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Quantifying the links between the marine environment, prey occurrence, and predator distribution is the first step towards identifying areas of biological importance for marine spatial planning. Events such as marine heatwaves result in an anomalous change in the physical environment, which can lead to shifts in the structure, biomass, and distribution of lower trophic levels. As central-place foragers, seabirds are vulnerable to changes in their foraging grounds during the breeding season. We first quantified spatiotemporal variability in the occurrence and biomass of prey in response to an abrupt change in oceanography as a result of a marine heatwave event. Secondly, using multivariate techniques and machine learning, we investigated if differences in the foraging technique and prey of seabirds resulted in varying responses to changes in prey occurrence and the environment over a 2.5-yr period. We found that the main variables correlated with seabird distribution were also important in structuring the occurrence and biomass of prey; sea-surface temperature (SST), current speed, mixed-layer depth, and bathymetry. Both zooplankton biomass and the occurrence of fish schools exhibited negative relationships with temperature, and temperature was subsequently an important variable in determining seabird distribution. We were able to establish correlations between the distribution of prey and the spatiotemporal distribution of albatross, little penguins and common-diving petrels. We were unable to find a correlation between the distribution of prey and that of short-tailed shearwaters and fairy prions. For high-use coastal areas, the delineation of important foraging regions is essential to balance human use of an area with the needs of marine predators, particularly seabirds.
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Comportamento Predatório , Spheniscidae , Animais , Meio Ambiente , Peixes , Humanos , Estações do AnoRESUMO
INTRODUCTION: Patients with factitious disorder (FD) or "Munchausen syndrome" intentionally fabricate or induce medical problems for psychological gratification. They may deceive plastic surgeons into performing multiple unnecessary procedures. We undertook the first systematic review of FD case reports in plastic surgery. Our aims were 2-fold: (1) describe the adverse outcomes associated with these cases and (2) identify strategies for their prevention by surgeons. METHODS: MEDLINE, EMBASE, and SCOPUS databases were searched. We included cases in which an adult with FD presented to a plastic surgeon. Our search returned a total of 42 eligible cases reported from North America (43%), Europe (37%), and Asia (20%). RESULTS: Seventy-six percent of patients were women, and 62% worked in health care. Sixty percent had a comorbid psychiatric disorder, the most common (50%) being depression. Ninety-three percent of our sample presented with self-induced lesions. The average delay in diagnosis of FD was 54 months, with 46% of patients receiving multiple surgical procedures in this time, including debridement (36%) and skin grafts (39%). Surgical wounds were frequently exploited by patients to remain in, or return to, hospital: 50% contaminated or manipulated their wounds to prevent healing. Thirty-six percent of cases resulted in significant long-term disability (24%) or disfigurement (12%). Ten percent of patients received an amputation. Outcomes were improved when patients were confronted by surgeons, however, and 62% were willing to see a psychiatrist. Surgeons were able to support recovery in 33% of cases-for example, by using occlusive wound dressings. CONCLUSIONS: Patients with FD who present to plastic surgeons are high risk: the majority require surgical intervention for severe self-injury, and many engage in harmful behaviors, such as "doctor-shopping." Early recognition of FD in plastic surgery is, therefore, crucial and may be achieved via careful examination of lesions for unusual morphology. Medical records may reveal extensive health care service use and negative investigations. Finally, plastic surgeons may play an important role in managing such patients. Management strategies include direct observation by nursing staff in the postoperative period and use of strict occlusive dressings to prevent access to surgical wounds.
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Síndrome de Munchausen , Procedimentos de Cirurgia Plástica , Cirurgia Plástica , Adulto , Ásia , Europa (Continente) , Feminino , Humanos , Masculino , Síndrome de Munchausen/diagnósticoRESUMO
OBJECTIVE: Cortical gray matter (GM) pathology, involving demyelination and neurodegeneration, associated with meningeal inflammation, could be important in determining disability progression in multiple sclerosis (MS). However, we need to know more about how cortical demyelination, neurodegeneration, and meningeal inflammation contribute to pathology at early stages of MS to better predict long-term outcome. METHODS: Tissue blocks from short disease duration MS (n = 12, median disease duration = 2 years), progressive MS (n = 21, disease duration = 25 years), non-diseased controls (n = 11), and other neurological inflammatory disease controls (n = 6) were quantitatively analyzed by immunohistochemistry, immunofluorescence, and in situ hybridization. RESULTS: Cortical GM demyelination was extensive in some cases of acute MS (range = 1-48% of total cortical GM), and subpial lesions were the most common type (62%). The numbers of activated (CD68+ ) microglia/macrophages were increased in cases with subpial lesions, and the density of neurons was significantly reduced in acute MS normal appearing and lesion GM, compared to controls (p < 0.005). Significant meningeal inflammation and lymphoid-like structures were seen in 4 of 12 acute MS cases. The extent of meningeal inflammation correlated with microglial/macrophage activation (p < 0.05), but not the area of cortical demyelination, reflecting the finding that lymphoid-like structures were seen adjacent to GM lesions as well as areas of partially demyelinated/remyelinated, cortical GM. INTERPRETATION: Our findings demonstrate that cortical demyelination, neuronal loss, and meningeal inflammation are notable pathological hallmarks of acute MS and support the need to identify early biomarkers of this pathology to better predict outcome. Ann Neurol 2018;84:829-842.
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Córtex Cerebral/patologia , Inflamação/complicações , Meninges/patologia , Esclerose Múltipla/complicações , Bainha de Mielina/patologia , Adulto , Idoso , Antígenos CD/metabolismo , Córtex Cerebral/metabolismo , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Progressão da Doença , Feminino , Substância Cinzenta/metabolismo , Substância Cinzenta/patologia , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Meninges/metabolismo , Microglia/metabolismo , Microglia/patologia , Pessoa de Meia-Idade , Bainha de Mielina/metabolismo , Fatores de Transcrição/metabolismo , Adulto JovemRESUMO
BACKGROUND: CD59, a broadly expressed glycosylphosphatidylinositol-anchored protein, is the principal cell inhibitor of complement membrane attack on cells. In the demyelinating disorders, multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), elevated complement protein levels, including soluble CD59 (sCD59), were reported in cerebrospinal fluid (CSF). OBJECTIVES: We compared sCD59 levels in CSF and matched plasma in controls and patients with MS, NMOSD and clinically isolated syndrome (CIS) and investigated the source of CSF sCD59 and whether it was microparticle associated. METHODS: sCD59 was quantified using enzyme-linked immunosorbent assay (ELISA; Hycult; HK374-02). Patient and control CSF was subjected to western blotting to characterise anti-CD59-reactive materials. CD59 was localised by immunostaining and in situ hybridisation. RESULTS: CSF sCD59 levels were double those in plasma (CSF, 30.2 ng/mL; plasma, 16.3 ng/mL). Plasma but not CSF sCD59 levels differentiated MS from NMOSD, MS from CIS and NMOSD/CIS from controls. Elimination of microparticles confirmed that CSF sCD59 was not membrane anchored. CONCLUSION: CSF levels of sCD59 are not a biomarker of demyelinating diseases. High levels of sCD59 in CSF relative to plasma suggest an intrathecal source; CD59 expression in brain parenchyma was low, but expression was strong on choroid plexus (CP) epithelium, immediately adjacent the CSF, suggesting that this is the likely source.
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Antígenos CD59/líquido cefalorraquidiano , Plexo Corióideo/metabolismo , Doenças Desmielinizantes/líquido cefalorraquidiano , Esclerose Múltipla/líquido cefalorraquidiano , Neuromielite Óptica/líquido cefalorraquidiano , Adulto , Antígenos CD59/sangue , Doenças Desmielinizantes/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/sangue , Neuromielite Óptica/sangueRESUMO
'Modern' oral tobacco-free nicotine pouches (NPs) are a nicotine containing product similar in appearance and concept to Swedish snus. A three-step approach was taken to analyse the biological effects of NPs and snus extracts in vitro. ToxTracker was used to screen for biomarkers for oxidative stress, cell stress, protein damage and DNA damage. Cytotoxicity, mutagenicity, and genotoxicity were assessed in the following respective assays: Neutral Red Uptake (NRU), Ames and Mouse Lymphoma Assay (MLA). Targeted analysis of phosphorylation signalling and inflammatory markers under non-toxic conditions was used to investigate any potential signalling pathways or inflammatory response. A reference snus (CRP1.1) and four NPs with various flavours and nicotine strengths were assessed. Test article extracts was generated by incubating one pouch in 20â¯mL of media (specific to each assay) with the inclusion of the pouch material. NP extracts did not induce any cytotoxicity or mutagenic response, genotoxic response was minimal and limited signalling or inflammatory markers were induced. In contrast, CRP1.1 induced a positive response in four toxicological endpoints in the absence of S9: Srxn1 (oxidative stress), Btg2 (cell stress), Ddit3 (protein damage) and Rtkn (DNA damage), and three endpoints in presence of S9: Srxn1, Ddit3 and Rtkn. CRP1.1 was genotoxic when assessed in MLA and activated signalling pathways involved in proliferation and cellular stress and specifically induced phosphorylation of c-JUN, CREB1, p53, p38 MAPK and to a lesser extent AKT1S1, GSK3α/ß, ERK1/2 and RSK1 in a dose-dependent manner. CRP 1.1 extracts resulted in the release of several inflammatory mediators including cytokines IL-1α, IL5, IL6, IL8, IL-1RA, MIF and TNF-ß, receptor IL-2RA, and growth factors FGF-basic, VEGF and M-CSF. In conclusion these assays contribute to the weight of evidence assessment of the potential comparative health risks of NPs and snus.
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Nicotina , Tabaco sem Fumaça , Camundongos , Animais , Nicotina/análise , Tabaco sem Fumaça/toxicidade , Mutagênicos/análise , Estresse OxidativoRESUMO
BACKGROUND: Timely diagnosis of heart failure (HF) and rapid optimisation of guideline-directed medication therapy (GDMT) improves patients qualities of life, reducing mortality and morbidity. Previous papers describe the role of pharmacists in medication optimisation, but not in the diagnosis of HF. AIM: To describe the development, implementation, and evaluation of pharmacist-led heart failure clinics with respect to time from referral to diagnosis, time from diagnosis to first review with a specialist, and the proportion receiving optimal GDMT 180 days after diagnosis. SETTING: Community outpatient clinics in rural west Wales, United Kingdom. DEVELOPMENT: Two experienced non-medical prescribing pharmacists, one of whom had additional diagnostic qualifications in cardiology, delivered the clinic. IMPLEMENTATION: Patients referred with suspected HF were risk-stratified to urgent (within 14 days of referral) or routine (within 42 days) review, based on natriuretic peptide levels. Patients attended the clinic for assessment, including physical examination, electrocardiogram, and echocardiogram. Those with HF with reduced ejection fraction were initiated on drug treatment and referred to the follow-up pharmacist-led GDMT clinic. EVALUATION: A sample of 100 patients was evaluated (50 from pre-existing and 50 from new service). Median time from referral to diagnosis reduced from 61 days (IQR 47-115) to 16 days (IQR 10.5-27.5) for urgent and 19 days (IQR 11.5-33) for routine. Median time to first appointment following diagnosis reduced from 54 days (IQR 36-60.5) to 14 days (IQR 9.75-28.75) (p value < 0.0001), and proportion of patients achieving GDMT at 180 days following diagnosis improved from 24 to 86% (p value < 0.0001). CONCLUSION: This pharmacist HF diagnostic clinic and medication optimisation clinic improved time to diagnosis, time to first specialist review, and proportion of patients' achieving GDMT optimisation in a rural healthcare setting.
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Birds of prey frequently feature in reintroductions and the hacking technique is typically used. Hacking involves removing large nestlings from donor populations, transferring them to captivity, feeding them ad libitum. Potentially, via the hacking method, the stress of captivity and disruption of parental feeding may be detrimental. Alternatively, the provision of ad libitum food may be advantageous. Although hacking has underpinned reintroduction project successes there has been no research on how the method may affect the health and nutritional status of translocated birds during captivity. We compared blood chemistry data from 55 young White-tailed Eagles, translocated from Norway as part of the species' reintroduction to Scotland, from sampling soon after arriving in captivity and again (≈42 days later) before their release. Numerous significant differences between the first and second samples were found, but no significant interactions showed that the sexes responded similarly to captivity. According to hematological and biochemical metrics, individuals showed several changes during captivity, including in red blood cell parameters, plasma proteins, and white cellular parameters related to the immune system, that indicated improved health status. Captivity with ad libitum food was associated with decreased urea and uric acid values: high values can indicate nutritional stress. Urea values became more normally distributed before release, indicating that ad libitum food had reduced nutritional differences between early nestlings in the season and later ones. Despite plentiful food, both sexes lost body mass before release, suggesting an inherent physiological mechanism to improve flight performance in fledglings. We conclude that hacking improved the health and nutritional status of released eagles which is likely to enable birds to cope with greater costs of exploratory behavior which they may require in reintroduction projects. In this context, we note the absence of survival differences between hacked and wild raptors in previous research.
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Background: The extent of cortical pathology is an important determinant of multiple sclerosis (MS) severity. Cortical demyelination and neurodegeneration are related to inflammation of the overlying leptomeninges, a more inflammatory CSF milieu and with parenchymal microglia and astroglia activation. These are all components of the compartmentalised inflammatory response. Compartmentalised inflammation is a feature of progressive MS, which is not targeted by disease modifying therapies. Complement is differentially expressed in the MS CSF and complement, and complement receptors, are associated with demyelination and neurodegeneration. Methods: To better understand if complement activation in the leptomeninges is associated with underlying cortical demyelination, inflammation, and microglial activation, we performed a neuropathological study of progressive MS (n = 22, 14 females), neuroinflammatory (n = 8), and non-neurological disease controls (n = 10). We then quantified the relative extent of demyelination, connective tissue inflammation, complement, and complement receptor positive microglia/macrophages. Results: Complement was elevated at the leptomeninges, subpial, and within and around vessels of the cortical grey matter. The extent of complement C1q immunoreactivity correlated with connective tissue infiltrates, whilst activation products C4d, Bb, and C3b associated with grey matter demyelination, and C3a receptor 1+ and C5a receptor 1+ microglia/macrophages closely apposed C3b labelled cells. The density of C3a receptor 1+ and C5a receptor 1+ cells was increased at the expanding edge of subpial and leukocortical lesions. C5a receptor 1+ cells expressed TNFα, iNOS and contained puncta immunoreactive for proteolipid protein, neurofilament and synaptophysin, suggesting their involvement in grey matter lesion expansion. Interpretation: The presence of products of complement activation at the brain surfaces, their association with the extent of underlying pathology and increased complement anaphylatoxin receptor positive microglia/macrophages at expanding cortical grey matter lesions, could represent a target to modify compartmentalised inflammation and cortical demyelination.
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We have investigated the heterodimerization of ORL1 receptors and classical members of the opioid receptor family. All three classes of opioid receptors could be co-immunoprecipitated with ORL1 receptors from both transfected tsA-201 cell lysate and rat dorsal root ganglia lysate, suggesting that these receptors can form heterodimers. Consistent with this hypothesis, in cells expressing either one of the opioid receptors together with ORL1, prolonged ORL1 receptor activation via nociceptin application resulted in internalization of the opioid receptors. Conversely, mu-, delta-, and kappa-opioid receptor activation with the appropriate ligands triggered the internalization of ORL1. The mu-opioid receptor/ORL1 receptor heterodimers were shown to associate with N-type calcium channels, with activation of mu-opioid receptors triggering N-type channel internalization, but only in the presence of ORL1. Furthermore, the formation of opioid receptor/ORL1 receptor heterodimers attenuated the ORL1 receptor-mediated inhibition of N-type channels, in part because of constitutive opioid receptor activity. Collectively, our data support the existence of heterodimers between ORL1 and classical opioid receptors, with profound implications for effectors such as N-type calcium channels.
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Canais de Cálcio Tipo N/metabolismo , Receptores Opioides/metabolismo , Animais , Canais de Cálcio Tipo N/genética , Linhagem Celular , Peptídeos Opioides/farmacologia , Estrutura Quaternária de Proteína/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores Opioides/genética , Vasodilatadores/farmacologia , Receptor de Nociceptina , NociceptinaRESUMO
Euphausiids are a keystone species in coastal food webs due to their high lipid content and seasonally high biomass. Understanding the habitat and environmental drivers that lead to areas of high biomass, or 'hotspots', and their seasonal persistence, will support the identification of important foraging regions for mid- and upper- trophic level predators. We quantify the distribution of hotspots of the two dominant species of euphausiid in the north-east Pacific Ocean: Euphausia pacifica and Thysanoessa spinifera, as well as euphausiid larvae (mixed species). The Canadian coast encompasses the northern California Current Ecosystem and the transition zone to the Alaska current, and is a highly productive region for fisheries, marine mammals, and seabirds. We used spatiotemporal modelling to predict the distribution of these three euphausiid groups in relation to geomorphic and environmental variables during the important spring-summer months (April through September) when euphausiid biomass is highest. We quantified the area, intensity, and persistence of biomass hotspots across months according to specific oceanographic ecosections developed for marine spatial planning purposes. Persistent hotspots of both adult species were predicted to occur along the 200 m depth contour of the continental slope; however, differences were predicted on the shallower Dixon shelf, which was a key area for T. spinifera, and within the Juan de Fuca Eddy system where E. pacifica hotspots occurred. The continental slope along the west coast of Vancouver Island was the only persistent hotspot region common between both adult species and euphausiid larvae. Larval distribution was more correlated with T. spinifera than E. pacifica biomass. Hotspots of adults were more persistent across months than hotspots of euphausiid larvae, which were seasonally patchy. The persistence of biomass hotspots of forage species through periods of low overall biomass could maintain trophic connectivity through perturbation events and increase ecosystem resilience to climate change.
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Biomassa , Euphausiacea/crescimento & desenvolvimento , Animais , Canadá , Mudança Climática , EcossistemaRESUMO
The inhibition of N-type calcium channels by opioid receptor like receptor 1 (ORL1) is a key mechanism for controlling the transmission of nociceptive signals. We recently reported that signaling complexes consisting of ORL1 receptors and N-type channels mediate a tonic inhibition of calcium entry. Here we show that prolonged ( approximately 30 min) exposure of ORL1 receptors to their agonist nociceptin triggers an internalization of these signaling complexes into vesicular compartments. This effect is dependent on protein kinase C activation, occurs selectively for N-type channels and cannot be observed with mu-opioid or angiotensin receptors. In expression systems and in rat dorsal root ganglion neurons, the nociceptin-mediated internalization of the channels is accompanied by a significant downregulation of calcium entry, which parallels the selective removal of N-type calcium channels from the plasma membrane. This may provide a new means for long-term regulation of calcium entry in the pain pathway.
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Canais de Cálcio Tipo N/fisiologia , Dor/fisiopatologia , Receptores Opioides/fisiologia , Compostos de Anilina , Animais , Canais de Cálcio Tipo N/genética , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Eletrofisiologia , Corantes Fluorescentes , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiologia , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Microscopia Confocal , Receptores Opioides/agonistas , Receptores Opioides/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Xantenos , Receptor de NociceptinaRESUMO
N-type calcium channels are essential mediators of spinal nociceptive transmission. The core subunit of the N-type channel is encoded by a single gene, and multiple N-type channel isoforms can be generated by alternate splicing. In particular, cell-specific inclusion of an alternatively spliced exon 37a generates a novel form of the N-type channel that is highly enriched in nociceptive neurons and, as we show here, downregulated in a neuropathic pain model. Splice isoform-specific small interfering RNA silencing in vivo reveals that channels containing exon 37a are specifically required for mediating basal thermal nociception and for developing thermal and mechanical hyperalgesia during inflammatory and neuropathic pain. In contrast, both N-type channel isoforms (e37a- and e37b-containing) contribute to tactile neuropathic allodynia. Hence, exon 37a acts as a molecular switch that tailors the channels toward specific roles in pain.
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Processamento Alternativo , Canais de Cálcio Tipo N/fisiologia , Regulação para Baixo/fisiologia , Neuralgia/genética , Análise de Variância , Animais , Animais Recém-Nascidos , Canais de Cálcio Tipo N/classificação , Canais de Cálcio Tipo N/genética , Canais de Cálcio Tipo N/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática/métodos , Gânglios Espinais/citologia , Hiperalgesia/classificação , Hiperalgesia/genética , Hiperalgesia/fisiopatologia , Hiperalgesia/prevenção & controle , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Neuralgia/classificação , Neuralgia/tratamento farmacológico , Neurônios Aferentes/efeitos dos fármacos , Medição da Dor/métodos , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Técnicas de Patch-Clamp/métodos , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Substância P/metabolismoRESUMO
Calcium influx into presynaptic nerve terminals via voltage-gated Ca2+ channels is an essential step in neurotransmitter release. The predominant Ca2+ channel species in synaptic nerve terminals are P/Q-type and N-type channels, with their relative levels of expression varying across the nervous system. The different distributions of these two channel subtypes are reflected in their distinct physiological and pathological roles, yet their activity is regulated by common mechanisms and both function as part of larger signaling complexes that enable their precise regulation and subcellular targeting. Here, we provide a broad overview of molecular and cellular mechanisms that regulate Ca2+ channels, and how these cellular signaling pathways are integrated at the level of the channel protein.
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Potenciais de Ação/fisiologia , Canais de Cálcio/fisiologia , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Neurônios/fisiologia , Terminações Pré-Sinápticas/fisiologia , Transmissão Sináptica/fisiologia , Cálcio/química , Canais de Cálcio/química , Ativação do Canal Iônico/fisiologia , Relação Estrutura-AtividadeRESUMO
The complement pathway has potential contributions to both white (WM) and grey matter (GM) pathology in Multiple Sclerosis (MS). A quantitative assessment of complement involvement is lacking. Here we describe the use of Tissue MicroArray (TMA) methodology in conjunction with immunohistochemistry to investigate the localization of complement pathway proteins in progressive MS cortical GM and subcortical WM. Antibodies targeting complement proteins C1q, C3b, regulatory proteins C1 inhibitor (C1INH, complement receptor 1 (CR1), clusterin, factor H (FH) and the C5a anaphylatoxin receptor (C5aR) were utilised alongside standard markers of tissue pathology. All stained slides were digitised for quantitative analysis. We found that numbers of cells immunolabelled for HLA-DR, GFAP, C5aR, C1q and C3b were increased in WM lesions (WML) and GM lesions (GML) compared to normal appearing WM (NAWM) and GM (NAGM), respectively. The complement regulators C1INH, CR1, FH and clusterin were more abundant in WM lesions, while the number of C1q+ neurons were increased and the number of C1INH+, clusterin+, FH+ and CR1+ neurons decreased in GM lesions. The number of complement component positive cells (C1q, C3b) correlated with complement regulator expression in WM, but there was no statistical association between complement activation and regulator expression in the GM. We conclude that TMA methodology and quantitative analysis provides evidence of complement dysregulation in MS GML, including an association of the numerical density of C1q+ cells with tissue lesions. Our work confirms that complement activation and dysregulation occur in all cases of progressive MS and suggest that complement may provide potential biomarkers of the disease.
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Encéfalo/imunologia , Ativação do Complemento , Esclerose Múltipla/imunologia , Análise Serial de Tecidos/métodos , Adulto , Idoso , Astrócitos/imunologia , Astrócitos/patologia , Encéfalo/patologia , Feminino , Substância Cinzenta/imunologia , Substância Cinzenta/patologia , Humanos , Imuno-Histoquímica , Rim/imunologia , Rim/patologia , Masculino , Microglia/imunologia , Microglia/patologia , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Neurônios/imunologia , Neurônios/patologia , Substância Branca/imunologia , Substância Branca/patologiaRESUMO
1. We have investigated the effects of the endocannabinoid anandamide (AEA) on neuronal excitability and vanilloid TRPV1 receptors in neonatal rat cultured dorsal root ganglion neurones. 2. Using whole-cell patch-clamp electrophysiology, we found that AEA inhibits high-voltage-activated Ca(2+) currents by 33+/-9% (five out of eight neurones) in the absence of the CB(1) receptor antagonist SR141716A (100 nM) and by 32+/-6% (seven out of 10 neurones) in the presence of SR141716A. 3. Fura-2 fluorescence Ca(2+) imaging revealed that AEA produced distinct effects on Ca(2+) transients produced by depolarisation evoked by 30 mM KCl. In a population of neurones of larger somal area (372+/-20 microM(2)), it significantly enhanced Ca(2+) transients (80.26+/-13.12% at 1 microM), an effect that persists after pertussis toxin pretreatment. In a population of neurones of smaller somal area (279+/-18 microM(2)), AEA significantly inhibits Ca(2+) transients (30.75+/-3.54% at 1 microM), an effect that is abolished by PTX pretreatment. 4. Extracellular application of 100 nM AEA failed to evoke TRPV1 receptor inward currents in seven out of eight neurones that responded to capsaicin (1 microM), with a mean inward current of -0.94+/-0.21 nA. In contrast, intracellular application of 100 nM AEA elicited robust inward currents in approximately 62% of neurones, the mean population response was -0.85+/-0.21 nA. When AEA was applied to the intracellular environment with capsazepine (1 microM), the mean population inward current was -0.01+/-0.01 nA. Under control conditions, mean population current fluctuations of -0.09+/-0.05 nA were observed.
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Ácidos Araquidônicos/farmacologia , Capsaicina/análogos & derivados , Gânglios Espinais/citologia , Neurônios Aferentes/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio/fisiologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Capsaicina/farmacologia , Células Cultivadas , Sinergismo Farmacológico , Endocanabinoides , Fura-2/química , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/fisiologia , Toxina Pertussis/farmacologia , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas , Cloreto de Potássio/farmacologia , Pirazóis/farmacologia , Ratos , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptor CB1 de Canabinoide/fisiologia , Receptores de Droga/antagonistas & inibidores , Receptores de Droga/efeitos dos fármacos , Rimonabanto , Canais de Cátion TRPVRESUMO
BACKGROUND: Gabapentin and pregabalin have wide-ranging therapeutic actions, and are structurally related to the inhibitory neurotransmitter GABA. Gabapentin, pregablin and GABA can all modulate voltage-activated Ca2+ channels. In this study we have used whole cell patch clamp recording and fura-2 Ca2+ imaging to characterise the actions of pregabalin on the electrophysiological properties of cultured dorsal root ganglion (DRG) neurones from neonatal rats. The aims of this study were to determine whether pregabalin and gabapentin had additive inhibitory effects on high voltage-activated Ca2+ channels, evaluate whether the actions of pregabalin were dependent on GABA receptors and characterise the actions of pregabalin on voltage-activated potassium currents. RESULTS: Pregabalin (25 nM - 2.5 microM) inhibited 20-30% of the high voltage-activated Ca2+ current in cultured DRG neurones. The residual Ca2+ current recorded in the presence of pregabalin was sensitive to the L-type Ca2+ channel modulator, Bay K8644. Saturating concentrations of gabapentin failed to have additive effects when applied with pregabalin, indicating that these two compounds act on the same type(s) of voltage-activated Ca2+ channels but the majority of Ca2+ current was resistant to both drugs. The continual application of GABA, the GABAB receptor antagonist CGP52432, or intracellular photorelease of GTP-gamma-S had no effect on pregabalin-induced inhibition of Ca2+ currents. Although clear inhibition of Ca2+ influx was produced by pregabalin in a population of small neurones, a significant population of larger neurones showed enhanced Ca2+ influx in response to pregabalin. The enhanced Ca2+ influx evoked by pregabalin was mimicked by partial block of K+ conductances with tetraethylammonium. Pregabalin produced biphasic effects on voltage-activated K+ currents, the inhibitory effect of pregabalin was prevented with apamin. The delayed enhancement of K+ currents was attenuated by pertussis toxin and by intracellular application of a (Rp)-analogue of cAMP. CONCLUSIONS: Pregabalin reduces excitatory properties of cultured DRG neurones by modulating voltage-activated Ca2+ and K+ channels. The pharmacological activity of pregabalin is similar but not identical to that of gabapentin. The actions of pregabalin may involve both extracellular and intracellular drug target sites and modulation of a variety of neuronal conductances, by direct interactions, and through intracellular signalling involving protein kinase A.
Assuntos
Aminas/farmacologia , Ácidos Cicloexanocarboxílicos/farmacologia , Eletrofisiologia/métodos , Gânglios Espinais/fisiologia , Neurônios/efeitos dos fármacos , Ácido gama-Aminobutírico/análogos & derivados , Ácido gama-Aminobutírico/farmacologia , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Células Cultivadas , Corantes Fluorescentes/metabolismo , Fura-2/metabolismo , Proteínas de Ligação ao GTP/fisiologia , Gabapentina , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Neurônios/fisiologia , Técnicas de Patch-Clamp/métodos , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Pregabalina , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/fisiologia , Receptores de GABA/metabolismoRESUMO
BACKGROUND: Prolonged sitting is prevalent in the workplace and is associated with adverse health markers. PURPOSE: Investigate the effects of point-of-choice (PoC) prompting software, on the computer used at work (PC), to reduce long uninterrupted sedentary periods and total sedentary time at work. DESIGN: Assessor-blinded, parallel group, active-controlled randomized trial. SETTING/PARTICIPANTS: A convenience sample of office workers from Glasgow, United Kingdom. Data were collected April to June 2010, and analyzed October 2010 to June 2011. INTERVENTION: The education group (n=14) received a brief education session on the importance of reducing long sitting periods at work. The PoC group (n=14) received the same education along with prompting software on their PC for 5 workdays, which reminded them to stand up every 30 minutes. MAIN OUTCOME MEASURES: Sitting time was measured objectively using the activPAL™ activity monitor for 5 workdays at baseline and 5 workdays during the intervention. The number and time spent sitting in events >30 minutes' duration were the main outcome measures. RESULTS: At baseline, participants spent 5.7±1.0 hours/day (76%±9%) of their time at work sitting. Of that time, 3.3±1.3 hours/day was spent sitting in 3.7±1.4 events >30 minutes. There was a significant difference between the groups in the change (intervention to baseline) of both the number (ANCOVA; -6.8%, p=0.014) and duration (-15.5%, p=0.007) of sitting events >30 minutes. During the intervention, compared with baseline, the PoC group reduced the number (paired t-test; -0.11 events/hour, p=0.045) and duration (-12.2%, p=0.035) of sitting events >30 minutes. However, there was no significant difference in total sitting time between groups (-4.4%, p=0.084). CONCLUSIONS: Point-of-choice prompting software on work computers recommending taking a break from sitting plus education is superior to education alone in reducing long uninterrupted sedentary periods at work. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.govNCT01628861.
Assuntos
Promoção da Saúde/métodos , Comportamento Sedentário , Software , Local de Trabalho , Adulto , Feminino , Comportamentos Relacionados com a Saúde , Educação em Saúde/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Escócia , Método Simples-Cego , Fatores de TempoRESUMO
PURPOSE: Childhood absence epilepsy (CAE) is an idiopathic form of seizure disorder that is believed to have a genetic basis. METHODS: We examined the biophysical consequences of seven mutations in the Ca(v)3.2 T-type calcium channel gene linked to CAE. RESULTS: Of the channel variants examined, one of the mutants, a replacement of glycine 848 in the domain II-S2 region with serine, resulted in significant slowing of the time courses of both activation and inactivation across a wide range of membrane potentials. These changes are consistent with increased channel activity in response to prolonged membrane depolarizations. CONCLUSIONS: Taken together, these findings suggest that such little changes in channel gating may contribute to the etiology of CAE.