Design to Purify Environments of Microorganisms: Prospects For The Emergence of Covid19

The emergence of Covid 19 has led societies to consider strategies to reduce the probability of contagion in closedenvironments or places with human traffic. One strategy usually considered in laboratories to avoid contaminationis the use of ultraviolet radiation light. UV light acts on the structure of DNA/RNA introducing alterations thatlead to non-functional cellular products (Herman et al. 2021; Valuntaitė and Girg?dienė 2010; Dėdelienė andJuknys 2010; Prasad et al. 2011; Tan and Linskey 2011; Enwemeka et al. 2020). On this basis we decided tomake the following conjecture: if an air stream within an environment is forced to circulate while being irradiatedby UV light it is plausible that the treated air is found to be mitigated in the percentage of particles with functionalgenetic material e.g. bacteria, yeasts and, fungi.The working hypothesis is as follows:Initial air (high cfu) −−−→ Final air (low cfu)↑ UV lightThe equipment should be placed in a space where the light does not radiate directly to people, such as corners,under furniture, etc.Fil: Camacho, María Isabel. No especifíca;Fil: Burgos, Hilda Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Chapela, Sebastián Pablo. Hospital Británico de Buenos Aires; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Serum reactive oxygen species and apoptosis markers in septic patients

Background: Oxidative stress is one of the pathophysiological processes that occur during sepsis. Reactive oxygen species (ROS) production causes lipid peroxidation and protein and DNA damage. ROS and DNA damage triggers apoptosis. Several studies have shown that organ failure in sepsis is mediated by apoptosis. The aim of this study is to investigate the levels of serum ROS and serum caspase-3 in septic patients and healthy volunteers, and their correlation. Methods: Serum samples were taken within the first 12 hours of ICU stay. The dichlorofluorescein technique was used to determine serum ROS levels, and the ELISA technique was used to quantify serum caspase-3 in septic patients and healthy volunteers. Results: There was no difference in serum ROS levels between healthy volunteers and septic patients (P = 0.26), and there was a significant difference in serum caspase-3 levels between healthy volunteers and septic patients (P < 0.001). There was no difference between patients who lived and died in the intensive care unit (ICU) in serum ROS (P = 0.089) and serum caspase-3 (P = 0.18). There was no correlation between both markers (R =-0.0013, P = 0.98). Conclusions: We conclude that there is no correlation between serum ROS and caspase-3; therefore, both processes might not be associated during the first hours of ICU stay.Fil: Chapela, Sebastián Pablo. Hospital Británico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Burgos, Hilda Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Schiel, Amalia. Hospital Británico de Buenos Aires; ArgentinaFil: Alonso, Manuel. Universidad de Buenos Aires; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Determination of the pKa value of phenolphthalein by means of absorbance measurements

We here report a laboratory protocol for the determination of the pKa value of an acid by means of determinations obtained with a spectrophotometer. Students determine the acidity constant (Ka) and the pKa associated with phenolphthalein from the absorbance values obtained from phenolphthalein solutions at different pHs. The present protocol for the determination of the pKa takes a very short time and is useful when teaching in conditions with limited equipment.Fil: Alonso, Manuel. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Chapela, Sebastián P.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Cristaldo, María L.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Nievas, Inés. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Burgos Oliver Gamondi, Hilda I.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Stella, Carlos Alberto. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

N-acetylcysteine increases creatinine levels without lowering reactive oxygen species levels

En la sepsis se activa la cascada in amatoria y se desencadenan múltiples procesos siopatológicos. Uno de esos procesos es la producción de especies reactivas de oxígeno (ROS). Se han descrito diferentes fármacos, como la N-acetilcisteína (NAC), para reducir los niveles de ROS, pero ningún trabajo ha avalado su uso en la sepsis. Este estudio investigó la relación entre ROS y daño renal, generalmente presente en la sepsis, y su posible tratamiento con NAC en ratas. Se utilizaron ratas Sprague Dawley machos. Los animales se dividieron en dos grupos, uno recibió 150 mg/kg de NAC y el otro no. Además, cada grupo se dividió en 4 subgrupos (control, laparotomía, sepsis y sepsis y NAC). Se midieron la creatinina sérica y las ROS. Los subgrupos sépticos tuvieron niveles más altos de ROS que los controles y NAC no disminuyó esos niveles. No hubo diferencias en los niveles de ROS entre los subgrupos (tratados y no tratados con NAC), pero los niveles de creatinina fueron más altos. Se observó una correlación débil entre ROS y los niveles de creatinina y la administración de NAC fue un factor independiente para aumentar los niveles de creatinina. Se observó una correlación entre los niveles de ROS y la creatinina. NAC no redujo los niveles de ROS, pero aumentó los niveles de creatinina. Concluimos que la administración de NAC no mejoró los niveles de ROS y disminuyó la función renal en ratas sépticas. Hubo una correlación débil entre ROS y los niveles de creatinina, lo que demuestra que otros factores pueden modi car la función renal, como la administración de NAC, que fue un factor independiente para la disminución de la función renal medida por la creatinina sérica.In sepsis, the entire in ammatory cascade is activated and multiple pathophysiological processes are triggered. One such process is the production of reactive oxygen species (ROS). Different drugs, such as N-acetylcysteine (NAC), have been described to reduce ROS levels, but no work has endorsed their use in sepsis. This study investigated the relationship between ROS and renal damage usually present in sepsis and its possible treatment with NAC in rats. Male Sprague Dawley rats were used. The animals were divided into two groups, one received 150 mg/kg of NAC and the other did not. In addition, each group was divided into 4 subgroups (control, laparotomy, sepsis, and sepsis and NAC). Serum creatinine and ROS were measured. The septic subgroups had higher levels of ROS than controls and NAC did not decrease those levels. There was no difference in ROS levels between subgroups (treated and not treated with NAC), but creatinine levels were higher. A weak correlation was observed between ROS and creatinine levels and NAC administration was an independent factor for increasing levels of creatinine. A correlation was observed between ROS levels and creatinine. NAC did not lower ROS levels but increased creatinine levels. We conclude that the administration of NAC did not improve ROS levels and decreased kidney function in septic rats. There was a weak correlation between ROS and creatinine levels, showing that other factors can modify kidney function, such as NAC administration which was an independent factor for decreasing renal function measured by serum creatinine.Fil: Chapela, Sebastián Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Burgos, Hilda Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Muryan, Alexis. Hospital Británico de Buenos Aires; ArgentinaFil: Ricart, María Cecilia. Universidad de Buenos Aires; ArgentinaFil: Alonso, Manuel. Universidad de Buenos Aires; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Euglycemic Diabetic Ketoacidosis in the ICU: 3 Case Reports and Review of Literature

Diabetic ketoacidosis (DKA) is an acute complication of diabetes mellitus, both type I and type II, as well as other types with diabetes such gestacional diabetes mellitus. It is characterized by blood glucose levels greater than 250 mg/dL and metabolic acidosis (pH < 7.3 and serum bicarbonate < 15 mEq/dL) with an increased anion gap and the presence of ketone bodies in the blood or urine. Within this pathology, there is a subgroup of pathologies which are characterized by being present with no signs of hyperglycemia, posing a diagnostic challenge due to the absence of the main sign of the pathology and the diversity of their pathophysiology. In this article, we will present 3 clinical cases with 3 different forms of clinical presentation: a case of DKA in pregnancy, a case of DKA associated with the use of sodium-glucose cotransporter 2 (SGLT-2) inhibitors, and a third case related to sepsis, together with a narrative review of the literature on the topic

N-Acetyl cysteine improves cellular growth in respiratory-deficient yeast

Background: Reactive oxygen species (ROS) is a main factor that alters cellular physiology and functionality. Many strategies are used in order to control excessive oxidative stress. One strategy includes the use of antioxidants like N-acetyl cysteine (NAC). The aim of this study was to compare the effect of this antioxidant on ROS production and cellular growth of a wild-type and a respiratory-deficient Saccharomyces cerevisiae strain. Methods: Using a simple system such as yeast allows oxidative stress investigations on which numerous factors are more manageable or circumscribed than in a higher organism. We grew cells in a complex medium and incubated them during 72 h. Later, cellular viability and ROS production was evaluated. ROS level was estimated by use of fluorescence signal with 2′,7′-dichlorofluorescein diacetate (DCFH-DA). Results: As it is found in the present work, a reducing environment exerted by NAC presence during incubation of the cells allows a respiratory-deficient Saccharomyces cerevisiae strain to improve its cellular growth. Conclusions: It seems likely that the energy production or the phenotype which characterizes a deficient strain is incapable of palliating ROS growth inhibition while NAC helps to overcome this limitation.Fil: Chapela, Sebastián P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina. Hospital Británico de Buenos Aires; ArgentinaFil: Burgos, Hilda Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Ischemia - Reperfusion: A look from yeast mitochondria

The apoptotic phenomena observed in tissues which are subdued to ischemia and then to technical therapeutics of perfusion keep causing serious problems in the patient´s clinical recovery. Then, they constitute a challenge to resolve. The objective of this work is to discuss the intracellular mechanisms that lead cells to apoptosis during the ischemia-reperfusion process, taking into consideration that these phenomena are observable in a simple microorganism as the yeast Saccharomyces cerevisiae. Yeast provide an alternative study system in which the effects of certain cytoprotective drugs can be evaluated. The results can then be extrapolated to other types of cells. Several works have focused on the role of mitochondria in the apoptotic processes of cellular necrosis. One of the main factors responsible for this process is the unregulated opening of the permeability barrier. The inner membrane thus allows the unrestricted passage of ions and the release of apoptotic mediators from the inner membrane space towards the cytosol. Also, there is an increase in the level of reactive oxygen species (ROS) and the uncoupling of oxidative phosphorylation, which lead to the reversal of ATP synthesis to ATP hydrolysis. The driving cause of this complex process is the opening of an non-specific pore located in the mitochondrial membrane, denominated mammalian permeability transition pore (mPTP), which is also expressed in yeast (yPTP). From the functional point of view, the yeast pore presents some of the characteristics observed in mammals, and is similar in the defensive response against the deleterious mechanisms caused by oxidative stress. An increasing body of evidence supports the concept that the pharmacological inhibition of the mPTP is an actual and promising strategy for the protection of tissues in ischemic situations in order to avoid the damage induced by perfusion.Fil: Stella, Carlos Alberto. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Burgos, Hilda Isabel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Chapela, Sebastián Pablo. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gamondi, Oliver. Universidad de Buenos Aires. Facultad de Medicina; Argentin

Involvement of L-carnitine in cellular metabolism: Beyond Acyl-CoA transport

Carnitine is well-known for its role in the transport of fatty acids to the mitochondrial matrix, where β-oxidation takes place. This work describes novel functions for this compound and novel data on its pharmacokinetics.Fil: Chapela, Sebastián Pablo. Universidad de Buenos Aires; ArgentinaFil: Kriguer, N.. Universidad de Buenos Aires; ArgentinaFil: Fernández, Ezequiel Hernán. Universidad de Buenos Aires; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

The Research Strategy Needs to Dialogue with the Science Student

The objective of the present work is to emphasize that although it is not possible to indicate a unique approach for the development of an investigation yet it is necessary for the student to analyze the chosen steps of a working plan. When students of both Biology and Medicine arrive at our laboratory to start a scientific research, away are in their minds the courses of introduction to scientific knowledge of the initial stages of their career. We analyze in the bibliography schemes and works that help the student and the responsible researcher to integrate student previous knowledge with literature focused on educational challenges and creative or critical thinking.The present work provides the basis for a dialogue between those in charge of research groups and students who are starting their labor in scientific education and research.The objective of the present work is to emphasize that although it is not possible to indicate a unique approach for the development of an investigation yet it is necessary for the student to analyze the chosen steps of a working plan. When students of both Biology and Medicine arrive at our laboratory to start a scientific research, away are in their minds the courses of introduction to scientific knowledge of the initial stages of their career. We analyze in the bibliography schemes and works that help the student and the responsible researcher to integrate student previous knowledge with literature focused on educational challenges and creative or critical thinking. The present work provides the basis for a dialogue between those in charge of research groups and students who are starting their labor in scientific education and research.Fil: Congost, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Chapela, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina. Hospital Británico de Buenos Aires; ArgentinaFil: Alonso, Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Burgos, Hilda Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Stella, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Observación del efecto reductor de N-Acetilcisteína en el metabolismo de levaduras

The research focuses on the design of experimental teaching using readily available materials and simple methods to implement. It arises as an example for learning, using baker's yeast Saccharomyces cerevisiae, because it has many of the metabolic pathways existing in mammalian cells. In this paper it was developed an essay that allow students to observe macroscopically the capacity of N- Acetyl cysteine (NAC) to stimulate the reducing power of yeast using indicator Methylene Blue (MB) color change.La investigación se centra en el diseño de didácticas experimentales utilizando materiales de fácil adquisición y métodos sencillos de poner en práctica. Se plantea como modelo de estudio el uso de la levadura de panadería Saccharomyces cerevisiae, ya que presenta muchas de las vías metabólicas estudiadas en células superiores. En este trabajo se propuso desarrollar un ensayo que permita observar macroscópicamente la capacidad de la N-Acetilcisteína (NAC) de estimular el poder reductor de la levadura utilizando el cambio de coloración del indicador Azul de Metileno (AM)