Decrease In Magnesium Concentration Research Articles

Investigation of Adiponectin, Leptin and Ghrelin Levels and Evaluation of Metabolic Profiles in the Periparturient Period in Romanov Sheep

The periparturient period is very important especially in terms of pregnancy-related herd-based diseases. In this period, especially for early diagnosis of subclinical diseases, a metabolic profile test is used. In the periparturient period, important changes occur in adipose tissue. Blood samples were collected from 16 Romanov sheep in the periparturient in serum tubes on the 21st, 14th, 7th, and postpartum days, and 7th, 14th, and 21st days after delivery. Metabolic profile and Adiponectin, Leptin and Ghrelin parameters evaluated from the blood samples. In the periparturient period, ELISA analyzes of TNF-α were performed for inflammatory evaluation. As a result of the analyzes, Prenatal increase in NEFA concentrations, postpartum decrease in cholesterol concentrations, postpartum increase and decrease in AST concentrations, postpartum increase in GGT concentrations, prenatal and postnatal increases in total protein concentrations, postpartum increase in BUN and creatinine concentrations, postpartum decrease in magnesium concentrations, Prenatal increase in adiponectin concentrations and postpartum decrease, postpartum decrease in leptin concentrations and prenatal increase in ghrelin concentrations occurred. With the results obtained, it was concluded that the evaluation of metabolic profile and adipose tissue is important in the diagnosis of diseases in the periparturient period.

Assessment of subclinical magnesium deficiency in pregnant women

Introduction. The question of the ratio of calcium and magnesium in the body in the scientific community is not discussed as often as the role of each of these elements. Experts pay even less attention to the ratio of minerals in the body of pregnant women.Aim. To analyze the content of magnesium and calcium in the blood of pregnant women at different gestation periods and evaluate the ratio of magnesium / calcium in order to establish the calculated coefficient.Materials and methods. 272 pregnant women (age 31.85 ± 5.0 years) at different gestation periods were included in the study. The subjects did not complain, typical for the clinic of magnesium and calcium deficiency. All surveyed gave written consent to the study. A biochemical blood test (determination of the concentration of total calcium, magnesium) was carried out in the laboratory of LLC DNKOM in Moscow. Blood sampling from the cubital vein was carried out according to the standard method in the morning on an empty stomach after 10–12 hours of fasting.Results and discussion. Concentration of total calcium in the serum was (M ± SD) 2.28 ± 0.11 mmol/l, total magnesium – 0.78 ± 0.07 mmol/l, magnesium/calcium ratio – 0.34 ± 0.03. Mean concentrations of calcium and magnesium were significantly lower in women in the II and III trimesters compared with the I trimester (p < 0.001). A decrease in magnesium concentration below the optimal for pregnant women of 0.8 mmol / l was observed in 37.5% of women in the first trimester, in 77.3% and 84.1% in the II and III trimesters, respectively. Serum magnesium concentration less than 0.7 mmol / l, reflecting a profound magnesium deficiency, was detected in the first trimester in 3.6% of women, in the second trimester – in 11.3% of women, in the third trimester – in 15.9% of pregnancies. Hypocalcemia (total calcium concentration less than 2.15 mmol/l) was recorded in 0.9%, 11.3% and 22.3% of pregnant women in the I, II and III trimesters. When calculating the magnesium/calcium ratio, subclinical magnesium deficiency was detected in 96.7% of pregnant women throughout pregnancy. Conclusion. The data obtained indicate the need for pregravid examination and early correction of metabolic disorders.>< 0.001). A decrease in magnesium concentration below the optimal for pregnant women of 0.8 mmol / l was observed in 37.5% of women in the first trimester, in 77.3% and 84.1% in the II and III trimesters, respectively. Serum magnesium concentration less than 0.7 mmol / l, reflecting a profound magnesium deficiency, was detected in the first trimester in 3.6% of women, in the second trimester – in 11.3% of women, in the third trimester – in 15.9% of pregnancies. Hypocalcemia (total calcium concentration less than 2.15 mmol/l) was recorded in 0.9%, 11.3% and 22.3% of pregnant women in the I, II and III trimesters. When calculating the magnesium/calcium ratio, subclinical magnesium deficiency was detected in 96.7% of pregnant women throughout pregnancy.Conclusion. The data obtained indicate the need for pregravid examination and early correction of metabolic disorders

Investigation of degraded bone substitutes made of magnesium alloy using scanning electron microscope and nanoindentation

Degradable bone substitutes made of magnesium alloys are an alternative to biological bone grafts. The main advantage is that they can be manufactured location- and patient-specific. To develop and scale appropriate implants using computational models, knowledge about the mechanical properties and especially the change in the properties during the degradation process is essential. Therefore, degraded open-pored implants were investigated using scanning electron microscope and nanoindentation to find their material composition and mechanical properties. Using both techniques the correlation of the material composition and the average modulus was determined. It could be shown that the average modulus of the degradation layer is distinctly lower than that of the base material. The local average modulus of degrading implant highly depends on the magnesium concentration and the accumulation of elements from the environment. A decrease in magnesium concentration leads to a decrease in the average modulus. Thus, the degrading implant had a lower stiffness than the initial structure.

Assessment of Physical and Chemical Stability of Different Magnesium Compounds in Tablets

Modern lifestyle, excessive chemicalization of agricultural products, excessive processing and refining of food, cause a decrease in daily intake of magnesium, cation with an extremely important role in prevention and treatment of many diseases. As a result, there arises the need for extra magnesium intake in the form of dietary supplements. In this study were evaluated the physical and chemical stability of magnesium-containing tablets, depending on the active compound and the excipients used. Magnesium tablets in the form of orotate, lactate, citrate, oxide and hydroxide were taken into study and physical and chemical stability were observed over the validity period, at 6 and at 12 months after expiry date. There were no changes in physical and chemical stability during the validity period of the studied tablets. At 6 months after the expiry date, were observed variations in chemical composition with decrease in magnesium concentration to 98% of the declared value, only in the case of tablets containing magnesium lactate. At 12 months, the magnesium concentration decreased in all analysed samples, with no statistically significant differences (p[0.05) between the types of magnesium compounds � 95% for the orotate, 93% for the lactate, 90% for the oxide and hydroxide, respectively 85% for citrate. The results of this study indicate the therapeutically safety for using these tablets 6 months after the expiry date.

An experimental and modeling study to investigate brine-rock interactions during low salinity water flooding in carbonates

Injection of brines with carefully designed ionic compositions into oil-wet carbonate rocks at high temperatures has shown to alter their wettability towards a water-wet state and improve oil recovery. Various mechanisms have been postulated for this wettability alteration such as mineral dissolution and interaction of potential determining ions, such as Ca2+, Mg2+ and SO42−, with the carbonate surface. In this study, experimental and modeling work was performed to gain further insights into the geochemical interactions between carbonate rocks and modified brines. Single-phase static (equilibrium) and transport experiments were performed with various brines in limestone cores at 120 °C. The ionic compositions of the effluent samples were monitored using ion chromatography. A mechanistic model for the wettability alteration process was developed in UTCHEM-IPHREEQC based on key geochemical interactions. The calcite surface was assumed to consist of positive and negative sites and their interactions with potential determining ions were considered assuming local equilibrium. The model assumed the degree of oil-wetness to depend on the amount of organic acid attached on the surface, which in-turn was dependent on the geochemistry of the system. Results of static experiments performed with crushed limestones and brines showed an increase in calcium concentration and a decrease in magnesium concentration in the supernatant brines. The effluent concentrations from single-phase brine corefloods in limestone cores showed an increase in calcium concentration, a decrease in magnesium concentration and a delay in sulfate concentration. Three key geochemical interactions were identified based on these results: mineral dissolution, surface dolomitization and sulfate adsorption. A good qualitative agreement was observed between single-phase experiments and simulations, suggesting that the model was able to accurately capture the geochemistry. The simulation results showed good agreement with zeta potential and oil recovery results reported in the literature.

Influence of the administration of selenium compounds on tissue magnesium concentration in rats

Magnesium and selenium belong to important bioelements. Magnesium is the second most abundant intracellular macroelement, which takes part in the metabolism of carbohydrates, nucleic acids, protein and lipids. Selenium is an essential microelement, whose deficit has been stated in many different pathological states. Much research on safe and effective selenium supplementation has been performed for the last fifty years but the results still remain unsatisfactory. The aim of our study was to investigate the influence of inorganic sodium selenite Na 2 SeO 3 and two selenoorganic compounds synthetized at our chair on magnesium concentration in tissues of adolescent male Wistar rats. Inorganic selenite was administered as a water solution, whereas organic compounds: 4-(o-tolilo)-selenosemikarbazyd of 2-chlorobenzoic acid of a chain structure (ORG-C) and 3-(o-chlorobenzoylamino)-2-(o-tolylimino)-4-methyl-4-selenazoline of a ring structure (ORG-R) were suspended in emulsion (oil, arabic gum and water). Selenium compounds were given to rats at a dose of 5⋅10 –4 mg Se g –1 b.w. once a day for a period of 10 days. The control group was treated with saline. The administration was performed with use of a stomach tube. In comparison to the control group, selenium supplementation caused decrease in magnesium concentration in kidney and lung tissues, but did not cause any changes in the brain and heart muscle. In the liver and spleen it was only ring selenazoline that affected magnesium concentration, increasing it in the liver and decreasing in the spleen. In the femoral muscle it was only the selenosemicarbazide chain that exerted the significant effect causing a decrease in Mg concentration vs the control group. Selenium supplementation influences the tissue magnesium concentrations depending on tissue and structure of the supplement. Irrespective of the administered compound, it lowered magnesium in kidneys and lungs but caused no changes in the brain and heart muscle. In the liver, spleen and femoral muscle, alterations in the magnesium concentration were dependent on the provided supplement.

High resolution distribution of magnesium and strontium and the evaluation of Mg/Ca thermometry in Recent brachiopod shells

High resolution distribution of magnesium and strontium determined by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) are presented in this study for Recent brachiopod shells. The concentration of magnesium and strontium decreases in a similar fashion from the outer to inner regions of shells of rhynchonelliform species but remains unaltered in craniid brachiopods. In rhynchonelliform brachiopods with low-magnesium shells, there is a characteristic chemical profile with an abrupt decrease in magnesium concentration from the primary layer towards the secondary layer until it reaches a region in which the values are almost constant. In addition, there is a proportional relationship in magnesium concentration between primary and secondary layers. Both findings demonstrate the biological control in magnesium incorporation in rhynchonelliform brachiopods confirming previously reported findings. Calculated Mg/Ca ratios based on magnesium concentrations within the innermost region of the secondary layer show that rhynchonelliform brachiopods can record seawater temperature. This finding opens up the possibility of using Mg/Ca (palaeo) thermometry even within the context of biological control and the potential application of Mg/Ca ratios as a seawater temperature proxy in fossil brachiopods.

Neuroprotective and symptomatological action of memantine relevant for Alzheimer's disease--a unified glutamatergic hypothesis on the mechanism of action.

The involvement of glutamate mediated neurotoxicity in the pathogenesis of Alzheimer's disease is finding increasingly more acceptance in the scientific community. Central to this hypothesis is the assumption that in particular glutamate receptors of the N-methyl-D-aspartate (NMDA) type are overactivated in a tonic rather than a phasic manner. Such continuous mild activation leads under chronic conditions to neuronal damage. Moreover, one should consider that impairment of plasticity (learning) may result not only from neuronal damage per se but also from continuous activation of NMDA receptors. To investigate this possibility we tested whether overactivation of NMDA receptors using either non-toxic doses/concentrations of a direct NMDA agonist or through an indirect approach--decrease in magnesium concentration--produces deficits in plasticity. In fact NMDA both in vivo (passive avoidance test) and in vitro (LTP in CA1 region) impaired learning and synaptic plasticity. Under these conditions memantine which is an uncompetitive NMDA receptor antagonist with features of "improved magnesium" (voltage dependence, affinity) attenuated the deficit. The more direct proof that memantine can act as a surrogate for magnesium was obtained in LTP experiments under low magnesium conditions. In this case as well, impaired LTP was restored in the presence of therapeutically relevant concentrations of memantine (1 microM). In vivo, doses leading to similar brain/serum levels produce neuroprotection in animal models relevant for neurodegeneration in Alzheimer's disease such as neurotoxicity produced by inflammation in the NBM or beta-amyloid injection to the hippocampus. Hence, we postulate that if in Alzheimer's disease overactivation of NMDA receptors occurs indeed, memantine would be expected to improve both symptoms (cognition) and slow down disease progression because it takes over the physiological function of magnesium.

Age-dependent differences in the relationship between plasma and brain extracellular fluid concentrations of magnesium after MgSO4 infusions in miniswine.

Magnesium is a potential neuroprotective agent in the treatment of head injury and ischemia whose efficacy is likely determined by increases in brain extracellular fluid (ECF) magnesium, which in turn depends on its concentration in plasma. The objectives of this study were to: 1) examine the effects of increasing plasma magnesium concentration ([Mg]plasma) to 4-6 mM on brain ECF magnesium concentration ([Mg]ECF) and 2) determine whether maturational changes occur in the transfer of magnesium into brain ECF for newborn and more mature (approximately 1 month old) miniswine. Increases in [Mg]plasma by systemic administration of MgSO4 resulted in similar maximal elevations in brain [Mg]ECF for both age groups (193+/-76% versus 253+/-106% of control for newborn and 1-month-old miniswine, respectively). Calculations of half-lives (t1/2) for the increase and decrease in magnesium concentration (t1/2 uptake and t1/2 clearance) were used to characterize magnesium kinetics in plasma and brain ECF. Plasma magnesium uptake was shorter in 1-month-old (t1/2 = 11.1+/-0.9 min) compared with newborns (12.9+/-1.7 min, p < 0.05). The faster increase in [Mg]plasma probably contributed to a faster uptake of brain [Mg]ECF in 1-month-old compared with newborn swine (t1/2 uptake = 27.9+/-12.8 versus 46.0+/-20.9 min, respectively, p < 0.05). Although plasma magnesium clearance was shorter in 1-month-old swine compared with newborn (t1/2 = 34.3+/-7.0 versus 74.7+/-33.7 min, respectively, p < 0.05), the clearance of magnesium from the brain ECF was similar for each age group. Reductions in blood pressure and heart rate occurred during hypermagnesemia and were similar in each age group. This study shows that acute elevations in [Mg]plasma to 4-6 mM result in similar relative increases in brain [Mg]ECF for both newborn and 1-month-old miniswine. However, there are maturational differences, as demonstrated by the faster rate of magnesium uptake into the ECF observed in the older miniswine.

The action of excessive, inorganic silicon (Si) on the mineral metabolism of calcium (Ca) and magnesium (Mg).

The influence of silicon treatment on the levels of calcium and magnesium in blood serum and tissues was studied in rats. The concentrations of both elements were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic silicon compound--sodium metasilicate nonahydrate (Na2SiO3.9H2O (REACHIM, USSR)), dissolved in the animals' drinking water. A decrease of magnesium concentration in serum was observed with accompanying elevation of registered calcemia. Moreover, a reduction of tissue calcium levels was found with a simultaneous increase of magnesium tissue pool. The results provide evidence for silicon involvement in mineral metabolism. It could result in a modification of pathological processes concerning bone tissue.

Water at the Outlet of the St. Lawrence River Part I - Sampling and Major Cations

Abstract The St. Lawrence River exports important loads of contaminants to the estuary, but good estimates of annual loadings are presently not available. During two years (1989–91), discrete and composite samples were taken on a daily basis at the water intake of the drinking water treatment plant of Lévis in front of Québec City. Our data indicate that discrete samples are representative of the bulk of the water and that magnesium or calcium measurements provide valuable information on the species transported to the estuary in the dissolved phase. Any decrease in magnesium concentrations at Lévis is the result of relative flow increases from the tributaries of the river. Using high flow episodes in tributaries and daily magnesium measurements at Lévis, the time of transport of the dissolved phase from many sources along the river has been evaluated. At high flow, the time of transport from the Carillon Dam (on the Ottawa River) to Lévis is 11 days, while it is 8 days from Beauharnois. With these data, a predictive model using magnesium (or calcium) as the chemical parameter characterizing the dissolved phase of the St. Lawrence River at the mouth of the estuary was developed. Loadings to the estuary of any dissolved contaminant can now be estimated by combining daily calculated flow values with daily measured water composition at Levis.

Changes in blood composition of pregnant cows during the onset of hypomagnesaemia.

Magnesium, calcium, phosphate, total protein and free fatty acid concentrations, and a lipase activity using p-nitrophenylpalmitate NP-C16) as a substrate, were determined in the serum of 15 pregnant Aberdeen Angus cows grazing a Phalaris tuberosa pasture with a tendency to induce tetany. A gradual decrease in magnesium concentrations, but no definite change in the other parameters, was observed when the results were plotted directly against the time of the experiment. When the results were plotted as a function of the stage of pregnancy or lactation of the animals, magnesium concentrations showed a more steady decrease which was associated with increases in calcium concentrations and, at the lowest magnesium concentrations, with increases in phosphate concentrations. Total proteins and free fatty acids remained fairly constant and the highest lipase activity was associated with parturition. The lowest magnesium concentrations in serum did not correspond with high levels of either lipase or free fatty acids. The hypomagnesaemia observed in this experiment was attributed to the high potassium:calcium and magnesium ratio in the pasture and to the physiological condition (pregnant and lactating) of the animals. None of the parameters evaluated in this paper would be more sensitive than serum magnesium levels for the early detection of the conditions that predispose grazing cattle to grass tetany.

Calcium-dependent exocytosis in an in vitro secretory granule plasma membrane preparation from sea urchin eggs and the effects of some inhibitors of cytoskeletal function.

Egg cortical granules remain attached to the egg plasma membrane when the egg is ruptured. We present evidence that demonstrates that, when the cytoplasmic face of the egg plasma membrane is exposed to micromolar calcium concentrations, an exocytosis of the cortical granules occurs which corresponds to the cortical granule exocytosis seen when the egg is fertilized. The calcium sensitivity of the preparation is decreased by an increase in magnesium concentration and increased by a decrease in magnesium concentration. Exocytosis is inhibited by trifluoperazine (half inhibition at 6 microM), a drug that inhibits the action of the calcium-dependent regulatory protein calmodulin. Colchicine, vinblastine, nocodazole, cytochalasin B, phalloidin, N-ethylmaleimide-modified myosin subfragment 1, and antibody to actin are without effect on this in vitro exocytosis at concentrations that far exceed those required to disrupt microtubules and microfilaments. Conditions are such that penetration to the exocytotic site is optimal. It is unlikely, therefore, that either actin or tubulin participate intimately in exocytosis. Our data also exclude on quantitative grounds several other mechanisms postulated to account for the fusion of the secretory granule with the plasma membrane.

Differences in metal content of the heart muscle in death from ischemic heart disease

In a group of patients dying suddenly from ischemic heart disease, the uninfarcted heart muscle contained significantly lower concentrations of magnesium, iron, and potassium and a significantly higher concentration of calcium than the heart muscle from a group of normal controls and a group of patients dying more than three months after a coronary thrombosis. The late death group had significantly lower concentrations of manganese and copper than the normal group, and a slight decrease in magnesium concentration which was probably significant. There was no significant difference in the sodium concentration between the three groups. The results are discussed in relation to the increased death rate from ischemic heart disease in areas with soft drinking water, and possible dietary deficiencies in mineral salts.

Secretion of magnesium by dog parotid gland.

Prolonged, steady secretion of saliva results in a decrease in magnesium concentration until a steady state is reached after about 40 min. During this period the glandular concentration of magnesium also diminishes. The salivary magnesium concentration increases as the rate of flow decreases. This effect is most marked at flows below about 0.2 ml/min. The amount of magnesium in saliva varies directly with that in plasma. Since over a wide range of magnesium plasma concentrations the saliva/plasma ratio is approximately one, and because no change in concentration occurs during the stop flow procedure, it is suggested that the salivary secretion of magnesium is a passive process. Stop flow studies using Mg28 indicate that the primary site for transport of magnesium from plasma to saliva is in the intralobular ducts. These results are consistent with the hypothesis that electrolytes are transferred from plasma to saliva primarily by activity of the duct cells, that these processes are not coupled, and that they can proceed at varying and independent rates.