Microalgae-Based Biotechnology as Alternative Biofertilizers for Soil Enhancement and Carbon Footprint Reduction: Advantages and Implications.

Due to the constant growth of the human population and anthropological activity, it has become necessary to use sustainable and affordable technologies that satisfy the current and future demand for agricultural products. Since the nutrients available to plants in the soil are limited and the need to increase the yields of the crops is desirable, the use of chemical (inorganic or NPK) fertilizers has been widespread over the last decades, causing a nutrient shortage due to their misuse and exploitation, and because of the uncontrolled use of these products, there has been a latent environmental and health problem globally. For this reason, green biotechnology based on the use of microalgae biomass is proposed as a sustainable alternative for development and use as soil improvers for crop cultivation and phytoremediation. This review explores the long-term risks of using chemical fertilizers for both human health (cancer and hypoxia) and the environment (eutrophication and erosion), as well as the potential of microalgae biomass to substitute current fertilizer using different treatments on the biomass and their application methods for the implementation on the soil; additionally, the biomass can be a source of carbon mitigation and wastewater treatment in agro-industrial processes.

The Novel Phosphatase Domain Mutations Q171R and Y65S Switch PTEN from Tumor Suppressor to Oncogene.

Phosphatase and tensin homolog deleted on chromosome 10, or PTEN, is a well-characterized tumor suppressor with both lipid and protein phosphatase activities. PTEN is often downregulated by epigenetic mechanisms such as hypermethylation, which leads to constitutive activation of the PI3K-Akt pathway. Large datasets from next-generation sequencing, however, revealed that mutations in PTEN may not only hamper protein function but may also affect interactions with downstream effectors, leading to variable oncogenic readouts. Here, two novel PTEN mutations, Q171R and Y65S, identified in Filipino colorectal cancer patients, were phenotypically characterized in NIH3T3 and HCT116 cells, alongside the C124S canonical mutant and wild-type controls. The novel mutants increased cellular proliferation, resistance to apoptosis and migratory capacity. They induced gross morphological changes including cytoplasmic shrinkage, increased cellular protrusions and extensive cytoskeletal reorganization. The mutants also induced a modest increase in Akt phosphorylation. Further mechanistic studies will help determine the differential oncogenic potencies of these mutants, and resolve whether the structural constraints imposed by the mutations may have altered associations with downstream effectors.

Importancia de compuestos antimicrobianos producidos por bacterias benéficas en el biocontrol de fitopatógenos / The importance of antimicrobial compounds produced by beneficial bacteria on the biocontrol of phytopathogens

ABSTRACT Bacteria produce antimicrobial compounds to compete for nutrients and space in a particular habitat. Antagonistic interactions can be evaluated by several methodologies including the double-layer agar and simultaneous inhibition assays. Among the well-known inhibitory substances produced by bacteria are the broad-spectrum antibiotics, organic acids, siderophores, antifungal, and bacteriocins. The most studied bacterial genera able to produce these inhibitory substances are Enterococcus, Lactococcus, Streptomyces, Bacillus, Pseudomonas, Klebsiella, Escherichia, and Burkholderia. Some beneficial bacteria can promote plant growth and degrade toxic compounds in the environment representing an attractive solution to diverse issues in agriculture and soil pollution, particularly in fields with damaged soils where pesticides and fertilizers have been indiscriminately used. Beneficial bacteria may increase plant health by inhibiting pathogenic microorganisms; some examples include Gluconacetobacter diazotrophicus, Azospirullum brasilense, Pseudomonas fluorescens, Pseudomonas protegens, and Burkholderia tropica. However, most studies showing the antagonistic potential of these bacteria have been performed in vitro, and just a few of them have been evaluated in association with plants. Several inhibitory substances involved in pathogen antagonism have not been elucidated yet; in fact, we know only 1 % of the bacterial diversity in a natural environment leading us to assume that many other inhibitory substances remain unexplored. In this review, we will describe the characteristics of some antimicrobial compounds produced by beneficial bacteria, the principal methodologies performed to evaluate their production, modes of action, and their importance for biotechnological purposes.

RESUMEN Las bacterias producen compuestos antimicrobianos para competir por nutrientes y espacio en un hábitat particular. Las interacciones antagónicas pueden evaluarse mediante varias metodologías, incluido el agar de doble capa y los ensayos de inhibición simultánea. Las sustancias inhibidoras mejor conocidas producidas por bacterias incluyen antibióticos, ácidos orgánicos, sideróforos, antifúngicos y bacteriocinas. Entre los géneros bacterianos más estudiados que producen sustancias inhibidoras se incluyen Enterococcus, Lactococcus, Streptomyces, Bacillus, Pseudomonas, Klebsiella, Escherichia y Burkholderia. Algunas bacterias beneficiosas tienen la capacidad de promover el crecimiento de las plantas y degradar compuestos tóxicos en el ambiente, por lo que podrían incrementar el rendimiento de los cultivos y disminuir problemas de contaminación del suelo, especialmente donde los pesticidas y fertilizantes han sido utilizados indiscriminadamente. Algunas bacterias beneficiosas pueden aumentar la salud de las plantas al inhibir microorganismos patógenos, por ejemplo, Gluconacetobacter diazotrophicus, Azospirullum brasilense, Pseudomonas fluorescens, Pseudomonas protegens y Burkholderia tropica. Sin embargo, la mayoría de los estudios que muestran el potencial antagónico de estas bacterias se han realizado in vitro, y pocos de ellos se han evaluado en asociación con plantas. Varias sustancias inhibitorias implicadas en el antagonismo de los patógenos aún son desconocidas; de hecho, sabemos que solo se ha aislado el 1 % de la diversidad bacteriana en un ambiente natural, lo que sugiere que hay muchas otras sustancias inhibitorias que no han sido exploradas. En esta revisión describimos las características de algunos compuestos antimicrobianos producidos por bacterias beneficiosas, las principales metodologías usadas para evaluar su producción, modos de acción y su importancia para fines biotecnológicos.

Non-Redundant and Overlapping Oncogenic Readouts of Non-Canonical and Novel Colorectal Cancer KRAS and NRAS Mutants.

RAS oncogene family members are molecular switches of signaling pathways that control cell growth, proliferation, differentiation, and survival. In colorectal cancer, Kirsten-RAS (KRAS) and neuroblastoma-RAS (NRAS) are the commonly mutated isoforms. Activating mutations in RAS result in cellular transformation independent of upregulated epidermal growth factor receptor (EGFR)-initiated signaling. The present study characterized the functional consequences of non-canonical/novel KRAS and NRAS mutants identified in a targeted next-generation sequencing study of colorectal cancer specimens from Filipino patients. In vitro assays in NIH3T3 cells showed that similar to the canonical KRAS G12D mutant, overexpression of KRAS G12S, A59T, and Y137C, but not NRAS G12D and NRAS A11V, confer higher proliferation and migration rates. HCT116 cells transfected with the novel NRAS A11V and the canonical NRAS G12D, but not the KRAS mutants, display enhanced resistance to apoptosis. All four non-canonical/novel KRAS and NRAS mutants induce gross changes in F-actin cytoskeletal organization and cellular morphology of NIH3T3 cells. Only KRAS G12S and KRAS A59T appear to deregulate extracellular signal-regulated kinase (ERK) and its downstream target ETS transcription factor ELK1 (ELK1). Elucidation of differential effector engagement responsible for the variable phenotypic readouts of the mutants is warranted. If validated by mouse studies and clinical correlates, these can have wider implications in choosing treatment options.

Calcium handling precedes cardiac differentiation to initiate the first heartbeat.

The mammalian heartbeat is thought to begin just prior to the linear heart tube stage of development. How the initial contractions are established and the downstream consequences of the earliest contractile function on cardiac differentiation and morphogenesis have not been described. Using high-resolution live imaging of mouse embryos, we observed randomly distributed spontaneous asynchronous Ca2+-oscillations (SACOs) in the forming cardiac crescent (stage E7.75) prior to overt beating. Nascent contraction initiated at around E8.0 and was associated with sarcomeric assembly and rapid Ca2+ transients, underpinned by sequential expression of the Na+-Ca2+ exchanger (NCX1) and L-type Ca2+ channel (LTCC). Pharmacological inhibition of NCX1 and LTCC revealed rapid development of Ca2+ handling in the early heart and an essential early role for NCX1 in establishing SACOs through to the initiation of beating. NCX1 blockade impacted on CaMKII signalling to down-regulate cardiac gene expression, leading to impaired differentiation and failed crescent maturation.

Study of the activity of several brain enzymes like markers of the neurotoxicity induced by perinatal exposure to lead and/or cadmium.

Five enzymes, considered keys to the correct function of the central nervous system (CNS) were chosen to study their utility as markers of the possible neurotoxic effects produced by the perinatal exposure to lead and/or cadmium. With this aim, lead acetate (300 mg/l) and/or cadmium acetate (10 mg/l) were administered to pregnant Wistar rats from day 1 of pregnancy to parturition (day 0) or until weaning (day 21). Brains were used to determine the activity of acid phosphatase (ACP), alkaline phosphatase (ALP), catalase (CAT), acetylcholinesterase (AchE) and ATP-ases (Na(+)/K(+) and Mg(2+)/Ca(2+) dependent). The general decrease of the activity of these enzymes observed after the treatment with heavy metals suggests that lead and cadmium are able to reach the CNS and impair its function by neurochemical changes. On the other hand, the results showed an increase of the activity of CAT; which possibly indicates that lead and cadmium might have other mechanisms of action, such as increasing oxidative damage in the CNS. Finally, the study of the effects produced by the simultaneous administration of lead and cadmium suggests that, in general, both metals exert an additive effect, either competing for the same inhibitory binding sites or increasing cellular damage. In conclusion, the study of the activity of enzymes is revealed as an effective method to measure the neurotoxicity induced by lead and cadmium.

Radicalidad en cancer gastrico: orientación pronóstica / Radical gastric cancer: pronostic orientation

Con el objeto de determinar el valor de la ricalidad en la estadiación final del paciente con cáncer gástrico, se revisaron 18 casos tratados quirúrgicamente, a través de un protocolo quirúrgico- histopatológico, basado en las reglas de la sociedad japonesa de investigación de cáncer gástrico, entre agosto 1994 y abril 1998, en el Hospital "Dr. Luis Gómez López", del MSAS, de Barquisimeto. El porcentaje de disección de los grupos ganglionares fue: #1:88,9 por ciento; #2:33,3 por ciento; #3:100 por ciento; #4D:94,4 por ciento; #4S:33,3 por ciento; #5:44,4 por ciento; #6:100 por ciento #7:88,9 por ciento; #8:88,9 por ciento; #9:77,8 por ciento; #10: 38,9 por ciento; #11:61,1 por ciento; #12:77,8 por ciento; #13:5,6 por ciento; #14:16,7 por ciento; #15: 27,8 por ciento; #16:61,1 por ciento; #17:11,1 por ciento, según la radicalidad realizada DO+&: 1;D1+&: 1; D2+&:13; D4: en 3 casos, respectivamente, siendo los #12 y #16 los más frecuentes disecados en forma aislada. El n final fue : n0: 5 (27,7 por ciento); n1: 4 (22,2 por ciento); n2: 3 (16,7 por ciento); n3: 2 (11,1 por ciento); n4: 4 (22,2 por ciento.Al relacionarse el N preoperatorio tomográfico, con el n quirúrgico histopatológico, se encontró para la TAC una sensibilidad (S) del 5o por ciento en la detección de nódulos linfáticos de diámetro >- a 1,5 cm, para los grupos #45S y #17, respectivamente, con una especificidad (E) para dichos grupos del 100 por ciento; además de una S:0 por ceinto para nódulos linfáticos en los grupos #1,3 4D, 5,6, 7,8 ,9 ,10. 11, 12, 15, y 16, respectivamente, sobrevalorándose el N en el #10 y 316 , con una E: 83,3 por ciento y 75 por ciento siendo la E para el resto de los grupos ganglianares del 100 por ciento. Se concluye, que sólo a través de la radicalidad, como parte del tratamiento del paciente con cáncer gástrico, y al examen histopatológico apropiado, y por separado de cada grupo ganglionar disecado, se llega al estadio correcto del n, lo cual es imprescindible para la correcta valoración del pronóstico en cada caso

Apuntes de geologia

Contenido: Nociones generales, seres naturales, geologia, breve noticia historica, importancia de la geologia, division.