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Background: Hypersensitivity to beta-lactam (BL) antibiotics is one of the most frequent reported drug allergies. In our population, it is common to find labels of BL allergy in electronic medical records (EMRs) that have not been assessed. The objective of our study was to detect patients with beta-lactam allergy labels in their EMRs and to assess how many of them are false after a correct diagnostic evaluation. Methods: A multicentre prospective study was performed with patients labelled as allergic to BLs in their EMRs in the previous 5 years. Demographical and clinical data, as well as variables regarding the BL allergy label and the characteristics of the index reaction from clinical history and EMRs, were recorded. Then, diagnostic assessments including clinical history, skin tests (STs), and drug provocation tests (DPTs) were conducted in order to confirm or exclude the diagnosis of BL allergy. Results: A total of 249 patients completed the study, of which 160 (64.3%) were women with a median age of 57 years (interquartile range [IQR], 45-68). The most frequent BL allergy labels detected were for penicillin (124), amoxicillin/clavulanic acid (61), and amoxicillin (54). Of the 204 patients who underwent STs, 20.1% were positive. DPTs were performed in 224 patients, showing good tolerance in 87.1% of cases. After the allergy diagnosis work-up, 186 patients (74.7%) were diagnosed as non-allergic to BL antibiotics. Conclusion: In our study population, the number of patients labelled as allergic to BLs in their EMRs was similar to that in previously published studies, with proportions near to 75%-80% being falsely labelled as allergic to BLs.
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Fungal cell walls are dynamic extracellular matrices that enable efficient adaptation to changing environments. While the cell wall compositions of yeasts, human, and plant pathogenic fungi have been studied to some extent, the cell walls of mycoparasites remain poorly characterized. Trichoderma species comprise a diverse group of soil fungi with different survival strategies and lifestyles. The comparative study of cell wall carbohydrate-active enzymes in 13 Trichoderma spp. revealed that the types of enzymes involved in chitin and chitosan metabolism are phylogenetically distant between mycoparasitic and saprotrophic species. Here, we compare the carbohydrate composition and function of the cell wall of a saprotrophic strain Trichoderma reesei with that of the mycoparasitic, biological control agent Trichoderma atroviride. Monosaccharide and glycosidic linkage analyses as well as dual in situ interaction assays showed that the cell wall polysaccharide composition is conserved between both species, except for the amounts of chitin detected. The results suggest that the observed accumulation of chitosan during mycoparasitism may prevent host recognition. Remarkably, Trichoderma atroviride undergoes dynamic cell wall adaptations during both vegetative development and mycoparasitism, which appears to be confirmed by an evolutionarily expanded group of specialized enzymes. Overall, our analyses support the notion that habitat specialization is reflected in cell wall architecture and that plastic chitin remodeling may confer an advantage to mycoparasites, ultimately enabling the successful invasion and parasitism of plant pathogens. This information may potentially be exploited for the control of crop diseases using biological agents. IMPORTANCE: Trichoderma species are emerging model fungi for the development of biocontrol agents and are used in industrial biotechnology as efficient enzyme producers. Fungal cell walls are complex structures that differ in carbohydrate, protein, and enzyme composition across taxa. Here, we present a chemical characterization of the cell walls of two Trichoderma spp., namely the predominantly saprotrophic Trichoderma reesei and the mycoparasite Trichoderma atroviride. Chemical profiling revealed that Trichoderma spp. remodel their cell wall to adapt to particular lifestyles, with dynamic changes during vegetative development. Importantly, we found that chitosan accumulation during mycoparasitism of a fungal host emerged as a sophisticated strategy underpinning an effective attack. These insights shed light on the molecular mechanisms that allow mycoparasites to overcome host defenses and can be exploited to improve the application of T. atroviride in biological pest control. Moreover, our results provide valuable information for targeting the fungal cell wall for therapeutic purposes.
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Parede Celular , Quitosana , Trichoderma , Parede Celular/metabolismo , Parede Celular/química , Quitosana/metabolismo , Trichoderma/metabolismo , Trichoderma/genética , Quitina/metabolismo , Polissacarídeos/metabolismo , Hypocreales/metabolismo , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Filogenia , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genéticaRESUMO
Root-knot nematodes are polyphagous parasitic nematodes that cause severe losses in the agriculture worldwide. They enter the root in the elongation zone and subtly migrate to the root meristem where they reach the vascular cylinder and establish a feeding site called gall. Inside the galls they induce a group of transfer cells that serve to nurture them along their parasitic stage, the giant cells. Galls and giant cells develop through a process of post-embryogenic organogenesis that involves manipulating different genetic regulatory networks within the cells, some of them through hijacking some molecular transducers of established plant developmental processes, such as lateral root formation or root regeneration. Galls/giant cells formation involves different mechanisms orchestrated by the nematode´s effectors that generate diverse plant responses in different plant tissues, some of them include sophisticated mechanisms to overcome plant defenses. Yet, the plant-nematode interaction is normally accompanied to dramatic transcriptomic changes within the galls and giant cells. It is therefore expected a key regulatory role of plant-transcription factors, coordinating both, the new organogenesis process induced by the RKNs and the plant response against the nematode. Knowing the role of plant-transcription factors participating in this process becomes essential for a clear understanding of the plant-RKNs interaction and provides an opportunity for the future development and design of directed control strategies. In this review, we present the existing knowledge of the TFs with a functional role in the plant-RKN interaction through a comprehensive analysis of current scientific literature and available transcriptomic data.
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MAIN CONCLUSION: Upon systemic S. indica colonization in split-root system cyst and root-knot nematodes benefit from endophyte-triggered carbon allocation and altered defense responses what significantly facilitates their development in A. thaliana. Serendipita indica is an endophytic fungus that establishes mutualistic relationships with different plants including Arabidopsis thaliana. It enhances host's growth and resistance to different abiotic and biotic stresses such as infestation by the cyst nematode Heterodera schachtii (CN). In this work, we show that S. indica also triggers similar direct reduction in development of the root-knot nematode Meloidogyne javanica (RKN) in A. thaliana. Further, to mimick the natural situation occurring frequently in soil where roots are unequally colonized by endophytes we used an in vitro split-root system with one half of A. thaliana root inoculated with S. indica and the other half infected with CN or RKN, respectively. Interestingly, in contrast to direct effects, systemic effects led to an increase in number of both nematodes. To elucidate this phenomenon, we focused on sugar metabolism and defense responses in systemic non-colonized roots of plants colonized by S. indica. We analyzed the expression of several SUSs and INVs as well as defense-related genes and measured sugar pools. The results show a significant downregulation of PDF1.2 as well as slightly increased sucrose levels in the non-colonized half of the root in three-chamber dish. Thus, we speculate that, in contrast to direct effects, both nematode species benefit from endophyte-triggered carbon allocation and altered defense responses in the systemic part of the root, which promotes their development. With this work, we highlight the complexity of this multilayered tripartite relationship and deliver new insights into sugar metabolism and plant defense responses during S. indica-nematode-plant interaction.
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Arabidopsis , Basidiomycota , Cistos , Tylenchoidea , Animais , Endófitos , Carbono , AçúcaresRESUMO
Background: The role of physician credentialing has been widely considered in quality and outcome improvement studies. However, the association between surgeon characteristics and health-care costs remains unclear. Methods: Our objective was to determine the association of orthopaedic surgeon characteristics with health outcomes and costs, utilizing Medicare data. We used 100% Fee-for-Service Medicare data from 2015 to 2019 to identify all patients ≥65 years of age who underwent 2 common orthopaedic surgical procedures, total hip and knee replacement. After determining whether the patients had been readmitted after discharge from their initial admission for surgery, we computed 3 metrics of total medical expenditure: the costs of the initial surgery admission and 30-day and 180-day episode-based bundles of care. Hierarchical linear regression and logistic regression models were used to evaluate patient and surgeon characteristics associated with care costs and the likelihood of readmission. Results: We identified 2,269 surgeons who performed total knee replacements on 298,934 patients and 1,426 surgeons who performed total hip replacements on 204,721 patients. Patient characteristics associated with higher initial surgery costs included increasing age, female sex, racial minority status, and a higher Charlson Comorbidity Index. Surgeon characteristics associated with lower readmission rates included practice in the Northeast region and a higher patient volume; having malpractice claims was associated with higher readmission rates. Conclusions: A higher volume of patients treated by the orthopaedic surgeon was associated with lower overall costs and readmission rates. Information on surgeons' malpractice claims and annual volume should be made publicly available to assist patients, payer networks, and hospitals in surgeon selection and oversight. These results could also inform the guidelines of physician credentialing organizations. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
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BACKGROUND: Disrupted circadian rhythms may result from a misalignment between the environmental cycles (due to shift work, sleep restriction, feeding at an unusual time of day) and endogenous rhythms or by physiological aging. Among the numerous adverse effects, disrupted rhythms affect the brain-gut axis, contributing to the pathogenesis of several diseases in the gastrointestinal tract, for example, abdominal pain, constipation, gastric dyspepsia, inflammatory bowel disease, irritable bowel syndrome, and others. METHODS: This study evaluated the rat gastric emptying, gastrointestinal motility, a clock gene, gut hormones, and the neuron activity on the nucleus of tractus solitarius (NTS), area postrema (AP), and the dorsal motor nucleus of the vagus (DMV) in rats with restricted food access to the rest phase for 4 weeks. KEY RESULTS: Our results show that food restricted to the rest light period disturbed the expression pattern of a series of transcripts, including metabolic and circadian regulation. Also, the secretion of gastrointestinal hormones, gastric emptying, intestinal motility, and NTS, AP, and DMV activity were altered. CONCLUSIONS & INFERENCES: These data indicate the importance of the time of the day food is ingested on the regulation of energy balance and the endocrine activity of the stomach and small intestine, emphasizing the importance of food as a powerful circadian synchronizer and an essential factor for the triggering of gastrointestinal diseases and metabolic problems. These findings offer a novel clue regarding the obesity-promoting effect attributed to feeding time and open the possibility of treating this and other intestinal disorders.
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Gastroenteropatias , Hormônios Gastrointestinais , Ratos , Animais , Estômago , Nervo Vago/fisiologia , Ritmo Circadiano/fisiologia , Hormônios Gastrointestinais/fisiologia , Neurônios , Gastroenteropatias/metabolismoRESUMO
Short sleep is linked to disturbances in glucose metabolism and may induce a prediabetic condition. The biological clock in the suprachiasmatic nucleus (SCN) regulates the glucose rhythm in the circulation and the sleep-wake cycle. SCN vasopressin neurons (SCNVP) control daily glycemia by regulating the entrance of glucose into the arcuate nucleus (ARC). Thus, we hypothesized that sleep delay may influence SCN neuronal activity. We, therefore, investigated the role of SCNVP when sleep is disrupted by forced locomotor activity. After 2 h of sleep delay, rats exhibited decreased SCNVP neuronal activity, a decrease in the glucose transporter GLUT1 expression in tanycytes lining the third ventricle, lowered glucose entrance into the ARC, and developed hyperglycemia. The association between reduced SCNVP neuronal activity and hyperglycemia in sleep-delayed rats was evidenced by injecting intracerebroventricular vasopressin; this increased GLUT1 immunoreactivity in tanycytes, thus promoting normoglycemia. Following sleep recovery, glucose levels decreased, whereas SCNVP neuronal activity increased. These results imply that sleep-delay-induced changes in SCNVP activity lead to glycemic impairment, inferring that disruption of biological clock function might represent a critical step in developing type 2 diabetes.
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Diabetes Mellitus Tipo 2 , Hiperglicemia , Ratos , Animais , Transportador de Glucose Tipo 1/metabolismo , Ritmo Circadiano/fisiologia , Diabetes Mellitus Tipo 2/metabolismo , Núcleo Supraquiasmático/fisiologia , Sono , Glucose/metabolismo , Hiperglicemia/metabolismo , Vasopressinas/metabolismoRESUMO
Children and adolescents are high consumers of Western diets (rich in fat and sugars), which is a risk factor for overweight and obesity. Moreover, the presence of anxiety and depression among this population has increased significantly. This study explores in young postweaning rats the association between Western diet consumption and the development of metabolic and behavioral disturbances. At postnatal day (PN) 24, Wistar rats of both sexes were weaned and assigned to a control or cafeteria diet (CAF) group. After short-term exposure, a group of rats was euthanized at PN31 to obtain abdominal fat pads and blood samples. Another group of rats was tested in the open-field test, splash test, anhedonia test, and social play across 11 days (PN32-42). The CAF groups exhibited a significantly high level of body fat, serum glucose, triglycerides, leptin, and HOMA index when compared to the control groups. Only CAF males exhibited anxiety-like and depression-like behavior. Present results indicate that postweaning short-term exposure to a CAF diet has immediate detrimental effects on metabolism in both sexes. However, only CAF males showed mood disturbances. This study provides evidence that a CAF diet exerts immediate effects on behavior and metabolism in the postweaning period and that sexes present differential vulnerability.
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Dieta , Obesidade , Feminino , Ratos , Masculino , Animais , Ratos Wistar , Obesidade/metabolismo , Ansiedade , Transtornos de AnsiedadeRESUMO
Cysts (CNs) and root-knot nematodes (RKNs) induce specialized feeding cells, syncytia, and giant cells (GCs), respectively, within plant roots. The plant tissues around the GCs usually by respond forming a root swelling called a gall that contains the GCs. The ontogenesis of feeding cells is different. GC formation is a process of new organogenesis from vascular cells, which are still not well characterized, that differentiate into GCs. In contrast, syncytia formation involves the fusion of adjacent cells that have already differentiated. Nonetheless, both feeding sites show an auxin maximum pertinent to feeding site formation. However, data on the molecular divergences and similarities between the formation of both feeding sites regarding auxin-responsive genes are still scarce. We studied genes from the auxin transduction pathways that are crucial during gall and lateral root (LR) development in the CN interaction by using promoter-reporter (GUS/LUC)transgenic lines, as well as loss of function lines of Arabidopsis. The promoters pGATA23 and several deletions of pmiR390a were active in syncytia, as were in galls, but pAHP6 or putative up-stream regulators as ARF5/7/19 were not active in syncytia. Additionally, none of these genes seemed to play a key role during cyst nematode establishment in Arabidopsis, as the infection rates in loss of function lines did not show significant differences compared to control Col-0 plants. Furthermore, the presence of only canonical AuxRe elements in their proximal promoter regions is highly correlated with their activation in galls/GCs (AHP6, LBD16), but those promoters active in syncytia (miR390, GATA23) carry AuxRe overlapping core cis-elements for other transcription factor families (i.e., bHLH, bZIP). Strikingly, in silico transcriptomic analysis showed very few genes upregulated by auxins common to those induced in GCs and syncytia, despite the high number of upregulated IAA responsive genes in syncytia and galls. The complex regulation of auxin transduction pathways, where different members of the auxin response factor (ARF) family may interact with other factors, and the differences in auxin sensitivity, as indicated by the lower induction of the DR5 sensor in syncytia than galls, among other factors, may explain the divergent regulation of auxin responsive genes in the two types of nematode feeding sites.
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Sugar solutions promote hedonic feeding and increase the risk of obesity and binge-type behavior. In rodents, ingestion of sugar solutions enhances dopamine release to mesolimbic regions, suggesting changes in hedonic intake and brain reward processes. Moreover, dopaminergic D2R/D3R receptors contribute to the hedonic intake of palatable solutions. Although the experimental evidence indicate that the dopaminergic D4 receptor (D4R) modulates feeding at homeostatic levels, it is currently unknown whether D4R also regulate the hedonic intake of sugar solutions. In this study, we evaluated the effect of the central blockade of D4R on the consumption of a 20% sucrose solution, the drinking microstructure parameters, and levels of locomotor activity in sated rats. In the first experiment, male Wistar rats were daily exposed to a 20% sugar solution in the first hour of the light phase of the light:dark cycle. On day 10, rats received i.c.v injections of the D4R antagonist, L-745870 (0, 1 or 2 µg/5 µl) and sucrose consumption and drinking microstructure parameters (latency to start drinking, bouts, drinking duration, bout size, inter-bout interval, time in activity and time in resting) were evaluated. In the second experiment, rats were trained to receive the 20% sucrose solution as described in experiment 1. On day 10, after the 1 h of sucrose access, the rats were placed in the open field for 5-min (habituation phase). Then, rats received i.c.v injections of L-745870 (0, 1 or 2 µg/ 5 µl), and were placed again in the open-field test for 10-min (pharmacological phase). The number or crosses trough squares and number of rears were scored for both the habituation and pharmacological phase. Here we found that administration of L-745870 decreased the consumption of sucrose in a dose-depended manner. Moreover, L-745870-treated rats displayed microstructural changes, including greater number of bouts and reduced drinking duration, bout size and inter-bout intervals. Furthermore, the number of crosses and number of rears in the open field test remained unchanged for habituation and pharmacological phase. Finally, present findings suggest that D4R modulates the consumption of sugar solutions by alteration of hedonic responses, but the contribution of homeostatic systems is discussed. These results open perspectives for the potential use of the D4R antagonists for treating obesity or binge-eating behavior.
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Inhabitants of urban areas are constantly exposed to light at night, which is an important environmental factor leading to circadian disruption. Streetlights filtering light through the windows and night dim light lamps are common sources of dim light at night (DLAN). The female population is susceptible to circadian disruption. The present study is aimed to determine the impact of DLAN on female Wistar rats circadian rhythms, metabolism, reproductive physiology, and behavior. After 5 weeks of DLAN exposure daily, oscillations in activity and body temperature of female rats are abolished. DLAN also decreases nocturnal food ingestion, which results in a diminishment in total food consumption. These alterations in the temporal organization of the body are associated with a significant decrease in melatonin plasmatic levels, reproductive disruptions, decreased exploration times, and marked anhedonia. This study highlights the importance of avoiding exposure to light at night, even at low intensities, to maintain the circadian organization of physiology, and denotes the great necessity of increasing the studies in females since the sexual dimorphism within the effects of desynchronizing protocols has been poorly studied.
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Atividade Motora , Fotoperíodo , Ratos , Feminino , Animais , Atividade Motora/fisiologia , Ratos Wistar , Ritmo Circadiano/fisiologia , LuzRESUMO
BACKGROUND: HIV disproportionally impacts Latino sexual minority men (SMM). Uptake of pre-exposure prophylaxis (PrEP), an effective biomedical intervention to prevent HIV, is low in this group compared with White SMM. Mobile health technology represents an innovative strategy to increase PrEP uptake among Latino SMM. OBJECTIVE: We aimed to describe the qualitative process leading to the development of SaludFindr, a comprehensive HIV prevention mobile app aiming to increase PrEP uptake, HIV testing, and condom use by Latino SMM. METHODS: We conducted 13 in-depth interviews with Latino SMM living in the Atlanta area to explore their main barriers and facilitators to PrEP uptake and to analyze their opinions of potential SaludFindr app functionalities. To explore potential app functions, we used HealthMindr, an existing HIV prevention app, as a template and added new proposed features intended to address the specific community needs. RESULTS: We identified general PrEP uptake barriers that, although common among non-Latino groups, had added complexities such as the influence of religion and family on stigma. Low perceived PrEP eligibility, intersectional stigma, lack of insurance, cost concerns, and misconceptions about PrEP side effects were described as general barriers. We also identified Latino-specific barriers that predominantly hinder access to existing services, including a scarcity of PrEP clinics that are prepared to provide culturally concordant services, limited availability of Spanish language information related to PrEP access, distrust of peers as credible sources of information, perceived ineligibility for low-cost services owing to undocumented status, fear of immigration authorities, and competing work obligations that prevent PrEP clinic attendance. Health care providers represented a trusted source of information, and 3 provider characteristics were identified as PrEP facilitators: familiarity with prescribing PrEP; being Latino; and being part of lesbian, gay, bisexual, transgender, queer, intersex, and asexual (LGBTQIA+) group or ally. The proposed app was very well accepted, with a particularly high interest in features that facilitate PrEP access, including a tailored list of clinics that meet the community needs and a private platform to seek PrEP information. Spanish language availability and free or low-cost PrEP care represented the 2 main clinic criteria that would facilitate PrEP uptake. Latino representation in clinic staff and providers; clinic perception as a safe space for undocumented patients; and LGBTQIA+ representation was listed as additional criteria. Only 8 of 47 clinics listed on the Centers for Diseases Control and Prevention PrEP locator website for the Atlanta area fulfilled at least 2 main criteria. CONCLUSIONS: This study provides further evidence of the substantial PrEP uptake barriers that Latino SMM face; exposes the urgent need to increase the number of accessible PrEP-providing clinics for Latino SMM; and proposes an innovative, community-driven, and mobile technology-based tool as a future intervention to overcome some of these barriers.
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Eating during the rest phase is associated with metabolic syndrome, proposed to result from a conflict between food consumption and the energy-saving state imposed by the circadian system. However, in nocturnal rodents, eating during the rest phase (day-feeding, DF) also implies food intake during light exposure. To investigate whether light exposure contributes to DF-induced metabolic impairments, animals receive food during the subjective day without light. A skeleton photoperiod (SP) is used to entrain rats to a 12:12 cycle with two short light pulses framing the subjective day. DF-induced adiposity is prevented by SP, suggesting that the conflict between light and feeding stimulates fat accumulation. However, all animals under SP conditions develop glucose intolerance regardless of their feeding schedule. Moreover, animals under SP with ad libitum or night-feeding have increased adiposity. SP animals show a delayed onset of the daily rise in body temperature and energy expenditure and shorter duration of nighttime activity, which may contribute to the metabolic disturbances. These data emphasize that metabolic homeostasis can only be achieved when all daily cycling variables are synchronized. Even small shifts in the alignment of different metabolic rhythms, such as those induced by SP, may predispose individuals to metabolic disease.
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Intolerância à Glucose , Fotoperíodo , Ratos , Animais , Adiposidade , Comportamento Alimentar , Ritmo Circadiano , Intolerância à Glucose/etiologia , Obesidade/etiologia , EsqueletoRESUMO
Parasites and pathogens are known to manipulate the host's endogenous signaling pathways to facilitate the infection process. In particular, plant-parasitic root-knot nematodes (RKN) are known to elicit auxin response at the infection sites, to aid the development of root galls as feeding sites for the parasites. Here we describe the role of local auxin synthesis induced during RKN infection. Exogenous application of auxin synthesis inhibitors decreased RKN gall formation rates, gall size and auxin response in galls, while auxin and auxin analogues produced the opposite effects, re-enforcing the notion that auxin positively regulates RKN gall formation. Among the auxin biosynthesis enzymes, YUCCA4 (YUC4) was found to be dramatically up-regulated during RKN infection, suggesting it may be a major contributor to the auxin accumulation during gall formation. However, yuc4-1 showed only very transient decrease in gall auxin levels and did not show significant changes in RKN infection rates, implying the loss of YUC4 is likely compensated by other auxin sources. Nevertheless, yuc4-1 plants produced significantly smaller galls with fewer mature females and egg masses, confirming that auxin synthesized by YUC4 is required for proper gall formation and RKN development within. Interestingly, YUC4 promoter was also activated during cyst nematode infection. These lines of evidence imply auxin biosynthesis from multiple sources, one of them being YUC4, is induced upon plant endoparasitic nematode invasion and likely contribute to their infections. The coordination of these different auxins adds another layer of complexity of hormonal regulations during plant parasitic nematode interaction.
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Light at night is an emergent problem for modern society. Rodents exposed to light at night develop a loss of circadian rhythms, which leads to increased adiposity, altered immune response, and increased growth of tumors. In female rats, constant light (LL) eliminates the estrous cycle leading to a state of persistent estrus. The suprachiasmatic nucleus (SCN) drives circadian rhythms, and it interacts with the neuroendocrine network necessary for reproductive function. Timed restricted feeding (RF) exerts a powerful entraining influence on the circadian system, and it can influence the SCN activity and can restore rhythmicity or accelerate re-entrainment in experimental conditions of shift work or jet lag. The present study explored RF in female rats exposed to LL, with the hypothesis that this cyclic condition can rescue or prevent the loss of daily rhythms and benefit the expression of the estrous cycle. Two different feeding schedules were explored: 1. A 12-h food/12-h fasting schedule applied to arrhythmic rats after 3 weeks in LL, visualized as a rescue strategy (LL + RFR, 3 weeks), or applied simultaneously with the first day of LL as a preventive strategy (LL + RFP, 6 weeks). 2. A 12-h window of food intake with food given in four distributed pulses (every 3 h), applied after 3 weeks in LL, as a rescue strategy (LL + PR, 3 weeks) or applied simultaneously with the first day of LL as a preventive strategy (LL + PP, 6 weeks). Here, we present evidence that scheduled feeding can drive daily rhythms of activity and temperature in rats exposed to LL. However, the protocol of distributed feeding pulses was more efficient to restore the day-night activity and core temperature as well as the c-Fos day-night change in the SCN. Likewise, the distributed feeding partially restored the estrous cycle and the ovary morphology under LL condition. Data here provided indicate that the 12-h feeding/12-h fasting window determines the rest-activity cycle and can benefit directly the circadian and reproductive function. Moreover, this effect is stronger when food is distributed along the 12 h of subjective night.
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The total global food demand is expected to increase up to 50% between 2010 and 2050; hence, there is a clear need to increase plant productivity with little or no damage to the environment. In this respect, biochar is a carbon-rich material derived from the pyrolysis of organic matter at high temperatures with a limited oxygen supply, with different physicochemical characteristics that depend on the feedstock and pyrolysis conditions. When used as a soil amendment, it has shown many positive environmental effects such as carbon sequestration, reduction of greenhouse gas emissions, and soil improvement. Biochar application has also shown huge benefits when applied to agri-systems, among them, the improvement of plant growth either in optimal conditions or under abiotic or biotic stress. Several mechanisms, such as enhancing the soil microbial diversity and thus increasing soil nutrient-cycling functions, improving soil physicochemical properties, stimulating the microbial colonization, or increasing soil P, K, or N content, have been described to exert these positive effects on plant growth, either alone or in combination with other resources. In addition, it can also improve the plant antioxidant defenses, an evident advantage for plant growth under stress conditions. Although agricultural residues are generated from a wide variety of crops, cereals account for more than half of the world's harvested area. Yet, in this review, we will focus on biochar obtained from residues of the most common and relevant cereal crops in terms of global production (rice, wheat, maize, and barley) and in their use as recycled residues to stimulate plant growth. The harvesting and processing of these crops generate a vast number and variety of residues that could be locally recycled into valuable products such as biochar, reducing the waste management problem and accomplishing the circular economy premise. However, very scarce literature focused on the use of biochar from a crop to improve its own growth is available. Herein, we present an overview of the literature focused on this topic, compiling most of the studies and discussing the urgent need to deepen into the molecular mechanisms and pathways involved in the beneficial effects of biochar on plant productivity.
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Root-knot nematodes (RKNs) induce giant cells (GCs) within galls which are characterized by large-scale gene repression at early stages. However, the epigenetic mechanism(s) underlying gene silencing is (are) still poorly characterized. DNA methylation in Arabidopsis galls induced by Meloidogyne javanica was studied at crucial infection stages (3 d post-infection (dpi) and 14 dpi) using enzymatic, cytological, and sequencing approaches. DNA methyltransferase mutants (met1, cmt2, cmt3, cmt2/3, drm1/2, ddc) and a DNA demethylase mutant (ros1), were analyzed for RKN resistance/tolerance, and galls were characterized by confocal microscopy and RNA-seq. Early galls were hypermethylated, and the GCs were found to be the major contributors to this hypermethylation, consistent with the very high degree of gene repression they exhibit. By contrast, medium/late galls showed no global increase in DNA methylation compared to uninfected roots, but exhibited large-scale redistribution of differentially methylated regions (DMRs). In line with these findings, it was also shown that DNA methylation and demethylation mutants showed impaired nematode reproduction and gall/GC-development. Moreover, siRNAs that were exclusively present in early galls accumulated at hypermethylated DMRs, overlapping mostly with retrotransposons in the CHG/CG contexts that might be involved in their repression, contributing to their stability/genome integrity. Promoter/gene methylation correlated with differentially expressed genes encoding proteins with basic cell functions. Both mechanisms are consistent with reprogramming host tissues for gall/GC formation. In conclusion, RNA-directed DNA methylation (RdDM; DRM2/1) pathways, maintenance methyltransferases (MET1/CMT3) and demethylation (ROS1) appear to be prominent mechanisms driving a dynamic regulation of the epigenetic landscape during RKN infection.
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Proteínas de Arabidopsis , Arabidopsis , Tylenchoidea , Animais , Arabidopsis/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Regulação da Expressão Gênica de Plantas , Metilação de DNA/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Tylenchoidea/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismoRESUMO
BACKGROUND: Many epidemiological studies revealed that shift work is associated with an increased risk of a number of pathologies, including cardiovascular diseases. An experimental model of shift work in rats has additionally been shown to recapitulate aspects of metabolic disorders observed in human shift workers, including increased fat content and impaired glucose tolerance, and used to demonstrate that restricting food consumption outside working hours prevents shift work-associated obesity and metabolic disturbance. However, the way distinct shift work parameters, such as type of work, quantity, and duration, affect cardiovascular function and the underlying mechanisms, remains poorly understood. Here, we used the rat as a model to characterize the effects of shift work in the heart and determine whether they can be modulated by restricting food intake during the normal active phase. RESULTS: We show that experimental shift work reprograms the heart cycling transcriptome independently of food consumption. While phases of rhythmic gene expression are distributed across the 24-h day in control rats, they are clustered towards discrete times in shift workers. Additionally, preventing food intake during shift work affects the expression level of hundreds of genes in the heart, including genes encoding components of the extracellular matrix and inflammatory markers found in transcriptional signatures associated with pressure overload and cardiac hypertrophy. Consistent with this, the heart of shift worker rats not eating during work hours, but having access to food outside of shift work, exhibits increased collagen 1 deposition and displays increased infiltration by immune cells. While maintaining food access during shift work has less effects on gene expression, genes found in transcriptional signatures of cardiac hypertrophy remain affected, and the heart of shift worker rats exhibits fibrosis without inflammation. CONCLUSIONS: Together, our findings unraveled differential effects of food consumption on remodeled transcriptional profiles of the heart in shift worker rats. They also provide insights into how shift work affects cardiac function and suggest that some interventions aiming at mitigating metabolic disorders in shift workers may have adverse effects on cardiovascular diseases.