The Lyndon Baines Johnson Room : Room S-211, United States Capitol /

Shipping list no.: 96-0356-P.

Vollständige englische Sprachlehre für den ersten Unterricht sowohl, als für das tiefere Studium, nach den besten Grammatikern und Orthoepisten: Beattie, Harris, Johnson, Lowth, Murray, Nares, Walker, u.A.,

V.2. Published Leipzig, Hartmann, 1826.

Travels in the footsteps of Bruce in Algeria and Tunis,

Mode of access: Internet.

Esto perpetua: the Club of Dr. Johnson and his friends, 1764-1784,

Bibliographical references included in "Notes" (p. 61-64)

The life of Samuel Johnson, LL.D and the journal of his tour to the Hebrides.

Mode of access: Internet.

Report to the Right Hon. the Lord Chief Baron, and the Hon. the Barons of His Majesty's Court of Exchequer in Scotland, by the King's Remembrancer, relative to the tomb of King Robert the Bruce, and the Cathedral Church of Dunfermline.

Mode of access: Internet.

O LONG ZOOM: PENSAMENTO SISTÊMICO, INTERDISCIPLINARIDADE E COMUNICAÇÃO EM STEVEN JOHNSON

Steven Johnson é uma referência de relevo na pesquisa brasileira sobre comunicação digital. Ainda assim, essa temática é abordada apenas de maneira tangencial na maior parte da sua produção bibliográfica: os livros de Johnson são, ao mesmo tempo, exemplos e defesas de um método de pesquisa e exposição que integra pensamento sistêmico e abordagem interdisciplinar ao qual ele chama long zoom e que tem a pretensão de trazer novos fatos sobre os fenômenos aos quais é aplicado. Essa dissertação, através de um estudo teórico, analisa os limites e as possibilidades do pensamento de Steven Johnson e de seu long zoom para a pesquisa científica em Comunicação Social. Por meio de uma revisão bibliográfica da obra do autor, cruzando-a com dados biográficos, é apresentada uma análise de conjunto do pensamento de Steven Johnson que o caracteriza como, fundamentalmente, um pensamento epistemológico. A partir disso, com uma breve revisão das principais miradas epistemológicas, da Grécia Antiga ao século XXI, são traçados os parentescos intelectuais do long zoom. Num terceiro momento, revisa-se as formas com que Johnson aplica o long zoom aos problemas da Comunicação Social, verificando-se uma tendência dominante a ressaltar as consequências sociais dos fluxos de informação permitidos pelos meios de comunicação TV e internet, sobretudo, mas também videogames numa aproximação com a Cibernética e, principalmente, um modelo mcluhaniano de análise da comunicação. Após esse trajeto, conclui-se que, a despeito das suas próprias pretensões, Johnson não apresenta novos fatos com o seu long zoom, mas novos pontos de vista e proposições teóricas que podem ou não vir a ser comprovadas pelo trabalho de cientistas.

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.

Human intervertebral disc aggrecan inhibits endothelial cell adhesion and cell migration in vitro

STUDY DESIGN: The effect of human intervertebral disc aggrecan on endothelial cell growth was examined using cell culture assays. OBJECTIVE: To determine the response of endothelial cells to human intervertebral disc aggrecan, and whether the amount and type of aggrecan present in the intervertebral disc may be implicated in disc vascularization. SUMMARY OF BACKGROUND DATA: Intervertebral disc degeneration has been associated with a loss of proteoglycan, and the ingrowth of blood vessels and nerves. Neovascularization is a common feature also of disc herniation. Intervertebral disc aggrecan is inhibitory to sensory nerve growth, but the effects of disc aggrecan on endothelial cell growth are not known. METHODS: Aggrecan monomers were isolated separately from the anulus fibrosus and nucleus pulposus of human lumbar intervertebral discs, and characterized to determine the amount and type of sulfated glycosaminoglycan side chains present. The effects of these aggrecan isolates on the cellular adhesion and migration of the human endothelial cell lines, HMEC-1 and EAhy-926, were examined in vitro. RESULTS: Homogenous substrata of disc aggrecan inhibited endothelial cell adhesion and cell spreading in a concentration dependent manner. In substrata choice assays, endothelial cells seeded onto collagen type I migrated over the collagen until they encountered substrata of disc aggrecan, where they either stopped migrating, retreated onto the collagen, or, more commonly, changed direction to align along the collagen-aggrecan border. The inhibitory effect of aggrecan on endothelial cell migration was concentration dependent, and reduced by enzymatic treatment of the aggrecan monomers with a combination of chondroitinase ABC and keratinase/keratinase II. Anulus fibrosus aggrecan was more inhibitory to endothelial cell adhesion than nucleus pulposus aggrecan. However, this difference did not relate to the extent to which the different aggrecan isolates were charged, as determined by colorimetric assay with 1,9-dimethylmethylene blue, or to marked differences in the distribution of chondroitin sulfated and keratan sulfated side chains. CONCLUSIONS: Human intervertebral disc aggrecan is inhibitory to endothelial cell migration, and this inhibitory effect appears to depend, in part, on the presence of glycosaminoglycan side chains on the aggrecan monomer.