Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008.

OBJECTIVE: To provide an update to the original Surviving Sepsis Campaign clinical management guidelines, "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," published in 2004. DESIGN: Modified Delphi method with a consensus conference of 55 international experts, several subsequent meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee. This process was conducted independently of any industry funding. METHODS: We used the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations. A strong recommendation (1) indicates that an intervention's desirable effects clearly outweigh its undesirable effects (risk, burden, cost) or clearly do not. Weak recommendations (2) indicate that the tradeoff between desirable and undesirable effects is less clear. The grade of strong or weak is considered of greater clinical importance than a difference in letter level of quality of evidence. In areas without complete agreement, a formal process of resolution was developed and applied. Recommendations are grouped into those directly targeting severe sepsis, recommendations targeting general care of the critically ill patient that are considered high priority in severe sepsis, and pediatric considerations. RESULTS: Key recommendations, listed by category, include early goal-directed resuscitation of the septic patient during the first 6 hrs after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm potential source of infection (1C); administration of broad-spectrum antibiotic therapy within 1 hr of diagnosis of septic shock (1B) and severe sepsis without septic shock (1D); reassessment of antibiotic therapy with microbiology and clinical data to narrow coverage, when appropriate (1C); a usual 7-10 days of antibiotic therapy guided by clinical response (1D); source control with attention to the balance of risks and benefits of the chosen method (1C); administration of either crystalloid or colloid fluid resuscitation (1B); fluid challenge to restore mean circulating filling pressure (1C); reduction in rate of fluid administration with rising filing pressures and no improvement in tissue perfusion (1D); vasopressor preference for norepinephrine or dopamine to maintain an initial target of mean arterial pressure > or = 65 mm Hg (1C); dobutamine inotropic therapy when cardiac output remains low despite fluid resuscitation and combined inotropic/vasopressor therapy (1C); stress-dose steroid therapy given only in septic shock after blood pressure is identified to be poorly responsive to fluid and vasopressor therapy (2C); recombinant activated protein C in patients with severe sepsis and clinical assessment of high risk for death (2B except 2C for postoperative patients). In the absence of tissue hypoperfusion, coronary artery disease, or acute hemorrhage, target a hemoglobin of 7-9 g/dL (1B); a low tidal volume (1B) and limitation of inspiratory plateau pressure strategy (1C) for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure in acute lung injury (1C); head of bed elevation in mechanically ventilated patients unless contraindicated (1B); avoiding routine use of pulmonary artery catheters in ALI/ARDS (1A); to decrease days of mechanical ventilation and ICU length of stay, a conservative fluid strategy for patients with established ALI/ARDS who are not in shock (1C); protocols for weaning and sedation/analgesia (1B); using either intermittent bolus sedation or continuous infusion sedation with daily interruptions or lightening (1B); avoidance of neuromuscular blockers, if at all possible (1B); institution of glycemic control (1B), targeting a blood glucose < 150 mg/dL after initial stabilization (2C); equivalency of continuous veno-veno hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1A); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding using H2 blockers (1A) or proton pump inhibitors (1B); and consideration of limitation of support where appropriate (1D). Recommendations specific to pediatric severe sepsis include greater use of physical examination therapeutic end points (2C); dopamine as the first drug of choice for hypotension (2C); steroids only in children with suspected or proven adrenal insufficiency (2C); and a recommendation against the use of recombinant activated protein C in children (1B). CONCLUSIONS: There was strong agreement among a large cohort of international experts regarding many level 1 recommendations for the best current care of patients with severe sepsis. Evidenced-based recommendations regarding the acute management of sepsis and septic shock are the first step toward improved outcomes for this important group of critically ill patients.

Acute endotoxemia inhibits microvascular nitric oxide-dependent vasodilation in humans.

Nitric oxide (NO) is crucial for the microvascular homeostasis, but its role played in the microvascular alterations during sepsis remains controversial. We investigated NO-dependent vasodilation in the skin microcirculation and plasma levels of asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of the NO synthases, in a human model of sepsis. In this double-blind, randomized, crossover study, microvascular NO-dependent (local thermal hyperemia) and NO-independent vasodilation (post-occlusive reactive hyperemia) assessed by laser Doppler imaging, plasma levels of ADMA, and l-arginine were measured in seven healthy obese volunteers, immediately before and 4 h after either a i.v. bolus injection of Escherichia coli endotoxin (LPS; 2 ng/kg) or normal saline (placebo) on two different visits at least 2 weeks apart. LPS caused the expected systemic effects, including increases in heart rate (+43%, P < 0.001), cardiac output (+16%, P < 0.01), and rectal temperature (+1.4°C, P < 0.001), without change in arterial blood pressure. LPS affected neither baseline skin blood flow nor post-occlusive reactive hyperemia but decreased the NO-dependent local thermal hyperemia response, l-arginine, and, to a lesser extent, ADMA plasma levels. The changes in NO-dependent vasodilation were not correlated with the corresponding changes in the plasma levels of ADMA, l-arginine, or the l-arginine/ADMA ratio. Our results show for the first time that experimental endotoxemia in humans causes a specific decrease in endothelial NO-dependent vasodilation in the microcirculation, which cannot be explained by a change in ADMA levels. Microvascular NO deficiency might be responsible for the heterogeneity of tissue perfusion observed in sepsis and could be a therapeutic target.

Intraoperative cerebral perfusion and postoperative cognitive dysfunction in geriatric patients

Background: Inadequate intraoperative cerebral perfusion has been suggested as a possible cause of postoperative cognitive dysfunction (POCD). Methods: We investigated 35 patients aged 65 or older undergoing elective major non-cardiac surgery under standardized general anaesthesia (thiopental, sevoflurane, fentanyl, atracurium). Intraoperative cerebral perfusion was monitored with transcranial Doppler, and near-infrared spectroscopy (NIRS). Arterial blood pressure was monitored continuously with a Finapres device. Mx, an index allowing continuous monitoring of cerebrovascular autoregulation based on the changes in mean arterial blood pressure (MAP) and cerebral blood flow velocity was calculated. Mx >0.5 was defined as disturbed cerebrovascular autoregulation. Cognitive function was measured preoperatively and 7 days postoperatively using the CERAD-NAB Plus test battery. A postoperative decline >1 z-score in at least two of the tested domains was defined as POCD. Data are shown as mean } SD. Results: Mean age was 75 } 7 yrs. Sixteen patients (46%) developed POCD. These patients were older (77 } 8 vs 73 } 7 yrs), had lower MAP (77 } 12 vs 81 } 11 mm Hg), lower cerebral tissue oxygenation indices measured by NIRS (66.8 } 6.0 vs 68.6 } 4.3%) and less efficient cerebrovascular autoregulation (Mx 0.54 } 0.17 and 0.44 } 0.22) than patients without POCD. Disturbed intraoperative cerebrovascular autoregulation was found more often (56 vs 37%) in patients with POCD. However, none of these differences reached statistical significance. Conclusions: Our data show a trend towards subtle changes in intraoperative cerebral perfusion in elderly patients who develop POCD. However, a cause effect relationship must not be assumed and a greater number of patients needs to be investigated patients. However, more patients need to be investigated to confirm and characterize these differences.

PET Molecular Imaging of Hypoxia in Ischemic Stroke: An Update.

Hypoxia, a condition of insufficient oxygen availability to support metabolism, occurs when the vascular supply is interrupted, as in stroke. The identification of the hypoxic and viable tissue in stroke as compared with irreversible lesions (necrosis) has relevant implications for the treatment of ischemic stroke. Traditionally, imaging by positron emission tomography (PET), using 15O-based radiotracers, allowed the measurement of perfusion and oxygen extraction in stroke, providing important insights in its pathophysiology. However, these multitracer evaluations are of limited applicability in clinical settings. More recently, specific tracers have been developed, which accumulate with an inverse relationship to oxygen concentration and thus allow visualizing the hypoxic tissue non invasively. These belong to two main groups: nitroimidazoles, and among these the 18F-Fluoroimidazole (18F-FMISO) is the most widely used, and the copper-based tracers, represented mainly by Cu-ATSM. While these tracers have been at first developed and tested in order to image hypoxia in tumors, they have also shown promising results in stroke models and preliminary clinical studies in patients with cardiovascular disorders, allowing the detection of hypoxic tissue and the prediction of the extent of subsequent ischemia and clinical outcome. These tracers have therefore the potential to select an appropriate subgroup of patients who could benefit from a hypoxia-directed treatment and provide prognosis relevant imaging. The molecular imaging of hypoxia made important progress over the last decade and has a potential for integration into the diagnostic and therapeutic workup of patients with ischemic stroke.

Transport of methotrexate by the in vitro isolated rabbit proximal tubule.

The tubular transport of [3H]methotrexate was studied in isolated nonperfused and perfused superficial proximal tubular segments of rabbit kidneys. Reabsorption represented only 5% of perfused methotrexate, and appeared to be mostly of passive nature inasmuch as it was not modified by reducing the temperature or by ouabain. Cellular accumulation in nonperfused segments and secretion in perfused tubules were highest in the S2 segment and lower in the S3 and S1 segments. Secretion against a bath-to-lumen concentration gradient was observed only in S2 segments (with a maximum methotrexate secretory rate of 478 +/- 48 fmol/mm.min and an apparent Km of transport of 363 +/- 32 microM), and was inhibited by probenecid and folate. The low capacity for methotrexate secretion may be explained by a low capacity of transport across the basolateral membrane of the proximal cell as methotrexate was accumulated only to a low extent in nonperfused tubules (tissue water to medium concentration ratio of 8.2 +/- 1 in S2 segments). During secretion a small amount of methotrexate was metabolized; the nature of the metabolite(s) remains to be defined.

Photodynamic therapy : a pathway for enhanced delivery of liposomal doxorubicin to tumors

Abstract Part I : Background : Isolated lung perfusion (ILP) was designed for the treatment of loco-regional malignancies of the lung. In contrast to intravenous (IV) drug application, ILP allows for a selective administration of cytostatic agents such as doxorubicin to the lung while sparing non-affected tissues. However, the clinical results with ILP were disappointing. Doxorubicinbased ILP on sarcoma rodent lungs suggested high overall doxorubicin concentrations within the perfused lung but a poor penetration of the cytostatic agent into tumors. The same holds true for liposomal-encapsulated macromolecular doxorubicin (LiporubicinTM) In specific conditions, low-dose photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial bamer in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vasculature. We therefore hypothesized that Visudyne®-mediated PDT could selectively increase liposomal doxorubicin (LiporubicinTM) uptake in sarcoma tumors to rodent lungs during intravenous (IV) drug administration and isolated lung perfusion (ILP). Material and Methods : A sarcoma tumor was generated in the left lung of Fisher rats by subpleural injection of a sarcoma cell ,suspension via thoracotomy. Ten days later, LiporubicinTM is administered IV or by single pass antegrade ILP, with or without Visudyne® -mediated low-dose PDT pre-treatment of the sarcoma bearing lung. The drug concentration and distribution were assessed separately in tumors and lung tissues by high pressure liquid chromatography (HPLC) and fluorescence microscopy (FNI~, respectively. Results : PDT pretreatment before IV LiporubicinTM administration resulted in a significantly higher tumor drug uptake and tumor to lung drug ratio compared to IV drug injection alone without affecting the blood flow and drug distribution in the lung. PDT pre-treatment before LiporubicinTM-based ILP also resulted in a higher tumor drug uptake and a higher tumor to lung drug ratio compared to ILP alone, however, these differences were not significant due to a heterogeneous blood flow drug distribution during ILP which was further accentuated by PDT. Conclusions : Low-dose Visudyne®-mediated PDT pre-treatment has the potential to selectively enhance liposomal encapsulated doxorubicin uptake in tumors but not in normal lung tissue after IV drug application in a rat model of sarcoma tumors to the lung which opens new perspectives for the treatment of superficially spreading chemoresistant tumors of the chest cavity such as mesothelioma or malignant effusion. However, the impact of PDT on macromolecular drug uptake during ILP is limited since its therapeutic advantage is circumvented by ILP-induced heterogeneicity of blood flow and drug distribution Abstract Part II Background : Photodynamic therapy (PDT) with Visudyne® acts by direct cellular phototoxicity and/or by an indirect vascular-mediated effect. Here, we demonstrate that the vessel integrity interruption by PDT can promote the extravasation of a macromolecular agent in normal tissue. To obtain extravasation in normal tissue PDT conditions were one order of magnitude more intensive than the ones in tissue containing neovessels reported in the literature. Material and Methods : Fluorescein isothiocyanate dextran (FITC-D, 2000kDa), a macromolecular agent, was intravenously injected 10 minutes before (LKO group, n=14) or 2 hours (LK2 group, n=16) after Visudyne® mediated PDT in nude mice bearing a dorsal skin fold chamber. Control animals had no PDT (CTRL group, n=8). The extravasation of FITC-D from blood vessels in striated muscle tissue was observed in both groups in real-time for up to 2500 seconds after injection. We also monitored PDT-induced leukocyte rolling in-vivo and assessed, by histology, the corresponding inflammatory reaction score in the dorsal skin fold chambers. Results : In all animals, at the applied PDT conditions, FITC-D extravasation was significantly enhanced in the PDT treated areas as compared to the surrounding non-treated areas (p<0.0001). There was no FITC-D leakage in the control animals. Animals from the LKO group had significantly less FITC-D extravasation than those from the LK2 group (p = 0.0002). In the LKO group FITC-D leakage correlated significantly with the inflammation (p < 0.001). Conclusions: At the selected conditions, Visudyne-mediated PDT promotes vascular leakage and FITC-D extravasation into the interstitial space of normal tissue. The intensity of vascular leakage depends on the time interval between PDT and FITC-D injection. This concept could be used to locally modulate the delivery of macromolecules in vivo. Résumé : La perfusion cytostatique isolée du poumon permet une administration sélective des agents cytostatiques sans implication de la circulation systémique avec une forte accumulation au niveau du poumon mais une faible pénétration dans les tumeurs. La thérapie photodynamique (PDT) qui consiste en l'application d'un sensibilisateur activé par lumière laser non- thermique d'une longueur d'onde définie permet dans certaines conditions, une augmentation de la pénétration des agents cytostatiques macromoléculaires à travers la barrière endothéliale tumorale. Nous avons exploré cet avantage thérapeutique de la PDT dans un modèle expérimental afin d'augmenter d'une manière sélective la pénétration tumorale de la doxorubicin pegylée, liposomal- encapsulée macromoléculaire (Liporubicin). Une tumeur sarcomateuse a été générée au niveau du poumon de rongeur suivie d'administration de Liporubicin, soit par voie intraveineuse soit par perfusion isolée du poumon (ILP). Une partie des animaux ont reçus un prétraitement de la tumeur et du poumon sous jacent par PDT avec Visudyne comme photosensibilisateur. Les résultats ont démontrés que la PDT permet, sous certaines conditions, une augmentation sélective de Liporubicin dans les tumeurs mais pas dans le parenchyme pulmonaire sous jacent. Après administration intraveineuse de Liporubicin et prétraitement par PDT, l'accumulation dans les tumeurs était significative par rapport au poumon, et aux tumeurs sans PDT. Le même phénomène est observé après ILP du poumon. Cependant, les différences avec ou sans PDT n'étaient pas significatives lié à und distribution hétérogène de Liporubicin dans le poumon perfusé après ILP. Dans une deuxième partie de l'expérimentation, nous avons exploré la microscopie intra-vitale pour déterminer l'extravasion des substances macromoléculaires (FITS) à travers la barrière endothéliale avec ou sans Visudyne-PDT au niveau des chambres dorsales des souris nues. Les résultats montrent qu'après PDT, l'extravasion de FITS a été augmentée de manière significative par rapport au tissu non traité. L'intensité de l'extravasion de FITS dépendait également de l'intervalle entre PDT et injection de FITS. En conclusion, les expérimentations montrent que la PDT est capable, sous certaines conditions, d'augmenter de manière significative l'extravasion des macromolécules à travers la barrière endothéliale et leur accumulation dans des tumeurs mais pas dans le parenchyme pulmonaire. Ces résultats permettent une nouvelle perspective de traitement pour des tumeurs superficielles intrathoraciques chimio-résistent comme l'épanchement pleural malin ou le mésothéliome pleural.

Soft tissue sarcomas with complex genomic profiles.

Soft tissue sarcomas (STS) with complex genomic profiles (50% of all STS) are predominantly composed of spindle cell/pleomorphic sarcomas, including leiomyosarcoma, myxofibrosarcoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma, malignant peripheral nerve sheath tumor, angiosarcoma, extraskeletal osteosarcoma, and spindle cell/pleomorphic unclassified sarcoma (previously called spindle cell/pleomorphic malignant fibrous histiocytoma). These neoplasms show, characteristically, gains and losses of numerous chromosomes or chromosome regions, as well as amplifications. Many of them share recurrent aberrations (e.g., gain of 5p13-p15) that seem to play a significant role in tumor progression and/or metastatic dissemination. In this paper, we review the cytogenetic, molecular genetic, and clinicopathologic characteristics of the most common STS displaying complex genomic profiles. Features of diagnostic or prognostic relevance will be discussed when needed.

Establishing an association between a peri-operative perfusion score system (PerfSCORE) and post-operative patient morbidity/mortality during CPB cardiac surgery.

BACKGROUND: To date, there is no quality assurance program that correlates patient outcome to perfusion service provided during cardiopulmonary bypass (CPB). A score was devised, incorporating objective parameters that would reflect the likelihood to influence patient outcome. The purpose was to create a new method for evaluating the quality of care the perfusionist provides during CPB procedures and to deduce whether it predicts patient morbidity and mortality. METHODS: We analysed 295 consecutive elective patients. We chose 10 parameters: fluid balance, blood transfused, Hct, ACT, PaO2, PaCO2, pH, BE, potassium and CPB time. Distribution analysis was performed using the Shapiro-Wilcoxon test. This made up the PerfSCORE and we tried to find a correlation to mortality rate, patient stay in the ICU and length of mechanical ventilation. Univariate analysis (UA) using linear regression was established for each parameter. Statistical significance was established when p < 0.05. Multivariate analysis (MA) was performed with the same parameters. RESULTS: The mean age was 63.8 +/- 12.6 years with 70% males. There were 180 CABG, 88 valves, and 27 combined CABG/valve procedures. The PerfSCORE of 6.6 +/- 2.4 (0-20), mortality of 2.7% (8/295), CPB time 100 +/- 41 min (19-313), ICU stay 52 +/- 62 hrs (7-564) and mechanical ventilation of 10.5 +/- 14.8 hrs (0-564) was calculated. CPB time, fluid balance, PaO2, PerfSCORE and blood transfused were significantly correlated to mortality (UA, p < 0.05). Also, CPB time, blood transfused and PaO2 were parameters predicting mortality (MA, p < 0.01). Only pH was significantly correlated for predicting ICU stay (UA). Ultrafiltration (UF) and CPB time were significantly correlated (UA, p < 0.01) while UF (p < 0.05) was the only parameter predicting mechanical ventilation duration (MA). CONCLUSIONS: CPB time, blood transfused and PaO2 are independent risk factors of mortality. Fluid balance, blood transfusion, PaO2, PerfSCORE and CPB time are independent parameters for predicting morbidity. PerfSCORE is a quality of perfusion measure that objectively quantifies perfusion performance.

Translation of biomechanical concepts in bone tissue engineering: from animal study to revision knee arthroplasty.

Bone defects in revision knee arthroplasty are often located in load-bearing regions. The goal of this study was to determine whether a physiologic load could be used as an in situ osteogenic signal to the scaffolds filling the bone defects. In order to answer this question, we proposed a novel translation procedure having four steps: (1) determining the mechanical stimulus using finite element method, (2) designing an animal study to measure bone formation spatially and temporally using micro-CT imaging in the scaffold subjected to the estimated mechanical stimulus, (3) identifying bone formation parameters for the loaded and non-loaded cases appearing in a recently developed mathematical model for bone formation in the scaffold and (4) estimating the stiffness and the bone formation in the bone-scaffold construct. With this procedure, we estimated that after 3 years mechanical stimulation increases the bone volume fraction and the stiffness of scaffold by 1.5- and 2.7-fold, respectively, compared to a non-loaded situation.

Cerebral perfusion CT: Current state of the art : P44

Purpose: The aim of this educational poster is to introduce the technical principles of cerebral perfusion CT and to provide examples of its clinical applications and potential limitations in the everyday emergency practice. Methods and materials: Cerebral perfusion CT is a well established investigatory tool for many vascular and parenchymal brain dysfunctions. CT perfusion maps allow a semiquantitative assessment of cerebral perfusion. Results: Currently, cerebral perfusion CT has a pivotal role in differentiating reversible from irreversible ischemic parenchymal insult besides its integral role in grading vasospasm after subarachnoid hemorrhage. Furthermore, cerebral perfusion CT can be coupled to acetazolamide administration in order to assess the cerebrovascular reserve capacity before performing extra-/intra-cranial bypass surgery in patients with cerebral vascular insufficiency. Cerebral perfusion CT can also identify diffuse abnormalities of cerebral perfusion in children with traumatic brain injury showing a low initial GCS in order to predict the final outcome regarding the late occurrence of irreversible parenchymal damage. Cerebral Perfusion CT is also able to detect focal parenchymal perfusion abnormalities in acute epileptic seizures. Conclusion: Cerebral perfusion CT can be integrated in the management of many vascular, traumatic and functional disorders of the brain.

Effect of carbohydrate overfeeding on whole body macronutrient metabolism and expression of lipogenic enzymes in adipose tissue of lean and overweight humans

OBJECTIVE: Lipids stored in adipose tissue can originate from dietary lipids or from de novo lipogenesis (DNL) from carbohydrates. Whether DNL is abnormal in adipose tissue of overweight individuals remains unknown. The present study was undertaken to assess the effect of carbohydrate overfeeding on glucose-induced whole body DNL and adipose tissue lipogenic gene expression in lean and overweight humans. DESIGN: Prospective, cross-over study. SUBJECTS AND METHODS: A total of 11 lean (five male, six female, mean BMI 21.0+/-0.5 kg/m(2)) and eight overweight (four males, four females, mean BMI 30.1+/-0.6 kg/m(2)) volunteers were studied on two occasions. On one occasion, they received an isoenergetic diet containing 50% carbohydrate for 4 days prior to testing; on the other, they received a hyperenergetic diet (175% energy requirements) containing 71% carbohydrates. After each period of 4 days of controlled diet, they were studied over 6 h after having received 3.25 g glucose/kg fat free mass. Whole body glucose oxidation and net DNL were monitored by means of indirect calorimetry. An adipose tissue biopsy was obtained at the end of this 6-h period and the levels of SREBP-1c, acetyl CoA carboxylase, and fatty acid synthase mRNA were measured by real-time PCR. RESULTS: After isocaloric feeding, whole body net DNL amounted to 35+/-9 mg/kg fat free mass/5 h in lean subjects and to 49+/-3 mg/kg fat free mass/5 h in overweight subjects over the 5 h following glucose ingestion. These figures increased (P<0.001) to 156+/-21 mg/kg fat free mass/5 h in lean and 64+/-11 mg/kg fat free mass/5 h (P<0.05 vs lean) in overweight subjects after carbohydrate overfeeding. Whole body DNL after overfeeding was lower (P<0.001) and glycogen synthesis was higher (P<0.001) in overweight than in normal subjects. Adipose tissue SREBP-1c mRNA increased by 25% in overweight and by 43% in lean subjects (P<0.05) after carbohydrate overfeeding, whereas fatty acid synthase mRNA increased by 66 and 84% (P<0.05). CONCLUSION: Whole body net DNL is not increased during carbohydrate overfeeding in overweight individuals. Stimulation of adipose lipogenic enzymes is also not higher in overweight subjects. Carbohydrate overfeeding does not stimulate whole body net DNL nor expression of lipogenic enzymes in adipose tissue to a larger extent in overweight than lean subjects.

Simultaneous cell morphometry and refractive index measurement with dual-wavelength digital holographic microscopy and dye-enhanced dispersion of perfusion medium.

Digital holographic microscopy (DHM) allows optical-path-difference (OPD) measurements with nanometric accuracy. OPD induced by transparent cells depends on both the refractive index (RI) of cells and their morphology. This Letter presents a dual-wavelength DHM that allows us to separately measure both the RI and the cellular thickness by exploiting an enhanced dispersion of the perfusion medium achieved by the utilization of an extracellular dye. The two wavelengths are chosen in the vicinity of the absorption peak of the dye, where the absorption is accompanied by a significant variation of the RI as a function of the wavelength.

Mitochondrial reactive oxygen species generation triggers inflammatory response and tissue injury associated with hepatic ischemia-reperfusion: Therapeutic potential of mitochondrially targeted antioxidants.

Mitochondrial reactive oxygen species generation has been implicated in the pathophysiology of ischemia-reperfusion (I/R) injury; however, its exact role and its spatial-temporal relationship with inflammation are elusive. Herein we explore the spatial-temporal relationship of oxidative/nitrative stress and inflammatory response during the course of hepatic I/R and the possible therapeutic potential of mitochondrial-targeted antioxidants, using a mouse model of segmental hepatic ischemia-reperfusion injury. Hepatic I/R was characterized by early (at 2h of reperfusion) mitochondrial injury, decreased complex I activity, increased oxidant generation in the liver or liver mitochondria, and profound hepatocellular injury/dysfunction with acute proinflammatory response (TNF-α, MIP-1α/CCL3, MIP-2/CXCL2) without inflammatory cell infiltration, followed by marked neutrophil infiltration and a more pronounced secondary wave of oxidative/nitrative stress in the liver (starting from 6h of reperfusion and peaking at 24h). Mitochondrially targeted antioxidants, MitoQ or Mito-CP, dose-dependently attenuated I/R-induced liver dysfunction, the early and delayed oxidative and nitrative stress response (HNE/carbonyl adducts, malondialdehyde, 8-OHdG, and 3-nitrotyrosine formation), and mitochondrial and histopathological injury/dysfunction, as well as delayed inflammatory cell infiltration and cell death. Mitochondrially generated oxidants play a central role in triggering the deleterious cascade of events associated with hepatic I/R, which may be targeted by novel antioxidants for therapeutic advantage.

Bone tissue engineering using foetal cell therapy.

Different cell sources for bone tissue engineering are reviewed. In particular, adult cell source strategies have been based on the implantation of unfractionated fresh bone marrow; purified, culture expanded mesenchymal stem cells, differentiated osteoblasts, or cells that have been modified genetically to express rhBMP. Several limiting factors are mentioned for these strategies such as low number of available cells or possible immunological reaction of the host. Foetal bone cells are presented as an alternative solution and review of actual treatments using these cells is presented. Finally, foetal cells used specifically for bone tissue engineering are characterised and potentially interesting therapeutic options are proposed.

Total aortic arch stenting--hemodynamical impact of carotid artery perfusion.

The aim of this experimental study is to evaluate the feasibility and the outcome of total endovascular stent implantation in the aortic arch. Indications for this operation-technique would be acute or chronic dissection of the aortic arch (non-A-non-B dissection) or type B dissection with retrograde extension. Four pigs were canulated via the distal abdominal aorta and a retrograde placement of a Djumbodis arch stent (4-9 cm) was controlled by using intravascular ultrasound and intracardiac ultrasound by the inferior cava vein and under radioscopic control. Cerebral perfusion, by using a flow meter placed on one prepared carotid artery, were controlled before, immediate post-procedural (<1 min), and in the early follow-up after aortic arch stent implantation. During the implantation process, especially during balloon inflation and deflation, mean carotid perfusion decreases slightly. A reactive increase of carotid perfusion after stent placements indicates transitory cerebral hypo-perfusion. Non-covered aortic arch stent implantation is technically feasible and could be a potential treatment option in otherwise inoperable arch dissections. The time required for balloon inflation and deflation causes an important risk of cerebral ischemia. The latter can be reduced by transaxillary perfusion.