Diagnostics (Basel)
February 2023
Developers and users of artificial-intelligence-based tools for automatic contouring and treatment planning in radiotherapy are expected to assess clinical acceptability of these tools. However, what is 'clinical acceptability'? Quantitative and qualitative approaches have been used to assess this ill-defined concept, all of which have advantages and disadvantages or limitations. The approach chosen may depend on the goal of the study as well as on available resources.
View Article and Find Full Text PDFPurpose: Deep-learning (DL) techniques have been successful in disease-prediction tasks and could improve the prediction of mandible osteoradionecrosis (ORN) resulting from head and neck cancer (HNC) radiation therapy. In this study, we retrospectively compared the performance of DL algorithms and traditional machine-learning (ML) techniques to predict mandible ORN binary outcome in an extensive cohort of patients with HNC.
Methods And Materials: Patients who received HNC radiation therapy at the University of Texas MD Anderson Cancer Center from 2005 to 2015 were identified for the ML (n = 1259) and DL (n = 1236) studies.
Launched in 2019, the French Citizens' Convention for Climate (CCC) tasked 150 randomly chosen citizens with proposing fair and effective measures to fight climate change. This was to be fulfilled through an "innovative co-construction procedure", involving some unspecified external input alongside that from the citizens. Did inputs from the steering bodies undermine the citizens' accountability for the output? Did co-construction help the output resonate with the general public, as is expected from a citizens' assembly? To answer these questions, we build on our unique experience in observing the CCC proceedings and documenting them with qualitative and quantitative data.
View Article and Find Full Text PDFThis study examined how major health organizations use Twitter for disseminating health information, building relationships, and encouraging actions to improve health. The sampled organizations were the American Heart Association, American Cancer Society, and American Diabetes Association. A content analysis was conducted on 1,583 tweets to examine these organizations' use of Twitter's interactive features and to understand the message functions and topics of their tweets.
View Article and Find Full Text PDFObjectives: To evaluate the accuracy, precision, and trending of a new endotracheally sourced impedance cardiography-based cardiac output (CO) monitor (ECOM; ConMed Corp, Irvine, CA).
Setting: Two university hospitals.
Participants: Thirty patients scheduled for elective coronary artery bypass graft (CABG) surgery.
This study proposes a health socialization model and applies it to examine direct, relative and mediating roles of interpersonal and media health socialization agents in predicting adolescent self-reported health literacy. We conducted a paper-and-pencil survey among 452 seventh graders in rural and urban school districts. Our regression analysis results show that both interpersonal and media socialization agents are significantly and positively related to adolescent health literacy.
View Article and Find Full Text PDFThis study explored health organizations' public relations efforts to frame health issues through their press releases. Content analysis of 316 press releases from three health organizations-the American Heart Association, the American Cancer Society, and the American Diabetes Association-revealed that they used the medical research frame most frequently and emphasized societal responsibility for health issues. There were differences, however, among the organizations regarding the main frames and health issues: the American Diabetes Association was more likely to focus on the issues related to social support and education, while the American Heart Association and the American Cancer Society were more likely to address medical research and scientific news.
View Article and Find Full Text PDFCell Mol Biol (Noisy-le-grand)
December 2003
Single nucleotide polymorphisms (SNPs) in the gene encoding the interleukin-4 receptor alpha chain (IL-4R alpha) have been associated with IgE levels or clinical atopy in some populations. Two SNPs that encode S503P and Q576R in the intracytoplasmic domain of the receptor are associated with loss or gain of function, respectively. We investigated the frequency of these SNPs and their association with traits of allergic asthma in 36 unrelated subjects selected from a racially admixed, clinically ascertained study population with family histories of asthma.
View Article and Find Full Text PDFDuring development and regeneration of the nervous system, growth cones of the various nerve cells navigate and direct neurite elongation by detecting and responding to cues in the environment. To investigate changes in growth cone behaviour due to calcium influx we used nerve growth factor (NGF)-induced growth cones of PC12 (rat pheochromocytoma cells) cells as a model. High external concentrations of potassium and ATP depress growth cone motility, induce club-shaped growth cones and reduce filopodia length and the number and relative F-actin contents of single growth cones (r.
View Article and Find Full Text PDFAnnexin I is an intracellular protein in search of a function. Ex vivo it has calcium- and phospholipid-binding properties. To evaluate its role in vivo, MCF-7 cells were stably transfected with annexin I in sense or antisense orientations.
View Article and Find Full Text PDFGrowth cones are known as the site of action of many factors that influence neurite growth behavior. To assess how different collapsing agents influence the growth cone cytoskeleton, we used recombinant human Semaphorin III (hSema III) and the serine protease thrombin. Embryonic chick dorsal root ganglion neurons showed a dramatic depolymerization of actin filaments within 5 min upon hSema III exposure and virtually no influence on microtubules (MT).
View Article and Find Full Text PDFGrowth cones at distal ends of elongating neurites are characterized by a bunch of motile filopodia. Filamentous actin (F-actin) is the supporting cytoskeletal structure of growth cone filopodia. Normal growth cone motility requires balanced polymerization and depolymerization rates of F-actin.
View Article and Find Full Text PDFPathfinding of growing nerve processes is guided by extracellular guidance cues. Here we report growth cone collapse of NGF-differentiated PC12 cells in culture evoked by the neuropeptide bradykinin. The growth cone response is mediated by B2 bradykinin receptors.
View Article and Find Full Text PDFPflugers Arch
September 1996
Bradykinin and caffeine were used as two different agonists to study inositol 1,4,5-trisphosphate (IP3)-sensitive and caffeine/ryanodine-sensitive intracellular Ca2+ release in the outgrowing neurites of nerve-growth-factor (NGF)-treated rat phaeochromocytoma cells (PC12). Changes in neuritic intracellular free Ca2+ ([Ca2+]i) in single cells were measured after loading with a 1:1 mixture of the acetoxymethyl (AM) ester of the Ca2+-sensitive dyes Fura-red and Fluo-3, in combination with confocal microscopy. Bradykinin-induced Ca2+ release was blocked by U73211, a specific phospholipase C inhibitor.
View Article and Find Full Text PDFVoltage-gated sodium channels in brain neurons are complexes of a pore-forming alpha subunit with smaller beta 1 and beta 2 subunits. cDNA cloning and sequencing showed that the beta 2 subunit is a 186 residue glycoprotein with an extracellular NH2-terminal domain containing an immunoglobulin-like fold with similarity to the neural cell adhesion molecule (CAM) contactin, a single transmembrane segment, and a small intracellular domain. Coexpression of beta 2 with alpha subunits in Xenopus oocytes increases functional expression, modulates gating, and causes up to a 4-fold increase in the capacitance of the oocyte, which results from an increase in the surface area of the plasma membrane microvilli.
View Article and Find Full Text PDFRat pheochromocytoma (PC12) cells were treated with nerve growth factor (NGF) for 3-4 days. They formed growth cones and extended neurites. Addition of the phosphatase inhibitor calyculin A (CL-A) caused a concentration-dependent complete retraction of neurites within 15 min.
View Article and Find Full Text PDFWe have studied the effects of protein kinase C (PKC) activators 4 beta-phorbol 12-myristate 13-acetate (4 beta-PMA) and 1-oleoyl-2-acetylglycerol (OAG) and of phosphatase inhibitors (okadaic acid and calyculin A) on voltage-activated Ca2+ and K+ channels in nerve-growth-factor-(NGF)-differentiated pheochromocytoma (PC12) cells. Whole-cell Ba2+ and K+ currents were recorded at room temperature with the patch-clamp technique. By using omega-conotoxin (CgTX) and isradipine, two specific Ca2+ channel blockers, we found three types of Ba2+ currents (IBa): (1) a omega-CgTX-sensitive IBa; (2) an isradipine-sensitive IBa; and (3) a omega-CgTX plus isradipine-resistant IBa.
View Article and Find Full Text PDF1. A clone of the rat phaeochromocytoma cell line (PC12) was treated with nerve growth factor (NGF) for 4-6 days and used to study caffeine- and bradykinin-induced Ca2+ release from intracellular Ca2+ stores. The caffeine-sensitive store can be depleted by Ca(2+)-induced Ca2+ release (CICR), while the bradykinin-induced release is mediated by inositol 1,4,5-trisphosphate (IP3).
View Article and Find Full Text PDFWe have studied morphological differentiation and ion channel expression in PC12 cells under different culture conditions. Differentiation mediated by nerve growth factor (NGF) was compared with that induced by depletion and inhibition of protein kinases (phorbol ester beta-PMA plus staurosporine). Morphological differentiation was similar under both conditions.
View Article and Find Full Text PDFThe calmodulin inhibitor 1,3-dihydro-1-[1-((4-methyl-4H,6H-pyrrolo[1,2-a]-[4,1]benzoxazepin - 4-yl)methyl)-4-piperidinyl]-2H-benzimidazol-2-one maleate (CGS 9343B) caused a reversible block of voltage-activated Ca2+, Na+, and K+ currents in differentiated rat pheochromocytoma (PC12) cells. The drug also inhibited nicotinic acetylcholine receptor (nAChR) channel currents but not inward currents evoked by extracellular ATP. Depolarization-induced intracellular Ca2+ transients were almost completely inhibited in growth cones and cell bodies by CGS 9343B.
View Article and Find Full Text PDFVoltage-sensitive sodium channels are responsible for the initiation and propagation of the action potential and therefore are important for neuronal excitability. Complementary DNA clones encoding the beta 1 subunit of the rat brain sodium channel were isolated by a combination of polymerase chain reaction and library screening techniques. The deduced primary structure indicates that the beta 1 subunit is a 22,851-dalton protein that contains a single putative transmembrane domain and four potential extracellular N-linked glycosylation sites, consistent with biochemical data.
View Article and Find Full Text PDFWe have studied the pathways by which extracellular bradykinin and adenosine 5'-triphosphate (ATP) elicit changes in intracellular free calcium ([Ca2+]i) in nerve-growth-factor(NGF)- treated rat pheochromocytoma (PC 12) cells. Both substances caused a significant rise in [Ca2+]i as assessed by fura-2 based microfluorimetry. The bradykinin-induced response consisted of an initial Ca2+ mobilization from an internal pool followed by a sustained increase in [Ca2+]i, which was due to activation of a small inward current.
View Article and Find Full Text PDFMembrane currents activated by bradykinin (500 nM) and by extracellular ATP (50 microM) were studied in voltage-clamped, NGF-treated rat pheochromocytoma (PC12) cells. Under quasiphysiological ionic conditions, both substances caused an outward current due to opening of Ca(2+)-activated K+ channels. Bradykinin caused an additional inward current that could be studied after blockade by internal Cs+ of the initial transient outward current.
View Article and Find Full Text PDF1. The rat clonal pheochromocytoma cell line (PC12) was used to study changes in the free intracellular Ca2+ concentration [( Ca2+]i) that are related to the distribution of L-type (dihydropyridine-sensitive) and N-type (omega-conotoxin-sensitive) calcium channels during nerve growth factor (NGF)-induced outgrowth of neurites. Changes in [Ca2+]i during K+ depolarization were recorded by means of Fura-2 single-cell microfluorimetry.
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