Cytotoxicity, genotoxicity and mutagenicity of mixed ternary mononuclear Mg complex based on valproic acid with 1,10-phenanthroline in Saccharomyces cerevisiae and V79 cells.

Valproic acid (VA) is a widely used drug for the treatment of diseases affecting the central nervous system. Due to its epigenetic modulatory potential, it has been studied for possible therapeutic application in anticancer therapies. However, the VA exhibits different side effects in its application. Thus, synthetic coordination complexes with valproate can generate promising candidates for new active drugs with reduced toxicity. In this sense, we investigated the genotoxic and mutagenic potential of the sodium valproate and of the mixed ternary mononuclear Mg complex based on VA with 1,10-phenanthroline (Phen) ligand - [Mg (Valp)2Phen], in Saccharomyces cerevisiae and V79 cells. The MTT and clonal survival assays in V79 cells indicated that the Mg complex has higher cytotoxicity than sodium valproate. A similar cytotoxicity profile is observed in yeast. This fact is possibly due to the intercalation capacity of [Mg(Valp)2Phen], inducing DNA strand breaks, as observed in the comet assay and micronucleus test. In this sense, members of the NER, HR, NHEJ and TLS repair pathways are required for the repair of DNA lesions induced by [Mg(Valp)2Phen]. Interestingly, BER proteins apparently increase the cytotoxic potential of the drug. Furthermore, the [Mg(Valp)2Phen] showed higher cytotoxicity in V79 cells and yeast when compared to sodium valproate indicating applicability as a cytotoxic agent.

Association of Vitamin D and magnesium levels with severity and mortality in patients with COVID-19.

OBJECTIVE: The study aimed to determine the association between serum magnesium and Vitamin D levels with the severity and mortality by coronavirus disease 19 (COVID-19) in hospitalized patients. METHOD: Men and women over 18 years of age with probable COVID-19 were enrolled in a case-control study. Patients with a positive or negative test for Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were allocated into case or control groups, respectively. Vitamin D deficiency was defined by concentrations < 20 ng/mL and hypomagnesemia by serum levels < 1.8 mg/dL. RESULTS: A total of 54 patients, 30 women and 24 men, were enrolled and allocated into the groups with (n = 27) and without (n = 27) COVID-19. The logistic regression analysis showed that Vitamin D deficiency (odds ratio [OR] = 6.13; 95% confidence intervals [CI]: 1.32-28.34) and insufficiency (OR = 0.12; 95% CI: 0.02-0.60) are significantly associated with hospitalization. However, Vitamin D disorders and hypomagnesemia were not associated with mortality. CONCLUSIONS: The results of the present study revealed that Vitamin D disturbances, but not hypomagnesemia, are associated with the severity of SARS-CoV-2.

OBJETIVO: Determinar la asociación entre los niveles séricos de vitamina D y de magnesio con la gravedad y la mortalidad de la COVID-19 en pacientes hospitalizados. MÉTODO: Hombres y mujeres mayores de 18 años con probable COVID-19 fueron enrolados en un estudio de casos y controles. Los pacientes con una prueba positiva o negativa para SARS-CoV-2 fueron asignados en los grupos de casos y de controles, respectivamente. RESULTADOS: Un total de 54 pacientes, 30 mujeres y 24 hombres, fueron enrolados y asignados a los grupos COVID-19 (n = 27) y control (n = 27). El análisis de regresión logística mostró que la deficiencia de vitamina D (odds ratio [OR]: 6.13; intervalo de confianza del 95% [IC95%]: 1.32-28.34) y la insuficiencia de vitamina D (OR: 0.12; IC95%: 0.02-0.60) se asocian significativamente con hospitalización. Sin embargo, las alteraciones de la vitamina D y la hipomagnesemia no se asociaron con mortalidad. CONCLUSIONES: Los resultados del presente estudio revelaron que las alteraciones de la vitamina D, pero no la hipomagnesemia, se asocian con la gravedad de la COVID-19.

Effects of Dolomitic Limestone on the Properties of Magnesium Oxysulfate Cement.

This study investigated the effects of substituting magnesium oxide (MgO) with dolomitic limestone (DL) on the mechanical and physical properties of magnesium oxysulfate (MOS) cement. Additionally, the hydration formation phases and the influence of the molar ratio on the MOS cement's performance were examined. The corresponding action mechanisms were identified and explored by compressive strength tests, scanning electron microscopy (SEM), X-ray diffraction (XRD), isothermal calorimetry, and a thermogravimetric analysis (TGA). The results showed that replacing MgO with DL decreased the reaction speed and heat release rate generated in the hydration process of the MOS cement. This substitution also reduced the quantity of non-hydrated MgO particles and delayed the formation of Mg(OH)2. The diminished formation of Mg(OH)2 contributed to an increase in the apparent porosity of pastes containing DL, thus alleviating internal stresses induced by Mg(OH)2 formation and enhancing their mechanical strength after 28 days of curing. Conversely, the increased porosity improved the CO2 diffusion within the structure, promoting the formation of magnesium carbonates (MgCO3). Through the characterization of the cement matrix (XRD and TGA), it was possible to identify phases, such as the brucite, periclase, and 318 phases. The obtained results revealed the potential of incorporating mineral fillers like limestone as a promising approach to producing MOS cement with a reduced environmental impact and better properties at higher curing ages.

Effects of monensin and a blend of magnesium oxide on performance, feeding behavior, and rumen morphometrics of Zebu beef cattle fed high-starch diets.

This study aimed to evaluate the effects of a blend of different sources of magnesium oxide associated or not with monensin, on productive, ruminal, and nutritional parameters of steers. Eighty-four Nellore steers with an initial body weight (BW) of 367.3 ±â€…37.9 kg were allocated to one of 28 pens, with three steers per pen. Each pen was considered an experimental unit. Using a completely randomized design with a 2 × 2 factorial arrangement, the following treatments were assigned to each pen: 1) Control (CON)-a basal diet without additive inclusion; 2) Magnesium oxide blend (MG)-basal diet plus a magnesium-based product (pHix-up, Timab Magnesium, Dinard, France) provided at 0.50% of dry matter (DM); 3) Monensin (MON)-basal diet plus 25 mg/ kg of DM of sodium monensin (Rumensin, Elanco Animal Health, Greenfield, IN); and 4) MG association with MON-basal diet plus MG + MON, at the same doses of the individual treatments. The experimental period lasted 100 d. Blood samples were collected on days 0, 13, and 70 to determine d-lactate levels. Daily feed intake was recorded, and animal ingestive behavior was visually observed on days 66 and 67. On day 70, skeletal muscle tissue samples were obtained through biopsy for gene expression analysis. At the end of the experimental period, carcass ultrasonography was conducted. Subsequently, the steers were slaughtered, and rumen epithelium samples were collected for morphometric analysis. The use of monensin, of magnesium oxide blend, and their interactions, were treated as fixed effects, while the pens were considered as a random effect. Statistical differences were considered when P < 0.05. Steers-fed MG-containing diets consumed approximately 0.6 kg more DM per day than those fed diets without this additive (P = 0.01; 11.3 vs. 11.9 kg/d). The inclusion of MG in the diet increased (P = 0.02) the average daily gain. There was a greater Longissimus muscle area (LMA) and LMA per 100 kg of BW (P ≤ 0.03) for steers-fed diets with MG. Steers-fed MON exhibited reduced mRNA expression of the Atrogin-1 and mTOR compared to steers-fed MG + MON diets (MON × MG: P ≤ 0.04). Steers-fed MON had 6.9% greater feed efficiency (P = 0.02). Papillae width was lesser for CON than other treatments (MON × MG: P = 0.02). In conclusion, the magnesium oxide blend improved performance and carcass traits in high-energy feedlot diets, while monensin enhanced feed efficiency, suggesting potential for their use as alternatives or complements in beef cattle nutrition.

Evaluation of Aluminum and Magnesium Absorption Following the Oral Administration of an Antacid Suspension Containing Magaldrate in Healthy Women Under Fed Conditions.

INTRODUCTION: Antacids are commonly used during pregnancy, and they are approved for the relief of symptoms of gastroesophageal reflux disease (GERD) during pregnancy. However, there are no reports of the quantification of the absorption of aluminum and magnesium in the antacid magaldrate in women. The aim of this study was to quantify the rate and magnitude of absorption of aluminum and magnesium in magaldrate. METHODS: An open-label, controlled, randomized, one-treatment study with a two-group design was conducted in healthy women in a fed state. The volunteers had a standard breakfast, and 30 min later, they were given a single-medication sachet containing 500 mg of sodium alginate, 267 mg of sodium bicarbonate, 800 mg of magaldrate, and 120 mg of simethicone (group A, n = 8) or no medication (group B, n = 2). Blood samples were obtained 36 h before and up to 12 h after antacid administration. The method used for quantification was inductively coupled plasma-mass spectrometry. RESULTS: There was no absorption of aluminum in any of the blood samples from the healthy volunteers who received the drug or in those from the control group. Magnesium was detected at normal concentrations. CONCLUSION: These findings suggest that the use of this antacid is safe and without risk in healthy women, including pregnant women. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov registration: NCT06367452.

Histomorphometric Study of Non-critical Bone Defect Repair after Implantation of Magnesium-substituted Hydroxyapatite Microspheres.

Objective The present study aims to analyze histomorphometrically the repair of a non-critical bone defect after implantation of hydroxyapatite (HA) microspheres substituted by magnesium (Mg). Methods Thirty rats were distributed into 3 experimental groups, evaluated at 15 and 45 days postoperatively: HAG (bone defect filled with HA microspheres); HAMgG (bone defect filled with HA microspheres replaced with 1 mol% Mg), and CG (bone defect without implantation of biomaterials). Results After 15 days, the biomaterials filled the entire defect extent, forming a new osteoid matrix between the microspheres. In the CG, this neoformation was restricted to the edges with the deposition of loose connective tissue with reduced thickness. At 45 days, new bone formation filled almost the entire extension of the bone defect in the 3 groups, with statistically significant osteoid deposition in the CG despite the reduced thickness compared with the HAG and HAMgG. The groups with biomaterial implantation displayed a more abundant osteoid matrix than at 15 days. Conclusion The biomaterials studied showed biocompatibility, osteoconductivity, and bioactivity. The Mg concentration in the substituted HA did not stimulate more significant bone formation than HA without this ion.

Influence of the activation time of magnesium surfaces on the concentration of active hydroxyl groups and corrosion resistance.

Magnesium alloys have been extensively studied as degradable biomaterials for clinical applications due to their biocompatibility and mechanical properties. However, their poor corrosion resistance can lead to issues such as osteolysis and the release of gaseous hydrogen. This study investigated the influence of the activation time of magnesium surfaces in a sodium hydroxide (NaOH) solution on the concentration of active hydroxyl groups and corrosion resistance. The results indicated that immersion time significantly influences the formation of a corrosion-resistant film and the distribution of surface hydroxyl groups. Specifically, specimens treated for 7.5 h exhibited the highest concentration of hydroxyl groups and the most uniform oxide film distribution. Electrochemical tests demonstrated capacitive behavior and passive surface formation for all evaluated times, with the 7.5-h immersion in NaOH yielding superior corrosion resistance, lower current density, and a more efficient and thicker protective film. SEM and EDS analyses confirmed increased formation of Mg(OH)2 for samples treated for 5 and 7.5 h, while a 10-h treatment resulted in a brittle, porous layer prone to degradation. Statistical analysis using ANOVA and Fisher's LSD test corroborated these findings. The optimal 7.5-h alkali treatment enhanced magnesium's corrosion resistance and surface properties, making it a promising candidate for orthopedic implants. However, further studies are necessary to assess biocompatibility and physiological responses before clinical implementation.

Magnesium, selenium and zinc deficiency compromises antioxidant defense in women with obesity.

Studies have shown that deficiencies in magnesium, selenium, and zinc in individuals with obesity compromise the endogenous antioxidant defense system. This study aimed to evaluate the impact of mineral deficiency on enzymatic antioxidant defense in women with obesity. The study involved 63 women with obesity (BMI ≥ 35 kg/m2) and 77 eutrophic women (BMI between 18.5 and 24.9 kg/m2). Variables such as fasting glucose, glycated hemoglobin, fasting insulin, and serum lipids were analyzed. Insulin resistance was measured using the homeostasis assessment model (HOMA-IR) and beta cell function using the homeostasis assessment model (HOMA-ß). Dietary intake of energy, macronutrients (including magnesium, zinc, and selenium), and plasma, erythrocyte, and urinary concentrations of these minerals were measured and analyzed. Serum cortisol, plasma leptin, plasma thiobarbituric acid reactive substances, and the activity of erythrocyte superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GPX), and erythrocyte catalase were also analyzed. Women with obesity had reduced plasma and erythrocyte concentrations and greater urinary excretion of all minerals compared to normal weight women (p < 0.05). There was a positive association between erythrocyte concentrations of zinc and selenium and the activity of the GPX and SOD enzymes in erythrocytes in women with obesity (p < 0.05), in addition to a positive association between serum insulin and the enzyme GPX, which is dependent on dietary selenium (p < 0.05). Individuals with obesity are deficient in magnesium, selenium, and zinc, which appears to impair the antioxidant defense system and contribute to important metabolic disorders such as oxidative stress in these patients.

Microstructural, Fluid Dynamic, and Mechanical Characterization of Zinc Oxide and Magnesium Chloride-Modified Hydrogel Scaffolds.

Scaffolds for the filling and regeneration of osteochondral defects are a current challenge in the biomaterials field, and solutions with greater functionality are still being sought. The novel approach of this work was to obtain scaffolds with biologically active additives possessing microstructural, permeability, and mechanical properties, mimicking the complexity of natural cartilage. Four types of scaffolds with a gelatin/alginate matrix modified with hydroxyapatite were obtained, and the relationship between the modifiers and substrate properties was evaluated. They differed in the type of second modifier used, which was hydrated MgCl2 in two proportions, ZnO, and nanohydroxyapatite. The samples were obtained by freeze-drying by using two-stage freezing. Based on microstructural observations combined with X-ray microanalysis, the microstructure of the samples and the elemental content were assessed. Permeability and mechanical tests were also performed. The scaffolds exhibited a network of interconnected pores and complex microarchitecture, with lower porosity at the surface (15 ± 7 to 29 ± 6%) and higher porosity at the center (67 ± 8 to 75 ± 8%). The additives had varying effects on the pore sizes and permeabilities of the samples. ZnO yielded the most permeable scaffolds (5.92 × 10-11 m2), whereas nanohydroxyapatite yielded the scaffold with the lowest permeability (1.18 × 10-11 m2), values within the range reported for trabecular bone. The magnesium content had no statistically significant effect on the permeability. The best mechanical parameters were obtained for ZnO samples and those containing hydrated MgCl2. The scaffold's properties meet the criteria for filling osteochondral defects. The developed scaffolds follow a biomimetic approach in terms of hierarchical microarchitecture and mechanical parameters as well as chemical composition. The obtained composite materials have the potential as biomimetic scaffolds for the regeneration of osteochondral defects.

Níveis séricos de magnésio, sua associação com diabetes mellitus tipo 2 e suas complicações/comorbidades com enfâse na doença cardiovascular / Serum magnesium levels and their association with type 2 diabetes mellitus and its complications/comorbidites, especially cardiovascular disease / Niveles séricos de magnesio y su asociación con diabetes mellitus tipo 2, sus complicaciones/comorbilidades con énfasis en la enfermedad cardiovascular

O diabetes mellitus tipo 2 (DM2) é uma doença que apresenta mecanismos fisiopatológicos multifatoriais e complexos, tendo como base a resistência insulínica (RI) e como consequências as doenças cardiovasculares (DCV). A hipomagnesemia tem sido implicada tanto na RI como em complicações micro e macrovasculares, incluindo-se as DCV que são consideradas a causa mais importante de morbimortalidade no DM2. Neste contexto, o presente estudo visa avaliar níveis séricos de magnésio (Mg) em pacientes diabéticos e sua possível associação com complicações crônicas e comorbidades, tendo como ênfase as doenças cardiovasculares; e identificar possível valor do nível sérico a ser considerado em nossa população a fim de rever sua verdadeira aplicabilidade clínica. Trata-se de estudo transversal, descritivo e analítico, envolvendo 99 pacientes com DM2 de ambos os sexos, atendidos em ambulatório público na cidade de Salvador (BA). Utilizou-se como instrumentos de pesquisa questionário de dados sociodemográficos e antropométricos; recordatório alimentar de 24 horas e análise bioquímica do magnésio sérico. Também foram registradas comorbidades e complicações crônicas dos pacientes, tais como hipertensão arterial, doença arterial coronariana, doença arterial obstrutiva periférica, arritmia cardíaca, acidente vascular cerebral, dislipidemia, neuropatia sensitiva periférica, retinopatia e nefropatia diabéticas. Os dados foram expressos por tabelas de forma descritiva e analítica. Os indivíduos foram divididos em dois grupos, magnésio baixo e normal/alto, e suas variáveis foram comparadas por meio de testes de hipóteses. Nossos achados evidenciaram nível sérico médio de magnésio de 1,97 mg% (IC 1,69 a 2,25 mg%) no total da amostra. Entre aqueles com magnésio baixo, níveis subclínicos estavam presentes em 29 sujeitos (29,3%), e níveis de hipomagnesemia em 34 indivíduos (34,3%). O nível médio do Mg no total da amostra diferiu significativamente (p<0,001) do valor normal ideal, mas não diferiu do considerado subclínico (p 0,311). No grupo com hipomagnesemia houve predomínio do sexo feminino e de pacientes com maior escolaridade. Glicemia de jejum foi mais elevada no grupo Mg baixo, e hemoglobina glicada no grupo Mg normal/alto, mas ambos sem diferença estatística. Níveis baixos de vitamina B12 foram encontrados em 12 pacientes (12,1%) e os níveis mais baixos de magnésio estavam presentes nos pacientes com deficiência de vitamina B12 (1,81±0,24 versus 2,01±0,29) com p=0,027. Antidiabéticos orais foram mais utilizados no grupo com Mg baixo. Não houve diferença entre magnésio sérico, ingestão calórica e magnésio e cálcio alimentares. Pacientes com DCV tiveram média de 2,01 mg% (IC 1,69-2,33 mg%) para o Mg. A doença cardiovascular esteve presente em 47,5% da amostra e pacientes com esta morbidade apresentaram 29,8% de prevalência de hipomagnesemia; infarto agudo do miocárdio (IAM) foi mais frequente no grupo com Mg normal/alto. Nossos dados apontam que hipomagnesemia em pacientes diabéticos deve ser considerada em níveis clínicos e subclínicos. Níveis baixos de Mg também estiveram associados à vitamina B12 baixa. Pacientes que apresentaram doenças cardiovasculares associadas também tiveram importante prevalência de hipomagnesemia incluindo níveis subclínicos, com exceção nos casos de IAM, em que níveis do magnésio sérico mantiveram-se no intervalo considerado normal ideal evidenciado por significativa diferença estatística (p<0,005).

Diabetes mellitus type 2 (DM2) is a multifactorial disease with complex physiopathological mechanisms, in which insulin resistance (IR) and its consequences, such as cardiovascular diseases (CVD), form its basis. Hypomagnesemia has been implicated in IR and micro and macrovascular complications, including CVD, which is considered the most important cause of morbidity and mortality in DM2. This study aims to evaluate serum magnesium (Mg) levels in diabetic patients and its possible association with chronic complications and comorbidities (especially cardiovascular diseases) and to find a possible serum level value to be considered in its population to review its true clinical applicability. This cross-sectional, descriptive, and analytical study involved 99 DM2 patients of all sexes who were served in a public outpatient clinic in Salvador-Ba. A sociodemographic and anthropometric data questionnaire, a 24-hour food recall, and serum magnesium analysis were used as research instruments. The comorbidities and chronic complications of patients, such as hypertension, coronary artery disease, peripheral arterial obstructive disease, cardiac arrhythmia, cerebrovascular accident, dyslipidemia, peripheral sensory neuropathy, diabetic retinopathy, and nephropathy, were also recorded. The data were expressed in descriptive and analytical tables. The individuals were divided into two groups, low and normal/high magnesium, and their variables were compared using hypothesis tests. Our findings showed an average serum magnesium level of 1.97 mg% (IC 1.69 to 2.25 mg%) in the whole sample. In those with low magnesium, subclinical levels occurred in 29 subjects (29.3%)and hypomagnesemia, in 34 individuals (34.3%). The median Mg level in the total sample significantly differed (p<0.001) from the ideal normal value, but failed to do in relation to the subclinical value (p=0.311). The hypomagnesemia group showed a predominance of women and patients with higher education. Fasting glucose was higher in the low Mg group and glycated hemoglobin in the normal/high Mg group, both without statistical differences. Low levels of vitamin B12 occurred in 12 patients (12.1%) and the lowest magnesium levels, in patients with vitamin B12 deficiency (1.81±0.24 versus 2.01±0.29) (p=0.027). Oral antidiabetics were more used in the group with low Mg. Serum magnesium, caloric intake, and dietetic magnesium and calcium showed no differences. Patients with CVD had an Mg average of 2.01 mg% (IC 1.69-2.33 mg%). Cardiovascular disease occurred in 47.5% of the sample. Patients with this morbidity had a 29.8% prevalence of hypomagnesemia. Moreover, myocardial infarction occurred more often in the normal/high Mg group. Data suggest that hypomagnesemia in diabetic patients should be considered at clinical and subclinical levels. Low Mg levels were also associated with low vitamin B12. Patients who showed cardiovascular diseases also had a high prevalence of hypomagnesemia, including subclinical levels, except in cases of myocardial infarction, in which serum magnesium levels remained within the normal ideal range, as evinced by its significant statistical difference (p<0.005).

La diabetes mellitus tipo 2 (DM2) es una enfermedad con mecanismos fisiopatológicos multifactoriales y complejos caracterizada por la resistencia a la insulina (RI) y sus consecuencias, como las enfermedades cardiovasculares (ECV). La hipomagnesemia está asociada con la RI y las complicaciones micro y macrovasculares, incluyendo las ECV, que se consideran la principal causa de morbimortalidad por la DM2. En este contexto, este estudio tiene como objetivo evaluar los niveles séricos de magnesio (Mg) en pacientes diabéticos y la posible asociación con complicaciones crónicas y comorbilidades, con énfasis en las enfermedades cardiovasculares; e identificar un posible valor de nivel sérico para considerar en esta población con el fin de revisar su verdadera aplicabilidad clínica. Se trata de un estudio transversal, descriptivo y analítico, en el cual participaron 99 pacientes con DM2 de ambos sexos, atendidos en un centro ambulatorio público en la ciudad de Salvador (Bahía, Brasil). Se utilizaron un cuestionario de datos sociodemográficos y antropométricos, un recordatorio alimentario de 24 horas y un análisis bioquímico del magnesio sérico. También se registraron las comorbilidades y complicaciones crónicas de los pacientes, como hipertensión arterial, enfermedad arterial coronaria, enfermedad arterial obstructiva periférica, arritmia cardíaca, accidente cerebrovascular, dislipidemia, neuropatía sensorial periférica, retinopatía y nefropatía diabética. Los datos se dispusieron en tablas para su análisis y descripción. Los individuos se separaron en dos grupos: bajo magnesio y normal/alto magnesio, y se compararon sus variables mediante pruebas de hipótesis. Los hallazgos evidenciaron un nivel sérico medio de magnesio de 1,97 mg% (IC 1,69 a 2,25 mg%) en el total de la muestra. Los bajos niveles subclínicos de magnesio estaban presentes en 29 sujetos (29,3%), y la hipomagnesemia en 34 individuos (34,3%). El nivel medio de Mg en el total de la muestra tuvo una diferencia significativa (p<0,001) del valor normal ideal, pero no difirió del valor subclínico (p=0,311). En el grupo con hipomagnesemia hubo predominio del sexo femenino y de pacientes con mayor nivel de estudios. La glucemia en ayunas fue más alta en el grupo de bajo Mg, y la hemoglobina glucosilada en el grupo de normal/alto Mg, pero en ninguno de los dos se encontró diferencia estadística. Los bajos niveles de vitamina B12 se encontraron en 12 pacientes (12,1%), y los niveles más bajos de magnesio estaban presentes en los pacientes con deficiencia de vitamina B12 (1,81±0,24 versus 2,01±0,29) con p=0,027. Los antidiabéticos orales se utilizaron más en el grupo con bajo Mg. No hubo diferencia entre el magnesio sérico, la ingesta calórica, el magnesio y el calcio en la dieta. Los pacientes con ECV tuvieron una media de 2,01 mg% (IC 1,69-2,33 mg%) para Mg. La enfermedad cardiovascular estuvo presente en el 47,5% de la muestra, y los pacientes con esta morbilidad tuvieron una prevalencia del 29,8% de hipomagnesemia; el infarto agudo de miocardio (IAM) fue más frecuente en el grupo con normal/alto Mg. Los resultados demuestran que la hipomagnesemia en los pacientes diabéticos debe considerarse en los niveles clínicos y subclínicos. Los bajos niveles de Mg también estuvieron asociados a bajos niveles de vitamina B12. Los pacientes que presentaron enfermedades cardiovasculares asociadas también tuvieron una alta prevalencia de hipomagnesemia, incluidos los niveles subclínicos, con excepción de los casos de IAM en los que los niveles séricos de magnesio se mantuvieron dentro del intervalo considerado normal ideal, evidenciado por una diferencia estadísticamente significativa (p<0,005).

Magnesium enhances aurintricarboxylic acid's inhibitory action on the plasma membrane Ca2+-ATPase.

Our research aimed to elucidate the mechanism by which aurintricarboxylic acid (ATA) inhibits plasma membrane Ca2+-ATPase (PMCA), a crucial enzyme responsible for calcium transport. Given the pivotal role of PMCA in cellular calcium homeostasis, understanding how it is inhibited by ATA holds significant implications for potentially regulating physiopathological cellular processes in which this pump is involved. Our experimental findings revealed that ATA employs multiple modes of action to inhibit PMCA activity, which are influenced by ATP but also by the presence of calcium and magnesium ions. Specifically, magnesium appears to enhance this inhibitory effect. Our experimental and in-silico results suggest that, unlike those reported in other proteins, ATA complexed with magnesium (ATA·Mg) is the molecule that inhibits PMCA. In summary, our study presents a novel perspective and establishes a solid foundation for future research efforts aimed at the development of new pharmacological molecules both for PMCA and other proteins.

Unravelling the analgesic effects of perioperative magnesium in general abdominal surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Prior research has established the effectiveness of magnesium in relieving postoperative pain. This article aims to evaluate magnesium sulfate for perioperative analgesia in adults undergoing general abdominal surgery under general anesthesia. OBJECTIVE: The primary aim was to assess pain scores at 6 and 24 hours postoperatively in patients receiving magnesium sulfate vs. the control group. Secondary outcomes were postoperative opioid consumption, perioperative complications, and time to rescue analgesia. METHODS: A comprehensive database search identified studies comparing magnesium sulfate with control in adults undergoing general anesthesia for general abdominal surgery. Using random-effects models, data were presented as mean ± Standard Deviation (SD) or Odds Ratios (OR) with corresponding 95% Confidence Intervals (95% CI). A two-sided p-value < 0.05 was considered statistically significant. RESULTS: In total, 31 studies involving 1762 participants met the inclusion criteria. The magnesium group showed significantly lower postoperative pain scores at both early (within six hours) and late (up to 24 hours) time points compared to the control group. The early mean score was 3.1 ± 1.4 vs. 4.2 ± 2.3, and the late mean score was 2.3 ± 1.1 vs. 2.7 ± 1.5, resulting in an overall Mean Difference (MD) of -0.72; 95% CI -0.99, -0.44; p < 0.00001. The magnesium group was associated with lower rates of postoperative opioid consumption and shivering and had a longer time to first analgesia administration compared to the saline control group. CONCLUSION: Magnesium sulfate administration was linked to reduced postoperative pain and opioid consumption following general abdominal surgery.

(Na+, K+)- ATPase kinetics in Macrobrachium pantanalense: highlighting intra- and interspecific variation within the Macrobrachium amazonicum complex.

The Macrobrachium amazonicum complex is composed of at least the Macrobrachium amazonicum and Macrobrachium pantanalense species, with the latter described from specimens originally identified as part of an endemic M. amazonicum population in the Brazilian Pantanal region. While there may be a reproductive barrier between these two Macrobrachium species, both are phylogenetically close, with small genetic distance. However, there is currently no available biochemical information of Macrobrachium pantanalense (Na+, K+)-ATPase. Here, we report the kinetic characteristics of the gill (Na+, K+)-ATPase in two populations of M. pantanalense from Baiazinha Lagoon (Miranda, MS, Brazil) and Araguari River (Uberlândia, MG, Brazil), and compare them with Macrobrachium amazonicum populations from the Paraná-Paraguay River Basin. (Na+, K+)-ATPase activities were 67.9 ± 3.4 and 93.3 ± 4.1 nmol Pi min-1 mg-1 protein for the Baiazinha Lagoon and Araguari River populations, respectively. Two ATP hydrolyzing sites were observed for the Araguari River population while a single ATP site was observed for the Baiazinha Lagoon shrimps. Compared to the Araguari River population, a 3-fold greater apparent affinity for Mg2+ and Na+ was estimated for the Baiazinha Lagoon population, but no difference in K+ affinity and ouabain inhibition was seen. The kinetic differences observed in the gill (Na+, K+)-ATPase between the two populations of M. pantanalense, compared with those of various M. amazonicum populations, highlight interspecific divergence within the Macrobrachium genus, now examined from a biochemical perspective.

Associations among diabetes medication use, serum magnesium, and insulin resistance in a cohort of older Puerto Rican adults.

BACKGROUND: Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear. OBJECTIVES: We aimed to examine the association between diabetes medication and hypomagnesemia and evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort. METHODS: Adults from the Boston Puerto Rican Health Study were included (n = 1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg <0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-y HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) of ≥6.5%. RESULTS: Mean age at baseline was 59.0 ± 7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: ß (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [ß (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: ß (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones. CONCLUSIONS: Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

Bryophyte-Bioinspired Nanoporous AAO/C/MgO Composite for Enhanced CO2 Capture: The Role of MgO.

A composite material composed of anodized aluminum oxide (AAO), carbon (C), and magnesium oxide (MgO) was developed for CO2 capture applications. Inspired by the bryophyte organism, the AAO/C/MgO composite mirrors two primary features of these species-(1) morphological characteristics and (2) elemental composition-specifically carbon, oxygen, and magnesium. The synthesis process involved two sequential steps: electroanodization of aluminum foil followed by a hydrothermal method using a mixture of glucose and magnesium chloride (MgCl2). The concentration of MgCl2 was systematically varied as the sole experimental variable across five levels-1 mM, 2 mM, 3 mM, 4 mM, and 5 mM-to investigate the impact of MgO formation on the samples' chemical and physical properties, and consequently, their CO2 capture efficiency. Thus, scanning electron microscopy analysis revealed the AAO substrate's porous structure, with pore diameters measuring 250 ± 30 nm. The growth of MgO on the AAO substrate resulted in spherical structures, whose diameter expanded from 15 nm ± 3 nm to 1000 nm ± 250 nm with increasing MgCl2 concentration from the minor to major concentrations explored, respectively. X-ray photoelectron spectroscopy (XPS) analysis indicated that carbon serves as a linking agent between AAO and MgO within the composite. Notably, the composite synthesized with a 4 mM MgCl2 concentration exhibited the highest CO2 capture efficiency, as determined by UV-Vis absorbance studies using a sodium carbonate solution as the CO2 source. This efficiency was quantified with a 'k' constant of 0.10531, significantly higher than those of other studied samples. The superior performance of the 4 mM MgCl2 sample in CO2 capture is likely due to the optimal density of MgO structures formed on the sample's surface, enhancing its adsorptive capabilities as suggested by the XPS results.

Heavy metals bioaccumulation in free-ranging South American rattlesnakes (Crotalus durissus) in Southeastern Brazil.

Anthropogenic activities are the main sources of soil, air, and water pollution by metals, including cadmium (Cd), lead (Pb), chromium (Cr), the metalloid arsenic (As), magnesium (Mg), zinc (Zn), and copper (Cu). The goal of this study was to assess the presence and concentration of toxic (As, Cd, Pb, and Cr) and essential metals (Mg, Zn, and Cu) in the liver and kidneys from 96 free-ranging rattlesnakes (Crotalus durissus) from Minas Gerais (Brazil). Bioaccumulation of Cd and Pb were significantly higher in males and heavier rattlesnakes (those with body weight above the average of the study population). Average ± standard deviations of Cd, Pb, Cr, Cu, Mg, Zn, and As in the general population (n = 96) were 3.19 ± 2.52; 5.98 ± 8.49; 0.66 ± 1.97; 3.27 ± 2.85; 776.14 ± 2982.92; 27.44 ± 29.55; and 0.32 ± 1.46; respectively. Bioaccumulation of some metals correlated positively with changes in hematologic and serum biochemical parameters. Results of this study were contrasted with previous studies assessing metal bioaccumulation in other species of terrestrial or aquatic snakes. Considering their position in the food chain and the broad range of bioaccumulation of both toxic and essential metals observed in this study, rattlesnakes may function as highly relevant biological sentinels for environmental pollution.

Sulfato de magnesio y aminofilina en el tratamiento de niños, niñas y adolescentes hospitalizados. Perfil de uso y respuesta terapéutica

Introducción: Sulfato de magnesio (MgSO4) y aminofilina son broncodilatadores intravenosos utilizados en el tratamiento de niños con broncoobstrucción (BO). La evidencia disponible para recomendar su uso es escasa. Objetivo: Caracterizar el perfil de uso y la respuesta terapéutica al MgSO4 y aminofilina en el tratamiento de la BO en niños hospitalizados en un centro de referencia de Uruguay. Materiales y métodos: Estudio descriptivo de corte transversal mediante revisión de historias y entrevistas. Se incluyeron a todos los menores de 15 años que utilizaron estos fármacos. Se evaluó la respuesta terapéutica a la administración de ambos fármacos en forma exclusiva y concomitante y la presencia de efectos adversos. Resultados: Se incluyeron 102 niños, mediana de edad 4 años, ≤5 años 62%. Los principales diagnósticos fueron: crisis asmática 56% y neumonía viral 31%. Recibieron ambos fármacos 48%, únicamente aminofilina 28% y exclusiva de MgSO4 24%. Se observó buena respuesta terapéutica a la administración: exclusiva de MgSO4 67%, consecutiva de MgSO4 y aminofilina 45% y exclusiva de aminofilina en 34%. En 38,2% se registró al menos un efecto adverso, 64% eran menores de 5 años, riesgo aumentado en 1,5 veces. Conclusiones: Se registraron variadas indicaciones, la mayoría en niños asmáticos y en un porcentaje menor indicaciones fuera de prospecto. Menos de la mitad presentaron buena respuesta luego de la administración de MgSO4 y/o aminofilina. En un porcentaje no despreciable se registraron efectos adversos, predominaron en menores de 5 años. Son necesarios nuevos estudios para continuar caracterizando el perfil de uso y seguridad de estos fármacos.

Introduction: Magnesium sulfate (MgSO4) and aminophylline are intravenous bronchodilators used in the treatment of children with bronchoobstruction (BO). The evidence available to recommend their use is scarce. Objective: To characterize the use profile and therapeutic response to MgSO4 and aminophylline in the treatment of BO in children hospitalized in a reference center in Uruguay. Materials and methods: This was a descriptive cross-sectional study through review of clinical histories and interviews. All children under 15 years of age who used these drugs were included. The therapeutic response to the administration of both drugs exclusively and concomitantly and the presence of adverse effects were evaluated. Results: 102 children were included, median age was 4 years, 62% were ≤5 years. The main diagnoses were: asthmatic crisis, 56% and viral pneumonia, 31%. 48% received both drugs, 28% only aminophylline and 24% exclusively MgSO4. Good therapeutic response was observed to the administration: MgSO4 exclusively, 67%, MgSO4 followed by aminophylline, 45% and aminophylline exclusively in 34%. At least one adverse effect was recorded in 38.2%, of these, 64% were under 5 years of age, risk increased by 1.5 times. Conclusions: Various indications were recorded, the majority in asthmatic children and a smaller percentage off-label indications. Less than half had a good response after the administration of MgSO4 and/or aminophylline. Adverse effects were recorded in a non-negligible percentage, predominating in children under 5 years of age. New studies are necessary to continue characterizing the use and safety profile of these drugs.

Uterotonics, magnesium sulphate and antibiotics during childbirth and peripartum: Important obstetric drugs for the anaesthesiologist.

The main causes of maternal mortality are comorbidities, hypertensive pregnancy syndrome, obstetric haemorrhage, and maternal sepsis. For this reason, uterotonics, magnesium sulphate, and antibiotics are essential tools in the management of obstetric patients during labour and in the peripartum period. These drugs are widely used by anaesthesiologists in all departments, and play a crucial role in treatment and patient safety. For the purpose of this narrative review, we performed a detailed search of medical databases and selected studies describing the use of these drugs in patients during pregnancy, delivery and the pospartum period. Uterotonics, above all oxytocin, play an important role in the prevention and treatment of pospartum haemorrhage, and various studies have shown that in obstetric procedures, such as scheduled and emergency caesarean section, they are effective at lower doses than those hitherto accepted. We also discuss the use of carbetocin as an effective alternative that has a therapeutic advantage in certain clinical circumstances. Magnesium sulphate is the gold standard in the prevention and treatment of eclampsia, and also plays a neuroprotective role in preterm infants. We describe the precautions to be taken during magnesium administration. Finally, we discuss the importance of understanding microbiology and the pharmacology of antibiotics in the management of obstetric infection and endometritis, and draw attention to the latest trends in antibiotic regimens in labour and caesarean section.

Standard medical therapy with vs. without nebulised magnesium for children with asthma decompensation.

Pediatric asthma is a common condition, and its exacerbations can be associated with significant morbidity and mortality. The role of nebulised magnesium as adjunct therapy for children with asthma exacerbations is still unclear. To compare clinical and functional outcomes for children with asthma exacerbation taking either nebulised magnesium sulfate added to standard medical therapy (SMT) versus SMT alone. PubMed, Embase, and Cochrane Library were systematically searched for randomised clinical trials (RCT) comparing the use of SMT with vs. without nebulised magnesium. The outcomes were respiratory rate, heart rate, % predicted peak expiratory flow rate (PEFR), % predicted forced expiratory volume (FEV1), peripheral O2 saturation, asthma severity scores, and need for intravenous (IV) bronchodilator use. Twelve RCTs and 2484 children were included. Mean age was 5.6 (range 2-17) years old, mean baseline % predicted FEV1 was 69.6%, and 28.66% patients were male. Children treated with magnesium had a significantly higher % predicted PEFR (mean difference [MD] 5.33%; 95% confidence interval [CI] 4.75 to 5.90%; p < 0.01). Respiratory rate was significantly lower in the magnesium group (MD -0.70 respirations per minute; 95% CI -1.24 to -0.15; p < 0.01). Need for IV bronchodilators, % predicted FEV1, heart rate, asthma severity scores, and O2 saturation were not significantly different between groups. CONCLUSION: In children with asthma exacerbation, treatment with nebulised magnesium and SMT was associated with a statistically significant, but small improvement in predicted PEFR and respiratory rate, as compared with SMT alone. WHAT IS KNOWN: • Magnesium sulfate has bronchodilating properties and aids in the treatment of asthma exacerbation when administered intravenously. • There is no significant evidence of benefit of nebulised magnesium as an adjunct therapy to the standard medical treatment for children with asthma exacerbations. WHAT IS NEW: • Our study suggests nebulised magnesium sulfate may have a statistically significant, but small benefit in respiratory rate and peak expiratory flow rate. The addition of nebulised magnesium does not seem to increase adverse events.

Emerging therapeutic strategies in hypoxic-ischemic encephalopathy: a focus on cognitive outcomes.

Perinatal hypoxia-ischemia represents a significant risk to CNS development, leading to high mortality rates, diverse damages, and persistent neurological deficits. Despite advances in neonatal medicine in recent decades, the incidence of HIE remains substantial. Motor deficits can manifest early, while cognitive impairments may be diagnosed later, emphasizing the need for extended follow-up. This review aims to explore potential candidates for therapeutic interventions for hypoxic-ischemic encephalopathy (HIE), with a focus on cognitive deficits. We searched randomized clinical trials (RCT) that tested drug treatments for HIE and evaluated cognitive outcomes. The results included studies on erythropoietin, melatonin, magnesium sulfate, topiramate, and a combination of vitamin C and ibuprofen. Although there are several indications of the efficacy of these drugs among animal models, considering neuroprotective properties, the RCTs failed to provide complete effectiveness in the context of cognitive impairments derived from HIE. More robust RCTs are still needed to advance our knowledge and to establish standardized treatments for HIE.