Diode laser treatment of pre-threshold and threshold retinopathy of prematurity

Purpose: Retinopathy of prematurity (ROP) is a sight-threatening condition of premature infants. This study aimed to investigate the efficacy of diode laser photocoagulation in the treatment of pre-threshold and threshold ROP. Methods: A retrospective review was conducted of patients who underwent diode laser treatment for ROP by one author (GAG) from 1992 to 2000. During this time, 2137 babies

Panoptic versus conventional ophthalmoscope

Background: The 'ease of use' andaccuracy in measurement of the vertical optic cup/discratio (VCDR) was compared between the conventional direct ophthalmoscope(CO) and Panoptic direct ophthalmoscope (PO) in a group of 'naive' firstyear medical students to determine which would be more suitablefor non-ophthalmologists. Methods: In this quasi-randomized method comparison study,eight students received an introductory session on ophthalmoscopythen examined 18 eyes (9 left, 9 right) with each ophthalmoscopein a private practice. The subjects were the eight students themselvesplus two other subjects. Each subject (n = 10)had one eye dilated. Students determined a VCDR and a subjectivescore of 'ease of use' on a scale of 1 (difficult)to 10 (easy). A consultant ophthalmologist (GAG) determined thebenchmark VCDR for each eye with each ophthalmoscope. Results: Of 288 eye examinations, there were 111 measure-ments of VCDR using the CO (47 undilated, 64dilated), and 140 measurements using the PO (75 undilated, 65 dilated).Differences in the students' estimated VCDR and the benchmarkwere similar for the CO and PO (P = 0.67). 'Easeof use' was scored in 288 eyes and the median score washigher in the PO overall (CO: median 8, IQR 6-9; PO median9, IQR 8-10; P < 0.0001), andwithin each session (P < 0.0001 foreach session). Conclusions: Medical students found the PO mucheasier to use, with accuracy of rating the VCDR similar to the CO. Thiscomparison would support the wider use of the PO amongst medicalstudents, general practitioners and other primary care providers.

Common E protein determinants for attenuation of glycosaminoglycan-binding variants of Japanese encephalitis and West Nile viruses

Natural isolates and laboratory strains of West Nile virus (WNV) and Japanese encephalitis virus (JEV) were attenuated for neuroinvasiveness in mouse models for flavivirus encephalitis by serial passage in human adenocarcinoma (SW13) cells. The passage variants displayed a small-plaque phenotype, augmented affinity for heparin-Sepharose, and a marked increase in specific infectivity for SW13 cells relative to the respective parental viruses, while the specific infectivity for Vero cells was not altered. Therefore, host cell adaptation of passage variants was most likely a consequence of altered receptor usage for virus attachment-entry with the involvement of cell surface glycosaminoglycans (GAG) in this process. In vivo blood clearance kinetics of the passage variants was markedly faster and viremia was reduced relative to the parental viruses, suggesting that affinity for GAG (ubiquitously present on cell surfaces and extracellular matrices) is a key determinant for the neuroinvasiveness of encephalitic flaviviruses. A difference in pathogenesis between WNV and JEV, which was reflected in more efficient growth in the spleen and liver of the WNV parent and passage variants, accounted for a less pronounced loss of neuroinvasiveness of GAG binding variants of WNV than JEV. Single gain-of-net-positive-charge amino acid changes at E protein residue 49, 138, 306, or 389/390, putatively positioned in two clusters on the virion surface, define molecular determinants for GAG binding and concomitant virulence attenuation that are shared by the JEV serotype flaviviruses.

Arthritic disease suppression and cartilage protection with glycosaminoglycan polypeptide complexes (Peptacans) derived from the cartilage extracellular matrix: A novel approach to therapy

Molecular fragments of cartilage are antigenic and can stimulate an autoimmune response. Oral administration of type II collagen prevents disease onset in animal models of arthritis but the effects of other matrix components have not been reported. We evaluated glycosaminoglycan polypeptides (GAG-P) and matrix proteins (CaP) from cartilage for a) mitigating disease activity in rats with collagen-induced arthritis (CIA) and adjuvant-induced arthritis (AIA) and b) stimulating proteoglycan (PG) synthesis by chondrocytes in-vitro. CIA and AIA were established in Wistar rats using standard methods. Agents were administered orally (10–200 mg/kg), either for seven days prior to disease induction (toleragenic protocol), or continuously for 15 days after injecting the arthritigen (prophylactic protocol). Joint swelling and arthritis scores were determined on day 15. Histological sections of joint tissues were assessed post-necropsy. In chondrocyte cultures, CaP + / − interleukin-1 stimulated PG biosynthesis. CaP was also active in preventing arthritis onset at 3.3, 10 or 20 mg/kg in the rat CIA model using the toleragenic protocol. It was only active at 20 and 200 mg/kg in the CIA prophylactic protocol. GAG-P was active in the CIA toleragenic protocol at 20 mg/kg but chondroitin sulfate and glucosamine hydrochloride or glucosamine sulfate were all inactive. The efficacy of CaP in the rat AIA model was less than in the CIA model. These findings lead us to suggest that oral CaP could be used as a disease-modifying anti-arthritic drug.

Articular cartilage glycosaminoglycans inhibit the adhesion of endothelial cells

Articular cartilage undergoes severe loss of proteoglycan and its constituent glycosaminoglycans (GAGs) in osteoarthritis. We hypothesize that the low GAG content of osteoarthritic cartilage renders the tissue susceptible to pathological vascularization. This was investigated using an in vitro angiogenesis model assessing endothelial cell adhesion to GAG-depleted cartilage explants. Bovine cartilage explants were treated with hyaluronidase to deplete GAG content and then seeded with fluorescently tagged human endothelial cells (HMEC-1). HMEC-1 adherence was assessed after 4 hr and 7 days. The effect of hyaluronidase treatment on GAG content, chondrocyte viability, and biochemical composition of the extracellular matrix was also determined. Hyaluronidase treatment reduced the GAG content of cartilage explants by 78 ± 3% compared with that of controls (p <0.0001). GAG depletion was associated with significantly more HMEC-1 adherence on both the surface (superficial zone) and the underside (deep zone) of the explants (both p <0.0001). The latter provided a more favorable environment for extended culture of HMEC-1 compared with the articulating surface. Hyaluronidase treatment altered the immunostaining for chondroitin sulfate epitopes, but not for lubricin. Our results support the hypothesis that articular cartilage GAGs are antiadhesive to endothelial cells and suggest that chondroitin sulfate and/or hyaluronan are responsible. The loss of these GAGs in osteoarthritis may allow osteochondral angiogenesis resulting in disease progression.

A copper-hydrogen peroxide redox system induces dityrosine cross-links and chemokine oligomerisation

The activity of the chemoattractant cytokines, the chemokines, in vivo is enhanced by oligomerisation and aggregation on glycosaminoglycan (GAG), particularly heparan sulphate, side chains of proteoglycans. The chemokine RANTES (CCL5) is a T-lymphocyte and monocyte chemoattractant, which has a minimum tetrameric structure for in vivo activity and a propensity to form higher order oligomers. RANTES is unusual among the chemokines in having five tyrosine residues, an amino acid susceptible to oxidative cross-linking. Using fluorescence emission spectroscopy, Western blot analysis and LCMS-MS, we show that a copper/H2O2 redox system induces the formation of covalent dityrosine cross-links and RANTES oligomerisation with the formation of tetramers, as well as higher order oligomers. Amongst the transition metals tested, namely copper, nickel, mercury, iron and zinc, copper appeared unique in this respect. At high (400 µM) concentrations of H2O2, RANTES monomers, dimers and oligomers are destroyed, but heparan sulphate protects the chemokine from oxidative damage, promoting dityrosine cross-links and multimer formation under oxidative conditions. Low levels of dityrosine cross-links were detected in copper/H2O2-treated IL-8 (CXCL8), which has one tyrosine residue, and none were detected in ENA-78 (CXCL5), which has none. Redox-treated RANTES was fully functional in Boyden chamber assays of T-cell migration and receptor usage on activated T-cells following RANTES oligomerisation was not altered. Our results point to a protective, anti-oxidant, role for heparan sulphate and a previously unrecognised role for copper in chemokine oligomerisation that may offer an explanation for the known anti-inflammatory effect of copper-chelators such as penicillamine and tobramycin.

Determinants of human immunodeficiency virus type 1 escape from the primary CD8+ cytotoxic T lymphocyte response

CD8+ cytotoxic T lymphocytes (CTLs) play an important role in containment of virus replication in primary human immunodeficiency virus (HIV) infection. HIV's ability to mutate to escape from CTL pressure is increasingly recognized; but comprehensive studies of escape from the CD8 T cell response in primary HIV infection are currently lacking. Here, we have fully characterized the primary CTL response to autologous virus Env, Gag, and Tat proteins in three patients, and investigated the extent, kinetics, and mechanisms of viral escape from epitope-specific components of the response. In all three individuals, we observed variation beginning within weeks of infection at epitope-containing sites in the viral quasispecies, which conferred escape by mechanisms including altered peptide presentation/recognition and altered antigen processing. The number of epitope-containing regions exhibiting evidence of early CTL escape ranged from 1 out of 21 in a subject who controlled viral replication effectively to 5 out of 7 in a subject who did not. Evaluation of the extent and kinetics of HIV-1 escape from >40 different epitope-specific CD8 T cell responses enabled analysis of factors determining escape and suggested that escape is restricted by costs to intrinsic viral fitness and by broad, codominant distribution of CTL-mediated pressure on viral replication.

An in vitro comparison of the incorporation, growth, and chondrogenic potential of human bone marrow versus adipose tissue mesenchymal stem cells in clinically relevant cell scaffolds used for cartilage repair

Aim. To compare the incorporation, growth, and chondrogenic potential of bone marrow (BM) and adipose tissue (AT) mesenchymal stem cells (MSCs) in scaffolds used for cartilage repair. Methods. Human BM and AT MSCs were isolated, culture expanded, and characterised using standard protocols, then seeded into 2 different scaffolds, Chondro-Gide or Alpha Chondro Shield. Cell adhesion, incorporation, and viable cell growth were assessed microscopically and following calcein AM/ethidium homodimer (Live/Dead) staining. Cell-seeded scaffolds were treated with chondrogenic inducers for 28 days. Extracellular matrix deposition and soluble glycosaminoglycan (GAG) release into the culture medium was measured at day 28 by histology/immunohistochemistry and dimethylmethylene blue assay, respectively. Results. A greater number of viable MSCs from either source adhered and incorporated into Chondro-Gide than into Alpha Chondro Shield. In both cell scaffolds, this incorporation represented less than 2% of the cells that were seeded. There was a marked proliferation of BM MSCs, but not AT MSCs, in Chondro-Gide. MSCs from both sources underwent chondrogenic differentiation following induction. However, cartilaginous extracellular matrix deposition was most marked in Chondro- Gide seeded with BM MSCs. Soluble GAG secretion increased in chondrogenic versus control conditions. There was no marked difference in GAG secretion by MSCs from either cell source. Conclusion. Chondro-Gide and Alpha Chondro Shield were permissive to the incorporation and chondrogenic differentiation of human BM and AT MSCs. Chondro-Gide seeded with BM MSCs demonstrated the greatest increase in MSC number and deposition of a cartilaginous tissue.

Um dermatam sulfato antitrombótico do camarão Litopenaeus vanammei inibe a inflamação e angiogênese

Inflammation is combined of a vascular and a cellular reaction, resulting in different cells and tissue responses, both the intravascular and extravascular environment. As the inflammatory process occurs, coagulation proteases, in particular thrombin (FIIa), are able to initiate various cellular responses in vascular biology and therefore is often observed activation of other biological systems, leading to complications during an event inflammatory, such as thrombosis and angiogenesis. Thus, antagonists molecules of these events are interesting models for the development of novel anti-inflammatory drugs. Thereby, it is worth stressing the glycosaminoglycans (GAGs), which are able to interact with several proteins involved in important biological processes, including inflammation and coagulation. Therefore, this study aimed to evaluate the anti-inflammatory, antithrombotic and anti-angiogenic potentials, as well anticoagulant of a dermatan sulfate-like GAG (DS) extracted from the Litopenaeus vannamei cephalotorax. The compound was obtained after proteolysis and purification by ion-exchange chromatography. After total digestion by DS-like compounds digesting lyases (chondroitinase ABC), the DS-like nature was revealed, and then called DSL. The shrimp compound showed reduced anticoagulant effect by the aPTT assay, but high anti-IIa activity, directly and through heparin cofactor II. On inflammation, the compound had a significant inhibitory effect with the reduction of proinflammatory cytokines. Potential Inhibitory were reported in the antithrombotic and anti-angiogenic assay, the latter being dose dependent. As for anti-hemostatic activity, the polysaccharides did not induced significant bleeding effect. Thus, the results shown by the shrimp DS-like compound indicate this glycosaminoglycan as a biotechnology target with prospects for the development of new multipotent drugs.

Études de la pathogénèse du VIH chez différents modèles murins

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Études de la pathogénèse du VIH chez différents modèles murins

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Histochemical studies of chondrogenesis

The formation of the cartilage tissue depends on the coordination of cell to cell or cell to ECM interaction that cause to the cell polarity, migration and differentiation of precursor mesenchymal cells during chondrogenesis Many of these events are mediated by ECM components such as glycocojugates which with their suger residues such as galactose or aminosuger have a ligand role for regulatory molecules. The aim of this study was to identify the presence and distribution of some different glycoconjugates and their suger residues in the chondrogenesis by histochemistry and lectin-histochemistry techniques. For this purpose, embryos from pregnant wistar rats from E12-E20 were collected and fixed. Some of them were stained with alizarin red Salcin blue staining to demonstrate cartilage and bone formation in whole mount embryos. Other embryos with serial sections (5-7micm thikness) were stained by: 1-alcian blue (pH: l) for S-GAG,2-alcin blue (pH:2.5)for C-GAG, S-PAS alcian blue fora neutral and acidic sugers,4- tuloidin blue for metachromatic substances. Stained sections were graded according to the staining intensity (0-5 grading s method). Statistical analysis showed significant difference for those substances among experimental groups. Lectin histochemistry with MPA, VVA, SBA, OFA demonstrated differences between organs for suger residues during chondrogensis. It seems that synthesis and secretion of glycocojugates and change of their suger residues follows a spatiotemporal pattern and developmentaly regulated.

Effects of sodium hyaluronate and triamcinolone acetonide on proteoglycan metabolism in equine articular chondrocytes treated with interleukin-1

The objective of this study is to determine if the effects of a high molecular weight sodium hyaluronate (HA) alone or in combination with triamcinolone acetate (TA) can mitigate chondrocyte proteoglycan catabolism caused by interleukin-1 (IL-1) administration. Chondrocytes were collected from fetlock joints of ten horses euthanized for reasons unrelated to joint disease. Chondrocyte pellets were treated with media (negative control); media containing IL-1 only (positive control); or media containing IL-1 with HA only (0.5 or 2.0 mg/mL), TA only (0.06 or 0.6 mg/mL), or HA (0.5 or 2.0 mg/mL) and TA (0.06 or 0.6 mg/mL) in combination. Chondrocyte pellets were assayed for newly synthesized GAG, total GAG content, total DNA content, and mRNA levels of collagen type II, aggrecan, and COX-2. The high concentration of HA (2.0 mg/mL) increased GAG synthesis while the high concentration of TA (0.6 mg/mL) decreased loss of GAG into the media. Both the high concentration of HA and TA increased the total GAG content within the pellet. There was no change in pellet DNA content with either treatment. TA reduced COX-2 mRNA levels as well as aggrecan and collagen type II expression. Treatment with HA had no effect on mRNA levels of COX-2, aggrecan or collagen type II. These results indicate that the high concentration of HA or TA alone or in combination will mitigate effects of IL-1 administration on proteoglycan catabolism of equine articular chondrocytes.

Interface cena e tecnologia : composições cênicas mediadas

Based on the presupposition that the arts in the West always counted on resources, supports, and devices pertaining to its time context, an reflection is intended regarding the scenic compositions mediated by digital technologies do. Such technologies are inserted in the daily routine, also composing artistic experiments, thus playing a dialogical role with the art/technology intersection. Therefore, the proposal is to investigate what relationships are established in the contemporary theatrical scene from the contagion by digital technologies, aiming at establishing this parallel through a dialogue with the authors discussing the subject, and also based on the group practices having technological resources as a determinant factor in their plays. Furthermore, a reflection should be made on the scene that incorporates or is carried out in intermediatic events, analyzing how digital technologies (re)configure compositional processes of the plays by GAG Phila7, in the city of São Paulo/SP. For such, the dissertation is organized in three sections comprising four moments, to wit: brief overview of the field, contextualization, poetic analysis and synthesis. Qualitative methods are used as the methodological proposal: semi-structure interview, note and document taking (program, website, playing book, disclosure material for advertising text, photographs, and videos). Within the universe of qualitative research, it works with the epistemological perspective of the Gadamer philosophical hermeneutics. The possibilities allowed by the double virtual (Internet/web) generated a type of theater with another material basis and new forms of organization and structure, being possible to perceive that such technological advances and the arts are mutually contaminated, generating a dislocation in the logics of theatrical composition, movement beginning with the artistic vanguards, gradually intensified, thus offering new possibilities of constructions and hybridization of the of the most different possible types. Experiment ―Profanações_superfície de eventos de construção coletiva‖, idealized by Phila7 is inserted in this perspective. Object of the discussion of such research, the experiment works with possible poetics arising from the intersection with the digital technologies, aiming at identifying and problematizing the challenges from the technological evolution and expansion in a scenic context

Revitalização dos saberes e práticas Kaingang sobre as plantas tradicionais como proposta de educação ambiental na terra indígena Ligeiro

O presente trabalho objetiva investigar a Revitalização dos Saberes e Práticas Kaingang Sobre as Plantas Tradicionais como Proposta de Educação Ambiental na comunidade Terra Indígena de Ligeiro no município de Charrua - RS. Trata-se de uma pesquisa de campo que busca melhor compreender o que provocou o abandono e esquecimento desses saberes, bem como possíveis alternativas teóricas e práticas para que a revitalização dos saberes culturais ancestrais seja realizada. Justifica-se pelo fato da utilização de plantas medicinais para o tratamento de enfermidades estar enraizada nas culturas indígenas e poder assim suprir, em parte, a deficiente atenção à saúde e as realidades da fome em muitas T.I. Foram realizadas visitas a campo para análise da situação atual e coleta de informações, com aplicação de entrevistas com vários indígenas, bem como com kujà e curandeiras; se implantou um horto medicinal com várias plantas, ervas e se distribuíram mudas de plantas frutíferas nativas. Para este projeto, dois alunos indígenas do IFRS - Campus Sertão atuaram na implantação deste Horto, assim como outros alunos indígenas da Escola Estadual Indígena de Ensino Médio Fág Mág (Pinheiro Grande) trabalharam e apoiaram na execução dessa ação. Através da realização de fotos e vídeos, foram analisadas também as expressões atuais da cultura Kaingang na conjuntura, os elementos significativos que estão guardados ao longo das gerações e apontamos os desafios de permanecer na comunidade e revitalizar com sustentabilidade os saberes e práticas Kaingang, sempre com um olhar incondicional pela natureza. Foram sistematizadas as denominações específicas da cada planta, em correspondência com seu nome científico e com o seu nome tradicional da cosmologia dual Kaingang (kam e kanhru). Conclui-se a partir dessa investigação que houve efetivamente o abandono e a falta de valorização de saberes e práticas relacionadas com a educação ambiental, pelas pressões da sociedade branca, o desejo de alguns indígenas de ser moderno e aceito na sociedade branca e pela ausência de trabalho de um educador ambiental. As iniciativas de revitalização são possíveis; o uso de plantas e alimentos tradicionais estão relacionadas com atividades que precisam ser vivenciadas primordialmente na escola, na relação com os kujà tradicionais e no desenvolvimento de projetos específicos e na motivação permanente para a responsabilidade ambiental, preservando a cultura e os costumes Kaingang que ainda são preciosos, especialmente na promoção da saúde da comunidade