37 research outputs found
Global lung function initiative 2012 reference values for spirometry in Asian Americans
Background
Spirometry reference values specifically designed for Asian Americans are currently unavailable. The performance of Global Lung Function Initiative 2012 (GLI-2012) equations on assessing spirometry in Asian Americans has not been evaluated. This study aimed to assess the fitness of relevant GLI-2012 equations for spirometry in Asian Americans.
Methods
Asian subjects who never smoked and had qualified spirometry data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2011–2012. Z-scores of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC were separately constructed with GLI-2012 equations for North East (NE) Asians, South East (SE) Asians, and individuals of mixed ethnic origin (Mixed). In addition, Proportions of subjects with observed spirometry data below the lower limit of normal (LLN) were also evaluated on each GLI-2012 equation of interest.
Results
This study included 567 subjects (250 men and 317 women) aged 6–79 years. Spirometry z-scores (z-FEV1, z-FVC, and z-FEV1/FVC) based on GLI-2012 Mixed equations had mean values close to zero (− 0.278 to − 0.057) and standard deviations close to one (1.001 to 1.128); additionally, 6.0% (95% confidence interval (CI) 3.1–8.9%) and 6.4% (95% CI 3.7–9.1%) of subjects were with observed data below LLN for FEV1/FVC in men and women, respectively. In contrast, for NE Asian equations, all mean values of z-FEV1 and z-FVC were smaller than − 0.5; for SE Asian equations, mean values of z-FEV1/FVC were significantly smaller than zero in men (− 0.333) and women (− 0.440).
Conclusions
GLI-2012 equations for individuals of mixed ethnic origin adequately fitted spirometry data in this sample of Asian Americans. Future studies with larger sample sizes are needed to confirm these findings
Aβ Mediated Diminution of MTT Reduction—An Artefact of Single Cell Culture?
The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) reduction assay is a frequently used and easily reproducible method to measure beta-amyloid (Aβ) toxicity in different types of single cell culture. To our knowledge, the influence of Aβ on MTT reduction has never been tested in more complex tissue. Initially, we reproduced the disturbed MTT reduction in neuron and astroglia primary cell cultures from rats as well as in the BV2 microglia cell line, utilizing four different Aβ species, namely freshly dissolved Aβ (25-35), fibrillar Aβ (1-40), oligomeric Aβ (1-42) and oligomeric Aβ (1-40). In contrast to the findings in single cell cultures, none of these Aβ species altered MTT reduction in rat organotypic hippocampal slice cultures (OHC). Moreover, application of Aβ to acutely isolated hippocampal slices from adult rats and in vivo intracerebroventricular injection of Aβ also did not influence the MTT reduction in the respective tissue. Failure of Aβ penetration into the tissue cannot explain the differences between single cells and the more complex brain tissue. Thus electrophysiological investigations disclosed an impairment of long-term potentiation (LTP) in the CA1 region of hippocampal slices from rat by application of oligomeric Aβ (1-40), but not by freshly dissolved Aβ (25-35) or fibrillar Aβ (1-40). In conclusion, the experiments revealed a glaring discrepancy between single cell cultures and complex brain tissue regarding the effect of different Aβ species on MTT reduction. Particularly, the differential effect of oligomeric versus other Aβ forms on LTP was not reflected in the MTT reduction assay. This may indicate that the Aβ oligomer effect on synaptic function reflected by LTP impairment precedes changes in formazane formation rate or that cells embedded in a more natural environment in the tissue are less susceptible to damage by Aβ, raising cautions against the consideration of single cell MTT reduction activity as a reliable assay in Alzheimer's drug discovery studies
Conjunctivitis in dupilumab clinical trials
Background Dupilumab blocks the shared receptor component for interleukin (IL)-4
and IL-13. It is approved in the U.S.A. for patients aged ≥ 12 years with moderate-tosevere atopic dermatitis (AD) uncontrolled by topical prescription medicines or who
cannot use topical medicines, for patients in Japan whose AD is uncontrolled with
existing therapies, for patients with moderate-to-severe AD in Europe who are candidates for systemic therapy and for patients aged ≥ 12 years for maintenance treatment
of moderate-to-severe asthma uncontrolled with their current medicines. AD trials
have reported increased incidence of conjunctivitis for dupilumab vs. placebo.
Objectives To characterize further the occurrence and risk factors of conjunctivitis
in dupilumab clinical trials.
Methods We evaluated randomized placebo-controlled trials of dupilumab in AD
(n = 2629), asthma (n = 2876), chronic rhinosinusitis with nasal polyps
(CRSwNP) (n = 60) and eosinophilic oesophagitis (EoE) (n = 47).
Results In most AD trials, dupilumab-treated patients had higher conjunctivitis incidence than placebo controls. Higher baseline AD severity and previous history of conjunctivitis were associated with increased conjunctivitis incidence. Conjunctivitis was
mostly mild to moderate. Most cases recovered or resolved during the treatment period; two patients permanently discontinued dupilumab due to conjunctivitis or keratitis. Common treatments included ophthalmic corticosteroids, antibiotics, and
antihistamines or mast cell stabilizers. Most cases were diagnosed by the investigators.
In asthma and CRSwNP trials, the incidence of conjunctivitis was lower for both
dupilumab and placebo than in AD trials; dupilumab did not increase the incidence
compared with placebo. In the EoE trial, no patients had conjunctivitis.
Conclusions Conjunctivitis was more frequent with dupilumab treatment in most
AD trials. In dupilumab trials in other type 2 diseases, incidence of conjunctivitis was overall very low, and was similar for dupilumab and placebo. In AD, the
incidence of conjunctivitis was associated with AD severity and prior history of
conjunctivitis. The aetiology and treatment of conjunctivitis in dupilumab-treated
patients require further study
Localization Subsystem Simulation for Mobile Robot
Tato práce řeší implementaci lokalizačního algoritmu pro lokalizační subsystém mobilního robotu. Výstupem práce je simulační program v jazyce C\#, který simuluje chování senzorů, pohyb a lokalizační algoritmus založený na pravděpodobnosti. Konkrétně se jedná o algoritmus Monte Carlo. Simulační software obsahuje možnost výběru mapy, grafické zobrazení průběhu simulace, krokování lokalizačního algoritmu Monte Carlo, LiDAR pro měření vzdálenosti, nastavení šumu a nastavení hustoty částic pro MCL.The thesis deals with an implementation of a localization algorithm for a localization subsystem of a mobile robot. The outcome is a simulation program in C\# language which simulates sensor behaviour, motion and localization algorithm based on probability. Specifically, it is Monte Carlo algorithm. The simulation software contains a possibility to choose a map, graphic projection of a simulation development, debuging of the Monte Carlo localization algorithm, LiDAR for distance measuring, noise level setting and density of particles for MCL setting.450 - Katedra kybernetiky a biomedicínského inženýrstvívýborn
Macrophage signaling in HIV-1 infection
The human immunodeficiency virus-1 (HIV-1) is a member of the lentivirus genus. The virus does not rely exclusively on the host cell machinery, but also on viral proteins that act as molecular switches during the viral life cycle which play significant functions in viral pathogenesis, notably by modulating cell signaling. The role of HIV-1 proteins (Nef, Tat, Vpr, and gp120) in modulating macrophage signaling has been recently unveiled. Accessory, regulatory, and structural HIV-1 proteins interact with signaling pathways in infected macrophages. In addition, exogenous Nef, Tat, Vpr, and gp120 proteins have been detected in the serum of HIV-1 infected patients. Possibly, these proteins are released by infected/apoptotic cells. Exogenous accessory regulatory HIV-1 proteins are able to enter macrophages and modulate cellular machineries including those that affect viral transcription. Furthermore HIV-1 proteins, e.g., gp120, may exert their effects by interacting with cell surface membrane receptors, especially chemokine co-receptors. By activating the signaling pathways such as NF-kappaB, MAP kinase (MAPK) and JAK/STAT, HIV-1 proteins promote viral replication by stimulating transcription from the long terminal repeat (LTR) in infected macrophages; they are also involved in macrophage-mediated bystander T cell apoptosis. The role of HIV-1 proteins in the modulation of macrophage signaling will be discussed in regard to the formation of viral reservoirs and macrophage-mediated T cell apoptosis during HIV-1 infection
Effects of Prostratin on T-Cell Activation and Human Immunodeficiency Virus Latency
Human immunodeficiency virus (HIV) replication is linked to cellular gene transcription and requires target cell activation. The latent reservoir of HIV-1 in quiescent T cells is thought to be a major obstacle to clearance of infection by highly active antiretroviral therapy (HAART). Thus, identification of agents that can induce expression of latent virus may, in the presence of HAART, allow elimination of the infected cells by the immune response. We previously used the SCID-hu (Thy/Liv) mouse model to establish that activation-inducible HIV can be generated at high frequency during thymopoiesis. Latently infected mature thymocytes can be exported into the periphery, providing an efficient primary cell model to determine cellular activation signals that induce renewed expression of latent virus. Here we characterized the effects of prostratin, a non-tumor-promoting phorbol ester, on primary human peripheral blood lymphocytes (PBLs) and assessed its ability to reactivate latent HIV infection from thymocytes and PBLs in the SCID-hu (Thy/Liv) model. Prostratin stimulation alone did not induce proliferation of quiescent PBLs; however, it could provide a secondary signal in the context of T-cell receptor stimulation or a primary activation signal in the presence of CD28 stimulation to induce T-cell proliferation. While prostratin alone was not sufficient to allow de novo HIV infection, it efficiently reactivated HIV expression from latently infected cells generated in the SCID-hu mouse. Our data indicate that prostratin alone is able to specifically reactivate latent virus in the absence of cellular proliferation, making it an attractive candidate for further study as an adjunctive therapy for the elimination of the latent HIV reservoir