9 research outputs found
Proteomic, biomechanical and functional analyses define neutrophil heterogeneity in systemic lupus erythematosus
Funder: NHLI FoundationFunder: NIHR Imperial Biomedical Research Centre; FundRef: http://dx.doi.org/10.13039/501100013342Funder: National Heart Lung and Blood InstituteFunder: Medical Research Council; FundRef: http://dx.doi.org/10.13039/501100000265Funder: National Institute of Biomedical Imaging and Bioengineering; FundRef: http://dx.doi.org/10.13039/100000070Funder: Gates Cambridge ScholarshipFunder: NIH/OXCAM FellowshipObjectives: Low-density granulocytes (LDGs) are a distinct subset of proinflammatory and vasculopathic neutrophils expanded in systemic lupus erythematosus (SLE). Neutrophil trafficking and immune function are intimately linked to cellular biophysical properties. This study used proteomic, biomechanical and functional analyses to further define neutrophil heterogeneity in the context of SLE. Methods: Proteomic/phosphoproteomic analyses were performed in healthy control (HC) normal density neutrophils (NDNs), SLE NDNs and autologous SLE LDGs. The biophysical properties of these neutrophil subsets were analysed by real-time deformability cytometry and lattice light-sheet microscopy. A two-dimensional endothelial flow system and a three-dimensional microfluidic microvasculature mimetic (MMM) were used to decouple the contributions of cell surface mediators and biophysical properties to neutrophil trafficking, respectively. Results: Proteomic and phosphoproteomic differences were detected between HC and SLE neutrophils and between SLE NDNs and LDGs. Increased abundance of type 1 interferon-regulated proteins and differential phosphorylation of proteins associated with cytoskeletal organisation were identified in SLE LDGs relative to SLE NDNs. The cell surface of SLE LDGs was rougher than in SLE and HC NDNs, suggesting membrane perturbances. While SLE LDGs did not display increased binding to endothelial cells in the two-dimensional assay, they were increasingly retained/trapped in the narrow channels of the lung MMM. Conclusions: Modulation of the neutrophil proteome and distinct changes in biophysical properties are observed alongside differences in neutrophil trafficking. SLE LDGs may be increasingly retained in microvasculature networks, which has important pathogenic implications in the context of lupus organ damage and small vessel vasculopathy
183 A phase 1B/2A trial of tofacitinib, an oral janus kinase inhibitor, in systemic lupus erythematosus
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A unified approach to the economic aspects of statistical quality control and improvement
Assignment (MSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: The design of control charts refers to the selection of the parameters implied, including the
sample size n, control limit width parameter k, and the sampling interval h. The design of the
X -control chart that is based on economic as well as statistical considerations is presently one of
the more popular subjects of research. Two assumptions are considered in the development and
use of the economic or economic statistical models. These assumptions are potentially critical. It
is assumed that the time between process shifts can be modelled by means of the exponential
distribution. It is further assumed that there is only one assignable cause. Based on these
assumptions, economic or economic statistical models are derived using a total cost function per
unit time as proposed by a unified approach of the Lorenzen and Vance model (1986). In this
approach the relationship between the three control chart parameters as well as the three types of
costs are expressed in the total cost function. The optimal parameters are usually obtained by the
minimization of the expected total cost per unit time. Nevertheless, few practitioners have tried
to optimize the design of their X -control charts. One reason for this is that the cost models and
their associated optimization techniques are often too complex and difficult for practitioners to
understand and apply. However, a user-friendly Excel program has been developed in this paper
and the numerical examples illustrated are executed on this program. The optimization procedure
is easy-to-use, easy-to-understand, and easy-to-access. Moreover, the proposed procedure also
obtains exact optimal design values in contrast to the approximate designs developed by Duncan
(1956) and other subsequent researchers.
Numerical examples are presented of both the economic and the economic statistical designs of
the X -control chart in order to illustrate the working of the proposed Excel optimal procedure.
Based on the Excel optimization procedure, the results of the economic statistical design are
compared to those of a pure economic model. It is shown that the economic statistical designs
lead to wider control limits and smaller sampling intervals than the economic designs.
Furthermore, even if they are more costly than the economic design they do guarantee output of
better quality, while keeping the number of false alarm searches at a minimum. It also leads to
low process variability. These properties are the direct result of the requirement that the
economic statistical design must assure a satisfactory statistical performance.
Additionally, extensive sensitivity studies are performed on the economic and economic
statistical designs to investigate the effect of the input parameters and the effects of varying the bounds on, a, 1-f3 , the average time-to-signal, ATS as well as the expected shift size t5 on
the minimum expected cost loss as well as the three control chart decision variables. The
analyses show that cost is relatively insensitive to improvement in the type I and type II error
rates, but highly sensitive to changes in smaller bounds on ATS as well as extremely sensitive
for smaller shift levels, t5 .
Note: expressions like economic design, economic statistical design, loss cost and assignable
cause may seen linguistically and syntactically strange, but are borrowed from and used
according the known literature on the subject.AFRIKAANSE OPSOMMING: Die ontwerp van kontrolekaarte verwys na die seleksie van die parameters geïmpliseer,
insluitende die steekproefgrootte n , kontrole limiete interval parameter k , en die
steekproefmterval h. Die ontwerp van die X -kontrolekaart, gebaseer op ekonomiese sowel as
statistiese oorwegings, is tans een van die meer populêre onderwerpe van navorsing. Twee
aannames word in ag geneem in die ontwikkeling en gebruik van die ekonomiese en ekonomies
statistiese modelle. Hierdie aannames is potensieel krities. Dit word aanvaar dat die tyd tussen
prosesverskuiwings deur die eksponensiaalverdeling gemodelleer kan word. Daar word ook
verder aangeneem dat daar slegs een oorsaak kan wees vir 'n verskuiwing, of te wel 'n
aanwysbare oorsaak (assignable cause). Gebaseer op hierdie aannames word ekonomies en
ekonomies statistiese modelle afgelei deur gebruik te maak van 'n totale kostefunksie per
tydseenheid soos voorgestel deur deur 'n verenigende (unified) benadering van die Lorenzen en
Vance-model (1986). In hierdie benadering word die verband tussen die drie kontrole
parameters sowel as die drie tipes koste in die totale kostefunksie uiteengesit. Die optimale
parameters word gewoonlik gevind deur die minirnering van die verwagte totale koste per
tydseenheid. Desnieteenstaande het slegs 'n minderheid van praktisyns tot nou toe probeer om
die ontwerp van hulle X -kontrolekaarte te optimeer. Een rede hiervoor is dat die kosternodelle
en hulle geassosieerde optimeringstegnieke té kompleks en moeilik is vir die praktisyns om te
verstaan en toe te pas. 'n Gebruikersvriendelike Excelprogram is egter hier ontwikkel en die
numeriese voorbeelde wat vir illustrasie doeleindes getoon word, is op hierdie program
uitgevoer. Die optimeringsprosedure is maklik om te gebruik, maklik om te verstaan en die
sagteware is geredelik beskikbaar. Wat meer is, is dat die voorgestelde prosedure eksakte
optimale ontwerp waardes bereken in teenstelling tot die benaderde ontwerpe van Duncan (1956)
en navorsers na hom.
Numeriese voorbeelde word verskaf van beide die ekonomiese en ekonomies statistiese
ontwerpe vir die X -kontrolekaart om die werking van die voorgestelde Excel optimale
prosedure te illustreer. Die resultate van die ekonomies statistiese ontwerp word vergelyk met
dié van die suiwer ekomomiese model met behulp van die Excel optimerings-prosedure. Daar
word aangetoon dat die ekonomiese statistiese ontwerpe tot wyer kontrole limiete en kleiner
steekproefmtervalle lei as die ekonomiese ontwerpe. Al lei die ekonomies statistiese ontwerp tot
ietwat hoër koste as die ekonomiese ontwerpe se oplossings, waarborg dit beter kwaliteit terwyl
dit die aantal vals seine tot 'n minimum beperk. Hierbenewens lei dit ook tot kleiner prosesvartasie. Hierdie eienskappe is die direkte resultaat van die vereiste dat die ekonomies
statistiese ontwerp aan sekere statistiese vereistes moet voldoen.
Verder is uitgebreide sensitiwiteitsondersoeke op die ekonomies en ekonomies statistiese
ontwerpe gedoen om die effek van die inset parameters sowel as van variërende grense op a,
1- f3 , die gemiddelde tyd-tot-sein, ATS sowel as die verskuiwingsgrootte 8 op die minimum
verwagte kosteverlies sowel as die drie kontrolekaart besluitnemingsveranderlikes te bepaal. Die
analises toon dat die totale koste relatief onsensitief is tot verbeterings in die tipe I en die tipe II
fout koerse, maar dat dit hoogs sensitief is vir wysigings in die onderste grens op ATS sowel as
besonder sensitief vir klein verskuiwingsvlakke, 8.
Let op: Die uitdrukkings ekonomiese ontwerp (economic design), ekonomies statistiese ontwerp
(economic statistical design), verlies kostefunksie (loss cost function) en aanwysbare oorsaak
(assignable cause) mag taalkundig en sintakties vreemd voordoen, maar is geleen uit, en word so
gebruik in die bekende literatuur oor hierdie onderwerp
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Proteomic, biomechanical and functional analyses define neutrophil heterogeneity in systemic lupus erythematosus
Funder: NHLI FoundationFunder: NIHR Imperial Biomedical Research Centre; FundRef: http://dx.doi.org/10.13039/501100013342Funder: National Heart Lung and Blood InstituteFunder: Medical Research Council; FundRef: http://dx.doi.org/10.13039/501100000265Funder: National Institute of Biomedical Imaging and Bioengineering; FundRef: http://dx.doi.org/10.13039/100000070Funder: Gates Cambridge ScholarshipFunder: NIH/OXCAM FellowshipObjectives: Low-density granulocytes (LDGs) are a distinct subset of proinflammatory and vasculopathic neutrophils expanded in systemic lupus erythematosus (SLE). Neutrophil trafficking and immune function are intimately linked to cellular biophysical properties. This study used proteomic, biomechanical and functional analyses to further define neutrophil heterogeneity in the context of SLE. Methods: Proteomic/phosphoproteomic analyses were performed in healthy control (HC) normal density neutrophils (NDNs), SLE NDNs and autologous SLE LDGs. The biophysical properties of these neutrophil subsets were analysed by real-time deformability cytometry and lattice light-sheet microscopy. A two-dimensional endothelial flow system and a three-dimensional microfluidic microvasculature mimetic (MMM) were used to decouple the contributions of cell surface mediators and biophysical properties to neutrophil trafficking, respectively. Results: Proteomic and phosphoproteomic differences were detected between HC and SLE neutrophils and between SLE NDNs and LDGs. Increased abundance of type 1 interferon-regulated proteins and differential phosphorylation of proteins associated with cytoskeletal organisation were identified in SLE LDGs relative to SLE NDNs. The cell surface of SLE LDGs was rougher than in SLE and HC NDNs, suggesting membrane perturbances. While SLE LDGs did not display increased binding to endothelial cells in the two-dimensional assay, they were increasingly retained/trapped in the narrow channels of the lung MMM. Conclusions: Modulation of the neutrophil proteome and distinct changes in biophysical properties are observed alongside differences in neutrophil trafficking. SLE LDGs may be increasingly retained in microvasculature networks, which has important pathogenic implications in the context of lupus organ damage and small vessel vasculopathy
LOX-1: A potential driver of cardiovascular risk in SLE patients.
Traditional cardiovascular disease (CVD) risk factors, such as hypertension, dyslipidemia and diabetes do not explain the increased CVD burden in systemic lupus erythematosus (SLE). The oxidized-LDL receptor, LOX-1, is an inflammation-induced receptor implicated in atherosclerotic plaque formation in acute coronary syndrome, and here we evaluated its role in SLE-associated CVD. SLE patients have increased sLOX-1 levels which were associated with elevated proinflammatory HDL, oxLDL and hsCRP. Interestingly, increased sLOX-1 levels were associated with patients with early disease onset, low disease activity, increased IL-8, and normal complement and hematological measures. LOX-1 was increased on patient-derived monocytes and low-density granulocytes, and activation with oxLDL and immune-complexes increased membrane LOX-1, TACE activity, sLOX-1 release, proinflammatory cytokine production by monocytes, and triggered the formation of neutrophil extracellular traps which can promote vascular injury. In conclusion, perturbations in the lipid content in SLE patients' blood activate LOX-1 and promote inflammatory responses. Increased sLOX-1 levels may be an indicator of high CVD risk, and blockade of LOX-1 may provide a therapeutic opportunity for ameliorating atherosclerosis in SLE patients
Using the circulating proteome to assess type I interferon activity in systemic lupus erythematosus.
Type I interferon (IFN) drives pathology in systemic lupus erythematosus (SLE) and can be tracked via IFN-inducible transcripts in blood. Here, we examined whether measurement of circulating proteins, which enter the bloodstream from inflamed tissues, also offers insight into global IFN activity. Using a novel protocol we generated 1,132 aptamer-based protein measurements from anti-dsDN
Transcriptomic, epigenetic, and functional analyses implicate neutrophil diversity in the pathogenesis of systemic lupus erythematosus
Phase 1 double-blind randomized safety trial of the Janus kinase inhibitor tofacitinib in systemic lupus erythematosus
Increased risk of premature cardiovascular disease in systemic lupus erythematosus (SLE) is not well understood, but in animal models, the Janus kinase inhibitor tofacitinib improves related phenotypes. Here the authors report a Phase 1 double-blind randomized trial that shows tofacitinib is safe and well tolerated in in patients with SLE