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BACKGROUND: Errors may occur during regional anaesthesia whilst searching for nerves, needle tips, and test doses. Poor visual search impacts on decision making, clinical intervention, and patient safety. METHODS: We conducted a randomised single-blind study in a single university hospital. Twenty trainees and two consultants examined the paired B-mode and fused B-mode and elastography video recordings of 24 interscalene and 24 femoral blocks conducted on two soft embalmed cadavers. Perineural injection was randomised equally to 0.25, 0.5, and 1.0 ml volumes. Tissue displacement perceived on both imaging modalities was defined as 'target' or 'distractor'. Our primary objective was to test the anaesthetists' perception of the number and proportion of targets and distractors on B-mode and fused elastography videos collected during femoral and sciatic nerve block on soft embalmed cadavers. Our secondary objectives were to determine the differences between novices and experts, and between test-dose volumes, and to measure the area and brightness of spread and strain patterns. RESULTS: All anaesthetists recognised perineural spread using 0.25 ml volumes. Distractor patterns were recognised in 133 (12%) of B-mode and in 403 (38%) of fused B-mode and elastography patterns; P<0.001. With elastography, novice recognition improved from 12 to 37% (P<0.001), and consultant recognition increased from 24 to 53%; P<0.001. Distractor recognition improved from 8 to 31% using 0.25 ml volumes (P<0.001), and from 15 to 45% using 1 ml volumes (P<0.001). CONCLUSIONS: Visual search improved with fusion elastography, increased volume, and consultants. A need exists to investigate image search strategies.
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Anestesistas/estatística & dados numéricos , Competência Clínica/estatística & dados numéricos , Bloqueio Nervoso/métodos , Ultrassonografia de Intervenção , Percepção Visual , Cadáver , Nervo Femoral , Humanos , Método Simples-CegoRESUMO
Neutrophils form the first line of defense of the innate immune system and are rapidly recruited by chemotactic signals to sites of inflammation. Understanding the mechanisms of neutrophil chemotaxis is therefore of great interest for the potential development of new immunoregulatory therapies. It has been shown that members of the transient receptor potential (TRP) family of cation channels are involved in both cell migration and chemotaxis. In this study, we demonstrate that TRPC1 channels play an important role in fMLP mediated chemotaxis and migration of murine neutrophils. The knock-out of TRPC1 channels leads to an impaired migration, transmigration and chemotaxis of the neutrophils. In contrast, Ca²âº influx but not store release after activation of the TRPC1(-/-) neutrophils with fMLP is strongly enhanced. We show that the enhanced Ca²âº influx in the TRPC1(-/-) neutrophils is associated with a steepened front to rear gradient of the intracellular Ca²âº concentration with higher levels at the cell rear. Taken together, this paper highlights a distinct role of TRPC1 in neutrophil migration and chemotaxis. We propose that TRPC1 controls the activity of further Ca²âº influx channels and thus regulates the maintenance of intracellular Ca²âº gradients which are critical for cell migration. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
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Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Quimiotaxia/efeitos dos fármacos , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Sinalização do Cálcio/genética , Quimiotaxia/genética , Camundongos , Camundongos Knockout , Neutrófilos/citologia , Canais de Cátion TRPC/genéticaRESUMO
In the recent decades, ion channels became the focus of cancer biologists, as many channels are overexpressed in tumour tissue and functionally they are linked to abnormal cell behaviour with processes including apoptosis, chemo- and radioresistance, proliferation and migration. KCa3.1 is a Ca2+-activated K+ channel that plays a central role in tumour progression in many cancer types. Therefore, the aim of the present study was to investigate KCa3.1 expression in pancreatic cancer cells and assess possible implications to disease progression. Using qPCR technique, we found abundant expression of KCa3.1 in pancreatic cancer cell lines. Patch clamp measurements on MiaPaCa-2 cells revealed a Ca2+-activated K+ current that matched biophysical characteristics as described for KCa3.1. Moreover, the current was sensitive to the commonly used channel modulators TRAM-34, clotrimazole and DC-EBIO, and it was abolished following transient gene knockdown of KCa3.1. We utilized both pharmacology and RNAi to assess a possible role of the channel in tumour cell behaviour. We found that the channel supported MiaPaCa-2 cell proliferation. Using RNAi protocols, we also identified KCa3.1 as important entity in cell invasion. However, TRAM-34 had unexpected stimulatory effects on cell migration and invasion estimated in various assays. Moreover, TRAM-34 increased intracellular Ca2+. In conclusion, we found prominent functional expression of KCa3.1 in pancreatic cancer cells. We provide evidence that the channel has a key role in cell proliferation and for the first time identify KCa3.1 as important entity in PDAC cell migration. We further reveal anomalous effects of TRAM-34.
Assuntos
Adenocarcinoma/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Neoplasias Pancreáticas/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Pirazóis/farmacologia , Potenciais de Ação , Benzimidazóis/farmacologia , Cálcio/metabolismo , Linhagem Celular Tumoral , Clotrimazol/farmacologia , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/antagonistas & inibidores , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genéticaRESUMO
The altered expression and/or activity of ion channels and transporters (transportome) have been associated with malignant behavior of cancer cells and were proposed to be a hallmark of cancer. However, the impact of altered transportome in epithelial cancers, such as pancreatic ductal adenocarcinoma (PDAC), as well as its pathophysiological consequences, still remains unclear. Here, we report the in silico analysis of 840 transportome genes in PDAC patients' tissues. Our study was focused on the transportome changes and their correlation with functional and behavioral responses in PDAC tumor and stromal compartments. The dysregulated gene expression datasets were filtered using a cut-off of fold-change values ≤-2 or ≥2 (adjusted p value ≤0.05). The dysregulated transportome genes were clearly associated with impaired physiological secretory mechanisms and/or pH regulation, control of cell volume, and cell polarity. Additionally, some down-regulated transportome genes were found to be closely linked to epithelial cell differentiation. Furthermore, the observed decrease in genes coding for calcium and chloride transport might be a mechanism for evasion of apoptosis. In conclusion, the current work provides a comprehensive overview of the altered transportome expression and its association with predicted PDAC malignancy with special focus on the epithelial compartment.
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Adenocarcinoma/metabolismo , Biologia Computacional , Simulação por Computador , Perfilação da Expressão Gênica , Canais Iônicos/genética , Canais Iônicos/metabolismo , Neoplasias Pancreáticas/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Epitélio/metabolismo , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Microambiente TumoralRESUMO
BACKGROUND: The incidence of intraneural injection during trainee anaesthetist ultrasound guided nerve block varies between 16% in experts and up to 35% in trainees. We hypothesized that elastography, an ultrasound-based technology that presents colour images of tissue strain, had the potential to improve trainee diagnosis of intraneural injection during UGRA, when integrated with B-Mode ultrasound onto a single image. METHODS: We recorded 40 median nerve blocks randomly allocated to 0.25 ml, 0.5 ml, 1 ml volumes to five sites, on both arms of two soft embalmed cadavers, using a dedicated B-Mode ultrasound and elastography transducer. We wrote software to fuse elastogram and B-Mode videos, then asked 20 trainee anaesthetists whether injection was intraneural or extraneural when seeing B-Mode videos, adjacent B-Mode and elastogram videos, fusion elastography videos or repeated B-Mode ultrasound videos. RESULTS: Fusion elastography improved the diagnosis of intraneural injection compared with B-Mode ultrasound, Diagnostic Odds Ratio (DOR) (95%CI) 21.7 (14.5 - 33.3) vs DOR 7.4 (5.2 - 10.6), P < 0.001. Compared with extraneural injection, intraneural injection was identified on fusion elastography as a distinct, brighter translucent image, geometric ratio 0.33 (95%CI: 0.16 - 0.49) P < 0.001. Fusion elastography was associated with greater trainee diagnostic confidence, OR (95%CI) 1.89 (1.69 - 2.11), P < 0.001, and an improvement in reliability, Kappa 0.60 (0.55 - 0.66). CONCLUSIONS: Fusion elastography improved the accuracy, reliability and confidence of trainee anaesthetist diagnosis of intraneural injection.
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Anestesistas/educação , Anestesistas/estatística & dados numéricos , Competência Clínica/estatística & dados numéricos , Técnicas de Imagem por Elasticidade/métodos , Nervo Mediano/diagnóstico por imagem , Bloqueio Nervoso/métodos , Ultrassonografia de Intervenção/métodos , Cadáver , Humanos , Nervo Mediano/efeitos dos fármacos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Early diagnosis and treatment of intracranial hypertension (ICHT) are major components of the management of neurological emergencies. The optic nerve sheath diameter is closely dependent on intracranial pressure and can be measured by bedside ultrasound (US). We report the story of a 70-year-old COPD patient initially admitted to the emergency room for a sepsis of pulmonary origin. An unusual confusion prompted us to perform an US of the optic nerve sheath. This exam clearly suggested the presence of an ICHT. Hence, the diagnostic approach was proceeded and a herpetic encephalitis was demonstrated and successfully treated. In this clinical report, the optic nerve sheath US guided the diagnostic approach and, eventually, therapeutic decision. Several papers have shown the close relationship between increased optic nerve sheath diameter and intracranial hypertension, but we still need further studies to validate a threshold value of this diameter. The clinical relevance of the US optic nerve diameter measure appears interesting. However, further studies on larger samples of patients are needed to confirm this and to establish a validated threshold value.
La précocité du diagnostic et du traitement de l'hypertension intracrânienne (HTIC) est un élément majeur de la prise en charge des pathologies neurologiques aux urgences. Le diamètre de la gaine des nerfs optiques est le reflet direct de la pression intracrânienne et peut être mesuré à l'aide de l'échographie au lit du patient. Nous relatons le cas d'un patient de 70 ans, initialement pris en charge pour un sepsis d'origine pulmonaire dans un contexte de BPCO, et chez qui une confusion inhabituelle a mené à la réalisation d'une échographie de la gaine des nerfs optiques. Celle-ci ayant mis en évidence une HTIC, la démarche diagnostique a été poussée plus en avant et une encéphalite zostérienne a été mise en évidence et traitée précocement avec efficacité. Dans ce cas clinique, l'échographie des nerfs optiques occupe une place prépondérante dans la démarche diagnostique et thérapeutique. L'efficacité de la mesure de la gaine des nerfs optiques pour diagnostiquer une HTIC est démontrée; cependant, il n'existe pas, à l'heure actuelle, de consensus sur une valeur «seuil¼ de diamètre de la gaine. De nouvelles études sont nécessaires pour préciser ce paramètre.
Assuntos
Hipertensão Intracraniana/diagnóstico por imagem , Nervo Óptico/diagnóstico por imagem , Idoso , Serviço Hospitalar de Emergência , Humanos , Pressão Intracraniana , UltrassonografiaRESUMO
BACKGROUND: hERG1 channels are aberrantly expressed in human cancers. The expression, functional role and clinical significance of hERG1 channels in pancreatic ductal adenocarcinoma (PDAC) is lacking. METHODS: hERG1 expression was tested in PDAC primary samples assembled as tissue microarray by immunohistochemistry using an anti-hERG1 monoclonal antibody (α-hERG1-MoAb). The functional role of hERG1 was studied in PDAC cell lines and primary cultures. ERG1 expression during PDAC progression was studied in Pdx-1-Cre,LSL-Kras(G12D/+),LSL-Trp53(R175H/+) transgenic (KPC) mice. ERG1 expression in vivo was determined by optical imaging using Alexa-680-labelled α-hERG1-MoAb. RESULTS: (i) hERG1 was expressed at high levels in 59% of primary PDAC; (ii) hERG1 blockade decreased PDAC cell growth and migration; (iii) hERG1 was physically and functionally linked to the Epidermal Growth Factor-Receptor pathway; (iv) in transgenic mice, ERG1 was expressed in PanIN lesions, reaching high expression levels in PDAC; (v) PDAC patients whose primary tumour showed high hERG1 expression had a worse prognosis; (vi) the α-hERG1-MoAb could detect PDAC in vivo. CONCLUSIONS: hERG1 regulates PDAC malignancy and its expression, once validated in a larger cohort also comprising of late-stage, non-surgically resected cases, may be exploited for diagnostic and prognostic purposes in PDAC either ex vivo or in vivo.
Assuntos
Carcinoma Ductal Pancreático/metabolismo , Canais de Potássio Éter-A-Go-Go/metabolismo , Neoplasias Pancreáticas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Canal de Potássio ERG1 , Receptores ErbB/genética , Receptores ErbB/metabolismo , Canais de Potássio Éter-A-Go-Go/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Camundongos Transgênicos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , PrognósticoRESUMO
Members of the TMEM16 family have recently been described as Ca(2+)-activated Cl(-) channels. They have been implicated in cancer and appear to be associated with poor patient prognosis. Here, we investigate the role of TMEM16 channels in cell migration, which is largely unknown. We focused on TMEM16A and TMEM16F channels that have the highest expression of TMEM16 channels in Ehrlich Lettre ascites (ELA) cells. Due to the lack of specific pharmacological modulators, we employed a miRNA approach and stably knocked down the expression of TMEM16A and TMEM16F channels, respectively. Migration analysis shows that TMEM16A KD clones are affected in their directional migration, whereas TMEM16F KD clones show a 40 % reduced rate of cell migration. Moreover, TMEM16A KD clones have a smaller projected cell area, and they are rounder than TMEM16F KD clones. The morphological changes are linearly correlated with the directionality of cells. TMEM16A and TMEM16F, thus, have an important function in cell migration-TMEM16A in directional migration, TMEM16F in determination of the speed of migration. We conclude that TMEM16A and TMEM16F channels have a distinct impact on the steering and motor mechanisms of migrating ELA cells.
Assuntos
Movimento Celular/fisiologia , Canais de Cloreto/fisiologia , Proteínas de Transferência de Fosfolipídeos/fisiologia , Animais , Anoctamina-1 , Anoctaminas , Carcinoma de Ehrlich , Técnicas de Silenciamento de Genes , CamundongosRESUMO
Ultrasound guidance is now common in regional anaesthesia practice, but remains limited by poor visibility of the needle tip and poor quantification of local anaesthetic spread. Sonoelastography based on tissue compression is a technique depicting tissue strain. Hitherto used largely for tumour diagnosis, we used it in both Thiel embalmed cadavers and two patients receiving interscalene and femoral blocks to observe changes in tissue strain during local anaesthetic injection. The primary aim of our study was to measure the area under the curve (weighted for time) of the strain pattern in Thiel perineural tissue when using a range of volumes of embalming fluid (0.25, 0.5, 1, 2.5, 5 and 7.5 ml) for interscalene and femoral blocks using sonoelastography. Our secondary aims were to evaluate static images of anatomy and videos of needle insertion and perineural injection using combined B-Mode ultrasound and sonoelastography. Independent raters assessed the anatomy and spread using a 7-point Likert scale, ranked from extremely poor to extremely good. We performed 83 blocks in cadavers. Concordance between both raters was good, with weighted Kappa (95% CI) 0.66 (0.61-0.71). The characteristics of spread were similar with both interscalene and femoral block; spread increased with injectate volume up to 1 ml. Analysis of variance showed differences in spread between injection volumes (p = 0.009), but not between regional blocks (p = 0.05). Post-hoc analysis showed greater spread with 1 and 2.5 ml volumes compared with 0.25 ml. In patients, visibility of strain during injection was better with sonoelastography than with B-Mode ultrasound and showed a dose response from 1 to 5 ml volumes of local anaesthetic. Colour strain recognition using sonoelastography offers the ability to differentiate between nerve and surrounding tissue during local anaesthetic injection by improving visibility of spread (p = 0.04).
Assuntos
Técnicas de Imagem por Elasticidade/métodos , Bloqueio Nervoso/métodos , Ultrassonografia de Intervenção/métodos , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais/administração & dosagem , Anestésicos Locais/farmacocinética , Plexo Braquial/diagnóstico por imagem , Cadáver , Relação Dose-Resposta a Droga , Embalsamamento/métodos , Feminino , Nervo Femoral/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Raízes Nervosas Espinhais/diagnóstico por imagemRESUMO
Staphylococcus aureus (n=157) isolated from intramammary infections in Argentine dairy areas were evaluated for presence of cap5 and cap8 loci. Isolates carrying cap5 and cap8 were serotyped using specific antisera. Sixty four percent of the isolates were genotyped as cap5 or cap8 and 50% of them expressed CP5 or 8.
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Hydrated lime is widely used as a mineral filler to improve several properties of bituminous materials such as reducing the susceptibility of the composite to moisture-induced damage. Although experimental evidence supports the efficacy of using hydrated lime as a mineral filler, the molecular scale mechanism of reactivity of hydrated lime within the bitumen to reduce moisture damage is not understood. This is important when considering the durability of structural applications of bituminous materials such as asphalt concrete pavements subjected to both environmental and loading extremes. In this study, the interaction between hydrated lime and the key molecular building blocks of bitumen is modeled using density functional theory and compared against analogues of other common fillers such as calcite and quartz. Free energies of dissociation (ΔG dissoc) are calculated, and the nature of the bonds is characterized with contour maps of the Laplacian of the electron density. Hydrated lime is capable of reacting with specific functional groups in bitumen moieties and developing strong, water-resistant complexes. Among the functional groups investigated, carboxylic acids are the preferential reaction sites between hydrated lime and the bitumen moieties. Values as high as ΔG dissoc = +49.42 kcal/mol are reported for hydrated lime with water as the surrounding solvent. In contrast, analogues of calcite (ΔG dissoc = +15.84 kcal/mol) and quartz (ΔG dissoc = +4.76 kcal/mol) are unable to chemically react as strongly as hydrated lime in the presence of water. Contour maps of the Laplacian of the electron density indicate that the bonds between hydrated lime and model asphalt moieties are of an ionic nature. The atomistic modeling results correlate with thermodynamic calculations derived from experimental constants and are consistent with infrared spectrometric data.
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The adsorption characteristics of an iron cyanide complex, soluble Prussian blue KFe(III)[Fe(II)(CN)(6)], were evaluated for representative soil minerals and soil at pH 3.7, 6.4 and 9.7. Three specimen clay minerals (kaolinite, montmorillonite, and illite), two synthesized manganese oxides (birnessite and cryptomelane), and a Drummer soil from Indiana were used as the adsorbents. Surface protonation of variable charge sites increased with decreasing pH yielding positively charged sites on crystal edges and enhancing the attractive force between minerals and iron cyanide complexes. Anion adsorption on clays often is correlated to the metal content of the adsorbent, and a positive relationship was observed between iron or aluminum content and Prussian blue adsorption. Illite had high extractable iron and adsorbed more ferro-ferricyande anion, while kaolinite and montmorillonite had lower extractable iron and adsorbed less. However, less pH effect was observed on the adsorption of iron cyanide to manganese oxides. This may due to the manganese oxide mediated oxidation of ferrocyanide [Fe(II)(CN)(6)(4-)], to ferricyanide [Fe(III)(CN)(6)(3-)], which has a low affinity for manganese oxides.
Assuntos
Silicatos de Alumínio/química , Ferricianetos/química , Resíduos Perigosos , Compostos de Manganês/química , Óxidos/química , Poluentes do Solo/química , Adsorção , Argila , Concentração de Íons de Hidrogênio , SoloRESUMO
Biofabrication is providing scientists and clinicians the ability to produce engineered tissues with desired shapes and gradients of composition and biological cues. Typical resolutions achieved with extrusion-based bioprinting are at the macroscopic level. However, for capturing the fibrillar nature of the extracellular matrix (ECM), it is necessary to arrange ECM components at smaller scales, down to the micron and the molecular level. Herein, we introduce a bioink containing the tyramine derivative of hyaluronan (HA; henceforth known as THA) and collagen (Col) type 1. In this bioink, similar to connective tissues, Col is present in the fibrillar form, and HA functions as a viscoelastic space filler. THA was enzymatically cross-linked under mild conditions allowing simultaneous Col fibrillogenesis, thus achieving a homogeneous distribution of Col fibrils within the viscoelastic HA-based matrix. The THA-Col composite displayed synergistic properties in terms of storage modulus and shear thinning, translating into good printability. Shear-induced alignment of the Col fibrils along the printing direction was achieved and quantified via immunofluorescence and second-harmonic generation. Cell-free and cell-laden constructs were printed and characterized, analyzing the influence of the controlled microscopic anisotropy on human bone marrow-derived mesenchymal stromal cell (hMSC) migration. Anisotropic HA-Col showed cell-instructive properties modulating hMSC adhesion, morphology, and migration from micropellets stimulated by the presence and the orientation of Col fibers. Actin filament staining showed that hMSCs embedded in aligned constructs displayed increased cytoskeleton alignment along the fibril direction. Based on gene expression of cartilage/bone markers and ECM production, hMSCs embedded in the isotropic bioink displayed chondrogenic differentiation comparable with standard pellet culture by means of proteoglycan production (safranin O staining and proteoglycan quantification). The possibility of printing matrix components with control over microscopic alignment brings biofabrication one step closer to capturing the complexity of native tissues.
RESUMO
Two views dealing with fish welfare in recreational fishing are discussed in an effort to stimulate the current discourse on the topic. The pragmatic approach asks whether and how strongly recreational fishing compromises the health and fitness of individual fishes and what can be done to avoid or mitigate such effects. Its implementation rests on accepting recreational fishing as a principally legitimate activity. The second approach to fish welfare focuses on suffering and pain in fishes and is usually morally prescriptive. Its central tenet is that some or all recreational fishing practices may be unacceptable unless sufficient benefits to humans are created, which justify the supposedly cruel treatment of the fishes. The pragmatic approach to fish welfare is preferred because it relies on objectively measurable variables of impaired fish welfare (e.g. physiological, behavioural or fitness indicators) and does not question recreational fishing on moral grounds. Contrary to a suffering-centred approach to fish welfare, a pragmatic perspective emphasizes positive messages and facilitates constructive dialogue among stakeholders. In contrast, a suffering-centred approach to fish welfare tends to promote tension and enduring conflict that cannot be reconciled objectively and thus should be avoided.
Assuntos
Bem-Estar do Animal , Peixes/fisiologia , Recreação , Estresse Psicológico , Animais , HumanosRESUMO
Melanoma incidence is on the rise and currently causes the majority of skin cancer-related deaths. Yet, therapies for metastatic melanoma are still insufficient so that new concepts are essential. Malignant transformation of melanocytes and melanoma progression are intimately linked to the cutaneous pH landscape and its dysregulation in tumour lesions. The pH landscape of normal skin is characterized by a large pH gradient of up to 3 pH units between surface and dermis. The Na+ /H+ exchanger NHE1 is one of the major contributors of acidity in superficial skin layers. It is also activated by the most frequent mutation in melanoma, BRAFV600E , thereby causing pH dysregulation during melanoma initiation. Melanoma progression is supported by an extracellular acidification and/or NHE1 activity which promote the escape of single melanoma cells from the primary tumour, migration and metastatic spreading. We propose that viewing melanoma against the background of the acid-base physiology of the skin provides a better understanding of the pathophysiology of this disease and allows the development of novel therapeutic concepts.
Assuntos
Melanoma/metabolismo , Neoplasias Cutâneas/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Melanoma/etiologia , Mutação , Neoplasias Cutâneas/etiologia , Trocador 1 de Sódio-Hidrogênio/genética , Trocador 1 de Sódio-Hidrogênio/metabolismoRESUMO
Greenhouse and field studies were conducted to evaluate the feasibility of phytoremediation for clean-up of highly contaminated sediments from Indiana Harbor. In the greenhouse study, plant species evaluated were willow (Salix exigua), poplar (Populus spp.), eastern gamagrass (Tripsacum dactyloides), arrowhead (Sagitaria latifolia), switchgrass (Panicum virgatum), and sedge (Carex stricta). Sediments with sedge, switchgrass, and gamagrass had significantly less residual total petroleum hydrocarbons (TPH) after one year of growth (approximately 70% reduction) than sediments containing willow, poplar, or no plants (approximately 20% reduction). Although not all polycyclic aromatic hydrocarbons (PAH) had concentration differences due to the presence of plants, residual pyrene concentrations in the unvegetated pots were significantly higher than in pots containing sedge, switchgrass, arrowhead, and gamagrass. As evaluated by TPH dissipation in the upper section of the pots, the sedge, switchgrass, and gamagrass treatments had higher TPH degradation than the unvegetated, willow and poplar treatments. These trends were similar for soil at the bottom of the pots, with the exception that in the switchgrass treatment, degradation was not significantly different than in the unvegetated soil. Two target contaminants, pyrene and benzo[b]fluoranthene, showed differences in degradation between planted and unvegetated treatments. In the field study, phytoremediation plant species were eastern gamagrass (T. dactyloides), switchgrass (P. virgatum), and sedge (C. stricta). In addition, rhizosphere characteristics of arrowhead (S. latifolia) and sedge were assessed. Arrowhead- and sedge-impacted soils were found to contain significantly more PAH-degrading bacteria than unvegetated soils. However, over the 12-month field study, no significant differences in contamination were found between the planted and unplanted soils for TPH and PAH concentrations. TPH concentrations near the canal were greater than concentrations further from the canal, indicating that the canal may have served as a continuous source of contamination during the study.
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Biodegradação Ambiental , Biotecnologia/métodos , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Biomassa , Cromatografia/métodos , Poluição Ambiental , Hidrocarbonetos , Microbiologia Industrial , Resíduos Industriais , Plantas , Solo , Microbiologia do Solo , Poluentes do SoloRESUMO
Remediation of soils containing high concentrations of polycyclic aromatic hydrocarbons (PAHs) seldom results in complete removal of contaminants, but residual toxicity often is reduced. In this study, soil from a former manufactured gas plant site was treated for 12 months by phytoremediation and then tested for total PAHs, Tenax-TA extractable ("labile") PAHs, aqueous soluble PAHs (PAH(wp)) , and biotoxicity assessed by earthworms survival, nematode mortality, emergence of lettuce seedlings, and microbial respiration. Prior to phytoremediation, the soil had toxic impacts on all bioassays (except the nematodes), and 12 months of remediation decreased this response. Change in labile PAHs was a predictor for change in total PAH for 3- and 4-ring compounds but not for the 5- and 6-ring. Decreases in labile PAHs were correlated (r(2)>or=0.80) with toxicity in the bioassays except microbial respiration. PAH(wp) was correlated only with nematode toxicity prior to remediation but with none of the tests after remediation. Total PAHs were not correlated with any of the bioassay tests. Tenax-TA appears to have potential for predicting residual toxicity in remediated soils and is superior to total concentrations for that application.