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1.
Cell Biochem Funct ; 41(1): 128-137, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36515301

RESUMO

Dysfunction of the adipose tissue metabolism is considered as a significant hallmark of aging. It has been proposed that α-ß hydrolase domain containing 5 (ABHD5) plays a critical role in the control of lipolysis. However, the role of ABHD5 in the control of lipolysis during aging or exercise is unknown. Here we combined the experimental mouse model with transcriptomic analyzes by using murine and human databases to explore the role of ABHD5 in the adipose tissue during aging and in response to exercise. Transcriptomic data revealed a downregulation of Abhd5 messenger RNA levels in the subcutaneous white adipose tissue (scWAT) over time in individuals from 20 to 69 years old. Aged mice displayed dramatic reduction of ABHD5 protein content and lipolytic-related proteins in the scWAT. Interestingly, 4 weeks of high-intensity interval training increased ABHD5 protein level and restored the lipolytic pathway in the scWAT of aged mice. Altogether, our findings demonstrated that aging affects ABHD5 content in the adipose tissue of mice and humans. Conversely, exercise increases ABHD5 activity, recovering the lipolytic activity in aged mice.


Assuntos
Tecido Adiposo , Hidrolases , Animais , Camundongos , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Hidrolases/genética , Hidrolases/metabolismo , Tecido Adiposo/metabolismo , Proteínas/metabolismo , Lipólise/genética , Envelhecimento , 1-Acilglicerol-3-Fosfato O-Aciltransferase/genética , 1-Acilglicerol-3-Fosfato O-Aciltransferase/metabolismo
2.
Ecol Appl ; : e2781, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36398791

RESUMO

Global demand for crops will continue increasing over the next few decades to cover both food and biofuel needs. This demand will put further pressure to expand arable land and replace natural habitats. However, we are only beginning to understand the combined effects of agrochemicals and land use change on tropical freshwater biodiversity. Here, we analyzed how pond-dwelling anuran larvae respond to pond characteristics, landscape composition, and agrochemical contamination in a sugarcane-dominated agroecosystem in Brazil. Then, we used an information theoretical approach with generalized linear models to relate species richness and abundance to predictor variables. The variation in tadpole abundance was associated with both agrochemical concentration (e.g., Ametryn, Diuron, and Malathion) and landscape variables (e.g., percentage of forest, percentage of agriculture, and distance to the closest forest). The relationship between species abundance and agrochemicals was species-specific. For example, the abundance of Scinax fuscovarius and Physalaemus nattereri were negatively associated with Ametryn, and Dendropsophus nanus was negatively associated with Tebuthiuron, while that of Leptodactylus fuscus was positively associated with Malathion. Conversely, species richness was associated with distance to forest fragments and aquatic vegetation heterogeneity, but not agrochemicals. Although we were unable to assign a specific mechanism to the variation in tadpole abundance based on field observations, the lower abundance of three species in ponds with high concentrations of agrochemicals suggest they negatively impact some frog species inhabiting agroecosystems. We recommend conserving ponds near forest fragments, with abundant stratified vegetation, and far from agrochemical runoffs to safeguard more sensitive pond-breeding species.

3.
Phys Chem Chem Phys ; 24(47): 28870-28877, 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36426661

RESUMO

Quantum state tomography is an integral part of quantum computation and offers the starting point for the validation of various quantum devices. One of the central tasks in the field of state tomography is to reconstruct, with high fidelity, the quantum states of a quantum system. From an experiment on a real quantum device, one can obtain the mean measurement values of different operators. With such data as input, in this report we employ the maximal entropy formalism to construct the least biased mixed quantum state that is consistent with the given set of expectation values. Even though, in principle, the reported formalism is quite general and should work for an arbitrary set of observables, in practice we shall demonstrate the efficacy of the algorithm on an informationally complete (IC) set of Hermitian operators. Such a set possesses the advantage of uniquely specifying a single quantum state from which the experimental measurements have been sampled and hence renders the rare opportunity not only to construct a least-biased quantum state but even replicate the exact state prepared experimentally within a preset tolerance. The primary workhorse of the algorithm is reconstructing an energy function which we designate as the effective Hamiltonian of the system, and parameterizing it with Lagrange multipliers, according to the formalism of maximal entropy. These parameters are thereafter optimized variationally so that the reconstructed quantum state of the system converges to the true quantum state within an error threshold. To this end, we employ a parameterized quantum circuit and a hybrid quantum-classical variational algorithm to obtain such a target state, making our recipe easily implementable on a near-term quantum device.

4.
J Dairy Sci ; 105(10): 7986-7997, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055844

RESUMO

In this study, we developed and optimized a growth medium using various nitrogen sources for the cultivation of Lactobacillus delbrueckii ssp. bulgaricus, a probiotic and essential dairy starter culture. The composition of de Man, Rogosa, and Sharpe (MRS) culture medium was modified, and the nitrogen content was replaced by alternative nitrogen sources X-Seed Nucleo Max, X-Seed KAT, and X-Seed Carbo Max (Ohly GmbH) in various blends of 5 and 10 g/L. Results showed that bacterial growth was significantly higher when the nitrogen source blend of 10 g/L of KAT and 10 g/L of Carbo Max [KCMax (10/10)] was used. The optical densities of the Lb. bulgaricus strains were significantly higher in the KCMax (10/10) medium than in the MRS medium. There was no significance in bacterial counts for both the MRS and the KCMax (10/10) medium, and all bacterial counts were estimated at 8 log cfu/mL. The buffering capacity of the KCMax (10/10) medium was also tested and supplemented with l-histidine and was significantly higher than that of the MRS control medium. KCMax (10/10) also supported the freeze-stability and viability of the Lb.bulgaricus cells during freezing and freeze-drying operations. Our results suggest that the alternative nitrogen sources X-Seed Nucleo Max, X-Seed KAT and X-Seed Carbo Max can substantially support the growth of lactic acid bacteria as demonstrated with Lb. bulgaricus. These alternative nitrogen sources could thus be recommended for lactic acid bacteria fermentation and for the cultivation of dairy starter cultures.


Assuntos
Lactobacillales , Lactobacillus delbrueckii , Animais , Meios de Cultura , Fermentação , Histidina , Humanos , Nitrogênio , Iogurte/microbiologia
5.
J Vis Exp ; (184)2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35781528

RESUMO

Lactic acid bacteria (LAB) are essential dairy starter cultures that are significantly employed for the manufacture of fermented dairy products such as yogurt and cheese. LAB predominantly produce lactic acid as a major end product of fermentation, and they synthesize important metabolites that impart the organoleptic characteristics of fermented food products. LAB are fastidious bacteria that thrive in many environments when adequate nutritional requirements are fulfilled. The demand for superior LAB dairy starter cultures for fermentation applications in the food and dairy industry, has resulted in the need to provide viable and active cultures for all bioprocessing operations. The development of a standard protocol for ensuring the viability and enhanced functionality of LAB cultures in the laboratory as well as dairy processing environments is thus very critical. In addressing concerns linked to resuscitating weak, stressed, and injured LAB culture cells, a protocol that vividly outlines salient steps to recover, enhance cell regeneration, and improve metabolic functionality of LAB strains is of the utmost importance. The maintenance of culture purity, functionality, and viability for LAB starter cultures is likewise critical. Therefore, adherence to a unique protocol guideline will result in the promotion of fermentation performance for many LAB strains dedicated to fermentation and biotechnology processes. As a result, the Food Microbiology and Biotechnology Laboratory at North Carolina Agriculture and Technical State University has developed a standard protocol for the activation and quality control of selected LAB strains that has resulted in highly functional and viable LAB culture strains employed for fermentation research. The adaptation and recommendation of a protocol such as this for use in the dairy and food industry will help to ensure LAB viability and functionality for many applications.


Assuntos
Lactobacillales , Fermentação , Microbiologia de Alimentos , Humanos , Lactobacillales/metabolismo , Controle de Qualidade , Iogurte
6.
J Am Chem Soc ; 144(23): 10353-10360, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35640072

RESUMO

We report an approach for the online coupling of digital microfluidics (DMF) with mass spectrometry (MS) using a chip-integrated microspray hole (µSH). The technique uses an adapted electrostatic spray ionization (ESTASI) method to spray a portion of a sample droplet through a microhole in the cover plate, allowing its chemical content to be analyzed by MS. This eliminates the need for chip disassembly or the introduction of capillary emitters for MS analysis, as required by state-of-the-art. For the first time, this allows the essential advantage of a DMF device─free droplet movement─to be retained during MS analysis. The broad applicability of the developed seamless coupling of DMF and mass spectrometry was successfully applied to the study of various on-chip organic syntheses as well as protein and peptide analysis. In the case of a Hantzsch synthesis, we were able to show that the method is very well suited for monitoring even rapid chemical reactions that are completed in a few seconds. In addition, the strength of the low resource consumption in such on-chip microsyntheses was demonstrated by the example of enzymatic brominations, for which only a minute amount of a special haloperoxidase is required in the droplet. The unique selling point of this approach is that the analyzed droplet remains completely movable after the MS measurement and is available for subsequent on-DMF chip processes. This is illustrated here for the example of MS analysis of the starting materials in the corresponding droplets before they are combined to investigate the reaction progress by DMF-MS further. This technology enables the ongoing and almost unlimited tracking of multistep chemical processes in a DMF chip and offers exciting prospects for transforming digital microfluidics into automated synthesis platforms.


Assuntos
Microfluídica , Proteínas , Espectrometria de Massas , Microfluídica/métodos
7.
J Adv Med Educ Prof ; 10(2): 99-104, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35434146

RESUMO

Introduction: Empathy is one of the soft skills required for building rapport and having meaningful patient-doctor interaction. Its effect on academic performance at the undergraduate level amongst Pakistani medical students is not known. This study was done to assess the relationship between empathy and gender, and the academic performance of undergraduate medical students of Azad Kashmir. Methods: This cross-sectional study was done in Poonch Medical College, Azad Kashmir, Pakistan, from May 2018 to May 2019. The sample size for this study consisted of 200 students, determined by Krejcie and Morgan sample size determination chart. Students who agreed to participate in the study were enrolled according to convenience sampling using google forms. The Interpersonal Reactivity Index (IRI) questionnaire was utilized as the data collection tool. Data were analyzed using SPSS version 25. The ethical review board approved the study. Comparisons between males and females at the IRI questions level, IRI domains level, and total IRI were made using the Mann-Whitney U test. The Spearman Rank Correlation test was used to assess the correlation between academic performance, IRI domains, and total IRI scores. A one-way ANOVA test was done to assess the relationship between academic performance and their study years. Results: A total of one hundred and fifty-one students (males 83, females 68, response rate 75.5%) participated in the study from the third to the final year of medical college. The mean empathy scores of males and females were 90.76 ± 8.39 and 91.72 ± 9.76 (p-value = 0.552). On the empathic concern scale, female students had significantly higher empathy scores (25.44 ± 3.49) than males (23.78 ± 3.88) (p-value=0.008). No significant correlation was found between the empathy scores and academic performance, using Spearman's correlation test (p>0.05). Conclusion: Females showed significantly higher empathy scores than males for two Interpersonal Reactivity Index items and empathic concern scale. Overall, male and female students had similar total empathy scores. The relationship between empathy and academic performance was non-significant.

8.
Nanoscale ; 14(6): 2266-2276, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35080562

RESUMO

The fabrication of a flexible supercapacitor with state-of-the-art performance is described, based on a facile and low-cost fabrication method that encompasses aligned carbon nanotube arrays (ACNTA)-polyaniline/polydimethylsiloxane electrodes (ACNTA-PANI/PDMS). The ACNTA were partially embedded in PDMS to ensure excellent adhesion and integration whilst PANI was electrodeposited on its surface to improve energy storage properties. The supercapacitor structure and morphology were investigated by Raman spectroscopy and scanning electron microscopy (SEM), respectively. The energy storage properties of the electrodes were evaluated in two and three-electrode configurations. The maximum value of specific capacitance was 408 mF cm-2 (265 F g-1) at 1 mA cm-2, and a high energy density of 20 µW h cm-2 (25.5 W h kg-1) was achieved at a power density of 100 µW cm-2 (126.6 W kg-1) for a symmetric two-electrode device. The device showed a good capacitance retention of 76% after 5000 cycles and was able to maintain 80% of its electrochemical properties while being measured at different bending angles, demonstrating excellent mechanical agility performance under extreme conditions and some of the highest carbon-based energy storage properties.

9.
Transbound Emerg Dis ; 69(4): e71-e81, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34331389

RESUMO

Dog-mediated rabies is responsible for approximately 60,000 human deaths annually worldwide. Although dog slaughter for human consumption and its potential risk for rabies transmission has been reported, mainly in some parts of Western Africa and South-East Asia, more information on this and factors that influence dog meat consumption is required for a better understanding from places like Ghana where the practice is common. We tested 144 brain tissues from apparently healthy dogs slaughtered for human consumption for the presence of rabies viruses using a Lyssavirus-specific real-Time RT-PCR. Positive samples were confirmed by virus genome sequencing. We also administered questionnaires to 541 dog owners from three regions in Ghana and evaluated factors that could influence dog meat consumption. We interacted with butchers and observed slaughtering and meat preparation procedures. Three out of 144 (2.1%) brain tissues from apparently healthy dogs tested positive for rabies virus RNA. Two of the viruses with complete genomes were distinct from one another, but both belonged to the Africa 2 lineage. The third virus with a partial genome fragment had high sequence identity to the other two and also belonged to the Africa 2 lineage. Almost half of the study participants practiced dog consumption [49% (265/541)]. Males were almost twice (cOR = 1.72, 95% CI (1.17-2.52), p-value = .006) as likely to consume dog meat compared to females. Likewise, the Frafra tribe from northern Ghana [cOR = 825.1, 95% CI (185.3-3672.9), p-value < .0001] and those with non-specific tribes [cOR = 47.05, 95% CI (10.18-217.41), p-value < .0001] presented with higher odds of dog consumption compared to Ewes. The butchers used bare hands in meat preparation. This study demonstrates the presence of rabies virus RNA in apparently healthy dogs slaughtered for human consumption in Ghana and suggests a potential risk for rabies transmission. Veterinary departments and local assemblies are recommended to monitor and regulate this practice.


Assuntos
Doenças do Cão , Vírus da Raiva , Raiva , Doenças dos Ovinos , Animais , Doenças do Cão/epidemiologia , Cães , Feminino , Gana/epidemiologia , Humanos , Masculino , Carne , RNA , Raiva/epidemiologia , Raiva/veterinária , Vírus da Raiva/genética , Ovinos
10.
Eur Neurol ; 85(2): 162-168, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34788771

RESUMO

The neurological and psychological manifestations of trauma, confinement, and terror became apparent throughout Europe as soldiers were evacuated from the trenches of the Western Front. The response in the UK evolved as a result of the experience of medical staff embedded with the troops in base hospitals and the philosophy of those treating returned soldiers in specialist establishment. There were widely disparate approaches to the management encompassing simple supportive care, a psychanalytic approach and radical electric shock therapy. The latter was partially driven by the Queen Square experience in the UK but was also concurrently widely pursued throughout Europe. With experience, care was increasingly undertaken close to the front lines using a philosophy of immediacy and expectation of recovery. Post-war analysis was startlingly unsympathetic, yet the experiences and management of shell shock have guided psychiatric and medical understanding of functional illness and post-traumatic stress over the subsequent century. In this historical review, we have sought to present features of the UK response to the neurological manifestations of trauma, the way in which these changed as the war proceeded and the political and medical response in the aftermath of war.


Assuntos
Distúrbios de Guerra , Neurologia , Transtornos de Estresse Pós-Traumáticos , Distúrbios de Guerra/história , História do Século XX , Humanos , Transtornos de Estresse Pós-Traumáticos/história , Transtornos de Estresse Pós-Traumáticos/psicologia , Transtornos de Estresse Pós-Traumáticos/terapia , Reino Unido , I Guerra Mundial
11.
Glob Chang Biol ; 28(5): 1903-1918, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34873797

RESUMO

The boreal forest represents the terrestrial biome most heavily affected by climate change. However, no consensus exists regarding the impacts of these changes on the growth of tree species therein. Moreover, assessments of young tree responses in metrics transposable to forest management remain scarce. Here, we assessed the impacts of climate change on black spruce (Picea mariana [Miller] BSP) and jack pine (Pinus banksiana Lambert) growth, two dominant tree species in boreal forests of North America. Starting with a retrospective analysis including data from 2591 black spruces and 890 jack pines, we forecasted trends in 30-year height growth at the transitions from closed to open boreal coniferous forests in Québec, Canada. We considered three variables: (1) height growth, rarely used, but better-reflecting site potential than other growth proxies, (2) climate normals corresponding to the growth period of each stem, and (3) site type (as a function of texture, stoniness, and drainage), which can modify the effects of climate on tree growth. We found a positive effect of vapor pressure deficit on the growth of both species, although the effect on black spruce leveled off. For black spruce, temperatures had a positive effect on the height at 30 years, which was attenuated when and where climatic conditions became drier. Conversely, drought had a positive effect on height under cold conditions and a negative effect under warm conditions. Spruce growth was also better on mesic than on rocky and sub-hydric sites. For portions of the study areas with projected future climate within the calibration range, median height-change varied from 10 to 31% for black spruce and from 5 to 31% for jack pine, depending on the period and climate scenario. As projected increases are relatively small, they may not be sufficient to compensate for potential increases in future disturbances like forest fires.


Assuntos
Picea , Pinus , Mudança Climática , Picea/fisiologia , Pinus/fisiologia , Estudos Retrospectivos , Taiga , Árvores
12.
Foods ; 10(12)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34945682

RESUMO

In the wake of continual foodborne disease outbreaks in recent years, it is critical to focus on strategies that protect public health and reduce the incidence of foodborne pathogens and spoilage microorganisms. Currently, there are limitations associated with conventional microbial control methods, such as the use of chemical preservatives and heat treatments. For example, such conventional treatments adversely impact the sensorial properties of food, resulting in undesirable organoleptic characteristics. Moreover, the growing consumer advocacy for safe and healthy food products, and the resultant paradigm shift toward clean labels, have caused an increased interest in natural and effective antimicrobial alternatives. For instance, natural antimicrobial elements synthesized by lactic acid bacteria (LAB) are generally inhibitory to pathogens and significantly impede the action of food spoilage organisms. Bacteriocins and other LAB metabolites have been commercially exploited for their antimicrobial properties and used in many applications in the dairy industry to prevent the growth of undesirable microorganisms. In this review, we summarized the natural antimicrobial compounds produced by LAB, with a specific focus on the mechanisms of action and applications for microbial food spoilage prevention and disease control. In addition, we provide support in the review for our recommendation for the application of LAB as a potential alternative antimicrobial strategy for addressing the challenges posed by antibiotic resistance among pathogens.

13.
Microorganisms ; 9(8)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34442859

RESUMO

The presence of methylmercury in aquatic environments and marine food sources is of global concern. The chemical reaction for the addition of a methyl group to inorganic mercury occurs in diverse bacterial taxonomic groups including the Gram-negative, sulfate-reducing Desulfovibrionaceae family that inhabit extreme aquatic environments. The availability of whole-genome sequence datasets for members of the Desulfovibrionaceae presents opportunities to understand the microbial mechanisms that contribute to methylmercury production in extreme aquatic environments. We have applied bioinformatics resources and developed visual analytics resources to categorize a collection of 719 putative universal stress protein (USP) sequences predicted from 93 genomes of Desulfovibrionaceae. We have focused our bioinformatics investigations on protein sequence analytics by developing interactive visualizations to categorize Desulfovibrionaceae universal stress proteins by protein domain composition and functionally important amino acids. We identified 651 Desulfovibrionaceae universal stress protein sequences, of which 488 sequences had only one USP domain and 163 had two USP domains. The 488 single USP domain sequences were further categorized into 340 sequences with ATP-binding motif and 148 sequences without ATP-binding motif. The 163 double USP domain sequences were categorized into (1) both USP domains with ATP-binding motif (3 sequences); (2) both USP domains without ATP-binding motif (138 sequences); and (3) one USP domain with ATP-binding motif (21 sequences). We developed visual analytics resources to facilitate the investigation of these categories of datasets in the presence or absence of the mercury-methylating gene pair (hgcAB). Future research could utilize these functional categories to investigate the participation of universal stress proteins in the bacterial cellular uptake of inorganic mercury and methylmercury production, especially in anaerobic aquatic environments.

14.
J Dairy Res ; 88(3): 357-365, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34425920

RESUMO

The aim of this review was to present various topics related to lactose intolerance with special attention given to the role of fermented foods and probiotics in alleviating gastrointestinal symptoms. Lactose intolerance is a common digestive problem in which the human body is unable to digest lactose, known as milk sugar. Lactose intolerance can either be hereditary or a consequence of intestinal diseases. Recent work has demonstrated that fermented dairy products and probiotics can modify the metabolic activities of colonic microbiota and may alleviate the symptoms of lactose intolerance. We suggest that, lactose free dairy products could be recommended as alternatives for the alleviation of lactose intolerance and for the promotion of human health and wellness.


Assuntos
Alimentos Fermentados , Intolerância à Lactose/terapia , Probióticos , Animais , Colo/microbiologia , Laticínios/análise , Microbioma Gastrointestinal/fisiologia , Humanos , Lactase/deficiência , Lactase/metabolismo , Lactose/análise , Lactose/metabolismo , Probióticos/uso terapêutico
15.
J Phys Chem A ; 125(34): 7588-7595, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34410718

RESUMO

Impressive progress has been made in the past decade in the study of technological applications of varied types of quantum systems. With industry giants like IBM laying down their roadmap for scalable quantum devices with more than 1000-qubits by the end of 2023, efficient validation techniques are also being developed for testing quantum processing on these devices. The characterization of a quantum state is done by experimental measurements through the process called quantum state tomography (QST) which scales exponentially with the size of the system. However, QST performed using incomplete measurements is aptly suited for characterizing these quantum technologies especially with the current nature of noisy intermediate-scale quantum (NISQ) devices where not all mean measurements are available with high fidelity. We, hereby, propose an alternative approach to QST for the complete reconstruction of the density matrix of a quantum system in a pure state for any number of qubits by applying the maximal entropy formalism on the pairwise combinations of the known mean measurements. This approach provides the best estimate of the target state when we know the complete set of observables, which is the case of convergence of the reconstructed density matrix to a pure state. Our goal is to provide a practical inference of a quantum system in a pure state that can find its applications in the field of quantum error mitigation on a real quantum computer that we intend to investigate further.

16.
mBio ; 12(3): e0017321, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34154415

RESUMO

Bacteria that colonize animals must overcome, or coexist, with the reactive oxygen species products of inflammation, a front-line defense of innate immunity. Among these is the neutrophilic oxidant bleach, hypochlorous acid (HOCl), a potent antimicrobial that plays a primary role in killing bacteria through nonspecific oxidation of proteins, lipids, and DNA. Here, we report that in response to increasing HOCl levels, Escherichia coli regulates biofilm production via activation of the diguanylate cyclase DgcZ. We identify the mechanism of DgcZ sensing of HOCl to be direct oxidation of its regulatory chemoreceptor zinc-binding (CZB) domain. Dissection of CZB signal transduction reveals that oxidation of the conserved zinc-binding cysteine controls CZB Zn2+ occupancy, which in turn regulates the catalysis of c-di-GMP by the associated GGDEF domain. We find DgcZ-dependent biofilm formation and HOCl sensing to be regulated in vivo by the conserved zinc-coordinating cysteine. Additionally, point mutants that mimic oxidized CZB states increase total biofilm. A survey of bacterial genomes reveals that many pathogenic bacteria that manipulate host inflammation as part of their colonization strategy possess CZB-regulated diguanylate cyclases and chemoreceptors. Our findings suggest that CZB domains are zinc-sensitive regulators that allow host-associated bacteria to perceive host inflammation through reactivity with HOCl. IMPORTANCE Immune cells are well equipped to eliminate invading bacteria, and one of their primary tools is the synthesis of bleach, hypochlorous acid (HOCl), the same chemical used as a household disinfectant. In this work, we present findings showing that many host-associated bacteria possess a bleach-sensing protein that allows them to adapt to the presence of this chemical in their environment. We find that the bacterium Escherichia coli responds to bleach by hunkering down and producing a sticky matrix known as biofilm, which helps it aggregate and adhere to surfaces. This behavior may play an important role in pathogenicity for E. coli and other bacteria, as it allows the bacteria to detect and adapt to the weapons of the host immune system.


Assuntos
Aderência Bacteriana/genética , Biofilmes/crescimento & desenvolvimento , GMP Cíclico/análogos & derivados , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Inflamação/genética , Transdução de Sinais , Bactérias/classificação , Bactérias/genética , Bactérias/imunologia , Bactérias/metabolismo , Aderência Bacteriana/imunologia , Biofilmes/efeitos dos fármacos , GMP Cíclico/genética , GMP Cíclico/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/imunologia , Escherichia coli/metabolismo , Proteínas de Escherichia coli/imunologia , Proteínas de Escherichia coli/metabolismo , Genoma Bacteriano , Ácido Hipocloroso/farmacologia , Inflamação/imunologia
17.
Front Plant Sci ; 12: 658880, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995456

RESUMO

We investigated whether stand species mixture can attenuate the vulnerability of eastern Canada's boreal forests to climate change and insect epidemics. For this, we focused on two dominant boreal species, black spruce [Picea mariana (Mill.) BSP] and trembling aspen (Populus tremuloides Michx.), in stands dominated by black spruce or trembling aspen ("pure stands"), and mixed stands (M) composed of both species within a 36 km2 study area in the Nord-du-Québec region. For each species in each stand composition type, we tested climate-growth relations and assessed the impacts on growth by recorded insect epidemics of a black spruce defoliator, the spruce budworm (SBW) [Choristoneura fumiferana (Clem.)], and a trembling aspen defoliator, the forest tent caterpillar (FTC; Malacosoma disstria Hübn.). We implemented linear models in a Bayesian framework to explain baseline and long-term trends in tree growth for each species according to stand composition type and to differentiate the influences of climate and insect epidemics on tree growth. Overall, we found climate vulnerability was lower for black spruce in mixed stands than in pure stands, while trembling aspen was less sensitive to climate than spruce, and aspen did not present differences in responses based on stand mixture. We did not find any reduction of vulnerability for mixed stands to insect epidemics in the host species, but the non-host species in mixed stands could respond positively to epidemics affecting the host species, thus contributing to stabilize ecosystem-scale growth over time. Our findings partially support boreal forest management strategies including stand species mixture to foster forests that are resilient to climate change and insect epidemics.

18.
Nat Commun ; 12(1): 2162, 2021 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-33846343

RESUMO

Diguanylate cyclases synthesising the bacterial second messenger c-di-GMP are found to be regulated by a variety of sensory input domains that control the activity of their catalytical GGDEF domain, but how activation proceeds mechanistically is, apart from a few examples, still largely unknown. As part of two-component systems, they are activated by cognate histidine kinases that phosphorylate their Rec input domains. DgcR from Leptospira biflexa is a constitutively dimeric prototype of this class of diguanylate cyclases. Full-length crystal structures reveal that BeF3- pseudo-phosphorylation induces a relative rotation of two rigid halves in the Rec domain. This is coupled to a reorganisation of the dimeric structure with concomitant switching of the coiled-coil linker to an alternative heptad register. Finally, the activated register allows the two substrate-loaded GGDEF domains, which are linked to the end of the coiled-coil via a localised hinge, to move into a catalytically competent dimeric arrangement. Bioinformatic analyses suggest that the binary register switch mechanism is utilised by many diguanylate cyclases with N-terminal coiled-coil linkers.


Assuntos
Proteínas de Escherichia coli/metabolismo , Leptospira/enzimologia , Fósforo-Oxigênio Liases/metabolismo , Regulação Alostérica , Sequência de Aminoácidos , Ácido Aspártico/metabolismo , Berílio/química , Ativação Enzimática , Proteínas de Escherichia coli/química , Retroalimentação Fisiológica , Fluoretos/química , Cinética , Modelos Moleculares , Fósforo-Oxigênio Liases/química , Fosforilação , Domínios Proteicos , Multimerização Proteica , Estrutura Secundária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Rotação
19.
Tob Prev Cessat ; 29: 29, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33928198

RESUMO

INTRODUCTION: The use of e-cigarettes has been the subject of a public health debate on their possibility of undermining efforts for tobacco control. The aim of this study was to synthesize the risk of smoking relapse with the use of e-cigarettes by former smokers. METHODS: MEDLINE, EMBASE, PsycInfo and LILACS were searched without restriction to language or date of publication. Longitudinal observational studies evaluating the association between e-cigarette use and smoking relapse were selected by two independent reviewers, and disagreements solved by discussion with a third researcher. Data extraction and risk of bias assessment were also carried out by two independent reviewers. The meta-analysis was performed using the random effect Mantel-Haenszel model. RESULTS: From 632 retrieved records, six studies were eligible and described, while three were included in the quantitative synthesis. The studies were conducted in the USA, UK and France, with final sample size varying from 374 to 4094 former smokers. Risk of relapse was 2.03 (95% CI: 1.39-2.96) among former smoker users than non-users of e-cigarettes, and 1.38 (95% CI: 1.11-1.65) when pooling the adjusted association measures. Long-term former smokers were the main contributors for the higher relapse risk, while the impact of frequency of exposure to e-cigarettes (past, non-daily, daily) was uncertain. CONCLUSIONS: Considering the growing popularity of e-cigarettes among former smokers, our results point to the great potential for an increase in the frequency of relapse to conventional smoking and vaping for those who move to regular use of e-cigarettes.

20.
Spine Deform ; 9(3): 697-702, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33580371

RESUMO

PURPOSE: While the Scoliosis Research Society (SRS) has established criteria for brace initiation in adolescent idiopathic scoliosis (AIS), there are no recommendations concerning other management issues. As the BrAIST study reinforced the utility of bracing, the SRS Non-Operative Management Committee decided to evaluate the consensus or discord in AIS brace management. METHODS: 1200 SRS members were sent an online survey in 2017, which included 21 items concerning demographics, bracing indications, management, and monitoring. Free-text responses were analyzed and collated into common themes. Data were analyzed using Microsoft Excel 2013. RESULTS: Of 218 respondents; 207 regularly evaluate and manage patients with AIS, and 205 currently prescribe bracing. 99% of respondents use bracing for AIS and the majority (89%) use the published SRS criteria, or a modified version, to initiate bracing. 85% do not use brace monitoring and 66% use both %-Cobb correction and fit criteria to evaluate brace adequacy. In contrast, other aspects of brace management demonstrated a high degree of practice variability. This was seen with a radiographic assessment of maturity level, hours prescribed, timing and frequency of radiographic evaluation, the use of nighttime bracing only, and the method and timing of brace discontinuation. CONCLUSION: Although there is consensus in brace management amongst SRS members with respect to brace initiation and evaluation of adequacy, there is striking variability in how bracing for AIS is used. This variability may impact the overall efficacy of brace treatment and may be decreased with more robust guidelines from the SRS. LEVEL OF EVIDENCE: III.


Assuntos
Cifose , Escoliose , Adolescente , Braquetes , Consenso , Humanos , Escoliose/diagnóstico por imagem , Escoliose/terapia , Sociedades
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