807 research outputs found

    Destructive effects of murine arthritogenic antibodies to type II collagen on cartilage explants in vitro

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    Certain monoclonal antibodies (mAbs) to type II collagen (CII) induce arthritis in vivo after passive transfer and have adverse effects on chondrocyte cultures and inhibit self assembly of collagen fibrils in vitro. We have examined whether such mAbs have detrimental effects on pre-existing cartilage. Bovine cartilage explants were cultured over 21 days in the presence of two arthritogenic mAbs to CII (CIIC1 or M2139), a non-arthritogenic mAb to CII (CIIF4) or a control mAb (GAD6). Penetration of cartilage by mAb was determined by immunofluorescence on frozen sections and correlated with changes to the extracellular matrix and chondrocytes by morphometric analysis of sections stained with toluidine blue. The effects of mAbs on matrix components were examined by Fourier transform infrared microspectroscopy (FTIRM). A possible role of Fc-binding was investigated using F(ab)(2 )from CIIC1. All three mAbs to CII penetrated the cartilage explants and CIIC1 and M2139, but not CIIF4, had adverse effects that included proteoglycan loss correlating with mAb penetration, the later development in cultures of an abnormal superficial cellular layer, and an increased proportion of empty chondrons. FTIRM showed depletion and denaturation of CII at the explant surface in the presence of CIIC1 or M2139, which paralleled proteoglycan loss. The effects of F(ab)(2 )were greater than those of intact CIIC1. Our results indicate that mAbs to CII can adversely affect preformed cartilage, and that the specific epitope on CII recognised by the mAb determines both arthritogenicity in vivo and adverse effects in vitro. We conclude that antibodies to CII can have pathogenic effects that are independent of inflammatory mediators or Fc-binding

    Implanting Loop Recorders in a Hospital Unit versus the Electrophysiology Laboratory: A Retrospective Chart Review

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    Introduction: Cardiac arrhythmias and unexplained syncopal episodes remain a challenge for clinicians to diagnose. The recent creation of the smallest Implantable Loop Recorder (ILR) assists in identifying the causes behind cardiac and neurological events. The current study aimed to compare the practice of implanting loop recorders at the bedside in the Cardiac and Vascular Care Unit (CVCU) to implantations in the Electrophysiology Laboratory (EP Lab). Methods: This study was a retrospective review of electronic medical records. Data abstraction included implantation dates, time of admission and discharge, length of stay (LOS), number of healthcare staff involved, and cost of the procedure. Results: Over ten months, 63 ILRs were implanted in the EP Lab and 131 ILRs at the bedside. Patients LOS, on average, in the EP Lab was five hours versus four hours at the bedside. Five staff were required to implant the ILR in the EP Lab, and two at the bedside. Based on 63 cases in the EP Lab, the hospital generated revenue of 395,640,whereasthe131casesatthebedsidegeneratedrevenueof395,640, whereas the 131 cases at the bedside generated revenue of 822,680. This resulted in an increase in revenue of $427,040. Discussion: A higher number of procedures were done at the bedside leading to a decreased average length of stay, number of staff involved, cost of the procedure, and a reduction in waiting time for patient admission and discharge

    A Gradient-Based Implicit Blend

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    International audienceWe introduce a new family of binary composition operators that solves four major problems of constructive implicit modeling: suppressing bulges when two shapes merge, avoiding unwanted blending at a distance, ensuring that the resulting shape keeps the topology of the union, and enabling sharp details to be added without being blown up. The key idea is that field functions should not only be combined based on their values, but also on their gradients.We implement this idea through a family of C1 composition operators evaluated on the GPU for efficiency, and illustrate it by applications to constructive modeling and animation

    Molecular Hydrogen in the FUSE Translucent Lines of Sight: The Full Sample

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    We report total abundances and related parameters for the full sample of the FUSE survey of molecular hydrogen in 38 translucent lines of sight. New results are presented for the "second half" of the survey involving 15 lines of sight to supplement data for the first 23 lines of sight already published. We assess the correlations between molecular hydrogen and various extinction parameters in the full sample, which covers a broader range of conditions than the initial sample. In particular, we are now able to confirm that many, but not all, lines of sight with shallow far-UV extinction curves and large values of the total-to-selective extinction ratio, RVR_V = AVA_V / E(B−V)E(B-V) -- characteristic of larger than average dust grains -- are associated with particularly low hydrogen molecular fractions (fH2f_{\rm H2}). In the lines of sight with large RVR_V, there is in fact a wide range in molecular fractions, despite the expectation that the larger grains should lead to less H2_2 formation. However, we see specific evidence that the molecular fractions in this sub-sample are inversely related to the estimated strength of the UV radiation field and thus the latter factor is more important in this regime. We have provided an update to previous values of the gas-to-dust ratio, NN(Htot_{\rm tot})/E(B−V)E(B-V), based on direct measurements of NN(H2_2) and NN(H I). Although our value is nearly identical to that found with Copernicus data, it extends the relationship by a factor of 2 in reddening. Finally, as the new lines of sight generally show low to moderate molecular fractions, we still find little evidence for single monolithic "translucent clouds" with fH2f_{\rm H2} ∌\sim 1.Comment: 35 pages, 5 tables, 7 figures, accepted for publication in The Astrophysical Journal Supplements Serie

    Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study

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    Distinct diurnal and seasonal variations of mercury (Hg) have been observed in near-surface air at Concordia Station on the East Antarctic Plateau, but the processes controlling these characteristics are not well understood. Here, we use a box model to interpret the Hg0 (gaseous elemental mercury) measurements in thes year 2013. The model includes atmospheric Hg0 oxidation (by OH, O3, or bromine), surface snow HgII (oxidized mercury) reduction, and air-snow exchange, and is driven by meteorological fields from a regional climate model. The simulations suggest that a photochemically driven mercury diurnal cycle occurs at the air-snow interface in austral summer. The fast oxidation of Hg0 in summer may be provided by a two-step bromine-initiated scheme, which is favored by low temperature and high nitrogen oxides at Concordia. The summertime diurnal variations of Hg0 (peaking during daytime) may be confined within several tens of meters above the snow surface and affected by changing mixed layer depths. Snow re-emission of Hg0 is mainly driven by photoreduction of snow HgII in summer. Intermittent warming events and a hypothesized reduction of HgII occurring in snow in the dark may be important processes controlling the mercury variations in the non-summer period, although their relative importance is uncertain. The Br-initiated oxidation of Hg0 is expected to be slower at Summit Station in Greenland than at Concordia (due to their difference in temperature and levels of nitrogen oxides and ozone), which may contribute to the observed differences in the summertime diurnal variations of Hg0 between these two polar inland stations.National Science Foundation (U.S.) (Grant ACP-1053648

    Consumo de nutrientes de dietas contendo diferentes nĂ­veis de farelo de melancia forrageira (Citrullus lanatus cv. Citroides), em ovinos.

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    Utilizou-se 20 cordeiros, com idade média de seis meses e peso vivo médio de 11,2 kg (+- 1,2), submetidos a um delineamento experimental inteiramente casuaiizado, para determinar os consumos de matéria seca (MS), matéria orgùnica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN) e carboidratos totais (CHOT). Cinco dietas contendo D1:80; D2:65; D3:50; D4:35 e D5:20% de farelo de melancia como conncentrado e feno de guandu taipeiro como volumoso, foram avaliadas. As anålises estatísticas das variåveis estudadas foram interpretadas por anålises de variùncia e de regressão os consumos de MS, MO, PB, CHOT e FDN, expressos em g/dia, apresentaram um comportamento quadråtico (P<0,05) com o aumento do nível de farelo de melancia nas dietas, enquanto o consumo de EE não foi alterado. As diferentes proporçÔes de farelo de melancia e feno de guandu taipeiro, utilizadas nas dietas não proporcionaram um consumo de nutrientes adequado para ovinos

    Uso do farelo de melancia forrageira (Citrullus lanatus cv. Citroides) e do feno de guandu (Cajanus cajan (L.) Millspaugh cv. D1 Type.), em dietas para ovinos: digestibilidade de nutrientes.

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    Para se determinarem os coeficientes de digestibilidade da matĂ©ria seca (MS), matĂ©ria (MO), proteĂ­na bruta (PB), extrato etĂ©reo (EE), fibra em detergente neutro (FDN) e carboidratos totais (CHOT), foi realizado um ensaio de digestibilidade, utilizando-se cinco dietas contendo D1:80; D2:65; D3:50; 1)4:35 e D5:20% de farelo de melancia como concentrado e feno de guandu taipeiro como volumoso. Vinte cordeiros mestiços, com idade mĂ©dia de seis meses e peso vivo mĂ©dio de 11,2 kg (+-1,2), foram submetidos a um delineamento inteiramente casualizado, com cinco tratamentos e quatro repetiçÔes. O nĂ­vel de farelo de melancia forrageira na dieta influenciou linearmente a digestibilidade aparente da MO (62 a 54%) e dos CHOT (58 a 47%). A digestibilidade da PB teve um comportamento cĂșbico. Os nĂ­veis de concentrado nĂŁo influenciaram a digestibilidade da MS, FDN e do EE. Pode-se concluir que os coeficientes de digestibilidade dos nutrientes das dietas, foram satisfatĂłrios e prĂłximos aos valores encontrados para algumas dietas e forrageiras utilizadas para ovinos, no semi-ĂĄrido nordestino
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