Local cell metrics: a novel method for analysis of cell-cell interactions

<p>Abstract</p> <p>Background</p> <p>The regulation of many cell functions is inherently linked to cell-cell contact interactions. However, effects of contact interactions among adherent cells can be difficult to detect with global summary statistics due to the localized nature and noise inherent to cell-cell interactions. The lack of informatics approaches specific for detecting cell-cell interactions is a limitation in the analysis of large sets of cell image data, including traditional and combinatorial or high-throughput studies. Here we introduce a novel histogram-based data analysis strategy, termed local cell metrics (LCMs), which addresses this shortcoming.</p> <p>Results</p> <p>The new LCM method is demonstrated via a study of contact inhibition of proliferation of MC3T3-E1 osteoblasts. We describe how LCMs can be used to quantify the local environment of cells and how LCMs are decomposed mathematically into metrics specific to each cell type in a culture, e.g., differently-labelled cells in fluorescence imaging. Using this approach, a quantitative, probabilistic description of the contact inhibition effects in MC3T3-E1 cultures has been achieved. We also show how LCMs are related to the naïve Bayes model. Namely, LCMs are Bayes class-conditional probability functions, suggesting their use for data mining and classification.</p> <p>Conclusion</p> <p>LCMs are successful in robust detection of cell contact inhibition in situations where conventional global statistics fail to do so. The noise due to the random features of cell behavior was suppressed significantly as a result of the focus on local distances, providing sensitive detection of cell-cell contact effects. The methodology can be extended to any quantifiable feature that can be obtained from imaging of cell cultures or tissue samples, including optical, fluorescent, and confocal microscopy. This approach may prove useful in interpreting culture and histological data in fields where cell-cell interactions play a critical role in determining cell fate, e.g., cancer, developmental biology, and tissue regeneration.</p

Preharvest or a combination of preharvest and postharvest treatments with methyl jasmonate reduced chilling injury, by maintaining higher unsaturated fatty acids, and increased aril colour and phenolics content in pomegranate

In the present research the effects of preharvest 5mM methyl jasmonate (MeJa) treatments, alone (Pre) or in combination with postharvest 5mM MeJa treatment (Pre+Post), on reducing chilling injury (CI) of pomegranate during 90 d of storage at 2 °C plus 3 d at 20 °C and its relationship with changes in fatty acid composition of cell membranes were assayed. In addition, fruit and aril quality traits, total content in phenolics and anthocyanins and antioxidant activity of the arils were evaluated. Both, external and internal CI symptoms and the increase in ion leakage (IL) were reduced by Pre and Pre+Post MeJa treatments. The major fatty acids in pomegranate husk were palmitic, oleic, linoleic and linolenic acids. MeJa treatments led to higher concentration of unsaturated fatty acids (UFA) at harvest, which wasmaintained at higher levels during storage, while saturated fatty acid (SFA) concentration was lower in treated fruit than in controls. The concentration of total phenolics and anthocyanins were lower in the arils from control fruit than in arils of Pre and Pre+Post treated fruit during the whole storage period. In general, there were no significant differences between Pre and Pre+Post MeJa treatments on their effects on reducing CI, maintaining membrane stability and bioactive compounds with antioxidant activity. Thus, preharvest MeJa treatments may be sufficient to increase the cold storage potential of pomegranate fruit by reducing CI symptoms and enhancing the content bioactive compounds with antioxidant activit

Psychometric validation of an instrument to evaluate the context of quality improvement and accreditation of hospitals

Objective. To adapt and validate an instrument to mea­sure the context factors which favor quality improvement initiatives and accreditation of hospitals. Materials and methods. The model and questionnaire Model for Under­standing Success in Quality (MUSIQ) is adapted and validated for application in Spanish-speaking countries and its specific use in hospital accreditation projects. The theoretical con­struct of its dimensions is assessed by confirmatory factor analysis (Bartlett test and Kaiser-Meyer-Olkim index) and internal consistency (Cronbach’s a), in a study carried out in a sample of 54 hospitals of medium and high complexity in Colombia. Results. Instrument with four dimensions of context (environment, macrosystem, microsystem, quality team), composed of 23 elements that are measured through 35 variables. Factor analysis showed statistical significance and adequacy of the dimensions, which had also good internal consistency. Conclusion. Adapted instrument with useful­ness for measurement of context elements that can promote initiatives of improvement and accreditation in hospitals

Polyamines as an ecofriendly postharvest tool to maintain fruit quality

Polyamines (PAs) are natural compounds involved in a wide range of plant growth and developmental process, such as cell division, dormancy breaking, germination, development of flower buds, fruit set, growth and ripening, as well as in plant responses to environmental stresses including chilling injury. This chapter will focus on the role of PAs in fruit growth and ripening, with special emphasis on the effects of pre- and postharvest PA treatment on fruit quality attributes, bioactive constituents with antioxidant activity, and tolerance of fruit to chilling injury damage. The results of this chapter provide evidence for the numerous beneficial effects of the exogenous PA treatments, both at pre- and postharvest time in fruit quality attributes including their concentration in antioxidant compounds. Taking into account that PAs are naturally occurring molecules their application as pre- or postharvest treatment could be considered as an environmentally compatible tool as they can be metabolized by fruit cells. In addition, it should be pointed out that although exogenous application of PAs enhances their endogenous levels, the concentrations remain far lower than the toxic ones. Since modern agriculture is searching for effective biological molecules with well-known metabolic effects but without toxicological effects, a possible answer may be related to PA treatments

Melatonin Treatment of Apricot Trees Leads to Maintenance of Fruit Quality Attributes during Storage at Chilling and Non-Chilling Temperatures

The effects of preharvest melatonin treatment on apricot crop yield and fruit quality properties at harvest and during storage have not yet been investigated. Apricot trees, of the ‘Colorado’ and ‘Mikado’ cultivars, were sprayed with 0.1 mM melatonin at three key points of fruit development. Fruit were harvested at commercial ripening stage and yield was higher in melatonin treated trees than in the controls. Fruit were stored at 1 and 8 °C for 21 and 28 days, respectively. Samples were taken weekly and left at 20 °C for 1 day. Weight losses, as well as reduction in firmness and acidity, were delayed in fruits from melatonin treated trees, showing an effect of treatment on delaying the postharvest ripening process, which was attributed to a reduced ethylene production in both cultivars and at both storage temperatures. In addition, chilling injury symptoms were observed in apricots stored at 1 °C, which were reduced by preharvest melatonin treatment. Moreover, apricot from melatonin-treated fruit retained higher total phenolic content than the controls after 14 days of storage, although the phenolic profile was not affected by treatment. Thus, melatonin could be a useful tool for practical purposes to improve apricot crop yield and maintain fruit quality properties during storag

Sensory, Nutritive and Functional Properties of Sweet Cherry as Affected by Cultivar and Ripening Stage

In this article 11 commercial sweet cherry cultivars were selected to evaluate sensory, nutritive and functional properties over the maturation process on tree. Fruit quality was significantly different among cultivars and maturity stages at harvest, with the highest quality scores being found in the harvest which was 4 days beyond current commercial harvest maturity for all the cultivars tested. Taking into account all of the measured parameters (weight, firmness, color, acidity and total soluble solids), ‘NY-6479’, ‘Prime Giant’ and ‘Sunburst’ could be classified as having the highest quality in terms of sensory attributes. However, ‘Cristalina’ and ‘Sonata’ had the highest functional quality, as determined by the measurement of bioactive compound content and antioxidant capacity. We conclude that a delay of a few days in harvesting of sweet cherries would lead to achieve maximal nutritional (highest sugar and organic acid contents), sensory (greatest firmness and color development) and functional (greatest phenolics content, anthocyanins and antioxidant capacity) quality to provide both eating enjoyment and health benefits to the consume

Influence of flower head order on phenolic content and quality of globe artichoke at harvest and during twenty-one days of cold storage

Artichoke is one of the vegetables with higher content in phenolic compounds, which are responsible for their taste, flavor and health beneficial effects. However, phenolic profile and concentration depends on many factors, such as genotype, harvest date, and environmental and agronomical conditions. The main aim of this study was to perform a phytochemical characterization of artichoke heads, based on their position on plant (main, secondary and tertiary head) and harvest date, during a complete growing season. Results showed that total identified polyphenol concentration was higher in tertiary heads than secondary and main heads, due to their higher concentration in hydroxycinnamic acid and luteolin derivatives. On the other hand, two postharvest storage experiments with main, secondary and tertiary artichoke heads, harvested in winter and spring, were performed. In addition, tertiary head showed the lowest weight, firmness losses and respiration rate during cold storage which could be attributed to their higher antioxidant compounds. In conclusion, tertiary heads have a greater aptitude to be stored at low temperature from harvesting to consumption since they maintained the quality properties for longer period of time and had higher content of bioactive compounds. However, main artichokes are the most appreciated by consumers due to their larger siz

Preharvest application of methyl salicylate, acetyl salicylic acid and salicylic acid alleviated disease caused by Botrytis cinerea through stimulation of antioxidant system in table grapes

The main goal of this study was to describe impact of preharvest application of methyl salicylate (MeSA), acetyl salicylic acid (ASA) and salicylic acid (SA) on the reduction of disease caused by Botrytis cinerea in two table grape cultivars (‘Crimson’ and ‘Magenta’). Based on previous studies, MeSA and SA were applied at 0.1 and 0.01mM for both cultivars, while ASA was applied at 1mM in ‘Crimson’ and 0.1mM in ‘Magenta’. At time of harvest, berry maturity-quality attributes, bioactive compounds and antioxidant enzymes were determined. In addition, grapes were artificially inoculated with B. cinerea spores, and the berries were ranked for visual decay incidence after 5 days of inoculation. Salicylates preharvest treatments led to higher total acidity, content of bioactive compounds and activity of antioxidant enzymes in treated than in control berries. The application of salicylate derivatives induced resistance to B. cinerea spoilage, since higher percentage of berries with no symptoms was observed and on the contrary, the highest percentages of berries were obtained in control grapes. All preharvest treatments with SA, ASA and MeSA alleviated postharvest disease caused by B. cinerea probably due to increasing levels of phenolic compounds and activity of antioxidant enzymes, although the best results were obtained with MeSA at 0.1 mM. Also, for this treatment and dose, higher quality properties, such as higher concentrations of ascorbic, succinic and fumaric acids, were observed compared with no treated-grapes

Methyl jasmonate effects on table grape ripening, vine yield, berry quality and bioactive compounds depend on applied concentration

In the present research the effect of preharvest metyil jasmonate (MeJA) treatment on the ripening process and fruit quality parameters at harvest was evaluated, for the first time, in two table grape cultivars, ‘Magenta’ and ‘Crimson’, during two years, 2016 and 2017. MeJA treatments (applied when berry volume was ca. 40% of its final one, at veraison and 3 days before the first harvest date) affected grape ripening process and vine yield differently depending on applied concentration. Thus, MeJA at 5 and 10mM delayed berry ripening and decreased berry weight and volume as well as vine yield, in a dose-dependent way, in both cultivars, although the effect on ‘Crimson’ was more dramatic than in ‘Magenta’. However, treatments with MeJA at 1, 0.1 and 0.01mM accelerated ripening and increased total phenolics and individual anthocyanin concentrations, the major effects being obtained with 0.1mM concentration. In addition, total soluble solids (TSS) and firmness levels were also increased by these MeJA treatments. These results might have a great agronomic and commercial importance since fruit with higher size and harvested earlier would reach higher prizes at markets and berries with higher firmness and TSS would be more appreciated by consumers. Moreover, MeJA treatments increased the content of antioxidant compounds, such as phenolics and individual anthocyanins, leading to enhance the homogeneous pigmentation of the whole cluster, with additional effects on increasing the health beneficial effects of grape consumption

The Effects of Salicylic Acid and Its Derivatives on Increasing Pomegranate Fruit Quality and Bioactive Compounds at Harvest and During Storage

In the present research two experiments were performed to evaluate the effect of preharvest salicylic acid (SA), acetyl salicylic acid (ASA), and methyl salicylate (MeSa), applied as a foliar spray to pomegranate “Mollar de Elche,” on crop yield, fruit quality parameters, and bioactive compounds at harvest and during storage. In the 2017 experiment, trees were treated with SA, ASA, and MeSa at 1, 5, and 10 mM and a higher crop yield (kg tree1 and number of harvested fruit tree1) and quality parameters (firmness, aril color, and individual sugars and organic acids) at harvest were obtained, as well as a higher concentration of phenolics, anthocyanins, and ascorbic acid. The best results were achieved with 10 mM dose of the three assayed compounds, which was chosen for the 2018 experiment, and results for crop yield and fruit quality attributes were confirmed. These quality traits and the concentration of phenolics, anthocyanins, and ascorbic acid were maintained at higher levels in pomegranate fruit from treated trees than in controls during prolonged storage at 10 C. In addition, the effects of salicylate treatments on increasing total and individual anthocyanin concentration in pomegranate arils led to arils with a deeper red color (Graphical Abstract) and, in turn, fruit that would be more appreciated in the international market. This fact, together with the increased crop yield, would contribute to the increased profit of this crop. Thus, pre-harvest treatment with salicylates, and especially SA at 10 mM concentration, could be a safe, natural, and new tool to improve fruit quality and its content on antioxidant compounds with health beneficial effects (namely, ascorbic acid, phenolics, and anthocyanins) at harvest and during storage