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The α-Proteobacteria belonging to Bradyrhizobium genus are microorganisms of extreme slow growth. Despite their extended use as inoculants in soybean production, their physiology remains poorly characterized. In this work, we produced quantitative data on four different isolates: B. diazoefficens USDA110, B. diazoefficiens USDA122, B. japonicum E109 and B. japonicum USDA6 which are representative of specific genomic profiles. Notably, we found conserved physiological traits conserved in all the studied isolates: (i) the lag and initial exponential growth phases display cell aggregation; (ii) the increase in specific nutrient concentration such as yeast extract and gluconate hinders growth; (iii) cell size does not correlate with culture age; and (iv) cell cycle presents polar growth. Meanwhile, fitness, cell size and in vitro growth widely vary across isolates correlating to ribosomal RNA operon number. In summary, this study provides novel empirical data that enriches the comprehension of the Bradyrhizobium (slow) growth dynamics and cell cycle.
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Bradyrhizobium , Bradyrhizobium/genética , Bradyrhizobium/metabolismo , Glycine max , Fenómenos Fisiológicos Celulares , Fenotipo , SimbiosisRESUMEN
Rifampicin (RIF) is an antibiotic used to treat tuberculosis and leprosy. Even though RIF is a market-available drug, it has a low aqueous solubility, hindering its bioavailability. Among the strategies for bioavailability improvement of poorly soluble drugs, coamorphous systems have been revealed as an alternative in the increase of the aqueous solubility of drug systems and at the same time also increasing the amorphous state stability and dissolution rate when compared with the neat drug. In this work, a new coamorphous form from RIF and tromethamine (TRIS) was synthesized by slow evaporation. Structural, electronic, and thermodynamic properties and solvation effects, as well as drug-coformer intermolecular interactions, were studied through density functional theory (DFT) calculations. Powder X-ray diffraction (PXRD) data allowed us to verify the formation of a new coamorphous. In addition, the DFT study indicates a possible intermolecular interaction by hydrogen bonds between the available amino and carbonyl groups of RIF and the hydroxyl and amino groups of TRIS. The theoretical spectra obtained are in good agreement with the experimental data, suggesting the main interactions occurring in the formation of the coamorphous system. PXRD was used to study the physical stability of the coamorphous system under accelerated ICH conditions (40 °C and 75% RH), indicating that the material remained in an amorphous state up to 180 days. The thermogravimetry result of this material showed a good thermal stability up to 153 °C, and differential scanning calorimetry showed that the glass temperature (Tg) was at 70.0 °C. Solubility studies demonstrated an increase in the solubility of RIF by 5.5-fold when compared with its crystalline counterpart. Therefore, this new material presents critical parameters that can be considered in the development of new coamorphous formulations.
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Rifampin , Trometamina , Composición de Medicamentos , Solubilidad , Agua , Modelos Teóricos , Estabilidad de Medicamentos , Rastreo Diferencial de Calorimetría , Difracción de Rayos XRESUMEN
Autoimmune inflammatory diseases, such as rheumatoid arthritis (RA) and ulcerative colitis, are associated with an uncontrolled production of cytokines leading to the pronounced inflammatory response of these disorders. Their therapy is currently focused on the inhibition of cytokine receptors, such as the Janus kinase (JAK) protein family. Tofacitinib and peficitinib are JAK inhibitors that have been recently approved to treat rheumatoid arthritis. In this study, an in-depth analysis was carried out through quantum biochemistry to understand the interactions involved in the complexes formed by JAK1 and tofacitinib or peficitinib. Computational analyses provided new insights into the binding mechanisms between tofacitinib or peficitinib and JAK1. The essential amino acid residues that support the complex are also identified and reported. Additionally, we report new interactions, such as van der Waals; hydrogen bonds; and alkyl, pi-alkyl, and pi-sulfur forces, that stabilize the complexes. The computational results revealed that peficitinib presents a similar affinity to JAK1 compared to tofacitinib based on their interaction energies.
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Adamantano/análogos & derivados , Janus Quinasa 1 , Niacinamida , Niacinamida/análogos & derivados , Piperidinas , Pirimidinas , Pirimidinas/química , Pirimidinas/farmacología , Piperidinas/química , Piperidinas/farmacología , Piperidinas/uso terapéutico , Niacinamida/química , Janus Quinasa 1/antagonistas & inhibidores , Janus Quinasa 1/metabolismo , Janus Quinasa 1/química , Humanos , Teoría Cuántica , Enfermedades Autoinmunes/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Enlace de Hidrógeno , Inhibidores de las Cinasas Janus/química , Inhibidores de las Cinasas Janus/uso terapéutico , Inhibidores de las Cinasas Janus/farmacología , Adamantano/química , Pirroles/química , Pirroles/farmacología , Simulación del Acoplamiento MolecularRESUMEN
The present work reports the inhibitory effect of amides derived from gallic acid (gallamides) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro), along with cytotoxicity evaluation and molecular docking studies. In addition to gallamides, other relevant compounds were also synthesized and evaluated against Mpro, making a total of 25 compounds. Eight compounds presented solubility issues during the inhibitory assay and one showed no inhibitory activity. Compounds 3a, 3b, and 3f showed the highest enzymatic inhibition with IC50 = 0.26 ± 0.19 µM, 0.80 ± 0.38 µM, and 2.87 ± 1.17 µM, respectively. Selenogallamide 6a exhibited IC50 values of 5.42 ± 2.89 µM and a comparison with its nonselenylated congener 3c shows that the insertion of the chalcogen moiety improved the inhibitory capacity of the compound by approximately 10 times. Regarding the cellular toxicity in THP-1 and Vero cells, compounds 3e and 3g, showed moderate cytotoxicity in Vero cells, while for THP-1 both were nontoxic, with CC50 > 150 µM. Derivative 3d showed moderate cytotoxicity against both cell lines, whereas 6d was moderatly toxic to THP-1. Other compounds analyzed do not induce substantial cellular toxicity at the concentrations tested. The molecular docking results for compounds 3a, 3b, and 3f show that hydrogen bonding interactions involving the hydroxyl groups (OH) of the gallate moiety are relevant, as well as the carbonyl group.
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We introduce a new class of zero-or-one inflated power logit (IPL) regression models, which serve as a versatile tool for analyzing bounded continuous data with observations at a boundary. These models are applied to explore the effects of climate changes on the distribution of tropical tuna within the North Atlantic Ocean. Our findings suggest that our modeling approach is adequate and capable of handling the outliers in the data. It exhibited superior performance compared to rival models in both diagnostic analysis and regarding the inference robustness. We offer a user-friendly method for fitting IPL regression models in practical applications.
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Clima Tropical , Atún , Animales , Modelos Logísticos , Océano Atlántico , Biometría/métodosRESUMEN
The objective of this study was to evaluate the effect of increasing levels of spineless cactus (SC) [Nopalea cochenillifera (L.) Salm Dyck] on nutrient intake, ingestive behaviour, and performance of lambs in a feedlot. Thirty-two male (non-castrated) Santa Inês lambs with a mean initial body weight (BW) of 20.4 ± 2.60 kg were distributed across four levels of spineless cactus: zero, 24, 52, and 75% of total diet dry matter (DM). Over 56 days, the animals had their intake and performance monitored. The inclusion of SC influenced (p<0.05) in a quadratic way the dry matter intake and total digestible nutrients, but linearly decreased (p<0.05) the neutral detergent fiber intake. Drinking water intake decreased linearly (p<0.05) with the inclusion of SC in the diet. The inclusion of SC influenced (p<0.05) in a quadratic way the digestibility of organic matter in the diet. The increase in the level of SC in the diet increased linearly (p<0.05) the feeding and rumination efficiencies of the lambs. The maximum daily gain of 0.237 kg/day was achieved with 44% SC in the diet. It is recommended to include up to 40% of spineless cactus in the diet of lambs.
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Cactaceae , Ovinos , Animales , Masculino , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Oveja Doméstica , Ingestión de Alimentos , Dieta/veterinaria , Digestión , Fibras de la DietaRESUMEN
SARS-CoV-2 main protease (Mpro ) plays an essential role in proteolysis cleavage that promotes coronavirus replication. Thus, attenuating the activity of this enzyme represents a strategy to develop antiviral agents. We report inhibitory effects against Mpro of 40 synthetic chalcones, and cytotoxicity activities, hemolysis, and in silico interactions of active compounds. Seven of them bearing a (E)-3-(furan-2-yl)-1-arylprop-2-en-1-one skeleton (10, 28, and 35-39) showed enzyme inhibition with IC50 ranging from 13.76 and 36.13â µM. Except for 35 and 36, other active compounds were not cytotoxic up to 150â µM against THP-1 and Vero cell lines. Compounds 10, and 35-39 showed no hemolysis while 28 was weakly hemotoxic at 150â µM. Moreover, molecular docking showed interactions between compound 10 and Mpro (PDBID 5RG2 and 5RG3) with proximity to cys145 and His41, suggesting a covalent binding. Products of the reaction between chalcones and cyclohexanethiol indicated that this binding could be a Michael addition type.
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COVID-19 , Chalconas , Humanos , SARS-CoV-2 , Simulación del Acoplamiento Molecular , Chalconas/farmacología , Chalconas/química , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/química , Antivirales/farmacología , Antivirales/química , Simulación de Dinámica MolecularRESUMEN
COVID-19 has caused many deaths since the first outbreak in 2019. The burden on healthcare systems around the world has been reduced by the success of vaccines. However, population adherence and the occurrence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are still challenging tasks to be affronted. In addition, the newly approved drug presents some limitations in terms of side effects and drug interference, highlighting the importance of searching for new antiviral agents against SARS-CoV-2. The SARS-CoV-2 main protease (Mpr o ) represents a versatile target to search for new drug candidates due to its essential role in proteolytic activities responsible for the virus replication. In this work, a series of 190 compounds, composed of 27 natural ones and 163 synthetic compounds, were screened in vitro for their inhibitory effects against SARS-CoV-2 Mpro . Twenty-five compounds inhibited Mpro with inhibitory constant values (Ki ) between 23.2 and 241 µM. Among them, a thiosemicarbazone derivative was the most active compound. Molecular docking studies using Protein Data Bank ID 5RG1, 5RG2, and 5RG3 crystal structures of Mpro revealed important interactions identified as hydrophobic, hydrogen bonding and steric interactions with amino acid residues in the active site cavity. Overall, our findings indicate the described thiosemicarbazones as good candidates to be further explored to develop antiviral leads against SARS-CoV-2. Moreover, the studies showed the importance of careful evaluation of test results to detect and exclude false-positive findings.
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COVID-19 , SARS-CoV-2 , Humanos , Simulación del Acoplamiento Molecular , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/química , Relación Estructura-Actividad , Antivirales/farmacología , Antivirales/química , Simulación de Dinámica MolecularRESUMEN
BACKGROUND: Fractures around the elbow are common in children. Their management remains challenging. Inadequate treatment often leads to malunion, causing growth disturbance or avascular necrosis. This can develop into cubital axis deformities. This study evaluated our modified supracondylar dome osteotomy technique for acute correction of posttraumatic cubital axis deformities in adolescent patients. METHODS: Eighteen cases of posttraumatic cubital axis deformity that underwent acute correction through supracondylar dome osteotomy in our department between 2012 and 2019 were retrospectively evaluated. The radiologic results were measured through the carrying angle. The clinical functional outcomes were assessed using the Mayo Elbow Performance Index. RESULTS: No neurovascular injuries occurred and there was no notable loss of muscular strength or functional deficiencies in any of the patients. Symmetrical cubital axes were achieved in all cases. All cases were consolidated in a timely matter and no malunion was observed upon consolidation. Besides 1 case of hardware damage caused by a severe fall due to heavy alcohol intoxication, there was no correction loss, no secondary displacement, and no implant-related discomfort. None of the patients were left with a limited range of motion or reduced weight-bearing capacity. An excellent level of elbow functionality was achieved in all cases, with an average Mayo Elbow Performance Index of 97.8. CONCLUSIONS: The supracondylar dome osteotomy technique showed promising results in both radiologic outcomes and clinical performance, with a low complication rate. The dome-shaped osteotomy allows simultaneous multiplanar correction of not only varus or valgus deformities but also additional extension or flexion deformities. This technique also enables translation of the distal fragment in the frontal plane, which contributes to a more balanced anatomic geometry of the distal humerus. We consider the posterior triceps-splitting approach to be a safe technique that preserves muscle strength and improves the cosmetic appearance of the surgical scar. We recommend a cast-free plate fixation to allow early movement after surgery. We believe any residual deformities that present 18 months after the initial trauma should be addressed through surgical correction before clinical symptoms become apparent to avoid the chronic manifestation of functional deficiencies. LEVEL OF EVIDENCE: Level IV, therapeutic study, case series.
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Articulación del Codo , Fracturas del Húmero , Deformidades Adquiridas de la Articulación , Niño , Humanos , Adolescente , Deformidades Adquiridas de la Articulación/cirugía , Fracturas del Húmero/cirugía , Fracturas del Húmero/complicaciones , Estudios Retrospectivos , Osteotomía/métodos , Articulación del Codo/cirugía , Rango del Movimiento Articular/fisiología , Resultado del TratamientoRESUMEN
The growing use of multimodal high-resolution volumetric data in pre-clinical studies leads to challenges related to the management and handling of the large amount of these datasets. Contrarily to the clinical context, currently there are no standard guidelines to regulate the use of image compression in pre-clinical contexts as a potential alleviation of this problem. In this work, the authors study the application of lossy image coding to compress high-resolution volumetric biomedical data. The impact of compression on the metrics and interpretation of volumetric data was quantified for a correlated multimodal imaging study to characterize murine tumor vasculature, using volumetric high-resolution episcopic microscopy (HREM), micro-computed tomography (µCT), and micro-magnetic resonance imaging (µMRI). The effects of compression were assessed by measuring task-specific performances of several biomedical experts who interpreted and labeled multiple data volumes compressed at different degrees. We defined trade-offs between data volume reduction and preservation of visual information, which ensured the preservation of relevant vasculature morphology at maximum compression efficiency across scales. Using the Jaccard Index (JI) and the average Hausdorff Distance (HD) after vasculature segmentation, we could demonstrate that, in this study, compression that yields to a 256-fold reduction of the data size allowed to keep the error induced by compression below the inter-observer variability, with minimal impact on the assessment of the tumor vasculature across scales.
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Compresión de Datos , Neoplasias , Humanos , Animales , Ratones , Compresión de Datos/métodos , Microtomografía por Rayos X , Imagen por Resonancia Magnética , Imagen Multimodal , Procesamiento de Imagen Asistido por Computador/métodosRESUMEN
In a randomized crossover trial, we examined the effects of interrupting sedentary behavior on glycemic control in trained older adults, before and after 2 weeks of detraining. Fourteen participants (65-90 years old) completed two 7-hr conditions before and after 2 weeks of detraining: (a) uninterrupted sitting (SIT) and (b) sitting plus 2 min of moderate-intensity activity every 30 min (INT). Both before and after detraining, no differences were observed for 7-hr glucose area under the curve (7 hr AUC) and mean glucose between sitting plus 2 min of moderate-intensity activity and uninterrupted sitting conditions. After detraining and for the SIT condition, higher values of 7-hr AUC (p = .014) and mean glucose (p = .015) were observed, indicating worsened glycemic control. No changes were observed in INT condition between both time points. Frequent interruptions in sedentary behavior had no effect on glycemic control, prior to or after detraining. Even so, older adults experiencing a short-term detraining period should avoid prolonged bouts of sedentary behavior that may jeopardize their glycemic control.
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Glucemia , Conducta Sedentaria , Humanos , Anciano , Anciano de 80 o más Años , Estudios Cruzados , Periodo Posprandial , GlucosaRESUMEN
In testicular germ cell tumor type II (TGCT), a seminoma subtype expresses an induced pluripotent stem cell (iPSC) panel with four upregulated genes, OCT4/POU5F1, SOX17, KLF4, and MYC, and embryonal carcinoma (EC) has four upregulated genes, OCT4/POU5F1, SOX2, LIN28, and NANOG. The EC panel can reprogram cells into iPSC, and both iPSC and EC can differentiate into teratoma. This review summarizes the literature on epigenetic regulation of the genes. Epigenetic mechanisms, such as methylations of cytosines on the DNA string and methylations and acetylations of histone 3 lysines, regulate expression of these driver genes between the TGCT subtypes. In TGCT, the driver genes contribute to well-known clinical characteristics and the driver genes are also important for aggressive subtypes of many other malignancies. In conclusion, epigenetic regulation of the driver genes are important for TGCT and for oncology in general.
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Carcinoma Embrionario , Neoplasias de Células Germinales y Embrionarias , Neoplasias Testiculares , Masculino , Humanos , Epigénesis Genética , Neoplasias Testiculares/genética , Neoplasias de Células Germinales y Embrionarias/genética , Carcinoma Embrionario/genética , Carcinogénesis/genética , Transformación Celular Neoplásica/genéticaRESUMEN
Bird nests on transmission lines can cause electrical faults which reduce service reliability. To address this problem, since the mid-90s, the Portuguese Transmission System Operator (TSO) has undertaken management actions to discourage white storks Ciconia ciconia from nesting in hazardous locations of the pylons. Here, we compiled and analyzed an 18-year series of data on electrical faults, TSO management actions to tackle these, and stork nests on transmission pylons in Portugal to: (a) determine the relative importance of bird-related faults over the total number of faults; (b) describe variations in bird-related faults across time (season of the year and time of the day); (c) describe spatial variations in bird-related faults and their association with the occurrence of white stork nests on pylons; and (d) analyze the trends, over the years, of the number of white stork nests on pylons, the TSO management actions and their effectiveness in reducing bird-related fault rates. Overall, birds accounted, on average, for 25.3% of the electrical faults in the transmission network, with the vast majority being attributed to white storks. The seasonal pattern of bird-related faults showed higher rates in April and in October-November. Faults occurred more often during the night period, when storks spend more time on the pylons. We found a positive spatial relationship between the electrical fault rate and the proportion of pylons with stork nests (and the correlated number of nests per 100 km of line). There was, however, considerable variation in the fault rates not explained by the stork nest variables, particularly during the non-breeding season. The TSO management actions (namely removal/translocation of nests in hazardous locations of the pylons, installation of anti-perching devices and provision of alternative nesting platforms) significantly reduced, as a whole, the annual number of bird-related faults between 2001 and 2018, despite the three-fold increase in the number of white stork nests on transmission pylons. A deeper understanding of how white storks use the transmission pylons outside the breeding season is needed, so that targeted management actions can be taken to reduce the remaining bird-related fault rates to residual levels.
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Aves , Animales , Reproducibilidad de los Resultados , Estaciones del Año , PortugalRESUMEN
OBJECTIVE: We present a novel digital workflow to provide presurgical infant orthopedic (PSIO) treatment for a patient with a unilateral cleft lip/palate utilizing nasoalveolar molding (NAM) and a custom postsurgical nasal stent. SETTING: Within the US military healthcare system, the Joint Base San Antonio Craniofacial Anomalies Team utilizes dental scanners, predictive 3D modeling software, and 3D printing technology in a digital workflow for NAM appliance fabrication. WORKFLOW: Soft tissue facial scanning, peri-oral scanning, and dental putty impressions are used to facilitate fabrication and measure outcomes. Digital modeling software and 3D resin printing are utilized to manufacture the prescribed devices. MAIN OUTCOME MEASURES AND RESULTS: Extra-oral facial scans and intra-oral impressions are compared between 3 timepoints: pre-treatment, posttreatment with NAM, and postsurgical treatment. CONCLUSIONS: The ability to share workflows, establish outcome standards, and streamline patient care will continue to advance best practices in digital PSIO.
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Labio Leporino , Fisura del Paladar , Lactante , Humanos , Labio Leporino/cirugía , Fisura del Paladar/cirugía , Nariz/cirugía , Flujo de Trabajo , Modelado Nasoalveolar , StentsRESUMEN
Endothermy, understood as the maintenance of continuous and high body temperatures owing to the combination of metabolic heat production and an insulative cover, is severely challenged in small endotherms inhabiting cold environments. As a response, social clustering combined with nest use (=communal nesting) is a common strategy for heat conservation. To quantify the actual amount of energy that is saved by this strategy, we studied the social marsupial Dromiciops gliroides (monito del monte), an endemic species of the cold forests of southern South America. It is hypothesized that sociability in this marsupial was driven by cold conditions, but evidence supporting this hypothesis is unclear. Here, we used taxidermic models ('mannequins') to experimentally test the energetic benefits of clustering combined with nest use. To do this, we fitted and compared cooling curves of solitary and grouped mannequins, within and outside of a nest, at the typical winter ambient temperatures of their habitat (5°C). We found that the strategy that minimized euthermic cost of maintenance was the combination of nest use and clustering, thus supporting communal nesting as a social adaptation to cope with the cold. Considering the basal metabolic rate of monitos, our estimates suggest that the savings represents almost half of energy consumption per day (in resting conditions). This study shows how simple biophysical models could help to evaluate bioenergetic hypotheses for social behavior in cold-adapted endotherms.
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Marsupiales , Animales , Marsupiales/fisiología , Calor , Metabolismo Basal , Metabolismo Energético/fisiología , TermogénesisRESUMEN
This review provides an update to the last mini-review with the same title pertaining to recent developments in bioleaching and biooxidation published in 2013 (Brierley and Brierley). In the intervening almost 10 years, microbial processes for sulfide minerals have seen increased acceptance and ongoing but also declining commercial application in copper, gold, nickel and cobalt production. These processes have been applied to heap and tank leaching, nowadays termed biomining, but increasing concerns about the social acceptance of mining has also seen the re-emergence of in situ leaching and quest for broader applicability beyond uranium and copper. Besides metal sulfide oxidation, mineral dissolution via reductive microbial activities has seen experimental application to laterite minerals. And as resources decline or costs for their exploitation rise, mine waste rock and tailings have become more attractive to consider as easily accessible resources. As an advantage, they have already been removed from the ground and in some cases contain ore grades exceeding that of those currently being mined. These factors promote concepts of circular economy and efficient use and valorization of waste materials. KEY POINTS: ⢠Bioleaching of copper sulfide ore deposits is producing less copper today ⢠Biooxidation of refractory gold ores is producing more gold than in the past ⢠Available data suggest bioleaching and biooxidation processes reduce carbon emissions.
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Cobre , Minería , Oro , Minerales , SulfurosRESUMEN
Crude glycerin is a byproduct of the biodiesel industry and has been widely used in ruminant diets as a source of energy, usually in place of corn, primarily during periods of drought in tropical regions. The objective of this study was to evaluate the effect of including levels of the crude glycerin of low purity (0, 6, 12 and 18%) replacing corn in the diets of goats on the carcass characteristics, tissue composition, meat cuts yield and physicochemical parameters of meat. Forty males castrated without defined racial pattern goats an initial average weight of 19.70 ± 2.30 kg were slaughtered after 86 days. Diets content 0 and 6% crude glycerin promoted similar responses to the analyzed variables, except for pH and breast weight. No differences were observed to total digestible nutrients, slaughter body weight, commercial cut yield leg tissue composition and physicochemical parameters of meat. Crude glycerin can be included up to 12% without losses on carcass weight and meat cuts, leg composition, and meat quality. The inclusion of crude glycerin containing 63.06% glycerol and 45.57% lipids could be effective in partial replacement of corn in diets for confined goats in tropical areas.
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Glicerol , Cabras , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Masculino , Carne/análisisRESUMEN
The soma, dendrites and axon of neurons may display calcium-dependent release of transmitters and peptides. Such release is named extrasynaptic for occurring in absence of synaptic structures. This review describes the cooperative actions of three calcium sources on somatic exocytosis. Emphasis is given to the somatic release of serotonin by the classical leech Retzius neuron, which has allowed detailed studies on the fine steps from excitation to exocytosis. Trains of action potentials induce transmembrane calcium entry through L-type channels. For action potential frequencies above 5 Hz, summation of calcium transients on individual action potentials activates the second calcium source: ryanodine receptors produce calcium-induced calcium release. The resulting calcium tsunami activates mitochondrial ATP synthesis to fuel transport of vesicles to the plasma membrane. Serotonin that is released maintains a large-scale exocytosis by activating the third calcium source: serotonin autoreceptors coupled to phospholipase C promote IP3 production. Activated IP3 receptors in peripheral endoplasmic reticulum release calcium that promotes vesicle fusion. The Swiss-clock workings of the machinery for somatic exocytosis has a striking disadvantage. The essential calcium-releasing endoplasmic reticulum near the plasma membrane hinders the vesicle transport, drastically reducing the thermodynamic efficiency of the ATP expenses and elevating the energy cost of release.
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Señalización del Calcio , Calcio/metabolismo , Neuronas/metabolismo , Serotonina/metabolismo , Potenciales de Acción , Animales , Exocitosis , Regulación de la Expresión Génica , Humanos , Mitocondrias/metabolismo , TermodinámicaRESUMEN
BACKGROUND: While leeches in the genus Hirudo have long been models for neurobiology, the molecular underpinnings of nervous system structure and function in this group remain largely unknown. To begin to bridge this gap, we performed RNASeq on pools of identified neurons of the central nervous system (CNS): sensory T (touch), P (pressure) and N (nociception) neurons; neurosecretory Retzius cells; and ganglia from which these four cell types had been removed. RESULTS: Bioinformatic analyses identified 3565 putative genes whose expression differed significantly among the samples. These genes clustered into 9 groups which could be associated with one or more of the identified cell types. We verified predicted expression patterns through in situ hybridization on whole CNS ganglia, and found that orthologous genes were for the most part similarly expressed in a divergent leech genus, suggesting evolutionarily conserved roles for these genes. Transcriptional profiling allowed us to identify candidate phenotype-defining genes from expanded gene families. Thus, we identified one of eight hyperpolarization-activated cyclic-nucleotide gated (HCN) channels as a candidate for mediating the prominent sag current in P neurons, and found that one of five inositol triphosphate receptors (IP3Rs), representing a sub-family of IP3Rs absent from vertebrate genomes, is expressed with high specificity in T cells. We also identified one of two piezo genes, two of ~ 65 deg/enac genes, and one of at least 16 transient receptor potential (trp) genes as prime candidates for involvement in sensory transduction in the three distinct classes of leech mechanosensory neurons. CONCLUSIONS: Our study defines distinct transcriptional profiles for four different neuronal types within the leech CNS, in addition to providing a second ganglionic transcriptome for the species. From these data we identified five gene families that may facilitate the sensory capabilities of these neurons, thus laying the basis for future work leveraging the strengths of the leech system to investigate the molecular processes underlying and linking mechanosensation, cell type specification, and behavior.
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Sanguijuelas , Animales , Sistema Nervioso Central , Hibridación in Situ , Sanguijuelas/genética , NeuronasRESUMEN
Disseminated cutaneous leishmaniasis (DCL) is an uncommon form of Leishmania braziliensis infection. It remains unknown why some people develop this clinical condition. We describe 14 DCL patients in Northeast Brazil during 2015-2018. These patients regularly drank large amounts of alcohol, possibly increasing their risk for DCL.