Electron Spin-Dependent Electrocatalysis for the Oxygen Reduction Reaction in a Chiro-Self-Assembled Iron Phthalocyanine Device.

The chiral-induced spin selectivity effect (CISS) is a breakthrough phenomenon that has revolutionized the field of electrocatalysis. We report the first study on the electron spin-dependent electrocatalysis for the oxygen reduction reaction, ORR, using iron phthalocyanine, FePc, a well-known molecular catalyst for this reaction. The FePc complex belongs to the non-precious catalysts group, whose active site, FeN4, emulates catalytic centers of biocatalysts such as Cytochrome c. This study presents an experimental platform involving FePc self-assembled to a gold electrode surface using chiral peptides (L and D enantiomers), i.e., chiro-self-assembled FePc systems (CSAFePc). The chiral peptides behave as spin filters axial ligands of the FePc. One of the main findings is that the peptides' handedness and length in CSAFePc can optimize the kinetics and thermodynamic factors governing ORR. Moreover, the D-enantiomer promotes the highest electrocatalytic activity of FePc for ORR, shifting the onset potential up to 1.01 V vs. RHE in an alkaline medium, a potential close to the reversible potential of the O2 /H2 O couple. Therefore, this work has exciting implications for developing highly efficient and bioinspired catalysts, considering that, in biological organisms, biocatalysts that promote O2 reduction to water comprise L-enantiomers.

Anthracene scaffold as highly selective chemosensor for Al3+ and its AIEE activity.

Fluorescent chemosensor, 3-(Anthracen-2-yliminomethyl)-benzene-1,2-diol (ANB) has been synthesized by one-step condensation of 2-aminoanthracene and 2,3-dihydroxybenzaldehyde and characterized using 1H-NMR, FT-IR and Mass spectroscopic techniques. The probe ANB was found to be an efficient 'turn-on' fluorescence chemosensor for the selective detection of Al3+ ion over other metal ions in an aqueous solution. The chemosensor exhibits ~ 27-fold enhancement of emission intensity in presence of Al3+ ion. Fluorescence quantum values for ANB and (Al3+-ANB)-complex are 0.004 and 0.097, respectively. In addition, the binding constant and the limit of detection were found to be 1.22 × 104 M-1 and 0.391 µM, respectively. The chemosensor ANB binds to Al3+ ions in 2:1 stoichiometric ratio which was supported by Job's plot, 1H-NMR titration and florescence titration. Fluorescence reversibility of the sensor complex was well established by adding EDTA in the same condition and a molecular INHIBIT logic gate was fabricated using this reversible nature of the sensor complex. Additionally, the chemosensor ANB shows a novel aggregation-induced enhanced emission phenomenon, where the aggregate hydrosol of ANB shows enhance emission intensity.

The luminescent Chalcones. Its potential use as a luminescent and antitumoral agents / Chalconas luminiscentes. Su uso potencial como agentes luminiscentes y antitumorales

Background: Hepatocellular carcinoma (HCC) is one of the most diagnosed cancers worldwide. Chemoprevention of HCC can be achieved using natural or synthetic compounds that reverse, suppress, detect, or prevent cancer progression. Objectives: In this study, both the antiproliferative effects and luminescent properties of 2'-hydroxychalcones were evaluated. Methods: Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay, spectroscopy assays, and density functional theory (DFT) calculations were used to determine the luminescent properties of 2 ́-hydroxychalcones. Results: Cytotoxic effects of 2 ́-hydroxychalcones were observed over the HepG2 and EA.hy926 cells. Since the chalcone moiety could be used as a fluorescent probe, these compounds may be helpful in cancer diagnosis and tumor localization. They may enable tumor observation and regression through the fluorescence during treatment; therefore, the compounds are a potential candidate as novel anticancer agents acting on human hepatomas. Conclusions: This report describes the chalcones' use as a specific luminescent biomarker in tumor cells. We also report the cellular uptake of 2'-hydroxychalcones, their cellular distribution, and the mechanisms that may be responsible for their cytotoxic effects

ANTECEDENTES: El carcinoma hepatocelular (CHC) es uno de los cánceres más diagnosticados en todo el mundo. La quimio prevención del CHC se puede lograr utilizando compuestos naturales o sintéticos que reviertan, supriman, detecten o prevengan la progresión del cáncer. OBJETIVOS: En este estudio, se investigó tanto los efectos antiproliferativos como las propiedades luminiscentes de las 2'-hidroxicalconas. MÉTODOS: La viabilidad celular se evaluó usando el ensayo colorimétrico (MTT), los ensayos de espectroscopia y los cálculos DFT se usaron para determinar las propiedades luminiscentes de las 2 ́-hidroxichalconas. RESULTADOS: Se observaron efectos citotóxicos sobre las líneas celulares del tipo HepG2 y EA.hy926. Dado que la estructura de la 2 ́-hidroxichalcona puede ser usada como sonda fluorescente, estos compuestos pueden ser útiles en el diagnóstico del cáncer y la localización del tumor, ya que pueden permitir la observación a través de la fluorescencia y la regresión del tumor durante el tratamiento, por lo que son candidatas potenciales como nuevos agentes anticancerígenos que podrían actuar sobre hepatomas humanos. CONCLUSIONES: Este trabajo describe el uso de las 2 ́-hidroxichalconas como un biomarcador luminiscente específico para células tumorales. También informamos la captación celular de 2>-hidroxicalconas, su distribución celular y los mecanismos que pueden ser responsables de sus efectos citotóxicos

Cluster of Hexamolybdenum [Mo6Cl14]2- for Sensing Nitroaromatic Compounds.

This contribution describes a novel method for the detection of trace amounts of trinitrotoluene (TNT) using a cluster of hexamolybdenum with general formula [Mo6Cl14]2-. The molybdenum cluster was characterized by UV-visible, FT-IR, and fluorescence techniques, and the synthesis was efficient and reproducible. The evaluation of the molybdenum cluster by TNT detection was perfomed by fluoresecent measurements, and the results were interpreted by the Stern-Volmer equation, obtaining K SV values of 2.9 × 105 and 1.6 × 104 M-1 in different concentration ranges. Further, the results suggest that at TNT concentrations higher than 4 × 10-5 mM (0.01 mg L-1) it is possible to measure the quenching of the cluster fluorescence. The DFT calculations indicate that the contribution of the TNT in the active lowest unoccupied molecular orbitals that are involved in the higher intensity transitions in the complex cluster-TNT are significant. This situation differs from all the luminescent [M6X8L6]2- clusters (M = Mo; X = facial bridging ligand, and L = labile axial ligands), where most of the closely spaced excited states are located in the {M6X8} q+ core. Thus, the TNT switches off the cluster luminescence. The approach using a [Mo6Cl14]2--based fluorescence sensor has the potential to be a sensing technology for the detection of nitroaromatic explosives.

[Acute phosphate nephropathy secondary to the use of oral sodium phosphate laxatives. Report of one case]. / Nefropatía aguda por fosfatos secundaria al uso de laxantes con fosfato de sodio: caso clínico-patológico.

Acute phosphate nephropathy (APN) is an acute renal failure secondary to the use of oral sodium phosphate (OSP) laxatives, with a high risk of progression to chronicity. We report a 60-year-old woman with mixed connective tissue disease whose serum creatinine increased up to 2.0 mg/dL in her regular control tests, without an evident causative factor. Kidney biopsy showed numerous intratubular calcium phosphate deposits, consistent with APN. She had a history of OSP laxative intake, and a sodium phosphate enema was used before a colonoscopy performed six months earlier. The temporal association between the use of OSP laxatives and acute kidney injury, should lead to the suspicion of APN. The urine sediment is generally normal or with mild to moderate proteinuria. The diagnosis is confirmed with a kidney biopsy. Until now, there is no specific treatment for APN, thus prevention is essential. In high-risk patients for developing APN, the administration of these laxatives should be avoided.

[A new equation to estimate daily natriuresis from parameters in plasma and spot urine sample in the Chilean population]. / Nueva ecuación para la estimación de la natriuresis diaria a partir de parámetros en plasma y orina aislada en población chilena.

BACKGROUND: Excessive sodium intake is associated with increased cardiovascular morbidity and mortality. Daily sodium intake is usually inferred from sodium excretion in a 24-hour urine collection, which is cumbersome and prone to errors. Different formulas have attempted to estimate 24-hour urinary sodium from a spot urine sample. Unfortunately, their concordances are insufficient and have not been tested in our population. AIM: To develop an equation to predict 24-hour urine sodium from parameters in plasma and spot urine samples. To validate the equation and compare it with other formulas in Chilean population. MATERIAL AND METHODS: Analysis of 24-hour urine collections, plasma sample and spot urine sample from 174 adult outpatients (81% females) with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m2. These were collected between 2015 and 2019 using standardized methods and educating patients about the correct method to collect 24 h urine samples. In all these patients, creatinine and electrolytes were measured in plasma and urine. A new equation was developed using a multiple linear regression model. RESULTS: Twenty-four-hour urine sodium excretion was significantly correlated with age, weight, height, eGFR, plasma osmolarity, urine electrolytes and parameters obtained from spot urine sample, among others. The new equation had a linear correlation with 24-hour natriuresis of 0.91 and the concordance was 0.9. The predictive capacity of the new equation was better than the existing formulas. CONCLUSIONS: We developed a formula to accurately predict daily natriuresis in the Chilean population.

Clinical Presentation and Perioperative Management of Pheochromocytomas and Paragangliomas: A 4-Decade Experience.

PURPOSE: Latin American reports on pheochromocytomas and paragangliomas (PPGLs) are scarce. Recent studies demonstrate changes in clinical presentation and management of these patients. Herein, we assessed the main characteristics of PPGL patients in our academic center over the past 4 decades. METHODS: Demographic, clinical, biochemical, and perioperative data from 105 PPGL patients were retrospectively and prospectively collected over the 1980-2019 period. Data were organized into 4 periods by decade. RESULTS: Age at diagnosis, gender, tumor size and percentage of bilaterality, percentage of paragangliomas, and metastases remained stable across the 4 decades. The proportion of genetic testing and incidentalomas increased in recent decades (all P < 0.001). Therefore, we compared PPGLs diagnosed as incidentalomas (36%) with those clinically suspected (64%). Incidentalomas had fewer adrenergic symptoms (38 vs. 62%; P < 0.001) and lower rates of hypertension (64% vs. 80%; P = 0.01) and hypertensive crisis (28% vs. 44%; P = 0.02); also, they had lower functionality (79% vs. 100%; P = 0.01) and lower catecholamines levels (8.4-fold vs. 12.5-fold above upper cutoffs; P = 0.04). Regarding management of all PPGLs over the decades, we observed significant increases in both perioperative doxazosin dose (P = 0.003) and laparoscopic approach rates (P < 0.001), along with a decrease in the length of hospital stays (P = 0.007). CONCLUSIONS: We observed a change in the clinical presentation of PPGL in recent decades, with a marked increase in incidental cases and milder symptoms. The implementation of a multidisciplinary program for adrenal disorders in our institution has translated into more timely diagnoses, more genetic testing, and improvements in perioperative management.

[Use of cystatin C to estimate glomerular filtration rate]. / Uso de la cistatina C como biomarcador para estimar la tasa de filtración glomerular.

Glomerular filtration rate (GFR) is routinely estimated using endogenous biomarkers due to the complexity of direct measurement methods. Cystatin C is a protease inhibitor produced in all nucleated cells. It is freely filtered and then catabolized by renal tubular cells. Therefore, plasma concentration of cystatin C depends primarily on GFR. Serum cystatin C is less affected by muscle mass, diet, race, gender and age than creatinine. In the general population, equations to estimate GFR based on cystatin C do not have a better performance than those based on creatinine. However, formulas that combine creatinine and cystatin C are more accurate and precise. Estimation of GFR based on cystatin C could be useful in populations in which creatinine value may be biased, such as people with extremely low or high muscle mass, cirrhosis and chronic cardiorenal syndrome. Due to its higher cost in comparison to creatinine, we recommend measuring cystatin C on these clinical situations and when a more accurate estimation of GFR is required.

Nefropatía aguda por fosfatos secundaria al uso de laxantes con fosfato de sodio: caso clínico-patológico / Acute phosphate nephropathy secondary to the use of oral sodium phosphate laxatives: report of one case

Acute phosphate nephropathy (APN) is an acute renal failure secondary to the use of oral sodium phosphate (OSP) laxatives, with a high risk of progression to chronicity. We report a 60-year-old woman with mixed connective tissue disease whose serum creatinine increased up to 2.0 mg/dL in her regular control tests, without an evident causative factor. Kidney biopsy showed numerous intratubular calcium phosphate deposits, consistent with APN. She had a history of OSP laxative intake, and a sodium phosphate enema was used before a colonoscopy performed six months earlier. The temporal association between the use of OSP laxatives and acute kidney injury, should lead to the suspicion of APN. The urine sediment is generally normal or with mild to moderate proteinuria. The diagnosis is confirmed with a kidney biopsy. Until now, there is no specific treatment for APN, thus prevention is essential. In high-risk patients for developing APN, the administration of these laxatives should be avoided.

Nueva ecuación para la estimación de la natriuresis diaria a partir de parámetros en plasma y orina aislada en población chilena / A new equation to estimate daily natriuresis from parameters in plasma and spot urine sample in the Chilean population

Background: Excessive sodium intake is associated with increased cardiovascular morbidity and mortality. Daily sodium intake is usually inferred from sodium excretion in a 24-hour urine collection, which is cumbersome and prone to errors. Different formulas have attempted to estimate 24-hour urinary sodium from a spot urine sample. Unfortunately, their concordances are insufficient and have not been tested in our population. Aim: To develop an equation to predict 24-hour urine sodium from parameters in plasma and spot urine samples. To validate the equation and compare it with other formulas in Chilean population. Material and Methods: Analysis of 24-hour urine collections, plasma sample and spot urine sample from 174 adult outpatients (81% females) with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m2. These were collected between 2015 and 2019 using standardized methods and educating patients about the correct method to collect 24 h urine samples. In all these patients, creatinine and electrolytes were measured in plasma and urine. A new equation was developed using a multiple linear regression model. Results: Twenty-four-hour urine sodium excretion was significantly correlated with age, weight, height, eGFR, plasma osmolarity, urine electrolytes and parameters obtained from spot urine sample, among others. The new equation had a linear correlation with 24-hour natriuresis of 0.91 and the concordance was 0.9. The predictive capacity of the new equation was better than the existing formulas. Conclusions: We developed a formula to accurately predict daily natriuresis in the Chilean population.

Uso de la cistatina C como biomarcador para estimar la tasa de filtración glomerular / Use of cystatin C to estimate glomerular filtration rate

Glomerular filtration rate (GFR) is routinely estimated using endogenous biomarkers due to the complexity of direct measurement methods. Cystatin C is a protease inhibitor produced in all nucleated cells. It is freely filtered and then catabolized by renal tubular cells. Therefore, plasma concentration of cystatin C depends primarily on GFR. Serum cystatin C is less affected by muscle mass, diet, race, gender and age than creatinine. In the general population, equations to estimate GFR based on cystatin C do not have a better performance than those based on creatinine. However, formulas that combine creatinine and cystatin C are more accurate and precise. Estimation of GFR based on cystatin C could be useful in populations in which creatinine value may be biased, such as people with extremely low or high muscle mass, cirrhosis and chronic cardiorenal syndrome. Due to its higher cost in comparison to creatinine, we recommend measuring cystatin C on these clinical situations and when a more accurate estimation of GFR is required.

Urinary sodium-to-potassium ratio and body mass index in relation to high blood pressure in a national health survey in Chile.

Several lifestyle and sociodemographic factors are associated with blood pressure (BP). The authors conducted a retrospective study of 4870 subjects from the National Health Survey 2009 in Chile to identify exposure factors associated with increasing BP levels. Subjects with isolated urinary excretion of sodium (n = 2873), potassium, and creatinine were included to estimate daily salt intake and urinary sodium/potassium (Na/K) ratio. Hypertension was defined according to European guidelines 2018 and American guidelines ACC/AHA 2017. Proportional odds models were developed to analyze education level, sedentarism, smoking, alcohol intake, estimated urinary Na/K ratio, estimated daily salt intake, and body mass index (BMI) as factors associated with increasing BP levels (from high-normal BP to hypertension). Logistic regression models were checked for overdispersion. Mean age and BMI of the population were 42 years old and 27 kg/m2 , respectively; 19% had low education level and 27% had hypertension according to European guidelines, whereas 47% according to ACC/AHA criteria. Mean estimated urinary Na/K ratio was 4 ± 2, and mean salt consumption was 10 ± 2 g/day. Estimated urinary Na/K ratio (OR, 1.11; 95% CI, 1.01-1.21), BMI (OR, 1.10; 95% CI, 1.07-1.13), estimated daily salt intake (OR, 1.10; 95% CI, 1.03-1.17), and alcohol intake (OR, 1.03; 95% CI, 1.01-1.05) were significantly associated with hypertension. This study highlights that a healthy diet and weight control should be important components of BP management plans, and it suggests that public policies should include close monitoring of these factors to reduce hypertension prevalence and improve its management in a Latino population.

Cetoacidosis por estrés: caso clínico en paciente con atrofia muscular espinal / Stress induced ketoacidosis in spinal muscular atrophy: report of one case

Spinal muscular atrophy is an uncommon cause of ketoacidosis, where there is a decrease in muscle mass, an abnormal metabolism of glucose and fatty acids, and changes in neuroendocrine function. These conditions favor the accumulation of keto acids and the development of metabolic acidosis. We report a 26-year-old female, with a history of spinal muscular atrophy type III, consulting for abdominal pain and vomiting lasting one week. She was admitted to the emergency service somnolent and poorly perfused. She had a pH of 6.98, HCO3- of 3.8 mmol/L, pCO2 of 16.4 mmHg, BE of -26 mmol/L, delta ratio of 1.05, anion gap of 31 mEq/L, creatinine of 0.37 mg/dL, sodium of 147 mEq/L, potassium of 3.7 mEq/L, chloride of 112 mEq/L, lactate of 1.2 mmol/L, glucose of 108 mg/dL, albumin of 4.2 g/dL, ketonemia +++, ketonuria +, measured plasma osmolality of 322 mOsm/kg, estimated osmolality of 314 mOsm/kg, toxilab negative, salicylate levels < 3 µg/mL, acetaminophen levels < 1.2 µg/mL. Intravenous hydration and bicarbonate were started, without satisfactory response. Interpreting the clinical picture as a ketoacidosis induced by stress in a patient with spinal muscular atrophy, it was handled with glucose, amino acids, vitamins and trace elements, with a favorable response.

[Stress induced ketoacidosis in spinal muscular atrophy. Report of one case]. / Cetoacidosis por estrés: caso clínico en paciente con atrofia muscular espinal.

Spinal muscular atrophy is an uncommon cause of ketoacidosis, where there is a decrease in muscle mass, an abnormal metabolism of glucose and fatty acids, and changes in neuroendocrine function. These conditions favor the accumulation of keto acids and the development of metabolic acidosis. We report a 26-year-old female, with a history of spinal muscular atrophy type III, consulting for abdominal pain and vomiting lasting one week. She was admitted to the emergency service somnolent and poorly perfused. She had a pH of 6.98, HCO3- of 3.8 mmol/L, pCO2 of 16.4 mmHg, BE of -26 mmol/L, delta ratio of 1.05, anion gap of 31 mEq/L, creatinine of 0.37 mg/dL, sodium of 147 mEq/L, potassium of 3.7 mEq/L, chloride of 112 mEq/L, lactate of 1.2 mmol/L, glucose of 108 mg/dL, albumin of 4.2 g/dL, ketonemia +++, ketonuria +, measured plasma osmolality of 322 mOsm/kg, estimated osmolality of 314 mOsm/kg, toxilab negative, salicylate levels < 3 µg/mL, acetaminophen levels < 1.2 µg/mL. Intravenous hydration and bicarbonate were started, without satisfactory response. Interpreting the clinical picture as a ketoacidosis induced by stress in a patient with spinal muscular atrophy, it was handled with glucose, amino acids, vitamins and trace elements, with a favorable response.

Intoxicación por etilenglicol, fisiopatología y enfrentamiento clínico / Ethylene glycol poisonin: an update

Toxic alcohols can produce severe poisoning with multiple organic involvement and even death. The most common form is ethylene glycol. The diagnosis can be extremely difficult if there is no history of its consumption. Its clinical presentation can simulate other conditions. Ethylene glycol poisoning is characterized by an initial rise in plasma osmolal gap that decreases during the evolution, while alcohol is metabolized to acids. This last condition causes a metabolic acidosis with elevated anion gap. The clinical manifestations are diffuse neurological involvement initially, followed by hemodynamic alterations due to myocardial damage associated with hypocalcemia and acidemia. Subsequently, severe tubular renal damage appears, which may require renal replacement therapy, and finally, focal neurological alterations. To treat this poisoning, it is necessary to inhibit the transformation of alcohol into acids, increase the metabolism of the latter or withdraw them directly with hemodialysis.

Imogolite Synthetized in Presence of As(III) Induces Low Cell Toxicity and Hemolysis, in Vitro, Potential Stabilization of Arsenite Present in Aqueous Systems.

Imogolite is a nanotubular aluminosilicate that has low toxicity in biological systems and due to its morphological and surface properties has a growing interest in environmental applications and biomedical areas. Its synthesis is highly sensitive to the presence of other ions, being able to inhibit or retard the process of imogolite formation, which could change the cytotoxic response of this substrate, something scarcely reported in the literature. In this context, the presence of arsenite during the synthesis of imogolite caused significant changes in the dimensions and surface behavior of these nanotubes. Cell viability was evaluated on EA.hy926 and HepG2 cells by (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay at 24 h. Meanwhile, the potential effects on human red blood cells, namely, hemolysis and morphological changes, were determined at 0 and 24 h. The range of % As tested of the nanotube showed cell toxicity similar to the control condition. Similarly, the As-based nanotubes induced hemolysis similar to controls and slight morphological changes of red blood cells at 0 and 24 h of exposition. These results indicate that As-based imogolite-like nanotubes are not toxic nor hemolytic and can be potentially used in processes like water purification.

[Recurrence of goodpasture syndrome with negative antiglomerular basement antibodies. Report of one case]. / Recurrencia de Síndrome de Goodpasture con negativización de anticuerpos anti-membrana basal glomerular: Caso clínico.

Goodpasture Syndrome is described as a single episode disease entity. It is diagnosed with the demonstration of antiglomerular basement (anti-GBM) antibodies in plasma or renal tissue. Although the recurrence of anti-GBM disease is rare, it has been reported in up to 3% of cases. Recurrence with negative anti-GBM antibodies in plasma is even less frequent We report a 63 years old male in whom anti-GBM disease recurred without detectable anti-GBM antibodies in plasma, despite having positive antibodies at the onset.

Synthesis and characterization of zeolite-based composites functionalized with nanoscale zero-valent iron for removing arsenic in the presence of selenium from water.

We studied the sorption of As(V) in single and multi-component (As(V)-Se(VI)) aqueous systems using nanoscale zero-valent iron (nZVI) and nZVI-functionalized zeolite (Z-nZVI) adsorbents. Morphological and physico-chemical characterization of the adsorbents was conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area and electrophoretic mobility measurements. SEM and XRD analyses showed that Fe-nanoparticle size and crystallinity were better preserved in Z-nZVI than nZVI after As(V) sorption. Highly efficient As(V) removal was achieved for all tested adsorbents with a minimal competition effect of Se(VI). In the single-component system, the equilibrium As(V) sorption time on nZVI and Z-nZVI was 40 and 60 min, respectively, while in the multi-component system, this time was 90 min for both the adsorbents. The Freundlich and pseudo-second-order models provided good fittings for the experimental sorption data (r2>0.96). The As(V) removal capacity was higher using Z-nZVI than nZVI both in the single and multi-component systems, suffering minimal differences in removal in both cases. The results suggested that Z-nZVI had more specific surface sites for As(V) than nZVI and zeolite, which makes Z-nZVI a more effective adsorbent than nZVI for the removal of As(V) from aqueous solutions in the presence of other oxyanions.