Efficacy of Entomopathogenic Staphylococcus Bacteria as a Biocontrol Agent against Rhipicephalus microplus Ticks: Assessing Reproductive Inhibition and Mortality Rates.

Rhipicephalus microplus is a persistent ectoparasite of cattle that causes bovine anaplasmosis and babesiosis, causing economic losses worldwide. Chemical treatment is the primary method for tick control, but the emergence of pesticide-resistant ticks is a major challenge. Alternative biocontrol strategies utilizing entomopathogenic microorganisms are being explored. This study aimed to validate the species identification and assess the efficacy of four strains of Staphylococcus bacteria (S. shinii S1 and S-2, S. succinus, and S. xylosus) previously reported as being entomopathogenic to R. microplus ticks. According to the bioassays, S. shinii S-1 exhibited the greatest degree of reproductive inhibition (47%), followed by S. succinus (44.3%) at a concentration of 1 × 108 cfu/mL. S. xylosus displayed decreased reproductive inhibition (6.3%). In an additional bioassay, S. shinii S-1 exhibited a significant larval mortality of 67.63%, followed by S. succinus with 66.75%, S. shinni S-2 with 64.61%, and S. xylosus with 28.18% mortality. The common signs of infection observed on these ticks included swelling, yellowish exudate on the hypostome, and reduced limb mobility and color change, except for S. succinus, which did not cause color changes. These bacteria were naturally found on bovine skin. However, further studies are needed to confirm their potential as promising alternatives or complementary agents to existing acaricidal compounds.

Relationship between acaricide resistance and acetylcholinesterase gene polymorphisms in the cattle tick Rhipicephalus microplus.

In this study, we aimed to develop a comprehensive methodology for identifying amino acid polymorphisms in acetylcholinesterase transcript 2 (AChE2) in acaricide-resistant Rhipicephalus microplus ticks. This included assessing AChE2 expression levels through qPCR and conducting 3D modeling to evaluate the interaction between acaricides and AChE2 using docking techniques. The study produced significant results, demonstrating that acaricide-resistant R. microplus ticks exhibit significantly higher levels of AChE expression than susceptible reference ticks. In terms of amino acid sequence, we identified 9 radical amino acid substitutions in AChE2 from acaricide-resistant ticks, when compared to the gene sequence of the susceptible reference strain. To further understand the implications of these substitutions, we utilized 3D acaricide-AChE2 docking modeling to examine the interaction between the acaricide and the AChE2 catalytic site. Our models suggest that these amino acid polymorphisms alter the configuration of the binding pocket, thereby contributing to differences in acaricide interactions and ultimately providing insights into the acaricide-resistance phenomenon in R. microplus.

Title: Relations entre la résistance aux acaricides et les polymorphismes du gène de l'acétylcholinestérase chez la tique du bétail Rhipicephalus microplus. Abstract: Notre étude vise à développer une méthodologie complète pour identifier les polymorphismes d'acides aminés dans le transcrit 2 de l'acétylcholinestérase (AChE2) chez les tiques Rhipicephalus microplus résistantes aux acaricides. Cela comprend l'évaluation des niveaux d'expression d'AChE2 via qPCR et la réalisation d'une modélisation 3D pour évaluer l'interaction entre les acaricides et l'AChE2 à l'aide de techniques d'amarrage moléculaire. L'étude a produit des résultats significatifs, démontrant que les tiques R. microplus résistantes aux acaricides présentent des niveaux d'expression d'AChE significativement plus élevés que les tiques sensibles de référence. En termes de séquence d'acides aminés, nous avons identifié 9 substitutions d'acides aminés dans AChE2 provenant de tiques résistantes aux acaricides par rapport à la séquence génétique de la souche sensible de référence. Pour mieux comprendre les implications de ces substitutions, nous avons utilisé la modélisation de l'amarrage acaricide-AChE2 pour examiner l'interaction entre l'acaricide et le site catalytique AChE2. Nos modèles suggèrent que ces polymorphismes d'acides aminés modifient la configuration de la poche de liaison, contribuant ainsi aux différences dans les interactions acaricides et fournissant finalement un aperçu du phénomène de résistance aux acaricides chez R. microplus.

Superoxide dismutase 2 deficiency is associated with enhanced central chemoreception in mice: Implications for breathing regulation.

AIMS: In mammals, central chemoreception plays a crucial role in the regulation of breathing function in both health and disease conditions. Recently, a correlation between high levels of superoxide anion (O2.-) in the Retrotrapezoid nucleus (RTN), a main brain chemoreceptor area, and enhanced central chemoreception has been found in rodents. Interestingly, deficiency in superoxide dismutase 2 (SOD2) expression, a pivotal antioxidant enzyme, has been linked to the development/progression of several diseases. Despite, the contribution of SOD2 on O2.- regulation on central chemoreceptor function is unknown. Accordingly, we sought to determine the impact of partial deletion of SOD2 expression on i) O2.-accumulation in the RTN, ii) central ventilatory chemoreflex function, and iii) disordered-breathing. Finally, we study cellular localization of SOD2 in the RTN of healthy mice. METHODS: Central chemoreflex drive and breathing function were assessed in freely moving heterozygous SOD2 knockout mice (SOD2+/- mice) and age-matched control wild type (WT) mice by whole-body plethysmography. O2.- levels were determined in RTN brainstem sections and brain isolated mitochondria, while SOD2 protein expression and tissue localization were determined by immunoblot, RNAseq and immunofluorescent staining, respectively. RESULTS: Our results showed that SOD2+/- mice displayed reductions in SOD2 levels and high O2.- formation and mitochondrial dysfunction within the RTN compared to WT. Additionally, SOD2+/- mice displayed a heightened ventilatory response to hypercapnia and exhibited overt signs of altered breathing patterns. Both, RNAseq analysis and immunofluorescence co-localization studies showed that SOD2 expression was confined to RTN astrocytes but not to RTN chemoreceptor neurons. Finally, we found that SOD2+/- mice displayed alterations in RTN astrocyte morphology compared to RTN astrocytes from WT mice. INNOVATION & CONCLUSION: These findings provide first evidence of the role of SOD2 in the regulation of O2.- levels in the RTN and its potential contribution on the regulation of central chemoreflex function. Our results suggest that reductions in the expression of SOD2 in the brain may contribute to increase O2.- levels in the RTN being the outcome a chronic surge in central chemoreflex drive and the development/maintenance of altered breathing patterns. Overall, dysregulation of SOD2 and the resulting increase in O2.- levels in brainstem respiratory areas can disrupt normal respiratory control mechanisms and contribute to breathing dysfunction seen in certain disease conditions characterized by high oxidative stress.

Single Amino Acid Polymorphisms in the Fasciola hepatica Carboxylesterase Type B Gene and Their Potential Role in Anthelmintic Resistance.

The expression of the Fasciola hepatica carboxylesterase type B (CestB) gene is known to be induced upon exposure to the anthelmintic triclabendazole (TCBZ), leading to a substantial rise in enzyme-specific activity. Furthermore, the nucleotide sequence of the CestB gene displays variations that can potentially result in radical amino acid substitutions at the ligand binding site. These substitutions hold the potential to impact both the ligand-protein interaction and the catalytic properties of the enzyme. Thus, the objective of our study was to identify novel CestB polymorphisms in TCBZ-resistant parasites and field isolates obtained from a highly endemic region in Central Mexico. Additionally, we aimed to assess these amino acid polymorphisms using 3D modeling against the metabolically oxidized form of the anthelmintic TCBZSOX. Our goal was to observe the formation of TCBZSOX-specific binding pockets that might provide insights into the role of CestB in the mechanism of anthelmintic resistance. We identified polymorphisms in TCBZ-resistant parasites that exhibited three radical amino acid substitutions at positions 147, 215, and 263. These substitutions resulted in the formation of a TCBZSOX-affinity pocket with the potential to bind the anthelmintic drug. Furthermore, our 3D modeling analysis revealed that these amino acid substitutions also influenced the configuration of the CestB catalytic site, leading to alterations in the enzyme's interaction with chromogenic carboxylic ester substrates and potentially affecting its catalytic properties. However, it is important to note that the TCBZSOX-binding pocket, while significant for drug binding, was located separate from the enzyme's catalytic site, rendering enzymatic hydrolysis of TCBZSOX impossible. Nonetheless, the observed increased affinity for the anthelmintic may provide an explanation for a drug sequestration type of anthelmintic resistance. These findings lay the groundwork for the future development of a molecular diagnostic tool to identify anthelmintic resistance in F. hepatica.

An alternative vaccine target for bovine Anaplasmosis based on enolase, a moonlighting protein.

The discovery of new targets for preventing bovine anaplasmosis has moved away from focusing on proteins that have already been extensively studied in Anaplasma marginale, including the Major Surface Proteins, Outer Membrane Proteins, and Type IV Secretion System proteins. An alternative is moonlighting or multifunctional proteins, capable of performing various biological functions within various cellular compartments. There are several reports on the role of moonlighting proteins as virulence factors in various microorganisms. Moreover, it is known that about 25% of all moonlighting is involved in the virulence of pathogens. In this work, for the first time, we present the identification of three enolase proteins (AmEno01, AmEno15, and AmEno31) in the genome of Mexican strains of A. marginale. Using bioinformatics tools, we predicted the catalytic domains, enolase signature, and amino acids binding magnesium ion of the catalytic domain and performed a phylogenetic reconstruction. In addition, by molecular docking analysis, we found that AmEno01 would bind to erythrocyte proteins spectrin, ankyrin, and stomatin. This adhesion function has been reported for enolases from other pathogens. It is considered a promising target since blocking this function would impede the fundamental adhesion process that facilitates the infection of erythrocytes. Additionally, molecular docking predicts that AmEno01 could bind to extracellular matrix protein fibronectin, which would be significant if we consider that some proteins with fibronectin domains are localized in tick gut cells and used as an adhesion strategy to gather bacteria before traveling to salivary glands. Derived from the molecular docking analysis of AmEno01, we hypothesized that enolases could be proteins driven by the pathogen and redirected at the expense of the pathogen's needs.

A Novel Rhipicephalus microplus Estrogen Related Receptor (RmERR), a Molecular and In Silico Characterization of a Potential Protein Binding Estrogen.

The search for targets to control ticks and tick-borne diseases has been an ongoing problem, and so far, we still need efficient, non-chemical alternatives for this purpose. This search must consider new alternatives. For example genomics analysis is a widely applied tool in veterinary health studies to control pathogens. On the other hand, we propose that regulation of endocrine mechanisms represents a feasible alternative to biologically controlling tick infestations. Thus, we performed the molecular identification of an estrogen-related receptor gene of Rhipicephalus microplus called RmERR by RT-PCR in tick ovaries, embryonic cells, and hemolymph, which allowed us to analyze its expression and propose potential functions in endocrine mechanisms and developmental stages. In addition, we performed an in silico characterization to explore the molecular interactions of RmERR with different estrogens, estrogenic antagonists, and endocrine disruptor Bisphenol A (BPA), finding potential interactions predicted by docking analysis and supported by negative values of ΔG (which suggests the potential interaction of RmERR with the molecules evaluated). Additionally, phylogenetic reconstruction revealed that RmERR is grouped with other tick species but is phylogenetically distant from host vertebrates' ERRs. In summary, this study allowed for the identification of an ERR in cattle tick R. microplus for the first time and suggested its interaction with different estrogens, supporting the idea of a probable transregulation process in ticks. The elucidation of this interaction and its mechanisms unveiled its potential as a target to develop tick control strategies.

Chronic intermittent hypoxia promotes glomerular hyperfiltration and potentiates hypoxia-evoked decreases in renal perfusion and PO2.

Introduction: Sleep apnea (SA) is highly prevalent in patients with chronic kidney disease and may contribute to the development and/or progression of this condition. Previous studies suggest that dysregulation of renal hemodynamics and oxygen flux may play a key role in this process. The present study sought to determine how chronic intermittent hypoxia (CIH) associated with SA affects regulation of renal artery blood flow (RBF), renal microcirculatory perfusion (RP), glomerular filtration rate (GFR), and cortical and medullary tissue PO2 as well as expression of genes that could contribute to renal injury. We hypothesized that normoxic RBF and tissue PO2 would be reduced after CIH, but that GFR would be increased relative to baseline, and that RBF, RP, and tissue PO2 would be decreased to a greater extent in CIH vs. sham during exposure to intermittent asphyxia (IA, FiO2 0.10/FiCO2 0.03). Additionally, we hypothesized that gene programs promoting oxidative stress and fibrosis would be activated by CIH in renal tissue. Methods: All physiological variables were measured at baseline (FiO2 0.21) and during exposure to 10 episodes of IA (excluding GFR). Results: GFR was higher in CIH-conditioned vs. sham (p < 0.05), whereas normoxic RBF and renal tissue PO2 were significantly lower in CIH vs. sham (p < 0.05). Reductions in RBF, RP, and renal tissue PO2 during IA occurred in both groups but to a greater extent in CIH (p < 0.05). Pro-oxidative and pro-fibrotic gene programs were activated in renal tissue from CIH but not sham. Conclusion: CIH adversely affects renal hemodynamic regulation and oxygen flux during both normoxia and IA and results in changes in renal tissue gene expression.

Enhanced Peripheral Chemoreflex Drive Is Associated with Cardiorespiratory Disorders in Mice with Coronary Heart Disease.

Coronary heart disease (CHD) is a prevalent cardiovascular disease characterized by coronary artery blood flow reductions caused by lipid deposition and oxidation within the coronary arteries. Dyslipidemia is associated with local tissue damage by oxidative stress/inflammation and carotid bodies (CB) peripheral chemoreceptors are heavily modulated by both reactive oxygen species and pro-inflammatory molecules (i.e., cytokines). Despite this, it is not know whether CB-mediated chemoreflex drive may be affected in CHD. In the present study, we evaluated peripheral CB-mediated chemoreflex drive, cardiac autonomic function, and the incidence of breathing disorders in a murine model of CHD. Compared to age-matched control mice, CHD mice showed enhanced CB-chemoreflex drive (twofold increase in the hypoxic ventilatory response), cardiac sympathoexcitation, and irregular breathing disorders. Remarkably, all these were closely linked to the enhanced CB-mediated chemoreflex drive. Our results showed that mice with CHD displayed an enhanced CB chemoreflex, sympathoexcitation, and disordered breathing and suggest that CBs may be involved in chronic cardiorespiratory alterations in the setting of CHD.

Lipid-Encapsuled Grape Tannins Prevent Oxidative-Stress-Induced Neuronal Cell Death, Intracellular ROS Accumulation and Inflammation.

The central nervous system (CNS) is particularly vulnerable to oxidative stress and inflammation, which affect neuronal function and survival. Nowadays, there is great interest in the development of antioxidant and anti-inflammatory compounds extracted from natural products, as potential strategies to reduce the oxidative/inflammatory environment within the CNS and then preserve neuronal integrity and brain function. However, an important limitation of natural antioxidant formulations (mainly polyphenols) is their reduced in vivo bioavailability. The biological compatible delivery system containing polyphenols may serve as a novel compound for these antioxidant formulations. Accordingly, in the present study, we used liposomes as carriers for grape tannins, and we tested their ability to prevent neuronal oxidative stress and inflammation. Cultured catecholaminergic neurons (CAD) were used to establish the potential of lipid-encapsulated grape tannins (TLS) to prevent neuronal oxidative stress and inflammation following an oxidative insult. TLS rescued cell survival after H2O2 treatment (59.4 ± 8.8% vs. 90.4 ± 5.6% H2O2 vs. TLS+ H2O2; p < 0.05) and reduced intracellular ROS levels by ~38% (p < 0.05), despite displaying negligible antioxidant activity in solution. Additionally, TLS treatment dramatically reduced proinflammatory cytokines' mRNA expression after H2O2 treatment (TNF-α: 400.3 ± 1.7 vs. 7.9 ± 1.9-fold; IL-1ß: 423.4 ± 1.3 vs. 12.7 ± 2.6-fold; p < 0.05; H2O2 vs. TLS+ H2O2, respectively), without affecting pro/antioxidant biomarker expression, suggesting that liposomes efficiently delivered tannins inside neurons and promoted cell survival. In conclusion, we propose that lipid-encapsulated grape tannins could be an efficient tool to promote antioxidant/inflammatory cell defense.

An Update of Bovine Hemoplasmas Based on Phylogenetic and Genomics Analysis.

Mycoplasma wenyonii and 'Candidatus Mycoplasma haemobos' are bacteria that have been described as significant hemoplasmas that infect cattle worldwide. Currently, three bovine hemoplasma genomes are known. This work aimed to describe the main genomic characteristics and the evolutionary relationships between hemoplasmas, and provide a list of epitopes predicted by immunoinformatics as diagnostic candidates for bovine hemoplasmosis. Thus far, there is no vaccine to prevent this disease that economically impacts cattle production worldwide. Additionally, there is a lack of vaccines against bovine hemoplasmosis. In this work, we performed a genomic characterization of hemoplasmas, including two Mexican strains reported in bovines in the last few years. The generated information is a new scenario about the phylogeny of hemoplasmas. Also, we show genomic features among hemoplasmas that strengthen their characteristic genome plasticity of intracellular lifestyles. Finally, the elucidation of antigenic proteins in Mexican strains represents an opportunity to develop molecular detection methods and diagnoses.

A Single Nucleotide Polymorphism Translates into a Radical Amino Acid Substitution at the Ligand-Binding Site in Fasciola hepatica Carboxylesterase B.

Fasciola hepatica anthelmintic resistance may be associated with the catalytic activity of xenobiotic metabolizing enzymes. The gene expression of one of these enzymes, identified as carboxylesterase B (CestB), was previously described as inducible in adult parasites under anthelmintic treatment and exhibited a single nucleotide polymorphism at position 643 that translates into a radical amino acid substitution at position 215 from Glutamic acid to Lysine. Alphafold 3D models of both allelic sequences exhibited a significant affinity pocket rearrangement and different ligand-docking modeling results. Further bioinformatics analysis confirmed that the radical amino acid substitution is located at the ligand affinity site of the enzyme, affecting its affinity to serine hydrolase inhibitors and preferences for ester ligands. A field genotyping survey from parasite samples obtained from two developmental stages isolated from different host species from Argentina and Mexico exhibited a 37% allele distribution for 215E and a 29% allele distribution for 215K as well as a 34% E/K heterozygous distribution. No linkage to host species or geographic origin was found in any of the allele variants.

Peripheral chemoreflex modulation of renal hemodynamics and renal tissue PO2 in chronic heart failure with reduced ejection fraction.

Aberrant carotid body chemoreceptor (CBC) function contributes to increased sympathetic nerve activity (SNA) and reduced renal blood flow (RBF) in chronic heart failure (CHF). Intermittent asphyxia (IA) mimicking sleep apnea is associated with additional increases in SNA and may worsen reductions in RBF and renal PO2 (RPO2) in CHF. The combined effects of decreased RBF and RPO2 may contribute to biochemical changes precipitating renal injury. This study sought to determine the role of CBC activity on glomerular filtration rate (GFR), RBF and RPO2 in CHF, and to assess the additive effects of IA. Furthermore, we sought to identify changes in gene expression that might contribute to renal injury. We hypothesized that GFR, RBF, and RPO2 would be reduced in CHF, that decreases in RBF and RPO2 would be worsened by IA, and that these changes would be ameliorated by CBC ablation (CBD). Finally, we hypothesized that CHF would be associated with pro-oxidative pro-fibrotic changes in renal gene expression that would be ameliorated by CBD. CHF was induced in adult male Sprague Dawley rats using coronary artery ligation (CAL). Carotid body denervation was performed by cryogenic ablation. GFR was assessed in conscious animals at the beginning and end of the experimental period. At 8-weeks post-CAL, cardiac function was assessed via echocardiography, and GFR, baseline and IA RBF and RPO2 were measured. Renal gene expression was measured using qRT-PCR. GFR was lower in CHF compared to sham (p < 0.05) but CBD had no salutary effect. RBF and RPO2 were decreased in CHF compared to sham (p < 0.05), and this effect was attenuated by CBD (p < 0.05). RBF and RPO2 were reduced to a greater extent in CHF vs. sham during exposure to IA (p < 0.05), and this effect was attenuated by CBD for RBF (p < 0.05). Downregulation of antioxidant defense and fibrosis-suppressing genes was observed in CHF vs. sham however CBD had no salutary effect. These results suggest that aberrant CBC function in CHF has a clear modulatory effect on RBF during normoxia and during IA simulating central sleep apnea.

Mexican Strains of Anaplasma marginale: A First Comparative Genomics and Phylogeographic Analysis.

The One Health approach looks after animal welfare and demands constant monitoring of the strains that circulate globally to prevent outbreaks. Anaplasma marginale is the etiologic agent of bovine anaplasmosis and is endemic worldwide. This study aimed to analyze, for the first time, the genetic diversity of seven Mexican strains of A. marginale and their relationship with other strains reported. The main features of A. marginale were obtained by characterizing all 24 genomes reported so far. Genetic diversity and phylogeography were analyzed by characterizing the msp1a gene and 5'-UTR microsatellite sequences and constructing a phylogenetic tree with 540 concatenated genes of the core genome. The Mexican strains show 15 different repeat sequences in six MSP1a structures and have phylogeographic relationships with strains from North America, South America, and Asia, which confirms they are highly variable. Based on our results, we encourage the performance of genome sequencing of A. marginale strains to obtain a high assembly level of molecular markers and the performance of extensive phylogeographic analysis. Undoubtedly, genomic surveillance helps build a picture of how a pathogen changes and evolves in geographical regions. However, we cannot discard the study of relationships pathogens establish with ticks and how they have co-evolved to establish themselves as a successful transmission system.

Sleep dysregulation in sympathetic-mediated diseases: implications for disease progression.

The autonomic nervous system (ANS) plays an important role in the coordination of several physiological functions including sleep/wake process. Significant changes in ANS activity occur during wake-to-sleep transition maintaining the adequate cardiorespiratory regulation and brain activity. Since sleep is a complex homeostatic function, partly regulated by the ANS, it is not surprising that sleep disruption trigger and/or evidence symptoms of ANS impairment. Indeed, several studies suggest a bidirectional relationship between impaired ANS function (i.e. enhanced sympathetic drive), and the emergence/development of sleep disorders. Furthermore, several epidemiological studies described a strong association between sympathetic-mediated diseases and the development and maintenance of sleep disorders resulting in a vicious cycle with adverse outcomes and increased mortality risk. However, which and how the sleep/wake control and ANS circuitry becomes affected during the progression of ANS-related diseases remains poorly understood. Thus, understanding the physiological mechanisms underpinning sleep/wake-dependent sympathetic modulation could provide insights into diseases involving autonomic dysfunction. The purpose of this review is to explore potential neural mechanisms involved in both the onset/maintenance of sympathetic-mediated diseases (Rett syndrome, congenital central hypoventilation syndrome, obstructive sleep apnoea, type 2 diabetes, obesity, heart failure, hypertension, and neurodegenerative diseases) and their plausible contribution to the generation of sleep disorders in order to review evidence that may serve to establish a causal link between sleep disorders and heightened sympathetic activity.

Medullary astrocytes mediate irregular breathing patterns generation in chronic heart failure through purinergic P2X7 receptor signalling.

BACKGROUND: Breathing disorders (BD) (apnoeas/hypopneas, periodic breathing) are highly prevalent in chronic heart failure (CHF) and are associated with altered central respiratory control. Ample evidence identifies the retrotrapezoid nucleus (RTN) as an important chemosensitivity region for ventilatory control and generation of BD in CHF, however little is known about the cellular mechanisms underlying the RTN/BD relationship. Within the RTN, astrocyte-mediated purinergic signalling modulates respiration, but the potential contribution of RTN astrocytes to BD in CHF has not been explored. METHODS: Selective neuron and/or astrocyte-targeted interventions using either optogenetic and chemogenetic manipulations in the RTN of CHF rats were used to unveil the contribution of the RTN on the development/maintenance of BD, the role played by astrocytes in BD and the molecular mechanism underpinning these alterations. FINDINGS: We showed that episodic photo-stimulation of RTN neurons triggered BD in healthy rats, and that RTN neurons ablation in CHF animals eliminates BD. Also, we found a reduction in astrocytes activity and ATP bioavailability within the RTN of CHF rats, and that chemogenetic restoration of normal RTN astrocyte activity and ATP levels improved breathing regularity in CHF. Importantly, P"X/ P2X7 receptor (P2X7r) expression was reduced in RTN astrocytes from CHF rats and viral vector-mediated delivery of human P2X7 P2X7r into astrocytes increases ATP bioavailability and abolished BD. INTERPRETATION: Our results support that RTN astrocytes play a pivotal role on BD generation and maintenance in the setting CHF by a mechanism encompassing P2X7r signalling. FUNDING: This study was funded by the National Research and Development Agency of Chile (ANID).

Sexual Dimorphism of the Neuroimmunoendocrine Response in the Spleen during a Helminth Infection: A New Role for an Old Player?

The interaction of the nervous, immune, and endocrine systems is crucial in maintaining homeostasis in vertebrates, and vital in mammals. The spleen is a key organ that regulates the neuroimmunoendocrine system. The Taenia crassiceps mouse system is an excellent experimental model to study the complex host-parasite relationship, particularly sex-associated susceptibility to infection. The present study aimed to determine the changes in neurotransmitters, cytokines, sex steroids, and sex-steroid receptors in the spleen of cysticercus-infected male and female mice and whole parasite counts. We found that parasite load was higher in females in comparison to male mice. The levels of the neurotransmitter epinephrine were significantly decreased in infected male animals. The expression of IL-2 and IL-4 in the spleen was markedly increased in infected mice; however, the expression of Interleukin (IL)-10 and interferon (IFN)-γ decreased. We also observed sex-associated differences between non-infected and infected mice. Interestingly, the data show that estradiol levels increased in infected males but decreased in females. Our studies provide evidence that infection leads to changes in neuroimmunoendocrine molecules in the spleen, and these changes are dimorphic and impact the establishment, growth, and reproduction of T. crassiceps. Our findings support the critical role of the neuroimmunoendocrine network in determining sex-associated susceptibility to the helminth parasite.

Factores de riesgo asociados a hipoglucemia en recién nacidos / Risk factors associated with hypoglycemia in newborns

RESUMEN Se realizó un artículo de revisión narrativo para evaluar los factores de riesgo relacionados con la hipoglucemia en los recién nacidos. Los objetivos buscaron determinar la evidencia clínica de los factores de riesgo relacionados con la hipoglucemia neonatal y determinar el soporte fisiopatológico sobre los factores de riesgo implicados en el desarrollo de hipoglucemia en los recién nacidos. Se han realizado búsquedas literarias en Medline-Pubmed, SCOPUS e HINARI sobre artículos publicados hasta noviembre de 2021; Esto arrojó un total de 108 artículos. Se concluye que, aunque el cribado universal de hipoglucemia en recién nacidos asintomáticos y de bajo riesgo puede ser innecesario, existe evidencia de que la hipoglucemia puede causar anomalías en el desarrollo neurológico; siendo factores de riesgo maternos de hipoglucemia en neonatos tales como: diabetes gestacional, preeclampsia y obesidad gestacional; Los factores de riesgo del recién nacido para hipoglucemia neonatal son: sepsis, bajo peso al nacer y prematuridad.

ABSTRACT A review paper was written aiming to determine risk factors related with hypoglycemia in newborns. Objectives were to determine clinical evidence for neonatal hypoglycemia-related risk factors and to determine the pathophysiological support upon risk factors implicated in the occurrence of hypoglycemia in newborns. Searches were performed in Medline-Pubmed, SCOPU, and HINARI, looking for papers published up to November 2021. We obtained 108 papers. It was concluded that although universal screening for hypoglycemia in asymptomatic low-risk newborns could be unnecessary, there is evidence that hypoglycemia may cause abnormalities in neurological development. Maternal risk factors for neonatal hypoglycemia include gestational diabetes, preeclampsia, and gestational obesity. Risk factors in newborns include sepsis, low birth weight and prematurity.

A newly optimized protocol to extract high-quality hemolymph from the cattle tick Rhipicephalus microplus: Improving the old conditions.

Ticks are hematophagous ectoparasites with importance to animal and human health. In recent years, the study of ticks has had significant development, including immune response, vector-host interactions, physiological and multi-omics approaches. However, one of the main impediments is obtaining a significant amount of high-quality hemolymph. For this reason, we developed a protocol that allows obtaining up to 100 µl of hemolymph free of host blood per engorged tick. The technique consists of continuous hipocuticular punctures of the tick dorsum and an anticoagulant buffer that impedes hemolymph coagulation, allowing constant extravasation and ensuring high yields. Additionally, the hemocytes recovered with this protocol are intact and can be used for further analysis. The high-quality hemolymph obtained using this protocol and its applications will help to better understand the processes involving the hemolymph and its components. Although there are other hemolymph extraction protocols, the method developed here is very well suited for Rhipicephalus microplus, and in our experience, results in better yields and high-quality samples.