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1.
Nature ; 585(7824): 256-260, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848244

RESUMO

Temperature controls plant growth and development, and climate change has already altered the phenology of wild plants and crops1. However, the mechanisms by which plants sense temperature are not well understood. The evening complex is a major signalling hub and a core component of the plant circadian clock2,3. The evening complex acts as a temperature-responsive transcriptional repressor, providing rhythmicity and temperature responsiveness to growth through unknown mechanisms2,4-6. The evening complex consists of EARLY FLOWERING 3 (ELF3)4,7, a large scaffold protein and key component of temperature sensing; ELF4, a small α-helical protein; and LUX ARRYTHMO (LUX), a DNA-binding protein required to recruit the evening complex to transcriptional targets. ELF3 contains a polyglutamine (polyQ) repeat8-10, embedded within a predicted prion domain (PrD). Here we find that the length of the polyQ repeat correlates with thermal responsiveness. We show that ELF3 proteins in plants from hotter climates, with no detectable PrD, are active at high temperatures, and lack thermal responsiveness. The temperature sensitivity of ELF3 is also modulated by the levels of ELF4, indicating that ELF4 can stabilize the function of ELF3. In both Arabidopsis and a heterologous system, ELF3 fused with green fluorescent protein forms speckles within minutes in response to higher temperatures, in a PrD-dependent manner. A purified fragment encompassing the ELF3 PrD reversibly forms liquid droplets in response to increasing temperatures in vitro, indicating that these properties reflect a direct biophysical response conferred by the PrD. The ability of temperature to rapidly shift ELF3 between active and inactive states via phase transition represents a previously unknown thermosensory mechanism.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Priônicas/química , Temperatura , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Aclimatação/fisiologia , Arabidopsis/química , Temperatura Alta , Modelos Moleculares , Peptídeos/metabolismo , Transição de Fase , Domínios Proteicos , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo
2.
Nature ; 567(7747): 209-212, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30867609

RESUMO

Machine learning and quantum computing are two technologies that each have the potential to alter how computation is performed to address previously untenable problems. Kernel methods for machine learning are ubiquitous in pattern recognition, with support vector machines (SVMs) being the best known method for classification problems. However, there are limitations to the successful solution to such classification problems when the feature space becomes large, and the kernel functions become computationally expensive to estimate. A core element in the computational speed-ups enabled by quantum algorithms is the exploitation of an exponentially large quantum state space through controllable entanglement and interference. Here we propose and experimentally implement two quantum algorithms on a superconducting processor. A key component in both methods is the use of the quantum state space as feature space. The use of a quantum-enhanced feature space that is only efficiently accessible on a quantum computer provides a possible path to quantum advantage. The algorithms solve a problem of supervised learning: the construction of a classifier. One method, the quantum variational classifier, uses a variational quantum circuit1,2 to classify the data in a way similar to the method of conventional SVMs. The other method, a quantum kernel estimator, estimates the kernel function on the quantum computer and optimizes a classical SVM. The two methods provide tools for exploring the applications of noisy intermediate-scale quantum computers3 to machine learning.

3.
Nature ; 567(7749): 491-495, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30918370

RESUMO

Quantum computation, a paradigm of computing that is completely different from classical methods, benefits from theoretically proved speed-ups for certain problems and can be used to study the properties of quantum systems1. Yet, because of the inherently fragile nature of the physical computing elements (qubits), achieving quantum advantages over classical computation requires extremely low error rates for qubit operations, as well as substantial physical qubits, to realize fault tolerance via quantum error correction2,3. However, recent theoretical work4,5 has shown that the accuracy of computation (based on expectation values of quantum observables) can be enhanced through an extrapolation of results from a collection of experiments of varying noise. Here we demonstrate this error mitigation protocol on a superconducting quantum processor, enhancing its computational capability, with no additional hardware modifications. We apply the protocol to mitigate errors in canonical single- and two-qubit experiments and then extend its application to the variational optimization6-8 of Hamiltonians for quantum chemistry and magnetism9. We effectively demonstrate that the suppression of incoherent errors helps to achieve an otherwise inaccessible level of accuracy in the variational solutions using our noisy processor. These results demonstrate that error mitigation techniques will enable substantial improvements in the capabilities of near-term quantum computing hardware.

4.
Hippocampus ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39373314

RESUMO

The hippocampus (HC) is recognized for its pivotal role in memory-related plasticity and facilitating adaptive behavioral responses to reward shifts. However, the nature of its involvement in the response to reward downshifts remains to be determined. To bridge this knowledge gap, we explored the HC's function through a series of experiments in various tasks involving reward downshifts and using several neural manipulations in rats. In Experiment 1, complete excitotoxic lesions of the HC impaired choice performance in a modified T-maze after reducing the quantity of sugar pellet rewards. In Experiment 2, chemogenetic inhibition of the dorsal HC (dHC) disrupted anticipatory behavior following a food-pellet reward reduction. Experiments 3-5 impaired HC function by using peripheral lipopolysaccharide (LPS) administration. This treatment, which induces peripheral inflammation affecting HC function, significantly increased cytokine levels in the dHC (Experiment 3) and impaired anticipatory choice behavior (Experiment 4). None of these dorsal hippocampal manipulations affected consummatory responses in animals experiencing sucrose downshifts. Accordingly, we found no evidence of increased neural activation in either the dorsal or ventral HC, as measured by c-Fos expression, after a sucrose downshift task involving consummatory suppression (Experiment 6). The results highlight the HC's pivotal role in adaptively modulating anticipatory behavior in response to a variety of situations involving frustrative nonreward, while having no effect on adjustments on consummatory behavior. The data supporting this conclusion were obtained under heterogeneous experimental conditions derived from a multi-laboratory collaboration, ensuring the robustness and high reproducibility of our findings. Spatial orientation, memory update, choice of reward signals of different values, and anticipatory versus consummatory adjustments to reward downshift are discussed as potential mechanisms that could account for the specific effects observed from HC manipulations.

5.
Ann Surg ; 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38489660

RESUMO

OBJECTIVE: Assess factors affecting the cumulative lifespan of a transplanted liver. SUMMARY BACKGROUND DATA: Liver ageing is different from other solid organs. It is unknown how old a liver can actually get after liver transplantation (LT). METHODS: Deceased donor liver transplants from 1988-2021 were queried from the United States (US) UNOS registry. Cumulative liver age was calculated as donor age + recipient graft survival. RESULTS: In total, 184,515 livers were included. Most were DBD-donors (n=175,343). The percentage of livers achieving >70, 80, 90 and 100years cumulative age was 7.8% (n=14,392), 1.9% (n=3,576), 0.3% (n=528), and 0.01% (n=21), respectively. The youngest donor age contributing to a cumulative liver age >90years was 59years, with post-transplant survival of 34years. In pediatric recipients, 736 (4.4%) and 282 livers (1.7%) survived >50 and 60years overall, respectively. Transplanted livers achieved cumulative age >90years in 2.86-per-1000 and >100years in 0.1-per-1000. The US population at-large has a cumulative "liver age" >90years in 5.35-per-1000 persons, and >100y in 0.2-per-1000. Livers aged>60 years at transplant experienced both improved cumulative survival ( P <0.0001) and interestingly improved survival after transplantation ( P <0.0001). Recipient warm-ischemia-time of >30minutes was most predictive of reduced cumulative liver survival overall (n=184,515, HR=1.126, P <0.001) and excluding patients with mortality in the first 6month (n=151,884, HR=0.973, P <0.001). CONCLUSIONS: In summary, transplanted livers frequently get as old as those in the average population despite ischemic-reperfusion-injury and immunosuppression. The presented results justify using older donor livers regardless of donation type, even in sicker recipients with limited options.

6.
Ann Surg ; 280(2): 300-310, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38557793

RESUMO

OBJECTIVE: Assess cost and complication outcomes after liver transplantation (LT) using normothermic machine perfusion (NMP). BACKGROUND: End-ischemic NMP is often used to aid logistics, yet its impact on outcomes after LT remains unclear, as does its true impact on costs associated with transplantation. METHODS: Deceased donor liver recipients at 2 centers (January 1, 2019, to June 30, 2023) were included. Retransplants, splits, and combined grafts were excluded. End-ischemic NMP (OrganOx-Metra) was implemented in October 2022 for extended-criteria donation after brain death (DBDs), all donations after circulatory deaths (DCDs), and logistics. NMP cases were matched 1:2 with static cold storage controls (SCS) using the Balance-of-Risk [donation after brain death (DBD)-grafts] and UK-DCD Score (DCD-grafts). RESULTS: Overall, 803 transplantations were included, 174 (21.7%) receiving NMP. Matching was achieved between 118 NMP-DBDs with 236 SCS; and 37 NMP-DCD with 74 corresponding SCS. For both graft types, median inpatient comprehensive complications index values were comparable between groups. DCD-NMP grafts experienced reduced cumulative 90-day comprehensive complications index (27.6 vs 41.9, P =0.028). NMP also reduced the need for early relaparotomy and renal replacement therapy, with subsequently less frequent major complications (Clavien-Dindo ≥IVa). This effect was more pronounced in DCD transplants. NMP had no protective effect on early biliary complications. Organ acquisition/preservation costs were higher with NMP, yet NMP-treated grafts had lower 90-day pretransplant costs in the context of shorter waiting list times. Overall costs were comparable for both cohorts. CONCLUSIONS: This is the first risk-adjusted outcome and cost analysis comparing NMP and SCS. In addition to logistical benefits, NMP was associated with a reduction in relaparotomy and bleeding in DBD grafts, and overall complications and post-LT renal replacement for DCDs. While organ acquisition/preservation was more costly with NMP, overall 90-day health care costs-per-transplantation were comparable.


Assuntos
Transplante de Fígado , Preservação de Órgãos , Perfusão , Complicações Pós-Operatórias , Humanos , Masculino , Feminino , Transplante de Fígado/economia , Pessoa de Meia-Idade , Perfusão/métodos , Preservação de Órgãos/métodos , Preservação de Órgãos/economia , Complicações Pós-Operatórias/economia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Adulto , Idoso , Sobrevivência de Enxerto
7.
Ann Surg ; 279(1): 45-57, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37450702

RESUMO

OBJECTIVE: To develop and update evidence-based and consensus-based guidelines on laparoscopic and robotic pancreatic surgery. SUMMARY BACKGROUND DATA: Minimally invasive pancreatic surgery (MIPS), including laparoscopic and robotic surgery, is complex and technically demanding. Minimizing the risk for patients requires stringent, evidence-based guidelines. Since the International Miami Guidelines on MIPS in 2019, new developments and key publications have been reported, necessitating an update. METHODS: Evidence-based guidelines on 22 topics in 8 domains were proposed: terminology, indications, patients, procedures, surgical techniques and instrumentation, assessment tools, implementation and training, and artificial intelligence. The Brescia Internationally Validated European Guidelines on Minimally Invasive Pancreatic Surgery (EGUMIPS, September 2022) used the Scottish Intercollegiate Guidelines Network (SIGN) methodology to assess the evidence and develop guideline recommendations, the Delphi method to establish consensus on the recommendations among the Expert Committee, and the AGREE II-GRS tool for guideline quality assessment and external validation by a Validation Committee. RESULTS: Overall, 27 European experts, 6 international experts, 22 international Validation Committee members, 11 Jury Committee members, 18 Research Committee members, and 121 registered attendees of the 2-day meeting were involved in the development and validation of the guidelines. In total, 98 recommendations were developed, including 33 on laparoscopic, 34 on robotic, and 31 on general MIPS, covering 22 topics in 8 domains. Out of 98 recommendations, 97 reached at least 80% consensus among the experts and congress attendees, and all recommendations were externally validated by the Validation Committee. CONCLUSIONS: The EGUMIPS evidence-based guidelines on laparoscopic and robotic MIPS can be applied in current clinical practice to provide guidance to patients, surgeons, policy-makers, and medical societies.


Assuntos
Laparoscopia , Cirurgiões , Humanos , Inteligência Artificial , Pâncreas/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Laparoscopia/métodos
8.
Nat Methods ; 18(11): 1377-1385, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34711973

RESUMO

Liquid chromatography-high-resolution mass spectrometry (LC-MS)-based metabolomics aims to identify and quantify all metabolites, but most LC-MS peaks remain unidentified. Here we present a global network optimization approach, NetID, to annotate untargeted LC-MS metabolomics data. The approach aims to generate, for all experimentally observed ion peaks, annotations that match the measured masses, retention times and (when available) tandem mass spectrometry fragmentation patterns. Peaks are connected based on mass differences reflecting adduction, fragmentation, isotopes, or feasible biochemical transformations. Global optimization generates a single network linking most observed ion peaks, enhances peak assignment accuracy, and produces chemically informative peak-peak relationships, including for peaks lacking tandem mass spectrometry spectra. Applying this approach to yeast and mouse data, we identified five previously unrecognized metabolites (thiamine derivatives and N-glucosyl-taurine). Isotope tracer studies indicate active flux through these metabolites. Thus, NetID applies existing metabolomic knowledge and global optimization to substantially improve annotation coverage and accuracy in untargeted metabolomics datasets, facilitating metabolite discovery.


Assuntos
Algoritmos , Curadoria de Dados/normas , Fígado/metabolismo , Metaboloma , Metabolômica/normas , Saccharomyces cerevisiae/metabolismo , Animais , Cromatografia Líquida/métodos , Curadoria de Dados/métodos , Metabolômica/métodos , Camundongos , Espectrometria de Massas em Tandem/métodos
9.
Liver Transpl ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39311852

RESUMO

The comparison of outcomes in liver transplantation (LT) is hampered by using clinically non-relevant surrogate endpoints and considerable variability in reported relevant post-transplant outcomes. Such variability stems from non-standard outcome measures across studies, variable definitions of the same complication, and different timing of reporting. The Clavien-Dindo classification was established to improve the rigor of outcome reporting but is non-specific to an intervention and there are unsolved dilemmas specifically related to liver transplantation. Core Outcome Sets (COS) have been used in other specialties to standardize outcomes research, but have not been defined for LT. Thus, we use the five major benchmarking studies published to date to define a 10-measure COS for LT using previously validated metrics. We further provide standard definitions for each of the 10 measures that may be used in international research on the topic. These definitions also include standard time-points for recording to facilitate between-study comparisons and future meta-analysis. These 10 outcomes are paired with 3 validated, procedure-independent metrics, including the Clavien-Dindo Classification and the Comprehensive Complications Index (CCI®). The Clavien scale and CCI® are specifically reviewed to enhance their utility in LT, and their use along with the COS is explored. We encourage future studies to employ this COS along with the Clavien-Dindo grading system & CCI® to improve reproducibility and generalizability of research concerning liver transplantation.

10.
Neurobiol Learn Mem ; 213: 107942, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38815677

RESUMO

The amygdala has been implicated in frustrative nonreward induced by unexpected reward downshifts, using paradigms like consummatory successive negative contrast (cSNC). However, existing evidence comes from experiments involving the central and basolateral nuclei on a broad level. Moreover, whether the amygdala's involvement in reward downshift requires a cSNC effect (i.e., greater suppression in downshifted animals than in unshifted controls) or just consummatory suppression without a cSNC effect, remains unclear. Three groups were exposed to (1) a large reward disparity leading to a cSNC effect (32-to-2% sucrose), (2) a small reward disparity involving consummatory suppression in the absence of a cSNC effect (8-to-2% sucrose), and (3) an unshifted control (2% sucrose). Brains obtained after the first reward downshift session were processed for c-Fos expression, a protein often used as a marker for neural activation. c-Fos-positive cells were counted in the anterior, medial, and posterior portions (A/P axis) of ten regions of the rat basolateral, central, and medial amygdala. c-Fos expression was higher in 32-to-2% sucrose downshift animals than in the other two groups in four regions: the anterior and the medial lateral basal amygdala, the medial capsular central amygdala, and the anterior anterio-ventral medial amygdala. None of the areas exhibited differential c-Fos expression between the 8-to-2% sucrose downshift and the unshifted conditions. Thus, amygdala activation requires exposure to a substantial reward disparity. This approach has identified, for the first time, specific amygdala areas relevant to understand the cSNC effect, suggesting follow-up experiments aimed at testing the function of these regions in reward downshift.


Assuntos
Tonsila do Cerebelo , Proteínas Proto-Oncogênicas c-fos , Recompensa , Animais , Tonsila do Cerebelo/metabolismo , Tonsila do Cerebelo/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Masculino , Ratos , Ratos Wistar , Comportamento Consumatório/fisiologia
11.
Malar J ; 23(1): 126, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685081

RESUMO

INTRODUCTION: Introduction: Malaria continues to be the leading cause of hospitalization and death in Angola, a country in sub- Saharan Africa. In 2023, in the first quarter, 2,744,682 cases were registered, and of these 2,673 patients died due to malaria disease. Previous studies have shown that the ABO blood group can affect the progression of malaria to severe conditions after P. falciparum infection, while the sickle cell gene offers relative protection. OBJECTIVE: We investigated changes in the blood count according to blood groups (ABO/Rh) and sickle cell trait in patients with malaria in Luanda, capital of Angola. METHODOLOGY: This was a longitudinal, prospective and observational study with 198 patients hospitalized for malaria. RESULTS: Of the 198 patients studied, 13(6.6%) were ABRh(+), 4(2.0%) were ARh(-), 49(24.7%) were ARh(+), 42(21, 2%) were BRh (+), 5(2.5%) were ORh(-) and 85(42.9%) were ORh(+). For sickle cell trait, 145(73.2%) were AA, 37(18.7%) were AS and 16(8.1%) were SS. No statistical relationship was observed between age group, sex, parasitemia, clinical picture, hematocrit, MCV, HCM, MCHC, leukocytes, NEUT, LINF and PTL values with blood groups (p<0.05), but there was a relationship between values of hemoglobin and ABO/Rh blood groups (p>0.05). There was no relationship between age, parasitemia, clinical condition, MCV, HCM and MCHC values, leukocytes, NEUT and LINF with sickle cell trait (p<0.05), but there was a relationship between sex, hemoglobin and PTL and sickle cell values. sickle cell trait (p>0.05). CONCLUSION: It is imperative to differentiate patients with malaria based on blood groups and sickle cell trait, taking into account mainly the blood count parameters that demonstrate that there are patients who, depending on blood group or sickle cell trait, may react weakly to malaria infection regardless of the degree of parasitemia and medical prognosis.


Assuntos
Traço Falciforme , Humanos , Traço Falciforme/sangue , Masculino , Feminino , Estudos Prospectivos , Adulto , Criança , Adolescente , Pré-Escolar , Adulto Jovem , Estudos Longitudinais , Angola , Pessoa de Meia-Idade , Sistema ABO de Grupos Sanguíneos , Contagem de Células Sanguíneas/estatística & dados numéricos , Malária Falciparum/sangue , Sistema do Grupo Sanguíneo Rh-Hr , Lactente , Idoso
12.
Crit Care ; 28(1): 132, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649920

RESUMO

BACKGROUND: Rapidly improving acute respiratory distress syndrome (RIARDS) is an increasingly appreciated subgroup of ARDS in which hypoxemia improves within 24 h after initiation of mechanical ventilation. Detailed clinical and biological features of RIARDS have not been clearly defined, and it is unknown whether RIARDS is associated with the hypoinflammatory or hyperinflammatory phenotype of ARDS. The purpose of this study was to define the clinical and biological features of RIARDS and its association with inflammatory subphenotypes. METHODS: We analyzed data from 215 patients who met Berlin criteria for ARDS (endotracheally intubated) and were enrolled in a prospective observational cohort conducted at two sites, one tertiary care center and one urban safety net hospital. RIARDS was defined according to previous studies as improvement of hypoxemia defined as (i) PaO2:FiO2 > 300 or (ii) SpO2: FiO2 > 315 on the day following diagnosis of ARDS (day 2) or (iii) unassisted breathing by day 2 and for the next 48 h (defined as absence of endotracheal intubation on day 2 through day 4). Plasma biomarkers were measured on samples collected on the day of study enrollment, and ARDS phenotypes were allocated as previously described. RESULTS: RIARDS accounted for 21% of all ARDS participants. Patients with RIARDS had better clinical outcomes compared to those with persistent ARDS, with lower hospital mortality (13% vs. 57%; p value < 0.001) and more ICU-free days (median 24 vs. 0; p value < 0.001). Plasma levels of interleukin-6, interleukin-8, and plasminogen activator inhibitor-1 were significantly lower among patients with RIARDS. The hypoinflammatory phenotype of ARDS was more common among patients with RIARDS (78% vs. 51% in persistent ARDS; p value = 0.001). CONCLUSIONS: This study identifies a high prevalence of RIARDS in a multicenter observational cohort and confirms the more benign clinical course of these patients. We report the novel finding that RIARDS is characterized by lower concentrations of plasma biomarkers of inflammation compared to persistent ARDS, and that hypoinflammatory ARDS is more prevalent among patients with RIARDS. Identification and exclusion of RIARDS could potentially improve prognostic and predictive enrichment in clinical trials.


Assuntos
Biomarcadores , Respiração Artificial , Síndrome do Desconforto Respiratório , Humanos , Síndrome do Desconforto Respiratório/terapia , Síndrome do Desconforto Respiratório/sangue , Síndrome do Desconforto Respiratório/fisiopatologia , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Prospectivos , Idoso , Biomarcadores/sangue , Biomarcadores/análise , Respiração Artificial/métodos , Respiração Artificial/estatística & dados numéricos , Adulto , Estudos de Coortes , Hipóxia/sangue
13.
J Environ Manage ; 370: 122574, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39321675

RESUMO

Non-thermal plasma has been an emerging technology for water treatment for decades. In this study, we have designed and fabricated a bubbling plasma batch reactor using an atmospheric pressure dielectric barrier discharge with a hydrophobic porous membrane. The reactor performance is assessed for purifying synthetic contaminated water samples containing chemical contaminant sulfamethoxazole (SMX), a widely used antibiotic, and biological contaminant E. coli K12. The SMX decontamination tests indicate that the degradation process is not first-order and the reaction rate dwindle with increasing initial concentration. The yield at 50% removal achieves its highest value of 8.12 g/kWh for 50 mg/L SMX sample. For inactivation of E. coli K12 tests, the inactivation process is also not first-order, and the pathogen is completely inactivated for 102 CFU/mL and 104 CFU/mL cases after 10 min and 45 min of plasma treatment, respectively. For the 108 CFU/mL sample, a 5-log reduction is achieved after 60 min of treatment. The developed plasma reactor can achieve fast deployment in point of use, low cost for manufacturing, and simple for maintenance. Moreover, it can be used for in-situ water purification in future long duration crewed space missions as well as tackling with water pollution issues on our planet.

14.
J Biol Chem ; 298(10): 102397, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35988640

RESUMO

Sterols in eukaryotic cells play important roles in modulating membrane fluidity and in cell signaling and trafficking. During evolution, a combination of gene losses and acquisitions gave rise to an extraordinary diversity of sterols in different organisms. The sterol C-22 desaturase identified in plants and fungi as a cytochrome P-450 monooxygenase evolved from the first eukaryotic cytochrome P450 and was lost in many lineages. Although the ciliate Tetrahymena thermophila desaturates sterols at the C-22 position, no cytochrome P-450 orthologs are present in the genome. Here, we aim to identify the genes responsible for the desaturation as well as their probable origin. We used gene knockout and yeast heterologous expression approaches to identify two putative genes, retrieved from a previous transcriptomic analysis, as sterol C-22 desaturases. Furthermore, we demonstrate using bioinformatics and evolutionary analyses that both genes encode a novel type of sterol C-22 desaturase that belongs to the large fatty acid hydroxylase/desaturase superfamily and the genes originated by genetic duplication prior to functional diversification. These results stress the widespread existence of nonhomologous isofunctional enzymes among different lineages of the tree of life as well as the suitability for the use of T. thermophila as a valuable model to investigate the evolutionary process of large enzyme families.


Assuntos
Proteínas de Protozoários , Estearoil-CoA Dessaturase , Tetrahymena thermophila , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Saccharomyces cerevisiae , Estearoil-CoA Dessaturase/química , Estearoil-CoA Dessaturase/classificação , Estearoil-CoA Dessaturase/genética , Esteróis/metabolismo , Tetrahymena thermophila/enzimologia , Filogenia , Proteínas de Protozoários/química , Proteínas de Protozoários/classificação , Proteínas de Protozoários/genética
15.
Mol Microbiol ; 117(6): 1352-1365, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35484915

RESUMO

Lipoic acid (LA) is a sulfur-containing cofactor covalently attached to key enzymes of central metabolism in prokaryotes and eukaryotes. LA can be acquired by scavenging, mediated by a lipoate ligase, or de novo synthesized by a pathway requiring an octanoyltransferase and a lipoate synthase. A more complex pathway, referred to as "lipoyl-relay", requires two additional proteins, GcvH, the glycine cleavage system H subunit, and an amidotransferase. This route was described so far in Bacillus subtilis and related Gram-positive bacteria, Saccharomyces cerevisiae, Homo sapiens, and Caenorhabditis elegans. Using collections of S. cerevisiae and B. subtilis mutants, defective in LA metabolism, we gathered evidence that allows us to propose for the first time that lipoyl-relay pathways are also present in parasitic protozoa. By a reverse genetic approach, we assigned octanoyltransferase and amidotransferase activity to the products of Tb927.11.9390 (TblipT) and Tb927.8.630 (TblipL) genes of Trypanosoma brucei, respectively. The B. subtilis model allowed us to identify the parasite amidotransferase as the target of lipoate analogs like 8-bromo-octanoic acid, explaining the complete loss of protein lipoylation and growth impairment caused by this compound in T. cruzi. This model could be instrumental for the screening of selective and more efficient chemotherapies against trypanosomiases.


Assuntos
Redes e Vias Metabólicas , Ácido Tióctico , Trypanosoma brucei brucei , Bacillus subtilis/metabolismo , Ligases/metabolismo , Redes e Vias Metabólicas/genética , Saccharomyces cerevisiae/metabolismo , Ácido Tióctico/metabolismo , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismo
16.
Ann Surg ; 277(5): 821-828, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35946822

RESUMO

OBJECTIVE: To reach global expert consensus on the definition of TOLS in minimally invasive and open liver resection among renowned international expert liver surgeons using a modified Delphi method. BACKGROUND: Textbook outcome is a novel composite measure combining the most desirable postoperative outcomes into one single measure and representing the ideal postoperative course. Despite a recently developed international definition of Textbook Outcome in Liver Surgery (TOLS), a standardized and expert consensus-based definition is lacking. METHODS: This international, consensus-based, qualitative study used a Delphi process to achieve consensus on the definition of TOLS. The survey comprised 6 surgical domains with a total of 26 questions on individual surgical outcome variables. The process included 4 rounds of online questionnaires. Consensus was achieved when a threshold of at least 80% agreement was reached. The results from the Delphi rounds were used to establish an international definition of TOLS. RESULTS: In total, 44 expert liver surgeons from 22 countries and all 3 major international hepato-pancreato-biliary associations completed round 1. Forty-two (96%), 41 (98%), and 41 (98%) of the experts participated in round 2, 3, and 4, respectively. The TOLS definition derived from the consensus process included the absence of intraoperative grade ≥2 incidents, postoperative bile leakage grade B/C, postoperative liver failure grade B/C, 90-day major postoperative complications, 90-day readmission due to surgery-related major complications, 90-day/in-hospital mortality, and the presence of R0 resection margin. CONCLUSIONS: This is the first study providing an international expert consensus-based definition of TOLS for minimally invasive and open liver resections by the use of a formal Delphi consensus approach. TOLS may be useful in assessing patient-level hospital performance and carrying out international comparisons between centers with different clinical practices to further improve patient outcomes.


Assuntos
Fígado , Complicações Pós-Operatórias , Humanos , Técnica Delphi , Consenso , Complicações Pós-Operatórias/epidemiologia , Inquéritos e Questionários , Fígado/cirurgia
17.
Clin Transplant ; 37(8): e15045, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37306944

RESUMO

The advent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in China at the end of 2019 has developed into a global outbreak, and COVID- 19 is an ongoing major public health issue. During the pandemic, transplant programs had to devise strategies to deal with the possibility of COVID-19-positive donors and recipients. We describe the case of a heart transplant recipient who tested positive with the SARS- CoV2 swab upon admission to our Unit of Cardiac Surgery when a suitable donor became available. Given his clinical status of end-stage heart failure and the absence of imaging and clinical signs suggestive of COVID-19, and his having been vaccinated with three doses, we decided to proceed with the transplant.


Assuntos
COVID-19 , Transplante de Coração , Humanos , SARS-CoV-2 , Doadores de Tecidos , China , Transplantados
18.
Microb Cell Fact ; 22(1): 246, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38053171

RESUMO

Biodiesel, unlike to its fossil-based homologue (diesel), is renewable. Its use contributes to greater sustainability in the energy sector, mainly by reducing greenhouse gas emissions. Current biodiesel production relies on plant- and animal-related feedstocks, resulting in high final costs to the prices of those raw materials. In addition, the production of those materials competes for arable land and has provoked a heated debate involving their use food vs. fuel. As an alternative, single-cell oils (SCOs) obtained from oleaginous microorganisms are attractive sources as a biofuel precursor due to their high lipid content, and composition similar to vegetable oils and animal fats. To make SCOs competitive from an economic point of view, the use of readily available low-cost substrates becomes essential. This work reviews the most recent advances in microbial oil production from non-synthetic sugar-rich media, particularly sugars from lignocellulosic wastes, highlighting the main challenges and prospects for deploying this technology fully in the framework of a Biorefinery concept.


Assuntos
Biocombustíveis , Saccharomyces cerevisiae , Óleos de Plantas
19.
Crit Care ; 27(1): 234, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37312169

RESUMO

Angiopoietin-2 (Ang-2) is associated with vascular endothelial injury and permeability in the acute respiratory distress syndrome (ARDS) and sepsis. Elevated circulating Ang-2 levels may identify critically ill patients with distinct pathobiology amenable to targeted therapy. We hypothesized that plasma Ang-2 measured shortly after hospitalization among patients with sepsis would be associated with the development of ARDS and poor clinical outcomes. To test this hypothesis, we measured plasma Ang-2 in a cohort of 757 patients with sepsis, including 267 with ARDS, enrolled in the emergency department or early in their ICU course before the COVID-19 pandemic. Multivariable models were used to test the association of Ang-2 with the development of ARDS and 30-day morality. We found that early plasma Ang-2 in sepsis was associated with higher baseline severity of illness, the development of ARDS, and mortality risk. The association between Ang-2 and mortality was strongest among patients with ARDS and sepsis as compared to those with sepsis alone (OR 1.81 vs. 1.52 per log Ang-2 increase). These findings might inform models testing patient risk prediction and strengthen the evidence for Ang-2 as an appealing biomarker for patient selection for novel therapeutic agents to target vascular injury in sepsis and ARDS.


Assuntos
COVID-19 , Síndrome do Desconforto Respiratório , Sepse , Humanos , Angiopoietina-2 , Estado Terminal , Pandemias , Prognóstico
20.
Appl Opt ; 62(8): C122-C127, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-37133067

RESUMO

Multilayer graphene (MLG) thin films were produced by a sputtering technique on a cobalt buffer-layer prepared at 500°C and thermal annealed after the deposition. The transformation of amorphous carbon (C) to graphene occurs by diffusion of C atoms through the catalyst metal; then the C atoms dissolved in the metal are nucleated as graphene. The thicknesses of cobalt and MLG thin films were 55 and 54 nm, respectively, obtained by atomic force microscopy (AFM). Raman spectroscopy showed that the ratio between the Raman bands 2D and G (I 2D /I G ) was 0.4 for the graphene thin film that was annealed at 750°C for 25 min, indicating that the films obtained are MLG. The Raman results were corroborated by transmission electron microscopy analysis. AFM was used to determine the Co and C film thickness and roughness. Transmittance measurements at 980 nm as a function of input power from a continuous-wave diode laser showed that the obtained MLG films present large nonlinear absorption and can be used as optical limiters.

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