Thermal Gelation of Proteins from Cajanus cajan Influenced by pH and Ionic Strength.

Cajanus cajan [pigeon pea (PP)] is an important legume crop for subsistence agriculture and its seeds are an alternative plant-based protein source. PP protein isolates (PPI) are able to form heat-induced gels that could be used for food applications. The aim of this work was to study the influence of pH (2.1, 3.9, 6.3, and 8.3) and ionic strength (µ) (0.10 and 0.54) on thermal stability and thermal gelation of PPI obtained by alkaline extraction (pH 8.0) and isoelectric precipitation. Thermal stability of PPI changed with pH variation at low ionic strength (µ = 0.10), decreasing this dependence with the increase of ionic strength (µ = 0.54). At µ = 0.10, gelation capacity of PPI was lower at pH 2.1 and pH 3.9. These gels presented a coarse network, which entails low WHC. At pH 6.3 and pH 8.3, gels showed a solid-like character with a compact and homogeneous matrix, with better WHC. At µ = 0.54, gel formation was favoured at pH 2.1 and pH 3.9. G'20/G'95 ratio values and differential solubility results suggest that hydrogen bonds and electrostatic interactions could play an important role in gel formation at pH 6.3 and pH 8.3.

Botfly Parasitism on Two Primates of the Cebidae Family in Peru.

Botflies (Diptera:Oestridae) are a diverse group of insect parasites that affect various vertebrate species. There are previous reports of myiasis affecting wild primates in Central and South America; however, information about botfly parasitism in Peruvian primates is scarce. We present data from two Cebidae primate specimens: a rescued large-headed capuchin monkey (Sapajus macrocephalus) housed at Taricaya Rescue Center, in Tambopata, Peru, and a free-ranging white-fronted capuchin monkey (Cebus albifrons aequatorialis) inhabiting Cerros de Amotape National Park. The first specimen had a larva identified as Dermatobia hominis, whereas Cuterebra baeri larvae infested the second. In both cases we initially identified the parasite species through their morphologic features before confirming the identification with genetic analysis through the cytochrome C oxidase subunit 1 mitochondrial gene sequencing of the larvae. Further field studies on the primate-parasite dynamics are needed to understand the impact of botfly myiasis on primate populations.

SoxD genes are required for adult neural stem cell activation.

The adult neurogenic niche in the hippocampus is maintained through activation of reversibly quiescent neural stem cells (NSCs) with radial glia-like morphology (RGLs). Here, we show that the expression of SoxD transcription factors Sox5 and Sox6 is enriched in activated RGLs. Using inducible deletion of Sox5 or Sox6 in the adult mouse brain, we show that both genes are required for RGL activation and the generation of new neurons. Conversely, Sox5 overexpression in cultured NSCs interferes with entry in quiescence. Mechanistically, expression of the proneural protein Ascl1 (a key RGL regulator) is severely downregulated in SoxD-deficient RGLs, and Ascl1 transcription relies on conserved Sox motifs. Additionally, loss of Sox5 hinders the RGL activation driven by neurogenic stimuli such as environmental enrichment. Altogether, our data suggest that SoxD genes are key mediators in the transition of adult RGLs from quiescence to an activated mitotic state under physiological situations.

Comparative Study of Structural and Physicochemical Properties of Pigeon Pea (Cajanus cajan L.) Protein Isolates and its Major Protein Fractions.

Pigeon pea protein isolates (PPI) are an option to obtain a high yield of good quality proteins and represent a great potential for the food industry. In this work, physicochemical and structural properties of albumin (ALB), globulin (GLB), and PPI obtained at different pHs (8, 9, 10, and 11) were studied to deepen the knowledge of these proteins for future application. GLB presented protein aggregates and polypeptides characteristics of 7S vicilin subunits while ALB presented polypeptides with low molecular masses. GLB showed a more compact and less flexible structure than ALB fraction due to the distinct conformational characteristics found in DSC, fluorescence spectroscopy, Ho. These structural characteristics conferred GLB greater conformational stability (∆GH2O) than ALB fraction. The latter presented a higher proportion of ß-strand in aggregated structures. PPI11 showed the highest protein recovery, but the least So with more presence of protein aggregates with the least proportion of ß-strands in aggregated structures. A higher percentage of protein unfolding and exposure of hydrophobic residues to solvent was observed as the extraction pH of the isolates increased. Enthalpy change of transition decreased, and the maximum emission wavelength shifted to red in fluorescence spectroscopy. However, PPI11 showed only a slight increase in Ho (10%) with respect to PPI8. The variation in pH for protein extraction constitutes a simple, rapid, and low-cost method to obtain PPI with physicochemical and structural properties that will determine its functional properties and their use as food ingredients.

Recommendations for airway management in a suspected or confirmed case with COVID-19. A protocol of the Department of Cardiovascular Anesthesia of the National Institute of Cardiology Ignacio Chávez / Recomendaciones para el manejo de la vía aérea en caso sospechoso y/o confirmado con COVID-19. Protocolo del Departamento de Anestesiología Cardiovascular del Instituto Nacional de Cardiología Ignacio Chávez

The new coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), detected in Wuhan, China, causes coronavirus disease 2019 (COVID-19), which was declared pandemic, and has caused more than 19 million confirmed cases and more than 700 thousand deaths worldwide. When our institution was converted to COVID's hospital since early April 2020, specific care protocols were developed, with the aim of improving the quality of care and safety of patients and the staff involved in their management. Airway management represents one of the highest risks of direct contact infection with aerosol generation (orotracheal intubation, secretion aspiration, extubation, cardiopulmonary resuscitation, high flow oxygen therapy, noninvasive ventilation, and invasive ventilation). We present the current recommendations for airway management as well as a step-by-step airway management protocol to carry out a more secure procedure based on the literature reported so far.

El nuevo coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), detectado en Wuhan (China), causante de la enfermedad por coronavirus 2019 (COVID-19), que se declaró como pandemia, ha causado más de 19 millones de casos confirmados y más de 700 mil muertes en el mundo. Nuestra institución se reconvirtió a hospital COVID desde principios de abril del 2020, con lo que se desarrollaron protocolos de atención específicos, con el objetivo de mejorar la calidad de atención y seguridad de los pacientes y el personal involucrado en su manejo. El manejo de la vía aérea representa uno de los riesgos más altos de contagio por contacto directo en la generación de aerosoles (intubación orotraqueal, aspiración de secreciones, extubación, resucitación cardiopulmonar, terapia de oxígeno de alto flujo, ventilación no invasiva y ventilación invasiva). Presentamos las recomendaciones actuales para el manejo de la vía aérea, así como un protocolo de manejo paso a paso para llevar a cabo un procedimiento con mayor seguridad basados en la literatura reportada hasta el momento.

Amaranth as a Source of Antihypertensive Peptides.

Amaranth is an ancestral crop used by pre-Columbian cultures for 6000 to 8000 years. Its grains have a relevant chemical composition not only from a nutritional point of view but also due to the contribution of components with good techno-functional properties and important potential as bioactive compounds. Numerous studies have shown that amaranth storage proteins possess encrypted sequences that, once released, exhibit different physiological activities. One of the most studied is antihypertensive activity. This review summarizes the progress made over the last years (2008-2020) related to this topic. Studies related to inhibition of different enzymes of the Renin-Angiotensin-Aldosterone system, in particular Angiotensin Converting Enzyme (ACE) and Renin, as well as those referring to potential modulation mechanisms of tissue or local Renin-Angiotensin-Aldosterone system, are analyzed, including in silico, in vitro, in vivo, and ex vivo assays. Furthermore, the potential use of these bioactive peptides or products containing them, in the elaboration of functional food matrices is discussed. Finally, the most relevant conclusions and future requirements in research and development of food products are presented.

Embryonic disc formation following post-hatching bovine embryo development in vitro.

Failures during conceptus elongation are a major cause of pregnancy losses in ungulates, exerting a relevant economic impact on farming. The developmental events occurring during this period are poorly understood, mainly because this process cannot be recapitulated in vitro. Previous studies have established an in vitro post-hatching development (PHD) system that supports bovine embryo development beyond the blastocyst stage, based on agarose gel tunnels and serum- and glucose-enriched medium. Unfortunately, under this system embryonic disc formation is not achieved and embryos show notorious signs of apoptosis and necrosis. The objective of this study has been to develop an in vitro system able to support embryonic disc formation. We first compared post-hatching development inside agarose tunnels or free-floating over an agarose-coated dish in serum- and glucose-enriched medium (PHD medium). Culture inside agarose tunnels shaped embryo morphology by physical constriction, but it restricted embryo growth and did not provide any significant advantage in terms of development of hypoblast and epiblast lineages. In contrast to PHD medium, a chemically defined and enriched medium (N2B27) supported complete hypoblast migration and epiblast survival in vitro, even in the absence of agarose coating. Cells expressing the pluripotency marker SOX2 were observed in ~56% of the embryos and ~25% developed embryonic disc-like structures formed by SOX2+ cells. In summary, here we provide a culture system that supports trophectoderm proliferation, hypoblast migration and epiblast survival after the blastocyst stage.

Data set on effect of amaranth proteins on the RAS system. In vitro, in vivo and ex vivo assays.

Data set presented in this article is related to the research paper entitled "Effect of amaranth proteins on the RAS system. In vitro, in vivo and ex vivo assays", available in Food Chemistry [1]. In this article, we evaluated the effect on systolic blood pressure of spontaneously hypertensive rats (SHR) of different samples with amaranth proteins/peptides. The effect of these samples on RAS system was evaluated using in vitro and ex vivo assays. The concentration of renin and angiotensin converting enzyme (ACE) was evaluated using two commercial ELISA kits. Renin concentration was estimated through a direct immunoassay and ACE concentration with an immunoassay based on a competitive inhibition. In addition, the ACE inhibitory activity in plasma was evaluated using a spectrophotometric assay according to [2]. Ex vivo experiments were done with thoracic aorta extracted during the surgical procedure employed to obtain blood samples according to [3]. Data presented in this article recollect a very extensive work on how can be affect the RAS system in SHR model using amaranth protein/peptides as potential antihypertensive samples. These data could be useful to design novel functional foods for hypertensive individuals.

Effect of amaranth proteins on the RAS system. In vitro, in vivo and ex vivo assays.

The aim of this work was to analyse the hypotensive effect of amaranth protein/peptides on spontaneously hypertensive rats (SHR). The mechanism of action of these peptides was studied in vivo and ex vivo. We also tested the effect of protection against gastrointestinal digestion (GID) exerted by an O:W emulsion on the integrity of the antihypertensive peptides. All samples tested produced a decrease in blood pressure (SBP). The animals treated with emulsion (GE) and emulsion + peptide (GE+VIKP) showed the most significant reduction in the SBP (42 ±â€¯2 mmHg and 35 ±â€¯2 mmHg, respectively). The results presented suggest that after GID, a variety of peptides with biological activities were released or were resistant to this process. These peptides play a role in the regulation of the SBP by acting on plasma ACE, plasma renin and the vascular system. These results support the use of amaranth protein/peptides in the elaboration of functional foods for hypertensive individuals.

Broken Rice as a Potential Functional Ingredient with Inhibitory Activity of Renin and Angiotensin-Converting Enzyme(ACE).

The aim of this work was to evaluate the ability of broken rice, an underutilized industrial by-product, as a potential functional and health promoting ingredient. With this purpose, the ability to inhibit the angiotensin converting enzyme and renin of a rice protein hydrolyzate (RPH) obtained from a high-protein variety of broken rice (var. Nutriar FCAyF) was analyzed (IC50 = 0.87 and 2.7 mg/mL, respectively). RPH was separated by gel permeation chromatography and in a second purification step by RP-HPLC. The sequence of antihypertensive peptides presented in two RP-HPLC fractions was analyzed. Peptides capable of interacting with the active sites of both enzymes were identified. In this study, we demonstrate that the hydrolysis treatment improves functional and biological properties of rice proteins. Protein preparations obtained from a by-product of rice industry, such as broken rice, are a promising ingredient with potentially good biological properties.

G protein-coupled receptor 37-like 1 modulates astrocyte glutamate transporters and neuronal NMDA receptors and is neuroprotective in ischemia.

We show that the G protein-coupled receptor GPR37-like 1 (GPR37L1) is expressed in most astrocytes and some oligodendrocyte precursors in the mouse central nervous system. This contrasts with GPR37, which is mainly in mature oligodendrocytes. Comparison of wild type and Gpr37l1-/- mice showed that loss of GPR37L1 did not affect the input resistance or resting potential of astrocytes or neurons in the hippocampus. However, GPR37L1-mediated signalling inhibited astrocyte glutamate transporters and - surprisingly, given its lack of expression in neurons - reduced neuronal NMDA receptor (NMDAR) activity during prolonged activation of the receptors as occurs in ischemia. This effect on NMDAR signalling was not mediated by a change in the release of D-serine or TNF-α, two astrocyte-derived agents known to modulate NMDAR function. After middle cerebral artery occlusion, Gpr37l1 expression was increased around the lesion. Neuronal death was increased by ∼40% in Gpr37l1-/- brain compared to wild type in an in vitro model of ischemia. Thus, GPR37L1 protects neurons during ischemia, presumably by modulating extracellular glutamate concentration and NMDAR activation.

In Vitro Modulation of Renin-Angiotensin System Enzymes by Amaranth (Amaranthus hypochondriacus) Protein-Derived Peptides: Alternative Mechanisms Different from ACE Inhibition.

Among the factors affecting the development of cardiovascular diseases, hypertension is one of the most important. Research done on amaranth proteins has demonstrated their hypotensive capacity in vivo and in vitro; nevertheless, the mechanism underlying this effect remains unclear. The aim of this study was to analyze in vitro the inhibition of peptides derived from an amaranth hydrolysate (AHH) on other RAS enzymes other than ACE. The chymase and renin activities were studied. AHH was not able to inhibit chymase activity, although a dose-response effect was found on renin activity (IC50 0.6 mg/mL). To provide an approach to the renin inhibition mechanism, we analyzed AHH renin inhibition kinetics and performed a structural characterization of the peptides involved in the effect in terms of molecular size and hydrophobicity. Results suggest that amaranth peptides exhibit renin competitive inhibition behavior. Renin inhibition potency was directly related to peptide hydrophobicity. RP-HPLC separation of AHH and subsequent analysis of the peptide sequences showed 6 peptides belonging to 11S globulin (that can be grouped into 3 families) that would be responsible for renin inhibition. These results demonstrate that Amaranthus hypochondriacus seeds are an adequate source of peptides with renin inhibitory properties that could be used in functional food formulations.

Identification of cross-reactive B-cell epitopes between Bos d 9.0101(Bos Taurus) and Gly m 5.0101 (Glycine max) by epitope mapping MALDI-TOF MS.

Exposure to cow's milk constitutes one of the most common causes of food allergy. In addition, exposure to soy proteins has become relevant in a restricted proportion of milk allergic pediatric patients treated with soy formulae as a dairy substitute, because of the cross-allergenicity described between soy and milk proteins. We have previously identified several cross-reactive allergens between milk and soy that may explain this intolerance. The purpose of the present work was to identify epitopes in the purified αS1-casein and the recombinant soy allergen Gly m 5.0101 (Gly m 5) using an α-casein-specific monoclonal antibody (1D5 mAb) through two different approaches for epitope mapping, to understand cross-reactivity between milk and soy. The 1D5 mAb was immobilized onto magnetic beads, incubated with the peptide mixture previously obtained by enzymatic digestion of the allergens, and the captured peptides were identified by MALDI-TOF MS analysis. On a second approach, the peptide mixture was resolved by RP-HPLC and immunodominant peptides were identified by dot blot with the mAb. Finally, recognized peptides were sequenced by MALDI-TOF MS. This novel MS based approach led us to identify and characterize four peptides on α-casein and three peptides on Gly m 5 with a common core motif. Information obtained from these cross-reactive epitopes allows us to gain valuable insight into the molecular mechanisms of cross-reactivity, to further develop new and more effective vaccines for food allergy.

Two years of surveillance of influenza a virus infection in a swine herd. Results of virological, serological and pathological studies.

Swine farms provide a dynamic environment for the evolution of influenza A viruses (IAVs). The present report shows the results of a surveillance effort of IAV infection in one commercial swine farm in Argentina. Two cross-sectional serological and virological studies (n=480) were carried out in 2011 and 2012. Virus shedding was detected in nasal samples from pigs from ages 7, 21 and 42-days old. More than 90% of sows and gilts but less than 40% of 21-days old piglets had antibodies against IAV. In addition, IAV was detected in 8/17 nasal swabs and 10/15 lung samples taken from necropsied pigs. A subset of these samples was further processed for virus isolation resulting in 6 viruses of the H1N2 subtype (δ2 cluster). Pathological studies revealed an association between suppurative bronchopneumonia and necrotizing bronchiolitis with IAV positive samples. Statistical analyses showed that the degree of lesions in bronchi, bronchiole, and alveoli was higher in lungs positive to IAV. The results of this study depict the relevance of continuing long-term active surveillance of IAV in swine populations to establish IAV evolution relevant to swine and humans.

Sox5 controls dorsal progenitor and interneuron specification in the spinal cord.

The basic organization of somatosensory circuits in the spinal cord is already setup during the initial patterning of the dorsal neural tube. Extrinsic signals, such as Wnt and TGF-ß pathways, activate combinatorial codes of transcription factors that are responsible for generating a pattern of discrete domains of dorsal progenitors (dp). These progenitors will give rise to distinct dorsal interneurons (dI). The Wnt/ ßcatenin signaling pathway controls specification of dp/dI1-3 progenitors and interneurons. According to the current model in the field, Wnt/ßcatenin activity seems to act in a graded fashion in the spinal cord, as different relative levels determine the identity of adjacent progenitors. However, it is not clear how this activity gradient is controlled and how the identities of dI1-3 are differentially regulated by Wnt signalling. We have determined that two SoxD transcription factors, Sox5 and Sox6, are expressed in restricted domains of dorsal progenitors in the neural tube. Using gain- and loss-of function approaches in chicken embryos, we have established that Sox5 controls cell fate specification of dp2 and dp3 progenitors and, as a result, controls the correct number of the corresponding dorsal interneurons (dI2 and dI3). Furthermore, Sox5 exerts its function by restricting dorsally Wnt signaling activity via direct transcriptional induction of the negative Wnt pathway regulator Axin2. By that way, Sox5 acts as a Wnt pathway modulator that contributes to sharpen the dorsal gradient of Wnt/ßcatenin activity to control the distinction of two functionally distinct types of interneurons, dI2 and dI3 involved in the somatosensory relay.

Physicochemical, functional and angiotensin converting enzyme inhibitory properties of amaranth (Amaranthus hypochondriacus) 7S globulin.

BACKGROUND: Amaranth 7S globulin is a minor globulin component and its impact on the properties of an amaranth protein ingredient depends on its proportion in the variety of amaranth being considered. Some physicochemical, functional and angiotesin I-converting enzyme (ACE) inhibitory properties of amaranth vicilin were studied in this work and compared with the 11S globulin. RESULTS: Fluorescence spectroscopy results indicated that 7S globulin tryptophans were more exposed to the solvent and, by calorimetry, the 7S globulin denaturation temperature (T(d) ) was found lower than the 11S globulin T(d) , suggesting a more flexible structure. The 7S globulin surface hydrophobicity was higher than that of the 11S globulin, which is in agreement with the better emulsifying properties of the 7S globulin. The solubility in neutral buffer of the 7S globulin (851 ± 25 g kg(-1) ) was also higher than that of the 11S globulin (195 ± 6 g kg(-1) ). Bioinformatic analyses showed the presence of ACE inhibitory peptides encrypted in 7S tryptic sequences and peptides released after in vitro gastrointestinal digestion showed a high ACE-inhibitory capacity (IC(50) = 0.17 g L(-1) ), similar to that of 11S globulin peptides. CONCLUSION: Compared with the 11S globulin, the 7S globulin presents similar ACE inhibitory activity and some functional advantages, better solubility and emulsifying activity, which suits some food requirements. The functional behavior has been related with the structural properties.

FGF and retinoic acid activity gradients control the timing of neural crest cell emigration in the trunk.

Coordination between functionally related adjacent tissues is essential during development. For example, formation of trunk neural crest cells (NCCs) is highly influenced by the adjacent mesoderm, but the molecular mechanism involved is not well understood. As part of this mechanism, fibroblast growth factor (FGF) and retinoic acid (RA) mesodermal gradients control the onset of neurogenesis in the extending neural tube. In this paper, using gain- and loss-of-function experiments, we show that caudal FGF signaling prevents premature specification of NCCs and, consequently, premature epithelial-mesenchymal transition (EMT) to allow cell emigration. In contrast, rostrally generated RA promotes EMT of NCCs at somitic levels. Furthermore, we show that FGF and RA signaling control EMT in part through the modulation of elements of the bone morphogenetic protein and Wnt signaling pathways. These data establish a clear role for opposition of FGF and RA signaling in control of the timing of NCC EMT and emigration and, consequently, coordination of the development of the central and peripheral nervous system during vertebrate trunk elongation.

Amaranth (Amaranthus hypochondriacus) vicilin subunit structure.

The 7S-globulin fraction is a minor component of the amaranth storage proteins. The present work provides new information about this protein. The amaranth 7S-globulin or vicilin presented a sedimentation coefficient of 8.6 ± 0.6 S and was composed of main subunits of 66, 52, 38, and 16 kDa. On the basis of mass spectrometry (MS) analysis of tryptic fragments, the 52, 38, and 16 kDa subunits presented sequence homology with sesame vicilin, whereas the 66 kDa subunit showed sequence similarity with a putative vicilin. Several characteristics of the 66 kDa subunit were similar to members of the convicilin family. Results support the hypothesis that the 7S-globulin molecules are composed of subunits coming from at least two gene families with primary products of 66 and 52 kDa, respectively. According to the present information, amaranth vicilin may be classified into the vicilin group that includes pea, broad bean, and sesame vicilins, among others.

SOX5 controls cell cycle progression in neural progenitors by interfering with the WNT-beta-catenin pathway.

Genes of the SOX family of high-mobility group transcription factors are essential during nervous system development. In this study, we show that SOX5 is expressed by neural progenitors in the chick spinal cord and is turned off as differentiation proceeds. The overexpression of SOX5 in neural progenitors causes premature cell cycle exit and prevents terminal differentiation. Conversely, knocking down SOX5 protein extends the proliferative period of neural progenitors and causes marked cell death in a dorsal interneuron (dI3) population. Furthermore, SOX5 reduces WNT-beta-catenin signalling, thereby triggering the expression of the negative regulator of the pathway axin2. We propose that SOX5 regulates the timing of cell cycle exit by opposing WNT-beta-catenin activity on cell cycle progression.

Globulin-p and 11S-globulin from amaranthus Hypochondriacus: are two isoforms of the 11S-globulin.

Amaranth is an ancient crop with a high content of good quality proteins. Globulins are some of the most abundant storage proteins of amaranth grain. They contain two fractions distinguishable according to their different solubility: the salt-soluble 7S and 11S-globulins and the globulin-p soluble in mild-alkaline, low-ionic-strength solutions. As part of the amaranth proteins characterization, in this work we investigated the structural characteristics responsible for the different physicochemical properties of these globulins. We studied certain conformational parameters of the purified aggregates (AMGp) and individual molecules (IMGp) of globulin-p and of the partially purified globulin (ppGb) and compared the AMGp polypeptide sequences with the sequence of the 11S-globulin propolypeptide from Amaranthus (gi|122726601). The results indicated that the AMGp aggregates are responsible for the different solubility of globulin-p. Subtle conformational differences as determined by fluorescence spectroscopy and urea sensitivity were found between the molecules studied: The AMGp showed some surface differences from the IMGp and the ppGb; the AMGp also had a lower affinity for the hydrophobic fluorescent probe 1,8-aniline-naphthalene-sulfonate and a higher ionic charge than the ppGb and the IMGp, characteristics that might cause their lower solubility. In addition, we have demonstrated differences between the AMGp polypeptide sequences and that reported for amaranth 11S-globulin. These differences suggest that the globulin-p and 11S-globulin are two 11S-globulin isoforms comprised of polypeptides coming from different legumin-gene subfamilies.