Artery-Associated Sympathetic Innervation Drives Rhythmic Vascular Inflammation of Arteries and Veins.

BACKGROUND: The incidence of acute cardiovascular complications is highly time-of-day dependent. However, the mechanisms driving rhythmicity of ischemic vascular events are unknown. Although enhanced numbers of leukocytes have been linked to an increased risk of cardiovascular complications, the role that rhythmic leukocyte adhesion plays in different vascular beds has not been studied. METHODS: We evaluated leukocyte recruitment in vivo by using real-time multichannel fluorescence intravital microscopy of a tumor necrosis factor-α-induced acute inflammation model in both murine arterial and venous macrovasculature and microvasculature. These approaches were complemented with genetic, surgical, and pharmacological ablation of sympathetic nerves or adrenergic receptors to assess their relevance for rhythmic leukocyte adhesion. In addition, we genetically targeted the key circadian clock gene Bmal1 (also known as Arntl) in a lineage-specific manner to dissect the importance of oscillations in leukocytes and components of the vessel wall in this process. RESULTS: In vivo quantitative imaging analyses of acute inflammation revealed a 24-hour rhythm in leukocyte recruitment to arteries and veins of the mouse macrovasculature and microvasculature. Unexpectedly, although in arteries leukocyte adhesion was highest in the morning, it peaked at night in veins. This phase shift was governed by a rhythmic microenvironment and a vessel type-specific oscillatory pattern in the expression of promigratory molecules. Differences in cell adhesion molecules and leukocyte adhesion were ablated when disrupting sympathetic nerves, demonstrating their critical role in this process and the importance of ß2-adrenergic receptor signaling. Loss of the core clock gene Bmal1 in leukocytes, endothelial cells, or arterial mural cells affected the oscillations in a vessel type-specific manner. Rhythmicity in the intravascular reactivity of adherent leukocytes resulted in increased interactions with platelets in the morning in arteries and in veins at night with a higher predisposition to acute thrombosis at different times as a consequence. CONCLUSIONS: Together, our findings point to an important and previously unrecognized role of artery-associated sympathetic innervation in governing rhythmicity in vascular inflammation in both arteries and veins and its potential implications in the occurrence of time-of-day-dependent vessel type-specific thrombotic events.

Application of a Novel Murine Ear Vein Model to Evaluate the Effects of a Vascular Radioprotectant on Radiation-Induced Vascular Permeability and Leukocyte Adhesion.

Vascular injury after radiation exposure contributes to multiple types of tissue injury through a cascade of events. Some of the earliest consequences of radiation damage include increased vascular permeability and promotion of inflammation, which is partially manifested by increased leukocyte-endothelial (L/E) interactions. We describe herein a novel intravital imaging method to evaluate L/E interactions, as a function of shear stress, and vascular permeability at multiple time points after local irradiation to the ear. This model permitted analysis of quiescent vasculature that was not perturbed by any surgical manipulation prior to imaging. To evaluate the effects of radiation on vascular integrity, fluorescent dextran was injected intravenously and its extravasation in the extravascular space surrounding the ear vasculature was measured at days 3 and 7 after 6 Gy irradiation. The vascular permeability rate increased approximately twofold at both days 3 and 7 postirradiation ( P < 0.05). Leukocyte rolling, which is indicative of L/E interactions, was significantly increased in mice at 24 h postirradiation compared to that of nonirradiated mice. To assess our model, as a means for assessing vascular radioprotectants, we treated additional cohorts of mice with a thrombopoietin mimetic, TPOm (RWJ-800088). In addition to stimulating platelet formation, thrombopoietin can protect vasculature after several forms of injury. Thus, we hypothesized that TPOm would reduce vascular permeability and L/E adhesion after localized irradiation to the ear vasculature of mice. If TPOm reduced these consequences of radiation, it would validate the utility of our intravital imaging method. TPOm reduced radiation-induced vascular leakage to control levels at day 7. Furthermore, L/E cell interactions were also reduced in irradiated mice treated with TPOm, compared with mice receiving irradiation alone, particularly at high shear stress ( P = 0.03, Kruskal-Wallis). We conclude that the ear model is useful for monitoring quiescent normal tissue vascular injury after radiation exposure. Furthermore, the application of TPOm, for preventing early inflammatory response created by damage to vascular endothelium, suggests that this drug may prove useful in reducing toxicities from radiotherapy, which damage microvasculature that critically important to tissue function.

Extravillous trophoblast invasion of venous as well as lymphatic vessels is altered in idiopathic, recurrent, spontaneous abortions.

STUDY QUESTION: Do extravillous trophoblasts (EVTs) invade non-arterial decidual vessels in healthy and pathological pregnancies? SUMMARY ANSWER: Our results reveal that trophoblast invasion of venous and lymphatic vessels is a frequent event during the first trimester of pregnancy and is compromised in  recurrent spontaneous abortion (RSA). In addition, the present data suggest that EVTs populate regional lymph nodes during pregnancy. WHAT IS ALREADY KNOWN: Human trophoblasts remodel and invade decidual spiral arteries. In addition, a recent report demonstrates that trophoblasts contact and invade decidual veins. STUDY DESIGN, SIZE, DURATION: Tissue samples of human first trimester deciduae basalis (n = 54, 6th-13th weeks of gestation) obtained from elective pregnancy terminations were used to study trophoblast invasion into veins and lymphatics, in comparison to arteries. Age-matched cases of idiopathic, recurrent spontaneous abortions tissue samples (n = 23) were assessed for cell numbers of EVTs in these decidual vessels. In addition, lymph nodes of four pregnant women were analysed for the presence of EVTs. PARTICIPANTS/MATERIALS, SETTING, METHODS: Localization, frequency and EVT-mediated targeting and invasion of arterial, venous as well as lymphatic vessels were determined in first trimester decidua basalis tissue sections using immunofluorescence staining with antibodies against CD31, CD34, ephrin B2 (EFNB2), ephrin receptor B4 (EPHB4), HLA-G, podoplanin, prospero-related homeobox 1 (Prox-1), alpha-smooth muscle actin 2 (ATCTA2), von willebrand factor (vWF) and proteoglycan 2 (PRG2). Arterial, venous and lymphatic-associated EVTs were further characterized according to their position in the vascular structure and classified as intramural (im) or intraluminal (il). MAIN RESULTS AND THE ROLE OF CHANCE: EVTs, specifically expressing PRG2, target and invade veins and lymphatics in first trimester decidua basalis since HLA-G+ trophoblast were detected in the vascular wall (intramural EVT, imEVTs) and in the lumen of these vessels (intraluminal EVT, ilEVTs). In total, 276 arteries, 793 veins and 113 lymphatics were analysed. While EVTs contact and invade arteries and veins to a similar extent we found that lymphatics are significantly less affected by EVTs (P = 0.001). Moreover, ilEVTs were detected in the lumen of venous and lymphatic vessels, whereas ilEVTs were only found occasionally in the lumen of arteries. Interestingly, RSA tissue sections contained significantly more arterial (P = 0.037), venous (P = 0.002) and lymphatic vessels (P < 0.001), compared to healthy controls. However, while RSA-associated arterial remodeling was unchanged (P = 0.39) the ratios of EVT-affected versus total number of veins (P = 0.039) and lymphatics (P < 0.001) were significantly lower in RSA compared to age-matched healthy decidual sections. Finally, HLA-G+/PRG2+/CD45-EVTs can be detected in regional lymph nodes of pregnant women diagnosed with cervical cancer. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: In this study, first trimester decidual tissues from elective terminations of pregnancies have been examined and used as a reference for healthy pregnancy. However, this collective may also include pregnancies which would have developed placental disorders later in gestation. Due to limitations in tissue availability our staining results for EVT-specific marker expression in regional lymph nodes of pregnant women are based on four cases only. WIDER IMPLICATIONS OF THE FINDINGS: In this study, we propose migration of HLA-G+ cells into regional lymph nodes during pregnancy suggesting that the human EVT is capable of infiltrating maternal tissues via the blood stream. Moreover, the description of compromised EVT invasion into the venous and lymphatic vasculature in RSA may help to better understand the pathological characteristics of idiopathic recurrent pregnancy loss. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Austrian Science Fund (grant P-25187-B13 to J.P. and grant P-28417-B30 to M.K.). There are no competing interests to declare.

New findings on venous thrombogenesis.

Venous thrombosis (VT) is the third most common cause of cardiovascular death worldwide. Complications from VT and pulmonary embolism are the leading cause of lost disability-adjusted life years. Risks include genetic (e.g., non-O blood group, activated protein C resistance, hyperprothrombinemia) and acquired (e.g., age, surgery, cancer, pregnancy, immobilisation, female hormone use) factors. Pathophysiologic mechanisms that promote VT are incompletely understood, but involve abnormalities in blood coagulability, vessel function, and flow (so-called Virchow's Triad). Epidemiologic studies of humans, animal models, and biochemical and biophysical investigations have revealed contributions from extrinsic, intrinsic, and common pathways of coagulation, endothelial cells, leukocytes, red blood cells, platelets, cell-derived microvesicles, stasis-induced changes in vascular cells, and blood rheology. Knowledge of these mechanisms may yield new therapeutic targets. Characterisation of mechanisms that mediate VT formation and stability, particularly in aging, are needed to advance understanding of VT.

Enhanced gene delivery in porcine vasculature tissue following incorporation of adeno-associated virus nanoparticles into porous silicon microparticles.

There is an unmet clinical need to increase lung transplant successes, patient satisfaction and to improve mortality rates. We offer the development of a nanovector-based solution that will reduce the incidence of lung ischemic reperfusion injury (IRI) leading to graft organ failure through the successful ex vivo treatment of the lung prior to transplantation. The innovation is in the integrated application of our novel porous silicon (pSi) microparticles carrying adeno-associated virus (AAV) nanoparticles, and the use of our ex vivo lung perfusion/ventilation system for the modulation of pro-inflammatory cytokines initiated by ischemic pulmonary conditions prior to organ transplant that often lead to complications. Gene delivery of anti-inflammatory agents to combat the inflammatory cascade may be a promising approach to prevent IRI following lung transplantation. The rationale for the device is that the microparticle will deliver a large payload of virus to cells and serve to protect the AAV from immune recognition. The microparticle-nanoparticle hybrid device was tested both in vitro on cell monolayers and ex vivo using either porcine venous tissue or a pig lung transplantation model, which recapitulates pulmonary IRI that occurs clinically post-transplantation. Remarkably, loading AAV vectors into pSi microparticles increases gene delivery to otherwise non-permissive endothelial cells.

Contribution of endothelial injury and inflammation in early phase to vein graft failure: the causal factors impact on the development of intimal hyperplasia in murine models.

OBJECTIVES: Autologous veins are preferred conduits in by-pass surgery. However, long-term results are hampered by limited patency due to intimal hyperplasia. Although mechanisms involved in development of intimal hyperplasia have been established, the role of inflammatory processes is still unclear. Here, we studied leukocyte recruitment and intimal hyperplasia in inferior vena cava grafts transferred to abdominal aorta in mice. METHODS AND RESULTS: Several microscopic techniques were used to study endothelium denudation and regeneration and leukocyte recruitment on endothelium. Scanning electron microscopy demonstrated denudation of vein graft endothelium 7 days post-transfer and complete endothelial regeneration by 28 days. Examination of vein grafts transferred to mice transgenic for green fluorescent protein under Tie2 promoter in endothelial cells showed regeneration of graft endothelium from the adjacent aorta. Intravital microscopy revealed recruitment of leukocytes in vein grafts at 7 days in wild type mice, which had tapered off by 28 days. At 28 and 63 days there was significant development of intimal hyperplasia. In contrast; no injury, leukocyte recruitment nor intimal hyperplasia occurred in arterial grafts. Leukocyte recruitment was reduced in vein grafts in mice deficient in E- and P-selectin. In parallel, intimal hyperplasia was reduced in vein grafts in mice deficient in E- and P-selectin and in wild type mice receiving P-selectin/E-selectin function-blocking antibodies. CONCLUSION: The results show that early phase endothelial injury and inflammation are crucial processes in intimal hyperplasia in murine vein grafts. The data implicate endothelial selectins as targets for intervention of vein graft disease.

Low levels of a natural IgM antibody are associated with vein graft stenosis and failure.

BACKGROUND: All humans have natural, protective antibodies directed against phosphorylcholine (PC) epitopes, a common inflammatory danger signal appearing at sites of cell injury, oxidative stress, and on bacterial capsules. In large human cohorts, low levels of anti-PC IgM were associated with a significantly increased risk of stroke or myocardial infarction. However, it is not known if these antibodies protect against the premature closure of arterial reconstructions. METHODS: A prospective, observational study of patients undergoing elective, infrainguinal, autogenous vein bypasses for atherosclerotic occlusive disease of the legs was conducted. Clinical data were recorded prospectively, and preoperative levels of anti-PC IgM measured with the CVDefine kit from Athera Biotechnologies (Solna, Sweden). The principal clinical end point was the loss of primary patency (loss of graft flow, or any intervention for stenosis). Patients were followed regularly by duplex ultrasound at 1, 3, 6, 12, 18 months, and yearly thereafter. RESULTS: Fifty-six patients were studied, for an average of 1.3 years. Indications for surgery were claudication (33.9%), ischemic rest pain (17.9%), and ischemia with ulceration or gangrene (48.2%). Seventeen (30.4%) patients experienced loss of primary patency (10 graft occlusions, seven surgical or endovascular revisions of graft stenoses). Kaplan-Meier survival analysis showed that the quartile of patients with the lowest anti-PC IgM levels had significantly worse primary graft patency (log-rank test, P = .0085). Uni- and multivariate Cox proportional hazards analysis revealed that the preoperative anti-PC IgM level was an important predictor of graft failure. Patients with IgM values in the lowest quartile had a 3.6-fold increased risk of graft failure (95% confidence interval: 1.1-12.1), even after accounting for other significant clinical or technical factors such as indication for surgery, site of distal anastomosis, or vein graft diameter. CONCLUSIONS: A naturally occurring IgM antibody directed against the proinflammatory epitope PC may be protective against vein graft stenosis and failure, through anti-inflammatory mechanisms. Measurement of this antibody may be a useful prognostic indicator, although larger studies of more diverse populations will be needed to confirm these results. The biological actions of anti-PC IgM suggest it may be useful in developing immunotherapies to improve bypass longevity.

Circulating inflammatory cells are associated with vein graft stenosis.

OBJECTIVE: Infrainguinal autogenous vein grafts are especially prone to narrowing and failure, and both inflammatory and thrombotic pathways are implicated. Platelets and monocytes are the key thrombo-inflammatory cells that arrive first at sites of vascular injury. These cells have potent interactions that recruit and activate one another, propagating thrombotic and inflammatory responses within the vessel wall. We therefore hypothesized that elevated levels of platelet-monocyte aggregates (PMA) might be associated with stenosis, and could possibly discriminate between patients with or without vein graft stenosis. METHODS: Thirty-six vascular surgery patients were studied, in a stable quiescent period after infrainguinal autogenous vein graft bypasses for occlusive disease. Eighteen patients had hemodynamically significant graft stenoses confirmed by imaging, and 18 were free from stenosis. The level of PMA in whole blood was quantified after blood draw using two-color flow cytometry. Three measurements were made per sample: the basal, in-vivo level of aggregates (baseline PMA); the predisposition to spontaneously generate PMA (spontaneous PMA); and PMA generation by the addition of exogenous thrombin receptor-activating peptide (stimulated PMA). The baseline, in-vivo level of PMA was estimated by immediate flow analysis. The predisposition to spontaneously generate PMA was measured after in vitro incubation. Responsiveness to thrombin stimulation of the blood was quantified by the in vitro dose response to an exogenous thrombin receptor-activating peptide (sfllrn). RESULTS: Baseline PMA levels were similar in patients with vein graft stenosis vs nonstenosis (14.8% ± 3.2 vs 10.1% ± 1.5, respectively, mean ± SEM). However, patients with stenosis showed higher spontaneous PMA levels (58.5% ± 4.5 vs 28.3% ± 4.3; P < .001) and higher stimulated PMA levels (P < .001; analysis of variance). Covariables of smoking, diabetes, statin, or antithrombotic therapy could not account for these differences. CONCLUSIONS: Platelet-monocyte reactivity may play a role in the development of vein graft stenoses. Those with/without stenosis differed primarily in their threshold, or predisposition to form aggregates (spontaneous PMA), while their basal circulating levels of PMA (baseline PMA) were similar. These measurements may unmask pathologic differences in thrombo-inflammatory responsiveness that are not apparent in basal measurements. Understanding the causes and mechanisms leading to abnormal platelet-monocyte responses may improve approaches to predicting or preventing vein graft stenosis.

Endotoxin-induced cardiovascular dysfunction in mice: effect of simvastatin.

Lung infections are associated with acute lung injury (ALI), systemic inflammation, and vascular events. Clinical studies suggest that statins improve health outcomes of patients with pneumonia and ALI. The mechanisms by which this occurs are unknown. The aim of this study was to determine whether statins attenuate systemic inflammation and cardiovascular dysfunction related to ALI in mice. Simvastatin (SS; 20 mg/kg) or vehicle solution was instilled intraperitoneally into mice 24 h before and again just prior to intratracheal LPS instillation (1 µg/g). These mice were then anesthetized with 2.0% isoflurane and underwent a short surgical procedure to instill LPS. Four hours later, IL-6 levels in bronchoalveolar lavage fluid and in arterial and venous serum were measured. Cardiac function was evaluated using 2-D echocardiography, and endothelial function was determined using wire myography on aortic sections. LPS induced a significant increase in serum IL-6 levels. SS reduced venous (P = 0.040) but not arterial concentrations of IL-6 (P = 0.112). SS improved the maximal vasodilatory response of the aorta to ACh (P = 0.004) but not to sodium nitroprusside (P = 1.000). SS also improved cardiac output (P = 0.023). Vasodilatory response to ACh was impaired when aorta from untreated mice was incubated with ex vivo IL-6 (P = 0.004), whereas in the aorta from mice pretreated with SS, the vasodilatory response did not change with IL-6 incubation (P = 0.387). SS significantly improved LPS-induced cardiovascular dysfunction possibly by reducing systemic expression of IL-6 and its downstream signaling pathways. These findings may explain how statins improve health outcomes in patients with ALI.

Follicular thyroid carcinoma invades venous rather than lymphatic vessels.

Follicular thyroid carcinoma (FTC) tends to metastasize to remote organs rather than local lymph nodes. Separation of FTC from follicular thyroid adenoma (FTA) relies on detection of vascular and/or capsular invasion. We investigated which vascular markers, CD31, CD34 and D2-40 (lymphatic vessel marker), can best evaluate vascular invasion and why FTC tends to metastasize via blood stream to remote organs. Thirty two FTCs and 34 FTAs were retrieved for evaluation. The average age of patients with FTA was 8 years younger than FTC (p = 0.02). The female to male ratio for follicular neoplasm was 25:8. The average size of FTC was larger than FTA (p = 0.003). Fourteen of 32 (44%) FTCs showed venous invasion and none showed lymphatic invasion, with positive CD31 and CD34 staining and negative D2-40 staining of the involved vessels. The average number of involved vessels was 0.88 +/- 1.29 with a range from 0 to 5, and the average diameter of involved vessels was 0.068 +/- 0.027 mm. None of the 34 FTAs showed vascular invasion. CD31 staining demonstrated more specific staining of vascular endothelial cells than CD34, with less background staining. We recommended using CD31 rather than CD34 and/or D2-40 in confirming/excluding vascular invasion in difficult cases. All identified FTCs with vascular invasions showed involvement of venous channels, rather than lymphatic spaces, suggesting that FTCs prefer to metastasize via veins to distant organs, instead of lymphatic vessels to local lymph nodes, which correlates with previous clinical observations.

The positive effect of immunosuppression on adaptation of venous allografts to arterialisation in rats.

OBJECTIVES AND DESIGN: We investigated whether immunosuppression was necessary for transplanted allogeneic veins to adapt to arterialisation. We used a transplant rat model with or without immunosuppression. MATERIAL AND METHODS: Iliolumbar veins from Lewis (LEW) or Brown-Norway (BN) rats were transplanted into the abdominal aorta of isogeneic (LEW to LEW; group A) or allogeneic (BN to LEW; groups B and C) rats. Group C had daily intramuscular injections of 0.2mgkg(-1) FK506. Light microscope evaluations of grafts were performed at 30 days following transplantation. We determined the presence of endothelial cells, the intensity of intimal proliferation and the degree of infiltration by Lewis major histocompatibility complex (MHC) class II positive, CD4-positive and CD8-positive cells into the adventitia. RESULTS: Groups A and C displayed similar results in intimal thickness (12.7+/-7.0microm vs. 15.0+/-8.4 mum, respectively) and degree of adventitial infiltration by MHC class II positive (16.6+/-7.5 vs. 14.6+/-6.2, respectively), CD8-positive (0.8+/-1.7 vs. 1.8+/-2.6, respectively) and CD4-positive (12.5+/-7.7 vs. 5.8+/-4.6, respectively) cells. In contrast, allogeneic rats without immunosuppression (group B) showed infiltration of host immunocompetent cells and destruction of the venous wall with no histological signs of arterialisation. CONCLUSION: Immunosuppressive therapy is necessary for venous allograft adaptation to arterialisation in rats.

Involvements of cysteinyl leukotrienes and nitric oxide in antigen-induced venodilatation of nasal mucosa in sensitized rats in vivo.

To determine an in vivo venodilatation of nasal mucosa, which is thought to be one of the causes of nasal obstruction in allergic rhinitis, venous diameters of nasal septa were directly measured in anesthetized rats. An application of antigen to nasal mucosa of sensitized rats caused an increase in diameters of mucosal veins, that is, venodilatation: the maximal response (about 20% increase in diameters) was observed at 55 min after antigen challenge. The antigen-induced increase in venous diameter of nasal mucosa was significantly inhibited by pretreatment with a cysteinyl leukotrienes (CysLTs) receptor antagonist, SR2640, and a nitric oxide (NO) synthase inhibitor, N(G)-monomethyl-L-arginine, indicating that CysLTs and NO might be involved in the venodilatation of nasal mucosa induced by antigen challenge. Blocking the action of CysLTs and NO might be therefore useful for the therapy of nasal obstruction in allergic rhinitis.

Accelerated immunopathological response of mice infected with Mycobacterium tuberculosis disrupted in the mce1 operon negative transcriptional regulator.

Mycobacterium tuberculosis causes a variety of clinical outcomes determined by host as well as bacterial factors. M. tuberculosis disrupted in the mce1 operon causes increased mortality in immunocompetent mice. This operon is negatively regulated by mce1R (Rv0165c). We studied the role of mce1R in infection outcome in mice. At 5 x 10(4) tail vein infectious dose, the median survival time (MST) of mice infected with the mce1R mutant M. tuberculosis H37Rv was 293 days, while mice infected with the wild-type H37Rv survived more than 350 days (P < 0.0001). At a higher dose (5 x 10(6)), the MST of mutant-infected mice was 32 days, compared with 127 days for wild type-infected mice (P < 0.0001). With either tail vein or aerosol infection, mutant-infected mice developed larger granulomatous lesions in their lungs than mice infected with the wild type. Mutant-infected mice were unable to control the bacterial burden in the first 4 weeks of infection, but even after achieving control later, these mice succumbed to granulomatous pneumonia. These observations suggest that the early deregulated expression of the mce1 operon products determines later granulomatous tissue response. mce1 operon may homeostatically regulate the cell wall architecture in vivo that elicits a steady-state granuloma tissue response permitting M. tuberculosis to establish a long-term infection.

Nitric oxide monocyte production levels in patients with the hepatosplenic form of Scistosoma mansoni infection who underwent splenectomy, ligature of the left gastric vein and auto implantation of spleen tissue in the major omentum / Níveis de óxido nítrico produzidos por monócitos em portadores de esquistossomose hepatoesplênica que se submeteram a esplenectomia, ligadura da veia gástrica esquerda e auto-implante de tecido esplênico no omento maior

PURPOSE: To measure the levels of NO production by monocytes in patients with the hepatosplenic form of schistosomiasis mansoni who underwent splenectomy, ligature of the left gastric vein and auto implantation of spleen tissue in the major omentum. METHODS: Four groups of volunteers were enrolled in the investigation: G1 - 12 patients with S. mansoni infection in its hepatosplenic form without any kind of treatment (SMH); G2 - 13 SMH patients who underwent medical treatment and portal hypertension decompression splenectomy and ligature of the left gastric vein (SMH/SLGV); G3 - 19 patients similar to the later group, but additionally received auto implantation of spleen morsels in the major omentum (SMH/SLGV/AI); and G4 - 15 individuals with no S. mansoni infection coming from the same geographical area and presenting similar socio economical status (CG). Nitrite production by monocytes was determined by a standard Griess reaction adapted to microplates. The results were presented by mean ± SD for each group. Significant differences in NO production by monocytes were determined by Tukey-Kramer multicomparisons test. Probability values of 0.05 were considered significant. RESULTS: Patients from G1 (SMH) showed lower level of NO production by monocytes (5.28 ± 1.28µmol/ml). Patients from G2 (SMH/SLGV) showed similar results (6.67 ± 0.44µmol/ml - q = 2.681 p > 0.05). Individuals of G4 (CG) showed higher level of NO production by monocytes (8.19 ± 2.74µmol/ml). Patients from G3 (SMH/SGLV/AI) showed similar NO production by PBMC as compared to individuals of G4 (CG) - (7.41 ± 1.65µmol/ml - q = 1.615 p > 0.05). The volunteers from G4 (CG) and G3 (SMH/SLGV/AI) showed significantly greater levels of NO production by monocytes as compared to those from G1 (SMH) - (q = 5.837 p < 0.01, and q = 4.285 p < 0.05). CONCLUSION: Collectively, the results point to a restoration of NO normal production by monocytes in SH...

OBJETIVO: Mensurar os níveis de produção de ON por monócitos do sangue periférico (MSP) em portadores de esquistossomose na forma hepatoesplênica que tinham se submetido a esplenectomia, ligadura da veia gástrica esquerda e auto-implante de tecido esplênico no omento maior. MÉTODOS: Quatro grupos de voluntários foram envolvidos na investigação: G1 - 12 portadores de esquistossomose hepatoesplênica sem nenhuma forma de tratamento (EHE); G2 - 13 portadores de EHE que receberam tratamento clínico e se submeteram cirurgia para descompressão do sistema porta esplenectomia e ligadura da veia gástrica esquerda (EHE/ELGE); G3 - 19 pacientes similares ao do último grupo, mas que receberam também auto-implante de fragmentos de tecido esplênico no omento maior (EHE/ELGE/AI); e G4 - 15 indivíduos sem infecção pelo S. mansoni advindos da mesma área geográfica e apresentando as mesmas condições sócio-econômicas (GC). A produção de ON pelos MSP foi determinada pela reação padrão de Griess, adaptada para poços em microplaca. Os resultados foram expressos por suas médias ± DP para cada grupo. Diferenças significantes nas medias de produção de ON pelos MSP foram determinadas pelo teste de comparações múltiplas de Tukey-Kramer. Foram aceito os limites de significância de p < 0,05. RESULTADOS: Os pacientes portadores de EHE não tratados (G1) evidenciaram os níveis mais baixos de produção de ON pelos MSP (5,28 ± 1,28µmol/ml). Os pacientes do G2 (EHE/ELGE) evidenciaram resultados similares (6,67 ± 0,44µmol/ml - q = 2,681 p > 0.05). Os indivíduos do G4 (GC) evidenciaram os mais altos níveis de produção de ON pelos MSP (8,19 ± 2,74µmol/ml). Os pacientes do G3 (EHE/ELGE/AI) evidenciaram produção de ON produzido pelos MSP similares aos indivíduos do - G4 (GC) (7.41 ± 1.65µmol/ml - q = 1.615 p > 0.05). Os voluntários do G4 (GC) e os do G3 (EHE/ELGE/AI) evidenciaram de forma significante maiores níveis de produção de ON pelos MS...

Mitochondrial reactive oxygen species regulate spatial profile of proinflammatory responses in lung venular capillaries.

Cytokine-induced lung expression of the endothelial cell (EC) leukocyte receptor P-selectin initiates leukocyte rolling. To understand the early EC signaling that induces the expression, we conducted real-time digital imaging studies in lung venular capillaries. To compare receptor- vs nonreceptor-mediated effects, we infused capillaries with respectively, TNF-alpha and arachidonate. At concentrations adjusted to give equipotent increases in the cytosolic Ca(2+), both agents increased reactive oxygen species (ROS) production and EC P-selectin expression. Blocking the cytosolic Ca(2+) increases abolished ROS production; blocking ROS production abrogated P-selectin expression. TNF-alpha, but not arachidonate, released Ca(2+) from endoplasmic stores and increased mitochondrial Ca(2+). Furthermore, Ca(2+) depletion abrogated TNF-alpha responses partially, but arachidonate responses completely. These differences in Ca(2+) mobilization by TNF-alpha and arachidonate were reflected in spatial patterning in the capillary in that the TNF-alpha effects were localized at branch points, while the arachidonate effects were nonlocalized and extensive. Furthermore, mitochondrial blockers inhibited the TNF-alpha- but not the arachidonate-induced responses. These findings indicate that the different modes of Ca(2+) mobilization determined the spatial patterning of the proinflammatory response in lung capillaries. Responses to TNF-alpha revealed that EC mitochondria regulate the proinflammatory process by generating ROS that activate P-selectin expression.

[Regulation of innate immunity during xenogenic changes in blood circulation]. / Rehuliatsia pryrodnoho imunitetu pry ksenohennykh porushenniakh krovobihy.

Calcium-dependent innate immune response with participation of the superfamily of immunoglobulins to several intra- and extracorporal xenobiotics were studied at 216 recipients during synthetic cardiac valves implantation or veins transplantation in coronary arteries. It was shown that immediate immune response to xenobiotics was manifested by generation of the antitissue anodical autoprecipitin with specificity to the surface cell membrane component. This reaction initiated and regulated the subsequent dynamics of the two different fibrinogen autoimmune complexes formation, resulting in development of the immunogenic damages of blood circulation. Correction of these rapid innate immune responses is important for prevention and normalisation of the xenogenic damages of blood circulation during trans- and implantation on the heart impaired with endocarditis or aterosclerosis.

Avaliacao de acesso vascular em hemodialise: um estudo multicentrico / Vascular access in hemodialysis: multicentric study

O objetivo do estudo foi a avaliacao de acesso vascular(AV) temporario e definitivo,em 11 centros brasileiros.As clinicas responderam a um questionario que procurou avaliar desde a realizacao a utilizacao e as complicacoes referentes ao AV.Verificou-se que 82 por cento nao possui um protocolo de acompanhamento de funcionamento e das complicacoes do AV.A complicacao mais relatada foi a trombose da fistula(80 por cento dos casos.O tempo medio de maturacao da fistula foi de 5 semanas(pmaior0,05).O local mais utilizado de acesso temporario foi a veia subclavia direita(73 por cento dos casos)Em 60 por cento dos centros mais de 30 por cento dos pacientes iniciam hemodialise com cateteres.O acompanhamento sistematizado(protocolo)mudanca no local de puncao(acessos temporarios),realizacao mais precoce de fistuls no periodo pre-dialitico,entre outras medidas,sao necessarias para uma melhor utilizacao do AV

Mast cells are augmented in deep vein thrombosis and express a profibrinolytic phenotype.

A number of recent data suggest that mast cells (MC) and their products are involved in the pathophysiology of thrombosis. In the current study, we have evaluated the number, distribution, and phenotype of MC in patients with deep vein thrombosis of the lower limb (DVT) (n = 15). Contralateral nonthrombosed limb veins served as control (CO). MC were examined by Giemsa staining and by immunohistochemistry using antibodies against tryptase, chymase, tissue-type plasminogen activator (tPA), urokinase (uPA), urokinase receptor (uPAR), and plasminogen activator inhibitors (PAI-1, PAI-2). We found an increase in the number of tryptase-positive MC in DVT compared with CO (DVT: 9.1+/-1.0 v CO: 4.7+/-0.6 MC/mm2, P < .05). Most of these MC appeared to accumulate in the adventitia of the thrombosed veins, in vicinity of the vasa vasorum. In both DVT and CO, MC reacted with monoclonal antibodies to c-kit, tryptase, and chymase. MC also stained positive for tPA and urokinase receptor, but did not express detectable PAI-1 or PAI-2. As compared with CO, a decreased proportion of MC in DVT was found to stain positive for chymase and tPA. Together, our results show that MC increase in number in DVT and express a profibrinolytic phenotype. We hypothesize that MC and MC-derived profibrinolytic molecules play a role in the pathophysiology of DVT.

[The humoral reactions of bioincompatibility in the early period after the heterotopic autograft of veins into the coronary bed and the implantation of synthetic heart valves]. / Humoral'ni reaktsiï bionesumisnosti u rann'omu periodi pislia heterotopichnoi autotransplantatsiï ven u koronarne ruslo ta implantatsiï syntetychnykh klapaniv sertsia.

Humoral manifestations of bioincompatibility were studied at early stages (during several hours and days) after operations using non-peculiar to heart trans- and implants: aortocoronary bypass at 102 patients with coronarosclerosis and implantation of artificial cardiac valves at 145 patients with endocarditis. In the various postoperation stages the formation of the structurally and functionally different types of the nonclonal specific autoprecipitins to autological membranocellular components was revealed at recipients by methods of double immunodiffusion and immunoelectrophoresis. These autoprecipitins such as: early, activated and tardly, synthesized under effect of alien agent--may be useful as diagnostic and prognostic indicators of bioincompatibility and its clinical consequences at the earliest period after cardiac operations using trans- and implants.

Epithelial- and endothelial-cell specificity of renal graft infiltrating T cells.

Previously, we have shown that rejecting renal allografts are infiltrated by tissue-specific T cells that in vitro kill proximal tubular epithelial cells (PTEC), while donor-derived splenocytes are not affected. In the current unique study we assessed the reactivity of graft-infiltrating T cells (GIC) for three different donor-derived cell types. Cytotoxicity of GIC was tested against PTEC, as well as donor-derived gonadal vein endothelial cells (GOVEC) and splenocytes. T cells lysed PTEC, GOVEC and splenocytes expressing a mismatched donor HLA antigen, HLA-A29(19). Interestingly, PTEC and GOVEC, not splenocytes, expressing none of the donor HLA antigens were also killed. T cell clones, obtained by limiting dilution cloning of the GIC line, could be divided into different categories: clones recognizing both PTEC and GOVEC expressing the mismatched HLA-A29(19), clones recognizing either PTEC or GOVEC expressing the mismatched HLA-A29(19) and also clones specifically recognizing PTEC or GOVEC independent of donor HLA antigen expression. In conclusion, T cell clones with specificities for either epithelial or endothelial cells exist, leaving a role for tissue-specific antigens in allograft rejection.