244 research outputs found
Pharmacological Or Genetic Targeting Of Transient Receptor Potential (TRP) Channels Can Disrupt The Planarian Escape Response
In response to noxious stimuli, planarians cease their typical ciliary gliding and exhibit an oscillatory type of locomotion called scrunching. We have previously characterized the biomechanics of scrunching and shown that it is induced by specific stimuli, such as amputation, noxious heat, and extreme pH. Because these specific inducers are known to activate Transient Receptor Potential (TRP) channels in other systems, we hypothesized that TRP channels control scrunching. We found that chemicals known to activate TRPA1 (allyl isothiocyanate (AITC) and hydrogen peroxide) and TRPV (capsaicin and anandamide) in other systems induce scrunching in the planarian species Dugesia japonica and, except for anandamide, in Schmidtea mediterranea. To confirm that these responses were specific to either TRPA1 or TRPV, respectively, we tried to block scrunching using selective TRPA1 or TRPV antagonists and RNA interference (RNAi) mediated knockdown. Unexpectedly, co-treatment with a mammalian TRPA1 antagonist, HC-030031, enhanced AITC-induced scrunching by decreasing the latency time, suggesting an agonistic relationship in planarians. We further confirmed that TRPA1 in both planarian species is necessary for AITC-induced scrunching using RNAi. Conversely, while co-treatment of a mammalian TRPV antagonist, SB-366791, also enhanced capsaicin-induced reactions in D. japonica, combined knockdown of two previously identified D. japonica TRPV genes (DjTRPVa and DjTRPVb) did not inhibit capsaicin-induced scrunching. RNAi of DjTRPVa/DjTRPVb attenuated scrunching induced by the endocannabinoid and TRPV agonist, anandamide. Overall, our results show that although scrunching induction can involve different initial pathways for sensing stimuli, this behavior’s signature dynamical features are independent of the inducer, implying that scrunching is a stereotypical planarian escape behavior in response to various noxious stimuli that converge on a single downstream pathway. Understanding which aspects of nociception are conserved or not across different organisms can provide insight into the underlying regulatory mechanisms to better understand pain sensation
Nanoparticle-labeled stem cells: a novel therapeutic vehicle
Nanotechnology has been described as a general purpose technology. It has already generated a range of inventions and innovations. Development of nanotechnology will provide clinical medicine with a range of new diagnostic and therapeutic opportunities such as medical imaging, medical diagnosis, drug delivery, and cancer detection and management. Nanoparticles such as manganese, polystyrene, silica, titanium oxide, gold, silver, carbon, quantum dots, and iron oxide have received enormous attention in the creation of new types of analytical tools for biotechnology and life sciences. Labeling of stem cells with nanoparticles overcame the problems in homing and fixing stem cells to their desired site and guiding extension of stem cells to specific directions. Although the biologic effects of some nanoparticles have already been assessed, information on toxicity and possible mechanisms of various particle types remains inadequate. The aim of this review is to give an overview of the mechanisms of internalization and distribution of nanoparticles inside stem cells, as well as the influence of different types of nanoparticles on stem cell viability, proliferation, differentiation, and cytotoxicity, and to assess the role of nanoparticles in tracking the fate of stem cells used in tissue regeneration
Bioactive compounds from Acokanthera oblongifolia
One cardiotonic glycoside, three triterpenes and one steroidal glycoside were isolated from Acokanthera oblongifolia fruits (pericarp) growing in Libya. Their structures were investigated by extensive application of IR, MS, 1DNMR and 2DNMR spectroscopy. The isolated compounds have evidenced in-vitro cytotoxicity on selected human cell lines (A-549, H-1299) when compared to doxorubicin. Keywords: Cardenolide; Acokanthera oblongifolia; antitumor activity; lung carcinoma cell line (A-549, H-1299)
Obtenção de hĂbridos de melĂŁo adaptados as condições da regiĂŁo Nordeste.
bitstream/CNPAT-2010/11937/1/Pa-042.pd
Melhoramento populacional do meloeiro para cultivo na RegiĂŁo Nordeste.
Este trabalho objetiva desenvolver e melhorar geneticamente populacoes de melao para os tipos de frutos rendilhado e amarelo, e adapta-las ao cultivo nas condicoes do Nordeste.bitstream/CNPAT-2010/5408/1/Pa-043.pd
A novel method to optimize autologous adipose tissue recovery with extracellular matrix preservation
This work aims to characterize a new method to recover low-manipulated human adipose tissue, enriched with adipose tissue-derived mesenchymal stem cells (ATD-MSCs) for autologous use in regenerative medicine applications. Lipoaspirated fat collected from patients was processed through Lipocell, a Class II-a medical device for dialysis of adipose tissue, by varying filter sizes and washing solutions. ATD-MSC yield was measured with flow cytometry after stromal vascular fraction (SVF) isolation in fresh and cultured samples. Purification from oil and blood was measured after centrifugation with spectrophotometer analysis. Extracellular matrix preservation was assessed through hematoxylin and eosin (H&E) staining and biochemical assay for total collagen, type-2 collagen, and glycosaminoglycans (GAGs) quantification. Flow cytometry showed a two-fold increase of ATD-MSC yield in treated samples in comparison with untreated lipoaspirate; no differences where reported when varying filter size. The association of dialysis and washing thoroughly removed blood and oil from samples. Tissue architecture and extracellular matrix integrity were unaltered after Lipocell processing. Dialysis procedure associated with Ringer’s lactate preserves the proliferation ability of ATD-MSCs in cell culture. The characterization of the product showed that Lipocell is an efficient method for purifying the tissue from undesired byproducts and preserving ATD-MSC vitality and extracellular matrix (ECM) integrity, resulting in a promising tool for regenerative medicine applications
A novel method to optimize autologous adipose tissue recovery with extracellular matrix preservation
This work aims to characterize a new method to recover low-manipulated human adipose tissue, enriched with adipose tissue-derived mesenchymal stem cells (ATD-MSCs) for autologous use in regenerative medicine applications. Lipoaspirated fat collected from patients was processed through Lipocell, a Class II-a medical device for dialysis of adipose tissue, by varying filter sizes and washing solutions. ATD-MSC yield was measured with flow cytometry after stromal vascular fraction (SVF) isolation in fresh and cultured samples. Purification from oil and blood was measured after centrifugationwith spectrophotometer analysis. Extracellularmatrix preservationwas assessed through hematoxylin and eosin (H&E) staining and biochemical assay for total collagen, type-2 collagen, and glycosaminoglycans (GAGs) quantification. Flow cytometry showed a two-fold increase of ATD-MSC yield in treated samples in comparisonwith untreated lipoaspirate; no differenceswhere reportedwhen varying filter size. The association of dialysis and washing thoroughly removed blood and oil from samples. Tissue architecture and extracellular matrix integrity were unaltered after Lipocell processing. Dialysis procedure associated with Ringer's lactate preserves the proliferation ability of ATD-MSCs in cell culture. The characterization of the product showed that Lipocell is an efficient method for purifying the tissue from undesired byproducts and preserving ATD-MSC vitality and extracellular matrix (ECM) integrity, resulting in a promising tool for regenerative medicine applications
Large scale analytic calculations in quantum field theories
We present a survey on the mathematical structure of zero- and single scale
quantities and the associated calculation methods and function spaces in higher
order perturbative calculations in relativistic renormalizable quantum field
theories.Comment: 25 pages Latex, 1 style fil
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