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Arid and semi-arid areas are highly productive ecosystems that have a great diversity of species, among which grasses stand out. These species have ecological, environmental, and economic importance. The objective was to identify the ecological descriptors of 15 native species of grasses and diversity patterns through multivariate analysis techniques (principal component analysis, PCA, and cluster analysis, CA), in addition to identifying potential distribution areas (current and future) and regions of high and low diversity from 3841 accessions and 21 climatic variables. Among the main results, the extreme values, coefficient of variation, and median for each species could be determined. PCA determined that, with 10 variables, it was possible to explain 54.36% of the variation between the analyzed species. CA resulted in the formation of four statistically significant groups, with specific climatic characteristics. Regarding potential distribution areas and climate change, a reduction in distribution is expected (2050) on most of the current surface, with a possible opportunity zone in the north of the country. Finally, two hotspots (high diversity areas) and four coldspots (low diversity areas) were identified among the analyzed species. These results can be used to create strategies for sustainable use and the conservation of these resources.

Background: Azo pigments are widely used in the textile and leather industry, and they generate diverse contaminants (mainly in wastewater effluents) that affect biological systems, the rhizosphere community, and the natural activities of certain species. Methods: This review was performed according to the Systematic Reviews and Meta Analyses (PRISMA) methodology. Results: In the last decade, the use of Streptomyces species as biological azo-degraders has increased, and these bacteria are mainly isolated from mangroves, dye-contaminated soil, and marine sediments. Azo pigments such as acid orange, indigo carmine, Congo red, and Evans blue are the most studied compounds for degradation, and Streptomyces produces extracellular enzymes such as peroxidase, laccase, and azo reductase. These enzymes cleave the molecule through asymmetric cleavage, followed by oxidative cleavage, desulfonation, deamination, and demethylation. Typically, some lignin-derived and phenolic compounds are used as mediators to improve enzyme activity. The degradation process generates diverse compounds, the majority of which are toxic to human cells and, in some cases, can improve the germination process in some horticulture plants. Conclusions: Future research should include analytical methods to detect all of the molecules that are generated in degradation processes to determine the involved reactions. Moreover, future studies should delve into consortium studies to improve degradation efficiency and observe the relationship between microorganisms to generate scale-up biotechnological applications in the wastewater treatment industry.

Chronic hepatitis B virus (HBV) infection remains a global health problem due to the lack of treatments that prevent viral rebound from HBV covalently closed circular (ccc)DNA. In addition, HBV DNA integrates in the human genome, serving as a source of hepatitis B surface antigen (HBsAg) expression, which impairs anti-HBV immune responses. Cytosine base editors (CBEs) enable precise conversion of a cytosine into a thymine within DNA. In this study, CBEs were used to introduce stop codons in HBV genes, HBs and Precore. Transfection with mRNA encoding a CBE and a combination of two guide RNAs led to robust cccDNA editing and sustained reduction of the viral markers in HBV-infected HepG2-NTCP cells and primary human hepatocytes. Furthermore, base editing efficiently reduced HBsAg expression from HBV sequences integrated within the genome of the PLC/PRF/5 and HepG2.2.15 cell lines. Finally, in the HBV minicircle mouse model, using lipid nanoparticulate delivery, we demonstrated antiviral efficacy of the base editing approach with a >3log10 reduction in serum HBV DNA and >2log10 reduction in HBsAg, and 4/5 mice showing HBsAg loss. Combined, these data indicate that base editing can introduce mutations in both cccDNA and integrated HBV DNA, abrogating HBV replication and silencing viral protein expression.

Introducción. El tacrolimus es un medicamento inmunosupresor ampliamente usado en trasplante hepático, que presenta una gran variabilidad interindividual la cual se considera asociada a la frecuencia de polimorfismos de CYP3A5 y MDR-1. El objetivo de este estudio fue evaluar la frecuencia de los polimorfismos rs776746, rs2032582 y rs1045642 y su asociación con rechazo clínico y toxicidad farmacológica. Métodos. Se incluyeron pacientes inmunosuprimidos con tacrolimus a quienes se les realizó trasplante hepático en el Hospital San Vicente Fundación Rionegro entre 2020 y 2022, con supervivencia mayor a un mes. Se evaluaron las variables clínicas, rechazo agudo y toxicidad farmacológica. Se secuenciaron los genes de estudio mediante PCR, comparando la expresión o no en cada uno de los pacientes. Resultados. Se identificaron 17 pacientes. El 43 % de los pacientes se clasificaron como CYP3A5*1/*1 y CYP3A5*1/*3, entre los cuales se encontró asociación con aumento en la tasa de rechazo agudo clínico, al comparar con los pacientes no expresivos (100 % vs. 44 %, p=0,05); no hubo diferencias en cuanto a la toxicidad farmacológica u otros desenlaces. Se encontró el polimorfismo rs2032582 en un 50 % y el rs1045642 en un 23,5 % de los pacientes, sin embargo, no se identificó asociación con rechazo u otros eventos clínicos. Conclusiones. Se encontró una asociación entre el genotipo CYP3A5*1/*1 y CYP3A5*1/*3 y la tasa de rechazo clínico. Sin embargo, se requiere una muestra más amplia para validar estos datos y plantear modelos de medicina personalizada.