Introducing the concept of biocatalysis in the classroom: The conversion of cholesterol to provitamin D 3

Biocatalysis is a fundamental concept in biotechnology. The topic integrates knowledge of several disciplines; therefore, it was included in the course “design and optimization of biological systems” which is offered in the biochemistry curricula. We selected the ciliate tetrahymena as an example of a eukaryotic system with potential for the biotransformation of sterol metabolites of industrial interest; in particular, we focused on the conversion of cholesterol to provitamin D3. The students work with wild type and recombinant strains and learn how sterol pathways could be modified to obtain diverse sterol moieties. During the course the students identify and measure the concentration of sterols. They also search for related genes by bioinformatic analysis. Additionally, the students compare biotransformation rates, growing the ciliate in plate and in a bioreactor. Finally, they use fluorescence microscopy to localize an enzyme involved in biotransformation. The last day each team makes an oral presentation, explaining the results obtained and responds to a series of key questions posed by the teachers, which determine the final mark. In our experience, this course enables undergraduate students to become acquainted with the principles of biocatalysis as well as with standard and modern techniques, through a simple and robust laboratory exercise, using a biological system for the conversion of valuable pharmaceutical moieties.Fil: De Luca, Belén M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Nudel, Berta Clara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Gonzalez, Rodrigo Horacio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Nusblat, Alejandro David. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Hepatitis B Virus (HBV) and S-Escape Mutants: From the Beginning until Now

Despite of the progress made in vaccine and antiviral therapy development, hepatitis B virus (HBV) infection remains a major health care problem. More than 240 million people are chronically infected worldwide showing differences in the severity of liver disease, clinical outcome and response to immune- and antiviral-therapy. Parameters associated with the host immune system (HBV specific T- and/or B-cell repertoires, defective antigen presentation and diminished Th1/Th2 response ratio) and viral factors such as the HBV genotypes and their evolving variants/mutants, have largely contributed to explaining such differences. The unique genomic structure and replication cycle of HBV provide much opportunity for mutations to occur in any of its genes undergoing selection pressures, such as those associated with the host immune system, the hepatitis B vaccine and/or hepatitis B immune globulin and the antiviral therapy with nucleos(t)ide analogues. Firstly, this review describes the current prevalence of S-escape mutants worldwide. Secondly, the clinical implications of such surface gene variants and the impact of universal hepatitis B vaccination on HBV mutations and genotypes are discussed. Finally, the fact that the immune escape process also extends well beyond HBV is addressed.Fil: Perazzo, Priscila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Eguibar, Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Gonzalez, Rodrigo Horacio. Universidad de Buenos Aires; ArgentinaFil: Nusblat, Alejandro David. Universidad de Buenos Aires; ArgentinaFil: Cuestas, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Blue-light-dependent inhibition of twitching motility in Acinetobacter baylyi ADP1: additive involvement of three BLUF-domain-containing proteins

Twitching motility in Acinetobacter baylyi ADP1 is inhibited by moderate intensities of blue light in a temperature-dependent manner (maximally at 20 °C). We analysed the involvement of four predicted blue-light sensing using flavin (BLUF)-domain-containing proteins encoded in the genome of this strain in the twitching motility phenotype. All four genes were expressed both in light and in darkness. A phylogenetic tree showed that one BLUF domain, ACIAD2110, grouped separately from the other three (ACIAD1499, ACIAD2125 and ACIAD2129). Individual knockout mutants of the latter three, but not of ACIAD2110, fully abolished the light dependency of the twitching motility response. Quantitative analysis of transcript level of the three genes showed a decreased expression in the light, with dark/light ratios of 1.65±0.28, 1.79±0.21 and 2.69±0.39, for ACIAD2125, ACIAD2129 and ACIAD1499, respectively. Double and triple knockouts of ACIAD1499, ACIAD2125 and ACIAD2129 confirmed the same phenotype as the corresponding single knockouts. Complementation of all the single knockouts and the triple knockout mutants with any of the three BLUF-domain-encoding genes fully restored the inhibition of twitching motility by blue light that is observed in the wild-type strain. A. baylyi ADP1 therefore shows a high degree of redundancy in the genes that encode BLUF-containing photoreceptors. Moreover, all plasmid-complemented strains, expressing any of the BLUF proteins irrespective of the specific set of deleted photoreceptors, displayed increased light-dependent inhibition of twitching motility, as compared to the wild-type (P<0.001). We conclude that the three genes ACIAD1499, ACIAD2125 and ACIAD2129 are jointly required to inhibit twitching motility under moderate blue-light illumination.Fil: Bitrian, Mariana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Gonzalez, Rodrigo Horacio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Paris, Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; ArgentinaFil: Hellingwerf, Klaas. University Of Amsterdam; Países BajosFil: Nudel, Berta Clara. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Nanotechnology, Drug Delivery Systems and their Potential Applications in Hepatitis B Vaccines

Since the Nobel Prize in Physiology or Medicine 1976 Baruch Blumberg and Irving Millman developed the first prophylactic plasma-derived hepatitis B vaccine - also considered the world´s first cancer vaccine- so much progress has been made in the development of new immunogenic and safe vaccines. However, improvements are still clearly required since vaccines currently available in the market produce mainly a humoral immune response, require cold storage, a three dose schedule, the costs of the vaccines are high, many developing or low-incoming countries display a poor compliance in vaccination programs, and 5-10% of the vaccinated individuals are poor or non-responders.To overcome such drawbacks, nanotechnology has emerged as a new platform for vaccine development. Nanocarrier-based delivery systems offer an opportunity to stimulate both humoral as well as cell-mediated responses and to induce mucosal and systemic immunity simultaneously. Furthermore, nanocarrier-based delivery systems avoid the need for sterile needles. This manuscript reviews the current knowledges on the vailable hepatitis B vaccines and introduces the recent advances in nanocarrier-based hepatitis B vaccine delivery systems. The challenges in the development of needle-free nanotechnologies are also discussed.Fil: Perazzo, Priscila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Rodriguez del Valle, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Sordelli, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Gonzalez, Rodrigo Horacio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; ArgentinaFil: Nusblat, Alejandro David. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Microbiología Industrial y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cuestas, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Metastatic pheochromocytoma to liver without elevation of metanephrines and catecholamines

AbstractIntroductionMalignant pheochromocytoma represents 10% of all patients with pheochromocytoma. Of these cases, only 5–9% presents without elevation of metanephrines and catecholamines.Presentation of caseA 43-year-old female patient presented with an abdominal tumor. An exploratory laparotomy was performed and the final report was a pheochromocytoma. After ten years, multiple liver lesions were detected and surgical treatment was performed. Pathological evaluation revealed a malignant pheochromocytoma with negative margins after 5 years of follow-up without evidence of disease.DiscussionThe recurrence rate of malignant pheochromocytoma is 15–20% at ten years and a 5-year survival rate that ranges from 50% to 80%. The presence of synchronous metastases is rare (10–27%), but have been reported until 20 years later with the most common metastatic sites being the local lymph nodes, bone (50%), liver (50%) and lung (30%). The prognostic factor such as size >6cm, age over 45 years, synchronous metastasis and no tumor excision are related with poor prognosis.ConclusionSurgical treatment offers the best survival rate and the only chance of cure so far and the goal is an R0 resection as in our case. So it should be the treatment of choice

Calidad de fibra Mohair de esquila de otoño en establecimientos de la zona centro de la provincia de Neuquén

El objetivo de este trabajo fue describir la variabilidad fenotípica de la calidad de Mohair en establecimientos de la zona centro de Neuquén. Durante la esquila de otoño del año 2017, se realizaron muestreos en 10 establecimientos pertenecientes al proyecto de mejora de la productividad primaria ganadera, en el marco del Cluster Caprino. Las muestras de fibra recolectadas se tomaron de la zona media del costillar de los animales y contienen información individual declarada por los productores. Las muestras fueron analizadas en el Laboratorio de Fibras Textiles de Origen Animal (LFTOA) del INTA Bariloche, y las variables de calidad de fibra evaluadas fueron: Diámetro Medio de Fibras (DMF), coeficiente de variación del DMF (CVDMF), Factor de Confort (FC), Largo de Mecha (LM), Rendimiento al Lavado (RIN), Fibras Meduladas Continuas (FMC), Fibras Meduladas Discontinuas (FMD), Kemps y Fibras Meduladas Totales (FMT). A partir de los datos generados se realizaron análisis de varianza (ANOVA) y análisis multivariados de Componentes Principales. Los valores promedios de DMF para animales Angora y Cruza resultaron en 27,6 μm y 28,8 μm, respectivamente, no detectándose diferencias significativas entre ellos. Por otro lado, los grupos etarios Dl, 2d y 4d registraron valores superiores de DMF en los animales Cruza en comparación a los de Angora. A su vez, los valores de DMF y LM tuvieron una tendencia creciente con la edad de los animales. Los animales Cruza resultaron con un 5% de FMT, siendo estadísticamente superior al 3,2% de FMT de los animales Angora. El análisis de calidad de fibra basado en datos individuales de animales podría constituir una base preliminar para desarrollar un protocolo de seguimiento de la producción y la variabilidad de la calidad de Mohair a escala predial, que permita tomar decisiones productivas y monitorear la evolución de la calidad de la fibra a escala provincial.Estación Experimental Agropecuaria BarilocheFil: Gonzalez, Ezequiel Bernardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Producción Animal. Laboratorio de Fibras Textiles de Origen Animal; ArgentinaFil: Easdale, Marcos Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFIl: Sacchero, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Producción Animal. Laboratorio de Fibras Textiles de Origen Animal; ArgentinaFil: Giovannini, Nicolas. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Martinez, Abel Hector Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Zapala; ArgentinaFil: Trova, Santiago. Direccion Provincial Desarrollo Rural. Subsecretaria de Producción de Neuquén; ArgentinaFil: Navedo, Rodrigo Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Zapala; ArgentinaFil: Taborda, María Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Zapala; ArgentinaFil: Zúñiga, Fabián. Programa Mohair Neuquen; Argentin

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Impact of common cardio-metabolic risk factors on fatal and non-fatal cardiovascular disease in Latin America and the Caribbean: an individual-level pooled analysis of 31 cohort studies

Background: Estimates of the burden of cardio-metabolic risk factors in Latin America and the Caribbean (LAC) rely on relative risks (RRs) from non-LAC countries. Whether these RRs apply to LAC remains un- known. Methods: We pooled LAC cohorts. We estimated RRs per unit of exposure to body mass index (BMI), systolic blood pressure (SBP), fasting plasma glucose (FPG), total cholesterol (TC) and non-HDL cholesterol on fatal (31 cohorts, n = 168,287) and non-fatal (13 cohorts, n = 27,554) cardiovascular diseases, adjusting for regression dilution bias. We used these RRs and national data on mean risk factor levels to estimate the number of cardiovascular deaths attributable to non-optimal levels of each risk factor. Results: Our RRs for SBP, FPG and TC were like those observed in cohorts conducted in high-income countries; however, for BMI, our RRs were consistently smaller in people below 75 years of age. Across risk factors, we observed smaller RRs among older ages. Non-optimal SBP was responsible for the largest number of attributable cardiovascular deaths ranging from 38 per 10 0,0 0 0 women and 54 men in Peru, to 261 (Dominica, women) and 282 (Guyana, men). For non-HDL cholesterol, the lowest attributable rate was for women in Peru (21) and men in Guatemala (25), and the largest in men (158) and women (142) from Guyana. Interpretation: RRs for BMI from studies conducted in high-income countries may overestimate disease burden metrics in LAC; conversely, RRs for SBP, FPG and TC from LAC cohorts are similar to those esti- mated from cohorts in high-income countries

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)