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1.
Nature ; 618(7963): 94-101, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37100916

RESUMO

Increasing soil carbon and nitrogen storage can help mitigate climate change and sustain soil fertility1,2. A large number of biodiversity-manipulation experiments collectively suggest that high plant diversity increases soil carbon and nitrogen stocks3,4. It remains debated, however, whether such conclusions hold in natural ecosystems5-12. Here we analyse Canada's National Forest Inventory (NFI) database with the help of structural equation modelling (SEM) to explore the relationship between tree diversity and soil carbon and nitrogen accumulation in natural forests. We find that greater tree diversity is associated with higher soil carbon and nitrogen accumulation, validating inferences from biodiversity-manipulation experiments. Specifically, on a decadal scale, increasing species evenness from its minimum to maximum value increases soil carbon and nitrogen in the organic horizon by 30% and 42%, whereas increasing functional diversity enhances soil carbon and nitrogen in the mineral horizon by 32% and 50%, respectively. Our results highlight that conserving and promoting functionally diverse forests could promote soil carbon and nitrogen storage, enhancing both carbon sink capacity and soil nitrogen fertility.


Assuntos
Biodiversidade , Sequestro de Carbono , Carbono , Florestas , Nitrogênio , Solo , Árvores , Carbono/metabolismo , Nitrogênio/metabolismo , Solo/química , Árvores/classificação , Árvores/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(2): e2212780120, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36595673

RESUMO

Large projected increases in forest disturbance pose a major threat to future wood fiber supply and carbon sequestration in the cold-limited, Canadian boreal forest ecosystem. Given the large sensitivity of tree growth to temperature, warming-induced increases in forest productivity have the potential to reduce these threats, but research efforts to date have yielded contradictory results attributed to limited data availability, methodological biases, and regional variability in forest dynamics. Here, we apply a machine learning algorithm to an unprecedented network of over 1 million tree growth records (1958 to 2018) from 20,089 permanent sample plots distributed across both Canada and the United States, spanning a 16.5 °C climatic gradient. Fitted models were then used to project the near-term (2050 s time period) growth of the six most abundant tree species in the Canadian boreal forest. Our results reveal a large, positive effect of increasing thermal energy on tree growth for most of the target species, leading to 20.5 to 22.7% projected gains in growth with climate change under RCP 4.5 and 8.5. The magnitude of these gains, which peak in the colder and wetter regions of the boreal forest, suggests that warming-induced growth increases should no longer be considered marginal but may in fact significantly offset some of the negative impacts of projected increases in drought and wildfire on wood supply and carbon sequestration and have major implications on ecological forecasts and the global economy.


Assuntos
Taiga , Árvores , Canadá , Ecossistema , Florestas , Mudança Climática
4.
Histochem Cell Biol ; 160(6): 577-593, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37750996

RESUMO

Plasma concentrations of N-arachidonyletholamine (AEA), N-oleoylethanolamide (OEA) and N-palmitoylethanolamide (PEA) increase at term and can predict when a woman is likely to go into labour. We hypothesised that increased plasma AEA concentrations in women in preterm and term labour might also be increased and have a function in the placenta at the end of pregnancy. Here we examined the expression of the N-acylethanolamine-modulating enzymes fatty acid amide hydrolase (FAAH) and N-acyl-phosphatidylethanolamine-specific phospholipase-D (NAPE-PLD) and of the cannabinoid receptors (CB1 and CB2) in the placenta and their activation in an in vitro model of the third-trimester placenta to determine if those expressions change with labour and have functional significance. Expression of CB1, CB2, FAAH and NAPE-PLD was examined by immunohistochemistry (IHC) and RT-qPCR in placental samples obtained from four patient groups: preterm not in labour (PTNL), term not in labour (TNL), preterm in labour (PTL) and term in labour (TL). Additionally, the effects of AEA on a third-trimester human cell line (TCL-1) were evaluated. All ECS components were present in the third-trimester placenta, with NAPE-PLD and CB2 being the key modulated proteins in terms of expression. Functionally, AEA reduced TCL-1 cell numbers through the actions of the CB2 receptor whilst CB1 maintained placental integrity through the expression of the transcription regulators histone deacetylase 3, thyroid hormone receptor ß 1 and the modulation of 5α reductase type 1. The placenta in the third trimester and at term is different from the placenta in the first trimester with respect to the expression of CB1, CB2, FAAH and NAPE-PLD, and the expression of these proteins is affected by labour. These data suggest that early perturbation of some ECS components in the placenta may cause AEA-induced PTL and thus PTB.


Assuntos
Endocanabinoides , Placenta , Recém-Nascido , Humanos , Feminino , Gravidez , Endocanabinoides/metabolismo , Placenta/metabolismo , Receptores de Canabinoides/metabolismo , Primeiro Trimestre da Gravidez/metabolismo
5.
Glob Chang Biol ; 29(18): 5397-5414, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37395653

RESUMO

Reports of forest sensitivity to climate change are based largely on the study of overstory trees, which contribute significantly to forest growth and wood supply. However, juveniles in the understory are also critical to predict future forest dynamics and demographics, but their sensitivity to climate remains less known. In this study, we applied boosted regression tree analysis to compare the sensitivity of understory and overstory trees for the 10 most common tree species in eastern North America using growth information from an unprecedented network of nearly 1.5 million tree records from 20,174 widely distributed, permanent sample plots across Canada and the United States. Fitted models were then used to project the near-term (2041-2070) growth for each canopy and tree species. We observed an overall positive effect of warming on tree growth for both canopies and most species, leading to an average of 7.8%-12.2% projected growth gains with climate change under RCP 4.5 and 8.5. The magnitude of these gains peaked in colder, northern areas for both canopies, while growth declines are projected for overstory trees in warmer, southern regions. Relative to overstory trees, understory tree growth was less positively affected by warming in northern regions, while displaying more positive responses in southern areas, likely driven by the buffering effect of the canopy from warming and climate extremes. Observed differences in climatic sensitivity between canopy positions underscore the importance of accounting for differential growth responses to climate between forest strata in future studies to improve ecological forecasts. Furthermore, latitudinal variation in the differential sensitivity of forest strata to climate reported here may help refine our comprehension of species range shift and changes in suitable habitat under climate change.


Assuntos
Ecossistema , Florestas , Canadá , Mudança Climática
6.
Occup Environ Med ; 80(2): 97-103, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36635100

RESUMO

BACKGROUND: Asbestos has been hypothesised as the cause of the recent global increase in the incidence of 'idiopathic' pulmonary fibrosis (IPF). Establishing this has important diagnostic and therapeutic implications. The association between occupational asbestos exposure and IPF, and interaction with a common (minor allele frequency of 9% in European populations) genetic variant associated with IPF, MUC5B rs35705950, is unknown. METHODS: Multicentre, incident case-control study. Cases (n=494) were men diagnosed with IPF at 21 UK hospitals. Controls (n=466) were age-matched men who attended a hospital clinic in the same period. Asbestos exposure was assessed at interview using a validated job exposure matrix and a source-receptor model. The primary outcome was the association between asbestos exposure and IPF, estimated using logistic regression adjusted for age, smoking and centre. Interaction with MUC5B rs35705950 was investigated using a genetic dominant model. RESULTS: 327 (66%) cases and 293 (63%) controls ever had a high or medium asbestos exposure risk job; 8% of both cases and controls had cumulative exposure estimates ≥25 fibre ml⁻¹ years. Occupational asbestos exposure was not associated with IPF, adjusted OR 1.1 (95% CI 0.8 to 1.4; p=0.6) and there was no gene-environment interaction (p=0.3). Ever smoking was associated with IPF, OR 1.4 (95% CI 1 to 1.9; p=0.04) and interacted with occupational asbestos exposure, OR 1.9 (95% CI 1 to 3.6; p=0.04). In a further non-specified analysis, when stratifying for genotype there was significant interaction between smoking and work in an exposed job (p<0.01) for carriers of the minor allele of MUC5B rs35705950. CONCLUSION: Occupational asbestos exposure alone, or through interaction with MUC5B rs35705950 genotype, was not associated with IPF. Exposure to asbestos and smoking interact to increase IPF risk in carriers of a common genetic variant, the minor allele of MUC5B rs35705950. TRIAL REGISTRATION NUMBER: NCT03211507.


Assuntos
Amianto , Fibrose Pulmonar Idiopática , Exposição Ocupacional , Masculino , Humanos , Feminino , Estudos de Casos e Controles , Fibrose Pulmonar Idiopática/etiologia , Fibrose Pulmonar Idiopática/genética , Genótipo , Exposição Ocupacional/efeitos adversos , Amianto/efeitos adversos
7.
Glob Chang Biol ; 28(2): 542-556, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34606657

RESUMO

Despite great concern for drought-driven forest mortality, the effects of frequent low-intensity droughts have been largely overlooked in the boreal forest because of their negligible impacts over the short term. In this study, we used data from 6876 permanent plots distributed across most of the Canadian boreal zone to assess the effects of repeated low-intensity droughts on forest mortality. Specifically, we compared the relative impact of sequential years under low-intensity dry conditions with the effects of variables related to the intensity of dry conditions, stand characteristics, and local climate. Then, we searched for thresholds in forest mortality as a function of the number of years between two forest surveys affected by dry conditions of any intensity. Our results showed that, in general, frequent low-intensity dry conditions had stronger effects on forest mortality than the intensity of the driest conditions in the plot. Frequent low-intensity dry conditions acted as an inciting factor of forest mortality exacerbated by stand characteristics and environmental conditions. Overall, the mortality of forests dominated by shade-tolerant conifers was significantly and positively related to frequent low-intensity dry conditions, supporting, in some cases, the existence of thresholds delimiting contrasting responses to drought. In mixtures with broadleaf species, however, sequential dry conditions had a negligible impact. The effects of frequent dry conditions on shade-intolerant forests mainly depended on local climate, inciting or mitigating the mortality of forests located in wet places and dominated by broadleaf species or jack pine, respectively. Our results highlight the importance of assessing not only climate-driven extreme events but also repeated disturbances of low intensity. In the long term, the smooth response of forests to dry conditions might abruptly change leading to disproportional mortality triggered by accumulated stress conditions. Forest and wildlife managers should consider the cumulative effects of climate change on mortality to avoid shortfalls in timber and habitat.


Assuntos
Secas , Taiga , Canadá , Mudança Climática , Florestas , Árvores
8.
Histochem Cell Biol ; 156(5): 449-460, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34324032

RESUMO

Although the expression of the putative cannabinoid receptor GPR55 has been shown to be involved in the growth of various tumours and is increased in a number of cancers, its expression has not been examined in patients with endometrial cancer (EC). Quantitative RT-PCR (for mRNA levels) and immunohistochemistry (for protein levels) were used to measure GPR55 expression in patients with Type 1 and Type 2 EC and correlated against cannabinoid receptor (CB1 and CB2) protein levels using non-cancerous endometrium as the control tissue. The data indicated that GPR55 transcript and GPR55 protein levels were significantly (p < 0.002 and p < 0.0001, respectively) higher in EC tissues than in control tissues. The levels of immunoreactive GPR55 protein were correlated with GPR55 transcript levels, but not with the expression of CB1 receptor protein, and were inversely correlated with CB2 protein expression, which was significantly decreased. It can be concluded that GPR55 expression is elevated in women with EC, and thus could provide a potential novel biomarker and therapeutic target for this disease.


Assuntos
Neoplasias do Endométrio/genética , Receptores de Canabinoides/genética , Idoso , Neoplasias do Endométrio/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Receptores de Canabinoides/metabolismo
9.
Nutr Cancer ; 73(7): 1092-1107, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32674720

RESUMO

BACKGROUND AND AIMS: Ovarian cancer is the leading cause of female reproductive cancer death. It is estimated that dietary habits accounts for 30% of all cancers. This review sets out what we know about the food, nutrition and lifestyle factors that cause ovarian cancer, affect women with ovarian cancer and the problems associated with study design that may affect its prevention and patient survival. METHODS: Studies reporting lifestyle, diet, nutritional benefits in ovarian cancer patients from 1980 to date were examined and insights into the potential problems related with study design evaluated. RESULTS: Poor diet and nutrition are associated with ovarian cancer and exacerbated by poor lifestyle choices. Although improvements in disease prevention and patient survival can be made through nutritional, dietary and lifestyle interventions uncertain evidence, resulting directly or indirectly from inadequate study design may negate this. CONCLUSIONS: Lifestyle, dietary and nutrition interventions may prevent and improve survival of ovarian cancer patients. However, inadequate clarity and gaps exists within the literature, eg., study design, data interpretation, absence of cohesive questions and scoring systems. Future directions that emphasize high quality studies and clinical trials should be encouraged.


Assuntos
Estilo de Vida , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Dieta , Feminino , Humanos , Estado Nutricional
10.
Am J Respir Crit Care Med ; 200(10): 1228-1233, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31348686

RESUMO

Rationale: There is an aspiration to retain increasing numbers of older workers in employment, and strategies to achieve this need to make provision for the increasing prevalence of chronic diseases with age. There is a consistent body of cross-sectional evidence that suggests that patients with chronic obstructive pulmonary disease are more likely to have adverse employment outcomes.Objectives: We report the findings of the first longitudinal study of this issue.Methods: We recruited full-time employed men and women in their 50s and followed them for a period of 18 months; we examined, after adjustment for potential confounders, the associations between breathlessness and airway obstruction at baseline and loss of employment in the intervening period.Measurements and Main Results: Among participants responding to the follow-up questionnaire (1,656 of 1,773 [93%]), the majority (78.5%) continued in full-time employment, but 10.6% were in part-time employment and 10.9% were no longer in paid employment. The adjusted risk of loss of employment was significantly increased for those with moderate or severe chronic obstructive pulmonary disease (risk ratio, 2.89; 95% confidence interval, 1.80-4.65) or breathlessness (risk ratio, 3.07; 95% confidence interval, 2.16-4.37) at baseline. There was no evident modification by sex or by manual/nonmanual work.Conclusions: Airway obstruction and breathlessness are independently associated with premature loss from the workforce in older workers; these observations provide strong support to the available cross-sectional evidence and suggest that interventions to help those with chronic obstructive pulmonary disease who wish to remain in work need to be tested.


Assuntos
Dispneia/complicações , Emprego , Doença Pulmonar Obstrutiva Crônica/complicações , Fatores Etários , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
11.
Nicotine Tob Res ; 21(9): 1239-1247, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-30202883

RESUMO

INTRODUCTION: The aerosol composition of electronic cigarettes (ECs) suggests that exposure to toxicants during use is greatly reduced compared to exposure from combustible cigarettes (CCs). METHODS: This randomized, parallel-group, clinical study enrolled smokers to switch to Vuse Solo (VS) Digital Vapor Cigarettes (Original or Menthol) or Nicorette 4 mg nicotine gum (NG) in a controlled setting. Subjects who smoked CCs ad libitum for 2 days during a baseline period were then randomized to ad libitum use of either VS or NG for 5 days. Biomarkers of 23 toxicants were measured in 24-hour urine samples and blood collected at baseline and following product switch. RESULTS: A total of 153 subjects completed the study. Total nicotine equivalents decreased in all groups, but higher levels were observed in the VS groups compared to the NG groups, with decreases of 38% and 60%-67%, respectively. All other biomarkers were significantly decreased in subjects switched to VS, and the magnitude of biomarker decreases was similar to subjects switched to NG. Decreases ranged from 30% to greater than 85% for constituents such as benzene and acrylonitrile. CONCLUSIONS: These results indicate that exposure to toxicants when using VS is significantly reduced compared to CC smoking, and these reductions are similar to those observed with use of NG. Although statistically significantly decreased, nicotine exposure is maintained closer to CC smoking with VS use compared to NG use. This research suggests that use of VS exposes consumers to fewer and lower levels of smoke toxicants than CCs while still providing nicotine to the consumer. IMPLICATIONS: This is the first study to report changes in nicotine delivery and biomarkers of tobacco exposure following a short-term product switch from CCs to either an EC or NG in a controlled environment. The study shows that nicotine exposure decreased in both groups but was maintained closer to CC smoking with the EC groups. Biomarkers of tobacco combustion decreased to similar levels in both EC and gum groups.


Assuntos
Fumar Cigarros/sangue , Fumar Cigarros/urina , Sistemas Eletrônicos de Liberação de Nicotina , Goma de Mascar de Nicotina/análise , Vaping/sangue , Vaping/urina , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Feminino , Substâncias Perigosas/sangue , Substâncias Perigosas/urina , Humanos , Masculino , Pessoa de Meia-Idade , Nicotina/sangue , Nicotina/urina , Fumantes , Abandono do Hábito de Fumar/métodos
12.
Dermatology ; 235(4): 327-333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31256169

RESUMO

BACKGROUND: The impact of lesion focality and centricity in relation to patient outcome and disease recurrence of vulvar intraepithelial neoplasia (VIN) is an understudied area of research, especially in immunocompromised women. The prevalence and incidence of VIN have increased steadily since the 1980s because of the co-existence of human papillomavirus (HPV) and human immunodeficiency virus (HIV). In this study, we retrospectively examined the records of VIN patients to determine the effect of lesion focality and centricity with respect to the interval to disease recurrence. MATERIALS AND METHODS: All women diagnosed with VIN and managed between January 2002 and December 2011 were included (n = 90) and followed up until December 2017. Symptoms at the time of presentation, including HIV positivity (n = 75), were collated, including the influences of multifocality and multicentricity on time to disease recurrence. RESULTS: Multicentricity caused a more rapid recurrence of disease than unicentricity (p = 0.006), whereas multifocality increased the risk of recurrence more than unifocality (p < 0.0001). Viral load in the HIV+ patients was not associated with time to disease recurrence, but the reduced number of CD4+ lymphocytes present in HIV+ patients was. Treatment modalities had no effect on disease recurrence. CONCLUSION: Both focality and centricity have effects on interval to recurrence and final patient outcome, with multifocal disease having a poorer prognosis. Centricity and focality should be recorded at the time of diagnosis and act as a warning for disease recurrence. HIV+ VIN patients with multifocal disease and/or known immunosuppression (low CD4+ lymphocyte counts) should be regarded as "high-risk" patients and treated accordingly.


Assuntos
Carcinoma in Situ/patologia , Infecções por HIV/imunologia , Neoplasias Vulvares/patologia , Carcinoma in Situ/imunologia , Progressão da Doença , Feminino , Humanos , Hospedeiro Imunocomprometido , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Neoplasias Vulvares/imunologia
13.
J Obstet Gynaecol ; 39(8): 1117-1122, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31195902

RESUMO

There is conflicting literature on whether the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena®) induces decidualisation in the tamoxifen-treated endometrium. The expression of the decidualisation marker IGFBP-1 was measured using immunohistochemistry in endometrial biopsies and in serum (using ELISA) of 20 postmenopausal women at the start of tamoxifen-treatment for breast cancer. Ten women were then fitted with LNG-IUS and the other ten received tamoxifen-treatment only and acted as controls. Samples were taken at baseline and after 12 months. At baseline, all endometrial samples were negative for IGFBP-1 and at 12 months, IGFBP-1 was only expressed in the endometria of women fitted with the LNG-IUS, confirming the observed histological features of decidualisation. By contrast, serum IGFBP-1 concentrations were increased by tamoxifen, but not in the group receiving LNG-IUS. In conclusion, tamoxifen induces a rise in serum IGFBP-1 suggesting a systemic, possibly hepatic effect, whilst LNG abrogates this in both the liver and endometrium. Impact statement What is already known on this subject? Previous reports of the use of LNG-IUS in women on tamoxifen have provided conflicting evidence as to whether the endometrium exhibited decidualisation or not. These reports were however based solely on histological examination and lacked supporting biochemical data. What do the results of this study add? After 12 months of treatment with LNG-IUS, the endometria of women on tamoxifen show histological features of decidualisation and the presence of the decidualisation marker IGFBP-1, suggesting that levonorgestrel protects the tamoxifen-treated uterus from additional pathology by causing decidualisation. Serum levels of IGFBP-1 were expected to be a reflection of uterine production, but contrary to expectations, higher levels were identified in women on tamoxifen alone. These data suggest that an inhibition of tamoxifen-induced serum IGFBP-1 production (possibly from a hepatic source) by LNG-IUS occurred and indicates independent systemic effects of both drugs in post menopausal breast cancer patients. What are the implications of these findings for clinical practice and/or further research? This research demonstrated a mechanism for endometrial protection in women on tamoxifen. It also alerts clinicians to the fact that both tamoxifen and LNG-IUS exert systemic effects in this patient group.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Decídua/efeitos dos fármacos , Endométrio/efeitos dos fármacos , Dispositivos Intrauterinos Medicados , Levanogestrel/administração & dosagem , Tamoxifeno/uso terapêutico , Idoso , Biomarcadores/análise , Decídua/química , Decídua/fisiologia , Endométrio/patologia , Endométrio/fisiologia , Feminino , Humanos , Imuno-Histoquímica , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/análise , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Pessoa de Meia-Idade , Pós-Menopausa
14.
J Recept Signal Transduct Res ; 38(5-6): 385-392, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30569804

RESUMO

The lack of good diagnostic/prognostic biomarkers and the often late presentation of endometrial cancer (EC) hinders the amelioration of the morbidity and mortality rates associated with this primarily estrogen-driven disease, a disease that is becoming more prevalent in the population. Previous studies on the expression of the classical cannabinoid receptors, CB1 and CB2, suggest these could provide good diagnostic/prognostic biomarkers for EC but those observations have been contradictory. In this study, we sought to resolve the inconsistency of CB1 and CB2 expression levels in different EC studies. To that end, we used qRT-PCR and immunohistochemistry (IHC) for CB1 and CB2 in endometrial biopsies from women with or without EC and found that transcript levels for both CB1 and CB2 were significantly decreased by 90 and 80%, respectively in EC. These observations were supported by histomorphometric studies where CB1 and CB2 staining intensity was decreased in all types of EC. These data suggest that the loss of both types of CB receptors is potentially involved in the development of or progression of EC and that CB1 and CB2 receptor expression could serve as useful histological markers and therapeutic targets in the treatment of or prevention of EC.


Assuntos
Neoplasias do Endométrio/genética , Neoplasias Hormônio-Dependentes/genética , Receptor CB1 de Canabinoide/genética , Receptor CB2 de Canabinoide/genética , Neoplasias do Endométrio/patologia , Estrogênios/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Neoplasias Hormônio-Dependentes/patologia
15.
Lancet ; 385 Suppl 1: S20, 2015 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26312842

RESUMO

BACKGROUND: We have previously shown that patients with endometrial carcinoma express elevated concentrations of the endocannabinoid, anandamide (AEA), in both their plasma and their endometrial tissue and that the endometrial carcinoma cell line, Ishikawa, contains the receptors to which AEA binds. Several studies have reported that human and rodent cancer cell lines die in response to high AEA concentrations. The incidence of endometrial carcinoma continues to escalate and, although surgical treatment has improved, morbidity and mortality rates have not. A move towards a novel non-surgical therapeutic option is thus required, and the endocannabinoid system provides a good candidate target. We aimed to investigate the effects of AEA on the survival and proliferation of an endometrial carcinoma cell model. METHODS: This prospective basic research study was conducted at a UK teaching hospital. Ishikawa cells were cultured in vitro, and a range of AEA concentrations (0-10 000 nM) were added to the cells. The effect of AEA was measured at different timepoints (4, 18, 24, 48, and 72 h). Primary outcome was cell proliferation and cell viability as measured with a commercial proliferation-apoptosis assay in which assay colour at 420 nm is directly proportional to cell density. One-way ANOVA was performed with Prism (version 7). FINDINGS: Ishikawa cells were sensitive to AEA-mediated cytotoxicity in a pseudo dose-dependent manner. AEA caused a significant decrease in cell number only at concentrations above 1000 nM (mean 28·1% [SE 7·8], n=12; p<0·0001). The decrease in cell viability that occurred at 4, 18, and 24 h was partly restored at 48 and 72 h suggesting that the AEA growth inhibitory effect is time limiting. INTERPRETATION: Our results show that AEA induces a decrease in Ishikawa cell number probably through inhibition of cell proliferation rather than cell death. These data suggest that the increased plasma and tissue AEA concentrations observed in patients with endometrial cancer is a counter mechanism against further cancer growth and points to the endocannabinoid system as a potentially new therapeutic target. FUNDING: University Hospitals of Leicester NHS Trust.

16.
Mol Hum Reprod ; 21(9): 723-35, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26124453

RESUMO

Real-time quantitative RT-PCR (qRT-PCR) is a powerful technique used for the relative quantification of target genes, using reference (housekeeping) genes for normalization to ensure the generation of accurate and robust data. A systematic examination of the suitability of endogenous reference genes for gene expression studies in endometrial cancer tissues is absent. The aims of this study were therefore to identify and evaluate from the thirty-two possible reference genes from a TaqMan(®) array panel their suitability as an internal control gene. The mathematical software packages geNorm qBasePLUS identified Pumilio homolog 1 (Drosophila) (PUM1), ubiquitin C (UBC), phosphoglycerate kinase (PGK1), mitochondrial ribosomal protein L19 (MRPL19) and peptidylpropyl isomerase A (cyclophilin A) (PPIA) as the best reference gene combination, whilst NormFinder identified MRPL19 as the best single reference gene, with importin 8 (IPO8) and PPIA being the best combination of two reference genes. BestKeeper ranked MRPL19 as the most stably expressed gene. In addition, the study was validated by examining the relative expression of a test gene, which encodes the cannabinoid receptor 1 (CB1). A significant difference in CB1 mRNA expression between malignant and normal endometrium using MRPL19, PPIA, and IP08 in combination was observed. The use of MRPL19, IPO8 and PPIA was identified as the best reference gene combination for the normalization of gene expression levels in endometrial carcinoma. This study demonstrates that the arbitrary selection of endogenous control reference genes for normalization in qRT-PCR studies of endometrial carcinoma, without validation, risks the production of inaccurate data and should therefore be discouraged.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Endometrioide/genética , Neoplasias do Endométrio/genética , Perfilação da Expressão Gênica/normas , Reação em Cadeia da Polimerase em Tempo Real/normas , Algoritmos , Carcinoma Endometrioide/patologia , Estudos de Casos e Controles , Ciclofilina A/genética , Neoplasias do Endométrio/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Mitocondriais/genética , Gradação de Tumores , Valor Preditivo dos Testes , Receptor CB1 de Canabinoide/genética , Valores de Referência , Reprodutibilidade dos Testes , Proteínas Ribossômicas/genética , Software , beta Carioferinas/genética
17.
J Anat ; 227(2): 157-66, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26047022

RESUMO

Mammals may exhibit different forms of locomotion even within a species. A particular form of locomotion (e.g. walk, run, bound) appears to be selected by supraspinal commands, but the precise pattern, i.e. phasing of limbs and muscles, is generated within the spinal cord by so-called central pattern generators. Peripheral sense organs, particularly the muscle spindle, play a crucial role in modulating the central pattern generator output. In turn, the feedback from muscle spindles is itself modulated by static and dynamic fusimotor (gamma) neurons. The activity of muscle spindle afferents and fusimotor neurons during locomotion in the cat is reviewed here. There is evidence for some alpha-gamma co-activation during locomotion involving static gamma motoneurons. However, both static and dynamic gamma motoneurons show patterns of modulation that are distinct from alpha motoneuron activity. It has been proposed that static gamma activity may drive muscle spindle secondary endings to signal the intended movement to the central nervous system. Dynamic gamma motoneuron drive appears to prime muscle spindle primary endings to signal transitions in phase of the locomotor cycle. These findings come largely from reduced animal preparations (decerebrate) and require confirmation in freely moving intact animals.


Assuntos
Gatos/fisiologia , Locomoção/fisiologia , Neurônios Motores gama/fisiologia , Fusos Musculares/fisiologia , Animais , Sistema Nervoso Central/fisiologia , Estado de Descerebração , Eletromiografia , Retroalimentação Sensorial/fisiologia , Fusos Musculares/inervação , Medula Espinal/fisiologia
18.
Nanotechnology ; 26(50): 505301, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26579701

RESUMO

We report low-cost conductometric gas sensors that use an ultrathin film made of graphene oxide (GO) nanoflakes as transducing element. The devices were fabricated by lift-off metallization and near-room temperature, atmospheric pressure electrospray printing using a shadow mask. The sensors are sensitive to reactive gases at room temperature without requiring any post heat treatment, harsh chemical reduction, or doping with metal nanoparticles. The sensors' response to humidity at atmospheric pressure tracks that of a commercial sensor, and is linear with changes in humidity in the 10%-60% relative humidity range while consuming <6 µW. Devices with GO layers printed by different deposition recipes yielded nearly identical response characteristics, suggesting that intrinsic properties of the film control the sensing mechanism. The gas sensors successfully detected ammonia at concentrations down to 500 ppm (absolute partial pressure of ∼5 × 10(-4) T) at ∼1 T pressure, room temperature conditions. The sensor technology can be used in a great variety of applications including air conditioning and sensing of reactive gas species in vacuum lines and abatement systems.

19.
Pflugers Arch ; 466(7): 1421-35, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24114173

RESUMO

The endogenous lipid agent N-arachidonoylethanolamine (anandamide), among other effects, has been shown to be involved in nociceptive processing both in the central and peripheral nervous systems. Anandamide is thought to be synthesised by several enzymatic pathways both in a Ca(2+)-sensitive and Ca(2+)-insensitive manner, and rat primary sensory neurons produce anandamide. Here, we show for the first time, that cultured rat primary sensory neurons express at least four of the five known Ca(2+)-insensitive enzymes implicated in the synthesis of anandamide, and that application of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-arachidonoyl, the common substrate of the anandamide-synthesising pathways, results in anandamide production which is not changed by the removal of extracellular Ca(2+). We also show that anandamide, which has been synthesised in primary sensory neurons following the application of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-arachidonoyl induces a transient receptor potential vanilloid type 1 ion channel-mediated excitatory effect that is not inhibited by concomitant activation of the cannabinoid type 1 receptor. Finally, we show that sub-populations of transient receptor potential vanilloid type 1 ion channel-expressing primary sensory neurons also express some of the putative Ca(2+)-insensitive anandamide-synthesising enzymes. Together, these findings indicate that anandamide synthesised by primary sensory neuron via a Ca(2+)-insensitive manner has an excitatory rather than an inhibitory role in primary sensory neurons and that excitation is mediated predominantly through autocrine signalling. Regulation of the activity of the Ca(2+)-insensitive anandamide-synthesising enzymes in these neurons may be capable of regulating the activity of these cells, with potential relevance to controlling nociceptive processing.


Assuntos
Potenciais de Ação , Ácidos Araquidônicos/metabolismo , Cálcio/metabolismo , Endocanabinoides/metabolismo , Fosfatidiletanolaminas/farmacologia , Alcamidas Poli-Insaturadas/metabolismo , Células Receptoras Sensoriais/metabolismo , Animais , Ácidos Araquidônicos/biossíntese , Células Cultivadas , Endocanabinoides/biossíntese , Gânglios Espinais/citologia , Gânglios Espinais/enzimologia , Gânglios Espinais/metabolismo , Fosfolipases A2 do Grupo IB/genética , Fosfolipases A2 do Grupo IB/metabolismo , Lisofosfolipase/genética , Lisofosfolipase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfatidiletanolaminas/química , Diester Fosfórico Hidrolases/genética , Diester Fosfórico Hidrolases/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Proteína Tirosina Fosfatase não Receptora Tipo 22/metabolismo , Ratos , Ratos Sprague-Dawley , Células Receptoras Sensoriais/enzimologia , Células Receptoras Sensoriais/fisiologia , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo
20.
AAPS PharmSciTech ; 15(3): 542-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24526655

RESUMO

Understanding the product and process variable on the final product performance is an essential part of the quality-by-design (QbD) principles in pharmaceutical development. The hard capsule is an established pharmaceutical dosage form used worldwide in development and manufacturing. The empty hard capsules are supplied as an excipient that is filled by pharmaceutical manufacturers with a variety of different formulations and products. To understand the potential variations of the empty hard capsules as an input parameter and its potential impact on the finished product quality, a study was performed investigating the critical quality parameters within and in between different batches of empty hard gelatin capsules. The variability of the hard capsules showed high consistency within the specification of the critical quality parameters. This also accounts for the disintegration times, when automatic endpoint detection was used. Based on these data, hard capsules can be considered as a suitable excipient for product development using QbD principles.


Assuntos
Excipientes/química , Gelatina/química , Tecnologia Farmacêutica/métodos , Bactérias/isolamento & purificação , Cápsulas , Química Farmacêutica , Corantes/análise , Contaminação de Medicamentos , Excipientes/normas , Gelatina/normas , Dureza , Cinética , Controle de Qualidade , Solubilidade , Dióxido de Enxofre/análise , Tecnologia Farmacêutica/normas
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