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1.
J Dairy Sci ; 107(7): 4495-4508, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38369113

RESUMEN

This study was conducted to evaluate the effects of live or autolyzed yeast supplementation on dairy cow performance and ruminal fermentation. Two experiments were conducted to evaluate performance, feed sorting, total-tract apparent digestibility of nutrients, purine derivatives excretion, N utilization, ruminal fermentation, and the abundance of specific bacterial groups in the rumen. In experiment 1, 39 Holstein cows (171 ± 40 DIM and 32.6 ± 5.4 kg/d milk yield) were blocked according to parity, DIM, and milk yield and randomly assigned to the following treatments: control (CON); autolyzed yeast fed at 0.625 g/kg DM (AY; Levabon, DSM-Firmenich); or live yeast fed at 0.125 g/kg DM (LY; Vistacell, AB Vista). Cows were submitted to a 2-wk adaptation period followed by a 9-wk trial. In experiment 2, 8 ruminal cannulated Holstein cows (28.4 ± 4.0 kg/d milk yield and 216 ± 30 DIM), of which 4 were multiparous and 4 were primiparous, were blocked according to parity and enrolled into a 4 × 4 Latin square experiment with 21-d periods (the last 7 d for sampling). Cows within blocks were randomly assigned to treatment sequences: control (CON), LY (using the same product and dietary concentration as described in experiment 1), AY, or autolyzed yeast fed at 0.834 g/kg DM (AY2). In experiments 1 and 2, nutrient intake and total-tract apparent digestibility were not affected by treatments. Sorting for long feed particles (>19 mm) tended to be greater in cows fed yeast supplements than CON in experiment 1. Efficiency of N conversion into milk N was increased when feeding yeast supplements in experiment 1, and 3.5% FCM yield tended to be greater in cows fed yeast supplements than CON. Feed efficiency was increased when yeast supplements were fed to cows in relation to CON in experiment 1. In experiment 2, yield of FCM and fat were greater in cows fed yeast supplements compared with CON. Uric acid concentration and output in urine were increased when feeding yeast supplements when compared with CON. Neither ruminal pH nor total VFA were influenced by treatments. The current study did not reveal treatment differences in ruminal abundance of Anaerovibrio lipolytica, the genus Butyrivibrio, Fibrobacter succinogenes, Butyrivibrio proteoclasticus, or Streptococcus bovis. Yeast supplementation can increase feed efficiency without affecting nutrient intake and digestibility, ruminal VFA concentration, or ruminal abundance of specific bacterial groups. Supplementing live or autolyzed yeast, regardless of the dose, resulted in similar performance.


Asunto(s)
Alimentación Animal , Dieta , Suplementos Dietéticos , Digestión , Fermentación , Lactancia , Leche , Rumen , Animales , Bovinos , Femenino , Rumen/metabolismo , Dieta/veterinaria , Leche/química , Leche/metabolismo , Levaduras , Nutrientes/metabolismo
2.
J Dairy Sci ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38851567

RESUMEN

The aim of this study was to evaluate the effects of different anti-mycotoxin feed additives on the concentration of mycotoxins in milk, urine, and blood plasma of dairy cows fed artificially multi-mycotoxin-contaminated diets. Secondarily, performance, total-tract apparent digestibility of nutrients, and blood parameters were evaluated. Twelve multiparous cows (165 ± 45 d in milk, 557 ± 49 kg body weight, and 32.1 ± 4.57 kg/d milk yield at the start of the experiment) were blocked according to parity, milk yield, and days in milk and used in a 4 × 4 Latin square design experiment with 21-d periods, where the last 7 d were used for sampling and data analysis. Treatments were: 1) Mycotoxin group (MTX), basal diet (BD) without anti-mycotoxin feed additives; 2) Hydrated sodium calcium aluminosilicate (HSCA), HSCA added to the BD at 25g/cow/d; 3) Mycotoxin deactivator 15 (MD15), MD (Mycofix® Plus, dsm-firmenich) added to the BD at 15 g/cow/d; and 4) Mycotoxin deactivator 30 (MD30), MD added to the BD at 30 g/cow/d. Cows from all treatments were challenged with a blend of mycotoxins containing 404 µg aflatoxins B1 (AFB1), 5,025 µg deoxynivalenol (DON), 8,046 µg fumonisins (FUM), 195 µg T2 toxin (T2), and 2,034 µg of zearalenone (ZEN) added daily to the BD during the last 7 d of each period. Neither performance (milk yield and composition) nor nutrient digestibility was affected by treatments. All additives reduced aflatoxin M1 (AFM1) concentration in milk, whereas MD15 and MD30 group had lower excretion of AFM1 in milk than HSCA. DON, FUM, T2, or ZEN were not detected in milk of MD15 and MD30. Concentrations in milk of DON, FUM, T2, and ZEN were similar between MTX and HSCA. Except for AFM1, none of the analyzed mycotoxins were detected in urine of MD30 group. Comparing HSCA to MD treatments, the concentration of AFM1 was greater for HSCA, whereas MD30 was more efficient at reducing AFM1 in urine than MD15. AFM1, DON, FUM, and ZEN were not detected in the plasma of cows fed MD30, and DON was also not detected in MD15 group. Plasma concentration of FUM was lower for MD15, similar plasma FUM concentration was reported for HSCA and MTX. Plasma concentration of ZEN was lower for MD15 than MTX and HSCA. Serum concentrations of haptoglobin and hepatic enzymes were not affected by treatments. Blood concentration of sodium was lower in HSCA compared with MD15 and MD30 groups. In conclusion, the mycotoxin deactivator proved to be effective in reducing the secretion of mycotoxins in milk, urine, and blood plasma, regardless of the dosage. This reduction was achieved without adverse effects on milk production or total-tract digestibility in cows fed multi-mycotoxin-contaminated diets over a short-term period. Greater reductions in mycotoxin secretion were observed with full dose of MD.

3.
J Environ Manage ; 365: 121576, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38955045

RESUMEN

Savannas and grasslands have lost almost 50% of their original cover worldwide. Therefore, the development of methods and information on open-canopy ecosystem restoration is urgent for the inclusion of these ecosystems into global and regional priorities. In the Brazilian savanna, the most diverse savanna in the world, restoration efforts focused on open ecosystems have been virtually absent, but have increased in the last 10 years. Such efforts are frequently threatened by invasive exotic grasses (IEG) that invade and dominate areas excluding native species, oftentimes aided by altered soil conditions. Long-term studies of savanna restoration trajectories are rare. In this study, we surveyed 22 savanna restoration areas established two to ten years before the study with similar restoration methods to assess their current status. We show that the current restoration methods are successful in establishing native species and allowing species turnover but they are threatened by IEG. Restoration success varies and is affected by soil conditions, IEG landscape cover and post-sowing weeding. Despite that, the simultaneous introduction of different plant functional groups allows turnover from fast to slow-growing plants. Establishing savanna native species is possible at an operational scale with current knowledge and techniques. However, native species establishment fails to prevent IEG reinfestation, which needs to be managed in restoration efforts in the Brazilian savanna.

4.
Proc Biol Sci ; 290(1990): 20222203, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36629117

RESUMEN

Abandonment of agricultural lands promotes the global expansion of secondary forests, which are critical for preserving biodiversity and ecosystem functions and services. Such roles largely depend, however, on two essential successional attributes, trajectory and recovery rate, which are expected to depend on landscape-scale forest cover in nonlinear ways. Using a multi-scale approach and a large vegetation dataset (843 plots, 3511 tree species) from 22 secondary forest chronosequences distributed across the Neotropics, we show that successional trajectories of woody plant species richness, stem density and basal area are less predictable in landscapes (4 km radius) with intermediate (40-60%) forest cover than in landscapes with high (greater than 60%) forest cover. This supports theory suggesting that high spatial and environmental heterogeneity in intermediately deforested landscapes can increase the variation of key ecological factors for forest recovery (e.g. seed dispersal and seedling recruitment), increasing the uncertainty of successional trajectories. Regarding the recovery rate, only species richness is positively related to forest cover in relatively small (1 km radius) landscapes. These findings highlight the importance of using a spatially explicit landscape approach in restoration initiatives and suggest that these initiatives can be more effective in more forested landscapes, especially if implemented across spatial extents of 1-4 km radius.


Asunto(s)
Ecosistema , Bosques , Biodiversidad , Árboles , Plantas
5.
J Environ Manage ; 330: 117185, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36603271

RESUMEN

The Cerrado region comprises the world's most biodiverse savanna and the largest cultivated pastures for cattle in Brazil. Forty percent of these pastures are unproductive or degraded, with bare soil and native vegetation increasingly replacing exotic forage grasses. This study sought to investigate the regeneration of native vegetation in the pastures of the Cerrado and to evaluate the contribution of biophysical, land management, and landscape attributes to this process. Across the Cerrado, we analyzed pasture plant communities and the attributes of pasture management intensification, fire events, landscape native vegetation cover, and climate and soil types of 93 active pastures and 15 abandoned pastures. For the abandoned pastures, time since abandonment was an additional variable. On actively cultivated pastures, savanna regeneration varied from 0 to 70%, with a diversity of herbs and woody species. Pasture management was the main predictor of savanna regeneration on cultivated pastures. On abandoned pastures, time since abandonment was the main predictor. Exotic grass cover had a strong negative relationship with savanna regeneration and they were present even in pastures abandoned for 44 years. Our study reveals the potential of natural regeneration of the Cerrado and its particular predictors. The occurrence of pastures with high natural regeneration indicates that national policies can promote native vegetation restoration and silvopastoral systems with predictable, low cost implementation.


Asunto(s)
Ecosistema , Pradera , Animales , Bovinos , Bosques , Biodiversidad , Suelo , Poaceae , Brasil
6.
Environ Monit Assess ; 195(9): 1038, 2023 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-37572158

RESUMEN

The Brazilian Cerrado is a hotspot of biodiversity conservation and an important global agricultural region. Cultivated pastures under different degradation levels are dominant in the landscape and are being targeted for sustainable agricultural intensification and restoration of native vegetation. In this study, we classified the cultivated pastures of the Brazilian Cerrado according to their potential for natural regeneration, based on field surveys and environmental predictors. We surveyed the native vegetation cover in 186 plots distributed along 93 cultivated pastures. The environmental predictors considered in this study were the proportion of sand in the soil, cation exchange capacity, climate water deficit, pasture age, slope, and pasture vigor index. We then applied the Random Forest regression algorithm to predict and map the cultivated pastures according to their potential for natural regeneration in the 19 Cerrado ecoregions. The potential for natural regeneration was classified into low (< 30% of native plant cover), medium (30-50%), and high (> 50%). Our prediction explained 75% of the data variability. Most of the cultivated pastures presented medium potential for natural regeneration (57%), while 31% and 12% presented high and low potentials, respectively. Cultivated pastures in ecoregions with high mechanization, due to their high water availability and extensive flat terrains, presented low potential for natural regeneration. This first attempt to map the potential for natural regeneration in the cultivated pastures of the Brazilian Cerrado can be used as a proxy for planning low-cost and predictable restoration or environmentally sustainable intensification in this major type of land use found in this biome.


Asunto(s)
Conservación de los Recursos Naturales , Monitoreo del Ambiente , Brasil , Ecosistema , Biodiversidad , Agricultura , Agua
7.
Brain ; 144(6): 1898-1910, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-33710282

RESUMEN

Schizophrenia is associated with marked impairments in social cognition. However, the neural correlates of these deficits remain unclear. Here we use naturalistic stimuli to examine the role of the right temporoparietal junction/posterior superior temporal sulcus (TPJ-pSTS)-an integrative hub for the cortical networks pertinent to the understanding complex social situations-in social inference, a key component of social cognition, in schizophrenia. Twenty-seven schizophrenia participants and 21 healthy control subjects watched a clip of the film The Good, the Bad and the Ugly while high resolution multiband functional MRI images were collected. We used inter-subject correlation to measure the evoked activity, which we then compared to social cognition as measured by The Awareness of Social Inference Test (TASIT). We also compared between groups the TPJ-pSTS blood oxygen level-dependent activity (i) relationship with the motion content in the film; (ii) synchronization with other cortical areas involved in the viewing of the movie; and (iii) relationship with the frequency of saccades made during the movie. Activation deficits were greatest in middle TPJ (TPJm) and correlated significantly with impaired TASIT performance across groups. Follow-up analyses of the TPJ-pSTS revealed decreased synchronization with other cortical areas, decreased correlation with the motion content of the movie, and decreased correlation with the saccades made during the movie. The functional impairment of the TPJm, a hub area in the middle of the TPJ-pSTS, predicts deficits in social inference in schizophrenia participants by disrupting the integration of visual motion processing into the TPJ. This disrupted integration then affects the use of the TPJ to guide saccades during the visual scanning of the movie clip. These findings suggest that the TPJ may be a treatment target for improving deficits in a key component of social cognition in schizophrenia participants.


Asunto(s)
Lóbulo Parietal/fisiopatología , Esquizofrenia/fisiopatología , Cognición Social , Lóbulo Temporal/fisiopatología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino
8.
PLoS Pathog ; 14(4): e1006983, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29614111

RESUMEN

[This corrects the article DOI: 10.1371/journal.ppat.1006906.].

9.
PLoS Pathog ; 14(3): e1006906, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29518153

RESUMEN

HIV-1 arose as the result of spillover of simian immunodeficiency viruses (SIVs) from great apes in Africa, namely from chimpanzees and gorillas. Chimpanzees and gorillas were, themselves, infected with SIV after virus spillover from African monkeys. During spillover events, SIV is thought to require adaptation to the new host species. The host barriers that drive viral adaptation have predominantly been attributed to restriction factors, rather than cofactors (host proteins exploited to promote viral replication). Here, we consider the role of one cofactor, RanBP2, in providing a barrier that drove viral genome evolution during SIV spillover events. RanBP2 (also known as Nup358) is a component of the nuclear pore complex known to facilitate nuclear entry of HIV-1. Our data suggest that transmission of SIV from monkeys to chimpanzees, and then from chimpanzees to gorillas, both coincided with changes in the viral capsid that allowed interaction with RanBP2 of the new host species. However, human RanBP2 subsequently provided no barrier to the zoonotic transmission of SIV from chimpanzees or gorillas, indicating that chimpanzee- and gorilla-adapted SIVs are pre-adapted to humans in this regard. Our observations are in agreement with RanBP2 driving virus evolution during cross-species transmissions of SIV, particularly in the transmissions to and between great ape species.


Asunto(s)
Evolución Biológica , Infecciones por VIH/virología , Chaperonas Moleculares/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Zoonosis/virología , África , Secuencia de Aminoácidos , Animales , Infecciones por VIH/metabolismo , Infecciones por VIH/transmisión , VIH-1/patogenicidad , Especificidad del Huésped , Humanos , Chaperonas Moleculares/genética , Proteínas de Complejo Poro Nuclear/genética , Filogenia , Primates , Homología de Secuencia , Síndrome de Inmunodeficiencia Adquirida del Simio/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/transmisión , Virus de la Inmunodeficiencia de los Simios/patogenicidad , Especificidad de la Especie , Replicación Viral , Zoonosis/metabolismo , Zoonosis/transmisión
10.
AAPS PharmSciTech ; 21(7): 255, 2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32888072

RESUMEN

The administration of medicines by the oral route is the most used approach for being very convenient. Although it is the most popular, this route also has absorption, and consequently, bioavailability limitations. In this sense, several pharmacotechnical strategies have been used to improve drug absorption, one of which is the use of permeation promoters. Papain is a very versatile plant enzyme that can be used as a permeation promoter of various active compounds. This study aimed to evaluate the safety of papain and the formulation of native papain minitablets to promote in vitro permeation of furosemide through an innovative biomimetic triple co-culture model of Caco-2, HT29-MTX, and Raji cells. Regarding permeation, furosemide and metaprolol concentrations are determined with HPLC; those are used to calculate Papp. Monolayer integrity was evaluated using TEER and Lucifer Yellow. In the presence of papain, TEER decreased two-fold and the Papp of furosemide increased six-fold. The results suggest that native papain minitablets can be used as therapeutic adjuvants to enhance the permeation of drugs significantly improving bioavailability.


Asunto(s)
Diuréticos/farmacocinética , Furosemida/farmacocinética , Mucosa Intestinal/metabolismo , Papaína/administración & dosificación , Comprimidos , Disponibilidad Biológica , Células CACO-2 , Técnicas de Cocultivo , Diuréticos/administración & dosificación , Furosemida/administración & dosificación , Células HT29 , Humanos , Técnicas In Vitro , Absorción Intestinal , Permeabilidad
11.
Fungal Genet Biol ; 122: 1-10, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30339831

RESUMEN

Organic acids are recognized as one of the most prevalent compounds in ecosystems, thus the transport and assimilation of these molecules represent an adaptive advantage for organisms. The AceTr family members are associated with the active transport of organic acids, namely acetate and succinate. The phylogenetic analysis shows this family is dispersed in the tree of life. However, in eukaryotes, it is almost limited to microbes, though reaching a prevalence close to 100% in fungi, with an essential role in spore development. Aiming at deepening the knowledge in this family, we studied the acetate permease AceP from Methanosarcina acetivorans, as the first functionally characterized archaeal member of this family. Furthermore, we demonstrate that the yeast Gpr1 from Yarrowia lipolytica is an acetate permease, whereas the Ady2 closest homologue in Saccharomyces cerevisiae, Fun34, has no role in acetate uptake. In this work, we describe the functional role of the AceTr conserved motif NPAPLGL(M/S). We further unveiled the role of the amino acid residues R122 and Q125 of SatP as essential for protein activity.


Asunto(s)
Transporte Biológico/genética , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana/genética , Methanosarcina/enzimología , Ácido Acético/química , Ácido Acético/metabolismo , Secuencias de Aminoácidos/genética , Secuencia de Aminoácidos , Proteínas de la Membrana/química , Proteínas de Transporte de Membrana/química , Methanosarcina/genética , Filogenia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Ácido Succínico/química , Ácido Succínico/metabolismo , Yarrowia/genética
12.
BMC Evol Biol ; 17(1): 88, 2017 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-28335724

RESUMEN

BACKGROUND: India is a patchwork of tribal and non-tribal populations that speak many different languages from various language families. Indo-European, spoken across northern and central India, and also in Pakistan and Bangladesh, has been frequently connected to the so-called "Indo-Aryan invasions" from Central Asia ~3.5 ka and the establishment of the caste system, but the extent of immigration at this time remains extremely controversial. South India, on the other hand, is dominated by Dravidian languages. India displays a high level of endogamy due to its strict social boundaries, and high genetic drift as a result of long-term isolation which, together with a very complex history, makes the genetic study of Indian populations challenging. RESULTS: We have combined a detailed, high-resolution mitogenome analysis with summaries of autosomal data and Y-chromosome lineages to establish a settlement chronology for the Indian Subcontinent. Maternal lineages document the earliest settlement ~55-65 ka (thousand years ago), and major population shifts in the later Pleistocene that explain previous dating discrepancies and neutrality violation. Whilst current genome-wide analyses conflate all dispersals from Southwest and Central Asia, we were able to tease out from the mitogenome data distinct dispersal episodes dating from between the Last Glacial Maximum to the Bronze Age. Moreover, we found an extremely marked sex bias by comparing the different genetic systems. CONCLUSIONS: Maternal lineages primarily reflect earlier, pre-Holocene processes, and paternal lineages predominantly episodes within the last 10 ka. In particular, genetic influx from Central Asia in the Bronze Age was strongly male-driven, consistent with the patriarchal, patrilocal and patrilineal social structure attributed to the inferred pastoralist early Indo-European society. This was part of a much wider process of Indo-European expansion, with an ultimate source in the Pontic-Caspian region, which carried closely related Y-chromosome lineages, a smaller fraction of autosomal genome-wide variation and an even smaller fraction of mitogenomes across a vast swathe of Eurasia between 5 and 3.5 ka.


Asunto(s)
Genética de Población , Migración Humana , Asia Occidental , Cromosomas Humanos Y , Clima , ADN Mitocondrial/genética , Femenino , Variación Genética , Estudio de Asociación del Genoma Completo , Proyecto Genoma Humano , Humanos , India/etnología , Masculino
13.
Proc Biol Sci ; 284(1851)2017 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-28330913

RESUMEN

Important gaps remain in our understanding of the spread of farming into Europe, due partly to apparent contradictions between studies of contemporary genetic variation and ancient DNA. It seems clear that farming was introduced into central, northern, and eastern Europe from the south by pioneer colonization. It is often argued that these dispersals originated in the Near East, where the potential source genetic pool resembles that of the early European farmers, but clear ancient DNA evidence from Mediterranean Europe is lacking, and there are suggestions that Mediterranean Europe may have resembled the Near East more than the rest of Europe in the Mesolithic. Here, we test this proposal by dating mitogenome founder lineages from the Near East in different regions of Europe. We find that whereas the lineages date mainly to the Neolithic in central Europe and Iberia, they largely date to the Late Glacial period in central/eastern Mediterranean Europe. This supports a scenario in which the genetic pool of Mediterranean Europe was partly a result of Late Glacial expansions from a Near Eastern refuge, and that this formed an important source pool for subsequent Neolithic expansions into the rest of Europe.


Asunto(s)
ADN Antiguo/análisis , ADN Mitocondrial/análisis , Variación Genética , Genoma Humano , Etnicidad , Europa (Continente) , Efecto Fundador , Haplotipos , Humanos , Región Mediterránea , Medio Oriente , Población Blanca
14.
J Virol ; 90(6): 3056-64, 2015 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-26719253

RESUMEN

UNLABELLED: MxB restricts HIV-1 infection by directly interacting with the HIV-1 core, which is made of viral capsid; however, the contribution of MxB to the HIV-1 restriction observed in alpha interferon (IFN-α)-treated human cells is unknown. To understand this contribution, we used HIV-1 bearing the G208R capsid mutant (HIV-1-G208R), which overcomes the restriction imposed by cells expressing MxB. Here we showed that the reason why MxB does not block HIV-1-G208R is that MxB does not interact with HIV-1 cores bearing the mutation G208R. To understand whether MxB contributes to the HIV-1 restriction imposed by IFN-α-treated human cells, we challenged IFN-α-treated cells with HIV-G208R and found that MxB does not contribute to the restriction imposed by IFN-α-treated cells. To more directly test the contribution of MxB, we challenged IFN-α-treated human cells that are knocked out for the expression of MxB with HIV-1. These experiments suggested that MxB does not contribute to the HIV-1 restriction observed in IFN-α-treated human cells. IMPORTANCE: MxB is a restriction factor that blocks HIV-1 infection in human cells. Although it has been postulated that MxB is the factor that blocks HIV-1 infection in IFN-α-treated cells, this is a hard concept to grasp due to the great number of genes that are induced by IFN-α in cells from the immune system. The work presented here elegantly demonstrates that MxB has minimal or no contribution to the ability of IFN-α-treated human cells to block HIV-1 infection. Furthermore, this work suggests the presence of novel restriction factors in IFN-α-treated human cells that block HIV-1 infection.


Asunto(s)
VIH-1/inmunología , Interferón-alfa/metabolismo , Proteínas de Resistencia a Mixovirus/metabolismo , Línea Celular , Técnicas de Inactivación de Genes , Humanos , Proteínas de Resistencia a Mixovirus/genética
15.
J Virol ; 89(16): 8599-610, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26063425

RESUMEN

UNLABELLED: The interferon alpha (IFN-α)-inducible restriction factor MxB blocks HIV-1 infection after reverse transcription but prior to integration. Fate-of-capsid experiments have correlated the ability of MxB to block HIV-1 infection with stabilization of viral cores during infection. We previously demonstrated that HIV-1 restriction by MxB requires capsid binding and oligomerization. Deletion and gain-of-function experiments have mapped the HIV-1 restriction ability of MxB to its N-terminal 25 amino acids. This report reveals that the N-terminal 25 amino acids of MxB exhibit two separate functions: (i) the ability of MxB to bind to HIV-1 capsid and (ii) the nuclear localization signal of MxB, which is important for the ability of MxB to shuttle into the nucleus. To understand whether MxB restriction of HIV-1 requires capsid binding and/or nuclear localization, we genetically separated these two functions and evaluated their contributions to restriction. Our experiments demonstrated that the (11)RRR(13) motif is important for the ability of MxB to bind capsid and to restrict HIV-1 infection. These experiments suggested that capsid binding is necessary for the ability of MxB to block HIV-1 infection. Separately from the capsid binding function of MxB, we found that residues (20)KY(21) regulate the ability of the N-terminal 25 amino acids of MxB to function as a nuclear localization signal; however, the ability of the N-terminal 25 amino acids to function as a nuclear localization signal was not required for restriction. IMPORTANCE: MxB/Mx2 blocks HIV-1 infection in cells from the immune system. MxB blocks infection by preventing the uncoating process of HIV-1. The ability of MxB to block HIV-1 infection requires that MxB binds to the HIV-1 core by using its N-terminal domain. The present study shows that MxB uses residues (11)RRR(13) to bind to the HIV-1 core during infection and that these residues are required for the ability of MxB to block HIV-1 infection. We also found that residues (20)KY(21) constitute a nuclear localization signal that is not required for the ability of MxB to block HIV-1 infection.


Asunto(s)
Cápside/metabolismo , Infecciones por VIH/prevención & control , VIH-1/metabolismo , Proteínas de Resistencia a Mixovirus/metabolismo , Secuencias de Aminoácidos/genética , Western Blotting , Cartilla de ADN/genética , Técnica del Anticuerpo Fluorescente Indirecta , Vectores Genéticos/genética , Infecciones por VIH/metabolismo , Humanos , Luciferasas , Proteínas de Resistencia a Mixovirus/genética , Señales de Localización Nuclear/genética , Unión Proteica , Reacción en Cadena en Tiempo Real de la Polimerasa
16.
Retrovirology ; 11: 68, 2014 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-25123063

RESUMEN

BACKGROUND: The IFN-α-inducible restriction factor MxB blocks HIV-1 infection after reverse transcription but prior to integration. Genetic evidence suggested that capsid is the viral determinant for restriction by MxB. This work explores the ability of MxB to bind to the HIV-1 core, and the role of capsid-binding in restriction. RESULTS: We showed that MxB binds to the HIV-1 core and that this interaction leads to inhibition of the uncoating process of HIV-1. These results identify MxB as an endogenously expressed protein with the ability to inhibit HIV-1 uncoating. In addition, we found that a benzimidazole-based compound known to have a binding pocket on the surface of the HIV-1 capsid prevents the binding of MxB to capsid. The use of this small-molecule identified the MxB binding region on the surface of the HIV-1 core. Domain mapping experiments revealed the following requirements for restriction: 1) MxB binding to the HIV-1 capsid, which requires the 20 N-terminal amino acids, and 2) oligomerization of MxB, which is mediated by the C-terminal domain provides the avidity for the interaction of MxB with the HIV-1 core. CONCLUSIONS: Overall our work establishes that MxB binds to the HIV-1 core and inhibits the uncoating process of HIV-1. Moreover, we demonstrated that HIV-1 restriction by MxB requires capsid binding and oligomerization.


Asunto(s)
Infecciones por VIH/metabolismo , Infecciones por VIH/virología , VIH-1/metabolismo , Proteínas de Resistencia a Mixovirus/metabolismo , Proteínas del Núcleo Viral/metabolismo , Cápside/metabolismo , Línea Celular Tumoral , Células HeLa , Humanos , Unión Proteica , Células U937
17.
Artículo en Inglés | MEDLINE | ID: mdl-24525380

RESUMEN

The present study was conducted in order to evaluate the effect of Brazilian propolis (AF-08; 5, 10, 15, 30, 50, 100, and 200µg/mL) in protecting CHO-K1 cells against genotoxic and cytotoxic damage and clonogenic death induced by (60)Co gamma-radiation (1.0, 2.0, 4.0, and 6.0Gy). For this purpose, three interlinked endpoints were analyzed: induction of DNA damage by use of the micronucleus (MN) test (genotoxic damage), cell viability by means of the MTS assay, and differential staining (cytotoxic damage) and clonogenic death via the colony-formation test (cytotoxic damage). The MN test revealed that propolis alone (5-100µg/mL) was not genotoxic up to 100µg/mL and that 30µg/mL of propolis reduced the radiation-induced DNA damage (∼56% reduction, p<0.05), exhibiting a radio-protective effect on irradiated CHO-K1 cells. On the other hand, analysis of cytotoxicity showed that a concentration of 50µg/mL presented a significant proliferative effect (p<0.001) when associated with radiation, decreasing the percentage of necrotic cells (p<0.01). No mediated cytotoxic effect was found, but the concentration of 200µg/mL was toxic when analyzed at 24 and 48h via the differential staining technique, but not at 72h after irradiation, analyzed with the MTS assay. Differential staining also showed that necrosis was the main death modality in irradiated cells and that apoptosis was induced only at the toxic concentration of propolis (200µg/mL). Concerning the clonogenic capacity, a concentration of 50µg/mL also exhibited a significant stimulating effect on cell proliferation (p<0.001), in agreement with the data from differential staining. Taken together, these data suggest that the use of propolis AF-08 for the prevention of the adverse effects of ionizing radiation is promising. Nevertheless, additional investigations are necessary for a better understanding of potential applications of propolis to improve human health.


Asunto(s)
Daño del ADN/efectos de los fármacos , Rayos gamma/efectos adversos , Micronúcleos con Defecto Cromosómico , Própolis/farmacología , Protectores contra Radiación/farmacología , Animales , Brasil , Células CHO , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Radioisótopos de Cobalto , Ensayo de Unidades Formadoras de Colonias , Cricetinae , Cricetulus , Relación Dosis-Respuesta a Droga , Micronúcleos con Defecto Cromosómico/efectos de los fármacos , Micronúcleos con Defecto Cromosómico/efectos de la radiación , Própolis/administración & dosificación , Protectores contra Radiación/administración & dosificación
18.
Int J Biol Macromol ; 258(Pt 1): 128663, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38092102

RESUMEN

The aqueous batch extraction of pectin from unripe Ponkan mandarin was evaluated for potential application in the food industry. A small central composite design with 4 variables (temperature, volume to mass ratio, pH, and mean particle size) and 3 levels was applied for pectin extraction optimization. Also, the kinetic of the pectin yield extraction was investigated at temperatures 70-90 °C, stirring rate of 100-700 rpm, ultrasound pretreatment system, and modeling using four mathematical models. The pectin extraction process was evaluated by yield of pectin and esterification degree. FTIR, TGA, and DTA were performed to evaluate the quality of pectin obtained. The small central composite design demonstrated that temperature and volume to mass ratio were significant variables, and the highest yield of pectin extraction was 11.62 % obtained at temperature and volume to molar ratio of 81.9 °C and 33.9 v/w %, respectively. Besides, the esterification degree showed higher than 70 % for all extraction conditions, suggesting high methoxyl pectin. The kinetics showed the stirring rate and the ultrasound pretreatment did not cause any significant alteration, while high temperatures proved to be beneficial to the rate and the yield of the pectin extraction. The best fit was provided by Fick's law, suggesting the extraction process is limited by internal mass transfer. FTIR showed the functional groups expected for pectin, and TGA and DTA indicated that the pectin obtained is proper for most food products, as only above 200 °C the pectin should degrade.


Asunto(s)
Citrus , Pectinas , Solventes , Temperatura , Agua
19.
Zootaxa ; 5397(4): 563-577, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38221184

RESUMEN

Enneothrips is a lineage of leaf-feeding thrips conventionally placed in the Anaphothrips genus-group (Thripinae) and exclusively found in the Neotropics. Here we describe E. amazonicus sp. n., E. fulbrightae sp. n. and E. manauara sp. n. from the Brazilian Amazon and E. atlanticus sp. n. from the Brazilian Atlantic Forest, together with an illustrated key to all ten species now recognized in the genus.


Asunto(s)
Thysanoptera , Animales , Hojas de la Planta , Bosques
20.
Nanotheranostics ; 8(1): 112-126, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38164500

RESUMEN

Background: Nanotechnology has revolutionized medicine, especially in oncological treatments. Gold nanoparticles (AuNPs) stand out as an innovative alternative due to their biocompatibility, potential for surface modification, and effectiveness in radiotherapeutic techniques. Given that prostate cancer ranks as one of the leading malignancies among men, there's a pressing need to investigate new therapeutic approaches. Methods: AuNPs coated with bovine serum albumin (BSA) were synthesized and their cytotoxicity was assessed against prostate tumor cell lines (LNCaP and PC-3), healthy prostate cells (RWPE-1), and endothelial control cells (HUVEC) using the MTS/PMS assay. For in vivo studies, BALB/C Nude mice were employed to gauge the therapeutic efficacy, biodistribution, and hematological implications post-treatment with BSA-coated AuNPs. Results: The BSA-coated AuNPs exhibited cytotoxic potential against PC-3 and LNCaP lines, while interactions with RWPE-1 and HUVEC remain subjects for further scrutiny. Within animal models, a diverse therapeutic response was observed, with certain instances indicating complete tumor regression. Biodistribution data emphasized the nanoparticles' affinity towards particular organs, and the majority of hematological indicators aligned with normative standards. Conclusions: BSA-coated AuNPs manifest substantial promise as therapeutic tools in treating prostate cancer. The present research not only accentuates the nanoparticles' efficacy but also stresses the imperative of optimization to ascertain both selectivity and safety. Such findings illuminate a promising trajectory for avant-garde therapeutic modalities, holding substantial implications for public health advancements.


Asunto(s)
Nanopartículas del Metal , Neoplasias de la Próstata , Masculino , Animales , Ratones , Humanos , Oro/farmacología , Próstata/metabolismo , Albúmina Sérica Bovina/metabolismo , Distribución Tisular , Ratones Desnudos , Nanopartículas del Metal/uso terapéutico , Ratones Endogámicos BALB C , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/metabolismo , Radioisótopos
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