Tissue Calcium Content Research Articles

Placental Element Content Assessed via Synchrotron-Based X-ray Fluorescence Microscopy Identifies Low Molybdenum Concentrations in Foetal Growth Restriction, Postdate Delivery and Stillbirth.

Placental health and foetal development are dependent upon element homeostasis. Analytical techniques such as mass spectroscopy can provide quantitative data on element concentrations in placental tissue but do not show spatial distribution or co-localisation of elements that may affect placental function. The present study used synchrotron-based X-ray fluorescence microscopy to elucidate element content and distribution in healthy and pathological placental tissue. The X-ray fluorescence microscopy (XFM) beamline at the Australian Synchrotron was used to image trace metal content of 19 placental sections from healthy term (n = 5, 37-39 weeks), foetal growth-restricted (n = 3, <32 weeks, birth weight <3rd centile), postdate (n = 7, >41 completed weeks), and stillbirth-complicated pregnancies (n = 4, 37-40 weeks). Samples were cryo-sectioned and freeze-dried. The concentration and distribution of fourteen elements were detected in all samples: arsenic, bromine, calcium, chlorine, copper, iron, molybdenum, phosphorous, potassium, rubidium, selenium, strontium, sulphur, and zinc. The elements zinc, calcium, phosphorous, and strontium were significantly increased in stillbirth placental tissue in comparison to healthy-term controls. Strontium, zinc, and calcium were found to co-localise in stillbirth tissue samples, and calcium and strontium concentrations were correlated in all placental groups. Molybdenum was significantly decreased in stillbirth, foetal growth-restricted, and postdate placental tissue in comparison to healthy-term samples (p < 0.0001). Synchrotron-based XFM reveals elemental distribution within biological samples such as the placenta, allowing for the co-localisation of metal deposits that may have a pathological role. Our pilot study further indicates low concentrations of placental molybdenum in pregnancies complicated by foetal growth restriction, postdate delivery, and stillbirth.

Using hyperspectral signatures for predicting foliar nitrogen and calcium content of tissue cultured little-leaf mockorange (Philadelphus microphyllus A. Gray) shoots

Determining foliar mineral status of tissue cultured shoots can be costly and time consuming, yet hyperspectral signatures might be useful for determining mineral contents of these shoots. In this study, hyperspectral signatures were acquired from tissue cultured little-leaf mockorange (Philadelphus microphillus) shoots to determine the feasibility of using this technology to predict foliar nitrogen and calcium contents. After using a spectroradiometer to take hyperspectral images for determining foliar N and Ca contents, the correlation between the hyperspectral bands, vegetation indices, and hyperspectral features were calculated from the spectra. Features with high correlations were selected to develop the models via different regression methods including linear, random forest (RF), and support vector machines. The results showed that non-linear regression models developed through machine learning techniques, including RF methods and support vector machines provided satisfactory prediction models with high R2 values (%N by RF with R2 = 0.72, and %Ca by RF with R2 = 0.99), that can estimate nitrogen and calcium content of little-leaf mockorange shoots grown in vitro. Overall, the RF regression method provided the most accurate and satisfactory models for both foliar N and Ca estimation of little-leaf mockorange shoots grown in tissue culture.

#289 Lipocalin-2 promotes cardiovascular calcification in chronic kidney disease by upregulating STAT3/NCOA4-mediated ferritinophagy and ferroptosis

Abstract Background and Aims Cardiovascular calcification (CVC) is a common complication of chronic kidney disease (CKD) and contributes to cardiovascular morbidity and mortality without any effective therapies. To date, the underlying mechanism of CKD-CVC has not been elucidated. Recent studies suggest that ferroptosis is a novel programmed cell death that may play a role in the process of CKD-CVC, but the mechanism is largely unclear. Ferritinophagy is an important inducer of ferroptosis that is regulated by nuclear receptor coactivator 4 (NCOA4). However, the relationship between ferritinophagy and CKD-CVC has not been explored. Lipocalin-2 (LCN2) is an iron-trafficking protein that has been associated with both osteogenesis and ferroptosis, but the exact role and molecular mechanism of LCN2 in CKD-CVC needs to be explored. Method A cross-sectional clinical study was utilized to examine the association between LCN2 expression and CKD-CVC in serum and calcified radial arteries of CKD patients. LCN2 knockout mice, their wild type littermates and mice infected with VSMCs-targeted adeno-associated virus encoding LCN2 gene or negative control gene were all fed by the high adenine and phosphate diet to induce CKD-CVC.VSMCs transfected with LCN2-overexpressing lentivirus, LCN2-shRNA lentivirus or LCN2 siRNA and recombinant LCN2 stimulated VSMCs were treated under the condition of calcifying medium to investigate the role of LCN2 in CKD-CVC in vitro. Cardiovascular calcification was evaluated by Von-kossa staining and tissue calcium content assay. VSMCs calcification were checked by the Alizarin Red Staining and cellular calcium content assay. Cellular reactive oxygen species (ROS) were measured by the DCFDA assay. Lipid peroxidation was measured by the fluorescence of the fatty acid analog C11-BODIPY581/591 probe. Intracellular labile ferrous iron levels were measured by fluorescence of Phen Green SK probe and ferro-orange probe. Transmission electron microscopy was also used to examine mitochondrial change of ferroptosis. Results The cross-sectional study identified that LCN2 levels in serum and radial arteries were significantly increased as the severity of CKD-CVC increased. High adenine and phosphate diet intake provokes renal fibrosis and cardiovascular calcification in vivo. In vitro, five-days high phosphate sodium stimulation induced calcium deposition and osteoblastic trans differentiation of VSMCs. Meanwhile, high phosphate also increased the levels of ferroptosis in VSMCs as evidenced by decreased cell viability, iron and ROS accumulation, upregulated PTGS2 and MDA levels, reduced glutathione peroxidase 4 (GPX4) levels and significantly mitochondrial damage in VSMCs. Intriguingly, calcium deposition in VSMCs could be reversed by the ferroptosis inhibitor ferrostatin-1. LCN2 expression was significantly upregulated both in the aorta of mice and calcified VSMCs. Compared with WT mice, deletion of LCN2 inhibited cardiovascular calcification whereas VSMC-targeted LCN2 overexpression aggravated CKD-CVC. Consistently, LCN2 knockdown also alleviated calcium deposition of VSMCs. Meanwhile, inhibition of ferroptosis were observed after LCN2 silencing as evidenced by decreased ferrous and lipid oxidation while increased levels of GPX4. Mechanically, we demonstrated high phosphate increased the protein level of NCOA4 and downregulated FTH1, which was reversed by depletion of LCN2. Knockdown of NCOA4 partly alleviated the ferritin reduction, ferroptosis, and calcification in VSMCs, indicating that NCOA4-mediated ferritinophagy was required for VSMCs calcification. Furthermore, we found that the recombinant LCN2 treatment significantly upregulated phosphorylated STAT3. STAT3 signaling inhibitor abolished the recombinant LCN2 induced NCOA4 upregulation and calcification in VSMCs. Conclusion Our findings indicate that the pro-calcific effect of high phosphate is due to VSMCs ferroptosis mediated by LCN2 upregulation. LCN2 silencing alleviates CKD-CVC by suppressing the STAT3/ NCOA4/FTH1 signaling mediated ferritinophagy. LCN2 could serve as a candidate therapeutic strategy for CKD-CVC.

FRI116 Inhibition Of Mitochondrial Fission And Restoration Of Mitochondrial Function Attenuates Vascular Calcification

Abstract Disclosure: S. Kwon: None. M. Kim: None. S. Zerwa: None. S. Kim: None. B. Jueun: None. J. Jeon: None. I. Lee: None. Objectives: Vascular calcification is associated with cardiovascular disease mortality, especially in patients with diabetes mellitus and chronic kidney disease. One of proposed mechanisms for development of vascular calcification suggested mitochondrial dysfunction of vascular smooth muscle cells (VMSCs), especially excessive mitochondrial fission that led to apoptosis and tissue calcium deposit formation. In existing literature, Vitamin B1 inhibited mitochondrial fission and improved mitochondrial function. This study investigated whether inhibiting mitochondrial fission prevents vascular calcification in vitro and in vivo by using inorganic phosphate and cholecalciferol-induced vascular calcification models, respectively. Methods: VMSCs from thoracic aorta of 4-week-old rats were treated by 2.6mM inorganic phosphate and 2mM calcium chloride to induce calcification. 6-week-old male C57BL/6J mice were given vitamin B1 analogue solution or water with daily oral gavage for 13 days, then aortic calcification was induced by subcutaneous injection of 5.5×10-5 IU/kg cholecalciferol for 3 days before sacrifice. Cells and tissues were stained for calcium deposition, (van Kossa stain), apoptosis (TUNEL) and mitochondrial morphology (Mitotracker). Western blotting and quantitative real-time PCR were used to assess calcification pathways and mitochondrial function. Tissue calcium content, normalized with total protein contents, was measured to quantify the extent of calcification. Mitochondrial oxygen consumption ratio (OCR) and mitochondrial membrane potential (JC-1 dye staining) were assessed to analyze quantified mitochondrial function. Results: Calcium deposition in both in vivo and in vitro models were alleviated by vitamin B1 analogue through inhibition of mitochondrial fission and restoration of mitochondrial function. In addition, vitamin B1 analogue downregulated expression of genes related to calcification and osteogenesis, such as bone morphogenic protein 2, osteocalcin, osteopontin, and runt-related transcription factor 2. Conclusion: Prevention of mitochondrial dysfunction in VSMCs may be a viable therapeutic strategy for treatment of vascular calcification. Presentation: Friday, June 16, 2023

Prophylactic efficiency of the administration of vitamin, mineral and sorbent complexes on bone tissue in female rats against the background of chronic alcohol consumption

Among the general effects of alcohol use, it has a negative effect on the bone system, so the development of prevention methods is becoming an increasingly urgent problem. The present study was aimed at evaluating the efficiency of the preventive complexes for the bone system in chronic alcohol intoxication. The study was conducted on 2-month-old female rats for 104 days. Chronic alcoholism in animals was simulated by replacing drinking water with an ethanol solution, the concentration of which was gradually increased from 8–25%. The prophylactic was administered by introducing into the diet a complex of vitamins (P, C, D) and minerals (Cu, Mg, Zn, Se, Mn), the main component of which was crushed oyster shells processed with citric acid. The second prophylactic complex was the clay mineral montmorillonite in combination with vitamins P, C, D. The biochemical markers of resorption (elastase and acid phosphatase activity), osteogenesis (calcium content, alkaline phosphatase activity) and the state of the antioxidant system (catalase, superoxide dismutase, glutathione reductase activity, malondialdehyde content) were determined in bones (jaws and femurs). Chronic alcohol consumption led to an increase in the degree of atrophy of the alveolar process, a decrease in femur bone density due to a decrease in the mineral component in bone tissue, and did not affect the state of the lumbar vertebrae. Chronic alcohol intoxication led to a decrease in the level of calcium in the blood serum of rats, and to a decrease in the alkaline phosphatase activity and the calcium content in the bone tissue of the jaws and femur against the background of increases in the activities of acid phosphatase and elastase. A significant decrease in the activity of the main antioxidant enzymes (superoxide dismutase, catalase and glutathione reductase) in bone tissue of animals against the background of an increase in the malondialdehyde content under conditions of chronic alcoholization has been established. The use of the complex with crushed oyster shells effectively prevented atrophy ofthe alveolar process in the jaws, did not affect the morphometric parameters in the femur and vertebrae, but normalized the activities of serum alkaline phosphatase and catalase, bone elastase, acid phosphatase, superoxide dismutase and glutathione reductase against the background of restoring the levels of calcium and malondialdehyde both in the serum and in the bone tissue of rats subjected to chronic alcoholization. Prophylactic administration of the vitamin complex with montmorillonite had a much weaker effect on the studied indicators. The obtained research results allow us to conclude that the osteoprotective and antioxidant efficiency of the complex with crushed oyster shells is more pronounced than that of montmorillonite under conditions of chronic alcohol intoxication.

Leaf Tissue Macronutrient Standards for Northern Highbush Blueberry Grown in Contrasting Environments

Leaf tissue testing is a useful tool for monitoring nutrient requirements in northern highbush blueberry (Vaccinium corymbosum L.; abbreviated as "blueberry") but may require adaptation to specific growing environments. The objective of this study was to evaluate macronutrient concentrations in early-, mid-, and late-season blueberry cultivars grown in two contrasting environments, specifically eastern and western Washington. Climate and soil conditions between these two regions differ tremendously with eastern Washington being more arid with naturally calcareous soils lower in soil organic matter. Sampling was conducted over a 3-year period in commercial fields. Leaf tissue nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S) concentrations were affected by year (Y), growing region (R), cultivar (C), and Day of Year (DOY) that the samples were collected with many interactions. Leaf nutrient concentrations were higher, on average, in western than eastern Washington except for Ca and Mg, indicating sufficiency levels should differ between these regions. Leaf macronutrients generally stabilized between DOY 212-243 (1-31 August), suggesting this period is optimal for tissue sampling. Findings from this study demonstrate the importance of considering regional effects and may be applicable for blueberry cultivated in similar pedo-climactic conditions around the world.

Evaluation of Mehlich-3 as a Multi-Element Extractant of Micronutrients and Sulfur in a Soil–Ryegrass System Amended with Varying Biochar Rates from Two Feedstocks

Mehlich-3 (M-3) is used as a universal nutrient extractant due to its ability to simultaneously extract multiple elements. This study aimed to assess M-3 for the simultaneous determination of plant-available zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), boron (B), and sulfate (SO4-S) in a soil amended with switchgrass- (SGB) and poultry litter-derived biochars (PLB), which were used to vary soil pH values (5.7–7.6) and organic carbon (OC) content (2.0–5.5%) in the short-term. Soil and ryegrass (Lolium perenne) were sampled from a growth chamber experiment and analyzed for plant-available and tissue phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), micronutrients (B, Cu, Fe, Mn, and Zn), and sulfur contents. The commonly accepted extractants diethylenetriaminepentaacetic acid (DTPA), for micronutrients, and 0.008 M monocalcium phosphate (MCP), for SO4-S, were used for the evaluation. Relationships between M-3 and DTPA were not reliable for micronutrient availability, although highly significant relationships for Zn and Cu were found. However, M-3-extractable S was highly correlated with S contents in ryegrass tissues regardless of the treatments and provided a 1:1 relationship between MCP and M-3. This offers the potential to eliminate MCP by simply adding S determination after extraction with M-3. Although this research evaluated the d-index for an easier linear relationship between the traditional and proposed methods, more research using several soil samples is needed to establish models and find conversion equations for micronutrients and SO4-S between DTPA-sorbitol, MCP, and M-3.

Iron overload impairs renal function and is associated with vascular calcification in rat aorta

Vascular calcification (VC) has been associated with a risk of cardiovascular diseases. Iron may play a critical role in progressive VC. Therefore, we investigated the effects of iron overload on the aorta of rats. A rat model of iron overload was established by intraperitoneal injection of Iron-Dextran. The levels of iron, calcium, and ALP activity were detected. Von Kossa staining and Perl’s staining were conducted. The expression of iron metabolism-related and calcification related factors were examined in the aortic tissue of rats. The results showed serum and aortic tissue iron were increased induced by iron overload and excessive iron induced hepatic and renal damage. In iron overload rats, the expression of divalent metal transporter 1 (DMT1) and hepcidin were higher, but ferroportin1 (FPN1) was lower. Von Kossa staining demonstrated calcium deposition in the aorta of iron overload rats. The calcium content and ALP activity in serum and aortic tissue were increased and iron level in aortic tissue highly correlated with calcium content and ALP activity. The expressions of the osteogenic markers were increased while a decrease of Alpha-smooth muscle actin (α-SMA) in the aortic tissue of iron overload rats. IL-24 was increased during the calcification process induced by iron. Overall, we demonstrated excessive iron accumulation in the aortic tissue and induced organs damage. The iron metabolism-related factors were significantly changed during iron overload. Moreover, we found that iron overload leads to calcium deposition in aorta, playing a key role in the pathological process of VC by mediating osteoblast differentiation factors.

Evaluation of real-time nutrient analysis of fertilized raspberry using petiole sap.

The time delay in receiving conventional tissue nutrient analysis results caused red raspberry (Rubus idaeus L.) growers to be interested in rapid sap tests to provide real-time results to guide immediate nutrient management practices. However, sap analysis has never been conducted in raspberry. The present work aimed to evaluate the relationship of petiole sap nitrate (NO3–), potassium (K+), and calcium (Ca2+) concentrations measured using compact ion meters and leaf tissue total nitrogen (TN), potassium (K), and calcium (Ca) concentrations measured using conventional tissue nutrient analysis. The relationship of petiole sap NO3– and leaf tissue TN concentrations with plant growth and production variables was also explored. Fertilizer treatments of urea were surface applied to raised beds of established “Meeker” floricane red raspberry plots at control, low, medium, and high rates (0, 34, 67, and 101 kg N ha–1, respectively) in 2019 and 2020. The experiment was arranged in a randomized complete block design with three replications. Whole leaves were collected from representative primocanes in mid- and late- July and August 2019 and 2020 (i.e., four sampling time points per year). At each sampling time point, a subsample of leaves was used for petiole sap analyses of NO3–, K+, and Ca2+ concentrations using compact ion meters, and conventional tissue testing of leaf tissue TN, K, and Ca concentrations, respectively. There were no interactions between N fertilizer rate and year nor between N fertilizer rate and sampling time. No significant differences were found due to N fertilizer rate for petiole sap NO3–, K+, Ca2+ nor leaf tissue TN, K, Ca concentrations. However, significant year and sampling time effects occurred in measured petiole sap and leaf tissue nutrient concentrations. Overall, the correlations between petiole sap NO3– and leaf tissue TN, petiole sap Ca2+ and leaf tissue Ca, petiole sap K+ and leaf tissue K concentrations were non-strong and inconsistent. Future research is warranted as the interpretation of correlations between raspberry petiole sap and leaf tissue nutrient concentrations were inconclusive.

Increasing calcium scarcity along Afrotropical forest succession.

Secondary forests constitute an increasingly important component of tropical forests worldwide. Although cycling of essential nutrients affects recovery trajectories of secondary forests, the effect of nutrient limitation on forest regrowth is poorly constrained. Here we use three lines of evidence from secondary forest succession sequences in central Africa to identify potential nutrient limitation in regrowing forests. First, we show that atmospheric phosphorus supply exceeds demand along forest succession, whereas forests rely on soil stocks to meet their base cation demands. Second, soil nutrient metrics indicate that available phosphorus increases along the succession, whereas available cations decrease. Finally, fine root, foliar and litter stoichiometry show that tissue calcium concentrations decline relative to those of nitrogen and phosphorus during succession. Taken together, these observations suggest that calcium becomes an increasingly scarce resource in central African forests during secondary succession. Furthermore, ecosystem calcium storage shifts from soil to woody biomass over succession, making it a vulnerable nutrient in the wake of land-use change scenarios that involve woody biomass export. Our results thus call for a broadened focus on elements other than nitrogen and phosphorus regarding tropical forest biogeochemical cycles and identify calcium as a scarce and potentially limiting nutrient in an increasingly disturbed and dynamic tropical forest landscape.

Analysis and Characterization of Lactobacillus paragasseri and Lacticaseibacillus paracasei: Two Probiotic Bacteria that Can Degrade Intestinal Oxalate in Hyperoxaluric Rats.

In the present study, we characterized the probiotic properties of two commercially available bacterial strains, Lactobacillus paragasseri UBLG-36 and Lacticaseibacillus paracasei UBLPC-87, and evaluated their ability to degrade oxalate in vitro and in a hyperoxaluria-induced nephrolithiasis rat model. UBLG-36 harboring two oxalate catabolizing genes, oxalyl coenzyme A decarboxylase (oxc) and formyl coenzyme A transferase (frc), was previously shown to degrade oxalate in vitro effectively. Here, we show that UBLPC-87, lacking both oxc and frc, could still degrade oxalate in vitro. Both these strains harbored several potential putative probiotic genes that may have conferred them the ability to survive in low pH and 0.3% bile, resist antibiotic stress, show antagonistic activity against pathogenic bacteria, and adhere to epithelial cell surfaces. We further evaluated if UBLG-36 and UBLPC-87 could degrade oxalate in vivo and prevent hyperoxaluria-induced nephrolithiasis in rats. We observed that rats treated with 4.5% sodium oxalate (NaOx) developed hyperoxaluria and renal stones. However, when pre-treated with UBLG-36 or UBLPC-87 before administering 4.5% NaOx, the rats were protected against several pathophysiological manifestations of hyperoxaluria. Compared to the hyperoxaluric rats, the probiotic pre-treated rats showed reduced urinary excretion of oxalate and urea (p < 0.05), decreased serum blood urea nitrogen and creatinine (p < 0.05), alleviated stone formation and renal histological damage, and an overall decrease in renal tissue oxalate and calcium content (p < 0.05). Taken together, both UBLG-36 and UBLPC-87 are effective oxalate catabolizing probiotics capable of preventing hyperoxaluria and alleviating renal damage associated with nephrolithiasis.

Effectiveness of postharvest calcium salts applications to improve shelf-life and maintain apricot fruit quality during storage

Fresh apricot is a nutritious and popular fruit because of its special aroma and taste. However, high ripening rates and susceptibility to mechanical injury and postharvest diseases limit its shelf life. Therefore, the effect of immersion in different calcium salts solution on the qualitative and biochemical characteristics of fresh apricot fruit ʻShahroudi’ cv was evaluated. Treatments were solutions of calcium chloride (CaCl2), calcium nitrate Ca(NO3)2, and calcium sulfate (CaSO₄) at a concentration of 1 or 2%. Distilled water was used as a control. Fruits were immersed in water or calcium salts solution for 2 min, air-dried, and then stored at 2±1 °C for three weeks. However, the highest firmness was related to 2% CaCl2 treatment, which was about 60% higher than control, followed by 1% Ca(NO3)2 treatment (50% more than control). Also, the lowest Total Soluble Solids value was 10.46%, which was obtained from 2% CaCl2 and the highest value was obtained in control (15.1%). Besides, the mentioned treatments improved the nutritional value of apricot fruit by increasing total phenolic compounds, and tissue calcium content. The shelf life was 15.67 days in control, while 2% CaCl2 treatment doubled (35.33 days) the shelf life of apricot fruit. In general, the best result was obtained using CaCl2 at 2% treatment for 2 min, which may be applied as a postharvest treatment to improve the storage life of apricot fruit ʻShahroudi’ cv.

Dietary magnesium supplementation inhibits abdominal vascular calcification in an experimental animal model of chronic kidney disease.

ABSTRACTBackgroundVascular calcification is a key process involved in cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Magnesium supplementation may counteract vascular calcification. In this study we aimed to determine whether increased dietary magnesium intake inhibits vascular calcification in CKD in vivo and explore the mechanisms underlying these effects.MethodsSprague Dawley rats were partially nephrectomized and fed a diet with high phosphate and either high or normal magnesium content for 16 weeks. The primary outcome was the tissue calcium content of the aorta in the high versus normal dietary magnesium group. In addition, we analysed plasma mineral concentrations, aortic vascular calcification identified with von Kossa staining, calcium apposition time and aortic expression of genes related to vascular calcification.ResultsThe number of animals in the highest tissue calcium content tertile was significantly lower in the abdominal aorta [1 (10%) versus 6 (55%); P = .03] in the high versus normal dietary magnesium group, but did not differ in the aortic arch and thoracic aorta. Von Kossa staining and calcium apposition time corresponded to these results. The median tissue calcium content was not significantly different between the groups. Serum phosphate concentrations and expression of osteogenic markers in the aorta did not differ between the groups.ConclusionsThis study demonstrates that increased dietary magnesium inhibits abdominal vascular calcification in an experimental animal model of CKD in vivo. These are promising results for CKD patients and further study is needed to identify the mechanisms involved and to determine the clinical relevance in patients.

The Rhizobium and calcium fertilizer application to peanut plant in dry land

One of the main problems of peanut planting in dry land is a lack of nitrogen and calcium availability. Efforts to increase the nitrogen and calcium availability for peanut farming in dry land is needed and one possible approach is by application of Rhizobium and calcium fertilizers. This research was conducted to determine the effect of the application of Rhizobium (Nodulin) and calcium fertilizers on growth and yield of peanut plants in dry land. Two experiments were conducted, one in a greenhouse using a completely randomized design and another experiment in the field using a randomized block design. The treatments were with the application of Nodulin, without Nodulin, with calcium fertilizer and without calcium fertilizer. The results showed that the application of calcium and Nodulin was able to increase the number of root nodules and peanut growth. Nodulin and calcium fertilizers increased the dry pod weight of 2.177 g per 6 m2 or 3.7 tons.ha-1. The application of Nodulin and calcium was also able to increase the nitrogen and calcium content of leaf tissue up to 18.9% and 20.9%, respectively.

Effects of mode and timing of calcium chloride application on tissue calcium concentration and acceptability of mango fruits

Mango (Mangifera indica L) production in Kenya directly supports approximately 200,000 farmers and many other beneficiaries. Despite this, its production suffers from post-harvest losses due to the fruits' short shelf life in ambient conditions. Calcium maintains cell integrity, strengthens the cell wall, membrane structure, and thus increases shelf life. A completely randomized block design with a split plot arrangement was used to compare the effect of spraying and immersion of ‘Van Dyke' mango fruits at maturity or 15 days later in calcium chloride at different concentrations (0.5%, 1%, 1.5%, or 0%) and times on the fruit ripening rate and organoleptic acceptance. The peel firmness (N), total soluble solids (0Brix), flesh color (Ho), beta carotene (mg/100ml), and carbon dioxide evolution (ml/kg/hr) of fruits were determined at time 0 and every two days for up to eight days in ambient conditions. Additionally, organoleptic characteristics, flesh firmness, calcium concentration (g/mg), and their correlations were determined. Fruits immersed in calcium chloride at maturity had higher retained peel firmness (10.6 N, 10.3 N), deeper flesh color (37.45, 36.78), lower total soluble solids (14, 13.8), a lower carbon dioxide evolution (30.7 ml/kg/hr), higher beta carotene and higher flesh calcium concentration than fruits exposed to other treatments. Fruits sprayed at maturity outperformed those sprayed 15 days later in the studied parameters. Flesh calcium content correlated positively with flesh firmness (r= 0.913, r= 0.852), flesh color (r= 0.828, r= 0.841), fruit aroma (r=0.8199, r=0.841), and negatively with skin shriveling (r=-0.778, r=-0.806) and fruit flavor (r=-0.811, r=-0.829). Flesh firmness correlated negatively with skin shriveling (r=-0.868, r=-0.788) and fruit flavor (r=-0.8869, r=-0.821), but positively with peel color (r=0.9115, r=0.856) and aroma (r=0.907, r=0.848). Skin shriveling was found to have a negative relationship with peel color (r=-0.944, r=-0.93) and aroma (r=-0.944, r=-0.938), but a positive relationship with fruit flavor (r=0.933, r=0.947). Peel color correlated positively with aroma (r=0.979, r=0.977) and negatively with fruit flavor (r=-0.962, r=-0.950), respectively. Despite the effectiveness of post-harvest calcium chloride immersion in extending fruit shelf life, optimal use is advised to avoid deteriorated pulp flavor and increased shriveling. More research is needed to determine how calcium chloride can be made available to the fruit while it is still attached to the tree.

Pre-ischemic Lactate Levels Affect Post-ischemic Recovery in an Isolated Rat Heart Model of Donation After Circulatory Death (DCD).

Introduction: Donation after circulatory death (DCD) could substantially improve donor heart availability. In DCD, the heart is not only exposed to a period of warm ischemia, but also to a damaging pre-ischemic phase. We hypothesized that the DCD-relevant pre-ischemic lactate levels negatively affect the post-ischemic functional and mitochondrial recovery in an isolated rat heart model of DCD.Methods: Isolated, working rat hearts underwent 28.5′ of global ischemia and 60′ of reperfusion. Prior to ischemia, hearts were perfused with one of three pre-ischemic lactate levels: no lactate (0 Lac), physiologic lactate (0.5 mM; 0.5 Lac), or DCD-relevant lactate (1 mM; 1 Lac). In a fourth group, an inhibitor of the mitochondrial calcium uniporter was added in reperfusion to 1 Lac hearts (1 Lac + Ru360).Results: During reperfusion, left ventricular work (heart rate-developed pressure product) was significantly greater in 0.5 Lac hearts compared to 0 Lac or 1 Lac. In 1 vs. 0.5 Lac hearts, in parallel with a decreased function, cellular and mitochondrial damage was greater, tissue calcium content tended to increase, while oxidative stress damage tended to decrease. The addition of Ru360 to 1 Lac hearts partially abrogated the negative effects of the DCD-relevant pre-ischemic lactate levels (greater post-ischemic left ventricular work and less cytochrome c release in 1 Lac+Ru360 vs. 1 Lac).Conclusion: DCD-relevant levels of pre-ischemic lactate (1 mM) reduce contractile, cellular, and mitochondrial recovery during reperfusion compared to physiologic lactate levels. Inhibition of mitochondrial calcium uptake during early reperfusion improves the post-ischemic recovery of 1 Lac hearts, indicating calcium overload as a potential therapeutic reperfusion target for DCD hearts.

Dietary organic zinc promotes growth, immune response and antioxidant capacity by modulating zinc signaling in juvenile Pacific white shrimp (Litopenaeus vannamei)

An 8-week feeding trial was conducted to evaluate effects of dietary organic zinc (zinc amino acid chelate) on growth performance, mineral bioaccumulation in whole body, hepatopancreas and carapace, innate immune response and antioxidant capacity of juvenile Pacific white shrimp Litopenaeus vannamei. Five isonitrogenous and isolipidic diets were formulated to contain different zinc levels of 46.4 (basal diet), 65.5, 85.9, 108.4 and 130.6 mg kg−1. Dietary zinc level significantly influenced growth and feed utilization, with the lowest weight gain and highest feed conversion ratio observed in shrimp fed the basal diet. The optimal dietary zinc requirement was estimated to be 104.8 mg kg-1 for juvenile Pacific white shrimp. Shrimp fed the diet containing 130.6 mg kg−1 Zn had the highest zinc concentration in hepatopancreas and carapace, but there were no significant differences in calcium or phosphorus concentration in tissues. Dietary Zn increased the activities of lysozyme, alkaline phosphatase and polyphenol oxidase in hepatopancreas. Shrimp fed the diets supplemented with zinc had significantly higher activity of Cu/Zn SOD and lower content of malondialdehyde in hepatopancreas. The expression levels of toll, imd, lzm, proPO and alp involved in immunity and Cu/Zn sod related to oxidation resistance were up-regulated. Zinc also promoted the expression levels of mt and mtf-1, and up-regulated the expression of SLC39 family genes (zip3, zip9, zip11, zip14) in hepatopancreas. These data provided novel insights in the potential mechanism of organic zinc-induced enhancement of immunity and antioxidant capacity in Pacific white shrimp.

Manipulating Phosphorus, Calcium, and Magnesium Utilization by Growing Lambs Using Natural Zeolite (Clinoptilolite)

A total of 24 three-month-old lambs with an average weight of 23 ± 1.5 kg were used in this study and fed a complete diet supplemented with natural zeolite at 1% and 2% of feed weight to evaluate the effect of zeolite on calcium (Ca), phosphorus (P), and magnesium (Mg) concentration in tissues (kidney, liver, and muscle), rumen fluid, and blood. Adding zeolite at 2% to the diet resulted in an increase (p &lt; 0.05) in body weight but a depressed feed conversion ratio. Phosphorus digestibility was significantly (p &lt; 0.05) increased with the addition of zeolite while the digestibility of Ca and Mg remained unaffected (p &gt; 0.05). The concentration of Ca, Mg, and P in the liver remained unchanged (p &gt; 0.05) with the addition of zeolite. The addition of zeolite led to a decrease (p &lt; 0.05) in the Ca concentration in the kidney and muscle, whereas the Ca concentration in lambs receiving diets supplemented with 2% zeolite (123.13 and 48.49 µg/g) was significantly (p &lt; 0.05) higher than supplementation at 1% (120.13 and 45.66 µg/g, respectively, for kidney and muscle). Furthermore, serum and rumen fluid concentrations of P, Ca, and Mg exhibited no significant differences upon the addition of zeolite to the diet. Conclusively, diet supplementation by zeolite at 2% improves performance and especially P digestibility, which may result in the reduction in minerals in lambs’ waste and consequently a reduction in environmental pollution.

Effects of supplemental cocoa husk on testicular characteristics of pigs

48 Large white boars with an average weight of 35 kg were randomly allocated to 6 experimental&#x0D; rations compounded from conventional ingredients with maize and maize offal as the major energy&#x0D; Sources. Ration 1, (R1) served as the control and contained no Cocoa husk (CH) supplement.&#x0D; Rations 2.3.4,5 and 6 (R2-R6) contained 5%, 10%, 15% 20% and 25% inclusion levels of cocoa&#x0D; husk, respectively effectively replacing maize offal at 20%, 40%, 60%, 80% and 100%, respectively. Significant effects (P&lt;0.05) were observed on testicular weights with a mean of 150g in the control Digs and 168g in the pigs on 5% CH diet. Further increases in the dietary intake of CH decreased testicular weight. The weight of the tunica albuginea increased initially with increasing CH inclusion up to 10% level (17.8g) thereafter gradually decreasing with increasing CH to10. 6g at 25% CH level. The cauda epididymal weight also exhibited a similar trend. Gonadal sperm reserves were influenced by dietary CH rising from 2.74x109 in the control animals to 13.05 x109 in the 10% CH supplemented group and falling thereafter to 3.21 x109 at 20%CH supplementation. Epididymal reserves were also similar in concentration to the testicular sperm concentrations. Significant dimly effects were observed in calcium, potassium and sodium concentrations in the gonads. Calcium content of gonadal tissues decreased with increasing CH level. Potassium and sodium however rose linearly with increasing CH incorporation zip till 20% incorporation level, and declined sharply in the pigs fed the 25%CH diets. In summary, cocoa husk supported optimum testicular characteristics maximally in mature boars up to 10 % level of incorporation and is tolerated without adverse effects on testicular characteristics up to 15% level.

Aldosterone is a possible new stimulating factor for promoting vascular calcification.

Background: Aldosterone is an important hormone in the renin-angiotensin-aldosterone system (RAAS), and playing a pivotal role in the development of hypertension, heart failure, and other cardiovascular diseases. Material and method: In this study, the role of the aldosterone in vascular calcification was underwent in rat model compared with other drugs. Vascular calcification, calcium concentration, activity of alkaline phosphatase (ALP), aldosterone, Urotensin II, mineralocorticoid receptor (MR) and Osteopontin (OPN) were detected or confirmed by the von Kossa staining, colorimetric assays, immunohistochemistry and radioimmunoassay, separately. Result: Results revealed that the aldosterone was significantly increased compared calcification + aldosterone group with calcification group, whereas it was notably decreased in calcification + Spironolactone group in the aortic wall. Compared with control group and aldosterone group, calcium content in vascular tissues was increased in calcification group and calcification + aldosterone group. As the immunoreactivity of the MR, OPN, Urotensin II, IL-6, monocyte chemoattractant protein-1, and deposition of collagen in calcification group and aldosterone group, they all were increased slightly, but were significantly increased in calcification + aldosterone group. Conclusion: It is implied that aldosterone may be involved in the development of vascular calcification, however, the mechanism needs to be further studied.