Implementation of
point-of-care (POC) pharmacogenetic (PGx) testing with personalized treatment recommendations.
POC
genotyping plus expert evaluation of risk factors for ischemic and bleeding ...events.
167 patients underwent PGx testing, 54 (32.3%) were
loss of function carriers, and POC versus standard PGx analysis results for
and
variants matched in 100%. Antiplatelet therapy was adjusted in 44 patients (26.3%), but always required consideration of patient-specific factors.
POC-PGx is reliable and offers clinically relevant advantages for immediate evidence-based adaptations of antiplatelet therapy, whereas in less acute cases conventional PGx testing can also have advantages. Antiplatelet therapy has become more complex, and implementation of PGx-based personalized antiplatelet therapy requires complementary expert knowledge.
Switzerland was amongst the first countries to offer cell-free fetal DNA (cffDNA) testing covered by the health insurance to pregnant women with a risk ≥ 1:1000 for trisomies at first trimester ...combined screening (FTCS). The aim of this study is to evaluate the implementation of this contingent model in a single tertiary referral centre and its effect on gestational age at diagnosing trisomy 21.
Between July 2015 and December 2020 all singleton pregnancies at 11-14 weeks of gestation without major fetal malformation were included and stratified according to their risk at FTCS. Statistical analysis was performed by GraphPad Version 9.1 for Windows.
4424 pregnancies were included. Of 166 (3.8%) pregnancies with a NT ≥ 3.5 mm and/or a risk ≥ 1:10 at FCTS, 130 (78.3%) opted for direct invasive testing. 803 (18.2%) pregnancies had an intermediate risk, 692 (86.2%) of them opted for cffDNA first. 3455 (78.1%) pregnancies had a risk < 1:1000. 63 fetuses were diagnosed with trisomy 21, 47 (74.6%) directly by invasive procedures after FTCS, 16 (25.4%) by cffDNA first.
Most women choose cffDNA or invasive testing as second tier according to national guidelines. Despite the delay associated with cffDNA testing after FCTS, 75% of all trisomy 21 are still diagnosed in the first trimester with this contingent screening model.
Arrays of nanowires (NWs) are currently being established as vehicles for molecule delivery and electrical- and fluorescence-based platforms in the development of biosensors. It is conceivable that ...NW-based biosensors can be optimized through increased understanding of how the nanotopography influences the interfaced biological material. Using state-of-the-art homogenous NW arrays allow for a systematic investigation of how the broad range of NW densities used by the community influences cells. Here it is demonstrated that indium arsenide NW arrays provide a cell-promoting surface, which affects both cell division and focal adhesion up-regulation. Furthermore, a systematic variation in NW spacing affects both the detailed cell morphology and adhesion properties, where the latter can be predicted based on changes in free-energy states using the proposed theoretical model. As the NW density influences cellular parameters, such as cell size and adhesion tightness, it will be important to take NW density into consideration in the continued development of NW-based platforms for cellular applications, such as molecule delivery and electrical measurements.
Chemo-mechanotransduction, the way by which mechanical forces are transformed into chemical signals, plays a fundamental role in many biological processes. The first step of mechanotransduction often ...relies on exposure, under stretching, of cryptic sites buried in adhesion proteins. Likewise, here we report the first example of synthetic surfaces allowing for specific and fully reversible adhesion of proteins or cells promoted by mechanical action. Silicone sheets are first plasma treated and then functionalized by grafting sequentially under stretching poly(ethylene glycol) (PEG) chains and biotin or arginine-glycine-aspartic acid (RGD) peptides. At unstretched position, these ligands are not accessible for their receptors. Under a mechanical deformation, the surface becomes specifically interactive to streptavidin, biotin antibodies, or adherent for cells, the interactions both for proteins and cells being fully reversible by stretching/unstretching, revealing a reversible exposure process of the ligands. By varying the degree of stretching, the amount of interacting proteins can be varied continuously.
Cell deformation occurs in many critical biological processes, including cell extravasation during immune response and cancer metastasis. These cells deform the nucleus, their largest and stiffest ...organelle, while passing through narrow constrictions in vivo and the underlying mechanisms still remain elusive. It is unclear which biochemical actors are responsible and whether the nucleus is pushed or pulled (or both) during deformation. Herein we use an easily-tunable poly-L-lactic acid micropillar topography, mimicking in vivo constrictions to determine the mechanisms responsible for nucleus deformation. Using biochemical tools, we determine that actomyosin contractility, vimentin and nucleo-cytoskeletal connections play essential roles in nuclear deformation, but not A-type lamins. We chemically tune the adhesiveness of the micropillars to show that pulling forces are predominantly responsible for the deformation of the nucleus. We confirm these results using an in silico cell model and propose a comprehensive mechanism for cellular and nuclear deformation during confinement. These results indicate that microstructured biomaterials are extremely versatile tools to understand how forces are exerted in biological systems and can be useful to dissect and mimic complex in vivo behaviour.
Abstract We have recently demonstrated strong nuclear deformation of SaOs-2 osteosarcoma cells on poly- l -lactic acid (PLLA) micropillar substrates. In the present study, we first demonstrated that ...chemical and mechanical properties of the micropillar substrates have no dominant effect on deformation. However, SaOs-2 nucleus deformation could be strongly modulated by varying the pillar size and spacing, highlighting the importance of geometric constraints for shaping the nucleus. Furthermore, comparing the capacity for nuclear deformation in three different osteosarcoma cell lines (SaOs-2, MG-63 and OHS-4) revealed strong cell-type specific differences. Surprisingly, the highly-deformable SaOs-2 cell line displayed the highest cell stiffness as assessed by AFM-based colloidal force spectroscopy and featured a more prominent array of actin fibres above the nucleus, suggesting a link between actin-mediated cell stiffness and cell nucleus deformation. In contrast, in MG-63 and OHS-4 cells dense microtubule and vimentin networks seem to facilitate some nuclear deformation even in the absence of a prominent actin cytoskeleton. Together these results suggest that an interaction of all three cytoskeletal elements is needed for efficient nuclear deformation. In conclusion, the dominant parameters influencing nuclear deformation on micropillar substrates are not their material properties but the substrate geometry together with cell phenotype and cytoskeleton organization.
Mechanical stimuli and geometrical constraints transmitted across the cytoskeleton to the nucleus affect the nuclear morphology and cell function. Human pluripotent stem cells (hPSCs) represent an ...effective tool for evaluating transitions in nuclear deformability from the pluripotent to differentiated stage, and for deciphering the underlying mechanisms. We report the first study that investigates the nuclear deformability induced by geometrical constraints of hPSCs both in the pluripotent stage and during early germ layer specification. We specifically developed micro-structured surfaces coupled with high-content imaging analysis algorithms to quantitatively characterize nuclear deformability. Our results show that hPSCs possess high nuclear deformability, which does not alter pluripotency. We observed nuclear deformability transition along early germ layer specification: during early ectoderm differentiation nuclear deformability is strongly reduced, during early endoderm differentiation nuclei keep a deformed shape and during early mesoderm specification they show an intermediate behaviour. Different mRNA expressions between hPSCs differentiated on flat and micro-structured surfaces have been observed along early mesoderm and early endoderm specification. In order to better understand the mechanisms of the nuclear deformability transition observed during early ectoderm differentiation, we also employed cytoskeletal and nuclear protein inhibitors to evaluate their role in determining the nuclear shape. Actin and nesprin are essential for maintaining deformed nuclei, while lamin A/C and intermediate filaments confer rigidity to the nucleus. This study suggests that nuclear deformability is highly regulated during differentiation.
Le travail présenté dans cette thèse est le résultat d'une collaboration fructueuse entre la chimie, la physique et la biologie. En effet, des matériaux avec des propriétés physico-chimiques très ...contrôlées ont été mis à profit dans le but de caractériser des fonctions cellulaires complexes. Nous présentons tout d'abord la création d'un outil permettant l'étude de la mécanotransduction cellulaire. L'originalité de cet outil est basé sur son activation par étirement permettant de lier réversiblement les cellules à la surface. Nous avons ensuite étudié des comportements de cellules souches et cancéreuses en réponse à des microtopographies sous forme de piliers. Cette approche a permis de définir un comportement cancéreux caractérisé par une déformation prononcée des corps et noyaux cellulaires. Nous montrons aussi que l'utilisation de cette surface couverte de micro-piliers permet de décrire la mécano-biologie de cellules cancéreuses. En effet, ce substrat à topographie contrôlée a permis de montrer que la chimie et la rigidité du substrat n'ont que peu d'incidence sur la déformation des cellules cancéreuses, alors que les éléments du cytosquelette sont primordiaux et que sans eux, la déformation n'est pas possible. Nous avons ensuite inhibé une à une des protéines de l'enveloppe et de la lamina nucléaire afin d'évaluer leur implication dans ces mécanismes de déformation. En parallèle, un séquençage total des ARN (Acides RiboNucléiques) de cellules déformées et non déformées a été réalisé dans le but de visualiser d'éventuelles modifications dans l'expression génique. Ces déformations des cellules cancéreuses entre les micro-piliers ont été comparées à celles que subissent les cellules lors de la traversée de membranes poreuses (Chambres de Boyden). Ces comparaisons nous ont permis d'identifier que plusieurs mécanismes peuvent aboutir à la déformation de cellules cancéreuses et en particulier de leurs noyaux. Nous montrons dans une dernière partie que la mitose cellulaire s'effectue sur les surfaces microstructurées. Nous décrivons une ségrégation des chromosomes qui semble être non parallèle. Toutefois, ces divisions atypiques ne causent pas davantage d'accidents mitotiques.
The work shown in this thesis is the outcome of a successful collaboration between chemistry, physics and biology. Indeed, materials with well controlled parameters have been used in order to characterize complex cellular functions. We first introduce the creation of one tool which allow the study of cells mechanotransduction. The originality of this tool is based on its activation by stretching which allow a reversible adhesion of cells to the surface.Then, we studied the behavior of stem cells and cancerous cells on micropillared surfaces. This approach allowed us to describe a cancerous behavior of cells characterized by strong deformations of cells bodies and nuclei. We also showed that the use of such micropillared surfaces allowed us to describe cancerous cells mecanobiology. Indeed, this substrate with a well controlled topography allowed us to show that substrates chemistry and stiffness have only little effects on cancerous cells deformation while cytoskeleton components are necessary. More specifically, the deformation is impossible without the cytoskeleton. We also inhibited the nuclear envelope proteins and nuclear lamina proteins in order to evaluate their involvement in cells deformation mechanism. In the same time, a total RNA (RiboNucleic Acids) sequencing of deformed and non deformed cells have been done in order to identify an eventual modification in gene expression.These deformations of cancerous cells between micropillars have been compared to the deformation of cells during the transmigration through porous membranes (Boyden chambers). These comparisons allowed us to identify several mechanisms which lead to cells deformation and more specifically to nuclei deformation.We showed in a last part that cells can divide on micropillared surfaces. We described a non parallel like segregation of chromosomes. However, these unusual mitosis didn't lead to supernumerary troubles in cell division.
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