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Electrolyte & Blood Pressure : E & BP Dec 2023Hypermagnesemia is a rare but potentially fatal electrolyte disorder often overlooked because of its unfamiliarity. Magnesium is regulated through a balance of bone,...
Hypermagnesemia is a rare but potentially fatal electrolyte disorder often overlooked because of its unfamiliarity. Magnesium is regulated through a balance of bone, intestinal absorption, and renal excretion. Hypermagnesemia typically arises from excessive magnesium intake or reduced renal excretion; however, it also occurs in patients with normal kidney function. Herein, we report two cases of hypermagnesemia in patients taking magnesium hydroxide for constipation. The first case involved an 82-year-old woman with end-stage renal disease who developed metabolic encephalopathy due to hypermagnesemia, after taking 3,000 mg of magnesium hydroxide daily for constipation. Her magnesium level was 9.9 mg/dL. Her treatment involved discontinuing magnesium hydroxide and continuing hemodialysis, which led to her recovery. In the second case, a 50-year-old woman with a history of cerebral hemorrhage and mental retardation developed hypermagnesemia despite having normal renal function. She was also taking magnesium hydroxide for constipation, and her magnesium level was 11.0 mg/dL. She experienced cardiac arrest while preparing for continuous renal replacement therapy (CRRT). After achieving return of spontaneous circulation, CRRT was initiated, and her magnesium level showed a decreasing trend. However, vital signs and lactate levels did not recover, leading to death. These cases highlight the importance of prompt diagnosis and intervention for hypermagnesemia and the need to regularly monitor magnesium levels in individuals receiving magnesium-containing preparations, especially those with impaired kidney function.
PubMed: 38152602
DOI: 10.5049/EBP.2023.21.2.66 -
Bioactive Materials Nov 2022Osteosarcoma (OS) tissue resection with distinctive bactericidal activity, followed by regeneration of bone defects, is a highly demanded clinical treatment....
Osteosarcoma (OS) tissue resection with distinctive bactericidal activity, followed by regeneration of bone defects, is a highly demanded clinical treatment. Biodegradable Mg-based implants with desirable osteopromotive and superior mechanical properties to polymers and ceramics are promising new platforms for treating bone-related diseases. Integration of biodegradation control, osteosarcoma destruction, anti-bacteria, and bone defect regeneration abilities on Mg-based implants by applying biosafe and facile strategy is a promising and challenging topic. Here, a black Mn-containing layered double hydroxide (LDH) nanosheet-modified Mg-based implants was developed. Benefiting from the distinctive capabilities of the constructed black LDH film, including near-infrared optical absorption and reactive oxygen species (ROS) generation in a tumor-specific microenvironment, the tumor cells and tissue could be effectively eliminated. Concomitant bacteria could be killed by localized hyperthermia. Furthermore, the enhanced corrosion resistance and synergistic biofunctions of Mn and Mg ions of the constructed black LDH-modified Mg implants significantly facilitated cell adhesion, spreading and proliferation and osteogenic differentiation , and accelerated bone regeneration . This work offers a new platform and feasible strategy for OS therapeutics and bone defect regeneration, which broadens the biomedical application of Mg-based alloys.
PubMed: 35386440
DOI: 10.1016/j.bioactmat.2022.01.032 -
Materials (Basel, Switzerland) Nov 2022Herein, novel monodisperse basic magnesium sulfate whiskers (5Mg(OH)·MgSO·7HO) were prepared under low-temperature and atmospheric-pressure conditions, using the...
Herein, novel monodisperse basic magnesium sulfate whiskers (5Mg(OH)·MgSO·7HO) were prepared under low-temperature and atmospheric-pressure conditions, using the admixture sodium citrate. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, selected area electron diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the structure and morphology of the whisker products. The analysis results showed that the product was composed of high-purity basic magnesium sulfate whiskers. The lengths and diameters of the whiskers were 10-20 μm and 0.1-0.2 μm, respectively, and their aspect ratios were higher than 30. The formation mechanism of 5Mg(OH)·MgSO·7HO involved direct assembly from the precursors without the formation of magnesium hydroxide for redissolution. High-purity MgO whiskers with smooth surfaces were prepared using the as-prepared whisker products via thermal decomposition. Thus, the findings of this study can provide technical support for the cost-effective industrial-scale preparation of basic magnesium-sulfate whiskers and associated whisker products.
PubMed: 36431506
DOI: 10.3390/ma15228018 -
Journal of Dairy Science Feb 2023The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)] and its interaction...
Production, physiological response, and calcium and magnesium balance of lactating Holstein cows fed different sources of supplemental magnesium with or without ruminal buffer.
The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)] and its interaction with ruminal buffer (sodium sesquicarbonate) supplementation on production, Ca and Mg balance, and overall physiological response of mid-lactation Holstein dairy cows. Sixty cows averaging 40.5 ± 7.0 kg of milk/d were used. Treatments were assigned following a 2 × 2 factorial arrangement: (1) MgO, (2) MgO + buffer, (3) CaMg(OH), or (4) CaMg(OH) + buffer. Diets were formulated to have 16.5% of crude protein, 1.82 Mcal/kg of net energy for lactation, 0.67% Ca, 0.39% P, and 0.25% Mg, all on a dry matter (DM) basis. Treatments were individually top dressed. Milk production, composition, and DM intake were evaluated. A subsample of 20 cows were randomly selected for the evaluation of Ca and Mg balance, blood gases, and electrolytes. Ruminal fluid was also collected for evaluation of pH and Ca and Mg solubility. Effects of Mg source, buffer, and the interaction Mg source × buffer were analyzed through orthogonal contrasts. An interaction of Mg source × buffer was found for DM intake and feed efficiency, in which cows fed CaMg(OH) had a similar feed efficiency regardless of ruminal buffer inclusion; however, when cows were fed MgO, the inclusion of buffer reduced feed efficiency. No effects on body weight and milk yield were observed. Buffer addition tended to increase the concentrations of fat, protein, and solids-not-fat, without affecting the yields of these milk components. Magnesium source and buffer did not affect ruminal fluid, blood, urine, or fecal pH; however, buffer supplementation increased urinary pH. Treatment with CaMg(OH) increased blood concentration of HCO, total CO, and base excess compared with cows fed MgO. No differences were observed in the ruminal solubility of Ca and Mg or on milk or urinary Ca and Mg excretion. Greater plasma Mg concentration was observed for animals fed MgO compared with cows fed CaMg(OH); however, both sources were above the threshold recommended in the literature for dairy cows. Also, a reduction in fecal Mg excretion was observed in animals fed CaMg(OH). In summary, we provide evidence that CaMg(OH) could replace MgO without affecting performance, overall physiological response, or Ca and Mg balance of mid-lactating dairy Holstein cows.
Topics: Female; Cattle; Animals; Lactation; Magnesium; Calcium; Magnesium Oxide; Milk; Diet; Calcium, Dietary; Rumen; Animal Feed; Digestion
PubMed: 36526456
DOI: 10.3168/jds.2022-22583 -
Polymers Nov 2023The thermal decomposition product of magnesium hydroxide (MH) is magnesium oxide (MgO), which serves as the foundational material for fireproof layer construction in the...
The thermal decomposition product of magnesium hydroxide (MH) is magnesium oxide (MgO), which serves as the foundational material for fireproof layer construction in the condensed phase. However, the weak interaction force between particles of MgO generated by thermal decomposition leads to the insufficient strength and poor adhesion ability of the fireproof layer. The fireproof layer was easily damaged and detached in this study, resulting in the low flame-retardant efficiency of MH. In this work, polycarbosilane (PCS) and divinyl benzene (DVB) were used to modify MH, and EVA/MH/PCS/DVB composites were made via melt blending. The flame-retardant properties of EVA/MH/PCS/DVB were evaluated using the limiting oxygen index (LOI), vertical combustion (UL-94), and a cone calorimeter (CONE). The thermal stability of the composites and flame retardants was analyzed using a thermogravimetric analyzer. The char layer structure was observed and analyzed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The results indicate that the LOI of the EVA/MH/PCS/DVB with 50 wt.% flame retardants in total was as high as 65.1, which increased by 160% in comparison with EVA/MH. Furthermore, the total smoke production (TSP) of the EVA/MH/PCS/DVB composite decreased by 22.7% compared to EVA/MH/PCS; the thermal stability of the MH/PCS/DVB and EVA/MH/PCS/DVB improved to some extent; and the compact residual char after the combustion of EVA/MH/PCS/DVB had fewer cracks due to the adhesive effect induced by PCS/DVB.
PubMed: 38006164
DOI: 10.3390/polym15224440 -
Medicine and Pharmacy Reports Jan 2022The aim of this study was to evaluate the acid-neutralizing capacity (ANC) and other properties of antacid drugs marketed in Morocco.
AIM
The aim of this study was to evaluate the acid-neutralizing capacity (ANC) and other properties of antacid drugs marketed in Morocco.
METHODS
Samples of 12 antacids were collected from pharmacies and were subjected to the test described in the US Pharmacopoeia in order to measure their ANC. Other properties such as price and sodium content were also studied.
RESULTS
All the tested brands met the minimal requirement of 5 mEq. However, Aluminum hydroxide/Magnesium hydroxide combinations showed a superior acid-neutralizing capacity over other products and oral suspensions showed better results compared to other pharmaceutical forms. Regarding the cost of antacids, Aluminum hydroxide/Magnesium hydroxide combinations and calcium carbonate/magnesium carbonate combinations showed the most favorable ANC/price ratio. Some of the antacids studied contain a high amount of sodium.
CONCLUSION
All the antacids marketed in Morocco meet the USP requirement regarding their ANC. However, the ANC value should be included in the antacids' labels so that both patients and physicians can choose the most appropriate product. The ANC value should be evaluated according to the dose of the active substance instead of the minimum labeled dosage in order to allow a better result interpretation.
PubMed: 35720246
DOI: 10.15386/mpr-2082 -
Medical Science Monitor : International... Jun 2020BACKGROUND The goal of the present work was to assess the antibacterial activity of nano-magnesium hydroxide (NMH) against Streptococcus mutans (S. mutans) and to...
BACKGROUND The goal of the present work was to assess the antibacterial activity of nano-magnesium hydroxide (NMH) against Streptococcus mutans (S. mutans) and to explore the antimicrobial function of AH Plus™ sealer incorporating NMH. MATERIAL AND METHODS The antimicrobial behavior of NMH against S. mutans was evaluated with bactericidal tests. A modified direct contact test was used to assess the antimicrobial activity of unset AH Plus containing NMH after 5 minutes, 20 minutes, and 60 minutes of contact with bacteria. The antimicrobial effects and the amount of surface-adhering bacteria of the solidified materials were explored by SEM and confocal laser scanning microscopy, respectively. RESULTS NMH powder presented excellent antimicrobial activity against S. mutans. Mg²⁺ and OH⁻ were not the main factors resulting in bacterial death. Approximately 93.1% and 98% of the S. mutans were killed in the AH Plus+7% NMH group after incubation for 5 minutes and 20 minutes, respectively. AH Plus with 5% or 7% NMH were more potent against S. mutans compared with AH Plus alone (P<0.05). Moreover, the antibacterial function of AH Plus was lost after setting. NMH enabled the solidified AH Plus to still have antibacterial properties on the seventh day. CONCLUSIONS NMH can be used to modify AH Plus sealer to eradicate residual bacteria and prevent reinfection.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Biofilms; China; Humans; Magnesium Hydroxide; Materials Testing; Microbiota; Root Canal Filling Materials; Streptococcus mutans; Zinc Oxide-Eugenol Cement
PubMed: 32503962
DOI: 10.12659/MSM.922920 -
Biomaterials Advances Mar 2022One of the most common magnesium (Mg) applications in the biomedical field is in cardiovascular stents. Although Mg is an essential element for homeostasis, Mg is highly...
One of the most common magnesium (Mg) applications in the biomedical field is in cardiovascular stents. Although Mg is an essential element for homeostasis, Mg is highly reactive, and locally high Mg concentrations can have toxic effects on the surrounding tissue. One strategy to circumvent the Mg toxicity is using coatings or surface modifications that prevent the leaching of excessive Mg ions. In the current study, commercially pure magnesium (c.p Mg) was modified through plasma electrolytic oxidation (PEO) to produce a protective coating primarily composed of Mg oxide (MgO) and Mg hydroxide (Mg(OH)), which limits leaching of free Mg ions from the base material. As we intend to use this material to produce vascular stents, a biological evaluation of its performance is warranted. Primary human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) were the study object. The leaching of free Mg ions from the oxidized materials was investigated, as was its effect on local pH changes. We also investigated the influence of corrosion products, the effects of elevated free Mg concentrations and pH on the cellular behavior on the integrity of monolayers of HUVECs was studied in a static and dynamic model. Results showed that the harmful effect of Mg on cells due to changes in pH and a high concentration of Mg ions could decrease with the influence of flow diffusing corrosion products such as MgO, Mg(OH), and H among the system. Independently, Mg concentration and pH affected the cell activity of SMCs and HUVECs. Finally, to investigate the influence of leachables on vasomotor function, we exposed porcine aortic rings to PEO-modified Mg stents and assessed endothelial-dependent relaxation. Pure Mg reduced vasorelaxation from 100% in control samples to 30%. Oppositely, PEO-modified Mg did not affect the vasomotor function. Overall, we conclude from this study that the use of PEO coatings reduces the degradation rate of the material reducing the Mg release resulting in better cell viability and vessel function compared to the bare material.
Topics: Alloys; Animals; Coated Materials, Biocompatible; Human Umbilical Vein Endothelial Cells; Humans; Magnesium; Magnesium Hydroxide; Magnesium Oxide; Swine
PubMed: 35581088
DOI: 10.1016/j.msec.2022.112693 -
Polymers Jun 2023The poor processing and rheological properties of highly filled composites caused by the high loading of fillers can be improved with the use of maleic anhydride grafted...
The poor processing and rheological properties of highly filled composites caused by the high loading of fillers can be improved with the use of maleic anhydride grafted polyethylene wax (PEWM) as compatibilizer and lubricant. In this study, two PEWMs with different molecular weights were synthesized by melt grafting, and their compositions and grafting degrees were characterized by Fourier transform infrared (FTIR) spectroscopy and acid-base titration. Subsequently, magnesium hydroxide (MH)/linear low-density polyethylene (LLDPE) composites with 60 wt% of MH were prepared using polyethylene wax (PEW) and PEWM, respectively. The equilibrium torque and melt flow index tests indicate that the processability and fluidity of MH/MAPP/LLDPE composites are significantly improved with the addition of PEWM. The addition of PEWM with a lower molecular weight leads to a substantial reduction in viscosity. The mechanical properties are also increased. The limiting oxygen index (LOI) test and cone calorimeter test (CCT) show that both PEW and PEWM have adverse effects on flame retardancy. This study provides a strategy to simultaneously improve the processability and mechanical properties of highly filled composites.
PubMed: 37299373
DOI: 10.3390/polym15112575 -
Biomedicines Apr 2023In recent years, magnesium hydroxide has been widely studied due to its bioactivity and biocompatibility. The bactericidal effects of magnesium hydroxide nanoparticles...
In recent years, magnesium hydroxide has been widely studied due to its bioactivity and biocompatibility. The bactericidal effects of magnesium hydroxide nanoparticles on oral bacteria have also been reported. Therefore, in this study, we investigated the biological effects of magnesium hydroxide nanoparticles on inflammatory responses induced by periodontopathic bacteria. Macrophage-like cells, namely J774.1 cells, were treated with LPS derived from and two different sizes of magnesium hydroxide nanoparticles (NM80/NM300) to evaluate their effects on the inflammatory response. Statistical analysis was performed using an unresponsive Student's t-test or one-way ANOVA followed by Tukey's post hoc test. NM80 and NM300 inhibited the expression and secretion of IL-1β induced by LPS. Furthermore, IL-1β inhibition by NM80 was dependent on the downregulation of PI3K/Akt-mediated NF-κB activation and the phosphorylation of MAPK molecules such as JNK, ERK1/2, and p38 MAPK. By contrast, only the deactivation of the ERK1/2-mediated signaling cascade is involved in IL-1β suppression by NM300. Although the molecular mechanism involved varied with size, these results suggest that magnesium hydroxide nanoparticles have an anti-inflammatory effect against the etiologic factors of periodontopathic bacteria. These properties of magnesium hydroxide nanoparticles can be applied to dental materials.
PubMed: 37238962
DOI: 10.3390/biomedicines11051291