Graduate students in chemistry, and in biological and biomedical fields must learn the fundamentals and practices of peptide and protein chemistry as early as possible. A project‐oriented approach ...was conducted by first‐year M.Sc and Ph.D students in biological sciences. A blind glass slide containing a cellular smear and an aqueous cellular extract were offered to the students. Qualitative and quantitative cell morphological parameters were analyzed by atomic force microscopy. The fractionation of the aqueous extract was conducted by reversed‐phase chromatography followed by analysis of the isolated and partially purified proteins and peptides by mass spectrometry (MS). The proteins were treated by peptidases and the obtained peptide fragments were sequenced by de novo MS/MS, together with peptides already present in the extract. The most abundant protein fractions were identified as the alpha and beta chains of hemoglobin from an amphibian of the Leptodactylus genera. Two of the peptides sequenced by the students were synthesized by the solid‐phase methodology, one of those being obtained by the split‐and‐pool library synthesis method. Thus, the students were able to learn some advanced principles and practices of protein chemistry and bionanotechnology in a 6‐weeks project‐oriented approach.
Plants have developed various mechanisms to respond specifically to each biotrophic attack. It has been shown that the electrical signals emitted by plants are associated with herbivory stress ...responses and can lead to the activation of multiple defences. Bt cotton is a genetically modified pest-resistant plant that produces an insecticide from Bacillus thuringiensis (Bt) to control Lepidopteran species. Surprisingly, there is no study-yet, that characterizes the signalling mechanisms in transgenic cotton plants attacked by non-target insects, such as aphids. In this study, we characterized the production of electrical signals on Bt and non-Bt cotton plants infested with Aphis gossypii and, in addition, we characterized the dispersal behaviour of aphids to correlate this behaviour to plant signalling responses. Electrical signalling of the plants was recorded with an extracellular measurement technique. Impressively, our results showed that both Bt and non-Bt cotton varieties, when attacked by A. gossypii, emitted potential variation-type electrical signals and clearly showed the presence of distinct responses regarding their perception and the behaviour of aphids, with evidence of delay, in terms of signal amount, and almost twice the amount of Cry1F protein was observed on Bt cotton plants at the highest density of insects/plant. We present in our article some hypotheses that are based on plant physiology and insect behaviour to explain the responses found on Bt cotton plants under aphid stress.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
For a long time, electrical signaling was neglected at the expense of signaling studies in plants being concentrated with chemical and hydraulic signals. Studies conducted in recent years have ...revealed that plants are capable of emitting, processing, and transmitting bioelectrical signals to regulate a wide variety of physiological functions. Many important biological and physiological phenomena are accompanied by these cellular electrical manifestations, which supports the hypothesis about the importance of bioelectricity as a fundamental 'model' for response the stresses environmental and for activities regeneration of these organisms. Electrical signals have also been characterized and discriminated against in genetically modified plants under stress mediated by sucking insects and/or by the application of systemic insecticides. Such results can guide future studies that aim to elucidate the factors involved in the processes of resistance to stress and plant defense, thus aiding in the development of successful strategies in integrated pest management. Therefore, this mini review includes the results of studies aimed at electrical signaling in response to biotic stress. We also demonstrated how the generation and propagation of electrical signals takes place and included a description of how these electrical potentials are measured.
Plants and insects are parts of a complex system that involves interactions among many trophic levels, and it is important to understand the nature of such interactions. In the complex of ...interactions involving aphids and transgenic cotton expressing Bacillus thuringiensis, both the spraying of neonicotinoids and the occurrence of predatory coccinellids are common. However, there are gaps regarding the knowledge about possible impacts of neonicotinoids on physiological variables of the host plant and behavioural traits of the aphid (Aphis gossypii) and predator (Cycloneda sanguinea). Therefore, this study aimed to highlight the photosynthetic and electrical responses of the plant to the stress caused by the aphid attack combined with the stress generated by the use of imidacloprid in Bt and non-Bt cotton (Gossypium hirsutum L.) cultivars and to evaluate how this stress can influence the behavioural ecology of the predator and prey. Chlorophyll a fluorescence tests, dark respiration and electrophysiology on non-Bt and Bt cotton were carried out, the behaviour of the prey and predator was also evaluated with a video capture system. Our research is a study model that generates insights about possible impacts when using Imidacloprid without the occurrence of the pest on the plant, because the exposure of non-Bt and Bt cotton plants and the predator to imidacloprid unnecessarily, may result in stress on the physiology of the cotton plants and on the behaviour of the predator.
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•Cotton plants, aphids and coccinellid predators are parts of a complex system that involves important interactions.•The understanding of such interactions must consider insecticide use.•Imidacloprid exposure on Bt and non-Bt cotton plants, and C. sanguinea in the aphid absence, result in stress on the plant physiology and on the predator mobility.•Our results evidence impacts when using Imidacloprid in cases of non-occurrence of the aphid.
Imaging Findings in Takayasu's Arteritis Gotway, Michael B; Araoz, Philip A; Macedo, Thanila A ...
American journal of roentgenology (1976),
06/2005, Letnik:
184, Številka:
6
Journal Article
Recenzirano
The objective of our study was to evaluate the clinical usefulness of cross-sectional imaging for establishing the diagnosis of Takayasu's arteritis (TA), an inflammatory vascular disorder that ...produces arterial stenoses and aneurysms primarily involving the thoracoabdominal aorta and its branches and the pulmonary arteries.
CT and MRI findings of TA include vascular wall thickening and enhancement early in the disease, and arterial stenoses, occlusions, and aneurysms later in the disease. Cross-sectional imaging is useful for establishing the diagnosis of TA and for showing response to nonsurgical therapy or for planning a surgical intervention.
Abstract
Introduction: 2D cells lack cell-cell and cell-extracellular matrix interactions, critical for regulating cell functions. 3D cells in matrigel, hydrogels, hanging drops, and micropatterned ...plates can overcome these drawbacks but suffer from long spheroid formation times with variable efficiency. Magnetic 3D bioprinting (M3DB) can circumvent these issues by utilizing nanoparticles-magnetized cells for spheroid formation. M3DB spheroids can emulate tissue microenvironments and exhibit higher resistance to toxic agents than their 2D counterparts. It is, however, unclear how M3DB spheroids influence toxic responses in cells via metabolic perturbations. We employed Stable Isotope-Resolved Metabolomics (SIRM) with 13C6-glucose to map metabolic networks in 2D cells and M3DB spheroids formed from lung (A549) and pancreatic (PANC1) adenocarcinoma cells ± anti-cancer Na2SeO3.
Experimental: A549 and PANC1 cells were grown in 2D culture in DMEM to ca. 70% confluence for loading with magnetic nanoparticles (Nanoshuttle, N3D Biosciences), detached, and placed in cell repellent plates for spheroid formation. Spheroids were then treated in U-13C-glucose ± Na2SeO3 for 24 h. Metabolites were extracted in cold 70% methanol and analyzed by IC-FTMS and NMR 1,2 to determine the 13C isotopologue and isotopomer distributions for reconstructing metabolic networks.
Findings: We found that spheroids remained metabolically active in 10-day cultures. 13C label incorporation into glycolytic, Krebs cycle, and nucleotide metabolites was similar between spheroids and their 2D counterparts. The exceptions were higher 13C-ribose incorporation into uracil nucleotides in 2D than M3DB cultures of A549 cells and activation of gluconeogenesis in PANC1 M3DB spheroids. Selenite inhibited these pathways less in spheroids than 2D counterparts for both cell lines, consistent with the growth changes. Thus, the increased resistance of cancer spheroids to selenite may be mediated by these metabolic pathways central to growth and survival.
Conclusions: 3D spheroids offer convenient models with more relevant 3-D architectures for preclinical studies on metabolic reprogramming and drug response of human cancer cells and cancer-stromal cell co-cultures. Spheroid formation in the M3DB system is fast, high throughput without matrix interferences for metabolic analyses.
Supported by NCI P01CA163223-01A1, P30 CA177558 and NIDDK 1U24DK097215-01A1
1. Sun RC, Fan TW-M, Deng P, et al. Liquid diet delivery of stable isotopes into PDX mice for deep metabolic pathway tracing. Nat. Commun. 2017;9:1646.
2. Fan TW-M, Warmoes MO, Sun Q, et al. Distinctly perturbed metabolic networks underlie differential tumor tissue damages induced by immune modulator β-glucan in a two-case ex vivo non-small cell lung cancer study. CSH Molec Case Studies 2016;2:a000893.
Citation Format: Teresa W. Fan, Salim S. El-Amouri, Jessica K. Macedo, Qiushi Sun, Andrew N. Lane. Mapping metabolic networks and drug resistance in 3D spheroids using stable isotope-resolved metabolomics (SIRM) abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5028.
ABSTRACT
Physical modelling of cracked/fractured media using downscaled laboratory experiments has been used with great success as a useful alternative for understanding the effect of anisotropy in ...the hydrocarbon reservoir characterization and in the crustal and mantle seismology. The main goal of this work was to experimentally verify the predictions of effective elastic parameters in anisotropic cracked media by Hudson and Eshelby–Cheng's effective medium models. For this purpose, we carried out ultrasonic measurements on synthetic anisotropic samples with low crack densities and different aspect ratios. Twelve samples were prepared with two different crack densities, 5% and 8%. Three samples for each crack density presented cracks with only one crack aspect ratio, whereas other three samples for each crack density presented cracks with three different aspect ratios in their composition. It results in samples with aspect ratio values varying from 0.13 to 0.26. All the cracked samples were simulated by penny‐shaped rubber inclusions in a homogeneous isotropic matrix made with epoxy resin. Moreover, an isotropic sample for reference was constructed with epoxy resin only. Regarding velocity predictions performed by the theoretical models, Eshelby–Cheng shows a better fit when compared with the experimental results for samples with single and mix crack aspect ratio (for both crack densities). From velocity values, our comparisons were also performed in terms of the ε, γ, and δ parameters (Thomsen parameters). The results show that Eshelby–Cheng effective medium model fits better with the measurements of ε and γ parameters for crack samples with only one type of crack aspect ratio.
Surveillance systems for West Nile virus (WNV) combine several methods to determine the location and timing of viral amplification. The value of each surveillance method must be measured against its ...efficiency and costs to optimize integrated vector management and suppress WNV transmission to the human population. Here we extend previous comparisons of WNV surveillance methods by equitably comparing the most common methods after standardization on the basis of spatial sampling density and costs, and by estimating optimal levels of sampling effort for mosquito traps and sentinel chicken flocks. In general, testing for evidence of viral RNA in mosquitoes and public-reported dead birds resulted in detection of WNV approximately 2-5 weeks earlier than serological monitoring of sentinel chickens at equal spatial sampling density. For a fixed cost, testing of dead birds reported by the public was found to be the most cost effective of the methods, yielding the highest number of positive results per $1000. Increased spatial density of mosquito trapping was associated with more precise estimates of WNV infection prevalence in mosquitoes. Our findings also suggested that the most common chicken flock size of 10 birds could be reduced to six to seven without substantial reductions in timeliness or sensitivity. We conclude that a surveillance system that uses the testing of dead birds reported by the public complemented by strategically timed mosquito and chicken sampling as agency resources allow would detect viral activity efficiently in terms of effort and costs, so long as susceptible bird species that experience a high mortality rate from infection with WNV, such as corvids, are present in the area.
•DPSIR survey to help self-assessment of waste pickers’ cooperatives.•Nine-dimensional questionnaire to evaluate performance of cooperatives.•Pressure indicators were scored and linked to states, ...impacts and responses.•Quality index is automatically presented with guidance for improvement.•A case study is used to illustrate the proposed survey.
Cooperatives of waste pickers play a critical role in municipal solid waste management, contributing to public health, sanitation, and the environment by promoting resource circulation and reducing the amount of recyclable waste disposed of in landfills. Despite this, the majority of cooperatives lack an organized physical infrastructure and operational protocols for integrated waste management, which includes the stages of sorting, classification, processing, and marketing recyclable waste. In this work, an optimized survey was developed to assist waste pickers’ cooperatives in self-assessing their social, environmental, and economic performances. A questionnaire with nine dimensions was developed and automated to connect 16 driving forces (D), 74 pressure indicators (P), 23 states (S), 35 impacts (I), and 38 responses (R). The only action required was to choose each pressure indicator and apply the appropriate score level based on the cooperative's data analysis. The procedure eliminates subjective interpretation and identifies all indicators that require further consideration and discussion. As a result, the cooperative is able to propose highly targeted improvement measures. To demonstrate the benefits of the tool, the survey was applied in a waste picker's cooperative in a municipality in Brazil.
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COVID-19 vaccines have been critical for protection against severe disease following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) but gaps remain in our understanding ...of the immune responses that contribute to controlling subclinical and mild infections.
Vaccinated, active-duty US military service members were enrolled in a non-interventional, minimal-risk, observational study starting in May, 2021. Clinical data, serum, and saliva samples were collected from study participants and were used to characterise the humoral immune responses to vaccination and to assess its impact on clinical and subclinical infections, as well as virologic outcomes of breakthrough infections (BTI) including viral load and infection duration.
The majority of VIRAMP participants had received the Pfizer COVID-19 vaccine and by January, 2022, N = 149 had a BTI. The median BTI duration (PCR+ days) was 4 days and the interquartile range was 1–8 days. Participants that were nucleocapsid seropositive prior to their BTI had significantly higher levels of binding and functional antibodies to the spike protein, shorter median duration of infections, and lower median peak viral loads compared to seronegative participants. Furthermore, levels of neutralising antibody, ACE2 blocking activity, and spike-specific IgA measured prior to BTI also correlated with the duration of infection.
We extended previous findings and demonstrate that a subset of vaccine-induced humoral immune responses, along with nucleocapsid serostatus are associated with control of SARS-CoV-2 breakthrough infections in the upper airways.
This work was funded by the DoD Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) in collaboration with the Defense Health Agency (DHA) COVID-19 funding initiative for the VIRAMP study.
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