scholarly journals Seasonal Variation in Host Susceptibility to Fusarium Canker in Young Almond Trees

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 772-779
Author(s):  
Abigail J. Stack ◽  
Meera Madra ◽  
Thomas R. Gordon ◽  
Richard M. Bostock
Keyword(s):  
Cold Storage ◽  
Fusarium Species ◽  
Lesion Size ◽  
Host Susceptibility ◽  
Seasonal Effect ◽  
Canker Disease ◽  
Almond Trees ◽  
Bare Root ◽  
The Impact

Loss of water that reduces the relative water content (RWC) of bark can occur during processing, cold storage, and planting of bare-root stone fruit trees. In California nurseries and newly planted orchards, this stress can predispose young almond trees (Prunus dulcis) to a canker disease caused primarily by Fusarium species. While reduced bark RWC contributes to disease development, anecdotal observations suggest a seasonal effect on host physiology may also influence disease severity. We evaluated the effect of season and the impact of drying and reduced RWC on susceptibility of almond branch segments excised from orchard trees (cv. Nonpareil) to Fusarium acuminatum, Fusarium avenaceum, Fusarium brachygibbosum, and Fusarium californicum sp. nov. With lesion size as the criterion, excised inoculated branch segments were most susceptible in spring, of intermediate susceptibility during winter dormancy, and least susceptible during summer and fall. Consistent with an earlier study, branches with RWC between 80 and 85% yielded lesions that were significantly larger than lesions from branches with bark that was above or below that range. However, the effect of reduced bark moisture on lesion size was only apparent in the spring. These results affirm the importance of avoiding conditions that diminish moisture status in bare-root almond trees in Fusarium canker disease management, especially during transport and planting operations in the spring, a period of high physiological vulnerability. California nurseries apply fungicides to bare-root trees prior to cold storage to reduce “mold” growth. Of eight fungicides currently registered for use on almond trees, fludioxonil (Scholar), fluopyram/trifloxystrobin (Luna Sensation), and fluxapyroxad/pyraclostrobin (Merivon) were most inhibitory to in vitro mycelial growth of F. acuminatum, F. avenaceum, and F. brachygibbosum. However, our almond branch disease assay did not demonstrate preventive or curative fungicide action against infections by F. acuminatum or F. avenaceum.

Genetic diversity and potential inoculum sources of Fusarium species causing cankers in bareroot-propagated almond trees in California nurseries

Plant Disease ◽  
2021 ◽  
Author(s):  
Abigail Justine Stack ◽  
Stephen Mark Marek ◽  
Thomas Gordon ◽  
Richard M. Bostock
Keyword(s):  
Cold Storage ◽  
Fusarium Species ◽  
Storage Facility ◽  
Clonal Lineage ◽  
Fusarium Spp ◽  
Inoculum Sources ◽  
Canker Disease ◽  
Fusarium Acuminatum ◽  
Almond Trees ◽  
Rotation Crops

Previous research determined that Fusarium acuminatum and Fusarium avenaceum are important causal agents of a canker disease in bareroot-propagated fruit and nut trees in California that emerges during cold-storage or after transplanting. The disease largely disappeared after 2001, but it reemerged in 2011 in almond trees in at least one nursery. This motivated further study of the etiology and epidemiology of the disease by undertaking studies to determine distribution of the pathogens throughout almond nursery propagation systems and trace possible sources of inoculum. Research initiated in 2013 detected pathogenic Fusarium spp. throughout the almond propagation system, including in healthy trees, in soils, on wheat rotation crops, on equipment, and in the cold storage facility air. In addition to the two Fusarium spp. implicated previously, Fusarium brachygibbosum and a new Fusarium species, Fusarium californicum, were found to be pathogenic on almond trees. Multi-locus sequence typing and somatic compatibility testing confirmed that isolates within a species collected from different materials in the nursery were all highly genetically similar and likely of one clonal lineage. These findings affirm that equipment surfaces, wheat rotation crops, soil, cold storage facility air, and asymptomatic almond tree materials (i.e., rootstock cuttings, budwood, and scions) can potentially contribute inoculum to increase disease prevalence and severity.

scholarly journals Influence of Pasteurization and Storage on Dynamic In Vitro Gastric Digestion of Milk Proteins: Quantitative Insights Based on Peptidomics

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 998 ◽  
Author(s):  
Xing Li ◽  
Yuxiang Gu ◽  
Shudong He ◽  
Olayemi Eyituoyo Dudu ◽  
Qiming Li ◽  
...  
Keyword(s):  
Cold Storage ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Milk Proteins ◽  
Hydrolysis Rate ◽  
Gastric Digestion ◽  
Pasteurized Milk ◽  
The Impact ◽  
And Storage

It is important to evaluate the nutritional quality of milk during the shelf-life, especially during home storage, from a consumer viewpoint. In this study, we investigated the impact of pasteurization (85 °C/15 s) and subsequent storage (at 4 °C for 7 days) on the coagulation behavior of milk and protein digestibility in a dynamic in vitro gastric digestion test. A high level of hydration in curd formed in pasteurized milk upon 7-day cold storage compared to raw and pasteurized milk, indicating fast pepsin diffusion in the interior of curds, increasing the hydrolysis rate. The digesta collected at various time points throughout the gastric digestion were studied using o-phthaldialdehyde (OPA), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), liquid chromatography tandem mass spectrometry (LC-MS/MS), and amino acid analysis. These results showed that milk proteins were hydrolyzed quickly upon a long period of cold storage. Additionally, qualitative and quantitative results obtained using LC-MS/MS exhibited significant differences between samples, especially in pasteurized milk upon cold storage. Processing and storage played a decisive role in bioactive peptide generation. Such knowledge could provide insights into and directions for the storage of pasteurized milk for further clinical studies on protein bioavailability and the generation of bioactive peptides for desired health outcomes.

1322Impact of system impedance in ablation-index guided lesion formation in an in vitro model

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Lozano-Granero ◽  
J Moreno Planas ◽  
R Matia Frances ◽  
A Hernandez Madrid ◽  
I Sanchez Perez ◽  
...  
Keyword(s):  
Contact Force ◽  
Lesion Size ◽  
Lesion Volume ◽  
Application Time ◽  
Lesion Formation ◽  
Running Water ◽  
High Impedance ◽  
Ablation Index ◽  
The Impact

Abstract Funding Acknowledgements Beca de la Sección de Electrofisiología y Arritmias para formación en investigación post-residencia en centros españoles INTRODUCTION Ablation Index and Lesion Size Index are novel markers of ablation lesion quality that incorporate power (W), contact force (CF), and time (T) in a weighted formula to accurately estimate lesion size. While LSI includes system impedance (I) in the formula, this parameter is not considered for AI calculation. PURPOSE The aim of our study was to analyse the impact of I in lesion formation. METHODS Radiofrequency (RF) lesions were created on porcine myocardial slabs by using an open-tip irrigated catheter with real-time monitoring of CF (a TactiCath™ Quartz Contact Force Ablation Catheter for LSI-guided lesions and a ThermoCool® SmartTouch® Catheter for AI-guided lesions). Catheters were mounted in an articulated arm and manually maneuvered over a platform placed within a tank filled with either a low impedance medium (saline solution) or a high impedance medium (running water) with a heating pump to produce non-pulsatile flow directed perpendicularly to the myocardium surface at a rate of 5 l/min and a temperature of 37ºC. For each catheter and medium, ten lesions were performed with a CF of 20 grams and a W of 25, 30, 35 and 40 watts aiming at a LSI of 5 or a AI of 400 (recommended targets for posterior wall pulmonary vein isolation for each index). After RF delivery, the myocardium was cross-sectioned at the level of each lesion and its blanched zone was measured with a dial calliper with a 0.1 mm resolution (image, panel A). Lesion volume was calculated using width and depth, according to a validated formula (image, panel B). RESULTS No difference in application time was noted in the AI-guided lesions depending on the medium (23.8 ± 1.6s, 17.2 ± 1.4s, 13.7 ± 0.8s and 12.2 ± 0.7s for 25W, 30W, 35W and 40W, respectively) while a significant reduction in application time was noted in the LSI-guided lesions performed in a low I medium (93.8 ± 6.6 ohms; 17.9 ± 1.9s, 11.3 ± 3.7s, 9.1 ± 0.9s and 7.3 ± 0.5s for 25W, 30W, 35W and 40W) compared with those performed in a high impedance medium (132.4 ± 6.6 ohms; 27.3 ± 1.4s, 17.9 ± 2.5s, 15.5 ± 1.4 and 13 ± 1.2 for the same programmed W (p < 0.0001 for all comparisons). Both catheters showed differences in lesion size according to the I, with lower lesion volumes in the low I medium and higher lesion volumes in the high I medium. Although globally smaller in size, higher lesion volumes were noted in the AI-guided lesions compared to LSI-guided lesions in a low I medium (image, panel C). On the contrary, a better performance of the LSI-guided lesions was observed in the high I medium (image, panel D). CONCLUSIONS System impedance affected lesion size both in LSI-guided an AI-guided ablation lesions, with smaller lesions seen in a lower I medium. Further studies are needed to assess the clinical relevance of this findings in an in-vivo scenario. Abstract Figure.

scholarly journals Fusarium spp., Cylindrocarpon spp., and Environmental Stress in the Etiology of a Canker Disease of Cold-Stored Fruit and Nut Tree Seedlings in California

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Stephen M. Marek ◽  
Mohammad A. Yaghmour ◽  
Richard M. Bostock
Keyword(s):  
Cold Storage ◽  
Signs And Symptoms ◽  
Tissue Loss ◽  
Tree Seedlings ◽  
Canker Disease ◽  
Almond Trees ◽  
Asymptomatic Infections ◽  
Canker Development ◽  
Stem Segments ◽  
Increased Susceptibility

The principal objective of this study was to determine the etiology of a canker disease in dormant stone fruit and apple tree seedlings maintained in refrigerated storage that has significantly impacted California fruit and nut tree nurseries. Signs and symptoms of the disease develop during storage or soon after planting, with subsequent decline and death of young trees. Isolations from both diseased and healthy almond and apple trees and Koch's postulates using stem segments of desiccation-stressed almond trees as hosts implicated Fusarium avenaceum and F. acuminatum as the primary causal agents. F. solani, Ilyonectria robusta, and Cylindrocarpon obtusiusculum were also capable of causing similar symptoms but were less frequently encountered in isolations of diseased tissue. Loss of bark turgidity in excised almond stem segments, as can occur in cold-stored seedlings, correlated with increased susceptibility to F. acuminatum, with maximum canker development occurring after relative bark turgidity dropped below a threshold of approximately 86%. Healthy almond trees, almond scion budwood, and a wheat cover crop used in fields where tree seedlings were grown and maintained until cold storage all possessed asymptomatic infections of F. acuminatum, F. avenaceum, and C. obtusiusculum as determined by activation following overnight freezing, cold storage, or desiccation.

scholarly journals Time-dependent and force-dependent vasoreactivity of isolated human umbilical arteries

2020 ◽  
Vol 51 (3) ◽  
pp. 134-140
Author(s):  
Đorđe Đukanović ◽  
Milica Gajić ◽  
Ranko Škrbić
Keyword(s):  
Incubation Period ◽  
Cold Storage ◽  
Dose Response ◽  
In Vitro Studies ◽  
Time Dependent ◽  
Response Curves ◽  
Experimental Conditions ◽  
Umbilical Arteries ◽  
The Impact

Background/Aim: There have been different experimental conditions for in vitro studies on human umbilical arteries (HUA) in tissue bath system. This diversity was mainly reflected in variables such as stretching tension, incubation period and initial constriction challenging with potassium (KCl). The aim of the study was to establish optimal experimental conditions which will provide better responsiveness of HUA preparations, as well as to examine the impact of 24 h cold storage on viability and responsiveness of HUA to KCl and serotonin. Methods: The KCl-induced constrictions at different stretching tensions (0.5 g, 1.0 g, 2.0 g, 4.0 g), incubation times (30 min, 60 min, 120 min), and after multiple initial constriction challenging were compared. Dose response curves for serotonin were obtained under different conditions (1.0 g and 60 min vs. 2.0 g and 120 min). The influence of 24 h cold storage on KCland serotonininduced vasoconstriction of HUA preparations was examined as well. Results: The strongest constrictions induced by serotonin or KCl were obtained when preparations were adjusted at 2.0 g and incubated for 120 min. The KCl-induced constrictions observed after 120 min were statistically higher (p < 0.05) when preparations were challenged three times (30 min, 60 min, 120 min), compared to those challenged only once. The preparations that were stored at 4 ⁰C for 24 h showed significantly stronger serotonin-induced constrictions (p < 0.01). The cold storage had no influence on KCl-induced constriction. Conclusion: For performing in vitro studies on HUA preparations in tissue bath, we propose stretching tension of 2.0 g, incubation period of 120 min and multiple initial constriction challenging with KCl as optimal experimental condition. We also showed that HUA preparations retained functional viability even after 24 h of cold storage.

scholarly journals Considerations for Thermal Injury Analysis for RF Ablation Devices

2010 ◽  
Vol 4 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Isaac A. Chang
Keyword(s):  
Thermal Injury ◽  
Tissue Injury ◽  
Recursive Algorithm ◽  
Geometric Model ◽  
Volume Measurement ◽  
Lesion Size ◽  
Voltage Source ◽  
Lesion Volume ◽  
The Impact

Background: The estimation of lesion size is an integral part of treatment planning for the clinical applications of radiofrequency ablation. However, to date, studies have not directly evaluated the impact of different computational estimation techniques for predicting lesion size. In this study, we focus on three common methods used for predicting tissue injury: (1) iso-temperature contours, (2) Cumulative equivalent minutes, (3) Arrhenius based thermal injury. Methods: We created a geometric model of a multi-tyne ablation electrode and simulated thermal and tissue injury profiles that result from three calculation methods after 15 minutes exposure to a constant RF voltage source. A hybrid finite element technique was used to calculate temperature and tissue injury. Time-temperature curves were used in the assessment of iso-temperature thresholds and the method of cumulative equivalent minutes. An Arrhenius-based formulation was used to calculate sequential and recursive thermal injury to tissues. Results: The data demonstrate that while iso-temperature and cumulative equivalent minute contours are similar in shape, these two methodologies grossly over-estimate the amount of tissue injury when compared to recursive thermal injury calculations, which have previously been shown to correlate closely with in vitro pathologic lesion volume measurement. In addition, Arrhenius calculations that do not use a recursive algorithm result in a significant underestimation of lesion volume. The data also demonstrate that lesion width and depth are inadequate means of characterizing treatment volume for multi-tine ablation devices. Conclusions: Recursive thermal injury remains the most physiologically relevant means of computationally estimating lesion size for hepatic tumor applications. Iso-thermal and cumulative equivalent minute approaches may produce significant errors in the estimation of lesion size.

scholarly journals SARS-CoV-2 variants of concern have acquired mutations associated with an increased spike cleavage

2021 ◽  
Author(s):  
Alba Escalera ◽  
Ana S. Gonzalez-Reiche ◽  
Sadaf Aslam ◽  
Ignacio Mena ◽  
Rebecca L. Pearl ◽  
...  
Keyword(s):  
Cell Entry ◽  
Host Susceptibility ◽  
Spike Protein ◽  
Protein Cleavage ◽  
S Protein ◽  
The Impact ◽  
Viral Cell Entry

For efficient cell entry and membrane fusion, SARS-CoV-2 spike (S) protein needs to be cleaved at two different sites, S1/S2 and S2 by different cellular proteases such as furin and TMPRSS2. Polymorphisms in the S protein can affect cleavage, viral transmission, and pathogenesis. Here, we investigated the role of arising S polymorphisms in vitro and in vivo to understand the emergence of SARS-CoV-2 variants. First, we showed that the S:655Y is selected after in vivo replication in the mink model. This mutation is present in the Gamma Variant Of Concern (VOC) but it also occurred sporadically in early SARS-CoV-2 human isolates. To better understand the impact of this polymorphism, we analyzed the in vitro properties of a panel of SARS-CoV-2 isolates containing S:655Y in different lineage backgrounds. Results demonstrated that this mutation enhances viral replication and spike protein cleavage. Viral competition experiments using hamsters infected with WA1 and WA1-655Y isolates showed that the variant with 655Y became dominant in both direct infected and direct contact animals. Finally, we investigated the cleavage efficiency and fusogenic properties of the spike protein of selected VOCs containing different mutations in their spike proteins. Results showed that all VOCs have evolved to acquire an increased spike cleavage and fusogenic capacity despite having different sets of mutations in the S protein. Our study demonstrates that the S:655Y is an important adaptative mutation that increases viral cell entry, transmission, and host susceptibility. Moreover, SARS-COV-2 VOCs showed a convergent evolution that promotes the S protein processing.

scholarly journals The Lung Mucosa Environment in the Elderly Increases Host Susceptibility to Mycobacterium tuberculosis Infection

2019 ◽  
Vol 220 (3) ◽  
pp. 514-523 ◽  
Author(s):  
Juan I Moliva ◽  
Michael A Duncan ◽  
Angélica Olmo-Fontánez ◽  
Anwari Akhter ◽  
Eusondia Arnett ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
The Elderly ◽  
Surfactant Protein ◽  
Host Susceptibility ◽  
Surfactant Protein D ◽  
Mycobacterium Tuberculosis Infection ◽  
Increased Risk ◽  
The Impact

AbstractAs we age, there is an increased risk for the development of tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) infection. Few studies consider that age-associated changes in the alveolar lining fluid (ALF) may increase susceptibility by altering soluble mediators of innate immunity. We assessed the impact of adult or elderly human ALF during Mtb infection in vitro and in vivo. We identified amplification of pro-oxidative and proinflammatory pathways in elderly ALF and decreased binding capability of surfactant-associated surfactant protein A (SP-A) and surfactant protein D (SP-D) to Mtb. Human macrophages infected with elderly ALF–exposed Mtb had reduced control and fewer phagosome–lysosome fusion events, which was reversed when elderly ALF was replenished with functional SP-A/SP-D. In vivo, exposure to elderly ALF exacerbated Mtb infection in young mice. Our studies demonstrate how the pulmonary environment changes as we age and suggest that Mtb may benefit from declining host defenses in the lung mucosa of the elderly.

Effect of Silver Nanoparticles on Toxigenic Fusarium spp. and Deoxynivalenol Secretion in Some Grains

2018 ◽  
Vol 101 (5) ◽  
pp. 1534-1541 ◽  
Author(s):  
Medhat A El-Naggar ◽  
Aisha M Alrajhi ◽  
Moustafa M Fouda ◽  
Eman M Abdelkareem ◽  
Tamer M Thabit ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Genomic Structure ◽  
Fusarium Species ◽  
Fungal Growth ◽  
In Vitro Study ◽  
Fusarium Spp ◽  
Ag Nps ◽  
The Impact ◽  
Corn Grains

Abstract Background: Deoxynivalenol (DON) is one of the most important fungal mycotoxins excreted by different Fusarium species in many types of grains and food commodities. It has high damage impact on human and animal immune systems. Objective: This in vitro study aimed to evaluate the influence of silver nanoparticles (Ag-NPs) as an inhibitor for the DON toxin excreted from some Fusarium spp., which were isolated from barely, wheat, and corn grains. Methods: Ag-NPs were estimated on Minimum Inhibitory Concentration, using levels of 5, 25, 50, 75, and 100 ppm, while the effect on DON was conducted with ELISA. Tri13 and Tri7 primers were used to evaluate the impact of Ag-NPs on the DNA of tested toxigenic Fusarium isolates. Results: Results revealed that the relative density values (Rd, %) of the isolated Fusarium from barley, wheat, and corn grains were 41.27, 26.47, and 30.76%, respectively. The predominant fungus was F. graminearum and F. culmorum in wheat and barley, respectively. The maximum inhibition diameters used for concentrations were 0.5, 2.8, 3.2, 3.3, and 3.31 mm, respectively. The impact of Ag-NPs on genomic structure was limited. Results demonstrated that Ag-NPs have the ability to reduce the linear growth of Fusarium spp. and eliminate the DON toxin to 34.44, 34.60, and 34.89% at 50, 75, and 100 ppm. Conclusions: Ag-NPs are considered nontransgenic substances, and their impact on Fusarium DNA under tested concentrations has been neglected. Ag-NPs may work as an alternative to fungicides to reduce fungal growth and eliminate DON mycotoxins.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

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