Mixing tests are a relatively simple procedure used in the hemostasis laboratory as a first-line investigation into the cause of an abnormal screening test, typically a prolonged activated partial ...thromboplastin time and/or a prolonged prothrombin time. The mixing test involves combining the test plasma with normal plasma, then repeating the screening test on the mixture to assess whether the clotting time becomes normal or remains prolonged. The primary purpose of a mixing test is to guide further investigations. When mixing test results "normalize," this suggests the test plasma is deficient in clotting factor(s) and thus specific factor assays can be performed to determine which are reduced. When the mixing test result does not "normalize," this suggests the presence of an inhibitor or other type of interference (e.g., the presence of an anticoagulant such as high-dose heparinoids), and so the laboratory needs to determine if this is a lupus anticoagulant or a specific coagulation factor inhibitor, or another type of inhibitor. Because these follow-up investigations are more costly and time-consuming than the basic screening tests, the appropriate performance and interpretation of mixing tests is advantageous for the laboratory. Moreover, the correct laboratory approach is also clinically relevant, as patient management is ultimately affected, and an incorrect interpretation may lead to inappropriate therapies being established. Components of a mixing test that can influence result interpretation include the sensitivity of the used screening reagents to various factor deficiencies and inhibitors, the source or composition of the normal plasma, and the setting of cutoffs for the formula used in expressing mixing test results. Numerous and differing criteria for mixing test interpretation have been suggested historically, which can lead to confusion as to which approach is the most appropriate. The use of differing criteria will also lead to differing interpretations regarding "normalization." For this pivotal reason, standardized mixing test procedures and a consistent set of validated interpretive criteria represent the most favorable approach to maximizing the utility of a mixing test, and ensure the most accurate diagnosis for investigated patients.
GPS technology is widely used to produce detailed data on the movement of people. Analysing massive amounts of GPS data, however, can be cumbersome. We present a novel approach to processing such ...data to aid interpretation and understanding of the aggregated movement of visitors in natural recreational areas. It involves the combined analysis of two kinds of movement patterns: ‘Movement Suspension Patterns’ (MSPs) and ‘Generalized Sequential Patterns’ (GSPs). MSPs denote the suspension of movement when walkers stop at a place, and are used to discover places of interest to visitors. GSPs represent the generalized sequence in which the places are visited, regardless of the trajectory followed, and are used to uncover commonalities in the way that people visit the area. Both patterns were analysed in a geographical context to characterise the aggregated flow of people and provide insights into visitors’ preferences and their interactions with the environment. We demonstrate the application of the approach in the Dwingelderveld National Park (The Netherlands).
Display omitted
► Movement patterns help to understand spatial behaviour of visitors in natural areas. ► Spatial statistics and data mining are combined to extract these movement patterns. ► Movement Suspension Patterns are used to uncover the main places of interest for the visitors. ► Generalized Sequential Patterns are used to analyse the visitor flows among places.
Neuroferritinopathy (NF) is a movement disorder caused by alterations in the L-ferritin gene that generate cytosolic free iron. NF is a unique pathophysiological model for determining the direct ...consequences of cell iron dysregulation. We established lines of induced pluripotent stem cells from fibroblasts from two NF patients and one isogenic control obtained by CRISPR/Cas9 technology. NF fibroblasts, neural progenitors, and neurons exhibited the presence of increased cytosolic iron, which was also detectable as: ferritin aggregates, alterations in the iron parameters, oxidative damage, and the onset of a senescence phenotype, particularly severe in the neurons. In this spontaneous senescence model, NF cells had impaired survival and died by ferroptosis. Thus, non-ferritin-bound iron is sufficient per se to cause both cell senescence and ferroptotic cell death in human fibroblasts and neurons. These results provide strong evidence supporting the primary role of iron in neuronal aging and degeneration.
Display omitted
•NF is a unique pathophysiological model for analyzing cellular iron dysregulation•NF fibroblast/iPSC-derived NPCs and neurons show a phenotype of iron mobilization•Free iron is sufficient per se to cause both cell senescence and ferroptosis•Iron has a primary role in neuronal aging and degeneration
In this article Sonia Levi and colleagues show that non-ferritin-bound iron is able to cause cell senescence and ferroptotic cell death in human fibroblasts and neurons, underlining the primary role of iron in accelerating the processes of aging and neurodegeneration. These findings provide implications for studies investigating the role of iron in a more general context of neurodegenerative diseases.
This study explores the potential influence of the urban built environment on pedestrian flow in an intermediate Latin American city, Cuenca-Ecuador. Data from samples of 48 street segments were ...analyzed to explore how physical and spatial features of streets and sidewalks, as well as land use and occupation conditions influence the number of pedestrians. A quantitative approach was used to model the individual and combined influences of several variables on pedestrian counts using multiple regression models. Results from statistical modeling indicate that variables related to the physical features of the streets, such as sidewalk width, are positively correlated to pedestrian counts, whereas parking space and front setback are negatively correlated. We conclude that streets in our study area are largely inadequate for pedestrians due to their poor design, scarce walking infrastructure, and the prevalence of all sorts of obstacles on the sidewalks. Pedestrians, however, seem to cope with this adverse environment by adopting different strategies. We expect that this study will help city planners design better environments for non-motorized travel in intermediate cities.
The aim of this work was to investigate the effect that adding charcoal to a coking coal has upon the CO2 reactivity and structure of cokes produced at a laboratory scale. Charcoal was added to a ...vitrinite-rich medium volatile coking coal in three amounts (3, 5 and 8wt%) and in two different particle size ranges (below 1mm and between 3 and 4mm) and carbonization was conducted in a laboratorial scale coke oven. Thermogravimetric analyses were used to assess coke reactivity towards CO2 under isothermal and nonisothermal conditions. Morphological analyses via optical and scanning electron microscopies using samples from before and after gasification were also carried out. It was found that controlling the amount and the particle size of charcoal added, coke reactivity did not differ considerably from the reference coke, although the TGA indicated that the addition of charcoal has the tendency to increase coke reactivity. The main structural changes due charcoal addition were the increase of coke surface area and the decrease of its structural order, justifying the noticed increase of coke reactivity.
•CO2-reactivity and structure of cokes from coal/charcoal blends were assessed.•Cokes were more reactive and gasification started at a lower temperature.•Charcoal addition increased coke surface area and reduced coke cohesion.•Smaller sized charcoal caused the greatest impact on coke reactivity and structure.
Pantothenate kinase‐associated neurodegeneration (PKAN) is an early onset and severely disabling neurodegenerative disease for which no therapy is available. PKAN is caused by mutations in PANK2, ...which encodes for the mitochondrial enzyme pantothenate kinase 2. Its function is to catalyze the first limiting step of Coenzyme A (CoA) biosynthesis. We generated induced pluripotent stem cells from PKAN patients and showed that their derived neurons exhibited premature death, increased ROS production, mitochondrial dysfunctions—including impairment of mitochondrial iron‐dependent biosynthesis—and major membrane excitability defects. CoA supplementation prevented neuronal death and ROS formation by restoring mitochondrial and neuronal functionality. Our findings provide direct evidence that PANK2 malfunctioning is responsible for abnormal phenotypes in human neuronal cells and indicate CoA treatment as a possible therapeutic intervention.
Synopsis
Mutations in PANK2 cause PKAN disease. This belongs to a group of disorders characterized by progressive neurodegeneration and excessive iron deposition in the brain. PANK2 enzyme catalyzes the first step in CoA synthesis. iPSC‐derived neurons from PKAN patients display abnormal phenotypes.
PKAN neurons show excitability defects and neuronal death.
PKAN neurons present increased ROS levels and abnormal mitochondrial morphology and functions.
PKAN neurons present cellular iron deficiency.
PANK2 expression in patients' neurons reverts most of the abnormal phenotypes.
CoA treatment restores the abnormal PKAN neuronal functions.
Mutations in PANK2 cause PKAN disease. This belongs to a group of disorders characterized by progressive neurodegeneration and excessive iron deposition in the brain. PANK2 enzyme catalyzes the first step in CoA synthesis. iPSC‐derived neurons from PKAN patients display abnormal phenotypes.
Inflammation is a process that has been actively related with the onset of several neurodegenerative disorders including Alzheimer disease (AD). However, the precise implications of inflammatory ...response for neurodegeneration have not been elucidated. A current hypothesis considers that extracellular insults to neurons could trigger the production of inflammatory cytokines by astrocytes and microglia. These cytokines, namely, interleukin (IL)-1β, TNFα, and IL-6, could affect the normal behavior of neuronal cells. In the present study, we describe the effect of the administration at physiologic doses of one of these cytokines, IL-6, to hippocampal neurons, on the protein kinase pathways as well as on the tau phosphorylation patterns. IL-6-treated neurons exhibited an increase in the amount of anomalously hyperphosphorylated tau protein in epitopes dependent on proline-directed protein kinases (PDPKs). On the basis of our data, the observed increase of tau epitopes of Alzheimer type is explained by an increase of intraneuronal levels of p35 activator and in the activity of the protein kinase cdk5 in response to this cytokine. Further confirmation of cdk5 involvement in this process was based on the findings that inhibition of the kinase activity with butyrolactone-I prevents the appearance of tau of Alzheimer type in IL-6-treated neurons. Additional studies suggest that an increase of cdk5 activity could be mediated by a known signaling cascade described for IL-6 function, namely, the MAPK–p38 signaling pathway. Stimulation of the IL-6 pathway appears to increase the tau epitopes of Alzheimer type, as demonstrated in studies with specific inhibitors. These results support the findings of a pathologic role for IL-6 in the neuroinflammatory response as related with the pathogenesis of neuronal degeneration.
Cell signaling is central to neuronal activity and its dysregulation may lead to neurodegeneration and cognitive decline. Here, we show that selective genetic potentiation of neuronal ERK signaling ...prevents cell death in vitro and in vivo in the mouse brain, while attenuation of ERK signaling does the opposite. This neuroprotective effect mediated by an enhanced nuclear ERK activity can also be induced by the novel cell penetrating peptide RB5. In vitro administration of RB5 disrupts the preferential interaction of ERK1 MAP kinase with importinα1/KPNA2 over ERK2, facilitates ERK1/2 nuclear translocation, and enhances global ERK activity. Importantly, RB5 treatment in vivo promotes neuroprotection in mouse models of Huntington's (HD), Alzheimer's (AD), and Parkinson's (PD) disease, and enhances ERK signaling in a human cellular model of HD. Additionally, RB5-mediated potentiation of ERK nuclear signaling facilitates synaptic plasticity, enhances cognition in healthy rodents, and rescues cognitive impairments in AD and HD models. The reported molecular mechanism shared across multiple neurodegenerative disorders reveals a potential new therapeutic target approach based on the modulation of KPNA2-ERK1/2 interactions.
The main laboratory characteristic of lupus anticoagulants (LA) is their ability to prolong phospholipid-dependent clotting time in vitro. The laboratory demonstration of LA requires a systematic ...approach combined with an awareness of the many variables that can affect test results. The ideal testing procedures are those sensitive enough to detect weak LA and specific enough so as not to produce incorrect conclusions. International guidelines have been published to assist laboratories in applying correct testing processes. The most recently published guidelines from the International Society on Thrombosis and Haemostasis update the criteria for detecting the presence of LA that were presented in the 1995 guidelines. Some of the specific recommendations relate to the key areas of setting cut-off levels for screening, mixing, and confirmatory procedures. The more challenging aspects of testing for LA include maintaining sensitivity and specificity of the assays, especially in the presence of anticoagulant therapy.
Acute myeloid leukemia (AML) is the most common form of adult acute leukemia with ~20,000 new cases yearly. The disease develops in people of all ages, but is more prominent in the elderly, who due ...to limited treatment options, have poor overall survival rates. Monoclonal antibodies (mAb) targeting specific cell surface molecules have proven to be safe and effective in different haematological malignancies. However, AML target molecules are currently limited so discovery of new targets would be highly beneficial to patients. We examined the C-type lectin receptor CD302 as a potential therapeutic target for AML due to its selective expression in myeloid immune populations. In a cohort of 33 AML patients with varied morphological and karyotypic classifications, 88% were found to express CD302 on the surface of blasts and 80% on the surface of CD34+ CD38- population enriched with leukemic stem cells. A mAb targeting human CD302 was effective in mediating antibody dependent cell cytotoxicity and was internalised, making it amenable to toxin conjugation. Targeting CD302 with antibody limited in vivo engraftment of the leukemic cell line HL-60 in NOD/SCID mice. While CD302 was expressed in a hepatic cell line, HepG2, this molecule was not detected on the surface of HepG2, nor could HepG2 be killed using a CD302 antibody-drug conjugate. Expression was however found on the surface of haematopoietic stem cells suggesting that targeting CD302 would be most effective prior to haematopoietic transplantation. These studies provide the foundation for examining CD302 as a potential therapeutic target for AML.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
