Gallic acid triphenylphosphonium derivatives TPP+-C10 and TPP+-C12 inhibit mitochondrial function in Candida albicans exerting antifungal and antibiofilm effects

AIMS

To evaluate the antifungal and antibiofilm activity of gallic acid derivatives TPP+-C10 and TPP+-C12 and their effects on mitochondrial function on two Candida albicans reference strains (ATCC 90029 and ATCC 10231).

METHODS AND RESULTS

First, we determined minimal inhibitory concentration (MIC) using a microdilution assay. Both compounds exerted antifungal effects, and their MICs ranged from 3.9 to 13 µM, with no statistically significant differences between them (P > 0.05, t-test). These concentrations served as references for following assays. Subsequently, we measured oxygen consumption with a Clark electrode. Our observations revealed that both drugs inhibited oxygen consumption in both strains with TPP+-C12 exerting a more pronounced inhibitory effect. We then employed flow cytometry with TMRE as a probe to assess mitochondrial membrane potential. For each strain assayed, the compounds induced a decay in transmembrane potential by 75%-90% compared to the control condition (P < 0.05, ANOVA). Then, we measured ATP levels using a commercial kit. TPP+-C12 showed a 50% decrease of ATP content (P < 0.05 ANOVA), while TPP+-C10 exhibited a less pronounced effect. Finally, we assessed the antibiofilm effect using the MTT reduction assay. Both compounds were effective, but TPP+-C12 displayed a greater potency, requiring a lower concentration to inhibit 50% of biofilms viability (P < 0.05, t-test).

CONCLUSIONS

Derivatives of gallic acid linked to a TPP+ group exert antifungal and antibiofilm activity through impairment of mitochondrial function in C. albicans.

Interferon-β decreases LPS-induced neutrophil recruitment to cardiac fibroblasts

Introduction: Cardiac fibroblasts (CF) are crucial cells in damaged heart tissues, expressing TLR4, IFN-receptor and responding to lipopolysaccharide (LPS) and interferon-β (IFN-β) respectively. While CF interact with immune cells; however, their relationship with neutrophils remains understudied. Additionally, theimpact of LPS and IFN-β on CF-neutrophil interaction is poorly understood. Methods: Isolated CF from adult rats were treated with LPS, with or without IFN-β. This study examined IL-8 secretion, ICAM-1 and VCAM-1 expression, and neutrophil recruitment, as well as their effects on MMPs activity. Results: LPS triggered increased IL-8 expression and secretion, along with elevated ICAM-1 and VCAM-1 expression, all of which were blocked by TAK-242. Pre-treatment with IFN-β countered these LPS effects. LPS treated CF showed higher neutrophil recruitment (migration and adhesion) compared to unstimulated CF, an effect prevented by IFN-β. Ruxolitinib blocked these IFN-β anti-inflammatory effects, implicating JAK signaling. Analysis of culture medium zymograms from CF alone, and CF-neutrophils interaction, revealed that MMP2 was mainly originated from CF, while MMP9 could come from neutrophils. LPS and IFN-β boosted MMP2 secretion by CF. MMP9 activity in CF was low, and LPS or IFN-β had no significant impact. Pre-treating CF with LPS, IFN-β, or both before co-culture with neutrophils increased MMP2. Neutrophil co-culture increased MMP9 activity, with IFN-β pre-treatment reducing MMP9 compared to unstimulated CF. Conclusion: In CF, LPS induces the secretion of IL-8 favoring neutrophils recruitment and these effects were blocked by IFN-. The results highlight that CF-neutrophil interaction appears to influence the extracellular matrix through MMPs activity modulation.

SGK1 is necessary to FoxO3a negative regulation, oxidative stress and cardiac fibroblast activation induced by TGF-β1

Cardiac fibroblasts (CFs) activation is a common response to most pathological conditions affecting the heart, characterized by increased cellular secretory capacity and increased expression of fibrotic markers, such as collagen I and smooth muscle actin type alpha (α-SMA). Fibrotic activation of CFs induces the increase in tissue protein content, with the consequent tissue stiffness, diastolic dysfunction, and heart failure. Therefore, the search for new mechanisms of CFs activation is important to find novel treatments for cardiac diseases characterized by fibrosis. In this regard, TGF-β1, a cytokine with proinflammatory and fibrotic properties, is crucial in the CFs activation and the development of fibrotic diseases, whereas its molecular targets are not completely known. Serum and glucocorticoid-regulated kinase (SGK1) is a protein involved in various pathophysiological phenomena, especially cardiac and renal diseases that curse with fibrosis. Additionally, SGK1 phosphorylates and regulates the activity and expression of several targets, highlighting FoxO3a for its role in the regulation of oxidative stress and CFs activation induced by TGF-β1. However, the regulation of SGK1 by TGF-β1 and its role in CFs activation have not been studied. In this work, we evaluate the role of SGK1 in CFs isolated from neonatal Sprague-Dawley rats. The participation of SGK1 in the fibrotic activation of CFs induced by TGF-β1 was analyzed, using an inhibitor or siRNA of SGK1. In addition, the role of SGK1 on the regulation of FoxO3a and oxidative stress induced by TGF-β1 was analyzed. Our results indicate that TGF-β1 increased both the activity and expression of SGK1 in CFs, requiring the activation of MAPKs, ERK1/2, p38 and JNK, while inhibition and silencing of SGK1 prevented TGF-β1-induced fibrotic activation of CFs. In addition, SGK1 inhibition prevented FoxO3a inactivation and expression reduction, catalase and SOD2 expression decrease, and the increase of oxidative stress induced by TGF-β1. Taken together, our results position SGK1 as an important regulator of CFs activation driven by TGF-β1, at least in part, through the regulation of FoxO3a and oxidative stress.

Lipoxin A4 prevents high glucose-induced inflammatory response in cardiac fibroblast through FOXO1 inhibition

Cardiac cells respond to various pathophysiological stimuli, synthesizing inflammatory molecules that allow tissue repair and proper functioning of the heart; however, perpetuation of the inflammatory response can lead to cardiac fibrosis and heart dysfunction. High concentration of glucose (HG) induces an inflammatory and fibrotic response in the heart. Cardiac fibroblasts (CFs) are resident cells of the heart that respond to deleterious stimuli, increasing the synthesis and secretion of both fibrotic and proinflammatory molecules. The molecular mechanisms that regulate inflammation in CFs are unknown, thus, it is important to find new targets that allow improving treatments for HG-induced cardiac dysfunction. NFκB is the master regulator of inflammation, while FoxO1 is a new participant in the inflammatory response, including inflammation induced by HG; however, its role in the inflammatory response of CFs is unknown. The inflammation resolution is essential for an effective tissue repair and recovery of the organ function. Lipoxin A4 (LXA4) is an anti-inflammatory agent with cytoprotective effects, while its cardioprotective effects have not been fully studied. Thus, in this study, we analyze the role of p65/NFκB, and FoxO1 in CFs inflammation induced by HG, evaluating the anti-inflammatory properties of LXA4. Our results demonstrated that HG induces the inflammatory response in CFs, using an in vitro and ex vivo model, while FoxO1 inhibition and silencing prevented HG effects. Additionally, LXA4 inhibited the activation of FoxO1 and p65/NFκB, and inflammation of CFs induced by HG. Therefore, our results suggest that FoxO1 and LXA4 could be novel drug targets for the treatment of HG-induced inflammatory and fibrotic disorders in the heart.

Statins change the cytokine profile in Trypanosoma cruzi-infected U937 macrophages and murine cardiac tissue through Rho-associated kinases inhibition

Introduction

Chronic Chagasic cardiomyopathy (CCC), caused by the protozoan Trypanosoma cruzi, is the most severe manifestation of Chagas disease.CCC is characterized by cardiac inflammation and fibrosis caused by a persistent inflammatory response. Following infection, macrophages secrete inflammatory mediators such as IL-1β, IL-6, and TNF-α to control parasitemia. Although this response contains parasite infection, it causes damage to the heart tissue. Thus, the use of immunomodulators is a rational alternative to CCC. Rho-associated kinase (ROCK) 1 and 2 are RhoA-activated serine/threonine kinases that regulate the actomyosin cytoskeleton. Both ROCKs have been implicated in the polarization of macrophages towards an M1 (pro-inflammatory) phenotype. Statins are FDA-approved lipid-lowering drugs that reduce RhoA signaling by inhibiting geranylgeranyl pyrophosphate (GGPP) synthesis. This work aims to identify the effect of statins on U937 macrophage polarization and cardiac tissue inflammation and its relationship with ROCK activity during T. cruzi infection.

Methods

PMA-induced, wild-type, GFP-, CA-ROCK1- and CA-ROCK2-expressing U937 macrophages were incubated with atorvastatin, or the inhibitors Y-27632, JSH-23, TAK-242, or C3 exoenzyme incubated with or without T. cruzi trypomastigotes for 30 min to evaluate the activity of ROCK and the M1 and M2 cytokine expression and secretion profiling. Also, ROCK activity was determined in T. cruzi-infected, BALB/c mice hearts.

Results

In this study, we demonstrate for the first time in macrophages that incubation with T. cruzi leads to ROCK activation via the TLR4 pathway, which triggers NF-κB activation. Inhibition of ROCKs by Y-27632 prevents NF-κB activation and the expression and secretion of M1 markers, as does treatment with atorvastatin. Furthermore, we show that the effect of atorvastatin on the NF-kB pathway and cytokine secretion is mediated by ROCK. Finally, statin treatment decreased ROCK activation and expression, and the pro-inflammatory cytokine production, promoting anti-inflammatory cytokine expression in chronic chagasic mice hearts.

Conclusion

These results suggest that the statin modulation of the inflammatory response due to ROCK inhibition is a potential pharmacological strategy to prevent cardiac inflammation in CCC.

Angiotensin II Triggers NLRP3 Inflammasome Activation by a Ca2+ Signaling-Dependent Pathway in Rat Cardiac Fibroblast Ang-II by a Ca2+-Dependent Mechanism Triggers NLRP3 Inflammasome in CF

Angiotensin II (Ang-II) is a widely studied hypertensive, profibrotic, and pro-inflammatory peptide. In the heart, cardiac fibroblasts (CF) express type 1 angiotensin II receptors (AT1R), Toll-like receptor-4 (TLR4), and the NLRP3 inflammasome complex, which play important roles in pro-inflammatory processes. When activated, the NLRP3 inflammasome triggers proteolytic cleavage of pro-IL-1, resulting in its activation. However, in CF the mechanism by which Ang-II assembles and activates the NLRP3 inflammasome remains not fully known. To elucidate this important point, we stimulated TLR4 receptors in CF and evaluated the signaling pathways by which Ang-II triggers the assembly and activity. In cultured rat CF, pro-IL-1β levels, NLRP3, ASC, and caspase-1 expression levels were determined by Western blot. NLRP3 inflammasome complex assembly was analyzed by immunocytochemistry, whereas by ELISA, we analyzed NLRP3 inflammasome activity and [Formula: see text] release. In CF, Ang-II triggered NLRP3 inflammasome assembly and caspase-1 activity; and in LPS-pretreated CF, Ang-II also triggered [Formula: see text] secretion. These effects were blocked by losartan (AT1R antagonist), U73221 (PLC inhibitor), 2-APB (IP3R antagonist), and BAPTA-AM (Ca²⁺ chelator) indicating that the AT1R/PLC/IP3R/Ca²⁺ pathway is involved. Finally, bafilomycin A1 prevented Ang-II-induced [Formula: see text] secretion, indicating that a non-classical protein secretion mechanism is involved. These findings suggest that in CF, Ang-II by a Ca²⁺-dependent mechanism triggers NLRP3 inflammasome assembly and activation leading to [Formula: see text] secretion through a non-conventional protein secretion mechanism.

Communication Between Cardiomyocytes and Fibroblasts During Cardiac Ischemia/Reperfusion and Remodeling: Roles of TGF-β, CTGF, the Renin Angiotensin Axis, and Non-coding RNA Molecules

Communication between cells is a foundational concept for understanding the physiology and pathology of biological systems. Paracrine/autocrine signaling, direct cell-to-cell interplay, and extracellular matrix interactions are three types of cell communication that regulate responses to different stimuli. In the heart, cardiomyocytes, fibroblasts, and endothelial cells interact to form the cardiac tissue. Under pathological conditions, such as myocardial infarction, humoral factors released by these cells may induce tissue damage or protection, depending on the type and concentration of molecules secreted. Cardiac remodeling is also mediated by the factors secreted by cardiomyocytes and fibroblasts that are involved in the extensive reciprocal interactions between these cells. Identifying the molecules and cellular signal pathways implicated in these processes will be crucial for creating effective tissue-preserving treatments during or after reperfusion. Numerous therapies to protect cardiac tissue from reperfusion-induced injury have been explored, and ample pre-clinical research has attempted to identify drugs or techniques to mitigate cardiac damage. However, despite great success in animal models, it has not been possible to completely translate these cardioprotective effects to human applications. This review provides a current summary of the principal molecules, pathways, and mechanisms underlying cardiomyocyte and cardiac fibroblast crosstalk during ischemia/reperfusion injury. We also discuss pre-clinical molecules proposed as treatments for myocardial infarction and provide a clinical perspective on these potential therapeutic agents.

Resolvin-D1 attenuation of angiotensin II-induced cardiac inflammation in mice is associated with prevention of cardiac remodeling and hypertension

AIMS

Despite the broad pharmacological arsenal to treat hypertension, chronic patients may develop irreversible cardiac remodeling and fibrosis. Angiotensin II, the main peptide responsible for the Renin-Angiotensin-Aldosterone-System, has been closely linked to cardiac remodeling, hypertrophy, fibrosis, and hypertension, and some of these effects are induced by inflammatory mediators. Resolvin-D1 (RvD1) elicits potent anti-inflammatory and pro-resolving effects in various pathological models. In this study, we aimed to examine whether RvD1 ameliorates cardiac remodeling and hypertension triggered by angiotensin II.

METHODS AND RESULTS

Alzet® osmotic mini-pumps filled with angiotensin II (1.5 mg/kg/day) were implanted in male C57BL/6 J mice for 7 or 14 days. RvD1 (3 μg/kg/day, i.p) was administered one day after the surgery and during the complete infusion period. Blood pressure and myocardial functional parameters were assessed by echocardiography. At the end of the experimental procedure, blood and heart tissue were harvested, and plasma and histological parameters were studied. After 7 and 14 days, RvD1 reduced the increase of neutrophil and macrophage infiltration triggered by angiotensin II, and also reduced ICAM-1 and VCAM-1 expression levels. RvD1 also reduced cytokine plasma levels (IL-1β, TNF-α, IL-6, KC, MCP-1), cardiac hypertrophy, interstitial and perivascular fibrosis, and hypertension.

CONCLUSIONS

This study unveils novel cardioprotective effects of RvD1 in angiotensin II-induced hypertension and cardiac remodeling by attenuating inflammation and provides insights into a potential clinical application.

FoxO1 is required for high glucose-dependent cardiac fibroblasts into myofibroblast phenoconversion

In the normal heart, cardiac fibroblasts (CFs) maintain extracellular matrix (ECM) homeostasis, whereas in pathological conditions, such as diabetes mellitus (DM), CFs converse into cardiac myofibroblasts (CMFs) and this CFs phenoconversion increase the synthesis and secretion of ECM proteins, promoting cardiac fibrosis and heart dysfunction. High glucose (HG) conditions increase TGF-β1 expression and FoxO1 activity, whereas FoxO1 is crucial to CFs phenoconversion induced by TGF-β1. In addition, FoxO1 increases CTGF expression, whereas CTGF plays an active role in the fibrotic process induced by hyperglycemia. However, the role of FoxO1 and CTGF in CFs phenoconversion induced by HG is not clear. In this study, we investigated the effects of FoxO1 pharmacological inhibition on CFs phenoconversion in both in vitro and ex vivo models of DM. Our results demonstrate that HG induces CFs phenoconversion and FoxO1 activation. Moreover, AS1842856, a pharmacological inhibitor of FoxO1 activity, prevents CFs phenoconversion and CTGF expression increase induced by HG, whereas these results were corroborated by FoxO1 silencing. Additionally, K252a, a pharmacological blocker of CTGF receptor, prevents HG-induced CFs phenoconversion, which was corroborated with CTGF expression knockdown. Furthermore, through CFs isolation from heart of diabetic rats, we showed that hyperglycemia induces FoxO1 activation, the increase of CTGF expression and CFs phenoconversion, whereas the FoxO1 activity inhibition reverses the effects induced by hyperglycemia on CFs. Altogether, our results demonstrate that FoxO1 and CTGF are necessary for CFs phenoconversion induced by HG and suggest that both proteins are likely to become a potential targeted drug for fibrotic response induced by hyperglycemic conditions.

TGF-β1 decreases CHOP expression and prevents cardiac fibroblast apoptosis induced by endoplasmic reticulum stress

Transforming growth factor-beta 1 (TGF-β1) is a cytokine with marked pro-fibrotic action on cardiac fibroblasts (CF). TGF-β1 induces CF-to-cardiac myofibroblast (CMF) differentiation, defined by an increase in α-smooth muscle cells (α-SMA), collagen secretion and it has a cytoprotective effect against stimuli that induce apoptosis. In the Endoplasmic Reticulum (ER) lumen, misfolded protein accumulation triggers ER stress and induces apoptosis, and this process plays a critical role in cell death mediated by Ischemia/Reperfusion (I/R) injury and by ER stress inducers, such as Tunicamycin (Tn). Here, we studied the regulation of CHOP, a proapoptotic ER-stress-related transcription factor in CF under simulated I/R (sI/R) or exposed to Tn. Even though TGF-β1 has been shown to participate in ER stress, its regulatory effect on CF apoptosis and ER stress-induced by sI/R or TN has not been evaluated yet. CF from neonatal rats were exposed to sI/R, and cell death was evaluated by cell count and apoptosis by flow cytometry. ER stress was assessed by western blot against CHOP. Our results evidenced that sI/R (8/24) h or Tn triggers CF apoptosis and an increase in CHOP protein levels. TGF-β1 pre-treatment partially prevented apoptosis induced by sI/R or Tn. Furthermore, TGF-β1 pre-treatment completely prevented CHOP increase by sI/R or Tn. Additionally, we found a decrease in α-SMA expression induced by sI/R and in collagen secretion induced by Tn, which were not prevented by TGF-β1 treatment. In conclusion, TGF-β1 partially protects CF apoptosis induced by sI/R or Tn, through a mechanism that would involve ER stress.

Resolvin D1 and E1 promote resolution of inflammation in rat cardiac fibroblast in vitro

Cardiac fibroblasts (CFs) have a key role in the inflammatory response after cardiac injury and are necessary for wound healing. Resolvins are potent agonists that control the duration and magnitude of inflammation. They decrease mediators of pro-inflammatory expression, reduce neutrophil migration to inflammation sites, promote the removal of microbes and apoptotic cells, and reduce exudate. However, whether resolvins can prevent pro-inflammatory-dependent effects in CFs is unknown. Thus, the present work was addressed to study whether resolvin D1 and E1 (RvD1 and RvE1) can prevent pro-inflammatory effects on CFs after lipopolysaccharide (LPS) challenge. For this, CFs were stimulated with LPS, in the presence or absence of RvD1 or RvE1, to analyze its effects on intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), monocyte adhesion and the cytokine levels of tumor necrosis factor alpha (TNF-α), interleukin-6(IL-6), interleukin-1beta (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and interleukin-10 (IL-10). Our results showed that CFs are expressing ALX/FPR2 and ChemR23, RvD1 and RvE1 receptors, respectively. RvD1 and RvE1 prevent the increase of ICAM-1 and VCAM-1 protein levels and the adhesion of spleen mononuclear cells to CFs induced by LPS. Finally, RvD1, but not RvE1, prevents the LPS-induced increase of IL-6, MCP-1, TNF-α, and IL-10. In conclusion, our findings provide evidence that in CFs, RvD1 and RvE1 might actively participate in the prevention of inflammatory response triggered by LPS.

In cardiac fibroblasts, interferon-beta attenuates differentiation, collagen synthesis, and TGF-β1-induced collagen gel contraction

Cardiac fibroblasts (CF) play a key role in the homeostasis of the extracellular matrix in cardiac tissue and are newly recognized as inflammatory supporter cells. Besides, CF-to-Cardiac myofibroblast differentiation is commanded by TGF-b, through SMAD signaling pathways, and these last cells are strongly implicated in cardiac fibrosis. In the heart IFN-β is produced by CF; however, the role of IFN-β, STAT proteins, and STAT-homo or heterodimers in the regulation of CF function with or without a fibrotic environment is unknown. CF were isolated from hearts of adult rats, and by western blot analysis we studied STAT1, STAT2, and STAT3 phosphorylation and through specific siRNA against these proteins we analyzed their role in CF functions such as differentiation (α-SMA expression); and pro-collagen type-I synthesis and secretion expression levels; collagen gels contraction and CF migration. In cultured adult rats CF, IFN-β increases phosphorylation of STAT1, STAT2, and STAT3. Both STAT1 and STAT2 were involved in decreasing α-SMA and CF migration induced by TGF-β1. Also, IFN-β through STAT1 regulated pro-collagen type-I protein expression levels, and collagen gels contraction induced by TGF-β1. STAT3 was not involved in any effects of IFN-β studied. In conclusion, IFN-β through STAT1 and STAT2 shows antifibrotic effects on CF TGF-β1-treated, whereas STAT3 did not participate in such effect.

Role of FoxO3a as a negative regulator of the cardiac myofibroblast conversion induced by TGF-β1

Cardiac fibroblasts (CFs) are necessary to maintain extracellular matrix (ECM) homeostasis in the heart. Normally, CFs are quiescent and secrete small amounts of ECM components, whereas, in pathological conditions, they differentiate into more active cells called cardiac myofibroblasts (CMF). CMF conversion is characteristic of cardiac fibrotic diseases, such as heart failure and diabetic cardiomyopathy. TGF-β1 is a key protein involved in CMF conversion. SMADs are nuclear factor proteins activated by TGF-β1 that need other proteins, such as forkhead box type O (FoxO) family members, to promote CMF conversion. FoxO1, a member of this family protein, is necessary for TGF-β1-induced CMF conversion, whereas the role of FoxO3a, another FoxO family member, is unknown. FoxO3a plays an important role in many fibrotic processes in the kidney and lung. However, the participation of FoxO3a in the conversion of CFs into CMF is not clear. In this paper, we demonstrate that TGF-β1 decreases the activation and expression of FoxO3a in CFs. FoxO3a regulation by TGF-β1 requires activated SMAD3, ERK1/2 and Akt. Furthermore, we show that FoxO1 is crucial in the FoxO3a regulation induced by TGF-β1, as shown by overexpressed FoxO1 enhancing and silenced FoxO1 suppressing the effects of TGF-β1 on FoxO3a. Finally, the regulation of TGF-β1-induced CMF conversion was enhanced by FoxO3a silencing and suppressed by inhibited FoxO3a degradation. Considering these collective findings, we suggest that FoxO3a acts as a negative regulator of the CMF conversion that is induced by TGF-β1.

IFN-β Plays Both Pro- and Anti-inflammatory Roles in the Rat Cardiac Fibroblast Through Differential STAT Protein Activation

Cardiac fibroblasts (CFs) contribute to theinflammatory response to tissue damage, secreting both pro- and anti-inflammatory cytokines and chemokines. Interferon beta (IFN-β) induces the phosphorylation of signal transducer and activator of transcription (STAT) proteins through the activation of its own receptor, modulating the secretion of cytokines and chemokines which regulate inflammation. However, the role of IFN-β and STAT proteins in modulating the inflammatory response of CF remains unknown. CF were isolated from adult male rats and subsequently stimulated with IFN-β to evaluate the participation of STAT proteins in secreting chemokines, cytokines, cell adhesion proteins expression and in their capacity to recruit neutrophils. In addition, in CF in which the TRL4 receptor was pre-activated, the effect of INF-β on the aforementioned responses was also evaluated. Cardiac fibroblasts stimulation with IFN-β showed an increase in STAT1, STAT2, and STAT3 phosphorylation. IFN-β stimulation through STAT1 activation increased proinflammatory chemokines MCP-1 and IP-10 secretion, whereas IFN-β induced activation of STAT3 increased cytokine secretion of anti-inflammatory IL-10. Moreover, in TLR4-activated CF, IFN-β through STAT2 and/or STAT3, produced an anti-inflammatory effect, reducing pro-IL-1β, TNF-α, IL-6, MCP-1, and IP-10 secretion; and decreasing neutrophil recruitment by decreasing ICAM-1 and VCAM-1 expression. Altogether, our results indicate that IFN-β exerts both pro-inflammatory and anti-inflammatory effects in non-stimulated CF, through differential activation of STAT proteins. When CF were previously treated with an inflammatory agent such as TLR-4 activation, IFN-β effects were predominantly anti-inflammatory.

Elastin degradation products in acute lung injury induced by gastric contents aspiration

Background

Gastric contents aspiration is a high-risk condition for acute lung injury (ALI). Consequences range from subclinical pneumonitis to respiratory failure, depending on the volume of aspirate. A large increment in inflammatory cells, an important source of elastase, potentially capable of damaging lung tissue, has been described in experimental models of aspiration. We hypothesized that in early stages of aspiration-induced ALI, there is proteolytic degradation of elastin, preceding collagen deposition. Our aim was to evaluate whether after a single orotracheal instillation of gastric fluid, there is evidence of elastin degradation.

Methods

Anesthesized Sprague-Dawley rats received a single orotracheal instillation of gastric fluid and were euthanized 4, 12 and 24 h and at day 4 after instillation (n = 6/group). We used immunodetection of soluble elastin in lung tissue and BALF and correlated BALF levels of elastin degradation products with markers of ALI. We investigated possible factors involved in elastin degradation and evaluated whether a similar pattern of elastin degradation can be found in BALF samples of patients with interstitial lung diseases known to have aspirated. Non-parametric ANOVA (Kruskall-Wallis) and linear regression analysis were used.

Results

We found evidence of early proteolytic degradation of lung elastin. Elastin degradation products are detected both in lung tissue and BALF in the first 24 h and are significantly reduced at day 4. They correlate significantly with ALI markers, particularly PMN cell count, are independent of acidity and have a similar molecular weight as those obtained using pancreatic elastase. Evaluation of BALF from patients revealed the presence of elastin degradation products not present in controls that are similar to those found in BALF of rats treated with gastric fluid.

Conclusions

A single instillation of gastric fluid into the lungs induces early proteolytic degradation of elastin, in relation to the magnitude of alveolar-capillary barrier derangement. PMN-derived proteases released during ALI are mostly responsible for this damage. BALF from patients showed elastin degradation products similar to those found in rats treated with gastric fluid. Long-lasting effects on lung elastic properties could be expected under conditions of repeated instillations of gastric fluid in experimental animals or repeated aspiration events in humans.

Lipopolysaccharide Activates Toll-Like Receptor 4 and Prevents Cardiac Fibroblast-to-Myofibroblast Differentiation

Bacterial lipopolysaccharide (LPS) is a known ligand of Toll-like receptor 4 (TLR4) which is expressed in cardiac fibroblasts (CF). Differentiation of CF to cardiac myofibroblasts (CMF) is induced by transforming growth factor-β1 (TGF-β1), increasing alpha-smooth muscle actin (α-SMA) expression. In endothelial cells, an antagonist effect between LPS-induced signaling and canonical TGF-β1 signaling was described; however, it has not been studied whether in CF and CMF the expression of α-SMA induced by TGF-β1 is antagonized by LPS and the mechanism involved. In adult rat CF and CMF, α-SMA, ERK1/2, Akt, NF-κβ, Smad3, and Smad7 protein levels were determined by western blot, TGF-β isoforms by ELISA, and α-SMA stress fibers by immunocytochemistry. CF and CMF secrete the three TGF-β isoforms, and the secretion levels of TGF-β2 was affected by LPS treatment. In CF, LPS treatment decreased the protein levels of α-SMA, and this effect was prevented by TAK-242 (TLR4 inhibitor) and LY294002 (Akt inhibitor), but not by BAY 11-7082 (NF-κβ inhibitor) and PD98059 (ERK1/2 inhibitor). TGF-β1 increased α-SMA protein levels in CF, and LPS prevented partially this effect. In addition, in CMF α-SMA protein levels were decreased by LPS treatment, which was abolished by TAK-242. Finally, in CF LPS decreased the p-Smad3 phosphorylation and increased the Smad7 protein levels. LPS treatment prevents the CF-to-CMF differentiation and reverses the CMF phenotype induced by TGF-β1, through decreasing p-Smad3 and increasing Smad7 protein levels.

Expression and function of TLR4- induced B1R bradykinin receptor on cardiac fibroblasts

Cardiac fibroblasts (CF) are key cells for maintaining extracellular matrix (ECM) protein homeostasis in the heart, and for cardiac repair through CF-to-cardiac myofibroblast (CMF) differentiation. Additionally, CF play an important role in the inflammatory process after cardiac injury, and they express Toll like receptor 4 (TLR4), B1 and B2 bradykinin receptors (B1R and B2R) which are important in the inflammatory response. B1R and B2R are induced by proinflammatory cytokines and their activation by bradykinin (BK: B2R agonist) or des-arg-kallidin (DAKD: B1R agonist), induces NO and PGI2 production which is key for reducing collagen I levels. However, whether TLR4 activation regulates bradykinin receptor expression remains unknown. CF were isolated from human, neonatal rat and adult mouse heart. B1R mRNA expression was evaluated by qRT-PCR, whereas B1R, collagen, COX-2 and iNOS protein levels were evaluated by Western Blot. NO and PGI2 were evaluated by commercial kits. We report here that in CF, TLR4 activation increased B1R mRNA and protein levels, as well as COX-2 and iNOS levels. B1R mRNA levels were also induced by interleukin-1α via its cognate receptor IL-1R1. In LPS-pretreated CF the DAKD treatment induced higher responses with respect to those observed in non LPS-pretreated CF, increasing PGI2 secretion and NO production; and reducing collagen I protein levels in CF. In conclusion, no significant response to DAKD was observed (due to very low expression of B1R in CF) - but pre-activation of TLR4 in CF, conditions that significantly enhanced B1R expression, led to an additional response of DAKD.

Changes in the pattern of fibrosis in the rat lung with repetitive orotracheal instillations of gastric contents: evidence of persistent collagen accumulation

Recurrent aspiration of gastric contents has been associated with several interstitial lung diseases. Despite this association, the pathogenic role of aspiration in these diseases has been poorly studied and little is known about extracellular matrix (ECM) changes in animal models of repetitive events of aspiration. Our aim was to study the repair phase of lung injury induced by each of several instillations of gastric fluid in Sprague-Dawley rats to evaluate changes in ECM and their reversibility. Anesthetized animals received weekly orotracheal instillations of gastric fluid for 1, 2, 3, and 4 wk and were euthanized at day 7 after last instillation. For reversibility studies, another group received 7 weekly instillations and was euthanized at day 7 or 60 after last instillation. Biochemical and histological measurements were used to evaluate ECM changes. Lung hydroxyproline content increased progressively and hematoxylin and eosin, Masson's trichrome, and alpha-SMA stains showed that after a single instillation, intra-alveolar fibrosis predominated, whereas with repetitive instillations this fibrosis pattern became less prominent and interstitial fibrosis progressively became evident. Both type I and III collagen increased in intra-alveolar and interstitial fibrosis. Imbalance between matrix metalloproteinase-2 (MMP-2) activity and tissue inhibitor of metalloproteinase-2 (TIMP-2) expression was observed, favoring either collagen degradation or accumulation depending on the number of instillations. Caspase-3 activation was also dose dependent. ECM changes were partially reversible at long-term evaluation, since Masson bodies, granulomas, and foreign body giant cells disappeared, whereas interstitial collagen accumulated. In conclusion, repetitive lung instillations of gastric fluid induce progressive fibrotic changes in rat lung ECM that persist at long-term evaluation.

Acute lung injury by gastric fluid instillation: activation of myofibroblast apoptosis during injury resolution

BACKGROUND

Gastric contents aspiration in humans has variable consequences depending on the volume of aspirate, ranging from subclinical pneumonitis to respiratory failure with up to 70% mortality. Several experimental approaches have been used to study this condition. In a model of single orotracheal instillation of gastric fluid we have shown that severe acute lung injury evolves from a pattern of diffuse alveolar damage to one of organizing pneumonia (OP), that later resolves leaving normal lung architecture. Little is known about mechanisms of injury resolution after a single aspiration that could be dysregulated with repetitive aspirations. We hypothesized that, in a similar way to cutaneous wound healing, apoptosis may participate in lung injury resolution by reducing the number of myofibroblasts and by affecting the balance between proteases and antiproteases. Our aim was to study activation of apoptosis as well as MMP-2/TIMP-2 balance in the sub-acute phase (4-14 days) of gastric fluid-induced lung injury.

METHODS

Anesthesized Sprague-Dawley rats received a single orotracheal instillation of gastric fluid and were euthanized 4, 7 and 14 days later (n = 6/group). In lung tissue we studied caspase-3 activation and its location by double immunofluorescence for cleaved caspase-3 or TUNEL and alpha-SMA. MMP-2/TIMP-2 balance was studied by zymography and Western blot. BALF levels of TGF-β₁ were measured by ELISA.

RESULTS

An OP pattern with Masson bodies and granulomas was seen at days 4 and 7 that was no longer present at day 14. Cleaved caspase-3 increased at day 7 and was detected by immunofluorescence in Masson body-alpha-SMA-positive and -negative cells. TUNEL-positive cells at days 4 and 7 were located mainly in Masson bodies. Distribution of cleaved caspase-3 and TUNEL-positive cells at day 14 was similar to that in controls. At the peak of apoptosis (day 7), an imbalance between MMP-2 activity and TIMP-2 expression was produced by reduction in TIMP-2 expression.

CONCLUSIONS

Apoptosis is activated in Masson body-alpha-SMA-positive and -negative cells during the sub-acute phase of gastric fluid-induced lung injury. This mechanism likely contributes to OP resolution, by reducing myofibroblast number and new collagen production. In addition, pre-formed collagen degradation is favored by an associated MMP-2/TIMP-2 imbalance.

Cardiac fibroblast cytokine profiles induced by proinflammatory or profibrotic stimuli promote monocyte recruitment and modulate macrophage M1/M2 balance in vitro

Macrophage polarization plays an essential role in cardiac remodeling after injury, evolving from an initial accumulation of proinflammatory M1 macrophages to a greater balance of anti-inflammatory M2 macrophages. Whether cardiac fibroblasts themselves influence this process remains an intriguing question. In this work, we present evidence for a role of cardiac fibroblasts (CF) as regulators of macrophage recruitment and skewing. Adult rat CF, were treated with lipopolysaccharide (LPS) or TGF-β1, to evaluate ICAM-1 and VCAM-1 expression using Western blot and proinflammatory/profibrotic cytokine secretion using LUMINEX. We performed in vitro migration and adhesion assays of rat spleen monocytes to layers of TGF-β1- or LPS-pretreated CF. Finally, TGF-β1- or LPS-pretreated CF were co-cultured with monocyte, to evaluate their effects on macrophage polarization, using flow cytometry and cytokine secretion. There was a significant increase in monocyte adhesion to LPS- or TGF-β1-stimulated CF, associated with increased CF expression of ICAM-1 and VCAM-1. siRNA silencing of either ICAM-1 or VCAM-1 inhibited monocyte adhesion to LPS-pretreated CF; however, monocyte adhesion to TGF-β1-treated CF was dependent on only VCAM-1 expression. Pretreatment of CF with LPS or TGF-β1 increased monocyte migration to CF, and this effect was completely abolished with an MCP-1 antibody blockade. LPS-treated CF secreted elevated levels of TNF-α and MCP-1, and when co-cultured with monocyte, LPS-treated CF stimulated increased macrophage M1 polarization and secretion of proinflammatory cytokines (TNF-α, IL-12 and MCP-1). On the other hand, CF stimulated with TGF-β1 produced an anti-inflammatory cytokine profile (high IL-10 and IL-5, low TNF-α). When co-cultured with monocytes, the TGF-β1 stimulated fibroblasts skewed monocyte differentiation towards M2 macrophages accompanied by increased IL-10 and decreased IL-12 levels. Taken together, our results show for the first time that CF can recruit monocytes (via MCP-1-mediated chemotaxis and adhesion to ICAM-1/VCAM-1) and induce their differentiation to M1 or M2 macrophages (through the CF cytokine profile induced by proinflammatory or profibrotic stimuli).

Cardiac fibroblasts as sentinel cells in cardiac tissue: Receptors, signaling pathways and cellular functions

Cardiac fibroblasts (CF) not only modulate extracellular matrix (ECM) proteins homeostasis, but also respond to chemical and mechanical signals. CF express a variety of receptors through which they modulate the proliferation/cell death, autophagy, adhesion, migration, turnover of ECM, expression of cytokines, chemokines, growth factors and differentiation into cardiac myofibroblasts (CMF). Differentiation of CF to CMF involves changes in the expression levels of various receptors, as well as, changes in cell phenotype and their associated functions. CF and CMF express the β2-adrenergic receptor, and its stimulation activates PKA and EPAC proteins, which differentially modulate the CF and CMF functions mentioned above. CF and CMF also express different levels of Angiotensin II receptors, in particular, AT1R activation increases collagen synthesis and cell proliferation, but its overexpression activates apoptosis. CF and CMF express different levels of B1 and B2 kinin receptors, whose stimulation by their respective agonists activates common signaling transduction pathways that decrease the synthesis and secretion of collagen through nitric oxide and prostacyclin I2 secretion. Besides these classical functions, CF can also participate in the inflammatory response of cardiac repair, through the expression of receptors commonly associated to immune cells such as Toll like receptor 4, NLRP3 and interferon receptor. The activation by their respective agonists modulates the cellular functions already described and the release of cytokines and chemokines. Thus, CF and CMF act as sentinel cells responding to a plethora of stimulus, modifying their own behavior, and that of neighboring cells.

EPAC expression and function in cardiac fibroblasts and myofibroblasts

In the heart, cardiac fibroblasts (CF) and cardiac myofibroblasts (CMF) are the main cells responsible for wound healing after cardiac insult. Exchange protein activated by cAMP (EPAC) is a downstream effector of cAMP, and it has been not completely studied on CF. Moreover, in CMF, which are the main cells responsible for cardiac healing, EPAC expression and function are unknown. We evaluated in both CF and CMF the effect of transforming growth factor β1 (TGF-β1) on EPAC-1 expression. We also studied the EPAC involvement on collagen synthesis, adhesion, migration and collagen gel contraction.

METHOD

Rat neonatal CF and CMF were treated with TGF-β1 at different times and concentrations. EPAC-1 protein levels and Rap1 activation were measured by western blot and pull down assay respectively. EPAC cellular functions were determined by adhesion, migration and collagen gel contraction assay; and collagen expression was determined by western blot.

RESULTS

TGF-β1 through Smad and JNK significantly reduced EPAC-1 expression in CF, while in CMF this cytokine increased EPAC-1 expression through ERK1/2, JNK, p38, AKT and Smad3. EPAC activation was able to induce higher Rap1-GTP levels in CMF than in CF. EPAC and PKA, both cAMP effectors, promoted CF and CMF adhesion on fibronectin, as well as CF migration; however, this effect was not observed in CMF. EPAC but not PKA activation mediated collagen gel contraction in CF, while in CMF both PKA and EPAC mediated collagen gel contraction. Finally, the EPAC and PKA activation reduced collagen synthesis in CF and CMF.

CONCLUSION

TGF-β1 differentially regulates the expression of EPAC in CF and CMF; and EPAC regulates differentially CF and CMF functions associated with cardiac remodeling.

TGF-β1 prevents simulated ischemia/reperfusion-induced cardiac fibroblast apoptosis by activation of both canonical and non-canonical signaling pathways

Ischemia/reperfusion injury is a major cause of myocardial death. In the heart, cardiac fibroblasts play a critical role in healing post myocardial infarction. TGF-β1 has shown cardioprotective effects in cardiac damage; however, if TGF-β1 can prevent cardiac fibroblast death triggered by ischemia/reperfusion is unknown. Therefore, we test this hypothesis, and whether the canonical and/or non-canonical TGF-β1 signaling pathways are involved in this protective effect. Cultured rat cardiac fibroblasts were subjected to simulated ischemia/reperfusion. Cell viability was analyzed by trypan blue exclusion and propidium iodide by flow cytometry. The processing of procaspases 8, 9 and 3 to their active forms was assessed by Western blot, whereas subG1 population was evaluated by flow cytometry. Levels of total and phosphorylated forms of ERK1/2, Akt and Smad2/3 were determined by Western blot. The role of these signaling pathways on the protective effect of TGF-β1 was studied using specific chemical inhibitors. Simulated ischemia over 8h triggers a significant cardiac fibroblast death, which increased by reperfusion, with apoptosis actively involved. These effects were only prevented by the addition of TGF-β1 during reperfusion. TGF-β1 pretreatment increased the levels of phosphorylated forms of ERK1/2, Akt and Smad2/3. The inhibition of ERK1/2, Akt and Smad3 also blocked the preventive effects of TGF-β1 on cardiac fibroblast apoptosis induced by simulated ischemia/reperfusion. Overall, our data suggest that TGF-β1 prevents cardiac fibroblast apoptosis induced by simulated ischemia-reperfusion through the canonical (Smad3) and non canonical (ERK1/2 and Akt) signaling pathways.

Cardiac fibroblast death by ischemia/reperfusion is partially inhibited by IGF-1 through both PI3K/Akt and MEK-ERK pathways

Cardiac fibroblast (CF) death by ischemia/reperfusion (I/R) has major implications for cardiac wound healing. Although IGF-1 has well-known cytoprotective effects, no study has been done on CF subjected to simulated I/R. Simulated ischemia of neonate rat CF was performed in a free oxygen chamber in an ischemic medium; reperfusion was done in normal culture conditions. Cell viability was evaluated by trypan blue assay, and apoptosis by a FACS flow cytometer; p-ERK-1/2 and p-Akt levels were determined by western blot. We showed that simulated I/R triggers CF death by necrosis and apoptosis. IGF-1 partially inhibits I/R-induced apoptosis. PD98059 and LY294002 neutralize the preventive effects of IGF-1.

CONCLUSION

IGF-1 partially inhibits CF apoptosis induced by simulated I/R by PI3K/Akt- and MEK/ERK1/2-dependent signaling pathways.

Attenuation of endoplasmic reticulum stress using the chemical chaperone 4-phenylbutyric acid prevents cardiac fibrosis induced by isoproterenol

Increasing evidence indicates that endoplasmic reticulum (ER) stress is involved in various diseases. In the human heart, ischemia/reperfusion has been correlated to ER stress, and several markers of the unfolded protein response (UPR) participate during cardiac remodeling and fibrosis. Here, we used isoproterenol (ISO) injection as a model for in vivo cardiac fibrosis. ISO induced significant cardiomyocyte loss and collagen deposition in the damaged areas of the endocardium. These responses were accompanied by an increase in the protein levels of the luminal ER chaperones BIP and PDI, as well as an increase in the UPR effector CHOP. The use of the chemical chaperone 4-phenylbutyric acid (4-PBA) prevented the activation of the UPR, the increase in luminal chaperones and also, leads to decreased collagen deposition, cardiomyocyte loss into the damaged zones. Our results suggest that cardiac damage and fibrosis induced in vivo by the beta-adrenergic agonist ISO are tightly related to ER stress signaling pathways, and that increasing the ER luminal folding capacity with exogenously administrated 4-PBA is a powerful strategy for preventing the development of cardiac fibrosis. Additionally, 4-PBA might prevent the loss of cardiomyocytes. Our data suggests that the attenuation of ER stress pathways with pharmacological compounds such as the chemical chaperone 4-PBA can prevent the development of cardiac fibrosis and adverse remodeling.

Simvastatin induces apoptosis by a Rho-dependent mechanism in cultured cardiac fibroblasts and myofibroblasts

Several clinical trials have shown the beneficial effects of statins in the prevention of coronary heart disease. Additionally, statins promote apoptosis in vascular smooth muscle cells, in renal tubular epithelial cells and also in a variety of cell lines; yet, the effects of statins on cardiac fibroblast and myofibroblast, primarily responsible for cardiac tissue healing are almost unknown. Here, we investigated the effects of simvastatin on cardiac fibroblast and myofibroblast viability and studied the molecular cell death mechanism triggered by simvastatin in both cell types.

METHODS

Rat neonatal cardiac fibroblasts and myofibroblasts were treated with simvastatin (0.1-10μM) up to 72h. Cell viability and apoptosis were evaluated by trypan blue exclusion method and by flow cytometry, respectively. Caspase-3 activation and Rho protein levels and activity were also determined by Western blot and pull-down assay, respectively.

RESULTS

Simvastatin induces caspase-dependent apoptosis of cardiac fibroblasts and myofibroblasts in a concentration- and time-dependent manner, with greater effects on fibroblasts than myofibroblasts. These effects were prevented by mevalonate, farnesylpyrophosphate and geranylgeranylpyrophosphate, but not squalene. These last results suggest that apoptosis was dependent on small GTPases of the Rho family rather than Ras.

CONCLUSION

Simvastatin triggered apoptosis of cardiac fibroblasts and myofibroblasts by a mechanism independent of cholesterol synthesis, but dependent of isoprenilation of Rho protein. Additionally, cardiac fibroblasts were more susceptible to simvastatin-induced apoptosis than cardiac myofibroblasts. Thus simvastatin could avoid adverse cardiac remodeling leading to a less fibrotic repair of the damaged tissues.

[Inflammation and endothelial dysfunction in patients with chronic heart failure]

BACKGROUND

In chronic heart failure (CHF), endothelial dysfunction (ED) is a consequence of an imbalance of vascular tone regulating substances. The relationship between ED and inflammation has not been fully investigated.

AIM

To assess the association between inflammation and ED in CHF.

MATERIAL AND METHODS

Forty two patients aged 56+/-14 years (80% male) with a CHF in functional capacity II-III (New York Heart Association) and an ejection fraction (FE) <40% were consecutively studied. Patients were classified according to the presence or absence of ED, evaluated by reactive vasodilation measured by ultrasound, after brachial artery compression. Circulating levels of highly sensitive C reactive protein (usCRP), tumor necrosis factor a (TNFá) and interleukin-6 (IL-6) were determined by ELISA. A group of 15 healthy subjects of similar age, were studied as controls.

RESULTS

Sixty seven percent of patients had ED. Compared to controls, patients with CHF had higher usCRP (0.58+/-0.4 and 4.9+/-7.1 mg/dl respectively, p <0.01) and IL-6 (1.38+/-0.06 and 3.1+/-1.7 mg/dl respectively, p <0.01). Compared to patients without ED, patients with CHF and ED had higher levels of usCRP (3.0+/-0.4 and 6.0+/-5.7 mg/dl respectively, p <0.01) and TNFá (0.31+/-0.26 and 1.0+/-1.1 pg/ml, p =0.02). No differences in IL-6 were found between CHF groups.

CONCLUSIONS

In CHF patients, the presence of ED was associated with increased levels of inflammatory markers.

Bispectral index monitoring may not reliably indicate cerebral ischaemia during awake carotid endarterectomy † †This study was conducted in the Department of Neurosurgery, Newcastle General Hospital, Newcastle Upon Tyne NE4 6BE, UK. Preliminary results were presented at the British Neurosurgery Research Group Meeting, Sheffield, March 29–30, 2001

BACKGROUND

Intraoperative ischaemia during carotid cross-clamping in patients undergoing carotid endarterectomy (CEA) is a major complication and prompt recognition of insufficient collateral blood supply is crucial. Electroencephalogram (EEG) is believed to be one of the useful forms of monitoring cerebrovascular insufficiency during CEA. The aim of this study was to evaluate the utility of bispectral index (BIS) monitoring, a processed EEG parameter, for the reliable detection of intraoperative cerebral ischaemia during awake CEA.

METHODS

We monitored 52 patients continuously with the BIS monitor together with assessment of neurological function (contralateral upper and lower limb strength and the verbal component of the Glasgow Coma Scale for speech) in patients undergoing awake CEA.

RESULTS

Overall mean BIS value in all patients was 96 (SD 2.9). In five patients who showed clinical evidence of cortical ischaemia during carotid cross-clamping, there was no change in the original range of BIS values throughout the procedure (96.7 [3.2]). In one patient BIS values decreased to 38 about 5 min after the incision and recovered within the next 10 min. The mean BIS value in the remaining 46 patients who did not develop clinical signs of ischaemia was 95.4 (2.6). Three cases are presented which demonstrate the inability of the BIS monitor to detect cerebral ischaemia.

CONCLUSIONS

Lack of correlation of BIS with the signs of cerebral ischaemia during CEA makes it unreliable for detection of cerebrovascular insufficiency. We conclude that awake neurological testing is the preferred method of monitoring in these patients.

Hepatitis C seroprevalence in accepted versus deferred blood-donor candidates evaluated by medical history and self-exclusion form

BACKGROUND

Hepatitis C virus (HCV) represents a viral pandemic that is five times as widespread as human immunodeficiency virus. Blood transfusion posed a major risk of HCV infection in developed countries before 1990, but the introduction of improved blood-screening measures has decreased the risk of transfusion-associated HCV infection, which may now be even lower since the introduction of screening of pooled samples by nucleic acid testing (NAT). Unfortunately, NAT is not affordable in most developing countries. The goal of this work is to assess the usefulness of both screening measures, the medical history, and the self-exclusion form to distinguish between high-risk and low-risk populations of HCV-carrier blood-donor candidates in Mexico.

STUDY DESIGN AND METHODS

From February 2002 to April 2003, 4174 consecutive candidates were enrolled in a prospective, nonrandomized and comparative study. In total, 4158 candidates were included in the analysis and divided in two groups: Group A consisted of 3101 accepted donors and Group B consisted of 1057 deferred donors according to a complete medical history and self-exclusion form. The only exclusion criteria was the lack of a signed consent form to enter the study. All candidates from both groups underwent anti-HCV detection by third-generation enzyme immunoassay (EIA). Those who had either a positive or gray-zone signal-to-cutoff ratio underwent polymerase chain reaction and a second EIA test. If the second EIA test resulted in either a positive or gray-zone signal-to-cutoff ratio, a recombinant immunoblot assay test was performed. The chi-square test was used for statistical analysis, and a p value less than 0.05 was considered significant.

RESULTS

Anti-HCV prevalence by the EIA method was as follows: 0.61 percent for Group A and 1.32 percent for Group B (p = 0.0243); whereas with recombinant immunoblot assay the prevalence was 0.19 percent for Group A and 0.47 percent for Group B (p = 0.1265). When we analyzed the polymerase chain reaction test results, the prevalence in Group A was 0.10 percent (95% confidence interval, 0.089-0.110) and in Group B was 0.47 percent (95% confidence interval, 0.439-0.500) (p = 0.0159).

CONCLUSIONS

The medical history of blood donors in conjunction with serologic screening tests helps to improve blood transfusion safety. This measure is recommended in blood banks of those countries where NAT is still unaffordable.

[Validation of a version in Spanish of the Yale-Brown Obsessive-Compulsive Scale]

INTRODUCTION

The objective of this study is to validate a version in Spanish of the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).

METHOD

We administered to 20 patients with obsessive-compulsive disorder (OCD) the Maudsley Obsessive-Compulsive Inventory (MOI) and a version in Spanish of the Y-BOCS. The application of the last one was performed by an interviewer, filmed, and then watched and rated by other 4 observers. In addition, the opinion of the treating psychiatrist about the severity of the patient's symptoms was registered. The interviewer and the observers were named raters.

RESULTS

The mean scores of the Y-BOCS assigned by the 4 observers were from 18.35 to 19.55; the maximum scores, from 34 to 35; and the minimum scores, from 1 to 5. The Pearson's correlations between raters were significant for all cases (r>0.86 and p<0.001). For all raters, Y-BOCS scores significantly correlated with MOI scores (p<0.001) and the opinion of the treating psychiatrist (p<0.05). We did not find significant correlation between the last one and MOI scores. The Cronbach's coefficients ranged from 0.8789 to 0.9488.

CONCLUSIONS

The Spanish version of the Y-BOCS is reliable, homogeneous and valid for quantification of the obsessive-compulsive symptoms, and has more correlation with the opinion of the treating psychiatrist than the MOI.

Comparative in vitro activity of moxifloxacin by E-test against Streptococcus pyogenes

Macrolides are currently used to treat Streptococcus pyogenes infections where allergy or resistance prevents the use of penicillin. However, growing macrolide resistance is now seen worldwide, with rates of 5%-40% being reported. In this context it is therefore important to have other therapeutic options. The aim of this study was to ascertain the potential role of moxifloxacin, a third-generation fluoroquinolone, in the treatment of infections caused by group A S. pyogenes. The antimicrobial susceptibilities of S. pyogenes isolated from 197 adult patients with pharyngotonsillitis were analyzed by the E-test. Twelve percent of the isolates were resistant to macrolides, and 5% showed diminished susceptibility toward penicillin; none of the strains were resistant to cefotaxime or to moxifloxacin (90% minimum inhibitory concentration, 0.25 microg/mL). Therefore, moxifloxacin may be a therapeutic option in the management of S. pyogenes infections when penicillin cannot be used or when macrolide resistance may be a local issue. Clinical studies of moxifloxacin in pharyngotonsillitis are warranted.