Congo red induces trans-priming to UV-B radiation in Metarhizium robertsii.

Metarhizium spp. is used as a biocontrol agent but is limited because of low tolerance to abiotic stress. Metarhizium robertsii is an excellent study model of fungal pathogenesis in insects, and its tolerance to different stress conditions has been extensively investigated. Priming is the time-limited pre-exposure of an organism to specific stress conditions that increases adaptive response to subsequent exposures. Congo red is a water-soluble azo dye extensively used in stress assays in fungi. It induces morphological changes and weakens the cell wall at sublethal concentrations. Therefore, this chemical agent has been proposed as a stressor to induce priming against other stress conditions in entomopathogenic fungi. This study aimed to evaluate the capacity of Congo red to induce priming in M. robertsii. Conidia were grown on potato dextrose agar with or without Congo red.The tolerance of conidia produced from mycelia grown in these three conditions was evaluated against stress conditions, including osmotic, oxidative, heat, and UV-B radiation. Conidia produced on medium supplemented with Congo red were significantly more tolerant to UV-B radiation but not to the other stress conditions assayed. Our results suggest that Congo red confers trans-priming to UV-B radiation but not for heat, oxidative, or osmotic stress.

Tolerance to UV-B radiation of the entomopathogenic fungus Metarhizium rileyi.

Soybean, corn, and cotton crops are afflicted by several noctuid pests and the development of bioinsecticides could help control these pests. The fungus Metarhizium rileyi has the greatest potential because its epizootics decimate caterpillar populations in the absence of insecticide applications. However, insect-pathogenic fungi when used for insect control in agriculture have low survival mainly due to the deleterious effects of ultraviolet radiation and heat from solar radiation. In this study, fourteen isolates of M. rileyi were studied and compared with isolates ARSEF 324 and ARSEF 2575 of Metarhizium acridum and Metarhizium robertsii, respectively, whose sensitivity to UV-B radiation had previously been studied. Conidia were exposed at room temperature (ca. 26 °C) to 847.90 mWm-2 of Quaite-weighted UV-B using two fluorescent lamps. The plates containing the conidial suspensions were irradiated for 1, 2, and 3 h, providing doses of 3.05, 6.10, and 9.16 kJ m2, respectively. A wide variability in conidial UV-B tolerance was found among the fourteen isolates of M. rileyi. Isolate CNPSo-Mr 150 was the most tolerant isolate (germination above 80% after 2 h exposure), which was comparable to ARSEF 324 (germination above 90% after 2 h exposure), the most tolerant Metarhizium species. The least tolerant isolates were CNPSo-Mr 141, CNPSo-Mr 142, CNPSo-Mr 156, and CNPSo-Mr 597. Nine M. rileyi isolates exhibited similar tolerance to UV-B radiation as ARSEF 2575 (germination above 50% after 2 h exposure). In conclusion, the majority of M. rileyi isolates studied can endure 1 or 2 h of UV-B radiation exposure. However, after 3 h of exposure, the germination of all studied isolates reduced below 40%, except for CNPSo-Mr 150 and ARSEF 324.

Efficacy of Antineoplastic Nanocarriers on 3D Oral Cancer Spheroids.

BACKGROUND/AIM: Cancer is a leading cause of death worldwide. Conventional treatments as surgery, chemotherapy, radiotherapy, and combined therapies are commonly used. However, these therapies have several limitations and side effects. To address these issues, innovative research is being conducted on nanocarriers (NCs) functionalized with antineoplastic agents. These NCs aim to overcome limitations and improve patients' lives. However, before they can be used clinically, these NCs are primarily assessed on a lab scale to determine their efficacy. MATERIALS AND METHODS: A primary cell culture was established from a lymphoblastic neoplasm in the maxilla. After characterization, the cells were cultured in 2D to evaluate the dose-effect of nanoparticles (NPs), such as Zinc oxide (ZnO) and Magnesium oxide (MgO), as well as those of free drugs of 5-fluorouracil (5-FU) and cisplatin (Cis). Based on the results, a 3D spheroid culture was used for further study. Finally, the spheroids were histologically processed for immuno-morphological observation. RESULTS: To evaluate spheroid cell viability, we conducted an MTT assay. Treatment of cell spheroids with ZnONPs, 5-FU, and NPs conjugated with antitumor agents such as 5-FU-ZnO and Cis-ZnO decreased cell viability by >25%, >60% and >10% and <20% at a concentration of 0.06, 0.015 and 0.015 & 0.03 mg/ml, respectively. CONCLUSION: Nanoparticles conjugated with antitumor agents showed promising antineoplastic effects on both 2D and 3D cell cultures. However, the efficacy of the nanoparticles varied between the different models. This highlights the importance of selecting appropriate in vitro culture models for the evaluation of biomedical agents.

[Dysnatremias and their association with morbidity and mortality in patients with COVID- 19]. / Disnatremias y su asociación con morbimortalidad en pacientes con COVID-19.

Background: Coronavirus disease 2019 (COVID-19) has provoked one of the greatest health crises of our time, which is why risk stratification at the time of hospitalization is essential to identify in good time patients with high morbidity and mortality risk. Dysnatremia as an independent predictor of mortality in patients with COVID-19 has recently become relevant. Objective: To find out if there is an association of dysnatremia with 28-day mortality, and as secondary objectives, its association with hospital stay, invasive mechanical ventilation (IMV) requirement and presence of acute kidney injury (AKI) during hospital stay. Material and methods: Retrospective, descriptive and analytical cohort study. All consecutive patients of 16 years or older of any gender, admitted to a third level hospital from March 1, 2020 to March 2021, who have a diagnosis of COVID-19 with positive PCR were included. Results: The study included a total of 722 patients. The prevalence of dysnatremia was as follows: 18 patients presented hypernatremia (2.49%) and 153 hyponatremia (21.19%). The presence of hypernatremia once sodium was corrected for glucose was associated with higher mortality (p < 0.05, OR 3.446; 95% CI 1.776-6.688), an increased probability of presenting AKI (p <0.05, OR 2.985; 95% CI 1.718-5.184) and a greater requirement for IMV (p < 0.05, OR 1.945; 95% CI 1.701-5.098). Conclusions: Hypernatremia was associated with higher mortality, higher risk of presenting AKI and the requirement for IMV during hospitalization.

Introducción: la enfermedad por coronavirus 2019 (COVID-19) ha provocado una de las mayores crisis sanitarias de nuestros tiempos, por lo que la estratificación pronóstica al momento de la hospitalización es fundamental para identificar de manera temprana a los pacientes con alto riesgo de morbimortalidad. La disnatremia como predictor independiente de mortalidad en pacientes con COVID-19 ha tomado relevancia recientemente. Objetivo: encontrar si existe asociación de disnatremias con mortalidad a 28 días y como secundarios su asociación con estancia hospitalaria, requerimiento de ventilación mecánica invasiva (VMI) y presencia de lesión renal aguda (LRA) durante la estancia hospitalaria. Material y métodos: estudio de tipo cohorte retrospectivo, descriptivo y analítico. Se incluyeron de manera consecutiva todos los pacientes mayores de 16 años de cualquier género, ingresados en un hospital de tercer nivel de marzo de 2020 a marzo de 2021, los cuales presentaron diagnóstico de COVID-19 con PCR positiva. Resultados: el estudio incluyó un total de 722 pacientes. La prevalencia de disnatremia fue la siguiente: 18 pacientes presentaron hipernatremia (2.49%) y 153 hiponatremia (21.19%). La presencia de hipernatremia una vez corregido el sodio para la glucosa se asoció con mayor mortalidad (p < 0.05, RM 3.446; IC 95%, 1.776-6.688), un aumento de la probabilidad de presentar LRA (p < 0.05, RM 2.985; IC 95%, 1.718-5.184) y mayor requerimiento de VMI (p < 0.05, RM 1.945; IC 95%, 1.701-5.098). Conclusiones: la hipernatremia se asoció a una mayor mortalidad, mayor riesgo de presentar LRA y requerimiento de VMI durante la hospitalización.

The Nervous System as a Regulator of Cancer Hallmarks: Insights into Therapeutic Implications.

The involvement of the nervous system in the development of cancer is controversial. Several authors have shown opinions and conflicting evidence that support the early effect of the nervous system on the carcinogenic process. For about a century, research has not been enough, questions remain open, ideas are not discarded, and although more research is still needed to answer all the questions, there is now enough evidence to support the theories and give hope of finding one more possible form of treatment. It is clear that malignant neoplasms have endogenous characteristics that allow them to establish and progress. Some of these characteristics known as hallmarks of cancer, are damage mechanisms in the pathology but necessary during other physiological processes which show some nerve dependence. The nervous system communicates with the whole organism, regulating physiological processes necessary to respond to external stimuli and for the maintenance of homeostasis. The modification of nerve activity could generate an overload and deregulate the state of cellular and tissue homeostasis; this could drive cancer development. In this review, we will address the issue in an evidence-oriented manner that supports that the nervous system is able to participate in the initial and progressive process of carcinogenesis by inducing biochemical, physiological, and cellular modifications involved in the hallmarks of cancer.

[Sodium-chlorine difference as a prognostic predictor in adult patients diagnosed with COVID-19]. / Diferencia sodio-cloro como predictor pronóstico en pacientes adultos con diagnóstico de COVID-19.

Background: Hyperchloremia has been associated with a greater presence of morbidity and mortality, mainly described in critically ill patients, this may be relative and absolute, which could be reflected in the sodium-chloride difference. Objective: The primary objective was to determine whether the sodium-chloride difference <31 mEq/L measured 24-48 hours after admission is a predictor of 28-day mortality in patients with COVID-19, and as secondary objectives to identify whether it is associated with higher requirement for invasive mechanical ventilation, presence of acute kidney injury and longer hospital stay. Material and methods: Retrospective, descriptive and analytical longitudinal cohort study, was done including all consecutive patients older than 16 years of any gender, admitted to the UMAE from March 1, 2020 to March 2021, which present a diagnosis of COVID-19 with RT-PCR test for SARS-CoV-2 positive. Results: A total of 722 patients were included, the difference sodium-chloride < 31 mEq/L is not associated with an increased risk of death at 28 days (p = 1.172, OR: 1.35; 95%CI, 0.87-2.08) or requirement of mechanical ventilation (p = 0.47, OR: 1.19; 95%CI, 0.76-1.86), but is associated with a higher risk of AKI (p < 0.05, OR: 2.04; 95%CI, 1.33- 3.14) and longer hospital stay (p < 0.05). Conclusions: the sodium-chloride difference < 31 mEq/L in the first hours of admission is associated with a higher risk of presenting acute kidney injury during hospital stay in patients with COVID-19, as well as a longer hospital stay.

Introducción: la hipercloremia se ha asociado a mayor presencia de morbimortalidad principalmente en pacientes críticos, pudiendo esta ser relativa y absoluta, la cual se puede reflejar por medio de la diferencia sodio menos cloro. Objetivo: el objetivo primario fue determinar si la diferencia sodio menos cloro < 31 mEq/L medida a las 24-48 horas de ingreso es predictor de mortalidad a 28 días en pacientes con COVID-19, y como objetivos secundarios identificar si se asocia a mayor requerimiento de ventilación mecánica invasiva, presencia de lesión renal aguda y mayor estancia hospitalaria. Material y métodos: estudio de tipo cohorte longitudinal retrospectivo, descriptivo y analítico, se incluyeron todos los pacientes blanco de manera consecutiva mayores de 16 años de cualquier género, ingresados en la UMAE No. 1 del Bajío de marzo del 2020 a marzo 2021, los cuales presentan diagnóstico de COVID-19 con PCR para el ARN de Sars-Cov2 positiva. Resultados: se incluyeron en total 722 pacientes, la diferencia sodio menos cloro < 31 mEq/L no se asocia a incremento del riesgo de muerte a 28 días (p = 1.172, OR: 1.35; IC95%: 0.87-2.08) ni requerimiento de ventilación mecánica (p = 0.47, OR: 1.19; IC95%: 0.76-1.86), pero sí a mayor riesgo de presentación de LRA (p < 0.05, OR: 2.04; IC95%: 1.33- 3.14) y mayor estancia hospitalaria (p < 0.05). Conclusiones: la diferencia sodio menos cloro < 31 mEq/L en las primeras horas del ingreso se asocia a mayor riesgo de presentar lesión renal aguda durante la estancia hospitalaria en pacientes con la COVID-19, así como mayor tiempo de estancia hospitalaria.

Demonstration of local adaptation in maize landraces by reciprocal transplantation.

Populations are locally adapted when they exhibit higher fitness than foreign populations in their native habitat. Maize landrace adaptations to highland and lowland conditions are of interest to researchers and breeders. To determine the prevalence and strength of local adaptation in maize landraces, we performed a reciprocal transplant experiment across an elevational gradient in Mexico. We grew 120 landraces, grouped into four populations (Mexican Highland, Mexican Lowland, South American Highland, South American Lowland), in Mexican highland and lowland common gardens and collected phenotypes relevant to fitness and known highland-adaptive traits such as anthocyanin pigmentation and macrohair density. 67k DArTseq markers were generated from field specimens to allow comparisons between phenotypic patterns and population genetic structure. We found phenotypic patterns consistent with local adaptation, though these patterns differ between the Mexican and South American populations. Quantitative trait differentiation (Q ST) was greater than neutral allele frequency differentiation (F ST) for many traits, signaling directional selection between pairs of populations. All populations exhibited higher fitness metric values when grown at their native elevation, and Mexican landraces had higher fitness than South American landraces when grown in these Mexican sites. As environmental distance between landraces' native collection sites and common garden sites increased, fitness values dropped, suggesting landraces are adapted to environmental conditions at their natal sites. Correlations between fitness and anthocyanin pigmentation and macrohair traits were stronger in the highland site than the lowland site, supporting their status as highland-adaptive. These results give substance to the long-held presumption of local adaptation of New World maize landraces to elevation and other environmental variables across North and South America.

A B73×Palomero Toluqueño mapping population reveals local adaptation in Mexican highland maize.

Generations of farmer selection in the central Mexican highlands have produced unique maize varieties adapted to the challenges of the local environment. In addition to possessing great agronomic and cultural value, Mexican highland maize represents a good system for the study of local adaptation and acquisition of adaptive phenotypes under cultivation. In this study, we characterize a recombinant inbred line population derived from the B73 reference line and the Mexican highland maize variety Palomero Toluqueño. B73 and Palomero Toluqueño showed classic rank-changing differences in performance between lowland and highland field sites, indicative of local adaptation. Quantitative trait mapping identified genomic regions linked to effects on yield components that were conditionally expressed depending on the environment. For the principal genomic regions associated with ear weight and total kernel number, the Palomero Toluqueño allele conferred an advantage specifically in the highland site, consistent with local adaptation. We identified Palomero Toluqueño alleles associated with expression of characteristic highland traits, including reduced tassel branching, increased sheath pigmentation and the presence of sheath macrohairs. The oligogenic architecture of these three morphological traits supports their role in adaptation, suggesting they have arisen from consistent directional selection acting at distinct points across the genome. We discuss these results in the context of the origin of phenotypic novelty during selection, commenting on the role of de novo mutation and the acquisition of adaptive variation by gene flow from endemic wild relatives.

High-Throughput Analysis of Protein Turnover with Tandem Fluorescent Protein Timers.

Tandem fluorescent protein timers (tFTs) are versatile reporters of protein dynamics. A tFT consists of two fluorescent proteins with different maturation kinetics and provides a ratiometric readout of protein age, which can be exploited to follow intracellular trafficking, inheritance and turnover of tFT-tagged proteins. Here, we detail a protocol for high-throughput analysis of protein turnover with tFTs in yeast using fluorescence measurements of ordered colony arrays. We describe guidelines on optimization of experimental design with regard to the layout of colony arrays, growth conditions, and instrument choice. Combined with semi-automated genetic crossing using synthetic genetic array (SGA) methodology and high-throughput protein tagging with SWAp-Tag (SWAT) libraries, this approach can be used to compare protein turnover across the proteome and to identify regulators of protein turnover genome-wide.

Expresión génica de receptores ECA2 en cavidad bucal y glándulas salivales y su papel en la infección por SARS CoV2. Revisión de la literatura / Gene Expression of ECA2 Receptors in the Oral Cavity and Salivary Glands and Its Role in SARS CoV2 Infection. Literature Review

Resumen Los receptores ECA2 presentan una expresión génica importante en las células escamosas de la lengua y glándulas salivales, mecanismo que es conveniente para la inoculación de SARS CoV2 toda vez que busca hacer el complejo de ensamblaje mediante su glicoproteína o proteína espiga hacia el receptor ECA2 de la mucosa bucal. Una vez inoculado y favorecido por las proteasas es la llave que permite la entrada del virión en la célula huésped para su posterior replicación, aumento de carga viral y potencial desaminación e infección; los estomatólogos deben estar alerta de los mecanismos de infección en cavidad bucal para protección propia y de los pacientes que son atendidos por este personal de salud.

Abstract ECA2 receptors have an important gene expression in the squamous cells of the tongue and salivary glands, a mechanism that is convenient for the inoculation of SARS CoV2 since it seeks to make the assembly complex through its glycoprotein or spike protein towards the ECA2 receptor of the oral mucosa. Once inoculated and favored by proteases, it is the key that allows the entry of the virion into the host cell for its subsequent replication, increase of viral load and potential deamination and infection; dental professionals must be alert to the mechanisms of infection in the oral cavity for their own protection and that of the patients who are treated by this health personnel.

Monoclonal antibodies for the identification and purification of vNAR domains and IgNAR immunoglobulins from the horn shark Heterodontus francisci.

In addition to conventional antibodies, cartilaginous fish have evolved a distinctive type of immunoglobulin, designated as IgNAR, which lacks the light polypeptide chains and is composed entirely by heavy chains. IgNAR molecules can be manipulated by molecular engineering to produce the variable domain of a single heavy chain polypeptide (vNARs). These, together with the VHH camel domains, constitute the smallest naturally occurring domains able to recognize an antigen. Their special features, such as small size, long extended finger-like CDR3, and thermal and chemical stability, make them suitable candidates for biotechnological purposes. Here we describe the generation of two mouse monoclonal antibodies (MAbs), MAb 370-12 and MAb 533-10, that both specifically react with vNAR domains of the horn shark Heterodontus francisci. While the former recognizes a broad spectrum of recombinant vNAR proteins, the latter is more restricted. MAb 370-12 precipitated a single band from whole shark serum, which was identified as IgNAR by mass spectrometry. Additionally, we used MAb 370-12 to follow the IgNAR-mediated immune response of sharks during immunization protocols with two different antigens (complete cells and a synthethic peptide), thus corroborating that MAb 370-12 recognizes both isolated vNAR domains and whole IgNAR molecules. Both MAbs represent an affordable molecular, biochemical, and biotechnological tool in the field of shark single-domain antibodies.

Single domain antibodies: promising experimental and therapeutic tools in infection and immunity.

Antibodies are important tools for experimental research and medical applications. Most antibodies are composed of two heavy and two light chains. Both chains contribute to the antigen-binding site which is usually flat or concave. In addition to these conventional antibodies, llamas, other camelids, and sharks also produce antibodies composed only of heavy chains. The antigen-binding site of these unusual heavy chain antibodies (hcAbs) is formed only by a single domain, designated VHH in camelid hcAbs and VNAR in shark hcAbs. VHH and VNAR are easily produced as recombinant proteins, designated single domain antibodies (sdAbs) or nanobodies. The CDR3 region of these sdAbs possesses the extraordinary capacity to form long fingerlike extensions that can extend into cavities on antigens, e.g., the active site crevice of enzymes. Other advantageous features of nanobodies include their small size, high solubility, thermal stability, refolding capacity, and good tissue penetration in vivo. Here we review the results of several recent proof-of-principle studies that open the exciting perspective of using sdAbs for modulating immune functions and for targeting toxins and microbes.

Interaction of rotaviruses with Hsc70 during cell entry is mediated by VP5.

Rotavirus infection seems to be a multistep process in which the viruses are required to interact with several cell surface molecules to enter the cell. The virus spike protein VP4, which is cleaved by trypsin into two subunits, VP5 and VP8, is involved in some of these interactions. We have previously shown that the neuraminidase-sensitive rotavirus strain RRV initially attaches to a sialic acid-containing cell molecule through the VP8 subunit of VP4 and subsequently interacts with integrin alpha2beta1 through VP5. After these initial contacts, the virus interacts with at least two additional proteins located at the cell surface, the integrin alphavbeta3 and the heat shock cognate protein Hsc70. In this work, we have shown that rotavirus RRV and its neuraminidase-resistant variant nar3 interact with Hsc70 through a VP5 domain located between amino acids 642 and 658 of the protein. This conclusion is based on the observation that a recombinant protein comprising the 300 carboxy-terminal amino acids of VP5 binds specifically to Hsc70 and a synthetic peptide containing amino acids 642 to 658 competes with the binding of the RRV and nar3 viruses to the heat shock protein. The VP5 peptide also competed with the binding to Hsc70 of the recombinant VP5 protein, and an antibody to Hsc70 reduced the binding of the recombinant protein to the surface of MA104 cells. The fact that the synthetic peptide blocks the infectivity of rotaviruses RRV and nar3 but not their binding to cells indicates that the interaction of VP5 with Hsc70 most probably occurs at a postattachment step during the virus entry process.