Resuscitation fluids as drugs: targeting the endothelial glycocalyx / 中华医学杂志(英文版)

Fluid resuscitation is an essential intervention in critically ill patients, and its ultimate goal is to restore tissue perfusion. Critical illnesses are often accompanied by glycocalyx degradation caused by inflammatory reactions, hypoperfusion, shock, and so forth, leading to disturbed microcirculatory perfusion and organ dysfunction. Therefore, maintaining or even restoring the glycocalyx integrity may be of high priority in the therapeutic strategy. Like drugs, however, different resuscitation fluids may have beneficial or harmful effects on the integrity of the glycocalyx. The purpose of this article is to review the effects of different resuscitation fluids on the glycocalyx. Many animal studies have shown that normal saline might be associated with glycocalyx degradation, but clinical studies have not confirmed this finding. Hydroxyethyl starch (HES), rather than other synthetic colloids, may restore the glycocalyx. However, the use of HES also leads to serious adverse events such as acute kidney injury and bleeding tendencies. Some studies have suggested that albumin may restore the glycocalyx, whereas others have suggested that balanced crystalloids might aggravate glycocalyx degradation. Notably, most studies did not correct the effects of the infusion rate or fluid volume; therefore, the results of using balanced crystalloids remain unclear. Moreover, mainly animal studies have suggested that plasma may protect and restore glycocalyx integrity, and this still requires confirmation by high-quality clinical studies.

A hiperemia reativa correlaciona-se com presença de sepse e degradação de glicocálix na unidade de terapia intensiva: um estudo de coorte prospectiva / Reactive hyperemia correlates with the presence of sepsis and glycocalyx degradation in the intensive care unit: a prospective cohort study

RESUMO Objetivo: Investigar se a hiperemia reativa correlaciona-se com marcadores de disfunção endotelial e pode ser utilizada para identificar sepse na doença crítica. Métodos: Trata-se de estudo prospectivo em uma coorte de pacientes críticos. A disfunção endotelial foi avaliada quando da admissão, por meio da quantificação de hiperemia por tonometria arterial periférica e níveis plasmáticos de endotelina 1, E-selectina solúvel, endocana e sindecano 1. Os pacientes sépticos foram comparados com pacientes sem evidência de infecção. Resultados: Cinquenta e oito pacientes sépticos foram comparados com 28 controle. O logaritmo natural da tonometria arterial periférica teve correlação negativa com comorbidades cardiovasculares, severidade da doença e níveis plasmáticos de E-selectina solúvel (p = 0,024) e sindecano 1 (p < 0,001). O logaritmo natural da tonometria arterial periférica foi mais baixo nos pacientes sépticos quando comparado com os de pacientes controle (0,53 ± 0,48 versus 0,69 ± 0,42, respectivamente) e, quando ajustado à idade, o modelo multivariado predisse que cada 0,1 de diminuição em unidades de logaritmo natural da tonometria arterial periférica levou a aumento de 14,6% na probabilidade de infecção. Conclusão: A hiperemia reativa avaliada por tonometria arterial periférica tem estreita relação com E-selectina solúvel e sindecano 1, o que sugere associação entre ativação endotelial, degradação de glicocálix e reatividade vascular. A hiperemia reativa por tonometria arterial periférica parece estar comprometida em pacientes críticos, especialmente os com sepse.

Abstract Objective: To investigate whether reactive hyperemia measured by peripheral arterial tonometry correlates with markers of endothelial dysfunction and may be used to identify sepsis in critical illness. Methods: A prospective study was performed using a cohort of critically ill patients. Endothelial dysfunction was assessed on admission by quantifying reactive hyperemia-peripheral arterial tonometry and plasma levels of endothelin-1, soluble E-selectin, endocan and syndecan-1. Septic patients were compared to patients without evidence of infection. Results: Fifty-eight septic patients were compared to 28 controls. The natural logarithm of reactive hyperemia-peripheral arterial tonometry was negatively correlated with cardiovascular comorbidities, disease severity and plasma levels of soluble E-selectin (p = 0.024) and syndecan-1 (p < 0.001). The natural logarithm of reactive hyperemia-peripheral arterial tonometry was lower in septic patients than in controls (0.53 ± 0.48 versus 0.69 ± 0.42, respectively). When adjusted for age, the multivariable model predicted that each 0.1-unit decrease in natural logarithm of reactive hyperemia-peripheral arterial tonometry increased the odds for infection by 14.6%. m. Conclusion: Reactive hyperemia-peripheral arterial tonometry is closely related to soluble E-selectin and syndecan-1, suggesting an association between endothelial activation, glycocalyx degradation and vascular reactivity. Reactive hyperemia-peripheral arterial tonometry appears to be compromised in critically ill patients, especially those with sepsis.

Glicocálix endotelial: relevancia clínica y enfoque traslacional / Endothelial glycocalyx: clinical relevance and translational approach

El glicocálix endotelial es una estructura sin forma definida que recubre la capa luminal del endotelio vascular y que está constituido, principalmente, por tres elementos: proteoglicanos, glucosaminoglicanos y glicoproteínas. Cumple distintas funciones, como regular la permeabilidad vascular a las moléculas y líquidos, la transducción de las fuerzas mecánicas de tensión y las cascadas de fibrinólisis y coagulación vascular; además, protege de la adhesión leucocitaria, plaquetaria y de patógenos. Los determinantes de lesión del glicocálix pueden ser de varios tipos, por ejemplo, incremento las fuerzas de tensión, especies reactivas de oxígeno (O2), aumento, a nivel plasmático, de sustancias como el sodio (hipernatremia), glucosa (hiperglicemia) y colesterol (hipercolesterolemia), y las moléculas proinflamatorias. Cualquiera de las noxas citadas, individualmente o combinadas, lesionan el glicocálix y la disfunción resultante se expresará clínicamente como disfunción endotelial, aumento de la permeabilidad vascular, paso de lipoproteínas al subendotelio, activación de la coagulación o aumento de la adhesión de plaquetas y leucocitos al endotelio.

Endothelial glycocalyx is an undefined structure covering the luminal layer of the vascular endothelium and consisting mainly of three elements: proteoglycans, glycosaminoglycans and glycoproteins. It has different functions, such as the regulation of vascular permeability to liquids and molecules; transduction of the mechanical forces of vascular tension; regulation of coagulation and fibrinolysis cascades; and protection of leukocyte, platelet and pathogen adhesion. The determinants of a glycocalyx lesion can be of several types­e.g., increased tensile forces; reactive oxygen (O2) species; increased plasma level of substances such as sodium (hypernatremia), glucose (hyperglycemia) and cholesterol (hypercholesterolemia); and pro-inflammatory molecules. Any of the above-mentioned noxas, alone or combined, injure the glycocalyx. Its dysfunction will be clinically expressed as endothelial dysfunction, increased vascular permeability, filtration of lipoproteins to the subendothelium, activation of coagulation, or increased adhesion of leukocytes and platelets to the endothelium.

Revisión Bibliográfica: Glicocálix Endotelial como Blanco de Agresión del Fenómeno Isquemia Reperfusión / Bibliographic Review: Endothelial Glycocalyx as Target of Aggression of the Ischemia-Reperfusion Injury

El glicocálix endotelial es una estructura rica en glucosaminoglicanos, proteoglicanos y glucoproteínas que recubre el endotelio vascular; además de ser una estructura de protección, al estar en contacto directo con la sangre se convierte en el blanco de agresión de diversos mecanismos fisiopatológicos. El fenómeno isquemia-reperfusión se presenta comúnmente en varias entidades del paciente crítico, incluyendo: eventos cerebro vasculares isquémicos, síndrome coronario agudo, sepsis y choque en sus distintos tipos, traumatismos mayores, cirugía y trasplante. Las complicaciones derivadas de este fenómeno son múltiples y dependientes del sitio de presentación; el común denominador es la disfunción microvascular que potencialmente podría desencadenar un fallo multisistémico. El objetivo de esta revisión bibliográfica fue realizar una actualización de los conocimientos en relación a la injuria del glicocálix endotelial durante el fenómeno isquemia-reperfusión.(au)

The endothelial glycocalyx is a structure rich in glycosaminoglycans, proteoglycans and glycoproteins that cover vascular endothelium; in addition of being a protective structure, the direct contact with blood turns it the target of aggression of multiple physiopathological mechanisms. The ischemia-reperfusion injury commonly presents in several critical care entities, including: ischemic stroke, acute coronary syndrome, sepsis and shock, major trauma, surgery and transplantation. Complications are multiple and dependent of the site of presentation; the common denominator is microvascular dysfunction that could potentially trigger multiple organ dysfunction syndrome. The aim of this bibliographic review was to update the knowledge regarding endothelial glycocalyx damage and ischemia-reperfusion injury.(au)

Endothelial glycocalyx as a potential theriapeutic target in organ injuries / 中华医学杂志(英文版)

OBJECTIVE@#The endothelial glycocalyx (eGC) is a dynamic and multicomponent layer of macromolecules found at the surface of vascular endothelium, which is largely underappreciated. It has recently been recognized that eGC is a major regulator of endothelial function and may have therapeutic value in organ injuries. This study aimed to explore the role of the eGC in various pathologic and physiologic conditions, by reviewing the basic research findings pertaining to the detection of the eGC and its clinical significance. We also explored different pharmacologic agents used to protect and rebuild the eGC.@*DATA SOURCES@#An in-depth search was performed in the PubMed database, focusing on research published after 2003 with keywords including eGC, permeability, glycocalyx and injuries, and glycocalyx protection.@*STUDY SELECTION@#Several authoritative reviews and original studies were identified and reviewed to summarize the characteristics of the eGC under physiologic and pathologic conditions as well as the detection and protection of the eGC.@*RESULTS@#The eGC degradation is closely associated with pathophysiologic changes such as vascular permeability, edema formation, mechanotransduction, and clotting cascade, together with neutrophil and platelet adhesion in diverse injury and disease states including inflammation (sepsis and trauma), ischemia-reperfusion injury, shock, hypervolemia, hypertension, hyperglycemia, and high Na as well as diabetes and atherosclerosis. Therapeutic strategies for protecting and rebuilding the eGC should be explored through experimental test and clinical verifications.@*CONCLUSIONS@#Disturbance of the eGC usually occurs at early stages of various clinical pathophysiologies which can be partly prevented and reversed by protecting and restoring the eGC. The eGC seems to be a promising diagnostic biomarker and therapeutic target in clinical settings.

Dexamethasone protects the glycocalyx on the kidney microvascular endothelium during severe acute pancreatitis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVE@#This study demonstrated that dexamethasone (DEX) protects the endothelial glycocalyx from damage induced by the inflammatory stimulus tumor necrosis factor-α (TNF-α) during severe acute pancreatitis (SAP), and improves the renal microcirculation.@*METHODS@#Ninety mice were evenly divided into 3 groups (Sham, SAP, and SAP+DEX). The SAP mice model was established by ligature of pancreatic duct and intraperitoneal injection of cerulein. Renal perfusion and function, and morphological changes of the glycocalyx were evaluated by laser Doppler velocimetry, electron microscopy, and histopathology (hematoxylin and eosin (H&E) staining), respectively. Serum levels of syndecan-1 and TNF-α were assessed by enzyme-linked immunosorbent assay (ELISA). The protective effects of dexamethasone on the glycocalyx and renal microcirculation were evaluated.@*RESULTS@#Significantly high levels of serum TNF-α were detected 3 h after the onset of SAP. These levels might induce degradation of the glycocalyx and kidney hypoperfusion, resulting in kidney microcirculation dysfunction. The application of dexamethasone reduced the degradation of the glycocalyx and improved perfusion of kidney.@*CONCLUSIONS@#Dexamethasone protects the endothelial glycocalyx from inflammatory degradation possibly initiated by TNF-α during SAP. This is might be a significant discovery that helps to prevent tissue edema and hypoperfusion in the future.

Effect of ulinastatin on perioperative glycocalyx and lung function in patients undergoing mitral valve replacement surgery / 中南大学学报(医学版)

To explore the effect of ulinastatin on perioperative glycocalyx and lung function in patients undergoing mitral valve replacement surgery.
 Methods: Fourty patients, undergoing mitral valve replacement, were randomly allocated into a control group and an ulinastatin group, which were administrated 50 mL normal saline or 2×104 U/kg ulinastatin at the beginning of cardiopulmonary bypass (CPB), respectively. The radical artery blood was collected at 4 time points: After induction of anesthesia (T0), at 10 min after the start of CPB (T1), 1 h after the end of CPB (T2), and 8 h after operation. The concentration of syndecan-1 and TNF-α in blood was measured. Moreover, the blood gas analysis was preformed and the oxygen index (OI) and difference in alveolar arterial oxygen partial pressure (PA-aO2) were calculated at T0, T2, and T3.
 Results: There were no significant difference between the 2 groups in OI, PA-aO2, and the concentration of syndecan-1 and TNF-α at T0 (P>0.05). The concentration of syndecan-1 and TNF-α was significantly increased at T1 and T2 in the 2 groups, and reached peak at T2. Compared with the control group, the concentration of syndecan-1 and TNF-α was decreased in the ulinastatin group at T1, T2, and T3 (P<0.05). Compared with T0, OI was lower and PA-aO2 was higher at T2 and T3 in both groups, but the 2 indexes were improved in the ulinastatin group compared with those in the control group (P<0.05).
 Conclusion: Ulinastatin can improve the post-operative pulmonary ventilation function in patients with mitral valve replacement. The mechanism may be associated with the inhibition of TNF-α release and the reduction of glycocalyx shedding induced by ulinastatin.

Perioperative implication of the endothelial glycocalyx / 대한마취과학회지

The endothelial glycocalyx (EG) is a gel-like layer lining the luminal surface of healthy vascular endothelium. Recently, the EG has gained extensive interest as a crucial regulator of endothelial funtction, including vascular permeability, mechanotransduction, and the interaction between endothelial and circulating blood cells. The EG is degraded by various enzymes and reactive oxygen species upon pro-inflammatory stimulus. Ischemia-reperfusion injury, oxidative stress, hypervolemia, and systemic inflammatory response are responsible for perioperative EG degradation. Perioperative damage of the EG has also been demonstrated, especially in cardiac surgery. However, the protection of the EG and its association with perioperative morbidity needs to be elucidated in future studies. In this review, the present knowledge about EG and its perioperative implication is discussed from an anesthesiologist's perspective.

Dose and timing of normal saline resuscitation on endothelial glycocalyx in early septic shock / 中华危重病急救医学

OBJECTIVE@#To observe the effect of different doses and timing of normal saline (NS) resuscitation combined with norepinephrine (NE) on endothelial glycocalyx in rabbits with early septic shock.@*METHODS@#Thirty New Zealand male rabbits were randomly divided into sham group, model group, 30 mL and 60 mL timely resuscitation groups (30 mL and 60 mL timely group), and 30 mL delayed resuscitation group (30 mL delayed group) with 6 rabbits in each group. The rabbit model of septic shock was reproduced by cecal ligation and puncture (CLP). The rabbits in sham group were only received abdominal cavity open without cecal and ligation. The rabbits in 30 mL and 60 mL timely groups and 30 mL delayed group were intravenous infused with 30 mL/kg or 60 mL/kg NS immediately or 1 hour after model reproduction for 1 hour, and the mean arterial pressure (MAP) was maintained over 75 mmHg (1 mmHg = 0.133 kPa) compared with intravenous pumping of 0.02-0.05 μg×kg-1×min-1 NE followed by 5 mL/h NS infusion till the end of the experiment. The rabbits in sham and model groups were only given 5 mL/h NS. The changes in arterial blood gas before and immediately after resuscitation were observed in three fluid resuscitation groups. The internal jugular vein blood was collected at 0, 3, 6 hours after model reproduction. The levels of syndecan-1 (polysaccharide envelope marker) in plasma were determined by enzyme linked immunosorbent assay (ELISA). The rabbits were sacrificed at 6 hours after model reproduction, and the lung tissue was harvested. Western Blot was used to determine the protein expressions of intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase 2 (MMP-2) and syndecan-1. The positive expression of syndecan-1 in lung tissue was observed by immunohistochemical method.@*RESULTS@#(1) Blood gas analysis: compared with the results before resuscitation, the levels of lactic acid (Lac) after resuscitation in three fluid resuscitation groups were significantly decreased, especially in 30 mL timely group; the central venous blood oxygen saturation (ScvO2) was significantly increased, especially in 30 mL delayed group. Oxygenation index (PaO2/FiO2) was improved in 30 mL timely and 30 mL delayed resuscitation groups, which was decreased in 60 mL delayed group. (2) Plasma marker: compared with sham group, plasma syndecan-1 level in model group was significantly increased with a time-dependent manner. Plasma syndecan-1 levels at 3 hours in 30 mL timely and 30 mL delayed groups were significantly decreased as compared with those of model group (ng/L: 138.0±2.4, 139.7±15.7 vs. 161.5±4.1, both P < 0.05), but it was significantly increased at 6 hours in 30 mL delayed group (ng/L: 213.1±19.4 vs. 206.4±15.5, P < 0.05). The plasma syndecan-1 levels at 3 hours and 6 hours in 60 mL timely group were significantly higher than those in model group (ng/L: 233.0±28.9 vs. 161.5±4.1, 252.3±27.2 vs. 206.4±15.5, both P < 0.05). (3) Protein expression in lung tissue: compared with sham group, the protein expressions of ICAM-1 and MMP-2 in lung tissue of model group were significantly increased, and syndecan-1 protein expression was significantly decreased. After 30 mL timely or 30 mL delayed resuscitation, the protein expressions of ICAM-1 and MMP-2 in lung tissue were significantly decreased, and syndecan-1 protein expression was significantly increased, especially in 30 mL timely group, which showed statistical differences as compared with those of model group (ICAM-1 protein: 0.56±0.09 vs. 1.04±0.05, MMP-2 protein: 0.83±0.15 vs. 1.06±0.06, syndecan-1 protein: 2.09±0.08 vs. 0.99±0.03, all P < 0.05). The change tendency of protein expressions in 60 mL timely group was opposite to the other two resuscitation groups. (4) Immunohistochemistry: the positive expression of syndecan-1 in lung tissues was significant in the sham group, and it was lowered in model group. The positive expression of syndecan-1 was increased after 30 mL timely or 30 mL delayed resuscitation, but further weakened in 60 mL timely group.@*CONCLUSIONS@#The dose and timing of resuscitation with NS in septic shock can affect pulmonary vascular endothelial glycocalyx function. The timely resuscitation with 30 mL NS in combination with NE plays a protective effect on endothelial cell and glycocalyx. However, NS resuscitation which was not timely or excessive infusion can make the glycocalyx degradation more obvious, resulting in increased endothelial permeability, microcirculation damaged, thus aggravate lung injury.

Salt Sensitivity and Hypertension: A Paradigm Shift from Kidney Malfunction to Vascular Endothelial Dysfunction

Hypertension is a complex trait determined by both genetic and environmental factors and is a major public health problem due to its high prevalence and concomitant increase in the risk for cardiovascular disease. With the recent large increase of dietary salt intake in most developed countries, the prevalence of hypertension increases tremendously which is about 30% of the world population. There is substantial evidence that suggests some people can effectively excrete high dietary salt intake without an increase in arterial BP, and another people cannot excrete effectively without an increase in arterial BP. Salt sensitivity of BP refers to the BP responses for changes in dietary salt intake to produce meaningful BP increases or decreases. The underlying mechanisms that promote salt sensitivity are complex and range from genetic to environmental influences. The phenotype of salt sensitivity is therefore heterogeneous with multiple mechanisms that potentially link high salt intake to increases in blood pressure. Moreover, excess salt intake has functional and pathological effects on the vasculature that are independent of blood pressure. Epidemiologic data demonstrate the role of high dietary salt intake in mediating cardiovascular and renal morbidity and mortality. Almost five decades ago, Guyton and Coleman proposed that whenever arterial pressure is elevated, pressure natriuresis enhances the excretion of sodium and water until blood volume is reduced sufficiently to return arterial pressure to control values. According to this hypothesis, hypertension can develop only when something impairs the excretory ability of sodium in the kidney. However, recent studies suggest that nonosmotic salt accumulation in the skin interstitium and the endothelial dysfunction which might be caused by the deterioration of vascular endothelial glycocalyx layer (EGL) and the epithelial sodium channel on the endothelial luminal surface (EnNaC) also play an important role in nonosmotic storage of salt. These new concepts emphasize that sodium homeostasis and salt sensitivity seem to be related not only to the kidney malfunction but also to the endothelial dysfunction. Further investigations will be needed to assess the extent to which changes in the sodium buffering capacity of the skin interstitium and develop the treatment strategy for modulating the endothelial dysfunction.

Importancia médica del glucocáliz endotelial: Parte 2: su papel en enfermedades vasculares y complicaciones de la diabetes mellitus / Medical significance of endothelial glycocalyx: Part 2: Its role in vascular diseases and in diabetic complications

El glucocáliz endotelial es una capa constituida por glucosaminoglicanos, proteoglicanos y glucoproteínas que cubre al endotelio en su cara luminal. La participación del deterioro del glucocáliz endotelial parece esencial en los pasos iniciales de la fisiopatología de la aterosclerosis, de las complicaciones microangiopáticas de la diabetes mellitus y de la enfermedad venosa crónica. Los factores de riesgo de la aterosclerosis como la hipercolesterolemia, la hiperglucemia, la inflamación, el exceso de sodio y las fuerzas de tensión alteradas causan deterioro del glucocáliz. Esto provoca disfunción endotelial y permite la filtración de lipoproteínas (LDL) y de leucocitos al espacio subendotelial, iniciando la formación de la placa de ateroma. En la diabetes el glucocáliz adelgazado, principalmente por estrés oxidativo, posibilita la filtración de proteínas (albuminuria) y el trastorno endotelial de la microangiopatía. La hipertensión venosa crónica altera las fuerzas de tensión y daña el glucocáliz, lo que permite la filtración de leucocitos a las partes más profundas de la pared venosa, iniciando la inflamación y el deterioro morfológico y funcional de las venas que lleva a la enfermedad venosa crónica. El tratamiento con glucosaminoglicanos (sulodexida) logra prevenir o revertir el daño al glucocáliz endotelial y algunas de sus consecuencias; es eficaz en la enfermedad venosa crónica, especialmente con úlceras venosas. También ha sido útil en aterosclerosis obliterante de miembros inferiores y en la nefropatía diabética con albuminuria.

Endothelial glycocalyx is a layer composed by glycosaminoglycans, proteoglycans and glycoproteins attached to the vascular endothelial luminal surface. Shredding of glycocalyx appears as an essential initial step in the pathophysiology of atherosclerosis and microangiopathic complications of diabetes mellitus, as well as in chronic venous disease. Atherosclerosis risk factors, as hypercholesterolemia (LDL), hyperglycemia, inflammation, salt excess and altered shear stress can damage glycocalyx. This lead to endothelial dysfunction and allows LDL and leukocytes to filtrate to the subendothelial space initiating atheroma plaque formation. Degradation of glycocalyx in diabetes mellitus is mainly due to oxidative stress and enables protein filtration (albuminuria) and endothelial disorder of microangiopathy. Chronic venous hypertension brings to altered shears stress which results in shredded glycocalyx, this allows leukocytes to migrate into venous wall and initiate inflammation leading to morphologic and functional venous changes of the chronic venous disease. Treatment with glycosaminoglycans (sulodexide) prevents or recovers the damaged glycocalyx and several of its consequences. This drug improves chronic venous disease and promotes healing of chronic venous ulcers. It has also been useful in peripheral arterial obstructive disease and in diabetic nephropathy with albuminuria.

Paradoxo do cálcio - o que temos a temer? / The calcium paradox - What should we have to fear?

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.

The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.

Recent findings on the use of hydroxyethyl starch

There has long been a controversy on the use of colloids. Many developments have now been made in the theological aspects. The new glycocalyx model and other related studies have shown that the volume expansion effect of colloids is not so superior to crystalloids in many situations. Moreover, the results from several multicenter studies on septic shock patients indicated that hydroxyethyl starch did not improve clinical outcome, but instead, increased the number of serious complications such as death and renal failure. Accordingly, this long debate has been concluded, at least about the use of hydroxyethyl starch colloid on patients with septic shock. Although there is still a lack of studies on perioperative patients, care is also needed when using colloids in their treatment.

Newly-synthesized chalcones-inhibition of adherence and biofilm formation of methicillin-resistant Staphylococcus aureus

Biofilm formation and adherence of bacteria to host tissue are one of the most important virulence factors of methicillin-resistant strains of Staphylococcus aureus (MRSA). The number of resistant strains is seriously increasing during the past years and bacteria have become resistant, not only to methicillin, but also to other commonly used antistaphylococcal antibiotics. There is a great need for discovering a novel antimicrobial agent for the treatment of staphylococcal infections. One of the most promising groups of compounds appears to be chalcones. In present study we evaluated the in vitro effect of three newly synthesized chalcones: 1,3-Bis-(2-hydroxy-phenyl)-propenone, 3-(3Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone and 3-(4-Hydroxy-phenyl)-1-(2-hydroxyphenyl)-propenone on glycocalyx production, biofilm formation and adherence to human fibronectin of clinical isolates and laboratory control strain of MRSA (ATCC 43300). Subinhibitory concentrations of the tested compounds reduced the production of glycocalyx, biofilm formation and adherence to human fibronectin of all MRSA strains. Inhibition of biofilm formation was dose dependent and the most effective was 1,3-Bis-(2-hydroxy-phenyl)-propenone. In our study we demonstrated that three newly-synthesized chalcones exhibited significant effect on adherence and biofilm formation of MRSA strains. Chalcones may be considered as promising new antimicrobial agents that can be used for prevention of staphylococcal infections or as adjunct to antibiotics in conventional therapy.

Metastasis via Peritumoral Lymphatic Dilation in Oral Squamous Cell Carcinoma / 대한악안면성형재건외과학회지

PURPOSE: Nodal metastasis is the main prognostic factor in the patients with oral squamous cell carcinoma (OSCC). We investigated the association between tumor-associated lymphatics and OSCC characteristics. METHODS: Thirty-four specimens were used for the immunohistochemical staining with the antibody for vascular endothelial growth factor (VEGF)-C, VEGF-D, VEGF receptor (VEGFR)-3, phosphorylated VEGFR-3, D2-40, and matrix metallproteinases (MMPs). We observed the distribution of the lymphangiogenic factors and quantified the degree of expression. We determined lymphatic vessel density (LVD) and lymphatic vessel dilatation with D2-40 immunostaining. We assessed the association of LVD or lymphatic vessel dilatation with tumor progression or tumor differentiation. RESULTS: OSCC cells expressed lymphangiogenic ligands. Lymphangiogenic receptor, VEGFR-3, was expressed and activated in some tumor cells as well as in tumor-associated endothelial cells. LVD was not associated with tumor size or nodal status, but lymphatic vessel dilatation was higher in tumors with nodal metastasis, and also higher in poorly differentiated tumors. In stromal area of OSCC, MMP-1 and MMP-10 were up-regulated and the basement membrane of tumor-associated endothelial cells was destroyed by these collagenases. CONCLUSION: In the primary tumors with nodal metastasis, especially in poorly differentiated OSCC, tumor cells invaded the dilated lymphatic vessels via ruptured sites. MMP-1 and MMP-10 are important in the lysis of the glycocalyx inside the tumor-associated lymphatic endothelial cells.

Importancia médica del glucocáliz endotelial / Medical significance of endothelial glycocalyx

El glucocáliz endotelial es una capa constituida por glucosaminoglicanos, proteoglicanos y glucoproteínas que cubre al endotelio vascular en su cara luminal. Tiene múltiples funciones: transducción de las fuerzas mecánicas de tensión, regulación de la permeabilidad vascular de líquidos y moléculas y de la activación de la coagulación y de la fibrinólisis, protege de la adhesión de leucocitos y plaquetas al endotelio. En general, el glucocáliz protege a la pared vascular de ataques patogénicos. La lesión del glucocáliz puede ocurrir por fuerzas de tensión anormales, especies reactivas de oxígeno, hipernatremia, hiperglucemia, hipercolesterolemia y moléculas inflamatorias, lo que causa disfunción endotelial, incremento en la permeabilidad, filtración de lipoproteínas al subendotelio, activación de la coagulación e incremento de la adherencia de leucocitos y plaquetas al endotelio vascular. La participación del deterioro del glucocáliz endotelial puede ser importante en la fisiopatología de diversas enfermedades vasculares.

Endothelial glycocalyx is a layer composed by glycosaminoglycans, proteoglycans and glycoproteins attached to the vascular endothelial luminal surface. It has several physiological roles: shear stress mechanotransduction to the endothelial cells, regulation of fluids and macromolecules vascular permeability, of coagulation cascade activation and fibrinolysis, and protects the endothelium from platelets and leukocytes adhesion. In general, glycocalyx protects vascular wall against pathogenic insults. The glycocalyx may be damaged by abnormal shear stress, reactive oxygen species, hypernatremia, hyperglycemia, hypercholesterolemia and inflammatory molecules, resulting in endothelial dysfunction, enhanced vascular permeability, lipoproteins leakage to subendothelial space, activation of plasma coagulation, and increased adherence of platelets and leukocytes to the endothelial cells. Shredding of glycocalyx appears as an important initial step in the pathophysiology of vascular diseases.

[Effects of estrogen progesterone on endometrial glycocalyx expression in superovulated mice in the implantation window time]

It has been reported that apical glycocalyx expression of uterine affects embryo implantation. The aim of this study was to determine endometrial glycocalyx and endometrial thickness after estrogen and progesterone injection in hyperstimulated mice at luteal phase. Adult male and female mice were used for induction of pesudopregnancy. The mice were divided into two groups experimental and control groups. Female mice in the experimental group were superovulated and were then mated with vasectomised mice to induce psudopregnancy Experimental group based on hormone injection was subdivided into five groups 1] Estrogen, 2] Progesterone, 3] Estrogen + Progesterone, 4] Antiprogesterone + Estrogen, 5] Sham. Pesudopregnancy in the control group was achieved without any hyperstimulation. The uterines of all groups were collected after 4.5 days of pregnancy and prepared for the assessment of endometrial thickness and endometrial glycocalyx expression. The results showed that estrogen and progesterone injection increased the intensity of PAS reaction, whereas progesterone decreased this. Also our results showed that the endometrial thickness in the sham group was the highest and in the progesterone group was the lowest Our results showed that addition of estrogen to progesterone, compared to P supplementation alone, provided appropriate endometrial conditions to embryo implantation. Hence combination of estrogen and progesterone injection as luteal support hormones can be used in IVF protocols

Ultrastructure of the adhesion of bacteria to the epithelial cell membrane of three-day postnatal rat tongue mucosa: a transmission and high-resolution scanning electron microscopic study

Togue mucosa surface of 3-day postnatal rats was examined under transmission electron microscopy (TEM) and high-resolution scanning electron microscopy (HRSEM). For HRSEM analysis, the specimens were fixed in the same solution for 24 h, postfixed in 2 percent osmiun tetroxide, critical-point dried and coated with platinum-palladium. For TEM analysis, the specimens were fixed using modified Karnovsky solution and embedded in Spurr resin. The results revealed the presence of numerous microplicae in the membrane surface of keratinized epithelial cells to which groups of bacteria were attached. These bacteria were staphylococcus and coccus organized either in rows or at random, which were visualized in three-dimensional HRSEM images. At high magnification, the TEM images revealed the adhesion of bacteria to the cell membrane through numerous filamentous structures comprising the glycocalyx. The fine fibrillar structures rising from each bacterium and from cell membrane were clearly seen. These characteristics on bacteria structure may be used for future control or prevention of bacterial diseases and for installation of the oral native flora.

A superfície lingual de ratos de três dias de idade foi examinada em microscópia eletrônica de transmissão (MET) e em microscópia eletrônica varredura de alta resolução (MEVAR). Para o método de MEVAR, os espécimes foram fixados na mesma solução por 24 h, pós fixados em solução de tetróxido de ósmio a 2 por cento, secos em ponto crítico e cobertos com platina- paládio. Para análise em MET, os espécimes foram fixados utilizando-se solução de Karnovsky modificada e emblocadas em resina Spurr. Os resultados mostraram a presença de numerosas micropregas na membrana superficial das células epiteliais queratinizadas, nas quais estavam aderidos grupos de bactérias. Estas bactérias eram estafilococos e cocos, organizados em fileiras ou a esmo, e puderam ser observadas em imagens tri-dimensionais em MEVAR. Em maiores aumentos, as imagens em MET revelaram a adesão de bactérias nas células por meio de numerosas estruturas filamentares compondo o glicocálice. As delicadas estruturas filamentares na periferia das bactérias e das células foram nitidamente identificadas. Estas características da estrutura bacteriana podem ser utilizadas, no futuro, para controle e prevenção de doenças bacteriana, bem como para a instalação da flora oral nativa.

Experimental study of peripheral nerve regeneration by using non-tubular natural cellulose membrane nerve conduit

Styela clava, called non-native tunicate or sea squirt, is habitat which include bays and harbors in Korea and several sites in the sea faced world. We fabricate cellulose membrane nerve conduit (CMNC) from this native sea squirt skin, and evaluate the capacity of promoting peripheral nerve regeneration in the rat sciatic nerve defect model. After processing the pure cellulose membrane from the sea squirt skin as we already published before, CMNC was designed as a non-tubular sheet with 14 mm length and 4 mm width. Total eleven male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into sham group (n=2), silicone tube grafted control group (n=3) and experimental group (n=6). Each CMNC grafted nerve was evaluated after 4, 8 and 12 weeks in the experimental group, and after 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were all examined using image analyzer and electromicroscopic methods in the all groups. The regenerated axon and nerve sheath were found only in the inner surface of the CMNC after 4 weeks and became more thicker after 8 and 12 weeks. In the TEM study, CMNC grafted group showed more abundant organized myelinated nerve fibers with thickened extracellular matrix than silicone conduit grafted group after 12 weeks. The sciatic function index (SFI) and ankle stance angle (ASA) in the functional evaluation were -47.2+/-3.9, 35.5.+/-4.9.in CMNC grafted group (n=2) and -80.4+/-7.4, 29.2.+/-5.3.in silicone conduit grafted group (n=3), respectively. And the myelinated axon was 41.59% in CMNC group and 9.51% in silicone conduit group to the sham group. The development of a bioactive CMNC to replace autogenous nerve grafts offers a potential and available approach to improved peripheral nerve regeneration. As we already published before, small peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx, induced the effective axonal regeneration with rapid growth of Schwann cells beneath the inner surface of CMNC. So the possibilities of clinical application as a peripheral nerve regeneration will be able to be suggested.

Alcaligenes faecalis kw-a biofilm for denitrification of nitrate-rich effluent.

Alcaligenes faecalis kw-A selected for possessing good denitrification efficiency was used for biofilm development. The biofilm could be developed on a glass surface within 12 hr when 5%, Ix 10(8) cells/ml was used as inoculum. The microcolonies were seen in 6 hr and glycocalyx in 9 hr stage. At 24 hr the biofilm was developed fully and hence was visualised as dense mass. The biofilm protein content showed 48.5% increase in shake flask than in static condition. The exopoplymer is produced in larger amounts in biofilm as compared to the suspended cells. Also, its amount was more by 43% in the biofilm produced in shake flask condition than in static condition. The biofilm could remove 95% nitrate from nitrate-rich effluent in a bench-scale process in 36 hr. The attached growth technique demonstrated here can be utilised to study the effect of favourable as well as adverse conditions on the denitrification efficiency of a culture. The ultimate application of a denitrifying biofilm would be in attached growth or biofilm reactor.