Lipid mediated plant immunity in susceptible and tolerant soybean cultivars in response to Phytophthora sojae colonization and infection

BACKGROUND

Soybean is one of the most cultivated crops globally and a staple food for much of the world's population. The annual global crop losses due to infection by Phytophthora sojae is currently estimated at $20B USD, yet we have limited understanding of the role of lipid mediators in the adaptative strategies used by the host plant to limit infection. Since root is the initial site of this infection, we examined the infection process in soybean root infected with Phytophthora sojae using scanning electron microscopy to observe the changes in root morphology and a multi-modal lipidomics approach to investigate how soybean cultivars remodel their lipid mediators to successfully limit infection by Phytophthora sojae.

RESULTS

The results reveal the presence of elevated biogenic crystals and more severe damaged cells in the root morphology of the infected susceptible cultivar compared to the infected tolerant cultivars. Furthermore, induced accumulation of stigmasterol was observed in the susceptible cultivar whereas, induced accumulation of phospholipids and glycerolipids occurred in tolerant cultivar.

CONCLUSION

The altered lipidome reported in this study suggest diacylglycerol and phosphatidic acid mediated lipid signalling impacting phytosterol anabolism appears to be a strategy used by tolerant soybean cultivars to successfully limit infection and colonization by Phytophthora sojae.

Dynamic interplay of metal and metal oxide nanoparticles with plants: Influencing factors, action mechanisms, and assessment of stimulatory and inhibitory effects

Nanoparticles (NPs) of metals and metal oxides have received increasing attention regarding their characteristic behavior in plant systems. The fate and transport of metal NPs and metal oxide NPs in plants is of emerging concern for researchers because they ultimately become part of the food chain. The widespread use of metal-based NPs (MBNPs) in plants has revealed their beneficial and harmful effects. This review addresses the main factors affecting the uptake, translocation, absorption, bioavailability, toxicity, and accumulation of MBNPs in different plant species. It appraises the mechanism of nanoparticle-plant interaction in detail and provides understanding of the estimation strategies for the associated pros and cons with this interplay. Critical parameters of NPs include, but are not limited to, particle size and shape, surface chemistry, surface charge, concentration, solubility, and exposure route. On exposure to MBNPs, the molecular, physiological, and biochemical reactions of plants have been assessed. We have filled knowledge gaps and answered research questions regarding the positive and negative effects of metal and metal oxide NPs on seed germination, callus induction, growth and yield of plant, nutritional content, antioxidants, and enzymes. Besides, the phytotoxicity, cytotoxicity, genotoxicity, and detoxification studies of MBNPs in plants have been outlined. Furthermore, the recent developments and future perspectives of the two-way traffic of interplay of MBNPs and plants have been provided in this comprehensive review.

New insights into the environmental application of hybrid nanoparticles in metal contaminated agroecosystem: A review

Heavy metals (HMs) contamination in agricultural soils is a major constraint to provide safe food to society. Cultivation of food crops on these soils, channels the HMs into the food chain and causes serious human health and socioeconomic problems. Multiple conventional and non-conventional remedial options are already in practice with variable success rates, but nanotechnology has proved its success due to higher efficiency. It also led the hypothesis to use hybrid nanoparticles (HNPs) with extended benefits to remediate the HMs and supplement nutrients to enhance the crop yield in the contaminated environments. Hybrid nanoparticles are defined as exclusive chemical conjugates of inorganic and/or organic nanomaterials that are combinations of two or more organic components, two or more inorganic components, or at least one of both types of components. HNPs of different elements like essential nutrients, beneficial nutrients and carbon-based nanoparticles are used for the remediation of metals contaminated soil and the production of metal free crops. Characterizing features of HNPs including particle size, surface area, reactivity, and solubility affect the efficacy of these HNPs in the contaminated environment. Hybrid nanoparticles have great potential to remove the HMs ions from soil solution and restrict their ingress into the root tissues. Furthermore, HNPs of essential nutrients not only compete with heavy metal uptake by plants but also fulfill the need of nutrients. This review provides a comprehensive overview of the challenges associated with application of HNPs in contaminated soils, environmental implications, their remediation ability, and factors affecting their dynamics in environmental matrices.

Chaga mushroom: a super-fungus with countless facets and untapped potential

Inonotus obliquus (Chaga mushroom) is an inexpensive fungus with a broad range of traditional and medicinal applications. These applications include therapy for breast, cervix, and skin cancers, as well as treating diabetes. However, its benefits are virtually untapped due to a limited understanding of its mycochemical composition and bioactivities. In this article, we explore the ethnobotany, mycochemistry, pharmacology, traditional therapeutic, cosmetic, and prospective agricultural uses. The review establishes that several secondary metabolites, such as steroids, terpenoids, and other compounds exist in chaga. Findings on its bioactivity have demonstrated its ability as an antioxidant, anti-inflammatory, antiviral, and antitumor agent. The study also demonstrates that Chaga powder has a long history of traditional use for medicinal purposes, pipe smoking rituals, and mystical future forecasts. The study further reveals that the applications of Chaga powder can be extended to industries such as pharmaceuticals, food, cosmetics, and agriculture. However numerous publications focused on the pharmaceutical benefits of Chaga with few publications on other applications. Overall, chaga is a promising natural resource with a wide range of potential applications and therefore the diverse array of therapeutic compounds makes it an attractive candidate for various applications such as plant biofertilizers and active ingredients in cosmetics and pharmaceutical products. Thus, further exploration of Chaga's potential benefits in agriculture and other industries could lead to exciting new developments and innovations.

Unraveling the effects of zinc sulfate nanoparticles and potassium fertilizers on quality of maize and associated health risks in Cd contaminated soils under different moisture regimes

This study investigated the interactive effects of zinc sulfate nanoparticles (ZnSO4 NPs) and potassium fertilizers (SOP and MOP) on growth and quality of maize (Zea mays L.) under different moisture regimes in cadmium contaminated soils. It seeks to identify how these two different sources of nutrients interact to improve the quality of maize grains and fodder production to ensure food safety and food security under abiotic stresses. The experiment was conducted in a greenhouse under two moisture regimes including M1 (non-limiting regime, 20-30 %) and M2 (water-limiting, 10-15 %) at Cd contamination of 20 mg kg-1. The results showed that ZnSO4 NPs combined with potassium fertilizers significantly increased the growth and proximate composition of maize in Cd contaminated soil. Moreover, applied amendments significantly alleviated the stress induced in maize by improving the growth. The greatest increase in maize growth and quality was observed when ZnSO4 NPs were applied in combination with SOP (K2SO4). The results also showed that the interactive effects of ZnSO4 NPs and potassium fertilizers significantly affected the Cd bioavailability in soil and concentration in plants. It was observed that MOP (KCl) enhanced the Cd bioavailability in soil due to presence of Cl anion. In addition, the application of ZnSO4 NPs combined with SOP fertilizer reduced the concentration of Cd in maize grain and shoot, and significantly reduced the probable health risks to humans and cattle. It suggested that this strategy could help to reduce Cd exposure through food consumption and therefore ensure food safety. Our findings suggest that ZnSO4 NPs and SOP can be used synergistically to improve maize crop production and development of agricultural practices in areas affected by Cd contamination. Moreover, by understanding the interactive effects of these two sources of nutrients, this research could help in the management of areas affected by heavy metals contamination. ENVIRONMENTAL IMPLICATION: The application of zinc and potassium fertilizers can increase the biomass of maize, minimize abiotic stresses, and improve the nutritional value of the crop in Cd contaminated soils; this is particularly true when zinc sulfate nanoparticles and sulfate of potash (K2SO4) are used in conjunction. This form of fertilizer management can lead to a greater, more sustainable yield of maize under contaminated soils, which could have a major impact on global food supply. Remediation coupled with agro-production (RCA) not only improves the effectiveness of the process but will also encourage farmers to take part in soil remediation by easy management.

Nano-stevia interaction: Past, present, and future

Nanotechnology has recently been emerged as a transformative technology that offers efficient and sustainable options for nano-bio interface. There has been a considerable interest in exploring the factors affecting elicitation mechanism and nanomaterials have been emerged as strong elicitors in medicinal plants. Stevia rebaudiana is well-known bio-sweetener and the presence of zero calorie, steviol glycosides (SGs) in the leaves of S. rebaudiana have made it a desirable crop to be cultivated on large scale to obtain its higher yield and maximal content of high quality natural sweeteners. Besides, phenolics, flavonoids, and antioxidants are abundant in stevia which contribute to its medicinal importance. Currently, scientists are trying to increase the market value of stevia by the enhancement in production of its bioactive compounds. As such, various in vitro and cell culture strategies have been adopted. In stevia agronanotechnology, nanoparticles behave as elicitors for the triggering of its secondary metabolites, specifically rebaudioside A. This review article discusses the importance of S. rebaudiana and SGs, conventional approaches that have failed to increase the desired yield and quality of stevia, modern approaches that are currently being applied to obtain utmost benefits of SGs, and future needs of advanced technologies for further exploitation of this wonder of nature.

Cannabis: a multifaceted plant with endless potentials

Cannabis sativa, also known as "hemp" or "weed," is a versatile plant with various uses in medicine, agriculture, food, and cosmetics. This review attempts to evaluate the available literature on the ecology, chemical composition, phytochemistry, pharmacology, traditional uses, industrial uses, and toxicology of Cannabis sativa. So far, 566 chemical compounds have been isolated from Cannabis, including 125 cannabinoids and 198 non-cannabinoids. The psychoactive and physiologically active part of the plant is a cannabinoid, mostly found in the flowers, but also present in smaller amounts in the leaves, stems, and seeds. Of all phytochemicals, terpenes form the largest composition in the plant. Pharmacological evidence reveals that the plants contain cannabinoids which exhibit potential as antioxidants, antibacterial agents, anticancer agents, and anti-inflammatory agents. Furthermore, the compounds in the plants have reported applications in the food and cosmetic industries. Significantly, Cannabis cultivation has a minimal negative impact on the environment in terms of cultivation. Most of the studies focused on the chemical make-up, phytochemistry, and pharmacological effects, but not much is known about the toxic effects. Overall, the Cannabis plant has enormous potential for biological and industrial uses, as well as traditional and other medicinal uses. However, further research is necessary to fully understand and explore the uses and beneficial properties of Cannabis sativa.

Phyto-oxylipin mediated plant immune response to colonization and infection in the soybean-Phytophthora sojae pathosystem

Introduction

Food security is a major challenge to sustainably supply food to meet the demands of the ever-growing global population. Crop loss due to pathogens is a major concern to overcoming this global food security challenge. Soybean root and stem rot caused by Phytophthora sojae results in approximately 20B $US crop loss annually. Phyto-oxylipins are metabolites biosynthesized in the plants by oxidative transformation of polyunsaturated fatty acids through an array of diverging metabolic pathways and play an important role in plant development and defense against pathogen colonization and infection. Lipid mediated plant immunity is a very attractive target for developing long term resistance in many plants' disease pathosystem. However, little is known about the phyto-oxylipin's role in the successful strategies used by tolerant soybean cultivar to mitigate Phytophthora sojae infection.

Methods

We used scanning electron microscopy to observe the alterations in root morphology and a targeted lipidomics approach using high resolution accurate mass tandem mass spectrometry to assess phyto-oxylipin anabolism at 48 h, 72 h and 96 h post infection.

Results and discussion

We observed the presence of biogenic crystals and reinforced epidermal walls in the tolerant cultivar suggesting a mechanism for disease tolerance when compared with susceptible cultivar. Similarly, the unequivocally unique biomarkers implicated in oxylipin mediated plant immunity [10(E),12(Z)-13S-hydroxy-9(Z),11(E),15(Z)-octadecatrienoic acid, (Z)-12,13-dihydroxyoctadec-9-enoic acid, (9Z,11E)-13-Oxo-9,11-octadecadienoic acid, 15(Z)-9-oxo-octadecatrienoic acid, 10(E),12(E)-9-hydroperoxyoctadeca-10,12-dienoic acid, 12-oxophytodienoic acid and (12Z,15Z)-9, 10-dihydroxyoctadeca-12,15-dienoic acid] generated from intact oxidized lipid precursors were upregulated in tolerant soybean cultivar while downregulated in infected susceptible cultivar relative to non-inoculated controls at 48 h, 72 h and 96 h post infection by Phytophthora sojae, suggesting that these molecules may be a critical component of the defense strategies used in tolerant cultivar against Phytophthora sojae infection. Interestingly, microbial originated oxylipins, 12S-hydroperoxy-5(Z),8(Z),10(E),14(Z)-eicosatetraenoic acid and (4Z,7Z,10Z,13Z)-15-[3-[(Z)-pent-2-enyl]oxiran-2-yl]pentadeca-4,7,10,13-tetraenoic acid were upregulated only in infected susceptible cultivar but downregulated in infected tolerant cultivar. These microbial originated oxylipins are capable of modulating plant immune response to enhance virulence. This study demonstrated novel evidence for phyto-oxylipin metabolism in soybean cultivars during pathogen colonization and infection using the Phytophthora sojae-soybean pathosystem. This evidence may have potential applications in further elucidation and resolution of the role of phyto-oxylipin anabolism in soybean tolerance to Phytophthora sojae colonization and infection.

Foliar application of mepiquat chloride and nitrogen improves yield and fiber quality traits of cotton (Gossypium hirsutum L.)

Cotton (Gossypium hirsutum L.) is one of the most important cash crops primarily grown for fiber. It is a perennial crop with indeterminate growth pattern. Nitrogen (N) is extremely important for vegetative growth as balanced N-nutrition improves photosynthesis, resulting in better vegetative growth. Excessive N-supply results in more vegetative growth, which increases the incidence of insect pest and diseases’ infestation, pollute surface and ground water, delays maturity and produces low crop yield with poor quality. The use of plant growth regulators (PGRs) is an emerging option to control excessive vegetative growth. The PGRs help in improving plant architecture, boll retention, boll opening, yield and quality by altering growth and physiological processes such as photosynthesis, assimilate partitioning and nutrients dynamic inside the plant body. Mepiquat chloride (1,1-dimethylpiperidinum chloride) is globally used PGR for canopy development and control of excessive vegetative growth in cotton. This study investigated the effect of mepiquat chloride (MC) and N application on yield and yield components of transgenic cotton variety ‘BT-FSH-326’. Two N rates (0, 198 kg ha-1) and five MC rates (0, 30,60, 90 and 120 g ha-1) were included in the study. Results revealed that MC and N application improved boll weight, number of bolls per plant, and seed cotton and lint yields. The highest seed cotton and lint yields (3595 kg ha-1 and 1701 kg ha-1, respectively) were observed under foliar application of 198 kg ha-1 N and 120 g ha-1 MC. Fiber length, fiber strength, micronaire and uniformity were significantly improved with foliar application of MC and N. In conclusion, foliar application of MC and N could be helpful in improving yield and fiber quality of cotton.

Microbial Consortium Associated with Crustacean Shells Composting

Soil microbes play an essential role in the biodegradation of crustacean shells, which is the process of sustainable bioconversion to chitin derivatives ultimately resulting in the promotion of plant growth properties. While a number of microorganisms with chitinolytic properties have been characterized, little is known about the microbial taxa that participate in this process either by active chitin degradation or by facilitation of this activity through nutritional cooperation and composting with the chitinolytic microorganisms. In this study, we evaluated the transformation of the soil microbiome triggered by close approximation to the green crab shell surface. Our data indicate that the microbial community associated with green crab shell matter undergoes significant specialized changes, which was reflected in a decreased fungal and bacterial Shannon diversity and evenness and in a dramatic alteration in the community composition. The relative abundance of several bacterial and fungal genera including bacteria Flavobacterium, Clostridium, Pseudomonas, and Sanguibacter and fungi Mortierella, Mycochlamys, and Talaromyces were increased with approximation to the shell surface. Association with the shell triggered significant changes in microbial cooperation that incorporate microorganisms that were previously reported to be involved in chitin degradation as well as ones with no reported chitinolytic activity. Our study indicates that the biodegradation of crab shells in soil incorporates a consortium of microorganisms that might provide a more efficient way for bioconversion.

Effects of Chilling Stress on Morphological, Physiological, and Biochemical Attributes of Silage Corn Genotypes during Seedling Establishment

Chilling stress is one of the major abiotic stresses which hinder seedling emergence and growth. Herein, we investigated the effects of chilling/low temperature stress on the morphological, physiological, and biochemical attributes of two silage corn genotypes during the seedling establishment phase. The experiment was conducted in a growth chamber, and silage corn seedlings of Yukon-R and A4177G-RIB were grown at optimum temperature up to V3 stage and then subjected to five temperature regimes (25 °C as control, 20 °C, 15 °C, 10 °C, and 5 °C) for 5 days. After the temperature treatment, the morphological, physiological, and biochemical parameters were recorded. Results indicated that temperatures of 15 °C and lower significantly affected seedling growth, photosynthesis system, reactive oxygen species (ROS) accumulation, and antioxidant enzyme activities. Changes in seedlings’ growth parameters were in the order of 25 °C > 20 °C > 15 °C > 10 °C > 5 °C, irrespective of genotypes. The chlorophyll content, photosynthetic rate, and maximal photochemical efficiency of PS-II (Fv/Fm) were drastically decreased under chilling conditions. Moreover, chilling stress induced accumulation of hydrogen peroxide (H2O2)and malonaldehyde (MDA) contents. Increased proline content and enzymatic antioxidants, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX), were found to alleviate oxidative damage under chilling stress. However, the genotype of Yukon-R exhibited better adaption to chilling stress than A4177G3-RIB. Yukon-R showed significantly higher proline content and enzymatic antioxidant activities than A4177G3-RIB under severe chilling conditions (temperature ≤ 10 °C). Similarly, Yukon-R expressed low temperature-induced ROS accumulation. Furthermore, the interaction effects were found between temperature treatment and genotype on the ROS accumulation, proline content and antioxidant enzyme activities. In summary, the present study indicated that Yukon-R has shown better adaptation and resilience against chilling temperature stress, and therefore could be considered a potential candidate genotype to be grown in the boreal climate.

Understanding the Adaptive Mechanisms of Plants to Enhance Phosphorus Use Efficiency on Podzolic Soils in Boreal Agroecosystems

Being a macronutrient, phosphorus (P) is the backbone to complete the growth cycle of plants. However, because of low mobility and high fixation, P becomes the least available nutrient in podzolic soils; hence, enhancing phosphorus use efficiency (PUE) can play an important role in different cropping systems/crop production practices to meet ever-increasing demands in food, fiber, and fuel. Additionally, the rapidly decreasing mineral phosphate rocks/stocks forced to explore alternative resources and methods to enhance PUE either through improved seed P reserves and their remobilization, P acquisition efficiency (PAE), or plant's internal P utilization efficiency (IPUE) or both for sustainable P management strategies. The objective of this review article is to explore and document important domains to enhance PUE in crop plants grown on Podzol in a boreal agroecosystem. We have discussed P availabilities in podzolic soils, root architecture and morphology, root exudates, phosphate transporters and their role in P uptake, different contributors to enhance PAE and IPUE, and strategies to improve plant PUE in crops grown on podzolic soils deficient in P and acidic in nature.

Data set showing the development of a hyperspectral imaging technique using LA-ICP-MS to determine the spatial distribution of nutrients in soil cores

This data in brief article represents the data set associated with a research article published in Geoderma [1]. The data set represents figures showing the spatial distribution of selected macro and micronutrients, and their quantification in different crop or nutrient management systems practiced in the boreal ecosystem. Spatial distribution of nutrients was measured by laser ablation inductively coupled plasma mass spectrometry (LA‒ICP‒MS), using the new techniques we developed to visualize nutrient distribution in intact soil cores representative of the root rhizosphere. This data article supports the findings published in the main article [1]. This work also demonstrates that LA-ICP-MS is a valuable technique to image the spatial distribution of macro and micronutrients in intact soil cores as affected by different crop management practices.

Potential of developing podzolic soil-based potting media from wood ash, paper sludge and biochar

BACKGROUND AND OBJECTIVES

Organic waste management in environmentally sustainable way is important not only to reduce the negative impacts on ecosystems but also valorizing the waste resources. Herein we evaluated the potential of wood ash (WA) and paper sludge (PS) wastes from a pulp and paper mill as potting media and their effects on the physicochemical properties of podzolic soil.

METHODS

WA, PS and biochar (BC) was mixed in different combinations with a sandy loam podzolic soil. Potting media treatments included: T1-soil (negative control); T2-Promix^TM (positive control); T3-50%soil+50%WA; T4-75%soil+25%WA; T5-50%soil+50%PS; T6-75%soil+25%PS; T7-75%soil+25%BC; T8-25%soil+50%WA+25%BC; T9-50%soil+25%WA+25%BC; T10-25%soil+50%PS+25%BC; T11-50%soil+25%PS+25%BC, T12- 25%soil+25%WA+25%PS+25%BC and replicated three times.

RESULTS

Potting media treatments expressed significant (p < 0.00) effects on pH, bulk density, total porosity, field capacity, plant available water (PAW) and water retention curves. Potting media amended with WA showed high pH range (8-12) while PS amendments exhibited pH in range where most plant nutrients are available (6.5-7.5). Results depicted significantly lower bulk density, and increased total porosity and water holding capacity of potting media amended with WA and PS. BC addition further enhanced the water retention properties compared to combinations without BC. T6, T10 and T11 produced higher amounts of PAW with desired pH compared to T1 and T2.

CONCLUSION

WA, PS and BC showed high potential for developing podzolic soil-based potting media, but their effects on plant growth and elemental uptake need to be investigated.

Exogenous application of silicon improves the performance of wheat under terminal heat stress by triggering physio-biochemical mechanisms

Due to climate change, temperature in late February and early March raised up which cause heat stress at reproductive stage (terminal growth phase of wheat crop) which has become the major causative factor towards low wheat production in arid and semiarid regions. Therefore; strategies need to be adopted for improving terminal heat stress tolerance in wheat. In this study, we assessed whether foliar application of silicon (Si) (2 and 4 mM) at terminal growth phase i.e. heading stage of wheat imposed to heat stress (37 ± 2 °C) under polythene tunnel could improve the performance of wheat. Results of the study revealed that heat stress significantly reduced the photosynthetic pigments (chlorophyll a, b and a + b and carotenoids) leading to a lower grain yield. However, a 4 mM Si application (foliar applied) at heading stage prominently increased the chlorophyll a, b and a + b and carotenoids of flag leaf by improving the activities of enzymatic antioxidants (catalase, peroxidase and superoxide dismutase) and osmoprotectants (soluble sugar protein and proline) under terminal heat stress. Improvements in the performance of wheat (chlorophyll contents, carotenoids, soluble sugar and proteins and proline and yield) with foliar application of Si were also observed under control conditions. Correlation analysis revealed strong association (r > 0.90) of chlorophyll contents and carotenoids with grain and biological yield. Negative correlation (-0.81 < r > -0.63) of physio-biochemical components (antioxidants, proline, soluble sugars and proteins) with yield revealed that under heat stress these components produced in more quantities to alleviate the effects of heat, and Si application also improved these physio biochemical components. In crux, foliar application of Si alleviates the losses in the performance of wheat caused by terminal heat stress by improving the antioxidant mechanism and production of osmoprotectants.

Effects of pH and Temperature on Water under Pressurized Conditions in the Extraction of Nutraceuticals from Chaga (Inonotus obliquus) Mushroom

Currently, there is increased interest in finding appropriate food-grade green extraction systems capable of extracting these bioactive compounds from dietary mushrooms for applications in various food, pharmacological, or nutraceutical formulations. Herein, we evaluated a modified Swiss water process (SWP) method using alkaline and acidic pH at low and high temperature under pressurized conditions as a suitable green food grade solvent to obtained extracts enriched with myco-nutrients (dietary phenolics, total antioxidants (TAA), vitamins, and minerals) from Chaga. Ultra-high performance liquid chromatography coupled to high resolution accurate mass tandem mass spectrometry (UHPLC-HRAMS-MS/MS) was used to assess the phenolic compounds and vitamin levels in the extracts, while inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the mineral contents. Over 20 phenolic compounds were quantitatively evaluated in the extracts and the highest total phenolic content (TPC) and total antioxidant activity (TAA) was observed at pH 11.5 at 100 °C. The most abundant phenolic compounds present in Chaga extracts included phenolic acids such as protocatechuic acid 4-glucoside (0.7–1.08 µg/mL), syringic acid (0.62–1.18 µg/mL), and myricetin (0.68–1.3 µg/mL). Vitamins are being reported for the first time in Chaga. Not only, a strong correlation was found for TPC with TAA (r-0.8, <0.0001), but also, with individual phenolics (i.e., Salicylic acid), lipophilic antioxidant activity (LAA), and total antioxidant minerals (TAM). pH 2.5 at 100 °C treatment shows superior effects in extracting the B vitamins whereas pH 2.5 at 60 and 100 °C treatments were outstanding for extraction of total fat-soluble vitamins. Vitamin E content was the highest for the fat-soluble vitamins in the Chaga extract under acidic pH (2.5) and high temp. (100 °C) and ranges between 50 to 175 µg/100 g Chaga. Antioxidant minerals ranged from 85.94 µg/g (pH7 at 100 °C) to 113.86 µg/g DW (pH2.5 at 100 °C). High temperature 100 °C and a pH of 2.5 or 9.5. The treatment of pH 11.5 at 100 °C was the most useful for recovering phenolics and antioxidants from Chaga including several phenolic compounds reported for the first time in Chaga. SWP is being proposed herein for the first time as a novel, green food-grade solvent system for the extraction of myco-nutrients from Chaga and have potential applications as a suitable approach to extract nutrients from other matrices. Chaga extracts enriched with bioactive myconutrients and antioxidants may be suitable for further use or applications in the food and nutraceutical industries.

Corn-Soybean Intercropping Improved the Nutritional Quality of Forage Cultivated on Podzols in Boreal Climate

Intercropping systems could be a potential source of nutrient-rich forage production in cool climates on podzolic soils common in boreal ecosystems. In this study, we evaluated the effects of corn-soybean intercropping (IC) on the nutritional quality of forage. Two silage corn varieties were cultivated as monocropping (MC) or were intercropped with three forage soybean varieties using a randomized complete block design. IC significantly increased the crude protein (22%) and decreased the acid detergent (14%) and neutral detergent (6%) fibers. Forage net energy, total digestible nutrients, ash, dry matter intake, digestible dry matter and relative feed value were also significantly increased (p ≤ 0.05) in the IC treatments compared to corn MC. The macro and micro nutrients were higher in IC than corn MC. Intercropping increased the omega 3 fatty acid (FA) contents (67%) compared to corn MC. IC also increased the active microbial community in the plant root zone, which may contribute to the improvement in forage nutritional quality because the active soil microbial community composition showed significant correlations with soluble sugars, soluble proteins and potassium contents of the forage. These results demonstrate that corn-soybean IC could be a suitable cropping system to increase the nutritional quality of forage cultivated on podzols in boreal climates. The resultant forage has the potential to be a source of high-value animal feed for livestock production in cool climate regions of the world.

Recent advances in bio-chemical, molecular and physiological aspects of membrane lipid derivatives in plant pathology

Plant pathogens pose a significant threat to the food industry and food security accounting for 10-40% crop losses annually on a global scale. Economic losses from plant diseases are estimated at $300B for major food crops and are associated with reduced food availability and accessibility and also high food costs. Although strategies exist to reduce the impact of diseases in plants, many of these introduce harmful chemicals to our food chain. Therefore, it is important to understand and utilize plants' immune systems to control plant pathogens to enable more sustainable agriculture. Lipids are core components of cell membranes and as such are part of the first line of defense against pathogen attack. Recent developments in omics technologies have advanced our understanding of how plant membrane lipid biosynthesis, remodelling and/or signalling modulate plant responses to infection. Currently, there is limited information available in the scientific literature concerning lipid signalling targets and their biochemical and physiological consequences in response to plant pathogens. This review focusses on the functions of membrane lipid derivatives and their involvement in plant responses to pathogens as biotic stressors. We describe major plant defense systems including systemic-acquired resistance, basal resistance, hypersensitivity and the gene-for-gene concept in this context.

Root membrane lipids as potential biomarkers to discriminate silage-corn genotypes cultivated on podzolic soils in boreal climate

Root membrane lipids are important biomolecules determining plant's ability to adapt to different growing environmental or climatic conditions. Herein, we demonstrate the potential use of root membrane lipids as biomarkers to discriminate silage-corn genotypes based on herbicide and insect/pest resistance genetic traits when cultivated on podzolic soils under short growing and moderately warm summer season in boreal climate. Lipids in root membranes of field grown silage-corn genotypes were previously quantified at crop maturity by ultra-high-performance liquid chromatography-hydrophilic interaction chromatography-heated electrospray ionization mass spectrometry. The lipid identified and quantified in silage-corn roots were phospholipids, glycolipids and sphingolipids. Following hierarchical cluster analysis, three groups of membrane lipids were observed to be very effective in segregating the five silage-corn genotypes. The first group consisted of hexosylceramide (HexCer), phosphatidylcholine (PC) and phosphatidylinositol (PI). The second group consisted of lysophosphatidic acid (LPA16:0) and lysophosphatidylcholine (LPC16:0), while the third group consisted of 37 molecular species from observed lipids (phospholipids, glycolipids, sphingolipids). Partial least squares-discriminant analysis (PLS-DA) based on 37 membrane lipid species, as well as principal component analysis using the variables important in projection derived from the PLS-DA segregated the five silage-corn genotypes into three groups according to their pesticide/herbicide resistant traits. This study is second to none using root lipidomics in discriminating different silage-corn genotypes based on their herbicide and insect/pest resistance genetic traits for cultivation in boreal climates. The segregated genotypes possess three different genetic traits for herbicide and insect/pest resistance including VT Double Pro (VT2P), VT Triple Pro Roundup Ready (VT3P/RR) and Roundup Ready-2 corn (RR2). These findings demonstrate that root membrane lipids could serve as appropriate chemical biosignatures to identify silage-corn genotypes based on herbicide and insect/pest resistance genetic traits suitable for cultivation in boreal climates.

Biochar amendment mitigates greenhouse gases emission and global warming potential in dairy manure based silage corn in boreal climate

About 11% of the global anthropogenic greenhouse gases (GHGs) emissions result from agricultural practices. Dairy manure (DM) application to soil is regarded as a best management practice due to C sequestration and improvement of soil physiochemical properties. However, GHGs emissions from the soil following the DM application could offset its advantages. Biochar (BC) is known to affect N transformation and GHGs emissions from soil. There had been considerably less focus on the BC amendment and its effects on GHGs emissions following DM application under field conditions. The objectives of this study were; i) to determine the temporal patterns and cumulative GHGs fluxes following DM and inorganic nitrogen (IN) application and, ii) to investigate BC amendment impact on DMY, GWP, direct N₂O emission factor (EF_d) and the response of CH₄ emissions (RC) in DM based silage corn. To achieve these objectives a two-year field experiment was conducted with these treatments: 1) DM with high N conc. (DM₁: 0.37% N); 2) DM with low N conc. (DM₂: 0.13% N); 3) IN; 4) DM₁+BC; 5) DM₂+BC; 6) IN + BC; and 7) Control (N₀); and were laid out in randomized complete block design with four replications. BC amendment to DM₁, DM₂ and IN significantly reduced cumulative CO₂ emission by 16, 25.5 and 26.5%, CH₄ emission by 184, 200 and 293% and N₂O emission by 95, 86 and 93% respectively. It also reduced area-scaled and yield-scaled GWP, EF_d, RC and enhanced DMY. Thus, BC application showed great potential to offset the negative effects of DM application i.e GHGs emissions from the silage corn cropping system. Further research is needed to evaluate soil organic carbon and nitrogen dynamics (substrates for GHG emissions) after DM and BC application on various soil types and cropping systems under field conditions.

Carbon Nanotubes Improved the Germination and Vigor of Plant Species from Peatland Ecosystem Via Remodeling the Membrane Lipidome

Application of the nanopriming technique to alleviate seed dormancy has shown promising results in various agricultural crop species. However, there is a dearth of knowledge regarding its potential use in native peatland boreal forest species to alleviate seed dormancy and improve their propagation or vigor for forest reclamation activities. Herein, we demonstrate the use of nanopriming with carbon nanotubes (CNT) to alleviate seed dormancy, improved seed germination, and seedling vigor in two boreal peatland species. Bog birch (Betula pumila L.) and Labrador tea (Rhododendron groenlandicum L.) seeds with embryo or seed coat dormancy were nanoprimed with either 20 or 40 µg/mL CNT, cold stratified at 2–4 °C for 15 days, and allowed to germinate at room temperature. The emerged seedlings’ lipidome was assessed to decipher the role of lipid metabolism in alleviating seed dormancy. We observed significant (p < 0.05) improvement in seedling germination and seedling vigor in seeds primed with multiwalled carbon nanotubes functionalized with carboxylic acids. Phosphatidylcholine (PC 18:1/18:3), phosphatidylglycerol (PG 16:1/18:3), and lysophosphatidylcholine (LPC 18:3) molecular species (C18:3 enriched) were observed to be highly correlated with the increased seed germination percentages and the enhanced seedling vigor. Mechanistically, it appears that carbon nanoprimed seeds following stratification are effective in mediating seed dormancy by remodeling the seed membrane lipids (C18:3 enriched PC, PG, and LPC) in both peatland boreal forest species. The study results demonstrate that nanopriming may provide a solution to resolve seed dormancy issues by enhancing seed germination, propagation, and seedling vigor in non-resource boreal forest species ideally suited for forest reclamation following anthropogenic disturbances.

Canola produced under boreal climatic conditions in Newfoundland and Labrador have a unique lipid composition and expeller press extraction retained the composition for commercial use

The average fatty acid (FA) composition of canola oil is made up of 62% oleic acid (C18:1n9), 19% linoleic acid (C18:2n6), 9% linolenic acid (C18:3n3) and 7% saturated FA (SFA). We investigated whether boreal climate (7.5-17.2 °C) favorably altered the FA composition of canola. Results indicate that canola cultivated in boreal climatic conditions had approximately twice the levels of omega-3 FA (17-20%) compared to canola from other growing areas (9%). The presence of monoacetyldiacylglycerol (MAcDG), a unique class of triglyceride, is reported for the first time in canola cultivated in a boreal climate, and has the potential to reduce the risk of obesity and other health related diseases. We further demonstrated that a non-solvent based extraction method retained the novel lipid composition without reducing the quality of oil being produced. Our results contribute significantly to the understanding of lipid accumulation in the world's second most important oil crop when cultivated in a boreal or northern climate.

Carbon Nanoparticles Functionalized with Carboxylic Acid Improved the Germination and Seedling Vigor in Upland Boreal Forest Species

Nanopriming has been shown to significantly improve seed germination and seedling vigor in several agricultural crops. However, this approach has not been applied to native upland boreal forest species with complex seed dormancy to improve propagation. Herein, we demonstrate the effectiveness of carbon nanoparticles functionalized with carboxylic acids in resolving seed dormancy and improved the propagation of two native upland boreal forest species. Seed priming with carbon nanoparticles functionalized with carboxylic acids followed by stratification were observed to be the most effective in improving germination to 90% in green alder (Alnus viridis L.) compared to 60% in the control. Conversely, a combination of carbon nanoparticles (CNPs), especially multiwall carbon nanoparticles functionalized with carboxylic acid (MWCNT–COOH), cold stratification, mechanical scarification and hormonal priming (gibberellic acid) was effective for buffaloberry seeds (Shepherdia canadensis L.). Both concentrations (20 µg and 40 µg) of MWCNT–COOH had a higher percent germination (90%) compared to all other treatments. Furthermore, we observed the improvement in germination, seedling vigor and resolution of both embryo and seed coat dormancy in upland boreal forest species appears to be associated with the remodeling of C18:3 enriched fatty acids in the following seed membrane lipid molecular species: PC18:1/18:3, PG16:1/18:3, PE18:3/18:2, and digalactosyldiacylglycerol (DGDG18:3/18:3). These findings suggest that nanopriming may be a useful approach to resolve seed dormancy issues and improve the seed germination in non-resource upland boreal forest species ideally suited for forest reclamation following resource mining.

Potential role of root membrane phosphatidic acid in superior agronomic performance of silage-corn cultivated in cool climate cropping systems

The literature is replete with information describing the composition of the root lipidome in several plant species grown under various environmental conditions. However, it is unknown to what extent the root membrane lipidome vary between silage-corn genotypes, and how such variation could influence agronomic performances during field cultivation in cool climate. To address this issue, the root membrane lipidome and agronomic performance were assessed for five silage-corn genotypes (Fusion-RR, Yukon-R, A4177G3-RIB, DKC23-17RIB, DKC26-28RIB) cultivated under cool climatic conditions. Leaf area, plant height and biomass production were used as agronomic performance indicators. Varieties DKC26-28RIB and Yukon-R expressed significantly higher leaf area, plant height and biomass production compared to the other genotypes. A strong positive Spearman rank-order correlation (P = 0.001) was observed between biomass production and root phosphatidic acid (PA). The high correlation observed between PA and agronomic performance indicates PA could potentially be used as biomarker to assist in the selection of silage-corn genotypes with superior agronomic performance ideally suited for field cultivations in cool climatic conditions.

The potential of corn-soybean intercropping to improve the soil health status and biomass production in cool climate boreal ecosystems

Intercropping (IC) is a promising approach used to improve soil health and sustainable crop production. However, it is unknown whether IC improve the soil health status and biomass productivity of crops cultivated in podzols under cool climate in boreal ecosystems. Two silage corn and three forage soybean genotypes were cultivated either as inter or monocrop (MC) treatments in a randomized complete block design. IC resulted in 28% increase in total forage production (FP). A reduction in rhizosphere soil pH (RS-pH) was observed in the IC treatments. Conversely, the rhizosphere soil acid phosphatase (RS-APase) activity was significantly higher (26-46%) in the IC treatments and occurred concomitant with a significant increase in available phosphorus (RS-Pavailable) (26-74%) in the rhizosphere. Furthermore, IC enhanced the active microbial composition and strong positive correlations were observed between RS-Pavailable, RS-APase, microbial biomass and FP; while RS-pH was negatively correlated with FP, RS-APase and RS-Pavailable. These findings suggested silage corn intercropped with forage soybean could be a viable approach to enhance FP through improved active microbial community structure, RS-APase activity and RS-Pavailable when cultivated on podzols in cool climate boreal ecosystem.

The soybean root membrane lipids and forage quality data in response to field cultivation on agricultural podzols in boreal climates

The objective of this data in brief article is to represent the associated data set regarding our published paper in Plant Science Nadeem et al., 2019. Data set represent soil acid phosphatase activity, association of individual molecular species of four major lipid classes with soybean forage quality indices when cultivated in boreal podzolic soils under cool climatic conditions. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA) and acylated glucosyl betasitosterol ester (AGIcSiE) molecular species grouped the soybean forage quality indices in different quadrants on principal component analyses. Furthermore, the total lipid profile and correlation of major lipid species with forage quality indices are included in this data in brief article. This data set support the main findings described in Nadeem et al., 2019.

Adaptation strategies of forage soybeans cultivated on acidic soils under cool climate to produce high quality forage

Boreal soils tend to be podzols characterized by acidic pH, which can further limit forage crop growth and production. It is unclear, how forage soybeans adopt to produce forage with high nutritional quality when cultivated on podzols in boreal climate. To answer this question, we cultivated forage soybeans on agricultural podzols at 3 farm sites with varied soil pH (6.8, 6.0 or 5.1), and assessed the root membrane lipidome remodeling response to such climatic conditions. Contrary to our expectations, significantly lower biomass was observed at pH 6.8 compared to 6.0 and 5.1. However, surprisingly the plants produced similar forage quality at 6.8 and 5.1 pH. Three major lipid classes including phospholipids, glycolipids and phytosterols were observed in roots irrespective of soil pH. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA), and acylated glucosyl betasitosterol ester (AGlcSiE) accounted for 95% of the root lipidome, and expressed significant changes in response to cultivation across the three soil pH levels. These lipids were also observed to have strong correlations with forage production, and forage quality. Therefore, soybean genotypes with higher abilities to remodel PC, PE, PA, and AGlcSiE could be better suited for producing higher quality forage in acid podzolic soils characteristics of boreal ecosystems.

The association of lipophilic phospholipids with native bovine casein micelles in skim milk: Effect of lactation stage and casein micelle size

A known biological role of casein micelles is to transport calcium from mother to young and provide amino acids for growth and development. Previous reports demonstrated that modified casein micelles can be used to transport and deliver hydrophobic probes. In this study, the distribution of lipid-soluble phospholipids, including sphingomyelins (SM) and phosphatidylcholines (PC), was quantified in whole raw milk, skim raw milk, and casein micelles of various sizes during early, mid, and late lactation stages. Low-pressure size exclusion chromatography was used to separate casein micelles by size, followed by hydrophobic extraction and liquid chromatography-mass spectrometry for the quantification of PC and SM. Results showed that the SM d18:1/23:0, d18:1/22:0, d18:1/16:0, d16:1/22:0, d16:1/23:0, and d18:1/24:0 and the PC 16:0/18:1, 18:0/18:2, and 16:0/16:0 were dominating candidates appearing in maximum concentration in whole raw milk obtained from late lactation, with 21 to 50% of total SM and 16 to 35% of total PC appearing in skim milk. Of the total SM and PC found in skim milk, 35 to 46% of SM and 22 to 29% of PC were associated with the casein micelle fraction. The highest concentrations of SM d18:1/22:0 (341 ± 17 µg/g of casein protein) and PC 16:0/18:1 (180 ± 20 µg/g of casein protein) were found to be associated with the largest casein micelles (diameter = 149 nm) isolated in milk from late lactation, followed by a decrease in concentration as the casein micelle size decreased.

The binding of orally dosed hydrophobic active pharmaceutical ingredients to casein micelles in milk

Casein proteins (α_S1-, α_S2-, β- and κ-casein) account for 80% of the total protein content in bovine milk and form casein micelles (average diameter = 130 nm, approximately 10¹⁵ micelles/mL). The affinity of native casein micelles with the 3 hydrophobic active pharmaceutical ingredients (API), meloxicam [351.4 g/mol; log P = 3.43; acid dissociation constant (pK_a) = 4.08], flunixin (296.2 g/mol; log P = 4.1; pK_a = 5.82), and thiabendazole (201.2 g/mol; log P = 2.92; pK_a = 4.64), was evaluated in bovine milk collected from dosed Holstein cows. Native casein micelles were separated from raw bovine milk by mild techniques such as ultracentrifugation, diafiltration, isoelectric point precipitation (pH 4.6), and size exclusion chromatography. Acetonitrile extraction of hydrophobic API was then done, followed by quantification using HPLC-UV. For the API or metabolites meloxicam, 5-hyroxy flunixin and 5-hydroxy thiabendazole, 31 ± 3.90, 31 ± 1.3, and 28 ± 0.5% of the content in milk was associated with casein micelles, respectively. Less than ∼5.0% of the recovered hydrophobic API were found in the milk fat fraction, and the remaining ∼65% were associated with the whey/serum fraction. A separate in vitro study showed that 66 ± 6.4% of meloxicam, 29 ± 0.58% of flunixin, 34 ± 0.21% of the metabolite 5-hyroxy flunixin, 50 ± 4.5% of thiabendazole, and 33 ± 3.8% of metabolite 5-hydroxy thiabendazole was found partitioned into casein micelles. Our study supports the hypothesis that casein micelles are native carriers for hydrophobic compounds in bovine milk.

The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk

The agreed biological function of the casein micelles in milk is to carry minerals (calcium, magnesium, and phosphorus) from mother to young along with amino acids for growth and development. Recently, native and modified casein micelles were used as encapsulating and delivery agents for various hydrophobic low-molecular-weight probes. The ability of modified casein micelles to bind certain probes may derive from the binding affinity of native casein micelles. Hence, a study with milk from single cows was conducted to further elucidate the association of hydrophobic molecules into native casein micelles and further understand their biological function. Hydrophobic and hydrophilic extraction followed by ultraperformance liquid chromatography-high resolution mass spectrometry analysis were performed over protein fractions obtained from size exclusion fractionation of raw skim milk. Hydrophobic compounds, including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin, showed strong association exclusively to casein micelles as compared with whey proteins, whereas hydrophilic compounds did not display any preference for their association among milk proteins. Further analysis using liquid chromatography-tandem mass spectrometry detected 42 compounds associated solely with the casein-micelles fraction. Mass fragments in tandem mass spectrometry identified 4 of these compounds as phosphatidylcholine with fatty acid composition of 16:0/18:1, 14:0/16:0, 16:0/16:0, and 18:1/18:0. These results support that transporting low-molecular-weight hydrophobic molecules is also a biological function of the casein micelles in milk.

Second messengers in platelet aggregation evoked by serotonin and A23187, a calcium ionophore

We investigated the combined effect of 5-hydroxytryptamine (5-HT, serotonin) and calcium ionophore (A23187) on human platelet aggregation. Aggregation, monitored at 37 degrees C using a Dual-channel Lumi-aggregometer, was recorded for 5 min after challenge by a change in light transmission as a function of time. 5-HT (2-200 microM) alone did not cause platelet aggregation, but markedly potentiated A23187 (low dose) induced aggregation. Inhibitory concentration (IC50) values for a number of compounds were calculated as means +/- SEM from dose-response determinations. Synergism between 5-HT (2-5 microM) and A23187 (0.5-2 microM) was inhibited by 5-HT receptor blockers, methysergide (IC50 = 18 microM) and cyproheptadine (IC50 = 20 microM), and calcium channel blockers (verapamil and diltiazem, IC50 = 20 microM and 40 microM respectively). Interpretation of the effects of these blockers is complicated by their lack of specificity. Similarly, U73122, an inhibitor of phospholipase C (PLC), blocked the synergistic effect at an IC50 value of 9.2 microM. Wortmannin, a phosphatidylinositide 3-kinase (PI 3-K) inhibitor, also blocked the response (IC50 = 2.6 microM). However, neither genistein, a tyrosine-specific protein kinase inhibitor, nor chelerythrine, a protein kinase C inhibitor, affected aggregation at concentrations up to 10 microM. We conclude that the synergistic interaction between 5-HT and ionophore may be mediated by activation of PLC/Ca2+ and PI 3-kinase signalling pathways, but definitive proof will require other enzyme inhibitors with greater specificity.

Pattern of thyroid lesions and role of fine needle aspiration cytology (FNA) in the management of thyroid enlargement: a retrospective study from a teaching hospital in Riyadh

The study aims to determine the cytological pattern of thyroid lesions, in addition to the utility and accuracy of fine needle aspiration (FNA) cytology as an initial diagnostic method in the investigation of these lesions among Saudi patients. Four hundred and seventy-nine (479) FNAs were performed on patients presenting with diffuse or nodular thyroid enlargement to the endocrinology clinic at King Khalid University Hospital in Riyadh during the period September 1993 to September 1996. The results of the FNA and the 125 histological diagnoses obtained from the subsequent partial and subtotal thyroidectomies were retrospectively and independently reviewed and compared by two cytopathologists. The results of the FNA cytological diagnosis showed that 372 patients (77.7%) had benign lesions, 24 (5%)) had lesions which were suspected of malignancy, 25 (5.2%) had malignant neoplasms, and 58 (12.1%) had FNAs which were inadequate for cytological assessment. Colloid and adenomatous nodules were the most common benign lesions reported (47.8%). Papillary carcinoma was the most common malignant neoplasm (4.2%). Despite the relatively limited number of patients who underwent surgery, cytohistopathology combined with statistical analysis of the results showed that our FNA accuracy rate is in the region of 94.4% with a sensitivity of 78% and a specificity of 100%. In addition, the negative predictive value (NPV) and the positive predictive value (PPV) of FNA thyroid cytology were 93% and 100% respectively. Our findings indicate that FNA cytology can be used effectively in the evaluation of both nodular and diffuse thyroid lesions whilst cytopathologist should be aware of the potential diagnostic pitfalls and the limitations of the procedure in the diagnosis of follicular, cystic, and small neoplasms, the positive identification of thyroiditis and most cases of neoplasia by itself provides justification for FNA.

The value of immediate cytologic evaluation for needle aspiration lung biopsy

RATIONALE AND OBJECTIVES

The authors evaluate the role of immediate cytologic evaluation (ICE) with fine-needle aspiration biopsy (FNAB) for lung lesions at highest risk for pneumothorax.

METHODS

A prospective randomized study was conducted of 80 patients with lung lesions surrounded by aerated parenchyma undergoing FNAB with and without ICE (47 and 33 patients, respectively). An analysis of needle passes, procedure time, complications, specimen adequacy, diagnostic yield, and accuracy of procedure was made.

RESULTS

There was an increased number of needle passes with ICE (> or = three passes: 23% [11 biopsies] versus 3% [1 biopsy]; P = 0.01). Fluoroscopic procedures took longer with ICE (median time: 15 versus 9 minutes; P = 0.002) with no difference in complication rates. Specimen adequacy was similar (74% and 64%) and the procedure was diagnostic in 79% (37 biopsies) with ICE and in 70% (33 biopsies) without ICE. There were no significant differences in the sensitivity, specificity, or accuracy of the biopsy.

CONCLUSIONS

Immediate cytologic evaluation improved results marginally with increased procedure time and needle passes. Immediate cytologic evaluation may be most useful for lesions at lowest risk of complications to assure that a second procedure is not required.

Ethanol-induced aspartate and taurine release from primary astrocyte cultures

Exposure of primary astrocyte cultures to isosmotic ethanol from 10-100 mM led to both swelling of the cells and release of [3H]taurine and D-[3H]aspartate. Exposure to hyperosmotic ethanol, in the same concentration range, caused neither swelling nor release. Release was inhibited by the anion transport blocker L-644,711, already shown to inhibit amino acid release evoked by hypoosmotic or high-potassium medium, conditions that also cause astrocytic swelling. Ethanol-induced release generally showed a decline in response to successive exposures to ethanol, and release was not dependent on extracellular calcium. Thus, the characteristics of swelling-induced release of amino acids by isosmotic ethanol seem to correspond to those of swelling-induced release from astrocytes due to exposure to hypotonic or high-K+ media. We discuss whether such effects may contribute to CNS damage after head injury and stroke.

Effects of conjugated estrogen on the calcitriol response to parathyroid hormone in postmenopausal women

We evaluated the effects of estrogen on the calcitriol response to the active peptide, human PTH(1-34), in postmenopausal women. Fifteen women were studied before and again after at least 1 month of treatment with conjugated equine estrogens, 1.25 mg/day. Six women received two series of four graded peptide infusions, each with the sequence 200, 400, 800, and 1600 USP U hPTH(1-34). Nine women received only one dose of peptide, either 200 or 800 U, before and while taking estrogen. Baseline values and the incremental and percent changes in circulating calcitriol 24 h after the 20-min infusions were evaluated. Estrogen treatment resulted in significant reductions in blood levels of calcium (2.26 +/- 0.03 mmol/L vs. 2.16 +/- 0.02, P less than 0.05) and phosphorus (1.23 +/- .05 mmol/L vs. 1.14 +/- 0.03, P less than 0.005), a rise in serum calcitriol concentrations (42.2 +/- 3.9 pg/mL vs. 28.6 +/- 3.1, P less than 0.005), and no change in circulating PTH. The rise in calcitriol after 200 U hPTH(1-34) was significantly greater on estrogen (17.6 +/- 2.0 pg/mL vs. 9.5 +/- 1.8, P less than 0.01), but estrogen did not alter incremental responses to larger doses. When results were normalized for differences in baseline values, the estrogen-related change in response to 200 U was no longer significant. hPTH(1-34) acutely increased urinary clearance of cAMP and phosphorus, but estrogen did not affect this response. We conclude that exogenous estrogen does not increase renal sensitivity to PTH in postmenopausal women.

Effects of aluminum hydroxide on the parathyroid-vitamin D axis of postmenopausal women

In previous studies we proposed that estrogen increases circulating calcitriol in postmenopausal women by reducing plasma phosphorus concentrations. For this model to be plausible, a reduction in plasma phosphorus must be itself be sufficient to increase circulating calcitriol in elderly women. To assess this question we studied the effects of Al(OH)3 on daylong circulating levels of phosphorus, calcium, PTH, and calcitriol in 14 postmenopausal women. Subjects were studied on two 7-day periods of dietary control, in which calculated intakes for phosphorus, calcium, and sodium were 950, 800, and 3000 mg/day, respectively. During one randomly assigned period, subjects were given Al(OH)3 with each meal. Al(OH)3 significantly lowered daylong plasma phosphorus concentrations by 17% (0.95 +/- 0.02 mmol/L vs. 1.15 +/- 0.02, P less than 0.0005) (2.94 +/- 0.06 mg/dL vs. 3.57 +/- 0.07), and this was associated with a 38% rise in circulating calcitriol from 61.8 +/- 10.3 pmol/L to 85.2 +/- 10.1 pmol/L (25.7 +/- 4.3 pg/ml to 35.5 +/- 4.2 pg/ml) (P less than 0.0001). The rise in calcitriol correlated significantly with the reduction in phosphorus (r = 0.51, P = 0.03). Al(OH)3 did not significantly alter average daily circulating total calcium (2.32 +/- 0.008 vs. 2.32 +/- 0.005 mmol/L) (9.31 +/- 0.03 vs. 9.29 +/- 0.02 mg/dL), ionized calcium (1.19 +/- 0.003 vs. 1.19 +/- .004 mmol/L), or intact PTH (24.6 +/- 0.6 vs. 24.2 +/- 0.8 ng/L). Moreover, neither the renal phosphorus reabsorption maximum (TmP/GFR), baseline excretion of cAMP, nor the phosphaturic, cAMP, or calcitriol responses to infused hPTH(1-34) were altered by Al(OH)3. We conclude that Al(OH)3 treatment of older women lowers plasma phosphorus concentrations by restricting intestinal phosphorus absorption, and that older women retain the capacity to increase calcitriol levels in response to phosphorus restriction.

Lipid vehicles for intestinal lymphatic drug absorption

The lipoprotein fractions in mesenteric lymph were monitored following intraduodenal administration of arachis oil and oleic, linoleic and linolenic fatty acids to rats. An increase in the chylomicron fraction, but not the VLDL or LDL fraction, was observed with each lipid. The greater the degree of unsaturation of the fatty acid, the more rapid the onset of chylomicron synthesis. The administration of linoleic acid and arachis oil produced the highest concentration of chylomicrons in the lymph. These results reflect differences in the rate of absorption and biochemical metabolism of the lipids and have implications for the selection of vehicles for the delivery of drugs by the lymphatic route.