reached was not significant. CRP was first detected 24 h postoperatively in both groups and continued to increase until 48 h postoperatively. Again, the difference between peak levels reached was not significant. No significant changes in WBC were observed in either group. We found that ICAM-1 increases in response to surgical stress in neonates, although there was no significant difference in levels. However, surgical stress as represented by serum ICAM-1 would appear to last longer with intestinal surgery than with non-intestinal surgery. Further research is required to establish the usefulness of ICAM-1 as an easily detectable substance associated with endothelial damage that reflects the host's response to major surgical stress.

Mechanisms of Focal Heat Destruction of Liver Tumors

BACKGROUND

Focal heat destruction has emerged as an effective treatment strategy in selected patients with malignant liver tumors. Radiofrequency ablation, interstitial laser thermotherapy, and microwave treatment are currently the most widely applied thermal ablative techniques. A major limitation of these therapies is incomplete tumor destruction and overall high recurrences. An understanding of the mechanisms of tissue injury induced by focal hyperthermia is essential to ensure more complete tumor destruction. Here, the currently available scientific literature concerning the underlying mechanisms involved in the destruction of liver tumors by focal hyperthermia is reviewed.

METHODS

Medline was searched from 1960 to 2004 for literature regarding the use of focal hyperthermia for the treatment of liver tumors. All relevant literature was searched for further references.

RESULTS

Experimental evidence suggests that focal hyperthermic injury occurs in two distinct phases. The first phase results in direct heat injury that is determined by the total thermal energy applied, tumor biology, and the tumor microenvironment. Tumors are more susceptible to heat injury than normal cells as the result of specific biological features, reduced heat dissipating ability, and lower interstitial pH. The second phase of hyperthermic injury is indirect tissue damage that produces a progression of tissue injury after the cessation of the initial heat stimulus. This progressive injury may involve a balance of several factors, including apoptosis, microvascular damage, ischemia-reperfusion injury, Kupffer cell activation, altered cytokine expression, and alterations in the immune response. Blood flow modulation and administration of thermosensitizing agents are two methods currently used to increase the extent of direct thermal injury. The processes involved in the progression of thermal injury and therapies that may potentially modulate them remain poorly understood.

CONCLUSION

Focal hyperthermia for the treatment of liver tumors involves complex mechanisms. Evidence suggests that focal hyperthermia produces both direct and indirect tissue injury by differing underlying processes. Methods to enhance the effects of treatment to achieve complete tumor destruction should focus on manipulating these processes.

Expression of cell adhesion molecules in oesophageal carcinoma and its prognostic value

Oesophageal carcinoma remains a disease of poor prognosis. Surgical cure rates are compromised by the fact that most patients are diagnosed at a late stage of disease because of the delayed onset of symptoms, by which time metastases and organ infiltration may have already occurred. Thus, invasion and metastases play a key role in influencing patient survival, and the search for novel treatments may therefore hinge on gaining insight into the mechanisms controlling these processes. It has been established that the initial step in the metastatic cascade is the detachment of tumour cells from the primary tumour via dysregulation of normal cell-cell and cell-matrix interactions. Distinct proteins known as cell adhesion molecules (CAMs) mediate these interactions. In recent years, a plethora of information has contributed to the in depth understanding of these molecules. This review provides a brief description of five families of CAMs (cadherins, integrins, CD44, immunoglobulin superfamily, and selectins) and highlights their altered expression in relation both to prognosis and tumour behaviour in squamous cell carcinoma and adenocarcinoma of the oesophagus.

Microvascular response of striated muscle to common arthroplasty-alloys: A comparativein vivo study with CoCrMo, Ti-6Al-4V, and Ti-6Al-7Nb

The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. Due to excellent physical and corrosion characteristics, CoCrMo-, Ti-6Al-4V-, and Ti-6Al-7Nb-alloys are commonly used in orthopedic surgery. Yet concern has been raised with regard to the implications of inevitable corrosion product of these metals on the surrounding biologic environment, particularly in the case of CoCrMo. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to these alloys, thereby drawing conclusions on their inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that the implant material CoCrMo has a marked impact on local microvascular parameters. While the Ti-alloys Ti-6Al-4V and Ti-6Al-7Nb induced only a transient and moderate inflammatory response, the implantation of a CoCrMo sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity and marked leukocyte extravasation. Animals with Ti-alloys showed a clear tendency of recuperation, while in all but one CoCrMo-treated animals, a breakdown of microcirculation prior to the scheduled end of the experiment was observed. Overall, the alloy Ti-6Al-7Nb was tolerated slightly better than Ti-6Al-4V under the chosen test conditions, though this discrepancy was not statistically significant. Conclusively, the commonly used biomaterials Ti-6Al-7Nb and Ti-6Al-4V induce a considerably lower inflammatory response in the skeletal muscle microvascular system, compared to a CoCrMo-alloy. With a minimum of adverse host reaction, our results indicate that for this particular model Ti-alloys are better tolerated than CoCrMo implant materials.

Surgical trauma: hyperinflammation versus immunosuppression?

BACKGROUND

Experimental and clinical studies have brought evidence that surgical trauma markedly affects the immune system, including both the specific and the non-specific immune response.

MATERIALS AND METHODS

This report reviews the present knowledge on the mechanisms of surgical trauma-induced immune dysfunction and outlines experimental and clinical approaches to find effective treatment strategies.

RESULTS

Major surgical trauma induces an early hyperinflammatory response, which is characterized by (1) pro-inflammatory tumour necrosis factor alpha (TNF), interleukin (IL)-1, and IL-6 cytokine release and (2) neutrophil activation and microvascular adherence, as well as (3) uncontrolled polymorphonuclear (PMN) and macrophage oxidative burst. The massive and continuous IL-6 release induces an acute phase response, but, more importantly, also accounts for the up-regulation of major anti-inflammatory mediators, such as prostaglandin (PG) E2, IL-10 and transforming growth factor (TGF)-ss. This results in surgical, trauma-induced, immunosuppression, as indicated by (1) monocyte deactivation, reflected by the lack of monocytic TNF- production upon lipopolysaccharide (LPS) stimulation, and (2) a shift of the Th1/Th2 ratio towards a Th2-dominated cytokine pattern. The imbalance between pro-inflammatory and anti-inflammatory cytokines and immuno-competent cells determines the phenotype of disease and should help the physician to compose the therapeutic strategy. In fact, recent clinical studies have shown that both the initial uncontrolled hyperinflammation and the continued cell-mediated immunosuppression represent primary targets to counteract post-surgery immune dysfunction. The balance between inflammatory and anti-inflammatory forces may be restored by interferon gamma (IFN-gamma) to counteract monocyte deactivation; the anti-inflammatory PGE2 may be inhibited by indomethacin to attenuate immunosuppression; or the initial hyperinflammation may be targeted by administration of anti-inflammatory substances, such as granulocyte colony-stimulating factor (G-CSF), hydoxyethyl starch, or pentoxifylline.

CONCLUSIONS

When drawing up the therapeutic regimen the physician should not consider hyperinflammation versus immunosuppression, but hyperinflammation and immunosuppression, aiming at restoring an appropriate mediator- and immune cell-associated balance.

Different faces of the heme-heme oxygenase system in inflammation

The heme-heme oxygenase system has recently been recognized to possess important regulatory properties. It is tightly involved in both physiological as well as pathophysiological processes, such as cytoprotection, apoptosis, and inflammation. Heme functions as a double-edged sword. In moderate quantities and bound to protein, it forms an essential element for various biological processes, but when unleashed in large amounts, it can become toxic by mediating oxidative stress and inflammation. The effect of this free heme on the vascular system is determined by extracellular factors, such as hemoglobin/heme-binding proteins, haptoglobin, albumin, and hemopexin, and intracellular factors, including heme oxygenases and ferritin. Heme oxygenase (HO) enzyme activity results in the degradation of heme and the production of iron, carbon monoxide, and biliverdin. All these heme-degradation products are potentially toxic, but may also provide strong cytoprotection, depending on the generated amounts and the microenvironment. Pre-induction of HO activity has been demonstrated to ameliorate inflammation and mediate potent resistance to oxidative injury. A better understanding of the complex heme-heme

The prognostic value of circulating soluble cell adhesion molecules in patients with chronic congestive heart failure

BACKGROUND

Circulating soluble (s) cell adhesion molecules (CAMs) are elevated in patients with congestive heart failure (CHF) and may play an important role in the pathogenesis of CHF by mediating the cell-cell interactions of the immune response. However, clinical data about the prognostic value of sCAMs are sparse. The purpose of this study is to determine whether various sCAMs can provide prognostic information in patients with CHF.

METHODS

We measured circulating levels of three sCAMs (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and sP-selectin) in 74 patients with symptomatic chronic CHF and left ventricular ejection fraction (LVEF) <50%. We compared these levels with those of a group of 19 age-matched control subjects. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening CHF) during a median follow-up period of 240 days were determined.

RESULTS

The concentrations of the three sCAMs in the 74 patients with CHF were significantly associated with one another. Their levels were higher than those of the control subjects and increased with the severity of CHF. Significantly higher sCAM levels were noted in those patients who had major adverse cardiac events during the follow-up period. There were significant negative correlations between LVEF and sCAMs. However, only high levels of sP-selectin were found to be an independent significant predictor of CHF by Cox proportional hazards analysis.

CONCLUSIONS

These findings indicate that the levels of these three sCAMs increase with the severity of CHF and are related to clinical outcomes. Among them, high levels of sP-selectin can provide prognostic information independently in patients with CHF.

Multistep nature of microvascular recruitment of ex vivo-expanded embryonic endothelial progenitor cells during tumor angiogenesis

Tissue neovascularization involves recruitment of circulating endothelial progenitor cells that originate in the bone marrow. Here, we show that a class of embryonic endothelial progenitor cells (Tie-2+, c-Kit+, Sca-1+, and Flk-1-/low), which were isolated at E7.5 of mouse development at the onset of vasculogenesis, retain their ability to contribute to tumor angiogenesis in the adult. Using intravital fluorescence videomicroscopy, we further defined the multistep process of embryonic endothelial progenitor cell (eEPC) homing and incorporation. Circulating eEPCs are specifically arrested in "hot spots" within the tumor microvasculature, extravasate into the interstitium, form multicellular clusters, and incorporate into functional vascular networks. Expression analysis and in vivo blocking experiments provide evidence that the initial cell arrest of eEPC homing is mediated by E- and P-selectin and P-selectin glycoprotein ligand 1. This paper provides the first in vivo insights into the mechanisms of endothelial progenitor cell recruitment and, thus, indicates novel ways to interfere with pathological neovascularization.

Oxygenated machine perfusion mitigates surface antigen expression and improves preservation of predamaged donor livers

The aim of the present study was to evaluate the potential benefit of machine preservation with the Belzer MPS or HTK solution, compared to standard cold storage, after procurement of marginal livers from non-heart beating donors in an experimental pilot study. Livers from male Wistar rats (250-300 g bw) were harvested after 60 min of cardiac arrest, flushed via the portal vein and cold stored submerged in HTK for 24 h at 4 degrees C while other organs were subjected to oxygenated machine perfusion with HTK or Belzer's MPS at 5 ml/min at 4 degrees C. Cold perfusion of livers with the non-colloidal HTK was not compromised by the lack of oncotic agents and there was no rise in vascular resistance during the 24 h of machine preservation with HTK or the colloidal Belzer MPS. Viability of the livers was assessed after the cold preservation period by warm reperfusion in vitro. Oxygenated machine perfusion was found to significantly increase viability of the livers vs simple cold storage with respect to portal vascular resistance upon reperfusion, enzyme release as well as functional recovery of oxygen utilization or bile production. Moreover, tissue antigen expression of ICAM-1 or histocompatibility antigen class II could be markedly reduced by oxygenated perfusion preservation as compared to cold storage. It is concluded that predamaged organs should preferably be preserved by oxygenated machine perfusion thus minimizing functional alterations and immunogenicity of the graft. In this setup HTK appeared equally effective as Belzer's MPS for machine preservation.

Soluble adhesion molecules (E-selectin, ICAM-1 and VCAM-1) in breast carcinoma

Adhesion molecules are important in cell-cell and cell-basement membrane interactions. They are intimately involved in inflammatory reactions and a role in tumour progression has been postulated. E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) play a role in cell adhesion to the vascular endothelium, and may have a role in tumour cell dissemination. Soluble forms of these molecules have been described and this study was established to examine these adhesion molecules in patients with breast carcinoma. Serum was obtained from 92 patients with breast carcinoma and 31 age-matched patients with benign breast disease. All samples were obtained prior to surgery. Soluble levels of E-selectin, ICAM-1, and VCAM-1 were significantly elevated in patients with Stage 4 disease compared with controls. (E-selectin 88.6 (47.9) versus 51.4 (18.4) ng/ml; P<0.001: ICAM-1 447 (249) versus 244 (79) ng/ml; P<0.001: VCAM-1 779 (159) versus 552 (135) ng/ml; P<0.001 results expressed on mean (SEM) SD placed above this.). The prognostic value of the adhesion molecules was examined. In patients with Stage 2 disease, elevated VCAM-1 was predictive of decreased survival, even when corrected for T and N status. Adhesion molecules are elevated in patients with advanced disease and elevation in VCAM-1 has prognostic significance in patients with breast carcinoma.

Endothelial cell expression of adhesion molecules is induced by fetal plasma from pregnancies with umbilical placental vascular disease

OBJECTIVE

To test the hypothesis that local production with spill into the fetal circulation of factor(s) injurious to endothelium is responsible for the vascular pathology present when the umbilical artery Doppler study is abnormal. Expression of adhesion molecules is a feature of endothelial cell activation.

DESIGN

Case-control study.

SETTING

University teaching hospital.

SAMPLES

Fetal plasma was collected from 27 normal pregnancies, 39 pregnancies with umbilical placental vascular disease defined by abnormal umbilical artery Doppler and 11 pregnancies with pre-eclampsia and normal umbilical artery Doppler.

METHODS

Isolated and cultured human umbilical vein endothelial cells from normal pregnancies were incubated with fetal plasma from three study groups. mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were assessed by reverse transcription-polymerase chain reaction. To confirm the occurrence of this in vivo, we measured the levels of soluble fractions of sICAM-1, sVCAM-1 and sPECAM-1 in the fetal circulation in the fetal plasma used for endothelial cell incubation.

RESULTS

The mRNA expression of ICAM-1 [median 1.1 (interquartile range 0.5-1.9) vs 0.7 (0.3-1.2), P < 0.05] and PECAM-1 [2.1 (1.2-3.0) vs 1.5 (0.7-2.1), P < 0.05] was significantly higher following incubation with fetal plasma from umbilical placental vascular disease compared with the normal group. There was no difference in the expression of VCAM-1 [1.2 (0.9-1.8) vs 1.1 (0.8-1.6), ns]. The group with maternal pre-eclampsia and normal umbilical artery Doppler did not differ from the normal group. In the umbilical placental vascular disease group, the results were similar in the presence or absence of pre-eclampsia. For soluble fractions of the adhesion molecules released into the fetal circulation, we found the levels (ng/mL) of sICAM- I [median 248.5 (interquartile range 197.3-315.7) vs 174.2 (144.5-212.9), P < 0.05] and sPECAM-1 [9.3 (6.2-11.1) vs 6.1 (5.4-7.7), P < 0.05] in fetal plasma to be significantly increased in the presence of umbilical placental vascular disease compared with the normal.

CONCLUSIONS

Vascular disease in the fetal umbilical placental circulation is associated with an elevation in mRNA expression by endothelial cells of ICAM-1 and PECAM-1. Our study provides evidence for endothelial cell activation and dysfunction in umbilical placental vascular disease. We speculate that the plasma factor(s) affecting the vessels of the umbilical villous tree is locally released by the trophoblast. The occurrence of the maternal syndrome of pre-eclampsia appears to be independent of this.

Microvascular responses to sepsis: clinical significance

Sepsis can be defined as a phenomenon related to the host's response to infection. Sepsis is considered an uncontrolled, unregulated, and self-sustaining intravascular inflammation, resulting from an imbalance between systemic proinflammatory reaction and excessive anti-inflammatory response. Microcirculatory dysfunction lies at the center of sepsis pathogenesis and involves all three elements of the microcirculation: arterioles, capillaries, and venules. Endothelium plays a pivotal role in the pathogenesis of sepsis, not only because it modulates the inflammatory response but also because endothelial cells activated with excessive amounts of inflammatory mediators become dysfunctional. In response to various stimuli, the endothelium exhibits a wide range of responses that may lead to local as well as systemic changes, giving rise to the phenotypic heterogeneity seen in sepsis. Therapeutic approaches, such as targeting the coagulation system, nitric oxide synthesis or intracellular signal transduction, have been considered. The administration of activated protein C has been associated with a dramatic reduction in mortality and ongoing studies with tissue factor pathway inhibitor seem promising. Glucocorticoids also seem promising for use in sepsis as a result of their anti-inflammatory effects.

The E-cadherin cell-cell adhesion complex and lung cancer invasion, metastasis, and prognosis

BACKGROUND

Lung cancer is the most common cause of cancer deaths in the western world. Progress in treatment results has been limited, and the prognosis is poor with a 5-year survival less than 15%. Based on new developments in molecular biology, our knowledge about lung carcinogenesis and mechanisms for invasion and metastasis has expanded and may in the future lead to more specific targeted therapies and better prognosis. The E-cadherin-catenin complex is critical for intercellular adhesiveness and maintenance of normal and malignant tissue architecture. Reduced expression of this complex in malignant disease is associated with tumour invasion, metastasis, and unfavorable prognosis.

METHODS

This review is based on search in the Medline database from 1991 to 2001. We have reviewed the relevance of the E-cadherin-catenin adhesion complex in malignancy in general and lung cancer in particular. Furthermore, its role as target for specific therapy is discussed.

RESULTS

Available data indicate that alterations of proteins involved in the E-cadherin-catenin complex are early incidents in cancer development. Reduced or altered expression of one or more of the components in this complex is associated with extended invasive and progressive behavior of cancer cells. Consistently, the E-cadherin-catenin complex appears to be increasingly delicate with regard to cancer prognosis. beta-Catenin, one of the components of the adhesion complex, also plays a significant role in cell signal transduction, gene activation, apoptosis inhibition, and increased cellular proliferation and migration.

CONCLUSION

Inactivation of the E-cadherin-catenin adhesion complex, induced by genetic and epigenetic events, plays a significant role in multistage carcinogenesis, and seems to be associated with dedifferentiation, local invasion, regional metastasis, and reduced survival in lung cancer.

Cellular and molecular alterations in spinal cord injury patients with pressure ulcers: a preliminary report

The study was designed to investigate the changes, both numerically and functionally, of the molecules critical to wound healing in spinal cord injury (SCI) patients. Spinal cord injury patients who demonstrated delayed healing of their pressure ulcers were used as study subjects. Age-matched healthy individuals served as controls. Adhesion molecule expression of the peripheral blood leukocytes, including lymphocytes and granulocytes, was measured by flow cytometric analysis. Binding capacity of the lymphocytes was evaluated using human umbilical cord vein endothelial cells (HUVECs) as the binding matrix. Samples from pressure ulcers of the patients were immunostained to define fibronectin, kalinin, beta4 integrin, alpha2beta1, alpha3beta1, alpha5beta1, and CD138 expression. Compared to healthy controls, there was decreased expression of CD11a, CD11b, CD18, CD49b, CD49c, CD49d, CD54, and CD8 in patients' lymphocyte populations and CD11a, CD18, CD49c, CD49d, and CD8 in patients' granulocyte populations. The binding capacity, expressed as percentage binding of the lymphocytes to the HUVEC matrix, was greatly diminished in the patients. There was markedly diminished immunohistochemical staining of fibronectin in pressure ulcers. These findings showed that delayed healing of pressure ulcers in SCI patients can be attributed to reduced adhesion molecule expression, impaired cell-cell interaction, and lack of extracellular matrix structural and functional protein.

Impact of a nickel-reduced stainless steel implant on striated muscle microcirculation: a comparative in vivo study

The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. With moderately good physical and corrosion characteristics, implant-quality stainless steel is particularly popular in orthopedic surgery. However, due to the presence of a considerable amount of nickel in the alloy, concern has been voiced in respect to local tissue responses. More recently a stainless steel alloy with a significant reduction of nickel has become commercially available. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to this nickel-reduced alloy, and compared these results with those of the materials conventional stainless steel and titanium. Using the hamster dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that reduction of the nickel quantity in a stainless steel implant has a positive effect on local microvascular parameters. Although the implantation of a conventional stainless steel sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity, marked leukocyte extravasation, and considerable venular dilation, animals with a nickel-reduced stainless steel implant showed only a moderate increase of these parameters, with a clear tendency of recuperation. Titanium implants merely caused a transient increase of leukocyte-endothelial cell interaction within the first 120 min, and no significant change in macromolecular leakage, leukocyte extravasation, or venular diameter. Pending biomechanical and corrosion testing, nickel-reduced stainless steel may be a viable alternative to conventional implant-quality stainless steel for biomedical applications. Concerning tolerance by the local vascular system, titanium currently remains unsurpassed.

Immunopathology of Bartonella vinsonii (berkhoffii) in experimentally infected dogs

Following natural infection with Bartonella, dogs and humans develop comparable disease manifestations including endocarditis, peliosis hepatis, and granulomatous disease. As the immunologic response to infection in these hosts has not been clearly established, data presented here was derived from the experimental infection of six specific pathogen free (SPF) beagles with a known pathogenic strain of Bartonella. Six dogs were inoculated intravenously with 10(9)cfu of B. vinsonii ssp. berkhoffii and six control dogs were injected intravenously with an equivalent volume of sterile saline. Despite production of substantial levels of specific antibody, blood culture and molecular analyses indicated that Bartonella established chronic infection in these dogs. Flow cytometric analysis of monocytes indicated impaired bacterial phagocytosis during chronic Bartonella infection. There was also a sustained decrease in the percentage of CD8+ lymphocytes in the peripheral blood. Moreover, modulation of adhesion molecule expression (downregulation of L-selectin, VLA-4, and LFA-1) on CD8+ lymphocytes suggested quantitative and qualitative impairment of this cell subset in Bartonella-infected dogs. When compared with control dogs, flow cytometric analysis of lymph node (LN) cells from B. vinsonii infected dogs revealed an expanded population of CD4+ T cells with an apparent naïve phenotype (CD45RA+/CD62L+/CD49D(dim)). However, fewer B cells from infected dogs expressed cell-surface MHC II, implicating impaired antigen presentation to helper T cells within LN. Taken together, results from this study indicate that B. vinsonii establishes chronic infection in dogs which may result in immune suppression characterized by defects in monocytic phagocytosis, an impaired subset of CD8+ T lymphocytes, and impaired antigen presentation within LN.

The role of tumor cell adhesion as an important factor in formation of distant colorectal metastasis

PURPOSE

The interactions of blood-borne colorectal carcinoma cells with vascular endothelium are important during hematogenous formation of distant metastases. To adhere to the vessel wall, circulating carcinoma cells that come into contact with the microvasculature must resist the attractive forces of the flow of plasma and other circulating cells that tend to detach them from the wall.

METHODS

Hydrodynamic adhesion assays have been introduced to mimic the microcirculation and investigate cell adhesion under flow conditions. Different aspects of colorectal cancer cell adhesion during hematogenous formation of distant metastases are summarized and discussed in this review.

RESULTS

Adhesion of colorectal carcinoma cells to endothelial cells and extracellular matrix is influenced by the presence of fluid flow. Shear forces alone are able to induce signal transduction events in these cells that result in cell activation and modification of adhesive behavior.

CONCLUSIONS

Consideration of fluid dynamics of circulating colorectal cancer cell movement in the microcirculation leads to new knowledge of in vivo processes that are involved in tumor cell adhesion to the vessel wall in host organs. Shear forces have been found to influence adhesive properties of colorectal carcinoma cells to endothelial cells and underlying subendothelial extracellular matrix. Understanding the complex processes involved in tumor cell adhesion may result in the development of novel therapeutic strategies.

Reduction of inflammatory response in composite flap transfer by local stress conditioning-induced heat-shock protein 32

BACKGROUND

The failure of composite flaps despite anastomotic patency is thought to be mediated by the inflammatory response within the microvasculature, which results from unavoidable surgical trauma and transfer-related ischemia-reperfusion. Evidence suggests that stress conditioning may improve flap survival; however, the molecular mechanisms of protection are far from being clear. Therefore, we analyzed whether stress conditioning-induced heat-shock protein 32 is effective to prevent the inflammatory response in transferred osteomyocutaneous flaps.

METHODS

In a rat model, leukocyte-endothelial cell interaction and endothelial integrity disruption as early indicators of the inflammatory response were quantitatively analyzed in muscle, subcuticular tissue, and periosteum of microvascularly transferred osteomyocutaneous flaps by using intravital fluorescence microscopy. Twenty-four hours before flap transfer, stress conditioning was induced by local heating of the left hindlimb up to 42.5 degrees C for 30 minutes. In additional animals, stress conditioning-induced activity of heat-shock protein 32 was inhibited by tin protoporphyrin-IX. Unconditioned flaps served as controls.

RESULTS

In all tissues analyzed, control flaps showed significant leukocyte adherence in postcapillary venules, increased intercellular adhesion molecule-1 (ICAM-1) expression, and endothelial integrity disruption, but a lack of heat-shock protein 32. In contrast, stress conditioning induced marked heat-shock protein 32 expression, which was associated with a significant reduction (P <.05) of leukocyte adherence, ICAM-1 expression, and endothelial hyperpermeability. The inhibition of heat-shock protein 32 by tin protoporphyrin-IX completely abolished the stress conditioning-induced amelioration of the inflammatory response in all tissues analyzed.

CONCLUSIONS

Stress conditioning by local heat-shock priming reduces the inflammatory response in osteomyocutaneous flaps. The protective effect is predominantly mediated by the induction of heat-shock protein 32.

Upregulated Expression of Rat Heart Intercellular Adhesion Molecule-1 in Angiotensin II- but Not Phenylephrine- Induced Hypertension

-Intercellular adhesion molecule-1 (ICAM-1), part of an immunoglobulin-like superfamily of adhesion molecules, is involved in several cardiovascular diseases. We investigated whether in vivo angiotensin II (Ang II) increases ICAM-1 in rats. Sprague-Dawley rats were infused with vehicle or Ang II (750 µg. kg(-1). d(-1) SC) for 7 days. The contribution of Ang II receptors to ICAM-1 expression was investigated with a nonpeptide Ang II type 1 (AT(1)) receptor antagonist losartan (30 mg. kg(-1). d(-1) in drinking water). Systolic blood pressure was elevated in Ang II-treated animals compared with sham-treated controls, and losartan blocked this increase. Tumor necrosis factor (TNF)-alpha (5 µg/kg IP bolus), a prototype inducer of ICAM-1, was administered as a positive control for ICAM-1 expression. After treatment, hearts were frozen in liquid nitrogen; homogenates were subjected to SDS-PAGE and immunoblotted with an anti-rat ICAM-1 monoclonal antibody. We detected a predominantly high-molecular-weight band in homogenates from non-TNF-alpha-treated rats, which was enhanced by 80+/-5% in TNF-alpha-treated rats. This band measured approximately 200 kDa, which is the molecular weight of ICAM-1 in its native dimer form. The same band was detected in homogenates from sham and Ang II-treated rats, with the latter showing a 150+/-10% increase in ICAM-1 versus sham controls. Immunoprecipitation of rat heart homogenates with anti-rat ICAM-1 antibody resulted in a dominant band of the same molecular weight as samples not treated with antibody. Losartan prevented enhanced expression of ICAM-1 in the presence of Ang II but had no effect on basal ICAM-1 expression. Phenylephrine, an alpha-agonist (3 mg. kg(-1). d(-1) ), was infused for 1 week but had no effect on ICAM-1 expression, even though systolic blood pressure was elevated to the same level as in rats treated with Ang II. Thus, heart ICAM-1 expression is enhanced via AT(1) receptor activation independent of hypertension. Ang II-induced ICAM-1 expression was time and dose dependent, with maximal expression occurring within 5 to 7 days at 100 to 750 µg/kg Ang II. Immunohistochemical staining demonstrated markedly increased ICAM-1 levels in the perivascular area in Ang II-infused rats. Monocyte/macrophage accumulation was significantly greater in Ang II-treated rat hearts than in sham-treated hearts (10+/-1; P:<0.001; n=5). Thus during inflammation, overexpression of ICAM-1 may contribute to cardiovascular damage in diseases characterized by increased activity of the renin-angiotensin system.

Response of inflammatory markers to balloon angioplasty in peripheral arterial occlusive disease

OBJECTIVES

To study the inflammatory response to balloon angioplasty (PTA).

DESIGN

Prospective study.

MATERIALS

Blood samples were drawn for cytokine analysis from 10 patients undergoing PTA before, after 60 min and 6 h after the balloon inflation. Adhesion molecules were analysed in 14 patients undergoing PTA and in seven patients undergoing angiography only. Arterial samples were taken in eight patients, before PTA, immediately after and 15 min later. Venous samples were taken in six patients and in the group undergoing angiography only. The sampling was before, 60, 90 and 120 min after the procedure. As controls served 15 patients with no signs of peripheral arterial disease.

METHODS

Cytokines (IL-6, TNF-alpha) were analysed using ELISA. Adhesion molecule expression on WBC was measured by flow cytometry.

RESULTS

A significant increase of IL-6 in the sample taken 6 h after the last balloon inflation was seen in five patients. TNF-alpha was raised only in one patient. The group of patients with peripheral arterial occlusive disease (PAOD) expressed pre-interventionally a higher level of adhesion molecules on WBC compared to the controls. The expression of adhesion molecules (CD11b/CD18) was significantly decreased after PTA.

CONCLUSION

Only a very limited cytokine response is caused by PTA reflecting the small surgical trauma. PTA results in a downregulation of detectable CD11b/CD18 expression on WBC in the circulation, which may reflect removal of activated cells through adhesion and extravasation.