Introdução: a cistite intersticial é doença crônica do trato urinário inferior cujos sintomas são: aumento da freqüência urinária, nictúria, dor pélvica ou perineal que piora com a repleção vesical e melhora com a micção. A etiopatogenia não é totalmente conhecida, mas há indícios de que os glicosaminoglicanos e proteoglicanos que revestem o urotélio vesical possam participar da sua gênese. A perda destes componentes protetores facilitaria o contato de íons e solutos presentes na urina com as porções mais profundas do urotélio desencadeando e perpetuando um processo inflamatório local. Para tentar entender seu metabolismo, investigamos o comportamento dos glicosaminoglicanos na urina e no tecido (biópsia do urotélio vesical) de pacientes portadoras de cistite intersticial e de incontinência urinária de esforço genuína. Casuística e métodos: o perfil e expressão gênica de glicosaminoglicanos no tecido, e o perfil dos glicosaminoglicanos da urina de 11 pacientes com cistite intersticial foram comparados aos de 11 pacientes com incontinência urinária de esforço. A análise estatística foi feita através de teste T e Anova, considerando significativos valores p<0,05. Resultados: verificamos que pacientes com cistite intersticial excretam menor concentração de glicosaminoglicanos na urina do que as portadoras de incontinência urinária de esforço (0,45 ± 0,11 x 0,62 ± 0,13 g/mg creatinina, p<0,05), porém sem redução do conteúdo de glicosaminoglicanos no urotélio. Na imunofluorescência o urotélio de pacientes com cistite intersticial mostrou maior marcação de TGF-beta, decorim (um proteoglicano de condroitim/dermatam sulfato), fibronectina e de ácido hialurônico. Foi identificada menor expressão gênica (PCR em tempo real) das sintases e uma hialuronidase do ácido hialurônico no urotélio das cistites intersticiais. Conclusão: a combinação desses resultados sugere que os glicosaminoglicanos podem estar relacionados ao processo contínuo de inflamação e remodelamento do urotélio disfuncional presente na cistite intersticial. O estudo da expressão gênica pode representar uma altenativa para o entendimento da doença. / Introduction: interstitial cystitis is a chronic disease of the lower urinary tract whose symptoms are: increased urinary frequency, nocturia, perineal or pelvic pain that worses with bladder filling and improves with urination. The pathogenesis is not fully known, but there is evidence that proteoglycans and glycosaminoglycans lining the bladder urothelium can participate in its genesis. The loss of these protective compounds facilitate the contact of ions and solutes in the urine with deeper portions of bladder wall triggering and perpetuating a local inflammatory process. We investigated GAG behavior in urine and tissue (biopsy of bladder urothelium) of patients with IC/PBS and genuine stress urinary incontinence (SUI) in an attempt to better understand its metabolism. Patients and Methods: gene expression and glycosaminoglycans profile in tissue, and glycosaminoglycans profile in urine of 11 patients with interstitial cystitis were compared to 11 patients with pure urinary stress incontinence. Statistical analysis were performed using t Student test and Anova, considering significant when p<0,05. Results: patients with interstitial cystitis excreted lower concentration of glycosaminoglycans in urine when compared to those with pure urinary stress incontinence (respectively 0.45 + 0.11 x 0.62 + 0.13 mg/mg creatinine, p< 0.05). However, there was no reduction of the content of glycosaminoglycans in the urothelium of both patients. The immunofluorescence study showed that patients with interstitial cystitis had a stronger staining of TGF-beta, decorin (a proteoglycan of chondroitin/dermatan sulfate), fibronectin and hyaluronic acid. We were able to indentify by real-time PCR lower gene expression of hyaluronic acid synthases and hyaluronidase in the urothelium of patients with interstitial cystitis. Conclusion: the results suggest that glycosaminoglycans may be related to the ongoing process of inflammation and remodeling of the dysfunctional urothelium that is present in the interstitial cystitis. The study of the gene expression may represent an alternative to understand the disease

A recent focus in the biomedical engineering field has been on developing models of in-vivo tissue responses to help better predict aortic wall mechanics, through numerical methods and simulation, towards improved prediction of aortic wall rupture. The structural influence of both collagen and elastin, integral components within the aortic wall, has been studied and is largely understood, but the contribution of glycosaminoglycans (GAGs) is still unclear. While it has been suggested that the swelling properties of GAGs may participate in the regulation of residual stresses in the aortic wall, whether or not GAGs affect the mechanical properties of the aortic wall is completely unknown. The present study was divided into two experiments: Experiment 1 (n=9) utilized planar biaxial testing to characterize arterial wall mechanics in native porcine aortas. The results of Experiment 1 highlight: (i) decreased tissue thickness moving distally, away from the heart; (ii) increased stiffness from the ascending aorta to the thoracic descending aorta; (iii) no difference in morphometry or stress-strain behaviour between samples excised from the anterior, posterior, and/or left and right lateral walls. Experiment 2 (n=8) employed identical testing parameters to characterize partial and fully enzymatically GAG-depleted tissue, to determine the influence of this macromolecule on aortic wall mechanics. The results of Experiment 2 highlight: (i) GAG content in the porcine aorta does not affect tissue mechanical properties measured from biaxial testing; (ii) enzymatic removal of GAGs does not influence morphometric parameters, including thickness and area. These findings will contribute to improving the fundamental understanding of aortic tissue mechanics by helping to determine the relationship between spatial dependency and mechanical response, and the relationship between individual aortic wall constituents and the overall mechanical behaviour of the aorta.

Polyamides are versatile polymers and includes naturally occurring macromolecules such as proteins as well as purely synthetic materials such as Nylon-3 and Nylon-6 polymers. While there are different ways to prepare polyamides, polyamide synthesis using anionic ring opening polymerization of lactams is the most widely used technique, due to the ease in preparation, excellent control in molecular weight and availability of wide variety of monomers. Our group reported the preparation of carbohydrate-based polyamides called poly-amido-saccharides (PASs) using anionic ring opening polymerization of sugar b-lactam monomers. The PASs reported so far includes glucose, galactose, altrose and maltose PASs, and functional PASs with n-octyl, carboxylate and amine functionalities. Sulfated or block poly-amido-saccharides on the other hand are unknown. In this thesis, I describe the synthesis of sulfated and block poly-amidosaccharides as well as evaluation of their biomedical applications. Naturally occurring sulfated polysaccharides play important roles in anticoagulation, lubrication of cartilage, and in developmental processes. New glucose-based non-regioselectively and regioselectively sulfated poly-amido-saccharides are prepared by the polymerization of protected glucose b-lactams, followed by post-polymerization modification reactions. All polymers are water soluble, non-cytotoxic, and adopt helical conformations. I evaluated the anticoagulant activity of the sulfated polymers using in vitro, ex vivo, and in vivo methods as well as determined the mechanism of anticoagulation by amidolytic activity inhibition assays. Additionally, I synthesized new block copolymers as block copolymers are used for various applications including latex paints and pressure sensitive adhesives. Specifically, carbohydrate-based amphiphilic polymers are of interest for drug delivery applications, due to favorable properties such as cytocompatibility, low immunogenicity, and longer circulation time. We prepared PAS-based amphiphilic block polymers with varied polymer length, hydrophobic to hydrophilic ratio, and stereochemistry of hydrophilic component. I characterized these amphiphilic polymers by NMR, IR, GPC, DSC, TGA and CD, and they self-assemble in water to form nanostructures as determined by DLS, SEM, and cryo-TEM, and are non-cytotoxic. / 2024-11-16T00:00:00Z

Glycosaminoglycans (GAGs), a large family of complex, unbranched polysaccharides, display a variety of essential physiological functions. The structural complexity of GAGs greatly impedes their availability, thus making it difficult to understand the biological roles of GAGs and structure-property relationships. A method that can access GAGs and their analogs with defined structure at relatively large scales will facilitate our understandings of GAG biological roles and biosynthesis modulation. Cellulose is an abundant and renewable natural polymer. Applications of cellulose and cellulose derivatives have drawn increasing attention in recent decades. Chemical modification is an efficient method to append new functionalities to the cellulose backbones. This dissertation describes chemical modification of cellulose and cellulose derivatives to prepare unsulfated and sulfated GAG analogs. Through these studies, we have also discovered novel chemical reactions to modify cellulose. Systematic study of these novel chemistries is also included in this dissertation. We first demonstrated our preparation of two unsulfated GAG analogs by chemical modification of a commercially available cellulose ester. Cellulose acetate was first brominated, followed by azide displacement to introduce azides as the GAG amine precursors. The resulting 6-N3 cellulose acetate was then saponified to liberate 6-OH groups, followed by subsequent (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation of the liberated primary hydroxyl groups to carboxyl groups. Finally, the azides were reduced to amines using a novel reducing reagent, dithiothreitol (DTT). Alternatively, another process utilized thioacetic acid to reduce azides to a mixture of amine and acetamido groups. Through pursuing these GAG analogs, we applied novel azide reductions by DTT and thioacetic acid that are new to polysaccharide chemistry. We systematically investigated the scope of DTT and thioacetic acid azide reduction chemistry under different conditions, substrates, and functional group tolerance. Selective chlorination is another interesting reaction we discovered in functionalization of cellulose esters. We applied this chlorination reaction to hydroxyethyl cellulose (HEC). We then utilized the chlorinated HEC as a substrate for displacement reactions with different types of model nucleophiles to demonstrate the scope of its utility. Overall, we have designed a novel synthetic route to two unsulfated GAG analogs by chemical modification of cellulose acetate. Through exploration of GAG analogs synthesis, we discovered novel methods to modify polysaccharide and polysaccharide derivatives, including azide reduction chemistry and selective chlorination reactions. Successful synthesis of various types of GAG analogs will have great potential biomedical applications and facilitate structure-activity relationship studies. / Doctor of Philosophy / Polysaccharides are long chains of natural sugars. Glycosaminoglycans (GAGs) are an important class of polysaccharides which have complicated chemical structures and play critical roles in many biological processes, including regulation of cell growth, promotion of cell adhesion, anticoagulation, and wound repair. Current methods to obtain these GAGs and GAG analogs are expensive, lengthy, and limited in capability. Novel methods to access these GAGs and their analogs would be promising and would facilitate understanding of biological activities of GAGs. Cellulose is an abundant polymer on earth and provides structural reinforcement in plant cell walls. Cellulose can be further chemically modified to tailor its physiochemical properties. Cellulose and cellulose derivatives have been widely used in many industries for various applications, such as textiles, plastic films, automotive coatings, and drug formulation. This dissertation focuses on modifying inexpensive, abundant cellulose and its derivatives to GAGs and GAG analogs. We start from the simple plant polysaccharide cellulose and obtain structurally complicated analogs of animal-sourced GAGs and GAG analogs. We reached our goal by designing a carefully crafted synthetic route, finally successfully obtaining two types of novel GAG analogs. During this process, we discovered two useful chemical reactions. We systematically investigated these chemical reactions and demonstrated their utility for polysaccharide chemical modification. These successful chemical syntheses of GAGs and their analogs will accelerate our understanding of their natural functions and have potential biomedical applications. The novel chemical methods we discovered will be helpful in chemical modification of polysaccharides.

Sulfated glycosaminoglycans (GAG) are components of the bone marrow stem cell niche and to a minor extent of mature bone tissue with important functions in regulating stem cell lineage commitment and differentiation. We anticipated that artificial extracellular matrices (aECM) composed of collagen I and synthetically oversulfated GAG derivatives affect preferentially the differentiation of osteoblast-precursor cells and early osteoblasts. A set of gradually sulfated chondroitin sulfate and hyaluronan derivatives was used for the preparation of aECM. All these matrices were analysed with human bone marrow stromal cells to identify the most potent aECM and to determine the influence of the degree and position of sulfate groups and the kind of disaccharide units on the osteogenic differentiation. Oversulfated GAG derivatives with a sulfate group at the C-6 position of the N-acetylglycosamine revealed the most pronounced proosteogenic effect as determined by tissue nonspecific alkaline phosphatase activity and calcium deposition. A subset of the aECM was further analysed with different primary osteoblasts and cell lines reflecting different maturation stages to test whether the effect of sulfated GAG derivatives depends on the maturation status of the cells. It was shown that the proosteogenic effect of aECMwasmost prominent in early osteoblasts. [ABSTRACT FROM AUTHOR]

published_or_final_version / Biochemistry / Doctoral / Doctor of Philosophy

Hyaluronidase 2 (HYAL2) is a GPI-linked protein that is proposed to initiate the degradation of hyaluronan (HA), a major extracellular matrix component of many vertebrate tissues. Hyal2 knockout (KO) mice displayed craniofacial abnormalities and severe preweaning lethality. 54% of the surviving KOs developed a grossly dilated left or right atrium, requiring euthanasia, by 3 months of age. We hypothesize that the absence of HYAL2 leads to the accumulation of HA in organs/tissues where HA is normally abundant resulting in developmental defects and organs dysfunction. Molecular and histological analysis of HYAL2 KO hearts demonstrated extracellular accumulation of high molecular mass (HMM) HA in the heart valves, myocardium, serum and lungs which was associated with severe cardiopulmonary dysfunction. Further, structural and functional analyses of Hyal2 KO mouse hearts using high-frequency ultrasound revealed atrial dilation accompanied by diastolic dysfunction that was evident as early as 4 weeks of age, and progressed with age. Further, 50% of HYAL2 KO mice exhibited a triatrial heart (cor-triatriatum). Histological analyses revealed that the atrial dilation was the result of excess tissue, and did not correlate with the presence of cor triatrium. Hyal2 KO mice were found to have increased numbers of mesenchymal cells at early stages of development, presumably due to the presence of excess HA, that lead to cardiac dysfunction. Further examination of HYAL2 distribution in a broad range of mouse tissues, and accumulation of HA in its absence demonstrated that HYAL2 is mainly localized to endothelial cells and some specialized epithelial cells, and plays a major role in HMM-HA degradation. These studies demonstrated that HYAL2 is important for HA degradation and organ development. In the longer term, our findings will be valuable for understanding pathologies associated with the disruption of HA catabolism, and potentially in the identification of HYAL2-deficient patients. / May 2016

Glycosaminoglycans (GAGs) are complex biopolymers that play important roles in inflammation, coagulation, angiogenesis, cell adhesion and viral invasion by interacting with several different proteins.1,2 Structurally, GAGs are built up of several different sulfated disaccharide units.3 Specific GAG sequences that uniquely recognize their cognate proteins exist. Such specificity typically arises from the binding of unique sulfation patterns on the linear GAG chain to highly electropositive protein domains. Thus, these highly charged, sulfated biopolymers potentially represent a new class of therapeutics. Yet, the major stumbling block to the development to these agents is their extremely complicated and tedious chemical synthesis. We hypothesized that replacing the saccharide skeleton with an equivalent non-saccharide and readily synthesized organic skeleton would usher in an era of new, GAG-based therapeutics. This challenge has been addressed on two fronts, computational design and chemical synthesis, by focusing on the heparin pentasaccharide-antithrombin system that represents an exhaustively studied model GAG-protein system. With respect to chemical synthesis, a microwave-based synthetic procedure that can rapidly introduce multiple sulfate groups on a poly-hydroxyl substrate within minutes was developed.4 Using this method, the synthesis of a previously designed activator (IAS5), which otherwise proved to be problematic, was successfully completed. Biochemical screening of IAS5 and its analogs revealed that these molecules could activate antithrombin up to 30-fold in comparison to the 300-fold activation by the heparin pentasaccharide. In an effort to develop more potent antithrombin activators, a new method to predict high affinity GAG sequences for a given GAG-binding protein based on combinatorial virtual-library screening was developed.5 This combinatorial virtual-library screening method was applied to a library of 24,576 non-saccharide, sulfated molecules that were created using the structure of IAS5 as a template. Thirty seven‘hits’ that had common structural features were identified from this study. Interestingly, all these ‘hits’ bind to antithrombin similarly and orient the 4 negative charges identical to the corresponding groups in the heparin pentasaccharide. The synthesis of selected targets is currently in progress and several synthetic steps have already been optimized.

Les glycosaminoglycannes : implication dans la régénération tissulaire après ischémie et utilisation de mimétiques comme agents potentialisateurs des progéniteurs endothéliaux humains pour la régénération vasculaire. Contexte scientifique : Les pathologies vasculaires représentent la première cause de décès dans le monde. Parmi elles, l'ischémie chronique des membres inférieurs conduit fréquemment à une amputation du membre et est associé à une forte mortalité. Les thérapies actuelles, incluant un meilleur mode de vie, les traitements prophylactiques et les interventions chirurgicales ne permettent pas de soigner définitivement les patients. Les progéniteurs endothéliaux circulants (PEC) présentent une capacité de prolifération très élevée, forme des vaisseaux in vivo et s'intègre naturellement à des réseaux vasculaires préexistants. C'est pourquoi, ces cellules sont actuellement considérées comme un outil thérapeutique prometteur pour la réparation vasculaire. Cependant, l'utilisation des PEC en clinique est limitée par leur rareté dans le sang. De plus, les essais cliniques en thérapie cellulaire ont jusqu'à maintenant démontré des résultats prometteurs mais systématiquement limités dans le temps, à cause d'une faible rétention et d'une mort accrue des cellules après injection. Ceci souligne l'importance d'une meilleure compréhension du microenvironnement dans lequel les cellules thérapeutiques sont injectées. Le microenvironnement est en partie constitué par des glycosaminoglycannes (GAG) sulfatés, tels que les Héparanes Sulfates (HS) ou les Chondroïtines Sulfates (CS). Les GAG interagissent avec des partenaires protéiques afin de structurer et de stabiliser la matrice extracellulaire. Les GAG ont également un rôle fonctionnel puisqu'ils régulent de nombreux processus biologiques grâce à leur capacité d'interaction avec des facteurs liant l'héparine.Objectifs: Les objectifs de cette thèse étaient (1) d'améliorer l'isolement des PEC et d'optimiser leurs fonctionnalités endothéliales in vitro à l'aide d'un mimétique de GAG, (2) de caractériser d'un point de vue structurel et fonctionnel les GAG endogènes, et en particulier les HS et les CS, dans le muscle ischémié.Résultats: (1) Nous avons démontrés que l'ajout d'un mimétique de GAG, et plus précisément le composé [OTR4131], pendant les phases d'isolement des PEC à partir du sang de cordon induisait un enrichissement par 4 du nombre de colonies. De plus, l'ajout de ce mimétique dans le milieu de culture permet d'optimiser l'adhérence, la prolifération, la migration ainsi que l'auto-renouvellement des PEC. (2) L'ischémie induit une modification de l'expression des gènes de biosynthèse des GAG, conduisant à des modifications structurelles distinctes des HS et CS. Ces modifications sont corrélées avec des changements dans la capacité des GAG à lier certains facteurs et à moduler l'activité cellulaire. De plus, les CS forment une marque cicatricielle après ischémie.Conclusion & Perspectives: (1) Le mimétique de GAG [OTR4131] devrait permettre d'optimiser les capacités d'expansion des PEC et leurs propriétés endothéliales pour une application thérapeutique. (2) Un intense remodelage des GAG suit l'accident ischémique et perturbe l'activité des facteurs de croissance. Le contrôle des CS constitue une nouvelle approche thérapeutique pour le traitement des lésions du muscle squelettique.Mots-clés : angiogenèse, progéniteurs endothéliaux circulants, glycosaminoglycannes, facteurs liant l'héparine, ischémie, régénération musculaire, réparation vasculaire / Glycosaminoglycans: involvement in tissue regeneration after ischemia and use of mimetic molecules as potentiating agents of human endothelial progenitor cells for vascular regenerationScientific background: Vascular diseases are the leading causes of death in the world. Among them, critical limb ischemia often leads to amputation of the limb and potential mortality. Current therapies including life style management, pharmacological control of risk factors and surgical revascularization do not completely reverse the pathology. Late-outgrowth endothelial colony-forming cells (ECFC) display high proliferative potential, form vessels in vivo and are incorporated into pre-existing vascular networks. Thus, these cells are considered as a promising therapeutic tools for vascular repair. However, the use of ECFC in cell therapy is limited by their rarity in blood. In addition, clinical trials using cell therapy have demonstrated promising results, but there are still a significant problem with poor cell retention and survival. This underlines the relevance to better knowing the microenvironment on which therapeutic cells are transplanted. Microenvironment is in part composed by sulfated glycosaminoglycans (GAG), such as Heparan Sulfate (HS) or Chondroitin Sulfate (CS). GAG interact with proteins to strengthen the structure and stability of the extracellular matrix. GAG have also functional roles since they regulate numerous biological processes through their abilities to interact with heparin-binding growth factors (HBGF).Objectives: The aim of this thesis was (1) to improve production of ECFC and optimize their endothelial properties in vitro using a GAG mimetic molecule, (2) to characterize structurally and functionally endogenous GAG, especially HS and CS species, in ischemic muscle.Results: (1) We demonstrate that the addition of a GAG mimetic molecule, namely the [OTR4131] compound, during the isolation process of ECFC from cord blood induces a 4 fold increase the number of colonies. Moreover, addition of [OTR4131] to cell culture media improves adhesion, proliferation, migration and self-renewal of ECFC. (2) Ischemia induces modifications of expression of GAG biosynthetic enzymes in muscle, leading to changes in HS and CS structures in distinct ways. These changes are correlated with functional modifications of GAG to bind HBGF and to modulate cell activity. Moreover, CS constitute a persistent hallmark of injury after ischemia.Conclusion & Perspectives: (1) The [OTR4131] GAG mimetic should enable optimization of the expansion capacity and the endothelial properties of ECFC for further therapeutic applications. (2) Intense GAG remodeling follows ischemia and disrupts growth factors activities. The control of CS is a promising new therapeutic approach for the treatment of skeletal muscle injury.Keywords: angiogenesis, endothelial progenitor cell, glycosaminoglycans, heparin binding growth factor, ischemia, muscle regeneration, vascular repair

INTRODUÇÃO: As mucopolissacaridoses (MPSs), consideradas doenças de depósito lisossomal, são classificadas, de acordo com a deficiência enzimática, em sete tipos de doenças metabólicas hereditárias de caráter crônico, progressivo e sistêmico. OBJETIVOS: Caracterizar os achados clínicos e avaliar a evolução dos pacientes com diferentes tipos de MPS. MÉTODOS: Trata-se de um estudo retro e prospectivo de 30 pacientes com diferentes tipos de MPSs atendidos na Unidade de Genética do Instituto da Criança do Hospital das Clínicas da Universidade de São Paulo. Para a realização do estudo foi elaborado um protocolo de pesquisa, que compreendeu de uma avaliação clínica e laboratorial. RESULTADOS: Foram estudados 30 pacientes, assim distribuídos: seis MPS I, dois MPS II, sete MPS III, sete MPS IV, seis MPS VI e dois MPS VII. Dezesseis pacientes eram femininos e 14 masculinos. A idade variou entre 2 anos e 22 anos e 4 meses, média de 12 anos e 1 mês. As complicações clínicas detectadas foram: cardiopatia (90%), opacidade de córneas (70%), infecções de repetição (63%), síndrome da apnéia noturna do sono (SAOS) (37%), diarréia (33%), convulsão (17%) e hipertensão artéria sistêmica (HAS) (10%). Cinqüenta por cento dos pacientes foram internados em enfermaria e 13% em UTI, sendo que a s infecções respiratórias foram os principais motivos para as internações hospitalares. O uso do CPAP foi necessário em quatro pacientes, a média de idade para iniciar o uso foi 9 anos e 3 meses. Vinte pacientes foram operados e submetidos a 37 procedimentos anestésicos e 46 procedimentos cirúrgicos (média de 2,3 cirurgia/paciente), sendo que quatro pacientes apresentaram intercorrências: dificuldade de intubação (3), HAS (1) e sangramento (1). A obstrução das vias aéreas superiores e a complicação cardíaca resultaram no óbito de dois pacientes: um MPS I, aos 8 anos e 9 meses, e um com MPS II, aos 12 anos. Quanto aos exames laboratoriais, o teste de toluidina apresentou resultados falsonegativos em 44%, a dosagem de glicosaminoglicanos (GAGs) urinários foi aumentada em todos os pacientes, a cromatografia de GAGs foi normal em quatro pacientes com MPS IV e dosagem enzimática definiu o diagnóstico e o tipo de MPS. Em relação aos outros exames, as alterações radiológicas, disostose múltipla, foram detectadas em 100% dos pacientes, 90% apresentaram achados ecocardigráficos, 27% SAOS de grau acentuado na polissonografia e 57% ventriculomegalia na tomografia computadorizada de crânio. CONCLUSÃO: Os pacientes necessitam de um acompanhamento periódico, por meio de uma equipe multidisciplinar, com o objetivo de se estabelecer um manejo adequado das freqüentes complicações clinicas / INTRODUCTION: mucopolysaccharidoses (MPSs) are a group of lysosomal storage disorders classified, according to specific enzyme deficiency, into seven types of hereditary metabolic diseases of chronic, progressive, and systemic character. OBJECTIVES: to characterize clinical findings and to evaluate the evolution of patients with different types of MPSs seen at the Genetics Division of the Children\'s Hospital of the University of Sao Paulo Clinical Hospital. For the present study, we devised a research protocol including clinical evaluation and laboratory tests. RESULTS: we studied 30 patients, including six MPS I, two MPS II, seven MPS III, seven MPS IV, six MPS VI, and two MPS VII. Sixteen patients were female, and 14 male. Age ranged between 2 years and 22 years and 4 months, mean 12 years and 1 month. Clinical complications detected included: cardiopathy (90%), corneal opacity (70%), recurrent infections (63%), sleep apnea syndrome (SAS) (37%), diarrhea (33%), seizures (17%), and systemic arterial hypertension (SAH) (10%). Fifty percent of patients were admitted to regular wards, and 13% to intensive care units, respiratory infections being the most frequent reason for hospital admission. CPAP was required for four patients; mean age for onset of CPAP use was 9 years and 3 months. Twenty patients underwent surgery, leading to a total 37 anesthetic procedures and 46 surgical procedures (mean 2.3 surgeries/patient); four patients had complications during surgery; these included intubation difficulties (3), SAH (1), and bleeding (1). Obstruction of the upper airways and cardiac complications led to the death of two patients, one MPS I (age 8 years and 9 months) and one MPS II (age 12 years). Regarding laboratory tests, toluidine blue staining showed false-negative results in 44% of patients, urine glycosaminoglycan (GAG) levels were increased in all patients, GAG chromatography was normal in four patients with MPS IV, and enzyme quantification defined the diagnosis and type of MPS. Radiological alterations (multiple dysostosis) were detected in all patients; 90% of patients showed echocardiographic alterations; polysomnography showed marked SAS in 27% of patients; and cranial CAT scans showed ventriculomegaly in 57% of patients. CONCLUSION: MPS patients require regular follow-up by a multidisciplinary team in order to achieve adequate management of frequent clinical complications