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This paper studies impulsive dynamic Sturm-Liouville boundary value problems. The existence of a countably infinite set of eigenvalues and eigenfunctions is proved and a uniformly convergent expansion formula in the eigenfunctions is established.

Actinomycetes are a group of bacteria that have been reported as potential controllers of several plant pathogens and plant growth-promoting agents. This study focused on the isolation of 60 actinobacterial strains from the Cuatro Cienegas Basin, Coahuila, Mexico, with an emphasis on evaluating their potential as biocontrol agents against plant pathogens. Among the strains tested, the isolate PR69 exhibited significant in vitro antagonistic activity against eight plant pathogens, with inhibition rates ranging from 44% to 73%, including Phytophthora capsici. The genome of PR69 was sequenced and assembled. It was identified as Streptomyces by phylogenetic analysis based on concatenated multiple sequence alignments of 81 core bacterial genes. Additionally, volatile compounds produced by PR69 enhanced the growth of Arabidopsis thaliana seedlings in vitro, increasing seedling weight, primary root length, and the number of secondary roots. Furthermore, the soil treated with Streptomyces sp. PR69 effectively controlled the infection caused by the pathogen P. capsici in bell pepper plants, reducing mortality by 47% compared to plants inoculated solely with the pathogen. PR69-treated plants also showed 30% increase in fresh weight compared to untreated controls. These findings suggest that Streptomyces sp. PR69 holds promise as a bioinoculant for promoting pepper plant growth and controlling P. capsici populations.

ABSTRACT: Necrotic enteritis is a devastating disease to poultry caused by the bacterium Clostridium perfringens. As a novel approach to combating poultry necrotic enteritis, we identified and characterized several hundred single domain antibody fragments (or nanobodies) capable of binding either the NetB toxin or the collagen-binding adhesin (CnaA) of C. perfringens. Many of the nanobodies could neutralize the in vitro functions of NetB or CnaA with inhibitory concentrations in the nanomolar range. The nanobodies were also screened for proteolytic stability in an extract derived from gastrointestinal tract fluids of chickens. A collection of 6 nanobodies (4 targeting NetB and 2 targeting CnaA) with high neutralizing activity and high gastrointestinal tract extract stability were expressed and secreted by Pichia pastoris or Bacillus subtilis. Chickens were given a feed with 1 of the 2 nanobody-containing groups: 1) nanobody-containing P. pastoris supernatants that were semi-purified, lyophilized, and enterically coated, or 2) B. subtilis spores from strains containing the nanobody genes. Compared to untreated chickens (23.75% mortality), mortality of chickens receiving feed modified with the P. pastoris and B. subtilis products decreased to 11.25 and 7.5%, respectively. These results offer a new opportunity to improve the control of poultry necrotic enteritis by incorporating highly specific nanobodies or bacteria expressing these nanobodies directly into chicken feed.

Extracellular vesicles released by the protozoan parasite Leishmania display immunomodulatory properties towards mammalian immune cells. In this study, we have evaluated the potential of extracellular vesicles derived from the non-pathogenic protozoan Leishmania tarentolae towards the development of a vaccine adjuvant. As a proof of concept, we expressed in L. tarentolae a codon-optimized SARS-CoV-2 Spike protein fused to the L. mexicana secreted acid phosphatase signal peptide in the N-terminal and to a 6×-His stretch in the C-terminal. Extracellular vesicles released by the engineered L. tarentolae were isolated by ultracentrifugation and fast protein liquid chromatography and were characterized via nanoparticle tracking analysis and transmission electron microscopy. The recombinant S protein was present in extracellular vesicles released by L. tarentolae, as determined by Western blot analyses and immunoelectron microscopy. Next, we evaluated the immunomodulatory potential of extracellular vesicles containing the S protein towards bone-marrow-derived macrophages and bone-marrow-derived dendritic cells. Our data show that in bone-marrow-derived dendritic cells, extracellular vesicles containing the S protein induced an increased expression of proinflammatory genes compared to plain extracellular vesicles whereas the opposite was observed in bone-marrow-derived macrophages. These findings reveal the immunomodulatory potential of L. tarentolae extracellular vesicles and provide a proof of concept that they can be used as adjuvant in the context of dendritic cell stimulation.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune neurological disease characterized by the recurrent appearance of demyelinating lesions and progressive disability. Currently, there are multiple disease-modifying treatments, however, there is a significant need to develop new therapeutic targets, especially for the progressive forms of the disease. This review article provides an overview of the most recent studies aimed at understanding the inflammatory processes that are activated in response to the accumulation of kynurenine pathway (KP) metabolites, which exacerbate an imbalance between immune system cells (e.g., Th1, Th2, and T reg) and promote the release of pro-inflammatory interleukins that modulate different mechanisms: membrane-receptors function; nuclear factors expression; and cellular signals. Together, these alterations trigger cell death mechanisms in brain cells and promote neuron loss and axon demyelination. This hypothesis could represent a remarkable approach for disease-modifying therapies for MS. Here, we also provide a perspective on the repositioning of some already approved drugs involved in other signaling pathways, which could represent new therapeutic strategies for MS treatment.

Muscular dystrophies (MDs) are a heterogeneous group of diseases of genetic origin characterized by progressive skeletal muscle degeneration and weakness. There are several types of MDs, varying in terms of age of onset, severity, and pattern of the affected muscles. However, all of them worsen over time, and many patients will eventually lose their ability to walk. In addition to skeletal muscle effects, patients with MDs may present cardiac and respiratory disorders, generating complications that could lead to death. Interdisciplinary management is required to improve the surveillance and quality of life of patients with an MD. At present, pharmacological therapy is only available for Duchene muscular dystrophy (DMD)—the most common type of MD—and is mainly based on the use of corticosteroids. Other MDs caused by alterations in dystrophin-associated proteins (DAPs) are less frequent but represent an important group within these diseases. Pharmacological alternatives with clinical potential in patients with MDs and other proteins associated with dystrophin have been scarcely explored. This review focuses on drugs and molecules that have shown beneficial effects, mainly in experimental models involving alterations in DAPs. The mechanisms associated with the effects leading to promising results regarding the recovery or maintenance of muscle strength and reduction in fibrosis in the less-common MDs (i.e., with respect to DMD) are explored, and other therapeutic targets that could contribute to maintaining the homeostasis of muscle fibers, involving different pathways, such as calcium regulation, hypertrophy, and maintenance of satellite cell function, are also examined. It is possible that some of the drugs explored here could be used to affordably improve the muscular function of patients until a definitive treatment for MDs is developed.

The quest for microbial cellulases has intensified as a response to global challenges in biofuel production. The efficient deconstruction of lignocellulosic biomass holds promise for generating valuable products in various industries such as food, textile, and detergents. This article presents a systematic bioprospection aimed at isolating actinomycetes with exceptional cellulose deconstruction capabilities. Our methodology explored the biodiverse oligotrophic region of Cuatro Cienegas, Coahuila, within the Chihuahuan Desert. Among the evaluated actinomycetes collection, 78% exhibited cellulolytic activity. Through a meticulous screening process based on enzymatic index evaluation, we identified a highly cellulolytic Streptomyces strain for further investigation. Submerged fermentation of this strain revealed an endoglucanase enzymatic activity of 149 U/mg. Genomic analysis of strain Streptomyces sp. STCH565-A revealed unique configurations of carbohydrate-active enzyme (CAZyme) genes, underscoring its potential for lignocellulosic bioconversion applications. These findings not only highlight the significance of the Chihuahuan Desert as a rich source of cellulolytic microorganisms but also offer insights into the systematic exploration and selection of high-performing cellulolytic microorganisms for application in diverse environmental contexts. In conclusion, our bioprospecting study lays a foundation for harnessing the cellulolytic potential of actinomycetes from the Chihuahuan Desert, with implications for advancing cellulose deconstruction processes in various industries. The findings can serve as a blueprint for future bioprospecting efforts in different regions, facilitating the targeted discovery of microorganisms with exceptional cellulosic deconstruction capabilities.

Environmental pollution caused by petroleum-derived plastics continues to increase annually. Consequently, current research is interested in the search for eco-friendly bacterial polymers. The importance of Bacillus bacteria as producers of polyhydroxyalkanoates (PHAs) has been recognized because of their physiological and genetic qualities. In this study, twenty strains of Bacillus genus PHA producers were isolated. Production was initially evaluated qualitatively to screen the strains, and subsequently, the strain B12 or Bacillus sp. 12GS, with the highest production, was selected through liquid fermentation. Biochemical and molecular identification revealed it as a novel isolate of Bacillus cereus. Production optimization was carried out using the Taguchi methodology, determining the optimal parameters as 30 °C, pH 8, 150 rpm, and 4% inoculum, resulting in 87% and 1.91 g/L of polyhydroxybutyrate (PHB). Kinetic studies demonstrated a higher production within 48 h. The produced biopolymer was analyzed using Fourier-transform infrared spectroscopy (FTIR), confirming the production of short-chain-length (scl) polyhydroxyalkanoate, named PHB, and differential scanning calorimetry (DSC) analysis revealed thermal properties, making it a promising material for various applications. The novel B. cereus isolate exhibited a high %PHB, emphasizing the importance of bioprospecting, study, and characterization for strains with biotechnological potential.

ABSTRACT Pathogen-specific rewiring of host cell metabolism creates the metabolically adapted microenvironment required for pathogen replication. Here, we investigated the mechanisms governing the modulation of macrophage mitochondrial properties by the vacuolar pathogen Leishmania. We report that induction of oxidative phosphorylation and mitochondrial biogenesis by Leishmania donovani requires the virulence glycolipid lipophosphoglycan, which stimulates the expression of key transcriptional regulators and structural genes associated with the electron transport chain. Leishmania-induced mitochondriogenesis also requires a lipophosphoglycan-independent pathway involving type I interferon (IFN) receptor signaling. The observation that pharmacological induction of mitochondrial biogenesis enables an avirulent lipophosphoglycan-defective L. donovani mutant to survive in macrophages supports the notion that mitochondrial biogenesis contributes to the creation of a metabolically adapted environment propitious to the colonization of host cells by the parasite. This study provides novel insight into the complex mechanism by which Leishmania metacyclic promastigotes alter host cell mitochondrial biogenesis and metabolism during the colonization process. IMPORTANCE To colonize host phagocytes, Leishmania metacyclic promastigotes subvert host defense mechanisms and create a specialized intracellular niche adapted to their replication. This is accomplished through the action of virulence factors, including the surface coat glycoconjugate lipophosphoglycan. In addition, Leishmania induces proliferation of host cell mitochondria as well as metabolic reprogramming of macrophages. These metabolic alterations are crucial to the colonization process of macrophages, as they may provide metabolites required for parasite growth. In this study, we describe a new key role for lipophosphoglycan in the stimulation of oxidative phosphorylation and mitochondrial biogenesis. We also demonstrate that host cell pattern recognition receptors Toll-like receptor 4 (TLR4) and endosomal TLRs mediate these Leishmania-induced alterations of host cell mitochondrial biology, which also require type I IFN signaling. These findings provide new insight into how Leishmania creates a metabolically adapted environment favorable to their replication.

The language of advertising is unique and very peculiar in comparison with other elements of media discourse. The effectiveness of speech in advertising media discourse focuses on catching the attention of the target audience. Since the language of advertising is characterized by a distinguished persuasive function, the creators of ads spare no effort to make them catchy, interesting and witty. This is the reason why various linguistic devices are used to facilitate the comprehension and memorization of advertisements. In this regard, wordplay plays a significant role as the intentional usage of puns ensures the effectiveness of the composed texts.

En este artículo se analiza un grupo de errores en el aprendizaje del maya (Península de Yucatán, México), obtenidos en un medio escolarizado. Se establece una clasificación basada en sus características lingüísticas, la modalidad de producción (oralidad, audición, escritura), su frecuencia y su aceptación social. Se propone, igualmente, una comparación entre el nivel de familiaridad que tiene el estudiantado con la lengua, ya que para algunos de los individuos es una lengua de herencia (Polinsky y Kagan, 2007), en estadios diferenciados, tanto fuera como dentro del territorio en el que se habla. Se sugiere que se presenta una interacción jerárquica entre niveles, que si no es atendida, el error no será productivo. Se advierte que este tipo de estudios (centrados en una lengua indígena) son escasos e importantes para los contextos en los que se implementan medidas que contribuyen al mantenimiento y fortalecimiento de lenguas en una condición de minorización.

Arbuscular mycorrhizal fungi (AMF) colonization, sampled at 32–50 days post-inoculation (dpi), was significantly reduced in suppressor of prosystemin-mediated responses2 (spr2) mutant tomato plants impaired in the ω−3 FATTY ACID DESATURASE7 (FAD7) gene that limits the generation of linolenic acid and, consequently, the wound-responsive jasmonic acid (JA) burst. Contrary to wild-type (WT) plants, JA levels in root and leaves of spr2 mutants remained unchanged in response to AMF colonization, further supporting its regulatory role in the AM symbiosis. Decreased AMF colonization in spr2 plants was also linked to alterations associated with a disrupted FAD7 function, such as enhanced salicylic acid (SA) levels and SA-related defense gene expression and a reduction in fatty acid content in both mycorrhizal spr2 roots and leaves. Transcriptomic data revealed that lower mycorrhizal colonization efficiency in spr2 mutants coincided with the modified expression of key genes controlling gibberellin and ethylene signaling, brassinosteroid, ethylene, apocarotenoid and phenylpropanoid synthesis, and the wound response. Targeted metabolomic analysis, performed at 45 dpi, revealed augmented contents of L-threonic acid and DL-malic acid in colonized spr2 roots which suggested unfavorable conditions for AMF colonization. Additionally, time- and genotype-dependent changes in root steroid glycoalkaloid levels, including tomatine, suggested that these metabolites might positively regulate the AM symbiosis in tomato. Untargeted metabolomic analysis demonstrated that the tomato root metabolomes were distinctly affected by genotype, mycorrhizal colonization and colonization time. In conclusion, reduced AMF colonization efficiency in spr2 mutants is probably caused by multiple and interconnected JA-dependent and independent gene expression and metabolomic alterations.

With the purpose of discovering new anticancer molecules that might have fewer side effects or reduce resistance to current antitumor drugs, a bioprospecting study of the microalgae of the Cuatro Cienegas Basin (CCB), an oasis in the Chihuahuan desert in Mexico was conducted. A microalgae was identified as Granulocystopsis sp. through sequencing the rbcL gene and reconstruction of a phylogenetic tree, and its anticancer activities were assessed using various in vitro assays and different cell lines of human cancers, including lung, skin melanoma, colorectal, breast and prostatic cancers, as well as a normal cell line. The values of IC50 of the microalgae methanolic extract using the MTT assay were lower than 20 μg/ml, except that in the lung cancer line and the normal cell line. In vitro, the microalgae extract caused the loss of membrane integrity, monitored by the trypan blue exclusion test and exhibited marked inhibition of adhesion and cell proliferation in cancer cell lines, through the evaluation of the clonogenic assay. Also, typical nuclear changes of apoptotic processes were observed under the microscope, using the dual acridine orange/ethidium bromide fluorescent staining. Finally, the microalgae extract increased the activity of caspases 3 and 7 in skin melanoma, colon, breast and prostate cancer cells, in the same way as the apoptotic inductor and powerful antitumoral drug, doxorubicin. This study shows the anticancer activity from Granulocystopsis sp., a microalgae isolated from the CCB.

El síndrome primario de la silla turca vacía o aracnoidocele selar se presenta cuando una de las capas que cubre la parte externa del cerebro protruye hacia abajo en la silla y ejerce presión sobre la hipófisis. En el caso del hipopituitarismo, como causa de aracnoidocele, las manifestaciones clínicas dependen del aumento o disminución de la producción de hormonas, lo que lleva a la aparición de trastornos hidrominerales severos como la hiponatremia. Se presenta el caso de una paciente que acudió al Hospital Dr. Gustavo Aldereguía Lima con cuadro clínico de vómitos, decaimiento, malestar general, pérdida del apetito y ureas escasas. Durante su ingreso, la paciente presentó un cuadro de estado convulsivo que llevó a la ventilación mecánica. Se realizaron estudios tomográficos que fueron negativos y al analizar el resto de los exámenes de laboratorio, se diagnosticó un hipotiroidismo con hiponatremia severa para lo cual se indicó tratamiento. Se realizó una resonancia magnética nuclear donde se determinó un aracnoidocele selar grado III. Se presenta este reporte por la importancia del diagnóstico y tratamiento oportunos de esta entidad.

Abstract Background Thevetia peruviana (Pers.) K. Schum or Cascabela peruviana (L.) Lippold (commonly known as ayoyote, codo de fraile, lucky nut, or yellow oleander), native to Mexico and Central America, is a medicinal plant used traditionally to cure diseases like ulcers, scabies, hemorrhoids and dissolve tumors. The purpose of this study was to evaluate the cytotoxic, antiproliferative and apoptotic activity of methanolic extract of T. peruviana fruits on human cancer cell lines. Methods The cytotoxic activity of T. peruviana methanolic extract was carried out on human breast, colorectal, prostate and lung cancer cell lines and non-tumorigenic control cells (fibroblast and Vero), using the MTT assay. For proliferation and motility, clonogenic and wound-healing assays were performed. Morphological alterations were monitored by trypan blue exclusion, as well as DNA fragmentation and AO/EB double staining was performed to evaluate apoptosis. The extract was separated using flash chromatography, and the resulting fractions were evaluated on colorectal cancer cells for their cytotoxic activity. The active fractions were further analyzed through mass spectrometry. Results The T. peruviana methanolic extract exhibited cytotoxic activity on four human cancer cell lines: prostate, breast, colorectal and lung, with values of IC50 1.91 ± 0.76, 5.78 ± 2.12, 6.30 ± 4.45 and 12.04 ± 3.43 μg/mL, respectively. The extract caused a significant reduction of cell motility and colony formation on all evaluated cancer cell lines. In addition, morphological examination displayed cell size reduction, membrane blebbing and detachment of cells, compared to non-treated cancer cell lines. The T. peruviana extract induced apoptotic cell death, which was confirmed by DNA fragmentation and AO/EB double staining. Fractions 4 and 5 showed the most effective cytotoxic activity and their MS analysis revealed the presence of the secondary metabolites: thevetiaflavone and cardiac glycosides. Conclusion T. peruviana extract has potential as natural anti-cancer product with critical effects in the proliferation, motility, and adhesion of human breast and colorectal cancer cells, and apoptosis induction in human prostate and lung cancer cell lines, with minimal effects on non-tumorigenic cell lines.

The urgency of the research is caused by the wide application of Drazin generalized inverse matrix in the theory of finite Markov chains, in solving linear shifting system of differential equations, difference equations, problems of optimal control of dynamic systems; in several aspects of automated control systems, etc. The main aim of the study is to develop an algorithm for finding matrix discretes of single-parametric Drazin generalized inverse matrix in the field of differential transformations and restoring the original using reverse D-transformations. The methods used in the study: theory of numerical Drazin pseudoinverse matrices, theory of generalized parametric inverse matrices, matrix full rank factorization, direct and reverse differential transformations, linear transformations of vector space, linear algebra, numerical calculations of matrix discretes using MATLAB ver. R2011b software package. The results: The paper introduces rather simple numerical-analytical method for determining Drazin single-parametric generalized inverse matrix which can be easily implemented by means of contemporary information technologies. The illustration of the method by a single sample example for determining a special case of Drazin generalized inverse matrix - group inverse matrix, proved its computational efficiency and low computational error ratio.