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1.
Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration
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Paola Riolo Nunzio Isidoro Sara Ruschioni Roxana L. Minuz Ferdinando Bin Roberto Romani 《Journal of morphology》2016,277(1):128-137
Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here “Antennal Dorsal Organs.” Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla‐like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla‐like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed. J. Morphol. 277:128–137, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
2.
Mayrel Palestino-Domínguez Alejandro Escobedo-Calvario Soraya Salas-Silva Moises Vergara-Mendoza Veronica Souza-Arroyo Roberto Lazzarini Roxana Miranda-Labra Leticia Bucio-Ortiz María Concepción Gutiérrez-Ruiz Luis E. Gomez-Quiroz 《Journal of biochemical and molecular toxicology》2023,37(4):e23302
Alcohol-induced pancreas damage remains as one of the main risk factors for pancreatitis development. This disorder is poorly understood, particularly the effect of acetaldehyde, the primary alcohol metabolite, in the endocrine pancreas. Hepatocyte growth factor (HGF) is a protective protein in many tissues, displaying antioxidant, antiapoptotic, and proliferative responses. In the present work, we were focused on characterizing the response induced by HGF and its protective mechanism in the RINm5F pancreatic cell line treated with ethanol and acetaldehyde. RINm5F cells were treated with ethanol or acetaldehyde for 12 h in the presence or not of HGF (50 ng/ml). Cells under HGF treatment decreased the content of reactive oxygen species and lipid peroxidation induced by both toxics, improving cell viability. This effect was correlated to an improvement in insulin expression impaired by ethanol and acetaldehyde. Using a specific inhibitor of Erk1/2 abrogated the effects elicited by the growth factor. In conclusion, the work provides mechanistic evidence of the HGF-induced-protective response to the alcohol-induced damage in the main cellular component of the endocrine pancreas. 相似文献
3.
4.
Nabil-Fareed Alikhan Luisa Zanolli Moreno Luis Ricardo Castellanos Marie Anne Chattaway Jim McLauchlin Martin Lodge Justin OGrady Roxana Zamudio Emma Doughty Liljana Petrovska Marcos Paulo Vieira Cunha Terezinha Knbl Andrea Micke Moreno Alison E. Mather 《PLoS genetics》2022,18(6)
Non-typhoidal Salmonella enterica is a common cause of diarrhoeal disease; in humans, consumption of contaminated poultry meat is believed to be a major source. Brazil is the world’s largest exporter of chicken meat globally, and previous studies have indicated the introduction of Salmonella serovars through imported food products from Brazil. Here we provide an in-depth genomic characterisation and evolutionary analysis to investigate the most prevalent serovars and antimicrobial resistance (AMR) in Brazilian chickens and assess the impact to public health of products contaminated with S. enterica imported into the United Kingdom from Brazil. To do so, we examine 183 Salmonella genomes from chickens in Brazil and 357 genomes from humans, domestic poultry and imported Brazilian poultry products isolated in the United Kingdom. S. enterica serovars Heidelberg and Minnesota were the most prevalent serovars in Brazil and in meat products imported from Brazil into the UK. We extended our analysis to include 1,259 publicly available Salmonella Heidelberg and Salmonella Minnesota genomes for context. The Brazil genomes form clades distinct from global isolates, with temporal analysis suggesting emergence of these Salmonella Heidelberg and Salmonella Minnesota clades in the early 2000s, around the time of the 2003 introduction of the Enteritidis vaccine in Brazilian poultry. Analysis showed genomes within the Salmonella Heidelberg and Salmonella Minnesota clades shared resistance to sulphonamides, tetracyclines and beta-lactams conferred by sul2, tetA and blaCMY-2 genes, not widely observed in other co-circulating serovars despite similar selection pressures. The sul2 and tetA genes were concomitantly carried on IncC plasmids, whereas blaCMY-2 was either co-located with the sul2 and tetA genes on IncC plasmids or independently on IncI1 plasmids. Long-term surveillance data collected in the UK showed no increase in the incidence of Salmonella Heidelberg or Salmonella Minnesota in human cases of clinical disease in the UK following the increase of these two serovars in Brazilian poultry. In addition, almost all of the small number of UK-derived genomes which cluster with the Brazilian poultry-derived sequences could either be attributed to human cases with a recent history of foreign travel or were from imported Brazilian food products. These findings indicate that even should Salmonella from imported Brazilian poultry products reach UK consumers, they are very unlikely to be causing disease. No evidence of the Brazilian strains of Salmonella Heidelberg or Salmonella Minnesota were observed in UK domestic chickens. These findings suggest that introduction of the Salmonella Enteritidis vaccine, in addition to increasing antimicrobial use, could have resulted in replacement of salmonellae in Brazilian poultry flocks with serovars that are more drug resistant, but less associated with disease in humans in the UK. The plasmids conferring resistance to beta-lactams, sulphonamides and tetracyclines likely conferred a competitive advantage to the Salmonella Minnesota and Salmonella Heidelberg serovars in this setting of high antimicrobial use, but the apparent lack of transfer to other serovars present in the same setting suggests barriers to horizontal gene transfer that could be exploited in intervention strategies to reduce AMR. The insights obtained reinforce the importance of One Health genomic surveillance. 相似文献
5.
Lineage-specific evolution and gene flow in Listeria monocytogenes are independent of bacteriophages
Roxana Zamudio Richard D. Haigh Joseph D. Ralph Megan De Ste Croix Taurai Tasara Katrin Zurfluh Min Jung Kwun Andrew D. Millard Stephen D. Bentley Nicholas J. Croucher Roger Stephan Marco R. Oggioni 《Environmental microbiology》2020,22(12):5058-5072
Listeria monocytogenes is a foodborne pathogen causing systemic infection with high mortality. To allow efficient tracking of outbreaks a clear definition of the genomic signature of a cluster of related isolates is required, but lineage-specific characteristics call for a more detailed understanding of evolution. In our work, we used core genome MLST (cgMLST) to identify new outbreaks combined to core genome SNP analysis to characterize the population structure and gene flow between lineages. Whilst analysing differences between the four lineages of L. monocytogenes we have detected differences in the recombination rate, and interestingly also divergence in the SNP differences between sub-lineages. In addition, the exchange of core genome variation between the lineages exhibited a distinct pattern, with lineage III being the best donor for horizontal gene transfer. Whilst attempting to link bacteriophage-mediated transduction to observed gene transfer, we found an inverse correlation between phage presence in a lineage and the extent of recombination. Irrespective of the profound differences in recombination rates observed between sub-lineages and lineages, we found that the previously proposed cut-off of 10 allelic differences in cgMLST can be still considered valid for the definition of a foodborne outbreak cluster of L. monocytogenes. 相似文献
6.
Lescano AR Blazes DL Montano SM Moran Z Naquira C Ramirez E Lie R Martin GJ Lescano AG Zunt JR 《PloS one》2008,3(9):e3274
With the rapidly increasing number of health care professionals seeking international research experience, comes an urgent need for enhanced capacity of host country institutional review boards (IRB) to review research proposals and ensure research activities are both ethical and relevant to the host country customs and needs. A successful combination of distance learning, interactive courses and expert course instructors has been applied in Peru since 2004 through collaborations between the U.S. Naval Medical Research Center Detachment, the University of Washington and the Department of Clinical Bioethics of the National Institutes of Health to provide training in ethical conduct of research to IRB members and researchers from Peru and other Latin American countries. All training activities were conducted under the auspices of the Peruvian National Institute of Health (INS), Ministry of Health. To date, 927 people from 12 different Latin American countries have participated in several of these training activities. In this article we describe our training model. 相似文献
7.
Raili Koivuniemi Johanna M?kel? Marie-Estelle Hokkanen Céline Bruelle Tho Huu Ho Roxana Ola Laura Korhonen Jim Schr?der Hiroaki Kataoka Dan Lindholm 《PloS one》2013,8(2)
Background
Neural progenitor cells (NPCs) in the developing neuroepithelium are regulated by intrinsic and extrinsic factors. There is evidence that NPCs form a self-supporting niche for cell maintenance and proliferation. However, molecular interactions and cell-cell contacts and the microenvironment within the neuroepithelium are largely unknown. We hypothesized that cellular proteases especially those associated with the cell surface of NPCs play a role in regulation of progenitor cells in the brain.Methodology/Principal Findings
In this work, we show that NPCs, isolated from striatal anlage of developing rat brain, express hepatocyte growth factor activator inhibitor-1 and -2 (HAI-1 and HAI-2) that are cell surface-linked serine protease inhibitors. In addition, radial glia cells derived from mouse embryonic stem cells also express HAI-1 and HAI-2. To study the functional significance of HAI-1 and HAI-2 in progenitor cells, we modulated their levels using expression plasmids or silencing RNA (siRNA) transfected into the NPCs. Data showed that overexpression of HAI-1 or HAI-2 decreased cell proliferation of cultured NPCs, whilst their siRNAs had opposite effects. HAI-1 also influenced NPC differentiation by increasing the number of glial fibrillary acidic protein (GFAP) expressing cells in the culture. Expression of HAI-1 in vivo decreased cell proliferation in developing neuroepithelium in E15 old animals and promoted astrocyte cell differentiation in neonatal animals. Studying the regulation of HAI-1, we observed that Bone morphogenetic protein-2 (BMP-2) and BMP-4 increased HAI-1 levels in the NPCs. Experiments using HAI-1-siRNA showed that these BMPs act on the NPCs partly in a HAI-1-dependent manner.Conclusions
This study shows that the cell-surface serine protease inhibitors, HAI-1 and HAI-2 influence proliferation and cell fate of NPCs and their expression levels are linked to BMP signaling. Modulation of the levels and actions of HAI-1 in NPCs may be of a potential value in stem cell therapies in various brain diseases. 相似文献8.
Elena Larrieta-Carrasco Paola León-Mimila Teresa Villarreal-Molina Hugo Villamil-Ramírez Sandra Romero-Hidalgo Leonor Jacobo-Albavera Roxana Gutiérrez-Vidal Blanca E. López-Contreras Luz E. Guillén-Pineda Fausto Sánchez-Muñoz Rafael Bojalil Ana M. Mejía-Domínguez Nahúm Méndez-Sánchez Aaron Domínguez-López Carlos A. Aguilar-Salinas Samuel Canizales-Quinteros 《Gene》2013
Background and aims
Non-alcoholic fatty liver disease (NAFLD) and elevated alanine transaminase (ALT) levels are common in obese Hispanic adults and children. Recently, a PNPLA3 gene variant (I148M) was strongly associated with NAFLD and higher ALT levels in obese adults, including Hispanics. The aims of this study were to estimate the frequency of elevated ALT levels, and to address the influence of obesity and PNPLA3/I148M on ALT levels in a general population sample of Mexican school-aged children.Methods
A total of 1037 non-related Mexican children aged 6 to 12 years were genotyped for the I148M variant. Anthropometric, clinical and metabolic parameters were collected from all participants.Results
Elevated ALT levels (> 35 U/L) were more frequent in obese (26.9%) and overweight (9.3%) than in normal weight children (2.2%). The M148M genotype was significantly associated with elevated ALT levels in this population (OR = 3.7, 95% CI 2.3–5.9; P = 3.7 × 10− 8), and children carrying the M148M genotype showed significantly lower HDL cholesterol levels and BMI z-core (P = 0.036 and 0.015, respectively). On stratifying by BMI percentile, this genotype conferred a much greater risk of elevated ALT levels in normal weight (OR = 19.9, 95% CI 2.5–157.7; P = 0.005) than overweight and obese children (OR = 3.4, 95% CI 1.3–8.9; P = 0.014 and OR = 3.1, 95% CI 1.7–5.5; P = 1.4 x10− 4, respectively).Conclusions
The I148M PNPLA3 variant is strongly associated with elevated ALT levels in normal weight and overweight/obese Mexican children. Thus, the M148M genotype may be considered as an important risk factor for liver damage in this population. 相似文献9.
Roxana A. Stefanescu R. G. Shivakeshavan Pramod P. Khargonekar Sachin S. Talathi 《Bulletin of mathematical biology》2013,75(11):2208-2240
Channelrhodopsins-2 (ChR2) are a class of light sensitive proteins that offer the ability to use light stimulation to regulate neural activity with millisecond precision. In order to address the limitations in the efficacy of the wild-type ChR2 (ChRwt) to achieve this objective, new variants of ChR2 that exhibit fast mon-exponential photocurrent decay characteristics have been recently developed and validated. In this paper, we investigate whether the framework of transition rate model with 4 states, primarily developed to mimic the biexponential photocurrent decay kinetics of ChRwt, as opposed to the low complexity 3 state model, is warranted to mimic the mono-exponential photocurrent decay kinetics of the newly developed fast ChR2 variants: ChETA (Gunaydin et al., Nature Neurosci. 13:387–392, 2010) and ChRET/TC (Berndt et al., Proc. Natl. Acad. Sci. 108:7595–7600, 2011). We begin by estimating the parameters of the 3-state and 4-state models from experimental data on the photocurrent kinetics of ChRwt, ChETA, and ChRET/TC. We then incorporate these models into a fast-spiking interneuron model (Wang and Buzsaki, J. Neurosci. 16:6402–6413, 1996) and a hippocampal pyramidal cell model (Golomb et al., J. Neurophysiol. 96:1912–1926, 2006) and investigate the extent to which the experimentally observed neural response to various optostimulation protocols can be captured by these models. We demonstrate that for all ChR2 variants investigated, the 4 state model implementation is better able to capture neural response consistent with experiments across wide range of optostimulation protocol. We conclude by analytically investigating the conditions under which the characteristic specific to the 3-state model, namely the monoexponential photocurrent decay of the newly developed variants of ChR2, can occur in the framework of the 4-state model. 相似文献
10.
Mutations in leucine-rich repeat kinase 2 (LRRK2) underlie an autosomal-dominant form of Parkinson''s disease (PD) that is clinically indistinguishable from idiopathic PD. The function of LRRK2 is not well understood, but it has become widely accepted that LRRK2 levels or its kinase activity, which is increased by the most commonly observed mutation (G2019S), regulate neurite growth. However, growth has not been measured; it is not known whether mean differences in length correspond to altered rates of growth or retraction, whether axons or dendrites are impacted differentially or whether effects observed are transient or sustained. To address these questions, we compared several developmental milestones in neurons cultured from mice expressing bacterial artificial chromosome transgenes encoding mouse wildtype-LRRK2 or mutant LRRK2-G2019S, Lrrk2 knockout mice and non-transgenic mice. Over the course of three weeks of development on laminin, the data show a sustained, negative effect of LRRK2-G2019S on dendritic growth and arborization, but counter to expectation, dendrites from Lrrk2 knockout mice do not elaborate more rapidly. In contrast, young neurons cultured on a slower growth substrate, poly-L-lysine, show significantly reduced axonal and dendritic motility in Lrrk2 transgenic neurons and significantly increased motility in Lrrk2 knockout neurons with no significant changes in length. Our findings support that LRRK2 can regulate patterns of axonal and dendritic growth, but they also show that effects vary depending on growth substrate and stage of development. Such predictable changes in motility can be exploited in LRRK2 bioassays and guide exploration of LRRK2 function in vivo. 相似文献