Biomineralization of lithium nanoparticles by Li-resistant Pseudomonas rodhesiae isolated from the Atacama salt flat

BACKGROUND: The Atacama salt flat is located in northern Chile, at 2300 m above sea level, and has a high concentration of lithium, being one of the main extraction sites in the world. The effect of lithium on microorganism communities inhabiting environments with high concentrations of this metal has been scarcely studied. A few works have studied the microorganisms present in lithium-rich salt flats (Uyuni and Hombre Muerto in Bolivia and Argentina, respectively). Nanocrystals formation through biological mineralization has been described as an alternative for microorganisms living in metal-rich environments to cope with metal ions. However, bacterial lithium biomineralization of lithium nanostructures has not been published to date. In the present work, we studied lithium-rich soils of the Atacama salt flat and reported for the first time the biological synthesis of Li nanoparticles. RESULTS: Bacterial communities were evaluated and a high abundance of Cellulomonas, Arcticibacter, Mucilaginibacter, and Pseudomonas were determined. Three lithium resistant strains corresponding to Pseudomonas rodhesiae, Planomicrobium koreense, and Pseudomonas sp. were isolated (MIC > 700 mM). High levels of S2− were detected in the headspace of P. rodhesiae and Pseudomonas sp. cultures exposed to cysteine. Accordingly, biomineralization of lithium sulfide-containing nanomaterials was determined in P. rodhesiae exposed to lithium salts and cysteine. Transmission electron microscopy (TEM) analysis of ultrathin sections of P. rodhesiae cells biomineralizing lithium revealed the presence of nanometric materials. Lithium sulfide-containing nanomaterials were purified, and their size and shape determined by dynamic light scattering and TEM. Spherical nanoparticles with an average size < 40 nm and a hydro-dynamic size ~ 44.62 nm were determined. CONCLUSIONS: We characterized the bacterial communities inhabiting Li-rich extreme environments and reported for the first time the biomineralization of Li-containing nanomaterials by Li-resistant bacteria. The biosynthesis method described in this report could be used to recover lithium from waste batteries and thus provide a solution to the accumulation of batteries.

Inducción de trabajo de parto en pacientes COVID-19: experiencia en el Hospital San Juan de Dios / Labor induction in COVID-19 patients: experience in the San Juan de Dios Hospital

INTRODUCCIÖN Y OBJETIVOS: Describir la experiencia de los partos en gestantes con diagnóstico confirmado de COVID 19 mediante RT-PCR asintomáticas o con sintomatología leve y aquellas sin la enfermedad, y determinar la tasa de éxito de parto vaginal en inducción de trabajo de parto. MÉTODOS: Análisis retrospectivo de pacientes que tuvieron su parto entre 15 de Abril y 03 de Julio del 2020 en el Hospital San Juan de Dios. Se incluyeron las pacientes inducidas con Dinoprostona, Oxitocina o ambas de manera secuencial y se dividieron según estatus COVID 19 mediante RT-PCR al ingreso. Se caracterizó demográficamente el grupo de pacientes positivas y se determinaron los datos de ambos grupos en relación a la necesidad de inducción de trabajo de parto y su éxito para parto vaginal. RESULTADOS: De un total de 657 nacimientos, hubo un 9.7% (n=64) de pacientes con COVID 19, de las cuales un 23.4% (n=15) requirió inducción de trabajo de parto, con una tasa de éxito para parto vaginal de un 66.7% (n=10). De estas pacientes, un 50% recibió Oxitocina, un 40% Dinosprostona y un 10% ambos medicamentos de forma secuencial. En las pacientes negativas, hubo un total de 568 nacimientos, con un 29.8% (n=169) de usuarias que requirieron inducción. La tasa de éxito para parto vaginal en este grupo fue de 72.2% (n=122), utilizando un 50% Oxitocina; un 27% Dinoprostona; un 14.8% ambas; y un 8.2% Balón de Cook. CONCLUSIONES: Sabemos que los resultados de este estudio están limitados por el bajo número de pacientes incluidas, sin embargo, podemos observar que, en nuestra experiencia con las pacientes que arrojaron PCR SARS-CoV-2 positivas, asintomáticas o con enfermedad leve, se logró realizar la inducción de trabajo de parto según protocolos habituales, obteniendo porcentajes de éxito para partos vaginales, similares a las pacientes sin la enfermedad.

INTRODUCTION AND OBJECTIVES: Describe the experience of deliveries in pregnant women with a confirmed diagnosis of COVID 19 by asymptomatic RT-PCR or with mild symptoms and those without the disease, and determine the success rate of vaginal delivery in the induction of labor. METHODS: Retrospective study of patients who had their delivery between 15th April and 03rd of July, 2020 in the San Juan de Dios Hospital. Patients induced with Dinoprostone, Oxytocin or both sequentially were included, and were divided according to COVID 19 status by RT-PCR on their admission process. The group of positive patients was demographically characterized and the data of both groups was determined in relation to the need for labor induction and its success for vaginal delivery. RESULTS: Of a total of 657 births, there were 9.7% (n = 64) of patients with COVID 19, of which 23.4% (n = 15) required labor induction, with a success rate for vaginal delivery of 66.7% (n = 10). Of these patients, 50% received Oxytocin, 40% Dinosprostone and 10% both drugs sequentially. In the negative patients, there were a total of 568 births, with 29.8% (n = 169) of users requiring labor induction. The success rate for vaginal delivery in this group was 72.2% (n = 122); 50% using Oxytocin; 27% Dinoprostone; 14.8% using both; and 8.2% using Cook's Catheter. CONCLUSIONS: We know that the results of this study are limited by the low number of patients included, however, in our experience, we can observe that, in patients with SARS-CoV-2 PCR positive, asymptomatic or with mild disease, it was possible to perform induction of labor according to standard protocols, achieving success rates for vaginal deliveries, similar to patients without the disease.

Effect of L-carnitine on exercise performance in patients with mitochondrial myopathy

Exercise intolerance due to impaired oxidative metabolism is a prominent symptom in patients with mitochondrial myopathy (MM), but it is still uncertain whether L-carnitine supplementation is beneficial for patients with MM. The aim of our study was to investigate the effects of L-carnitine on exercise performance in MM. Twelve MM subjects (mean age±SD=35.4±10.8 years) with chronic progressive external ophthalmoplegia (CPEO) were first compared to 10 healthy controls (mean age±SD=29±7.8 years) before they were randomly assigned to receive L-carnitine supplementation (3 g/daily) or placebo in a double-blind crossover design. Clinical status, body composition, respiratory function tests, peripheral muscle strength (isokinetic and isometric torque) and cardiopulmonary exercise tests (incremental to peak exercise and at 70% of maximal), constant work rate (CWR) exercise test, to the limit of tolerance [Tlim]) were assessed after 2 months of L-carnitine/placebo administration. Patients with MM presented with lower mean height, total body weight, fat-free mass, and peripheral muscle strength compared to controls in the pre-test evaluation. After L-carnitine supplementation, the patients with MM significantly improved their Tlim (14±1.9 vs 11±1.4 min) and oxygen consumption ( V ˙ O 2 ) at CWR exercise, both at isotime (1151±115 vs 1049±104 mL/min) and at Tlim (1223±114 vs 1060±108 mL/min). These results indicate that L-carnitine supplementation may improve aerobic capacity and exercise tolerance during high-intensity CWRs in MM patients with CPEO.

Efectos pleiotrópicos de las estatinas: [revisión] / Pleiotropic effects of statins: [review]

Results of numerous epidemiologic studies indicate that elevated serum cholesterol, especially the LDL fraction, is a major cause of coronary heart disease (CHD). Epidemiologic and angiographic evidence from primary and secondary prevention studies involving several HMG-CoA reducíase inhibitors (statins) indicate that decreasing elevated serum cholesterol concentration (specifically LDL-cholesterol) can reduce the incidence of CHD and/or progression of atherosclerosis and results in a decrease in associated morbidity and mortality. It has been estimated that each 1 percent reduction in LDL-cholesterol concentration may result in a 1 percent decrease in the incidence of CHD. Furthermore, an analysis of pooled data from primary and secondary prevention studies found that treatment with a statin for a median duration of 5.4 years was associated with a 31 percent and 21 percent reduction in the risk of major coronary events and total mortality, respectively. This paper deals with the pharmacology of statins, specially with the pleiotropic effects ofthese drugs.

Resistencia antimicrobiana y producción de betalactamasa de Neisseria gonorrhoeae / Antimicrobial resistance and betalactamase production of neisseria gonorrhoeae

Se determinó la susceptibilidad antimicrobiana de 80 cepas de Neisseria gonorrhoeae aisladas de secreciones uretrales obtenidas de pacientes masculinos atendidos en la consulta de enfermedades de transmisión sexual del Ambulatorio Francisco Gómez Padrón, entre Junio de 199 y Abril de 2000. La CIM para penicilina, ofloxacina, ciprofloxacina y azitromicina fue determinada por el método de E-test. La susceptibilidad a ceftriaxona fue determinada a 70 cepas por el metodo de dilución en agar. Todas las cepas fueron probadas por la producción de enzima betalactamasa mediante el método de la cefalosporina cromogénica (Nitrocefinasa). El 31.25 por ciento de las cepas fue resistente a penicilina /CIMs mayor igual 2 µg/mL) y todas ellas fueron productoras de betalactamasa. El 98.75 por ciento se mostró sensible a ofloxacina y ciprofloxacina (CIMs de menor igual 0.19 µg/mL y menor igual 0.064 µg/mL, respectivamente); el 1.25 por ciento presentó susceptibilidad intermedia a estos antimicrobianos (CIMofx=0,50 µg/mL y CIMcip=0,125 µg/mL). Para azitromicina la sensibilidad fue del 97.5 por ciento (CIMs fueron menor igual 0,05 µg/mL) y la resistencia de 2.5 por ciento (CIMs=4 µg/mL). El 100 por ciento de las cepas fue sensible a ceftriaxona (CIMs menor igual 0,016 µg/mL). El desarrollo de resistencia a agentes antimicrobianos de uso frecuente en la práctica médica, hace mantener la vigilancia de los patrones de susceptibilidad en Neisseria gonorrhoeae.