GAAGs, COMP, and YKL-40 as Potential Markers of Cartilage Turnover in Blood of Children with Juvenile Idiopathic Arthritis Treated with Etanercept-Relationship with ADAMTS4, ADAMTS5, and PDGF-BB.

We quantified galactosaminoglycans (GAAGs), oligomeric cartilage matrix protein (COMP), and human cartilage glycoprotein 39 (YKL-40) in blood obtained from juvenile idiopathic arthritis (JIA) before and during 2-year treatment with etanercept (ETA), as potential biomarkers of cartilage extracellular matrix (ECM) dysfunction and indicators of efficacy of biologic therapy. We also evaluated the relationship of the mentioned markers with the factors that regulate their metabolism, disintegrin and thrombospondin motif metalloproteinases 4 (ADAMTS4), ADAMTS5, and platelet-derived growth factor BB (PDGF-BB). METHODS: We studied 38 children diagnosed with JIA and 45 healthy children. We quantified GAAGs by assessing the concentration of unsaturated disaccharide units formed by digestion of isolated glycosaminoglycans with chondroitinase ABC, while COMP, YKL-40, and PDGF-BB were quantified using immunoenzymatic methods. RESULTS: Compared to the control group, GAAGs and COMP levels were significantly lower, while YKL-40 levels were higher in the blood of patients with aggressive JIA, qualified for ETA treatment. ETA therapy leading to clinical improvement simultaneously promoted normalization of COMP and YKL-40 levels, but not GAAGs. After 24 months of taking ETA, glycan levels were still significantly lower, relative to controls. GAAGs, COMP, and YKL-40 levels were significantly influenced by ADAMTS4, ADAMTS5, and PDGF-BB levels both before and during ETA treatment. CONCLUSIONS: The dynamics of changes in marker concentrations during treatment seem to indicate that measurement of COMP and YKL-40 levels can be used to assess the chondroprotective biological efficacy of therapy. In contrast, changes in GAAGs concentrations reflect systemic extracellular matrix transformations in the course of JIA.

Plasma Glycosaminoglycans in Children with Juvenile Idiopathic Arthritis Being Treated with Etanercept as Potential Biomarkers of Joint Dysfunction.

We assessed the effect of two-year etanercept (ETA) therapy on the metabolism of the cartilage extracellular matrix (ECM) in patients with juvenile idiopathic arthritis (JIA). METHODS: We performed a quantitative evaluation of glycosaminoglycans (GAGs) (performed by the multistage extraction and purification method) in blood obtained from patients before and during 24 months of ETA treatment, as potential biomarker of joint dysfunction and indicators of biological effectiveness of therapy. Since the metabolism of GAGs is related to the activity of proteolytic enzymes and prooxidant-antioxidant factors, we decided to evaluate the relationship between GAGs and the levels of metalloproteinases (MMP), i.e., MMP-1 and MMP-3 (using immunoenzymatic methods), as well as the total antioxidative status (TAS) (using the colorimetric method) in blood of the JIA patients. RESULTS: When compared to the controls, GAGs and TAS concentrations were significantly lower in patients with an aggressive course of JIA qualified for ETA treatment. MMP-1 and MMP-3 levels were significantly higher versus control values. An anti-cytokine therapy leading to clinical improvement does not lead to the normalization of any of the assessed parameters. GAGs concentration is significantly related to MMP-1, MMP-3, TAS, TOS, and CRP levels. CONCLUSION: The results of the present study indicate the necessity of constant monitoring of the dynamics of destructive processes of articular cartilage in children with JIA. We suggest that GAGs may be a useful biomarker to assess the clinical status of the extracellular matrix of joints.

Dermatan Sulfate Affects Breast Cancer Cell Function via the Induction of Necroptosis.

Dermatan sulfate (DS) is widespread in the extracellular matrix (ECM) of animal tissues. This glycosaminoglycan is characterized by a variable structure, which is reflected in the heterogeneity of its sulfation pattern. The sulfate groups are responsible for the binding properties of DS, which determine an interaction profile of this glycan. However, the detailed role of DS in biological processes such as the neoplasm is still poorly understood. The aim of the study was to assess the effects of the structural variants of DS on breast cancer cells. We found that DS isoforms from normal and fibrotic fascia as well as from intestinal mucosa were able to quickly induce oxidative stress in the cytoplasm and affect the mitochondrial function in luminal breast cancer cells. Moreover, the variants caused the necroptosis of the cells most likely via the first of these mechanisms. This death was responsible for a reduction in the viability and number of breast cancer cells. However, the dynamics and intensity of all of the DS variants-triggered effects were strongly dependent on the cell type and the structure of these molecules. The most pronounced activity was demonstrated by those variants that shared structural features with the DS from the tumor niche.

Significant Remodeling Affects the Circulating Glycosaminoglycan Profile in Adult Patients with both Severe and Mild Forms of Acute Pancreatitis.

Acute pancreatitis (AP) manifests itself either as a mild, self-limiting inflammation or a severe, systemic inflammatory process that is associated with various complications and a high mortality rate. It is unknown whether these two forms of the disease can differ in the profile of circulating glycosaminoglycans, which are molecules with huge biological reactivity due to a high density of negative electric charge. Plasma glycosaminoglycans were characterized/quantified in 23 healthy controls, 32 patients with mild AP, and 15 individuals with severe disease using electrophoresis with enzymatic identification (chondroitin sulfate and heparan sulfate) or an ELISA-based test (hyaluronan). Moreover, the correlations between the glycosaminoglycan levels and clinical parameters were evaluated. Both forms of AP showed similar remodeling of the plasma profile of the sulfated glycosaminoglycans. In contrast, only in the patients with mild AP was the level of circulating hyaluronan significantly decreased as compared to the healthy controls. Both forms of AP are associated with systemic changes in the metabolism of glycosaminoglycans. However, the alterations in hyaluronan metabolism may contribute to the disease evolution. The circulating hyaluronan may have some clinical value to predict the severity of AP and to evaluate the clinical status of patients with severe AP.

The dual role of the glycosaminoglycan chondroitin-6-sulfate in the development, progression and metastasis of cancer.

The remarkable structural heterogeneity of chondroitin sulfate (CS) and dermatan sulfate (DS) generates biological information that can be unique to each of these glycosaminoglycans (GAGs), and changes in their composition are translated into alterations in the binding profiles of these molecules. CS/DS can bind to various cytokines and growth factors, cell surface receptors, adhesion molecules, enzymes and fibrillar glycoproteins of the extracellular matrix, thereby influencing both cell behavior and the biomechanical and biochemical properties of the matrix. In this review, we summarize the current knowledge concerning CS/DS metabolism in the human cancer stroma. The remodeling of the GAG profile in the tumor niche is manifested as a substantial increase in the CS content and a gradual decrease in the proportion between DS and CS. Furthermore, the composition of CS and DS is also affected, which results in a substantial increase in the 6-O-sulfated and/or unsulfated disaccharide content, which is concomitant with a decrease in the 4-O-sulfation level. Here, we discuss the possible impact of alterations in the CS/DS sulfation pattern on the binding capacity and specificity of these GAGs. Moreover, we propose potential consequences of the stromal accumulation of chondroitin-6-sulfate for the progression and metastasis of cancer.

Dermatan sulfate is a player in the transglutaminase 2 interaction network.

Transglutaminase 2 (TG2) is a multifunctional protein that is primarily engaged in cell adhesion/signaling or shows Ca2+-dependent transglutaminase activity in the extracellular space of tissues. This latter action leads to the cross-linking of the extracellular matrix (ECM) proteins. The enhanced extracellular expression of TG2 is associated with processes such as wound healing, fibrosis or vascular remodeling that are also characterized by a high deposition of dermatan sulfate (DS) proteoglycans in the ECM. However, it is unknown whether DS may bind to TG2 or affect its function. Using the plasmon surface resonance method, we showed that DS chains, especially those of biglycan, are good binding partners for TG2. The interaction has some requirements as to the DS structure. The competitive effect of heparin on DS binding to TG2 suggests that both glycosaminoglycans occupy the same binding site(s) on the protein molecule. An occurrence of the DS-TG2 interaction was confirmed by the co-immunoprecipitation of this protein with native decorin that is a DS-bearing proteoglycan rather than with the decorin core protein. Moreover, in vivo DS is responsible for both TG2 binding and the regulation of the location of this protein in the ECM as can be suggested from an increased extraction of TG2 from the human fascia only when an enzymatic degradation of the tissue DS was conducted in the presence of the anti-collagen type I antiserum. In addition, DS with a low affinity for TG2 exerted an inhibitory effect on the protein transamidating activity most probably via the control of the accessibility of a substrate. Our data show that DS can affect several aspects of TG2 biology in both physiological and pathological conditions.

Plasma and urinary glycosaminoglycans in the course of juvenile idiopathic arthritis.

OBJECTIVES: The aim of the study was to perform analyses of plasma and urinary glycosaminoglycan isolated from juvenile idiopathic arthritis (JIA). METHODS, RESULTS: Chondroitin/dermatan sulfate (CS/DS), heparan sulfate/heparin (HS/H) and hyaluronic acid (HA) were evaluated in samples obtained from JIA patients before and after treatment. Electrophoretic analysis of GAGs identified the presence of CS, DS and HS/H in plasma of healthy subjects and JIA patients. CS were the predominant plasma GAGs constituent in all investigated subject. The plasma CS level in untreated patients was significantly decreased. Therapy resulted in an increase in this glycan level. However, plasma CS concentration still remained higher than in controls. Increased levels of DS and HA in untreated JIA patients were recorded. Anti-inflammatory treatment led to normalization of these parameters concentrations. Plasma and urinary concentrations of HS/H were similar in all groups of individuals. Urinary CS/DS and HA were decreased only in untreated patients. CONCLUSIONS: The data presented indicate that changes in plasma and urinary glycosaminoglycan occur in the course of JIA. There are probably the expression of both local articular cartilage matrix and systemic changes in connective tissue remodeling.

Complex influence of dermatan sulphate on breast cancer cells.

Tumor transformation and progression both lead to extracellular matrix remodeling, which is also reflected in an alteration in the proportion of dermatan sulphate (DS) and chondroitin sulphate (CS) and an accumulation of the latter. In addition, a significant increase in the 6-O-sulphated disaccharide contribution to the structure of both glycosaminoglycans has been observed. It is commonly accepted that CS is more permissive for tumor growth than DS. However, the detailed role of DS in tumor progression is poorly known. We tested the effects of structurally different DSs on the behavior of cultured breast cancer cells. At a high dose (10 µg/mL), all of the DSs significantly reduced cancer cell growth, although some differences in the efficiency of action were apparent. In contrast, when used at a concentration of 1 µg/mL, the examined DSs evoked different responses ranging from the stimulation to the inhibition of cancer cell proliferation. The highest stimulatory activity was associated with fibrosis-affected fascia decorin DS, which is characterized by a particularly high content of 6-O-sulphated disaccharides. Further reduction in DS concentration to 0.5 µg/mL preserved majority of biological effects which were apparent at a dose of 1 µg/mL. The enzymatic fragmentation of the DSs, particularly by chondroitinase AC I, abolished the impact exerted by 1 µg/mL of the intact DS chains and sometimes resulted in the opposite effect. In contrast to DSs, highly sulphated C-6-S exhibited no effect on the cancer cells. Our data revealed the complexity of the effects of DSs on breast cancer cells, which include both co-receptor activity and the prevention of vascular endothelial growth factor action. In addition, the biological effect of DSs is strongly dependent not only on the glycosaminoglycan structure but also on its content in the cancer environment.

Propolis modulates fibronectin expression in the matrix of thermal injury.

The aim of the study was to assess the propolis effect on fibronectin metabolism in the course of burn wounds healing process. A model of burn wound healing of pig skin was applied. The amount of the released glycoprotein was assessed by a surface plasmon resonance. The profile of extracted fibronectin components was also assessed by an electrophoresis in polyacrylamide gel, with a subsequent immunodetection by Western Blotting. Propolis burn treatment decreased the release of fibronectin components from healing wounds in relation to damages treated with silver sulfadiazine. The main reason of decreased extraction of fibronectin components from wounds treated with propolis was a substantial decrease of degradation product release of the mentioned glycoprotein, which was observed particularly from the 3rd to 5th day of the repair. Wounds treatment with propolis demonstrated, especially in relation to damages treated with silver sulfadiazine, the decreased release of synthesized fibronectin molecules. The obtained results suggest that propolis modifies fibronectin metabolism in the course of wound healing process. The influence of propolis is reflected in prevention of fibronectin biosynthesis as well as its degradation in the wound area. The above-mentioned metabolic changes may decrease the risk of complications in the repair wounds process.

Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue.

Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization.

Propolis modulates vitronectin, laminin, and heparan sulfate/heparin expression during experimental burn healing.

OBJECTIVE: This study was aimed at assessing the dynamics of vitronectin (VN), laminin (LN), and heparan sulfate/heparin (HS/HP) content changes during experimental burn healing. METHODS: VN, LN, and HS/HP were isolated and purified from normal and injured skin of domestic pigs, on the 3rd, 5th, 10th, 15th, and 21st days following thermal damage. The wounds were treated with apitherapeutic agent (propolis), silver sulfadiazine (SSD), physiological salt solution, and propolis vehicle. VN and LN were quantified using an immunoenzymatic assay and HS/HP was estimated by densitometric analysis. RESULTS: Propolis treatment stimulated significant increases in VN, LN, and HS/HP contents during the initial phase of study, followed by a reduction in the estimated extracellular matrix molecules. Similar patterns, although less extreme, were observed after treatment with SSD. CONCLUSIONS: The beneficial effects of propolis on experimental wounds make it a potential apitherapeutic agent in topical burn management.

The role of decorin and biglycan dermatan sulfate chain(s) in fibrosis-affected fascia.

Organ fibrosis is associated with excessive deposition of dermatan sulfate (DS) in the extracellular matrix (ECM) of the affected tissue. However, the significance of DS in fibrosis process is poorly known. Thus, we have analyzed both in vitro and in vivo the binding potential toward fibroblast growth factor-2, platelet-derived growth factor BB and fibronectin (FN) of DS representing glycosaminoglycan (GAG) chains of two proteoglycans decorin and biglycan derived from fascia undergoing fibrosis due to Dupuytren's disease. Moreover, to investigate the relation between DS structure and its binding properties to above ligands, we have also studied the interactions of the GAG chains from normal porcine skin decorin and biglycan. The examined interactions, especially those engaging extractable pool of both human and porcine decorin DS, are characterized by very high affinity and low capacity. Moreover, the presence of iduronate residues is not essential for the DS binding to all studied ligands and the interactions more strongly depend on the GAG sulfation pattern. All investigated interactions have biological relevance as judged from the coexistence of decorin (and biglycan) DS, both growth factors and FN in supra-molecular complexes localized in ECM of both fibrous and normal human fascia. Moreover, these complexes also include collagen type III. It seems that fascia fibrosis process when compared with physiological circumstances is associated with the preservation of at least some functions of decorin and biglycan DSs such as the regulation of growth factor bioavailability and most probably influence FN fibrillogenesis as well as coupling of various fibrilar matrix element assembly.

Platelet derived growth factor BB is a ligand for dermatan sulfate chain(s) of small matrix proteoglycans from normal and fibrosis affected fascia.

Structural requirements of the short isoform of platelet derived growth factor BB (PDGF-BB) to bind dermatan sulfate (DS)/chondroitin sulfate (CS) are unknown. Meanwhile the interaction may be important for tissue repair and fibrosis which involve both high activity of PDGF-BB and matrix accumulation of DS. We examined by the solid phase assay the growth factor binding to DS chains of small proteoglycans from various fasciae as well as to standard CSs. Before the assay a structural analysis of DSs and CSs was accomplished involving the evaluation of their epimerization and/or sulfation patterns. In addition, in vivo acceptors for PDGF-BB in fibrosis affected fascia were detected. PDGF-BB binding sites on DSs/CSs are located in long chain sections with the same type of hexuronate isomer however without any apparent preference to glucuronate or iduronate residues. Alternatively, the interaction seems to involve two shorter DS chain sections assembling disaccharides with the same type of hexuronate isomer which are separated by disaccharide(s) with another hexuronate one. Moreover, DS/CS affinity to the growth factor most probably depends on an accumulation of di-2,4-O-sulfated disaccharides in binding site while the presence of 6-O-sulfated N-acetyl-galactosamine residues rather attenuates the binding. All examined fascia DSs and standard CSs showed significant PDGF-BB binding capability with the highest affinity found for normal palmar fascia decorin DS. In fibrosis affected palmar fascia DS/CS proteoglycans are able to form with PDGF-BB supramolecular complexes also including other matrix components such as type III collagen and fibronectin which bind the growth factor covalently. Our results suggest that DS chains of fascia matrix small PGs may regulate PDGF-BB availability leading to restriction of fibrosis associated with Dupuytren's disease or to control of normal fascia repair.

[Serum glycosaminoglycans in Graves' disease patients]. / Glikozoaminoglikany surowicy krwi osób z choróba Gravesa i Basedowa.

The aim of the study was to determine the blood serum sulfated glycosaminoglycans (GAGs) and hyaluronic acid (HA) concentration of Graves' disease patients before treatment and after attainment of the euthyroid state. The study was carried out on the blood serum obtained from 17 patients with newly recognised Graves' disease and from the same patients after attainment of the euthyroid state. Graves' patients had not any clinical symptoms neither of ophthalmopathy nor pretibial myxedema. GAGs were isolated from the blood serum by the multistage extraction and purification using papaine hydrolysis, alkali elimination, as well as cetylpyridium chloride binding. Total amount of GAGs was quantified by the hexuronic acids assay. HA content in obtained GAGs sample was evaluated by the ELISA method. Increased serum concentration of sulfated GAGs in non-treated Graves' disease patients was found. Similarly, serum HA level in untreated patients was significantly elevated. The attainment of euthyroid state was accompanied by the decreased serum sulfated GAGs level and by normalization of serum HA concentration. In conclusion, the results obtained demonstrate that the alterations of GAGs metabolism connected with Graves' disease can lead to systemic changes of the extracellular matrix properties.

Alterations of glycosaminoglycan metabolism in the development of diabetic complications in relation to metabolic control.

Disturbed metabolism of glycosaminoglycans (GAGs) has been proposed to play an important role in the pathogenesis of late diabetic complications. The effect of diabetic complications and metabolic control on both total serum GAGs content and the serum activity of lysosomal glycosidases (N-acetyl-beta-D-glucosaminidase, alpha-L-fucosidase, beta-D-galactosidase, and alpha-D-mannosidase) contributing to GAGs degradation, was investigated in 48 patients with type 2 diabetes mellitus. The activity of beta-D-glucosidase and acid phosphatase, the lysosomal enzymes unrelated to GAGs metabolism, was determined for comparison. The elevated serum total GAG concentration in diabetic patients was strongly and positively influenced by poor metabolic compensation of diabetes and the presence of vascular complications. A similar tendency has been shown in regard to the activity of enzymes involved in GAG degradation, especially N-acetyl-beta-D-glucosaminidase, alpha-L-fucosidase and beta-D-galactosidase. Furthermore, the total serum GAG concentrations, as well as the activity of lysosomal enzymes involved in the extracellular matrix degradation, closely followed metabolic compensation, regardless of diabetic vascular complications. Thus, we suggest that increased values of the investigated parameters may indicate the degree of endothelial cell dysfunction and may be useful to predict the development of diabetic vascular pathology.

The influence of physical and chemical agents on photooxidation of porcine pericardial collagen.

Photooxidation is a method of tissue fixation resulting in protein crosslinking due to illumination in the presence of a dye. The aim of the study was to evaluate the impact of dyes, photooxidation time and the type of applied light on the porcine pericardial collagen crosslinking. The collagen modifications were evaluated on the basis of pericardial sensitivity to pepsin digestion. The hydrolysate components were evaluated qualitatively and quantitatively. All hydrolysates contained collagen alpha chains, their aggregates and degradation products. Methylene blue and methylene green-mediated 4 h photooxidation in the presence of visible light caused similar decrease in pericardium sensitivity to pepsin. However, both fixation types generated remarkable amounts of alpha chain degradation products. The prolongation of photooxidation time to 8 h did not increase the pericardial sample resistance to pepsin. Moreover, these sample hydrolysates revealed an elevated alpha chain content. Violet light mediated photooxidation did not alter pericardial sensitivity to pepsin when compared with fixation under visible light. Nevertheless, violet light fixed tissues displayed a decrease in collagen degradation products. The application of violet light in photooxidation of porcine pericardium will probably allow to obtain enzyme resistant bioprostheses with better mechanical properties compared with those obtained after visible light mediated process.

Alterations in the extracellular matrix proteoglycan profile in Dupuytren's contracture affect the palmar fascia.

Dupuytren's disease is a palmar fibromatosis associated with changes in fibroblast activity that also affect the metabolism of extracellular matrix components. In contrast to disease connected alterations in collagen and non-collagenous glycoproteins (mainly fibronectin), the metabolism of proteoglycans, being glycosaminoglycan modified glycoproteins, is poorly understood. Thus, the aim of the present study was the characterization of matrix proteoglycans (PGs) derived from normal fascia and Dupuytren's fascia. Extracted and purified PGs (particularly small PGs) were analysed for content, molecular mass, immunoreactivity and glycosaminoglycan chain structure. The matrix of normal fascia mainly contains decorin [small dermatan sulfate (DS) PG] with biglycan (another small DSPG) and large chondroitin sulfate(CS)/DSPG representing minor components. Dupuytren's disease is associated with the remodeling of matrix PG composition. The most prominent alteration is an accumulation of biglycan frequently bearing DS chains with higher molecular masses. Moreover, the amount of large CS/DSPG is increased. In contrast, decorin displays changes affecting mainly DS chain structure reflected in (i) an increase in some chain molecular masses, (ii) an enhanced content of iduronate disaccharide clusters, and (iii) oversulfation of disaccharide repeats. The PG alterations observed in Dupuytren's fascia may influence the matrix properties and contribute to disease progression.

[Genetic aspect of Dupuytren's diseases]. / Choroba dupuytrena w aspekcie genetycznym.

Dupuytren's disease is a connective tissue disorder leading to the shortening of the palmar aponeurosis and progressive digital flexion deformity. Despite decades of both scientific and clinical investigations the precise etiology and tissue origin of Dupuytren's disease remains unclear. Several authors focused their studies on the genetics of Dupuytren's disease and postulated either autosomal dominant or autosomal recessive mode of inheritance. The limited number of members of families affected with the disease makes it difficult to determine the mode of inheritance. A particular difficulty is the late age of the onset of Dupuytren's disease, which in most cases limits examination to two generations. Age-related, dominant inheritance is a mode favored by several authors whereas others consider autosomal recessive inheritance as a possible explanation for sporadic cases of Dupuytren's disease. A gene that increases susceptibility to the disease may do so by rendering the tissue more sensitive to the effects of environmental exposures. This article summarizes current studies on various modes of inheritance in Dupuytren's disease.

Graves' disease-associated changes in the serum lysosomal glycosidases activity and the glycosaminoglycan content.

BACKGROUND: This study was undertaken to elucidate the influence of Graves' hyperthyroidism upon the metabolism of proteoglycans (PGs), the extracellular matrix (ECM) components. We determined the serum activity of lysosomal hydrolases contributing to GAGs degradation (N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, beta-D-galactosidase, alpha-D-mannosidase, beta-D-xylosidase and alpha-L-fucosidase). An effect of Graves' hyperthyroidism on total serum GAGs content was also analysed. METHODS: Blood samples were taken from 30 patients with newly diagnosed Graves' disease, prior to antithyroid treatment and after attainment of euthyroid state, as well as from 30 healthy individuals. RESULTS: The activity of all investigated enzymes involved in GAGs degradation was found markedly increased in blood serum of patients with hyperthyroidism, except for alpha-D-mannosidase, which was not significantly modified. Antithyroid treatment with thiamazole resulted in normalization of the lysosomal glycosidases activity, so they no longer differed from the healthy subjects. The total glycosaminoglycans content in blood serum of patients with newly diagnosed untreated Graves' disease significantly increased compared to control group. Following thiamazole therapy total serum amount of GAGs decreased significantly, but was still markedly increased as compared to serum of healthy individuals. CONCLUSIONS: The obtained results indicate that Graves' hyperthyroidism is associated with extracellular matrix components' alterations. Furthermore, we suggest that general increase of the serum lysosomal glycosidases activity and serum GAG concentration may both result from the same reason, i.e. excessive reactive oxygen species formation in the course of hyperthyroidism due to Graves' disease.

[Methods of collagenous tissue fixation in the preparation of bioprostheses]. / Metody stabilizacji materialu kolagenowego wykorzystywane w bioprotetyce.

The use of biological materials in construction of bioprostheses requires the application of different chemical or physical procedures of fixation increasing bioprostheses resistance to enzymatic or chemical degradation and reducing their antigenicity. Methods typically concentrate on creating additional intra- and intermolecular chemical bonds between collagen molecules. This review focuses on the various methods of stabilization of collagenous tissues including chemical fixatives and physical agents.