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We surveyed a subsurface layer of saturated mobile mud and its microbial fingerprints below the desiccated bottom of a maar lake at Rincón de Parangueo (RP), Mexico. A multi-scale approach was followed using geological fieldwork, coring of the sediments, ground penetrating radar survey, physico-chemical characterization including X-ray diffraction and scanning electron microscope, and high-throughput DNA sequencing methods. The mobile mud is an organic-rich silty clay, with high values of alkalinity, volumetric water content and conductivity. Mud mobility has been attributed to overpressure caused by disequilibrium compaction of sediments related to active subsidence and pore overpressure produced by an input of groundwater and gas content in the sediments and resulted in a diverse set of structures related to mud tectonics such as injection domes and fluid seeps through fractures. Extraction and sequencing of sedimentary environmental DNA in the mud layer were performed for Bacteria and Archaea. Despite the small number of samples obtained, the microbial fingerprint from the sedimentary environmental DNA at subsurface shares similarities with the microbial communities identified on the crater surface. Additionally, we identify the DNA of specific methanogenic microorganisms in the mud, such as Bathyarchaeia, Methanomassiliicoccales, and Methanobacteriales, and we speculate on their probable role in gas production and pore overpressure in the mud layer. The underground mud at Rincón de Parangueo represents a geologically dynamic environment with conditions that are favorable for the thriving of microbial communities.

Various types of stress initially induce a state of cardiac hypertrophy (CH) in the heart. But, persistent escalation of cardiac stress leads to progression from an adaptive physiological to a maladaptive pathological state. So, elucidating molecular mechanisms that can attenuate CH is imperative in developing cardiac therapies. Previously, we showed that Prohibitin1 (PHB1) has a protective role in CH-induced oxidative stress. Nevertheless, it is unclear how PHB1, a mitochondrial protein, has a protective role in CH. Therefore, we hypothesized that PHB1 maintains mitochondrial quality in CH. To test this hypothesis, we used Isoproterenol (ISO) to induce CH in H9C2 cells overexpressing PHB1 and elucidated mitochondrial quality control pathways.We found that overexpressing PHB1 attenuates ISO-induced CH and restores mitochondrial morphology in H9C2 cells. In addition, PHB1 blocks the pro-hypertrophic IGF1R/AKT pathway and restores the mitochondrial membrane polarization in ISO-treated cells. We observed that overexpressing PHB1 promotes mitochondrial biogenesis, improves mitochondrial respiratory capacity, and triggers mitophagy.We conclude that PHB1 maintains mitochondrial quality in ISO-induced CH in H9C2 cells.

Metagenomic and traditional paleolimnological approaches are suitable to infer past biological and environmental changes, however, they are often applied independently, especially in tropical regions. We combined both approaches to investigate Holocene Prokaryote and Eukaryote diversity and microbial metabolic pathways in ancient Lake Chalco, Mexico. Here, we report on diversity among a large number of lineages (36,722 OTUs) and functional diversity (27,636,243 non-clustered predicted proteins, and 6,144 annotated protein-family genes). The most abundant domain is Bacteria (81%), followed by Archaea (15%) and Eukarya (3%). We also determined the diversity of protein families and their relationship to metabolic pathways. The early Holocene (> 11,000 cal years BP) lake was characterized by cool, freshwater conditions, which later became warmer and hyposaline (11,000–6,000 cal years BP). We found high abundances of cyanobacteria, and fungi groups associated with mature forests in these sediments. Bacteria and Archaea include mainly anaerobes and extremophiles that are involved in the sulfur, nitrogen, and carbon cycles. We found evidence for early human impacts, including landscape modifications and lake eutrophication, which began ~ 6,000 cal years BP. Subsaline, temperate conditions were inferred for the past 5,000 years. Finally, we found nitrogen-fixing bacteria and protein-family genes that are linked to contaminated environments, as well as several fungal pathogens of crops in near-surface sediments.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, is a betacoronavirus endowed with one of the largest known RNA viral genomes. Two-thirds of its approximately 30,000 nts encode components of the replication–transcription complex, also known as replisome. This complex includes eight nonstructural proteins (nsps 7–10, 12–14, and 16). Nsp12 is a monomeric RNA-dependent RNA polymerase (RdRp) homologous to the RdRps found in all known RNA viruses, making it one of the most attractive therapeutic targets. Although SARS-CoV-2 and the hepatitis C virus (HCV) are not phylogenetically close, the structural similarities of the HCV NS3/4A with the coronaviral Mpro proteases support the possibility that the HCV protease inhibitors may also be used against SARS-CoV-2. The design of treatment guidelines against SARS-CoV-2, consisting of a combination of repurposed drugs against different viral targets, must be developed. Together with the RdRp and Mpro, another important therapeutic target would be the nsp14. This 527-amino acid exonuclease has a proofreading activity that attenuates the virus mutation rates by increasing replication fidelity. As mentioned here, the ExoN domain has played a key role in coronaviral evolution and appears to have been hijacked from a host cell.

Low complexity regions (LCRs) are protein sequences formed by a set of compositionally biased residues. LCRs are extremely abundant in cellular proteins and have also been reported in viruses, where they may partake in evasion of the host immune system. Here we report four novel extremely conserved LCRs in the spike proteins of several SARS-CoV-2 variants. With the exception of Iota, where it is absent, the Spike LCR-1 is present in the signal peptide of 80.57% of the Delta variant, and in other variants of concern and interest. The Spike LCR-2 is highly prevalent (79.87%) in Iota. Two distinctive LCRs are present in the Delta spike protein. The Delta Spike LCR-3 is present in 99.19% of the analyzed sequences, and the Delta Spike LCR-4 in 98.3% of the same set of proteins. These two LCRs are present in the furin cleavage site and HR1 domain, respectively, and may be considered hallmark traits of the Delta variant. The presence of two medically-important point mutations, P681R and D950N, in these LCRs, combined with the extraordinary conservation of these regions, suggests that they may be a trait associated with the rapid spread of the highly contagious Delta lineage.

Low complexity regions (LCRs) are protein sequences formed by a set of compositionally biased residues. LCRs are extremely abundant in cellular proteins and have also been reported in viruses, where they may partake in evasion of the host immune system. Analyses of 28,231 SARS-CoV-2 whole proteomes and of 261,051 spike protein sequences revealed the presence of four extremely conserved LCRs in the spike protein of several SARS-CoV-2 variants. With the exception of Iota, where it is absent, the Spike LCR-1 is present in the signal peptide of 80.57% of the Delta variant sequences, and in other variants of concern and interest. The Spike LCR-2 is highly prevalent (79.87%) in Iota. Two distinctive LCRs are present in the Delta spike protein. The Delta Spike LCR-3 is present in 99.19% of the analyzed sequences, and the Delta Spike LCR-4 in 98.3% of the same set of proteins. These two LCRs are located in the furin cleavage site and HR1 domain, respectively, and may be considered hallmark traits of the Delta variant. The presence of the medically-important point mutations P681R and D950N in these LCRs, combined with the ubiquity of these regions in the highly contagious Delta variant opens the possibility that they may play a role in its rapid spread.

For decades, paleoecological studies in lake sediments have focused on reconstructing the environments of the past and explaining phenomena linked to climatic variations. Recent advances in high-throughput DNA sequencing have allowed access to environmental DNA (eDNA) and ancient sedimentary DNA (sedaDNA) as a new and efficient proxy for past and present biodiversity. The basin of Mexico (BM) is located in the central part of the Trans-Mexican Volcanic Belt at 2,200 m a.s.l.; with the southern portion harboring the Chalco sub-basin. Lake Chalco is one of the last remaining natural aquatic ecosystems within the ever-expanding urban area surrounding Mexico City. The paleoenvironmental history of this lake has been previously characterized using sedimentological and geochemical proxies, as well as preserved microfossils (diatoms, pollen) with a temporal framework based on multiple radiocarbon dates. However, information for the remaining taxonomic groups and metabolic pathways remained unexplored. Here, we present the first metagenomics-based study for the Holocene in a high-altitude lake in Central Mexico –Lake Chalco. We explored the relationship between the lake’s paleoenvironmental condition and estimations of taxonomic and metabolic profiles across the sedimentary sequence (2.5 meters long). Multiple biological and abiotic variables revealed three main environmental phases: 1) a cool freshwater lake (FW1: 11,500-11,000 cal years BP), 2) a warm hyposaline lake (HS2: 11,000-6,000 cal years BP), and 3) a temperate, subsaline lake (SS3

In this manuscript we argue that the use of Sofosbuvir as a possible medication in the clinical treatment of COVID-19 can be complemented with HCV protease inhibitors given the homology between the HCV NS3/4A protease and the SARS-CoV-2 Mpro protease.

Of the six known autotrophic pathways, the Wood-Ljungdahl pathway (WL) is the only one present in both the acetate producing Bacteria (homoacetogens) and the methane producing Archaea (hydrogenotrophic methanogens), and it has been suggested that WL is one of the oldest metabolic pathways. However, only the so-called carbonyl branch is shared by Archaea and Bacteria, while the methyl branch is different, both in the number of reactions and enzymes, which are not homologous among them. In this work we show that some parts of the methyl branch of archaeal Wood-Ljungdahl pathway (MBWL) are present in bacteria as well as in non-methanogen archaea, although the tangled evolutionary history of MBWL cannot be traced back to the Last Common Ancestor. We have also analyzed the different variants of methanogenesis (hydrogenotrophic, acetoclastic and methylotrophic pathways), and concluded that each of these pathways, and every different enzyme or subunit (in the case of multimeric enzymes), has their own intricate evolutionary history. Our study supports the scenario of hydrogenotrophic methanogenesis being older than the other variants, albeit not old enough to be present in the last archaeal common ancestor., Financial support of DGAPA-UNAM (PAPIIT-IN223916) is gratefully acknowledged. IM-V is a student from the Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México (UNAM) and received fellowship 415961 from CONACyT. CGF and JP acknowledge financial support from Mineco/FEDER (grant references: BFU2015-64322-C2-1-R and BIO2015-66960-C3-1-R) and the Generalitat Valenciana (grant reference: PROMETEOII/2014/065).

Seminiferous tubules in mammals have histological arrangements defined by the associations between somatic cells and germ cells. The processes of DNA synthesis in meiotic and mitotic cells have different features that are not easily distinguishable through morphological means. In order to characterize the pre-meiotic S phase, 5-bromo-2’-deoxyuridine (BrdU) was injected intraperitoneally into Wistar rats, which were sacrificed 30 min, 2 hr, and 24 hr after injection. We found three different labeling patterns. One of these patterns was characterized by a distribution of the label in the form of speckles, most of which were associated with the nuclear envelope (labeling type I). We suggest that this pattern is due to mitotic DNA synthesis of type B spermatogonia. Labeling type II consisted of labeled foci scattered throughout the nuclear volume, which can be correlated with preleptotenic cells in pre-meiotic DNA synthesis. After 24 hr of incorporation, a third type of labeling, characterized by large speckles, was found to be related to cells in the “bouquet” stage; that is, cells in transition between the leptotene and zygotene phases. Our results indicate that BrdU incorporation induces different labeling patterns in the mitotic and pre-meiotic S phases and thus makes it possible to identify somatic and germinal cells.

ResumenLa cienciometría o bibliometría consiste en el análisis cuantitativo de la producción científica (en especial los artículos científicos), para investigar el desarrollo, estructura, dinámica, tendencias y relaciones de la práctica científica. Su desarrollo es uno de los efectos de la revolución digital en la ciencia, su uso en la medicina ha aumentado y las aplicaciones bibliométricas en el área médica pueden clasificarse en cinco categorías: recuperación de literatura, obtención de nuevo conocimiento, revisiones bibliográficas, análisis de las ciencias médicas, evaluación, gestión y política para medicina, se dan ejemplos de cada una. Los millones de datos médicos que se generan a partir de la literatura, los miles de colecciones bibliográficas que existen y los cientos de aplicaciones que hay en la actualidad para procesar y analizar la literatura, indican la importancia de preparar especialistas en México de alto nivel, capaces de dominar el procesamiento de literatura electrónica por métodos de innovadores y de vanguardia como la cienciometría. el primer paso para lograr este objetivo consistirá en enseñar a los médicos en formación las características, ventajas y perspectivas de este método.AbstractScientometrics or bibliometrics is the quantitative analysis of scientific production (especially papers) to investigate the development, structure, dynamics, trends and relationships of scientific practice. Their development is one of the effects of the digital revolution in science, their use in medicine has increased and the bibliometric applications in the medical field can be classified into five categories: recovery literature, obtaining new knowledge, literature reviews, medical science analysis, evaluation, management and medical policy, we give some examples. The millions of medical data that are generated from the literature, the thousands of library collections in the world and the hundreds of applications available today to process and analyze literature, indicate the importance of preparing medical specialists in Mexico that dominate the processing of electronic literature by innovative methods and cutting edge like scientometrics. The first step towards this goal will be to teach doctors in training features, advantages and perspectives of this method.

Yes Interface language English URL http://www.ncbi.nlm.nih.gov/pubmed Related document Yes Web 2.0 apps RSS, bookmarks, alerts, saved search results by e-mail. Document selection criteria Is based on the magazine Coverage: Articles mainly on basic biomedical research. Quality: validity, relevance, originality and contribution to the field coverage of content. Editorial quality, objectivity, credibility and quality of its contents, peer review, ethical quality, timely correction of errors. Production Quality: Design, printing, graphics and illustrations (but not pre-requisite) Audience: health professions: researchers, practitioners, educators, administrators and students. Content type: Reports of original research, original clinical observations accompanied by analysis and discussion, analysis of philosophical, ethical, social or health professions or biomedical sciences, critical commentaries, statistical compilations, descriptions of evaluation methods or procedures, case reports with discussions. Language: At least title and abstract in English. Geographic coverage: Generally not be selected for indexing if the contents are subjects already well represented in MEDLINE or published to a local audience. Records meta-analysis* No Tools My NCBI. Save searches, results, bibliography, and has an automatic update option. My NCBI preferences. Storage, highlight search terms, abstract screen, additional data. Furthermore, filtering of search results, view recent activity and the establishment of Link Out, document delivery service. Advantages Database more important, most used, most popular in biomedical information. Very short time to upgrade. It is complemented with other resources and information bases by the NCBI. Using multiple and varied fields of search. Disadvantages Few or no options for meta-analysis. Ambiguity in the identification of authors and documents. Table 3. Characteristics of PubMed database. *Meta-analysis details are explained below.