Low Calcium Concentrations Research Articles

Role of Impaired Oxalate Homeostasis in Cardiovascular Disease in Patients With End-Stage Renal Disease: An Opinion Article.

Role of Impaired Oxalate Homeostasis in Cardiovascular Disease in Patients With End-Stage Renal Disease: An Opinion Article.

Reducing the Waiting-On-Cement Time of Geopolymer Well Cement using Calcium Chloride (CaCl2) as the Accelerator: Analysis of the Compressive Strength and Acoustic Impedance for Well Logging

Geopolymer cement (GPC) is an aluminosilicate-based binder that is cost-effective and eco-friendly, with high compressive strength and resistance to acid attack. It can prevent degradation when exposed to carbon dioxide by virtue of the low calcium content of the aluminosilicate source. The effect of the concentration of calcium chloride (CaCl2) as the accelerator on the compressive strength and acoustic impedance of GPC for well cement, while exposed to high pressure and high temperatures, is presented. Fly ash from the Tanjung Bin power plant, which is categorized as Class F fly ash according to ASTM C618-19, was selected as the aluminosilicate source for the GPC samples. Sodium hydroxide and sodium silicate were employed to activate the geopolymerization reaction of the aluminosilicate. Five samples with a density of 15 ppg were prepared with concentrations of CaCl2 that varied from 1% to 4% by weight of cement. Findings revealed that the addition of 1% CaCl2 is the optimum concentration for the curing conditions of 100 °C and 3000 psi for 48 h, which resulted in the highest compressive strength of the product. Results also indicate that GPC samples that contain CaCl2 have a smaller range of acoustic impedance compared to that of ordinary Portland cement.

Modelling the spatial distribution of mycetoma in Sudan.

BackgroundMycetoma is a neglected tropical disease that is reported worldwide and Sudan has the highest reported number of mycetoma infections across the globe. The incidence, prevalence and burden of mycetoma globally are not precisely known and its risk factors remain largely unelucidated.MethodsThis study aimed to identify the environmental predictors of fungal and bacterial mycetoma in Sudan and to identify areas of the country where these niche predictors are met. Demographic and clinical data from confirmed mycetoma patients seen at the Mycetoma Research Centre from 1991 to 2018 were included in this study. Regression and machine learning techniques were used to model the relationships between mycetoma occurrence in Sudan and environmental predictors.ResultsThe strongest predictors of mycetoma occurrence were aridity, proximity to water, low soil calcium and sodium concentrations and the distribution of various species of thorny trees. The models predicted the occurrence of eumycetoma and actinomycetoma in the central and southeastern states of Sudan and along the Nile river valley and its tributaries.ConclusionOur results showed that the risk of mycetoma in Sudan varies geographically and is linked to identifiable environmental risk factors. Suitability maps are intended to guide health authorities, academic institutes and organisations involved in planning national scale surveys for early case detection and management, leading to better patient treatment, prevention and control of mycetoma.

Fresh and hardened properties of alkali-activated fly ash/slag binders: effect of fly ash source, surface area, and additives

The variation of the raw materials is critical for the wide application of alkali-activated fly ash/slag (AAFS) in practice. In this study, four fly ashes sourced from different power plants were collected and analyzed. The calcium content in fly ash had insignificant impact on setting time, flowability and compressive strength of AAFS binders when the slag content was 50%. Low calcium content in fly ash promotes the formation of C-(N)A-S-H gel with high Al substitution and improves the compressive strength at later age. It seemed that the grinding process promoted the dissolution of reactive SiO2 in fly ash, resulting in reduced setting and flowability. The replacement of silica fume promotes the formation of Si-rich C-(N)A-S-H gel with reduced gel pore size. The replacement of metakaolin accelerated the initial reaction and increased the compressive strength of binders at early age due to the reduced gel pore size in C-(N)A-S-H gel.

Cytoprotective effects of spirulina extract against doxorubicin‐induced cardiotoxicity: Biochemical evidences and translational perspectives in cardio-oncology.

e15042 Background: Spirulina, a blue-green algae used in the daily diet of natives of Africa and America, has antioxidant, anticancer, antiviral, hepatoprotective, immune enhancing and lipid-lowering effects. Considering that doxorubicin-induced cardiotoxicity involves myocardial inflammation, ferroptosis and overexpression of several cytokines involved in cell dead and apoptosis, the use of spirulina during exposure to doxorubicin could be an intriguing method to reduces myocardial injuries in cancer patients undergoing treatment with anthracyclines. Methods: Human fetal cardiomyocytes (HFC cell line) were exposed to doxorubicin (from 10 to 500 nM), alone or in combination with spirulina extract (from 10 to 100 µg/ml) for 24 and 48h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). Results: Spirulina extract, co-incubated with doxorubicin exerts cardioprotective effects, enhancing cell viability of 20-36.7 % compared to untreated cells (p<0,01 for all); spirulina extract reduced significantly the cardiotoxicity through MyD88/NF-KB/cytokines axis and mTORC1 Fox01/3α mediated mechanisms and reduces oxidative damages of doxorubicin resulting in lower intracellular calcium content. Conclusions: For the first time, it was demonstrated that spirulina extract exert anti-inflammatory and cytoprotective properties in myocardial cells exposed to growing concentration of doxorubicin leading to preclinical studies in mice analyzing any effects on cardiac strain and left ventricular ejection function.

Incidence, clinical patterns, and risk factors of postpartum uterine diseases in dairy cows from high-altitude tropical herds

The cow's uterus sustains bacterial contamination and active inflammation after calving as part of the normal physiological process of uterine involution. Although the definition, incidence, and risk factors for postpartum uterine diseases (PUD) have been documented in annual calving systems with high-producing cows on total mixed ration, the literature contains little information for other production systems. The objective of this study was to quantify the incidence risk and factors associated with metritis, clinical endometritis, and cytological endometritis in high-altitude tropical dairy herds in a pasture-based system. A total of 248 cows from 5 commercial dairy herds in northern Antioquia, Colombia, were enrolled in this prospective observational longitudinal cohort study. Data collection and PUD diagnosis were performed at d 0, 3, 10, 17, 24, 31, 38, 45, and 52 (±1) after parturition. Between 60 and 70 d, cows were systematically enrolled in a synchronization protocol, and herds were visited monthly for pregnancy diagnosis until 180 ±15 d. The multivariable logistic regression model of variables associated with PUD occurrence included (a) parity, season of calving, transition diet, and body condition score at calving; (b) blood calcium, phosphorus, and magnesium concentrations, and milk urea nitrogen, β-hydroxybutyrate and fat-to-protein ratio; and (c) dystocia, retained placenta, and delayed uterine involution. The incidences of puerperal metritis, clinical metritis (MET), clinical endometritis (CE), and cytological endometritis (CYTO) were 2.8, 25, 29, and 26%, respectively. Retained placenta and dystocia were associated with MET, and MET was associated with CE. Low blood calcium concentration at calving was associated with CYTO. Overall, 51.2% of the cows suffered at least 1 category of PUD during the first 60 d postpartum (DPP). However, cows also suffered from different consecutive clinical events of PUD (MET, CE, and CYTO) during the follow-up period (0 to 180 ±15 DPP). These events could be grouped into 4 types (which were referred to as "clinical patterns") based on interactions between MET, CE, and CYTO.

Effect of citric-acid dialysate on the QTC-interval

Lower dialysate calcium (dCa) concentration and dialysate citric-acidification may positively affect calcification propensity in serum of haemodialysis (HD) patients. However, the accompanying lower ionized blood calcium concentration may lead to a prolonged cardiac action potential, which is possibly pro-arrhythmic. The aim of this study is to investigate the influence of citric-acid dialysate on the QT-interval corrected for heart rate (QTc) compared to conventional dialysate with different dCa concentrations. We conducted a four-week multicentre, randomized cross-over trial. In week one and three patients received acetic-acid dialysate with a dCa of 1.50 mmol/l (A1.5), in week two and four acetic-acid dialysate with a dCa of 1.25 mmol/l (A1.25) or citric-acid dialysate (1.0 mmol/l) with a dCa of 1.50 mmol/l (C1.5) depending on randomization. Patients had continuous ECG monitoring during one session in week one, two and four. The data of 13 patients were available for analysis. Results showed a significant though limited increase of QTc with C1.5 (from 427 to 444 ms (start to end); p = 0.007) and with A1.25 (from 431 to 449 ms; p < 0.001), but not with A1.5 (from 439 to 443 ms; p = 0.13). In conclusion, we found that the use of C1.5 or A1.25 is associated with a significant prolongation of QTc which was however relatively limited.

Aquatic and terrestrial proxy evidence for Middle Pleistocene palaeolake and lake‐shore development at two Lower Palaeolithic sites of Schöningen, Germany

The archaeological sites in the open‐cast mine of Schöningen, Germany, represent outstanding archives for understanding Middle Pleistocene interglacial–glacial transitions and human adaption. Aquatic microfossil and pollen assemblages from the ‘Reinsdorf sequence’, likely correlated to Marine Isotope Stage 9, document environmental changes from a thermal maximum to succeeding glacial conditions recorded in two sequences of excavation sites 12 II and 13 II. Multi‐proxy analyses enable detailed reconstruction of lake‐shore and landscape developments despite variable microfossil preservation in changing carbonate‐ and organic‐rich deposits. Rich aquatic vegetation with abundant charophytes suggests repeated phases with water depths of 0.5–2 m at site 13 II, while even greater temporary depths are deduced for 12 II DB. Mesorheophilic and mesotitanophilic ostracod species indicate stream inflows with medium–low calcium contents of &gt;18 mg Ca L–1 originating from nearby springs. Diatoms point to meso‐eutrophic conditions and an alkaline pH of the lake water. Interglacial conditions with thermophile forests but no aquatic microfossils preserved, suggesting a dry or only temporarily flooded site, mark the beginning of the sequence. Continuous presence of aquatic organisms and overall dominance of small tychoplanktonic diatoms during a subsequent cool steppe phase provide evidence for increased water depths and unstable habitats characterized by erosion and probably prolonged periods of lake ice cover. During the succeeding boreal forest‐steppe phase, surface runoff into the productive, shallow lake decreased due to a more extensive vegetation cover. Concurrently, intensified groundwater input in contact with the nearby salt wall caused elevated salinities. Following a lake level drop, stream inflows and lake levels increased again towards the end of the Reinsdorf sequence and promoted development of a diverse fauna and flora at the lake shore; thereby maintaining an attractive living and hunting environment for early humans during a phase of generally cooler temperatures and landscape instability at the transition into a glacial period.

Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers

The main object of this study is to investigate the geopolymerization potential of recycled waste concrete powder (RWCP) as well as the effects of synthesis parameters, including the molarity of NaOH solution, the mass ratio of water glass to NaOH solution (WG/NH), the mass ratio of liquid alkali activator to solid powder (L/S), and the curing conditions (curing temperature, curing time and curing method), on the development of unconfined compressive strength (UCS) of recycled waste concrete powder-based geopolymers. The recycled waste concrete powder (RWCP) (size < 0.075 mm) was utilized as source material, and water glass and sodium hydroxide (NaOH) were used as alkaline activators to synthesize geopolymer specimens. The dissolution of alumino-silicate from the RWCP under different concentrations of alkaline solutions was studied. The UCS of the resulting geopolymers synthesized under different conditions was tested. Further, the microstructure and mineral composition of the final products were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) technology. The results indicate that the dissolution of Si4+ and Al3+ in raw materials (RWCP) was highly affected by the alkali content and dissolution time. Increasing the alkali content, water glass content and L/S ratio was all conducive to enhancing the UCS of geopolymers. The optimum NaOH concentration corresponpded to 14 mol/L, WG/NH ratio of 1.5 and L/S mass ratio of 0.4. A maximum 7-day UCS of 14.32 MPa was achieved by wet curing at 70 ℃ for 24 hours. Microscopic analysis showed that the final products were mainly composed of amorphous hydrated calcium silicate and hydrated sodium aluminosilicate gels. However, due to the low activity and high calcium content of RWCP, most of crystalline phases and some unreacted substances still existed in the end products as inactive fillers, resulting in a relatively low UCS of the synthesized geopolymers. Baded on the research, it can be concluded that RWCP can be recycled as the precursor to synthesize geopolymer binder.

Effect of oral calcium administration on metabolic status and uterine health of dairy cows with reduced postpartum rumination and eating time

BackgroundHypocalcemia has detrimental effects on health and performance of dairy cows. As hypocalcemic cows show reduced feed intake, we hypothesized that cows with reduced combined rumination and eating time (CRET) may benefit from Ca supplementation. The objective was to evaluate the effect of postpartum oral Ca administration on metabolic status (Calcium [Ca], fatty acids [FA], and β-Hydroxybutyrate [BHB] serum concentrations) and incidence of puerperal metritis (PM) in dairy cows with reduced postpartum CRET. Cows in an organic-certified dairy, diagnosed with reduced CRET (< 489 min/d; n = 88) during the first day postpartum were assigned into 1 of 2 treatments: i) Calcium administration (CA; n = 45) that received 1 Ca oral capsule (Bovikalc bolus, Boehringer Ingelheim, St. Joseph, MO) containing CaCl2 and CaSO4 (43 g of Ca) once per day, for 3 consecutive days, starting at d 1 postpartum; and ii) Control (CON; n = 43) that did not receive oral Ca. A convenience group consisting of cows with CRET ≥489 min/d was used for comparison and did not receive oral Ca (NOR; n = 96).ResultsAt day 1 postpartum cows with reduced CRET had lower Ca serum concentrations (CA = 2.08 mmol/L; CON = 2.06 mmol/L) compared with NOR cows (2.17 mmol/L). Calcium concentrations at d 3, 5, and 12 postpartum were not different among the three groups. Serum FA concentrations at d 1, 3 and 5 postpartum were higher in both CA and CON cows compared with NOR. At d 12, only CA cows had higher FA concentrations than NOR cows. Serum BHB concentrations at d 3 were highest in CA, with no difference between CON and NOR. At d 5, BHB concentrations were higher in CA, followed by CON, and NOR. No effect was observed for Ca administration on incidence of PM and reproductive performance. CON cows had lower survival at 30 DIM (86.5%) than NOR cows (97.9%).ConclusionsThe use of remote sensor technology identified cows with reduced rumination and eating time that had lower postpartum serum concentrations of calcium and altered metabolic status. However, oral calcium administration to cows with reduced CRET did not affect incidence of metabolic disorders nor reproductive health and subsequent pregnancy. Although survival at 30 days postpartum was lower for non-Ca supplemented cows, the identification of effective interventions in cows with reduced CRET requires further consideration.

Preparation of bioactive glass nanoparticles with highly and evenly doped calcium ions by reactive flash nanoprecipitation

Nanoscale bioactive glass particles have greater bioactivity than microscale bioactive glass particles, due to their high-specific surface area and fast ion release rate in body fluid. However, preparation of bioactive glass nanoparticles (BGNPs) is difficult since calcium is not easy to be highly doped into the forming silica atom network, leading to an uneven distribution and a low content of calcium. In addition, BGNPs are usually prepared in a dilute solution to avoid agglomeration of the nanoparticles, which decreases the production efficiency and increases the cost. In this work, BGNPs are prepared by a method of the reactive flash nanoprecipitation (RFNP) as well as a traditional sol–gel method. The results indicate that the BGNPs by the RFNP present a smaller size, narrower size distribution, more uniform composition, and better bioactivity than those by the traditional sol–gel method. The obtained BGNPs have uniform compositions close to the feed values. The high and even doping of calcium in the BGNPs is achieved. This successful doping of calcium into nanoparticles by the RFNP demonstrates a promising way to effectively generate high-quality BGNPs for bone repairs.

Ionic flux and geological release of fluoride in groundwater sources of a semi-arid tropical region in south India

ABSTRACT Groundwater with excess fluoride content is a major issue in most of the states in India. Mineral ions and its seasonal fluctuations are influencing fluoride contamination in groundwater sources to a greater extent. Reports on health issues from several regions of south India have instigated detailed studies on groundwater fluoride contamination and the geo-environmental reasons underlying it. Fluoride contamination in the groundwater sources of Palakkad district, a semi-arid tropical region in South India, was assessed along with major anions and cations. The study revealed that 89% of Po, 88% of Pr, and 52% of Mo samples exceeded the BIS limit of fluoride concentration of 1.0 mg/L. The piper plot and correlation studies affirm that fluoride contamination is accelerated by a higher concentration of magnesium, sodium ions and a lower concentration of calcium and dissolved iron. The negative correlation of fluoride with nitrates supports its geological origin. Fluoride contamination is highly linked with the hornblende biotite gneiss (~ 42%) distributed in the central-eastern part of the district. IDW interpolation defines a maximum of 3.4 mg/L of fluoride in the groundwater sources. The overdose of fluoride in drinking water, which exceeded the OFC level, is noted to be the reason for the prevalence of fluorosis in the study area. The study recommends 0.61 mg/L of fluoride as an OFC limit for drinking purposes.

Single-cell visualization and quantification of trace metals in Chlamydomonas lysosome-related organelles

The acidocalcisome is an acidic organelle in the cytosol of eukaryotes, defined by its low pH and high calcium and polyphosphate content. It is visualized as an electron-dense object by transmission electron microscopy (TEM) or described with mass spectrometry (MS)-based imaging techniques or multimodal X-ray fluorescence microscopy (XFM) based on its unique elemental composition. Compared with MS-based imaging techniques, XFM offers the additional advantage of absolute quantification of trace metal content, since sectioning of the cell is not required and metabolic states can be preserved rapidly by either vitrification or chemical fixation. We employed XFM in Chlamydomonas reinhardtii to determine single-cell and organelle trace metal quotas within algal cells in situations of trace metal overaccumulation (Fe and Cu). We found up to 70% of the cellular Cu and 80% of Fe sequestered in acidocalcisomes in these conditions and identified two distinct populations of acidocalcisomes, defined by their unique trace elemental makeup. We utilized the vtc1 mutant, defective in polyphosphate synthesis and failing to accumulate Ca, to show that Fe sequestration is not dependent on either. Finally, quantitation of the Fe and Cu contents of individual cells and compartments via XFM, over a range of cellular metal quotas created by nutritional and genetic perturbations, indicated excellent correlation with bulk data from corresponding cell cultures, establishing a framework to distinguish the nutritional status of single cells.

Calcium in the mineral nutrition of yellow passion fruit cultivated in lined pits and with saline water

ABSTRACT Nutritional status is an important tool in salinity management, because salt stress interferes with both the absorption and the assimilation of mineral nutrients by plants. The objectives of this experiment were to evaluate the effects of water salinity, lateral protection of pits against water losses and calcium doses on the leaf concentration of macronutrients and sodium of yellow passion fruit cv. BRS GA1. The treatments were arranged in a randomized block design in split plots in a 2 × (2 × 5) factorial scheme, corresponding to water salinity (0.3 and 4.0 dS m-1) in the main plot, and the combinations between lateral protection of pits (without and with) and calcium doses (0, 30, 60, 90 and 120 kg ha-1) in the subplots. Leaf concentrations of macronutrients and sodium were determined at the phenological stage of full flowering. Irrigation of yellow passion fruit with 4.0 dS m-1 water decreased the leaf concentrations of macronutrients. The lining of the pits compromised macronutrient concentration in the plants. Calcium fertilization is recommended for yellow passion fruit cultivated in Entisol with low calcium concentration at the dose of 60 kg ha-1, because it raises nitrogen and calcium concentrations in plants irrigated with non-saline water and magnesium and sulfur concentrations in those irrigated with saline water. Calcium attenuates salt stress because it promotes the accumulation of macronutrients in yellow passion fruit under saline conditions.

Bond strength of a universal adhesive system to bovine vs. human primary teeth

To compare the bond strength of a universal adhesive system to bovine primary and human primary enamel and dentin. Flat enamel and dentin surfaces from 28 sound human primary molars and 28 bovine primary incisors were bonded with Scotchbond Universal Adhesive applied in etch-and-rinse and self-etch mode (n = 7). Composite resin cylinders (0.72 mm 2 ) were built on the adhesive area. The specimens were submitted to a microshear bond strength test, and the bond failure mode was evaluated. Bond strength data (MPa) were analyzed using two-way ANOVA and Tukey's test (α = 0.05). Energy-dispersive X-ray spectroscopy (EDS) was carried out to identify the levels of calcium and phosphorus in each type of teeth. Higher bond strength values were found to bovine primary enamel compared to human enamel (p = 0.04). No statistically significant differences were found between bovine and human primary dentin (p = 0.09). The universal adhesive applied in self-etch mode to enamel resulted in lower bond strength values (p < 0.05). EDS analysis showed significantly lower calcium content in bovine primary dentin (p = 0.01), but no significant differences were found between bovine and human primary enamel. Bovine primary teeth can only reliably replace human teeth in bonding studies when dentine is the focused substrate. Bovine primary enamel promotes higher bond strength values compared to human primary enamel.

Features of dental status in senior schoolchildren depending on mineral composition of drinking water

Objective. Hygienic assessment of the quality of drinking water from two rivers, Kama and Chusovaya, which supply the city of Perm, was carried out. Water in them is different in mineral composition, but similar in terms of anthropogenic pollution.&#x0D; Materials and methods. Dental status was determined in 142 schoolchildren aged 15-17 years old, who use water from different sources. The concentration of total calcium and magnesium in the oral fluid was determined for all schoolchildren.&#x0D; Results. The study found that the degree of mineralization of drinking water affects the mineral composition of the saliva. Schoolchildren, who use drinking water of low mineralization, have a low concentration of calcium and magnesium in the saliva and a high intensity of dental caries. Schoolchildren, who use drinking water of increased mineralization, have a high concentration of calcium and magnesium in the saliva, a low intensity of dental caries and a high intensity of periodontal diseases due to an increased formation of tartar. Treatment and preventive measures, carried out among schoolchildren, included the drug Complivit, plates CM 1, low-intensity laser light.&#x0D; Conclusions. The effectiveness of treatment and preventive measures was determined by the activity of the oral fluid enzymes before and after the course of treatment.

Polypyrrole-BaFe2O4 sensing layer for detection of strontium ion in aqueous solution using surface plasmon resonance curves fitting

The low concentration of strontium, calcium, and barium were measured with a surface plasmon resonance curve fitting technique. Polypyrrole-BaFe2O4 nanocomposite was prepared using electro-polymerization of pyrrole in the presence of magnetic nanoparticles. The thickness of the layer in the range of 6.3 and 62.2 nm the analytical methods such as Fourier transform infrared spectroscopy, energy dispersive spectroscopy, and field emission scanning electron microscopy authenticated the polypyrrole-BaFe2O4 nanocomposite formed on the surface of the gold layer. The prepared layers were used to detect and measure the low concentration of strontium, calcium, and barium ions in aqueous solution using surface plasmon resonance technique and the optical parameter, angle of resonance, resonance angle shift and affinity constant were achieved using curve fitting based on minimizing the sum of squared errors. Consequently, the degree of adsorption for the detection of strontium is about 91.3%, and the sensitivity of the polypyrrole-BaFe2O4 nanocomposite layer for the detection of strontium is about 0.006° that is more than other ions.

Impacts of Iron Metabolism Dysregulation on Alzheimer's Disease.

Iron plays an important role in maintaining cell survival, with normal iron trafficking known to be regulated by the ceruloplasmin-transferrin (Cp-Tf) antioxidant system. Disruption to this system is thought to be detrimental to normal brain function. To determine whether an imbalance of iron and the proteins involved in its metabolism (ceruloplasmin and transferrin) are linked to Alzheimer's disease (AD) and to the expression of amyloid-beta (Aβ) peptide 1-42 (Aβ1-42), which is a major species of Aβ, and the most toxic. We evaluated the concentrations of iron, calcium, magnesium, and Aβ1-42 in the cerebrospinal fluid (CSF) of patients with AD and cognitively normal controls. Correlations between the components of the Cp-Tf antioxidant system in plasma were studied to determine the role of peripheral blood in the onset and/or development of AD. We used commercial ELISA immunoassays to measure Aβ1-42, immunoturbidimetry to quantify ceruloplasmin and transferrin, and colorimetry to quantify iron, calcium, and magnesium. We found that the AD group had lower CSF concentrations of Aβ1-42 (p < 0.001) and calcium (p < 0.001), but a higher CSF concentration of iron (p < 0.001). Significantly lower plasma concentrations of ceruloplasmin (p = 0.003), transferrin (mean, p < 0.001), and iron (p < 0.001) were observed in the AD group than in cognitively normal adults. Moreover, we found a strong interdependence between most of these components. Iron dyshomeostasis has a crucial role in the onset of AD and/or its development. Correcting metal misdistribution is an appealing therapeutic strategy for AD.

Effect of rosR Gene Overexpression on Biofilm Formation by Rhizobium leguminosarum

The regulatory protein encoded by the rosR gene is involved in the processes of adaptation of root nodule bacteria Rhizobium leguminosarum to changes in environmental conditions. It affects the expression of a number of genes associated with the synthesis of exopolysaccharides, which play a critical role in formation of bacterial biofilms on various surfaces. The goal of this work was to study the effect of overexpression of the rosR gene on formation of R. leguminosarum biofilms on inert surfaces and roots of heterologous plant hosts by obtaining recombinant strains with an additional copy of the rosR gene under the control of the Pm promoter. Our analysis of recombinant strains showed that additional expressed copies of the rosR gene allowed rhizobia to overcome the inhibitory effect on biofilm formation caused by low calcium concentrations in the medium, the effect of proteases and detergents, and to form biofilms more efficiently on the surface of tomato and clover roots. The results obtained open up prospects for using rosR as a tool both for increasing the efficiency of endosymbiosis of rhizobia with legumes, and for the formation of stable associative interactions with other agricultural crops.

Comparison of blood biochemical parameters of stallions of different age groups

The analysis of biochemical parameters of blood serum of stallions of different age groups (n = 86) is carried out. It was found that with age there is an increase in the concentration of total protein, fibrinogen, direct and indirect bilirubin, while the group of young stallions aged 3-5 years is characterized by a higher value of alkaline phosphatase activity compared to the group of 6-10 years (p = 0.002) and a lower value calcium concentration compared with the group of stallions aged 16-22 years (p = 0.012).