End-to-end arterial anastomosis with fibrin glue in larger arteries: histology, hydroxyproline concentration and tensile strength study in carotids of rabbits

A anastomose arterial término-terminal é demorada, requer tempo prolongado de oclusão vascular e esta associada a necrose focal, infiltração leucocitária e, conseqüentemente, à fibrose e calcificação da parede arterial. A cola de fibrina é uma alternativa para a anastomose microvascular e pode evitar estas alterações com menor aderência aos tecidos vizinhos e melhor coaptação das bordas arteriais. OBJETIVO: Comparar o processo cicatricial de anastomoses convencionais com anastomoses feitas com cola de fibrina em artérias maiores. MÉTODOS: em 22 coelhos, ambas carótidas foram seccionadas transversalmente e reconstruídas por meio de anastomose término-terminal com 4 pontos simples de reparo e cola de fibrina de um lado (G1), e com 8 pontos separados do outro lado (G2). Após 3 e 15 dias, os animais foram destinados aleatoriamente para estudo de força tênsil concentração de hidroxiprolina (8 animais) e avaliação histológica das anastomoses (3 animais). As lâminas histológicas foram coradas pelo HE Masson e Picrossirius polarização (PSP). RESULTADOS: Após 3 e 15 dias a força tênsil aumenta em ambos os grupos, de 280,0± 32,6g para 432,2± 131,2g no Grupo 1 e de 221,4± 72,4g para 452,2± 132,0g no Grupo 2; sem diferença estatística entre os grupos em cada período. A concentração de hidroxiprolina expressa como razão hidroxiprolina/proteína, variou de 0,0816± 0,0651 para 0,0622± 0,0184 no Grupo 1 e de 0,0734± 0,0577 para 0,0460± 0,0271 no Grupo 2; sem diferença estatística entre os períodos e grupos. Os estudos histológicos mostraram discreto aumento das reações de inflamação e reparação no Grupo 2. A técnica PSP mostrou predomínio do colágeno tipo I em relação do colágeno tipo II nas anastomoses de ambos os grupos, sem diferença expressiva entre esses grupos. CONCLUSÃO: A anastomose com a cola de fibrina foi menos lesiva para a parede arterial do que a anastomose convencional. Mesmo usando menos pontos, as características de força tênsil e de cicatrização da anastomose com cola de fibrina foram similares em ambos os grupos. Os tempos de realização das anastomoses foram significativamente maiores do que na anastomose convencional.

Application of carbon composite adsorbents prepared from coffee waste and clay for the removal of reactive dyes from aqueous solutions

A novel carbon composite was prepared from a mixture of coffee waste and clay with inorganic:organic ratio of 1.3 (CC-1.3). The mixture was pyrolysed at 700 °C. Considering the application of this adsorbent for removal of anionic dyes, the CC-1.3 was treated with a 6 mol L^-1 HCl for 24 h to obtain ACC-1.3. Fourier transform infrared (FTIR), N₂ adsorption/desorption curves, scanning electron microscope (SEM) and powder X-ray diffractometry (XRD) were used for characterisation of CC-1.3 and ACC-1.3 carbon adsorbents. The adsorbents were effectively utilised for removal of reactive blue 19 (RB-19) and reactive violet 5 (RV-5) textile dyes from aqueous solutions. The maximum amounts of RB-19 dye adsorbed at 25 °C are 63.59 (CC-1.3) and 110.6 mg g^-1 (ACC-1.3), and 54.34 (CC-1.3) and 94.32 mg g^-1 (ACC-1.3) for RV-5 dye. Four simulated dye-house effluents were used to test the application of the adsorbents for treatment of effluents.

MyD88 Signaling Pathway Is Involved in Renal Fibrosis by Favoring a T(H)2 Immune Response and Activating Alternative M2 Macrophages

Inflammation contributes to the pathogenesis of chronic kidney disease (CKD). Molecules released by the inflamed injured tissue can activate toll-like receptors (TLRs), thereby modulating macrophage and CD4+ T-cell activity. We propose that in renal fibrogenesis, M2 macrophages are recruited and activated in a T helper subset 2 cell (TH2)-prone inflammatory milieu in a MyD88- dependent manner. Mice submitted to unilateral ureteral ligation (UUO) demonstrated an increase in macrophage infiltration with collagen deposition after 7 d. Conversely, TLR2, TLR4 and MyD88 knockout (KO) mice had an improved renal function together with diminished TH2 cytokine production and decreased fibrosis formation. Moreover, TLR2, TLR4 and MyD88 KO animals exhibited less M2 macrophage infiltration, namely interleukin (IL)-10+ and CD206+ CD11bhigh cells, at 7 d after surgery. We evaluated the role of a TH2 cytokine in this context, and observed that the absence of IL-4 was associated with better renal function, decreased IL-13 and TGF- β levels, reduced arginase activity and a decrease in fibrosis formation when compared with IL-12 KO and wild-type (WT) animals. Indeed, the better renal outcomes and the decreased fibrosis formation were restricted to the deficiency of IL-4 in the hematopoietic compartment. Finally, macrophage depletion, rather than the absence of T cells, led to reduced lesions of the glomerular filtration barrier and decreased collagen deposition. These results provide evidence that future therapeutic strategies against renal fibrosis should be accompanied by the modulation of the M1:M2 and TH1:TH2 balance, as TH2 and M2 cells are predictive of fibrosis toward mechanisms that are sensed by innate immune response and triggered in a MyD88-dependent pathway.

Vascular dysfunction by myofibroblast activation in patients with idiopathic pulmonary fibrosis and prognostic significance

In this study, we demonstrated the importance of telomerase protein expression and determined the relationships among telomerase, endothelin-1 (ET-1) and myofibroblasts during early and late remodeling of parenchymal and vascular areas in usual interstitial pneumonia (UIP) using 27 surgical lung biopsies from patients with idiopathic pulmonary fibrosis (IPF). Telomerase+, myofibroblasts alpha-SMA+, smooth muscle cells caldesmon+, endothelium ET-1+ cellularity, and fibrosis severity were evaluated in 30 fields covering normal lung parenchyma, minimal fibrosis (fibroblastic foci), severe ( mural) fibrosis, and vascular areas of UIP by the point-counting technique and a semiquantitative score. The impact of these markers was determined in pulmonary functional tests and follow-up until death from IPF. Telomerase and ET-1 expression was significantly increased in normal and vascular areas compared to areas of fibroblast foci. Telomerase and ET-1 expression was inversely correlated with minimal fibrosis in areas of fibroblast foci and directly associated with severe fibrosis in vascular areas. Telomerase activity in minimal fibrosis areas was directly associated with diffusing capacity of the lung for oxygen/alveolar volume and ET-1 expression and indirectly associated with diffusing capacity of the lungs for carbon monoxide and severe fibrosis in vascular areas. Cox proportional hazards regression revealed a low risk of death for females with minimal fibrosis displaying high telomerase and ET-1 expression in normal areas. Vascular dysfunction by telomerase/ET-1 expression was found earlier than vascular remodeling by myofibroblast activation in UIP with impact on IPF evolution, suggesting that strategies aimed at preventing the effect of these mediators may have a greater impact on patient outcome.

Potent antifibrotic activity of mTOR inhibitors sirolimus and everolimus but not of cyclosporine A and tacrolimus in experimental liver fibrosis

Recurrence of chronic hepatitis C and progressive fibrosis in liver transplants is frequent and impairs both graft and patient survival. Whether or not the choice of immunosuppression affects progression of fibrosis remains unclear. The aim of the present study was to compare the potential of the commonly used immunosuppressants to halt experimental liver fibrosis progression.

Interleukin-17 signaling in inflammatory, Kupffer cells, and hepatic stellate cells exacerbates liver fibrosis in mice

Interleukin (IL)-17 signaling has been implicated in lung and skin fibrosis. We examined the role of IL-17 signaling in the pathogenesis of liver fibrosis in mice.

Impact of Lifetime Alcohol Use on Liver Fibrosis in a Population of HIV-Infected Patients With and Without Hepatitis C Coinfection

BACKGROUND: The effect of alcohol on liver disease in HIV infection has not been well characterized. METHODS: We performed a cross-sectional multivariable analysis of the association between lifetime alcohol use and liver fibrosis in a longitudinal cohort of HIV-infected patients with alcohol problems. Liver fibrosis was estimated with 2 noninvasive indices, "FIB-4," which includes platelets, liver enzymes, and age; and aspartate aminotransferase/platelet ratio index ("APRI"), which includes platelets and liver enzymes. FIB-4 <1.45 and APRI <0.5 defined the absence of liver fibrosis. FIB-4 >3.25 and APRI >1.5 defined advanced liver fibrosis. The main independent variable was lifetime alcohol consumption (<150 kg, 150 to 600 kg, >600 kg). RESULTS: Subjects (n = 308) were 73% men, mean age 43 years, 49% with hepatitis C virus (HCV) infection, 60% on antiretroviral therapy, 49% with an HIV RNA load <1,000 copies/ml, and 18.7% with a CD4 count <200 cells/mm(3) . Forty-five percent had lifetime alcohol consumption >600 kg, 32.7% 150 to 600 kg, and 22.3% <150 kg; 33% had current heavy alcohol use, and 69% had >9 years of heavy episodic drinking. Sixty-one percent had absence of liver fibrosis and 10% had advanced liver fibrosis based on FIB-4. In logistic regression analyses, controlling for age, gender, HCV infection, and CD4 count, no association was detected between lifetime alcohol consumption and the absence of liver fibrosis (FIB-4 <1.45) (adjusted odds ratio [AOR] = 1.12 [95% CI: 0.25 to 2.52] for 150 to 600 kg vs. <150 kg; AOR = 1.11 [95% CI: 0.52 to 2.36] for >600 kg vs. <150 kg; global p = 0.95). Additionally, no association was detected between lifetime alcohol use and advanced liver fibrosis (FIB-4 >3.25). Results were similar using APRI, and among those with and without HCV infection. CONCLUSIONS: In this cohort of HIV-infected patients with alcohol problems, we found no significant association between lifetime alcohol consumption and the absence of liver fibrosis or the presence of advanced liver fibrosis, suggesting that alcohol may be less important than other known factors that promote liver fibrosis in this population.

Increased airway smooth muscle mass in children with asthma, cystic fibrosis, and non-cystic fibrosis bronchiectasis

RATIONALE: Structural alterations to airway smooth muscle (ASM) are a feature of asthma and cystic fibrosis (CF) in adults. OBJECTIVES: We investigated whether increase in ASM mass is already present in children with chronic inflammatory lung disease. METHODS: Fiberoptic bronchoscopy was performed in 78 children (median age [IQR], 11.3 [8.5-13.8] yr): 24 with asthma, 27 with CF, 16 with non-CF bronchiectasis (BX), and 11 control children without lower respiratory tract disease. Endobronchial biopsy ASM content and myocyte number and size were quantified using stereology. MEASUREMENTS AND MAIN RESULTS: The median (IQR) volume fraction of subepithelial tissue occupied by ASM was increased in the children with asthma (0.27 [0.12-0.49]; P < 0.0001), CF (0.12 [0.06-0.21]; P < 0.01), and BX (0.16 [0.04-0.21]; P < 0.01) compared with control subjects (0.04 [0.02-0.05]). ASM content was related to bronchodilator responsiveness in the asthmatic group (r = 0.66, P < 0.01). Median (IQR) myocyte number (cells per mm(2) of reticular basement membrane) was 8,204 (5,270-11,749; P < 0.05) in children with asthma, 4,504 (2,838-8,962; not significant) in children with CF, 4,971 (3,476-10,057; not significant) in children with BX, and 1,944 (1,596-6,318) in control subjects. Mean (SD) myocyte size (mum(3)) was 3,344 (801; P < 0.01) in children with asthma, 3,264 (809; P < 0.01) in children with CF, 3,177 (873; P < 0.05) in children with BX, and 1,927 (386) in control subjects. In all disease groups, the volume fraction of ASM in subepithelial tissue was related to myocyte number (asthma: r = 0.84, P < 0.001; CF: r = 0.81, P < 0.01; BX: r = 0.95, P < 0.001), but not to myocyte size. CONCLUSIONS: Increases in ASM (both number and size) occur in children with chronic inflammatory lung diseases that include CF, asthma, and BX.

Attenuation of fibrosis in vitro and in vivo with SPARC siRNA.

INTRODUCTION: SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs. METHODS: In in vitro studies, skin fibroblasts obtained from a Tgfbr1 knock-in mouse (TBR1CA; Cre-ER) were transfected with SPARC siRNA. Gene and protein expressions of the Col1a2 and the Ctgf were examined by real-time RT-PCR and Western blotting, respectively. In in vivo studies, C57BL/6 mice were induced for skin and lung fibrosis by bleomycin and followed by SPARC siRNA treatment through subcutaneous injection and intratracheal instillation, respectively. The pathological changes of skin and lungs were assessed by hematoxylin and eosin and Masson's trichrome stains. The expression changes of collagen in the tissues were assessed by real-time RT-PCR and non-crosslinked fibrillar collagen content assays. RESULTS: SPARC siRNA significantly reduced gene and protein expression of collagen type 1 in fibroblasts obtained from the TBR1CA; Cre-ER mouse that was induced for constitutively active TGF-beta receptor I. Skin and lung fibrosis induced by bleomycin was markedly reduced by treatment with SPARC siRNA. The anti-fibrotic effect of SPARC siRNA in vivo was accompanied by an inhibition of Ctgf expression in these same tissues. CONCLUSIONS: Specific inhibition of SPARC effectively reduced fibrotic changes in vitro and in vivo. SPARC inhibition may represent a potential therapeutic approach to fibrotic diseases.

Reliable prediction of clinical outcome in patients with chronic HCV infection and compensated advanced hepatic fibrosis: a validated model using objective and readily available clinical parameters.

OBJECTIVE Reliable tools to predict long-term outcome among patients with well compensated advanced liver disease due to chronic HCV infection are lacking. DESIGN Risk scores for mortality and for cirrhosis-related complications were constructed with Cox regression analysis in a derivation cohort and evaluated in a validation cohort, both including patients with chronic HCV infection and advanced fibrosis. RESULTS In the derivation cohort, 100/405 patients died during a median 8.1 (IQR 5.7-11.1) years of follow-up. Multivariate Cox analyses showed age (HR=1.06, 95% CI 1.04 to 1.09, p<0.001), male sex (HR=1.91, 95% CI 1.10 to 3.29, p=0.021), platelet count (HR=0.91, 95% CI 0.87 to 0.95, p<0.001) and log10 aspartate aminotransferase/alanine aminotransferase ratio (HR=1.30, 95% CI 1.12 to 1.51, p=0.001) were independently associated with mortality (C statistic=0.78, 95% CI 0.72 to 0.83). In the validation cohort, 58/296 patients with cirrhosis died during a median of 6.6 (IQR 4.4-9.0) years. Among patients with estimated 5-year mortality risks <5%, 5-10% and >10%, the observed 5-year mortality rates in the derivation cohort and validation cohort were 0.9% (95% CI 0.0 to 2.7) and 2.6% (95% CI 0.0 to 6.1), 8.1% (95% CI 1.8 to 14.4) and 8.0% (95% CI 1.3 to 14.7), 21.8% (95% CI 13.2 to 30.4) and 20.9% (95% CI 13.6 to 28.1), respectively (C statistic in validation cohort = 0.76, 95% CI 0.69 to 0.83). The risk score for cirrhosis-related complications also incorporated HCV genotype (C statistic = 0.80, 95% CI 0.76 to 0.83 in the derivation cohort; and 0.74, 95% CI 0.68 to 0.79 in the validation cohort). CONCLUSIONS Prognosis of patients with chronic HCV infection and compensated advanced liver disease can be accurately assessed with risk scores including readily available objective clinical parameters.

Reactive oxygen and nitrogen intermediates in the relationship between mammalian hosts and microbial pathogens

This review summarizes recent evidence from knock-out mice on the role of reactive oxygen intermediates and reactive nitrogen intermediates (RNI) in mammalian immunity. Reflections on redundancy in immunity help explain an apparent paradox: the phagocyte oxidase and inducible nitric oxide synthase are each nonredundant, and yet also mutually redundant, in host defense. In combination, the contribution of these two enzymes appears to be greater than previously appreciated. The remainder of this review focuses on a relatively new field, the basis of microbial resistance to RNI. Experimental tuberculosis provides an important example of an extended, dynamic balance between host and pathogen in which RNI play a major role. In diseases such as tuberculosis, a molecular understanding of host–pathogen interactions requires characterization of the defenses used by microbes against RNI, analogous to our understanding of defenses against reactive oxygen intermediates. Genetic and biochemical approaches have identified candidates for RNI-resistance genes in Mycobacterium tuberculosis and other pathogens.

Endogenous ursodeoxycholic acid and cholic acid in liver disease due to cystic fibrosis

Focal biliary cirrhosis causes significant morbidity and mortality in cystic fibrosis (CF). Although the mechanisms of pathogenesis remain unclear, bile acids have been proposed as potential mediators of liver injury. This study examined bile acid composition in CF and assessed altered bile acid profiles to determine if they are associated with incidence and progression of liver injury in CF-associated liver disease (CFLD). Bile acid composition was determined by gas-liquid chromatography/mass spectrometry in bile, urine, and serum samples from 30 children with CFLD, 15 children with CF but without liver disease (CFnoLD)), and 43 controls. Liver biopsies from 29 CFLD subjects were assessed histologically by grading for fibrosis stage, inflammation, and disruption of the limiting plate. A significantly greater proportion of endogenous biliary ursodeoxycholic acid (UDCA) was demonstrated in CFnoLD subjects vs. both CFLD subjects and controls (2.4- and 2.2-fold, respectively; ANOVA, P = .04), and a 3-4 fold elevation in endogenous serum UDCA concentration was observed in both CFLD subjects and CFnoLD subjects vs. controls (ANOVA, P < .05). In CFLD, there were significant correlations between serum cholic acid and hepatic fibrosis, inflammation, and limiting plate disruption as well as the ratio of serum cholic acid/chenodeoxycholic acid to hepatic fibrosis, inflammation, and limiting plate disruption. In conclusion, elevated endogenous UDCA in CFnoLD suggests a possible protective role against liver injury in these patients. The correlation between both cholic acid and cholic acid/chenodeoxycholic acid levels with histological liver injury and fibrosis progression suggests a potential monitoring role for these bile acids in CFLD.

Compatibilisation and stabilisation of immiscible polymer blends by reactive processing

The main objectives of this research were to develop optimised chemical compositions and reactive processing conditions for grafting a functional monomer maleic anhydride (MA) in polypropylene (PP), ethylene propylene diene monomer (EPDM) and mixtures of PP-EPDM, and to optimise synthetic routes for production of PP/EPDM copolymers for the purpose of compatibilisation of PP/EPDM blends. The MA-functionalisation was achieved using an internal mixer in the presence of low concentrations (less than 0.01 molar ratio) of a free radical initiator. Various methods were used to purify MA-functionalised PP and the grafting yield was determined using either FTIR or titrametry. The grafting yield of MA alone, which due to its low free-radical reactivity towards polymer macroradicals, was accompanied by severe degradation in the case of PP and crosslinking for EPDM. In the case of MA-functionalised PP/EPDM, both degradation and crosslinking occurred though not to a great extent. The use of tri-functional coagents e.g. trimethylopropane triacrylates (TRIS) with MA, led to high improvement of the grafting yield of MA on the polymers. This is almost certainly due to high free-radical activity of TRIS leading to copolymerisation of MA and TRIS which was followed by grafting of the copolymer onto the polymer backbone. In the case of PP, the use of coagent was also found to reduce the polymer degradation. PP/EPDM copolymers with optimum tensile properties were synthesised using a 'one-step' continues reactive processing procedure. This was achieved firstly by functionalisation of a mixture of PP (higher w/w ratio) and EPDM (low w/w ratio) with MA, in the presence of the coagent TRIS and a small concentration of a free radical initiator. This was then followed by an imidisation reaction with the interlinking agent hexamethylene diamine (HEMDA). Small amount of copolymers, up to 5 phr, which were interlinked with up to 15 phr of HEMDA, were sufficient to compatibilise PP/EPDM75/25 blends resulting in excellent tensile properties compared to binary PP/EPDM 75/25 blend. Improvement in blend's compatibility and phases-stabilisation (observed through tensile and SEM analysis) was shown in all cases with significant interphases adhesion improvement between PP and EPDM, and reduction in domain size across the fractured surface indicating efficient distribution of the compatibiliser.

Functionalisation of polymers: reactive processing, structure and performance characteristics

The main aim of this work was to study the effect of two comonomers, trimethylolpropane trimethacrylate (TRIS) and divinylbenzene (DVB) on the nature and efficiency of grafting of two different monomers, glycidyl methacrylate (GMA) and maleic anhydride (MA) on polypropylene (P) and on natural rubber (NR) using reactive processing methods. Four different peroxides, benzoyl peroxide (BPO), dicumyl peroxide (DCP), 2,5-dimethyl-2,5-bis-(tert-butyl peroxy) hexane (t-101), and 1,1-di(tert-butylperoxy)-3,3,5-trimethyl cyclohexene (T-29B90) were examined as free radical initiators. An appropriate methodology was established and chemical composition and reactive processing parameters were examined and optimised. It was found that in the absence of the coagents DVB and TRIS, the grafting degree of GMA and MA increased with increasing peroxide concentration, but the level of grafting was low and the homopolymerisaton of GMA and the crosslinking of NR or chain scission of PP were identified as the main side reactions that competed with the desired grafting reaction in the polymers. At high concentrations of the peroxide T-101 (>0.02 mr) cross linking of NR and chain scission of PP became dominant and unacceptable. An attempt to add a reactive coagent, e.g. TRIS during grafting of GMA on natural rubber resulted in excessive crosslinking because of the very high reactivity of this comonomer with the C=C of the rubber. Therefore, the use of any multifunctional and highly reactive coagent such as TRIS, could not be applied in the grafting of GAM onto natural rubber. In the case of PP, however, the use of TRIS and DVB was shown to greatly enhance the grafting degree and reduce the chain scission with very little extent of monomer homopolymerisation taking place. The results showed that the grafting degree was increased with increasing GMA and MA concentrations. It was also found that T-101 was a suitable peroxide to initiate the grafting reaction of these monomers on NR and PP and the optimum temperature for this peroxide was =160°C. A very preliminary work was also conducted on the use of the functionalised-PP (f-PP) in the absence and presence of the two comonomers (f-PP-DVB or f-PP-TRIS) for the purpose of compatibilising PP-PBT blends through reactive blending. Examination of the morphology of the blends suggested that an effective compatibilisation has been achieved when using f-PP-DVB and f-PP-TRIS, however more work is required in this area.

Transglutaminase inhibition reduces fibrosis and preserves function in experimental chronic kidney disease

Progressive tissue fibrosis is involved in debilitating diseases that affect organs including the lungs, liver, heart, skin, and kidneys. Recent evidence suggests that tissue transglutaminase, an enzyme that crosslinks proteins, may be involved in tissue fibrosis by crosslinking and stabilizing the extracellular matrix or by recruiting and activating the large latent transforming growth factor (TGF)-β1 complex. We treated rats that had undergone 5/6-nephrectomy with two different irreversible inhibitors of transglutaminase and found that both prevented a decline in kidney function and reduced the development of glomerulosclerosis and tubulointerstitial fibrosis by up to 77% and 92%, respectively. Treatment reduced the accumulation of collagen I and collagen III, with the primary mechanism of action being direct interference with the crosslinking of extracellular matrix rather than altered regulation of TGFβ1. We conclude that inhibition of transglutaminase offers a potential therapeutic option for chronic kidney disease and other conditions that result from tissue fibrosis. Copyright © 2007 by the American Society of Nephrology.