28 research outputs found
Do We Have a Proper Model?
It has been reported recently that the cystic fibrosis transmembrane
conductance regulator (CFTR) besides transcellular chloride transport, also
controls the paracellular permeability of bronchial epithelium. The aim of
this study was to test whether overexpressing wtCFTR solely regulates
paracellular permeability of cell monolayers. To answer this question we used
a CFBE41o– cell line transfected with wtCFTR or mutant F508del-CFTR and
compered them with parental line and healthy 16HBE14o– cells. Transepithelial
electrical resistance (TER) and paracellular fluorescein flux were measured
under control and CFTR-stimulating conditions. CFTR stimulation significant
decreased TER in 16HBE14o– and also in CFBE41o– cells transfected with wtCFTR.
In contrast, TER increased upon stimulation in CFBE41o– cells and CFBE41o–
cells transfected with F508del-CFTR. Under non-stimulated conditions, all four
cell lines had similar paracellular fluorescein flux. Stimulation increased
only the paracellular permeability of the 16HBE14o– cell monolayers. We
observed that 16HBE14o– cells were significantly smaller and showed a
different structure of cell-cell contacts than CFBE41o– and its overexpressing
clones. Consequently, 16HBE14o– cells have about 80% more cell-cell contacts
through which electrical current and solutes can leak. Also tight junction
protein composition is different in ‘healthy’ 16HBE14o– cells compared to
‘cystic fibrosis’ CFBE41o– cells. We found that claudin-3 expression was
considerably stronger in 16HBE14o– cells than in the three CFBE41o– cell
clones and thus independent of the presence of functional CFTR. Together,
CFBE41o– cell line transfection with wtCFTR modifies transcellular
conductance, but not the paracellular permeability. We conclude that CFTR
overexpression is not sufficient to fully reconstitute transport in CF
bronchial epithelium. Hence, it is not recommended to use those cell lines to
study CFTR-dependent epithelial transport
3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm
Positron emission tomographs (PET) do not measure an image directly. Instead,
they measure at the boundary of the field-of-view (FOV) of PET tomograph a
sinogram that consists of measurements of the sums of all the counts along the
lines connecting two detectors. As there is a multitude of detectors build-in
typical PET tomograph structure, there are many possible detector pairs that
pertain to the measurement. The problem is how to turn this measurement into an
image (this is called imaging). Decisive improvement in PET image quality was
reached with the introduction of iterative reconstruction techniques. This
stage was reached already twenty years ago (with the advent of new powerful
computing processors). However, three dimensional (3D) imaging remains still a
challenge. The purpose of the image reconstruction algorithm is to process this
imperfect count data for a large number (many millions) of lines-of-responce
(LOR) and millions of detected photons to produce an image showing the
distribution of the labeled molecules in space.Comment: 10 pages, 7 figure
Towards Becoming an Ecology of Care
Thinking about care in the organization of an ecology is central to the interdisciplinary research group Care Ecologies; found during a lockdown in the spring of 2021 and hosted by ARIAS Platform for Research Through the Arts and Sciences in Amsterdam. In Towards Becoming an Ecology of Care group members Valentina Curandi, Inte Gloerich, Ania Molenda, Maaike Muntinga, Natalia Sanchez Querubin, Nienke Scholts and Marloeke van der Vlugt, offer an initial articulation on their approaches and principles – performative practices, reflection, speculations - of what an ecology of care could be. While each bringing in different understandings of care, staying with those differences shaped the ways in which the agenda of the research group has been (un)settled. To exchange knowledge and experiences, the group uses various on- and off-line frameworks, like presentations and practice sessions. Exploring how activities that sustain a research group – coordinating, meeting, writing and documenting – may be done with care, this paper attempts to present a speculative proposition for functioning as a research ecology on and around care. Bringing into focus what care can do, while being attentive to what is neglected. This is not only done in writing but also becomes visible in the accompanying images compiled of material and immaterial memories. It is an ongoing process, for which the writing of this paper became a catalyst for reflection. While not aiming for clear answers the authors invite themselves and others to become more aware, devising and testing work strategies for care-based practices
SEMG frequency of the erector spinae in children with lesions scoliotic
The aim of the study was to analyze the frequency of SEMG rectifier spine in children with scoliosis. Analysis electromyographic rectifier spine was performed using a 12-channel camera Noraxon TeleMyo DTS. The shape of the spine was assessed using optoelectronic Diers formetric III 4D. The research was Carried out in the Posturology Laboratory at the Faculty of Medicine and Health Sciences, UJK in Kielce (Poland). In the group of children with scoliosis curvature of the most frequently occurred on the location of the rib. In girls, it represented (62%) in boys (56%). In boys, thoracic scoliosis twoarched right-handed and left-sided lumbar were 19 (30%). The largest absolute differences in the frequency of EMG rectifier spine in girls with scoliosis group occurred lying ahead for the variable lumbar left (S = 36, 99). In turn, the value of the variable lower limbs up the right side of the lumbar was absolutely the most diverse among boys in the group of scoliosis (S = 40.54). Univariate analysis of variance indicated that there are significant differences in the measurements of intra-frequency variable SMEG rectifier spine torso upright thoracic among boys (p = 0.04). This means that the values of the variables were significantly different between groups attitudes scoliotic, scoliosis and normal boys, and the value of the significance level was less than 0.5 (
Plastic scintillators for positron emission tomography obtained by the bulk polymerization method
This paper describes three methods regarding the production of plastic
scintillators. One method appears to be suitable for the manufacturing of
plastic scintillator, revealing properties which fulfill the requirements of
novel positron emission tomography scanners based on plastic scintillators. The
key parameters of the manufacturing process are determined and discussed.Comment: 7 pages, 4 figure
A novel method based solely on field programmable gate array (FPGA) units enabling measurement of time and charge of analog signals in positron emission tomography (PET)
Abstract: This article presents an application of a novel technique for precise measurements of time and charge based solely on a field programmable gate array (FPGA) device for positron emission tomography (PET). The described approach simplifies electronic circuits, reduces the power consumption, lowers costs, merges front-end electronics with digital electronics, and also makes more compact final design. Furthermore, it allows to measure time when analog signals cross a reference voltage at different threshold levels with a very high precision of ~15 ps (rms) and thus enables sampling of signals in a voltage domain
Alternative splicing of calcium channel CaV1.1
Alternative splicing is likely to be the primary source of human proteomic diversity. Our aim was to investigate the splice variants of the human CACNA1S gene. The encoded voltage-gated calcium channel CaV1.1 is mostly expressed in skeletal muscle cell, where it controls the activity of intracellular calcium realize channel RyR1, during excitation-contraction coupling. We extracted RNA from human muscle and human myotubes cell culture, performed reverse-transcriptase PCR and direct sequencing of all variants found. We identified 13 different splice variants: 9 generating premature truncations and 4 generating putatively functional channels. Premature truncation could have three different consequences for CaV1.1 channel: nonsense-mediated decay (NMD), leaky ribosomal scanning, or dominant-negative calcium channel suppression.
We focussed on splice variant excluding exon 29 (DELTA-29). This region codes most of IVS3-S4 loop. The IVS3-S4 region is subjected to extensive splicing in multiple calcium channels genes and different species from Drosophila to human. Variant without exon 29 is highly expressed in human and mouse myotubes (~ 70 % of transcripts), but relatively rare in adult muscle (~ 10 % of transcripts). For this reason, we undertook functional studies of this variant. Combined whole cell patch clamp and intracellular fluorescence Ca2+ measurements were performed in transfected GLT myotubes loaded with the fluorescent Ca2+ indicator Fluo-4. Current kinetics of wild type and DELTA-29 were clearly different, the I-V curve of the variant was - 32 mV shifted. Our results are nicely consistent with findings in other homologous calcium channels: There appears to be a correlation between the IVS3-S4 linker length of and the amount of hyperpolarizing shift in the voltage dependence of activation when compared with the WT. Alternative splicing of exon 29 appears to underlie the key shift in voltage parameters. Our research provided valuable evidence on the dominant expression of DELTA-29 channels in neonates and regenerative muscles. It also provided further evidence for phenotypic variation generated by alternative splicing to produce proteomic diversity
Deficits of Sensory Integration and Balance as Well as Scoliotic Changes in Young Schoolgirls
The aim of this study was to assess the relationship between sensory integration and balance deficits as well as scoliotic changes in young schoolgirls. The study comprised 54 girls aged 11 years with scoliotic changes. The Clinical Test of Sensory Integration and Balance of the Biodex Balance System platform were used to analyze the deficits in sensory integration and balance. Scoliotic changes were assessed using the Diers Formetric III 4D optoelectronic method. In the present study, there was a significant relationship between sensory integration and balance deficits as well as spine curvature angle (°) (p = 0.01), vertebral surface rotation (°) (p = 0.03), pelvic tilt (°) (p = 0.02), and lateral deviation (mm) (p = 0.04). The integration of the sensory systems has a positive effect on the structure of the intended and controlled movement as well as body posture and the development of the spine. In the treatment of scoliotic changes, one should also consider exercises that improve sensory integration as well as position and balance reactions
Paracellular transport through healthy and cystic fibrosis bronchial epithelial cell lines--do we have a proper model?
It has been reported recently that the cystic fibrosis transmembrane conductance regulator (CFTR) besides transcellular chloride transport, also controls the paracellular permeability of bronchial epithelium. The aim of this study was to test whether overexpressing wtCFTR solely regulates paracellular permeability of cell monolayers. To answer this question we used a CFBE41o- cell line transfected with wtCFTR or mutant F508del-CFTR and compered them with parental line and healthy 16HBE14o- cells. Transepithelial electrical resistance (TER) and paracellular fluorescein flux were measured under control and CFTR-stimulating conditions. CFTR stimulation significant decreased TER in 16HBE14o- and also in CFBE41o- cells transfected with wtCFTR. In contrast, TER increased upon stimulation in CFBE41o- cells and CFBE41o- cells transfected with F508del-CFTR. Under non-stimulated conditions, all four cell lines had similar paracellular fluorescein flux. Stimulation increased only the paracellular permeability of the 16HBE14o- cell monolayers. We observed that 16HBE14o- cells were significantly smaller and showed a different structure of cell-cell contacts than CFBE41o- and its overexpressing clones. Consequently, 16HBE14o- cells have about 80% more cell-cell contacts through which electrical current and solutes can leak. Also tight junction protein composition is different in 'healthy' 16HBE14o- cells compared to 'cystic fibrosis' CFBE41o- cells. We found that claudin-3 expression was considerably stronger in 16HBE14o- cells than in the three CFBE41o- cell clones and thus independent of the presence of functional CFTR. Together, CFBE41o- cell line transfection with wtCFTR modifies transcellular conductance, but not the paracellular permeability. We conclude that CFTR overexpression is not sufficient to fully reconstitute transport in CF bronchial epithelium. Hence, it is not recommended to use those cell lines to study CFTR-dependent epithelial transport
Scheme of the continuous transepithelial resistance measurement device (cTER).
<p>The ThinCert culture plate contains eight filter inserts with cell monolayers. The upper plate (lid) has six titanium electrodes for each insert, four electrodes to inject the current and two to measures the voltage. Electrodes are arranged in a way that resulted in a fairly homogenous electrical field.</p