High Levels Of Ca Research Articles

Amyloid β, α-synuclein and the c subunit of the ATP synthase: Can these peptides reveal an amyloidogenic pathway of the permeability transition pore?

Mitochondrial Permeability Transition (PT) is a phenomenon of increased permeability of the inner mitochondrial membrane in response to high levels of Ca2+ and/or reactive oxygen species (ROS) in the matrix. PT occurs upon the opening of a pore, namely the permeability transition pore (PTP), which dissipates the membrane potential uncoupling the respiratory chain. mPT activation and PTP formation can occur through multiple molecular pathways. The specific focus of this review is to discuss the possible molecular mechanisms of PTP that involve the participation of mitochondrially targeted amyloid peptides Aβ, α-synuclein and c subunit of the ATP synthase (ATPase). As activators of PTP, amyloid peptides are uniquely different from other activators because they are capable of forming channels in lipid bilayers. This property rises the possibility that in this permeabilization pathway the formation of the channel involves the direct participation of peptides, making it uniquely different from other PTP induction mechanisms. In this pathway, a critical step of PTP activation involves the import of amyloidogenic peptides from the cytosol into the matrix. In the matrix these peptides, which would fold into α-helical structure in native conditions, interact with cyclophilin D (CypD) and upon stimulation by elevated ROS and/or the Ca2+ spontaneously misfold into β-sheet ion conducting pores, causing PTP opening.

Performance Status Modifies the Association Between Vitamin D Receptor Activator and Mortality or Fracture: A Prospective Cohort Study on the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry.

Immobilization osteoporosis is characterized by excess bone resorption. Vitamin D receptor activators (VDRA) might have adverse effects in immobilized patients. The objective of this study was to elucidate the impact of performance status (PS) on the associations between VDRA use and outcomes among hemodialysis patients. This is a prospective cohort study. Adults on hemodialysis in the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry were included. Exposure of interest was the use of VDRA. Outcomes were all-cause mortality and hip fracture. Associations between VDRA use and mortality or hip fractures were examined by Cox and Poisson regression analyses, respectively. Among 208,512 subjects, 128,535 were on VDRA. Poor PS was associated with higher calcium (Ca), lower parathyroid hormone, and higher alkaline phosphatase levels. The association between higher Ca levels and VDRA use was stronger among those with poor PS (p interaction 0.007). Adjusted hazard ratio (HR) (95% confidence interval [CI]) for mortality and incidence rate ratio (IRR) for hip fracture was 1.02 (95% CI, 0.99-1.05) and 0.93 (0.86-1.00) among users of VDRA, respectively. The VDRA use was associated with lower mortality and incidence of hip fractures among subjects with good PS but not among subjects with poor PS (p interaction 0.03 and 0.05). Effect modification by PS was observed for cardiovascular (CV) mortality but not for non-CV mortality. In conclusion, VDRA use was associated with better outcomes only among those with good PS. These results suggest that bone and mineral disorders among hemodialysis patients should be treated differently, depending on their performance status. © 2022 American Society for Bone and Mineral Research (ASBMR).

Enhanced Removal of Heavy Metals from Water by Hydrous Ferric Oxide-Modified Biochar.

Biochar has become an attractive adsorbent for heavy metal removal, but its application potential is very limited because of the relatively low adsorption capacity and poor selectivity. In the present study, we decorated the biochar (BC) by impregnating hydrous ferric oxide (HFO) within the pore of biochar and consequently obtained a new hybrid adsorbent denoted as HFO-BC. The results show HFO-BC exhibited excellent performance to two representative heavy metals, i.e., Cd(II) and Cu(II), with maximal experimental sorption capacities of 29.9 mg/g for Cd(II) and 34.1 mg/g for Cu(II). HFO-BC showed satisfactory anti-interference ability for Cd(II) and Cu(II) removal in the presence of high levels of Ca(II) and Mg(II) owing to the specific inner-sphere complexation between the immobilized HFO and Cd(II) and Cu(II), which was probed by XPS analysis. Cd(II) and Cu(II) removal onto HFO-BC experienced two distinct stages prior to be adsorbed, i.e., migration from solution to the outside surface of adsorbent and pore diffusion and approached equilibrium within 100 min. In the laboratory-scale small column adsorption experiment, HFO-BC can generate ∼129 and 300 BV effluents for Cd(II) and Cu(II), equivalent to 774- and 1854-fold of its own weight, to meet their treatment standards. Moreover, the exhausted HFO-BC can be effectively regenerated using HCl–CaCl2 binary solution with a desorption rate more than 95%. All results validate that impregnating HFO inside the pores of BC is a promising approach to promote the practical applicability of BC for removing heavy metals from the polluted water.

Novel Crown Cement Containing Antibacterial Monomer and Calcium Phosphate Nanoparticles.

Oral biofilm accumulation at the tooth–restoration interface often leads to recurrent dental caries and restoration failure. The objectives of this study were to: (1) develop a novel bioactive crown cement containing dimethylaminohexadecyl methacrylate (DMAHDM) and nano-sized amorphous calcium phosphate (NACP), and (2) investigate the mechanical properties, anti-biofilm activity, and calcium (Ca2+) and phosphate (PO43−) ion release of the crown cement for the first time. The cement matrix consisted of pyromellitic glycerol dimethacrylate and ethoxylated bisphenol-A dimethacrylate monomers and was denoted PEHB resin matrix. The following cements were tested: (1) RelyX luting cement (commercial control); (2) 55% PEHB + 45% glass fillers (experimental control); (3) 55% PEHB + 20% glass + 25% NACP + 0% DMAHDM; (4) 52% PEHB + 20% glass + 25% NACP + 3% DMAHDM; (5) 51% PEHB + 20% glass + 25% NACP + 4% DMAHDM; (6) 50% PEHB + 20% glass + 25% NACP + 5% DMAHDM. Mechanical properties and ion release were measured. Streptococcus mutans (S. mutans) biofilms were grown on cements, and colony-forming units (CFUs) and other biofilm properties were measured. The novel bioactive cement demonstrated strong antibacterial properties and high levels of Ca2+ and PO43− ion release to remineralize tooth lesions. Adding NACP and DMAHDM into the cement did not adversely affect the mechanical properties and dentin bonding strength. In conclusion, the novel NACP + DMAHDM crown cement has excellent potential for restoration cementation to inhibit caries by suppressing oral biofilm growth and increasing remineralization via Ca2+ and PO43− ions. The NACP + DMAHDM composition may have wide applicability to other biomaterials to promote hard-tissue formation and combat bacterial infection.

Potential Antioxidant Activity of Calcium and Selected Oxidative Stress Markers in Lead- and Cadmium-Exposed Workers

Occupational lead (Pb) and cadmium (Cd) exposure occurs during processing and casting of nonferrous metals such as zinc. In contrast to Pb and Cd, Ca is essential for living organisms due to its important role in a multitude of functions, from cell signaling to bone growth. Pb and Cd exposure affects calcium metabolism in various ways. The aim of this study was to investigate the blood levels of Pb, Cd, and Ca and the levels of selected oxidative stress biomarkers in workers exposed to Pb and Cd. Population groups included 264 male employees in a lead-zinc smelter. The study population was divided into two subgroups based on the median of Ca serum level (2.42 mmol/l): the low-Ca-level group (L-Ca group) and the high-Ca-level group (H-Ca group). Ca level was significantly higher in the H-Ca group than in the L-Ca group due to the study design (by 26%). The level of zinc protoporphyrin (ZPP) was significantly higher in the L-Ca group than in the H-Ca group by 13%, while the blood lead levels (PbB) were similar in the examined groups. The level of cadmium (CdB) was significantly higher in the L-Ca group than in the H-Ca group by 33%. From oxidative stress markers in serum, only the levels of malondialdehyde (MDA) and ceruloplasmin (CER) were significantly higher in the L-Ca group than in the H-Ca group, by 12% and 4%, respectively. The correlation analysis showed negative correlations between Ca level and the levels of PbB, ZPP, CdB, and MDA. The presented results indicate that Ca level modulates the serum concentration of Cd and has an impact on Pb-induced impairment of heme synthesis. The higher Ca levels may lead to a decrease in the concentration of lipid peroxidation products. Moreover, serum calcium level seems to be able to modify the level of acute-phase proteins. Obtained results suggest that higher Ca level may be useful in reducing Cd level in occupationally exposed workers.

Mineral and toxic metal composition in three commercial species of Gadidae

The high nutritional value of fish stems from its high contents of protein, amino acids, essential fatty acids, vitamins, and minerals. The aim of the present study was to assess the nutritional value of cod in terms of minerals and to estimate the risk posed by the toxic metals contained in the muscles of fish belonging to the family Gadidae. Individuals of three subspecies of cod were examined: Atlantic cod, Gadus morhua morhua L., Baltic cod, Gadus morhua callarias L., and saithe, Pollachius virens, Linnaeus, 1758. Macro and microelements occur in Gadidae in varied quantities. The mineral concentrations of the fish examined in the current study occurred in the following sequence: K > P > Na > Mg > Ca > Zn > Fe > Sr > Cu > Se > Mn > Cr. P and K dominated in all the specimens. Na and As occurred in Atlantic cod at high levels, while saithe muscles contained high levels of Na, Mg, Zn, and Fe, and Baltic cod contained high levels of Ca and Sr. Cod were an important source of P and Se and a moderately good source of K, Mg, and Zn. The remaining minerals provided a share of several percent of the recommended daily intake (RDI). Low levels of Cd, Pb, Hg, and toxic, inorganic As compounds posed no risk to the health of consumers. The lack of risk was confirmed by the low values of estimated daily intake (EDI) values, target hazard quotient (THQ) values below 1, and carcinogenic risk (CR) coefficients that were within a range from 10−6 to 10−4.

Improvement of a hydrometallurgical process for recovering Mn from electric-arc furnace slag

Electric-arc furnace (EAF) slag is a waste generated in large quantities by the steelmaking industry. This waste contains high levels of Ca, Fe, Mn and Si. In the present study, an improved hydrometallurgical process was demonstrated for efficient recovery of Mn from EAF slag. Firstly, the EAF slag was dissolved in a mixture of nitric and hydrochloric acids to remove the insoluble Si-containing mixture. The generated leaching acid contained 6 g/L Mn, 26.9 g/L Ca, 15.9 g/L Fe and small amounts of other impurities. Secondly, Ca precipitated into anhydrite when concentrated sulphuric acid was added, and the residual Ca ion concentration was 213 mg/L. Thirdly, after Ca was precipitated, nearly 100% Fe was removed as hematite nanoparticles with 67.7% of Fe during the hydrometallurgical processes by adding methanol at an Mmethanol/Mnitrate ratio of 0.75, the retention rate of Mn was higher than 98.5%. Without adding methanol, only 54.8% of Fe was precipitated as an irregular hematite block. Fourthly, the residual Mn content is 5.8 g/L, which was recovered as hausmannite with Mn content of 60.3% when solution pH is adjusted to 8. Hydrolysis of Fe was not observed at 80 °C but accelerated when temperature was higher than 140 °C. Ethanol exhibited removal efficiency of Fe similar to that of methanol, but the optimal Methanol/Mnitrate molar ratio was 0.3, which was 2/5 that of methanol. By using the improved method, high-purity hausmannite product and hematite by-product were effectively recovered from the EAF slag without generating secondary waste.

Influence of season and breed on serum mineral levels in sheep.

The main objective of this study was to assess the concentration of various minerals (Ca, P, Mg, Cu, Zn, Fe) in the blood of sheep, followed by biochemical analysis in order to reveal possible associations of season and breed. The study was conducted by sampling four herds: Suffolk (n=20), Merino (n=20), Lithuanian blackhead (n=20) and Charolaise (n=7). The first blood collection was conducted in April and the last one was performed in February. The highest level of Ca was estimated in Suffolk ewes, lowest (12.61%) in Merino breed; the highest Mg content was found in Lithuanian blackhead breed, lowest (5.26%) in Charolaise; highest P content was determined in Merino, lowest (24.18%) in Suffolk breed (p⟨0.05). Evalua-tion of the biochemical parameters during different seasons showed a possible environmental effect on the health of the animals. The difference among minerals content showed the highest level in Ca, Mg, Fe in the autumn, P - in the summer, Cu and Zn - in the winter. The lowest differences between seasons were observed in content of Mg (1.24-4.03% from total average of all seasons) and Ca (0.59-8.18%), the highest - in Cu (2.52-18.36 %) and Zn (4.33-24.33%) (p⟨0.05). The significance of this work is the possible use of the data in the prevention of metabolic and production diseases.

Functional product enriched with the microencapsulated extract of cupuassu (Theobroma grandiflorum Schum.) seed by-product

Abstract This work deals with the application of microencapsulated extract of cupuassu seed by-product to functionally enrich a food multimixture. The methodological bases applied were those of the Official Methods of Analysis of AOAC. Multimixture enrichment with the extract led to 54 and 19% increases in total dietary fiber and total fat contents, to slight decreases in carbohydrate and protein contents, while the total energy value was reduced by 6.4% due to the increase in unsaturated fatty acids content. The enriched multimixture showed a significant antioxidant activity and high levels of Ca2+, Fe2+, Zn2+ and ω-9 and ω-6 unsaturated fatty acids. Nutritional and functional qualities of this multimixture, as well as its excellent stability against progressive temperature increases frequently occurring in food preparations, suggest its use as a basic ingredient for food supplementation. The results also indicate excellent technological properties of the multimixture to formulate new food products.

Co-exposure of serum calcium, selenium and vanadium is nonlinearly associated with increased risk of type 2 diabetes mellitus in a Chinese population

BackgroundMetals play an important role in type 2 diabetes mellitus (T2DM). This study aimed to explore the association of T2DM risk with single metal exposure and multi-metal co-exposure. MethodsA case-control study with 223 T2DM patients and 302 controls was conducted. Serum concentrations of 19 metals were determined by inductively coupled plasma mass spectrometry (ICP-MS). Those metals with greater effects were screened out and co-exposure effects of metals were assessed by least absolute shrinkage and selection operator (LASSO) regression. ResultsSerum calcium (Ca), selenium (Se) and vanadium (V) were found with greater effects. Higher levels of Ca and Se were associated with increased T2DM risk (OR = 2.23, 95%CI: 1.38–3.62, Ptrend = 0.002; OR = 3.16, 95%CI: 1.82–5.50, Ptrend < 0.001), but higher V level was associated with decreased T2DM risk (OR = 0.58, 95%CI: 0.34–0.97, Ptrend < 0.001). Serum Ca and V concentrations were nonlinearly associated with T2DM risk (Poverall < 0.001, Pnonliearity < 0.001); however, Se concentration was linearly associated with T2DM risk (Poverall < 0.001, Pnonliearity = 0.389). High co-exposure score of serum Ca, Se and V was associated with increased T2DM risk (OR = 3.50, 95%CI: 2.08–5.89, Ptrend < 0.001) as a non-linear relationship (Poverall < 0.001, Pnonliearity = 0.003). ConclusionsThis study suggest that higher levels of serum Ca and Se were associated with increased T2DM risk, but higher serum V level was associated with decreased T2DM risk. Moreover, co-exposure of serum Ca, Se and V was nonlinearly associated with T2DM risk, and high co-exposure score was positively associated with T2DM risk.

Gα/GSA-1 works upstream of PKA/KIN-1 to regulate calcium signaling and contractility in the Caenorhabditis elegans spermatheca.

Correct regulation of cell contractility is critical for the function of many biological systems. The reproductive system of the hermaphroditic nematode C. elegans contains a contractile tube of myoepithelial cells known as the spermatheca, which stores sperm and is the site of oocyte fertilization. Regulated contraction of the spermatheca pushes the embryo into the uterus. Cell contractility in the spermatheca is dependent on actin and myosin and is regulated, in part, by Ca2+ signaling through the phospholipase PLC-1, which mediates Ca2+ release from the endoplasmic reticulum. Here, we describe a novel role for GSA-1/Gαs, and protein kinase A, composed of the catalytic subunit KIN-1/PKA-C and the regulatory subunit KIN-2/PKA-R, in the regulation of Ca2+ release and contractility in the C. elegans spermatheca. Without GSA-1/Gαs or KIN-1/PKA-C, Ca2+ is not released, and oocytes become trapped in the spermatheca. Conversely, when PKA is activated through either a gain of function allele in GSA-1 (GSA-1(GF)) or by depletion of KIN-2/PKA-R, the transit times and total numbers, although not frequencies, of Ca2+ pulses are increased, and Ca2+ propagates across the spermatheca even in the absence of oocyte entry. In the spermathecal-uterine valve, loss of GSA-1/Gαs or KIN-1/PKA-C results in sustained, high levels of Ca2+ and a loss of coordination between the spermathecal bag and sp-ut valve. Additionally, we show that depleting phosphodiesterase PDE-6 levels alters contractility and Ca2+ dynamics in the spermatheca, and that the GPB-1 and GPB-2 Gβ subunits play a central role in regulating spermathecal contractility and Ca2+ signaling. This work identifies a signaling network in which Ca2+ and cAMP pathways work together to coordinate spermathecal contractions for successful ovulations.

Highly selective and ultrafast removal of cadmium and copper from water by magnetic core-shell microsphere

Advanced treatment of heavy metals from various types of water is challenging but of great urgency due to their serious threat to water quality security. In this study, a new magnetic hybrid adsorbent with the core-shell structure, which is denoted as Fe3O4@SiO2@MO, was prepared by successively covering SiO2 and manganese oxide (MO) on Fe3O4. The covered SiO2 was designed to protect the magnetic core Fe3O4 from acid corrosion in practical application. The Fe3O4@SiO2@MO can be separated from solution within 10 s using an external magnetic field and very quickly remove Cd(II) and Cu(II) with equilibrium time below 10 min due to its special coating structure, which sharply reduces the diffusion distance of two metals before adsorption. Their effective coefficients of intraparticle diffusion (D) were determined to be 2.0 × 10−10 and 8.5 × 10−10 cm2 s−1. High levels of Ca(II) and Mg(II) inconspicuously affected the Cd(II) and Cu(II) retention onto Fe3O4@SiO2@MO, and only a decrease in removal below 20 and 12% for Cd(II) and Cu(II) occurred, respectively, due to the specific inner-sphere complexation between MO and the targeted metals. We preliminarily uncovered this interaction using XPS and FTIR analyses. Furthermore, in cyclic batch experiments, 1 kg Fe3O4@SiO2@MO can effectively treat 0.5 and 3.25 m3 of Cd(II)- and Cu(II)-contaminated wastewater to satisfy their corresponding discharge standards, respectively, which is equivalent to 500 and 3250 folds of its own weight. All results validate that Fe3O4@SiO2@MO is a promising engineered magnetic adsorbent to decontaminate heavy-metal-polluted wastewater.

Responses of Corpuscles of Stannius to intra-peritoneal vitamin-D3 administration in teleost Labeo rohita (Hamilton, 1822) reared in water with two different levels of calcium concentration.

This study assessed the responses of vitamin-D3 intraperitoneally injected to Rohu, Labeo rohita @ of 0 IU/kg bw (only solvent), 100 IU/kg bw and 500 IU/kg bw reared in 20 and 40 ppm of calcium (Ca) enriched water. The cellular changes in Corpuscles of Stannius (CS) gland, serum Ca, and inorganic phosphate (Pi) level were analysed up to the 60th day. Rohu administered with 100 IU/kg bw D3 and exposed to 40 ppm Ca-rich water exhibited notable hyperplasia of CS compared with their control groups. Notable changes with high serum Ca level (13.87 ± 0.3 mg/dl) was detected on the 5th day in fish exposed to 40 ppm Ca-rich water, while related values attained (13.74 ± 0.1 mg/dl) only after 7 days in 20 ppm Ca-rich water of 500 IU/kg bw vitamin D3 injection. Similarly, high serum Pi level (7.66 ± 0.2 mg/dl) in 40 ppm Ca injected with D3 at 500 IU/kg bw. The results demonstrated that the Ca homeostasis of Labeo rohita is influenced by intra-peritoneal vitamin D3. Progressive studies should be conducted by increasing the dose of vitamin D3 to investigate optimum dose/supplement in feed for commercially important aquaculture teleost Labeo rohita for maximum and sustainable absorption of Ca from the variable water Calcium levels to maintain Ca2+ homeostasis.

Product of Serum Calcium and Phosphorus (Ca x Pi) as a Predictor of Cardiovascular Disease Risk in Patients with Chronic Kidney Disease

INTRODUCTION: Most of the chronic kidney disease (CKD) patients develop cardiovascular disease (CVD) in their later stages. Various traditional CVD risk factors are highly prevalent in CKD but mortality of these patients cannot be fully justified by these CVD markers. So this study was designed to determine serum calcium and phosphorus product (Ca×Pi) to predict CVD risk in CKD patients.&#x0D; MATERIAL AND METHODS We followed the guidelines of NKF-KDOQI for CKD diagnosis and staging. Further the patients were classified into 3 different groups based on Ca×Pi product; &lt;40 mg2/dl2 (group 1), 40-55 mg2/dl2 (group 2) and &gt;55 mg2/dl2 (group 3). We then evaluated CVD risk by various traditional risk factors like age, BMI, BP, smoking history, dyslipidemia, previous history of CVD, LVH, arrhythmia, VHD, cardiomyopathy, and IHD.&#x0D; RESULTS: Higher level of Ca×Pi was associated with presence of LVH (32.30% in group 1, 31.42% in group 2 and 46.66% in group 3), Arrythemia (13.84% in group 1, 28.57% in group 2 and 46.67% in group 3), VHD (5.71% in group 2 and 10.00% in group 3), Cardiomyopathy (1.53% in group 1, 8.57% I group 2 and 6.66% in group 3), IHD (6.15% in group1, 11.42% in group 2 and 13.33% in group 3) and hypercholesterolemia, hypertriglyceridemia and increased LDLc.&#x0D; CONCLUSION: This study found that higher Ca×Pi increases with decline in glomerular filtration rate (GFR) and associated with CVD risks and CVD. So, this study raise a potential need to evaluate the level of calcium and phosphorus in all CKD patients and the level should be monitored more thoroughly to prevent CVD.

Efficacy of 1-α-Hydroxycholecalciferol Supplementation in Young Broiler Feed Suggests Reducing Calcium Levels at Grower Phase.

Increasing biopotency of cholecalciferol (D3) from vitamin sources is essential in the poultry industry to meet nutritional demands and counter stressors. D3 exhibits hormonal traits and is responsible for calcium (Ca) absorption. 1-α-Hydroxycholecalciferol (1α) is a synthetic form of D3 that has equal efficacy and is cheaper to synthesize than 1,25-dihydroxycholecalciferol (active form of D3), on broilers. However, 1α bypasses a critical regulatory point, the kidney, and may consequently lead to toxicity levels of Ca via Ca absorption. This study examined 1α supplementation in broiler diets with different Ca inclusion levels to determine if 1α at higher Ca levels caused Ca toxicity at starter and grower phases with Ross 708 male broiler chicks. In Experiment 1 (1–15 days of age), chicks were assigned to one of 10 treatment starter diets with five levels of Ca inclusion (0.80, 0.95, 1.10, 1.25, and 1.40%) with or without 1α supplementation (5 μg 1α/kg in feed) and eight replicate cages per treatment. In Experiment 2, chicks were fed common starter diet until 16 days of age, and then they were assigned to one of eight treatment diets with four levels of Ca inclusion (0.54, 0.76, 0.98, or 1.20%) with or without 1α supplementation (5 μg 1α/kg in feed). At the end of both experiments, blood was collected from broilers to determine blood chemistry, including concentrations of vitamin D metabolites. Intestinal tissues were also collected to examine gene expression. In Experiment 1, broilers not fed 1α exhibited a quadratic effect in ionized blood Ca (iCa) as dietary Ca inclusion levels increased; 1α-fed broilers displayed an increase in iCa as Ca inclusion levels increased (p = 0.0002). For Experiment 2, 1α-fed broilers displayed a decrease in 25-hydroxycholecalciferol plasma concentration as dietary Ca inclusion levels increased (p = 0.035); also, increasing Ca inclusion in diets increased expression of duodenal sodium phosphate cotransporter type II b (NPTIIb, p = 0.03). Our findings imply that inclusion of 1α was beneficial because 1α enhanced Ca absorption during the starter phase; however, to avoid potential Ca toxicity or antagonism while using 1α during the grower phase, there should be consideration with reducing dietary Ca levels.

Stimulatory effects of short-term calcitonin administration on plasma calcium, magnesium, phosphate, and glucose in juvenile Siberian sturgeon Acipenser baerii.

Calcitonin (CT) has a potential function in calcium (Ca) regulation, but there are conflicting observations in fishes. Because of the lack of calcified endoskeleton, sturgeons have low Ca circulating compared with teleost fish and the function of CT on Ca in sturgeon is very less understood. The purpose of this study was to investigate the impact of injection of salmon CT on plasma Ca, magnesium (Mg), phosphate (PHO), and glucose levels of juvenile Siberian sturgeon Acipenser baerii. Sixteen-month-old fish (429.6 ± 12.1g) were intraperitoneally injected with a single dose of CT (5μgkg-1 BW) and saline solution as a control group. Thereafter, blood sampling was performed at 0, 1, 2, 4, 6, 12, 24, and 48h after injection. CT produced marked increases in all variables measured. The highest levels of Ca (6.77 ± 0.53mgdL-1), Mg (9.79 ± 0.16mgdL-1) and PHO (1.74 ± 0.05mgdL-1) were recorded at 2h after CT injection and showed significant difference compared with control treatment (Ca 4.75 ± 0.12mgdL-1; Mg 5.47 ± 0.16mgdL-1 and PHO 1.23 ± 0.06mgdL-1). It also likely produced hyperglycemia. However, the differences with the controls were not statistically significant, possibly due to interference with the hyperglycemia induced by the stress of injection. Our results showed that the injection of 5μgkg-1 BW CT to Siberian sturgeon has an incremental effect on plasma Ca, Mg, and PHO. The increase in plasma Ca level indicated that CT has a potent hypercalcemic effect in sturgeon under laboratory condition, in contrast to the hypocalcemic effects reported for teleosts.

SUN-934 A Rare Case of Hyperparathyroidism - Parathyroid Carcinoma, Atypical Adenoma, or Both?

Introduction: Parathyroid carcinoma (PC) is a rare endocrine malignancy. It accounts for <1% cases of primary hyperparathyroidism (PHPT). We present a rare case of concurrent PC and atypical parathyroid adenoma (PA). Case presentation: A 72-year-old woman presented with 1-week history of generalized weakness, confusion, and auditory hallucinations. Her medical history was significant for PHPT known for 5 years, CAD and CHF. The patient appeared mildly volume depleted and was tachycardic (105/min). The rest of her physical exam was unremarkable. Calcium (Ca) was 15.1 mg/dL (8.4–10.2 mg/dL) and intact PTH 451.9 pg/mL (12–88 pg/mL). Her condition improved with aggressive fluid replacement, pamidronate, and cinacalcet. A sestamibi scan revealed increased uptake of bilateral parathyroid tissue. Fine needle aspiration (FNA) revealed PA. Surgical treatment was postponed for control of cardiac comorbidities. One month later, she presented again with symptomatic hypercalcemia. Her Ca was 16.1 md/dL and PTH 761.5 pg/mL. Initial medical management was followed by subtotal parathyroidectomy – three masses were removed (one on the right and two on the left). Final pathology revealed PC within the left parathyroid, the others were consistent with hypercellular parathyroid tissue. One month later, the patient underwent left hemithyroidectomy, right parathyroidectomy, and central neck dissection. PTH level dropped to 2.4 pg/mL and Ca level was 7.6 mg/dL after surgery. She was discharged home on Ca and vitamin D supplements. Pathology was sent to a referral cancer center and revealed PC vs. atypical PA within the right parathyroid. Discussion: PC is a rare endocrine malignancy. Further, there are not many cases of synchronous PC and PA or multifocal PC. Diagnosing PC preoperatively is challenging since it shares overlapping characteristics with PA. Patients with malignancy commonly present with larger tumor size, higher level of Ca (>14.6 mg/dL), and PTH (5-fold higher than the upper limit of normal). Our patient had a history of multiple admissions due to symptomatic HC. She had no palpable neck masses on exam. Her initial FNA was consistent with PA. Hence, we presumed that her hypercalcemia was caused by PA. Establishing a definitive diagnosis of PC by frozen sections intraoperatively is difficult. Histopathologic findings of atypical cells, high mitotic rate, and cellular invasions can suggest the diagnosis, though they are often negative. Even postoperatively, pathologists often disagree on cytologic interpretation. However, differentiating PA and PC is important since earlier and more aggressive treatment is needed to reduce the morbidity and mortality in case of malignancy.

Cycling phosphorus on the Archean Earth: Part II. Phosphorus limitation on primary production in Archean ecosystems

Several lines of evidence point to low rates of net primary production (NPP) in Archean oceans. However, whether Archean NPP was limited by electron donors or nutrients, particularly phosphorus (P), and how these factors might have changed over a billion years of recorded Archean history, remains contentious. One major challenge is to understand quantitatively the biogeochemical cycling of P on the early Earth. In Part I of this series (Hao et al., 2020), we estimated the weathering flux of P to the oceans as a function of temporally increasing continental emergence and elevation through Archean time. In Part II, we conduct thermodynamic and kinetic simulations to understand key processes of P cycling within the Archean ocean, including seafloor weathering, recycling of organic P, the solubility and precipitation of secondary phosphate minerals, and the burial diagenesis of P precipitates. Our calculations suggest low solubilities of apatite minerals in Archean seawater, primarily due to nearly neutral pH and high levels of Ca. This low solubility, in turn, implies a negligible contribution of apatite dissolution to P bioavailability in Archean seawater.We also simulate the solubility limits of common secondary P-bearing minerals, showing that vivianite would have been the least soluble P mineral in ferruginous Archean seawater (0.1–0.3 µM), even at moderate supersaturation states (Ω = 100 or 1000). If vivianite precipitation was kinetically favorable by microbial activities and mineral adsorption, the sinking flux of P as vivianite in Archean seawater could have reached the modern sinking flux, implying that vivianite precipitation was a potentially major sink for P in Archean oceans. During burial diagenesis, however, vivianite in porewater would have become less stable than Ca-phosphates of lower solubility. At elevated temperatures (>100 °C) associated with burial diagenesis and low-grade metamorphism, vivianite is predicted to react irreversibly with calcite to form apatite.Optimistic assumptions about the recycling efficiency of P on the Archean Earth lead us to estimate that by the end of the eon the total flux of P (continental weathering + recycling) could have supported NPP at levels up to 7% of the modern. The total flux of P would have been much lower on the early and middle Archean Earth, whereas fluxes of electron donors could have been higher, suggesting very low productivity and P-limitation of marine ecosystems during much of the eon. Comparing our estimates of NPP as limited by P supply with the estimate by Ward et al. (2019), in which NPP was limited by electron donors and metabolic efficiency, there could have been a transition between P-limited productivity in the early to middle Archean to electron donor-limitation closer to the eon’s end (assuming no oxygenic photosynthesis). Once oxygenic photosynthesis reached ecological significance, probably near the end of the Archean, our estimated flux of P would allow rapid oxidation of atmosphere.

Massive Ascites of Unknown Origin: A Case Report

Ascites is the excessive accumulation of fluid in the peritoneal cavity and predominantly caused by liver cirrhosis, cancers, or heart failure. In this study, a 31-year-old woman with chronic renal failure of unknown etiology treated with hemodialysis and peritoneal dialysis was often hospitalized because of ascites, which appeared 4 years after the second kidney transplantation. The patient was regularly (every 2-3 weeks) treated with paracentesis. Peritoneal fluid tested negative for bacterial (including atypical) and fungal infections and tuberculosis. Doppler ultrasound and liver FibroScan did not show any irregularities. Computed tomography (CT) revealed an enlarged left ovary. A high level of CA 125 was found. The second diagnostic laparoscopy revealed no changes in the ovaries, and there were no tumor cells. Diagnostics were extended, but no deviations were revealed. Suspecting drug etiology, mycophenolic acid was discontinued, bringing no improvement. Diagnostic tests caused suspicion of Meigs’ syndrome; therefore, oophorectomy of left ovary was conducted, revealing numerous small cysts filled with serous fluid, without tumor cells in the ovary or peritoneal fluid. Despite the procedure performed, ascites was recurrent. Five month later, ascites spontaneously stopped growing. Paracentesis to decompress ascites was no longer required. There were 9 paracenteses performed from oophorectomy (the latest on May 23, 2019). The need for repetitive paracentesis, significantly reducing the patient’s quality of life, required diagnosis for casuistic diseases. The described case is atypical because of the confusing etiology of ascites and its spontaneous cessation. Despite numerous examinations and recession of ascites, the cause of the problem is not entirely clear.

Effect of alkaline pretreatment on photo-fermentative hydrogen production from giant reed: Comparison of NaOH and Ca(OH)2

Giant reed was the first time used for photo-fermentative hydrogen production with HAU-M1 bacteria. Effects of NaOH and Ca(OH)2 pretreatments of giant reed on structural changes, enzymatic digestibility, hydrogen production, and energy conversion efficiency were evaluated. Compared to Ca(OH)2 pretreatment, NaOH pretreatment removed more dry matter and lignin at the same loading. The highest glucose yield (44.9%) of NaOH pretreatment was 1.74-fold higher than that of Ca(OH)2 pretreatment. 20% NaOH pretreated giant reed biomass achieved the highest hydrogen yield (98.3 mL/g TS), which was 20% and 70% higher than the highest level of Ca(OH)2 pretreated (20% Ca(OH)2) and untreated giant reed, respectively. Only giant reed biomass pretreated with 20% NaOH resulted in a significant (p < 0.05) increase (25%) in energy conversion efficiency.