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1.
Nature ; 620(7975): 813-823, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37558877

RESUMO

Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature's diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature's values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a 'values crisis' underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature's diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures.


Assuntos
Ecossistema , Justiça Ambiental , Política Ambiental , Objetivos , Desenvolvimento Sustentável , Humanos , Biodiversidade , Desenvolvimento Sustentável/economia , Política Ambiental/economia , Mudança Climática
2.
Gastroenterology ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38795735

RESUMO

BACKGROUND & AIMS: Endoscopic mucosal resection (EMR) is standard therapy for nonpedunculated colorectal polyps ≥20 mm. It has been suggested recently that polyp resection without current (cold resection) may be superior to the standard technique using cutting/coagulation current (hot resection) by reducing adverse events (AEs), but evidence from a randomized trial is missing. METHODS: In this randomized controlled multicentric trial involving 19 centers, nonpedunculated colorectal polyps ≥20 mm were randomly assigned to cold or hot EMR. The primary outcome was major AE (eg, perforation or postendoscopic bleeding). Among secondary outcomes, major AE subcategories, postpolypectomy syndrome, and residual adenoma were most relevant. RESULTS: Between 2021 and 2023, there were 396 polyps in 363 patients (48.2% were female) enrolled for the intention-to-treat analysis. Major AEs occurred in 1.0% of the cold group and in 7.9% of the hot group (P = .001; odds ratio [OR], 0.12; 95% CI, 0.03-0.54). Rates for perforation and postendoscopic bleeding were significantly lower in the cold group, with 0% vs 3.9% (P = .007) and 1.0% vs 4.4% (P = .040). Postpolypectomy syndrome occurred with similar frequency (3.1% vs 4.4%; P = .490). After cold resection, residual adenoma was found more frequently, with 23.7% vs 13.8% (P = .020; OR, 1.94; 95% CI, 1.12-3.38). In multivariable analysis, lesion diameter of ≥4 cm was an independent predictor for major AEs (OR, 3.37) and residual adenoma (OR, 2.47) and for high-grade dysplasia/cancer for residual adenoma (OR, 2.92). CONCLUSIONS: Cold resection of large, nonpedunculated colorectal polyps appears to be considerably safer than hot EMR; however, at the cost of a higher residual adenoma rate. Further studies have to confirm to what extent polyp size and histology can determine an individualized approach. German Clinical Trials Registry (Deutsches Register Klinischer Studien), Number DRKS00025170.

3.
Proc Natl Acad Sci U S A ; 119(34): e2204510119, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35969781

RESUMO

Lytic polysaccharide monooxygenases (LPMOs) catalyze oxidative cleavage of crystalline polysaccharides such as cellulose and chitin and are important for biomass conversion in the biosphere as well as in biorefineries. The target polysaccharides of LPMOs naturally occur in copolymeric structures such as plant cell walls and insect cuticles that are rich in phenolic compounds, which contribute rigidity and stiffness to these materials. Since these phenolics may be photoactive and since LPMO action depends on reducing equivalents, we hypothesized that LPMOs may enable light-driven biomass conversion. Here, we show that redox compounds naturally present in shed insect exoskeletons enable harvesting of light energy to drive LPMO reactions and thus biomass conversion. The primary underlying mechanism is that irradiation of exoskeletons with visible light leads to the generation of H2O2, which fuels LPMO peroxygenase reactions. Experiments with a cellulose model substrate show that the impact of light depends on both light and exoskeleton dosage and that light-driven LPMO activity is inhibited by a competing H2O2-consuming enzyme. Degradation experiments with the chitin-rich exoskeletons themselves show that solubilization of chitin by a chitin-active LPMO is promoted by light. The fact that LPMO reactions, and likely reactions catalyzed by other biomass-converting redox enzymes, are fueled by light-driven abiotic reactions in nature provides an enzyme-based explanation for the known impact of visible light on biomass conversion.


Assuntos
Peróxido de Hidrogênio , Oxigenases de Função Mista , Exoesqueleto , Animais , Biomassa , Catálise , Celulose/metabolismo , Quitina/metabolismo , Peróxido de Hidrogênio/metabolismo , Insetos , Luz , Oxigenases de Função Mista/metabolismo , Polissacarídeos/metabolismo
4.
Solid State Nucl Magn Reson ; 132: 101936, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38823152

RESUMO

A recently developed dynamic mean-field theory for disordered spins (spinDMFT) is shown to capture the spin dynamics of nuclear spins very well. The key quantities are the spin autocorrelations. In order to compute the free induction decay (FID), pair correlations are needed in addition. They can be computed on spin clusters of moderate size which are coupled to the dynamic mean fields determined in a first step by spinDMFT. We dub this versatile approach non-local spinDMFT (nl-spinDMFT). It is a particular asset of nl-spinDMFT that one knows from where the contributions to the FID stem. We illustrate the strengths of nl-spinDMFT in comparison to experimental data for CaF2. Furthermore, spinDMFT provides the dynamic mean fields explaining the FID of the nuclear spins of 13C in adamantane up to some static noise. The spin Hahn echo in adamantane is free from effects of static noise and agrees excellently with the spinDMFT results without further fitting.

5.
Liver Int ; 43(10): 2116-2129, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37366005

RESUMO

BACKGROUND: Human pluripotent stem cell (hPSC)-derived hepatocyte-like cells (HLCs) are a valuable model to investigate host-pathogen interactions of hepatitis viruses in a mature and authentic environment. Here, we investigate the susceptibility of HLCs to the hepatitis delta virus (HDV). METHODS: We differentiated hPSC into HLCs, and inoculated them with infectious HDV produced in Huh7NTCP . HDV infection and cellular response was monitored by RTqPCR and immunostaining. RESULTS: Cells undergoing hepatic differentiation become susceptible to HDV after acquiring expression of the viral receptor Na+ -taurocholate co-transporting polypeptide (NTCP) during hepatic specification. Inoculation of HLCs with HDV leads to detection of intracellular HDV RNA and accumulation of the HDV antigen in the cells. Upon infection, the HLCs mounted an innate immune response based on induction of the interferons IFNB and L, and upregulation of interferon-stimulated genes. The intensity of this immune response positively correlated with the level of viral replication and was dependant on both the JAK/STAT and NFκB pathway activation. Importantly, this innate immune response did not inhibit HDV replication. However, pre-treatment of the HLCs with IFNα2b reduced viral infection, suggesting that ISGs may limit early stages of infection. Myrcludex efficiently abrogated infection and blocked innate immune activation. Lonafarnib treatment of HDV mono infected HLCs on the other hand led to exacerbated viral replication and innate immune response. CONCLUSION: The HDV in vitro mono-infection model represents a new tool to study HDV replication, its host-pathogen interactions and evaluate new antiviral drugs in cells displaying mature hepatic functions.


Assuntos
Hepatite D , Vírus Delta da Hepatite , Humanos , Vírus Delta da Hepatite/genética , Antivirais/farmacologia , Antivirais/uso terapêutico , Hepatite D/tratamento farmacológico , Hepatócitos/metabolismo , Imunidade Inata , Interferons/uso terapêutico , Células-Tronco , Replicação Viral , Vírus da Hepatite B/genética
6.
Surg Endosc ; 37(4): 2574-2586, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36344898

RESUMO

BACKGROUND AND AIMS: As there is still no consensus about the adequate training strategy for ESD in Western countries, we evaluated unsupervised prevalence-based learning curves including detailed organ-specific subgroup analysis. METHODS: The first 120 ESDs of four operators (n = 480) were divided into three groups (1: ESD 1-40, 2: ESD 41-80, 3: ESD 81-120). Outcome parameters were rates of technical success, en bloc and R0 resection, the resection speed, rates of conversion to EMR, curative resection, adverse events, surgery due to adverse events, and recurrence. In addition, we analyzed the achievement of quality benchmarks indicating levels of expertise. RESULTS: After exclusion of pretreated lesions, 438 procedures were enrolled in the final analysis. Technical success rates were > 96% with significant improvements regarding rate of en bloc resection (from 82.6 to 91.2%), resection speed (from 4.54 to 7.63 cm2/h), and rate of conversion to EMR (from 22.0 to 8.1%). No significant differences could be observed for rates of R0 resection (65.9 vs. 69.6%), curative resection (55.8 vs. 55.7%), adverse events (16.3 vs. 11.7%), surgery due to adverse events (1.5 vs. 1.3%), and recurrence (12.5 vs. 4.5%). Subgroup and benchmark analysis revealed an improvement in esophageal, gastric, and rectal ESD with achievement of competence levels for the esophagus and stomach within 80 and most of the benchmarks for proficiency level within 120 procedures. Some of the benchmarks could also be achieved in rectal ESD. CONCLUSIONS: This trial confirms safety and feasibility of unsupervised ESD along the initial learning curve with prevalence-based indication and exclusion of colonic cases.


Assuntos
Ressecção Endoscópica de Mucosa , Humanos , Ressecção Endoscópica de Mucosa/educação , Curva de Aprendizado , Prevalência , Mucosa Gástrica/cirurgia , Estômago
7.
Surg Endosc ; 37(6): 4370-4380, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36759355

RESUMO

BACKGROUND: Iatrogenic colorectal perforation is a rare event with a relevant mortality and the need for surgical therapy in around ¾ of cases. METHODS: In this retrospective multicentric cohort study iatrogenic colorectal perforations from 2004 to 2021 were analyzed. Primary outcome parameters were incidence and clinical success of 1st line endoscopic treatment. Comparative analysis of interventional and non-interventional perforations was performed and predictors for clinical success of endoscopic therapy were identified. RESULTS: From 103,570 colonoscopies 213 (0.2%) iatrogenic perforations were identified. 68.4% were interventional (80 during polypectomy/EMR, 54 during ESD and 11 for other reasons) and 31.6% non-interventional perforations (39 by the tip, 19 by the shaft, 7 by inversion, two by biopsy and one by distension). Incidence of 1st line endoscopic therapy was 61.0% and clinical success 81.5%. Other non-surgical therapies were conducted in 8.9% with clinical success in 94.7% of cases. In interventional perforations both incidence and clinical success of 1st line endoscopic therapy were significantly higher compared to non-interventional perforations [71.7% vs. 38.2% (p < 0.01) resp. 86.5% vs. 61.5% (p < 0.01)]. Mortality was 2.3% and significantly lower in the group of interventional perforations (0.7% vs. 5.9%, p = 0.037). Multivariable analysis revealed perforation size < 5 mm as only independent predictor for clinical success of 1st line endoscopic treatment [OR 14.85 (1.57-140.69), p = 0.019]. CONCLUSIONS: Endoscopic therapy is treatment of choice in the majority of iatrogenic colorectal perforations. In case of interventional perforations it is highly effective but only a minority of non-interventional perforations are good candidates for endoscopic treatment.


Assuntos
Neoplasias Colorretais , Perfuração Intestinal , Humanos , Estudos Retrospectivos , Estudos de Coortes , Resultado do Tratamento , Colonoscopia/efeitos adversos , Neoplasias Colorretais/patologia , Doença Iatrogênica , Perfuração Intestinal/etiologia , Perfuração Intestinal/cirurgia , Perfuração Intestinal/epidemiologia
8.
Dig Dis Sci ; 68(9): 3614-3624, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37421512

RESUMO

BACKGROUND: For an adequate educational strategy of ESD in non-Asian settings with prevalence-based indication it is essential to define adequate lesions, suitable for the beginner without on-site expert-supervision. AIMS: We analyzed possible predictors for outcome parameters of effectiveness and safety during the initial learning curve. METHODS: The first 120 ESDs of four operators (n = 480), performed between 2007 and 2020 in four tertiary hospitals, were enrolled. Uni-/multivariable regression analysis was done with sex, age, pretreated lesion, lesion size, organ, and organ-based localization as possible independent predictors for en bloc resection (EBR), complication, and resection speed. RESULTS: Rates of EBR, complication, and resection speed were 84.5%, 14.2%, and 6.20 (± 4.45) cm2/h. Independent predictors for EBR were pretreated lesion (OR 0.27 [0.13-0.57], p < 0.001) and non-colonic ESD (OR 2.29 [1.26-4.17] (rectum)/5.72 [2.36-13.89] (stomach)/7.80 [2.60-23.42] (esophagus), p < 0.001), for complication pretreated lesion (OR 3.04 [1.46-6.34], p < 0.001) and lesion size (OR 1.02 [1.004-1.04], p = 0.012) and for resection speed pretreated lesion (RC - 3.10 [- 4.39 to - 1.81], p < 0.001), lesion size (RC 0.13 [0.11-0.16], p < 0.001) and male patient (RC - 1.11 [- 1.85 to - 0.37], p < 0.001). We found no significant difference in the incidence of technically unsuccessful resections in esophageal (1/84), gastric (3/113), rectal (7/181), and colonic (3/101) ESDs (p = 0.76). Technical failure was mainly caused by complication and fibrosis/pretreatment. CONCLUSION: During the initial learning curve of an unsupervised ESD program with prevalence-based indication, pretreated lesions and colonic ESDs should be avoided. In contrast, lesion size and organ-based localizations have less predictive value for the outcome.


Assuntos
Ressecção Endoscópica de Mucosa , Humanos , Masculino , Ressecção Endoscópica de Mucosa/efeitos adversos , Curva de Aprendizado , Prevalência , Resultado do Tratamento , Colo , Estudos Retrospectivos
9.
Mar Drugs ; 21(1)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36662221

RESUMO

Microwave-assisted extraction (MAE) is recognized as a green method for extraction of natural products. The current research aimed to explore the MAE for fucoidans extraction from different brown seaweeds, including Fucus vesiculosus, F. spiralis, and Laminaria saccharina. Following several solvent-extraction pre-treatment steps and MAE optimization, the algal biomasses were extracted in a ratio of 1:25 in 0.1 M HCl containing 2 M CaCl2 for 1.0 min. The results showed that L. saccharina's extract was different from the others, regarding the highest sugar content reached 0.47 mg glucose equivalent/mg extract being confirmed by monosaccharide composition analysis and the lowest fucoidan content and sulfation degree at 0.09 mg/mg extract and 0.13, respectively. Moreover, these findings were confirmed by tentative structural elucidation based on Fourier-transform infrared spectrometry which also showed a different spectrum. However, the MAE enhanced melanoidins formation in products, which was confirmed by the intense band at 1420 cm-1. Interestingly, the results of monomeric composition showed that fucoidan extract by MAE from F. vesiculosus belonged to sulfated galactofucans which are known for their potential bioactivities. Furthermore, the cytotoxic activity of the four fucoidans in concentrations ranging from 4.9 µg/mL to 2500 µg/mL was investigated and correlated with the chemical characterization showing that F. vesiculosus_MAE fucoidan was the most potent and safest. The current research revealed the chemical heterogeneity of fucoidans regarding taxonomical class and used greener extraction method of fucoidans toward the achievement of the UN sustainability goals.


Assuntos
Antineoplásicos , Fucus , Phaeophyceae , Alga Marinha , Micro-Ondas , Polissacarídeos/farmacologia , Polissacarídeos/química , Alga Marinha/química , Phaeophyceae/química , Fucus/química
10.
J Proteome Res ; 20(8): 4041-4052, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34191517

RESUMO

Chitin is an abundant natural polysaccharide that is hard to degrade because of its crystalline nature and because it is embedded in robust co-polymeric materials containing other polysaccharides, proteins, and minerals. Thus, it is of interest to study the enzymatic machineries of specialized microbes found in chitin-rich environments. We describe a genomic and proteomic analysis of Andreprevotia ripae, a chitinolytic Gram-negative bacterium isolated from an anthill. The genome of A. ripae encodes four secreted family GH19 chitinases of which two were detected and upregulated during growth on chitin. In addition, the genome encodes as many as 25 secreted GH18 chitinases, of which 17 were detected and 12 were upregulated during growth on chitin. Finally, the single lytic polysaccharide monooxygenase (LPMO) was strongly upregulated during growth on chitin. Whereas 66% of the 29 secreted chitinases contained two carbohydrate-binding modules (CBMs), this fraction was 93% (13 out of 14) for the upregulated chitinases, suggesting an important role for these CBMs. Next to an unprecedented multiplicity of upregulated chitinases, this study reveals several chitin-induced proteins that contain chitin-binding CBMs but lack a known catalytic function. These proteins are interesting targets for discovery of enzymes used by nature to convert chitin-rich biomass. The MS proteomic data have been deposited in the PRIDE database with accession number PXD025087.


Assuntos
Betaproteobacteria/enzimologia , Quitinases , Proteômica , Animais , Formigas/microbiologia , Proteínas de Bactérias/genética , Betaproteobacteria/isolamento & purificação , Quitina , Quitinases/genética , Oxigenases de Função Mista/genética , Polissacarídeos
11.
J Exp Biol ; 224(20)2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34553762

RESUMO

Vertebrates confronted with challenging environments often experience an increase in circulating glucocorticoids, which result in morphological, physiological and behavioral changes that promote survival. However, chronically elevated glucocorticoids can suppress immunity, which may increase susceptibility to disease. Since the introduction of avian malaria to Hawaii a century ago, low-elevation populations of Hawaii Amakihi (Chlorodrepanis virens) have undergone strong selection by avian malaria and evolved increased resilience (the ability to recover from infection), while populations at high elevation with few vectors have not undergone selection and remain susceptible. We investigated how experimentally elevated corticosterone affects the ability of high- and low-elevation male Amakihi to cope with avian malaria by measuring innate immunity, hematocrit and malaria parasitemia. Corticosterone implants resulted in a decrease in hematocrit in high- and low-elevation birds but no changes to circulating natural antibodies or leukocytes. Overall, leukocyte count was higher in low- than in high-elevation birds. Malaria infections were detected in a subset of low-elevation birds. Infected individuals with corticosterone implants experienced a significant increase in circulating malaria parasites while untreated infected birds did not. Our results suggest that Amakihi innate immunity measured by natural antibodies and leukocytes is not sensitive to changes in corticosterone, and that high circulating corticosterone may reduce the ability of Amakihi to cope with infection via its effects on hematocrit and malaria parasite load. Understanding how glucocorticoids influence a host's ability to cope with introduced diseases provides new insight into the conservation of animals threatened by novel pathogens.


Assuntos
Malária Aviária , Passeriformes , Plasmodium , Animais , Corticosterona , Havaí , Humanos , Imunidade Inata , Masculino
12.
Gen Comp Endocrinol ; 308: 113784, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33862049

RESUMO

Glucocorticoids, androgens, and prolactin regulate metabolism and reproduction, but they also play critical roles in immunomodulation. Since the introduction of avian malaria to Hawaii a century ago, low elevation populations of the Hawaii Amakihi (Chlorodrepanis virens) that have experienced strong selection by avian malaria have evolved increased resilience (the ability to recover from infection), while high elevation populations that have undergone weak selection remain less resilient. We investigated how variation in malaria selection has affected corticosterone, testosterone, and prolactin hormone levels in Amakihi during the breeding season. We predicted that baseline corticosterone and testosterone (which have immunosuppressive functions) would be reduced in low elevation and malaria-infected birds, while stress-induced corticosterone and prolactin (which have immunostimulatory functions) would be greater in low elevation and malaria-infected birds. As predicted, prolactin was significantly higher in malaria-infected than uninfected females (although more robust sample sizes would help to confirm this relationship), while testosterone trended higher in malaria-infected than uninfected males and, surprisingly, neither baseline nor stress-induced CORT varied with malaria infection. Contrary to our predictions, stress-induced corticosterone was significantly lower in low than high elevation birds while testosterone in males and prolactin in females did not vary by elevation, suggesting that Amakihi hormone modulation across elevation is determined by variables other than disease selection (e.g., timing of breeding, energetic challenges). Our results shed new light on relationships between introduced disease and hormone modulation, and they raise new questions that could be explored in experimental settings.


Assuntos
Malária Aviária , Aves Canoras , Animais , Corticosterona , Feminino , Havaí , Masculino , Prolactina , Testosterona
13.
Artigo em Inglês | MEDLINE | ID: mdl-32513799

RESUMO

Several cationic amphiphilic drugs (CADs) have been found to inhibit cell entry of filoviruses and other enveloped viruses. Structurally unrelated CADs may have antiviral activity, yet the underlying common mechanism and structure-activity relationship are incompletely understood. We aimed to understand how widespread antiviral activity is among CADs and which structural and physico-chemical properties are linked to entry inhibition. We measured inhibition of Marburg virus pseudoparticle (MARVpp) cell entry by 45 heterogeneous and mostly FDA-approved CADs and cytotoxicity in EA.hy926 cells. We analyzed correlation of antiviral activity with four chemical properties: pKa, hydrophobicity (octanol/water partitioning coefficient; ClogP), molecular weight, and distance between the basic group and hydrophobic ring structures. Additionally, we quantified drug-induced phospholipidosis (DIPL) of a CAD subset by flow cytometry. Structurally similar compounds (derivatives) and those with similar chemical properties but unrelated structures (analogues) to those of strong inhibitors were obtained by two in silico similarity search approaches and tested for antiviral activity. Overall, 11 out of 45 (24%) CADs inhibited MARVpp by 40% or more. The strongest antiviral compounds were dronedarone, triparanol, and quinacrine. Structure-activity relationship studies revealed highly significant correlations between antiviral activity, hydrophobicity (ClogP > 4), and DIPL. Moreover, pKa and intramolecular distance between hydrophobic and hydrophilic moieties correlated with antiviral activity but to a lesser extent. We also showed that in contrast to analogues, derivatives had antiviral activity similar to that of the seed compound dronedarone. Overall, one-quarter of CADs inhibit MARVpp entry in vitro, and antiviral activity of CADs mostly relies on their hydrophobicity yet is promoted by the individual structure.


Assuntos
Filoviridae , Marburgvirus , Preparações Farmacêuticas , Antivirais/farmacologia , Internalização do Vírus
14.
Proc Biol Sci ; 287(1929): 20192993, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32576107

RESUMO

Historically, investigations of how organismal investments in immunity fluctuate in response to environmental and physiological changes have focused on seasonally breeding organisms that confine reproduction to seasons with relatively unchallenging environmental conditions and abundant resources. The red crossbill, Loxia curvirostra, is a songbird that can breed opportunistically if conifer seeds are abundant, on both short, cold, and long, warm days, providing an ideal system to investigate environmental and reproductive effects on immunity. In this study, we measured inter- and intra-annual variation in complement, natural antibodies, PIT54 and leucocytes in crossbills across four summers (2010-2013) and multiple seasons within 1 year (summer 2011-spring 2012). Overall, we observed substantial changes in crossbill immune investment among summers, with interannual variation driven largely by food resources, while variation across multiple seasons within a single cone year was less pronounced and lacked a dominant predictor of immune investment. However, we found weak evidence that physiological processes (e.g. reproductive condition, moult) or abiotic factors (e.g. temperature, precipitation) affect immune investment. Collectively, this study suggests that a reproductively flexible organism may be able to invest in both reproduction and survival-related processes, potentially by exploiting rich patches with abundant resources. More broadly, these results emphasize the need for more longitudinal studies of trade-offs associated with immune investment.


Assuntos
Passeriformes , Reprodução/fisiologia , Animais , Estações do Ano , Aves Canoras
15.
J Pathol ; 248(4): 452-463, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30916783

RESUMO

The establishment of the peristaltic machinery of the ureter is precisely controlled to cope with the onset of urine production in the fetal kidney. Retinoic acid (RA) has been identified as a signal that maintains the mesenchymal progenitors of the contractile smooth muscle cells (SMCs), while WNTs, SHH, and BMP4 induce their differentiation. How the activity of the underlying signalling pathways is controlled in time, space, and quantity to activate coordinately the SMC programme is poorly understood. Here, we provide evidence that the Zn-finger transcription factor GATA2 is involved in this crosstalk. In mice, Gata2 is expressed in the undifferentiated ureteric mesenchyme under control of RA signalling. Conditional deletion of Gata2 by a Tbx18cre driver results in hydroureter formation at birth, associated with a loss of differentiated SMCs. Analysis at earlier stages and in explant cultures revealed that SMC differentiation is not abrogated but delayed and that dilated ureters can partially regain peristaltic activity when relieved of urine pressure. Molecular analysis identified increased RA signalling as one factor contributing to the delay in SMC differentiation, possibly caused by reduced direct transcriptional activation of Cyp26a1, which encodes an RA-degrading enzyme. Our study identified GATA2 as a feedback inhibitor of RA signalling important for precise onset of ureteric SMC differentiation, and suggests that in a subset of cases of human congenital ureter dilatations, temporary relief of urine pressure may ameliorate the differentiation status of the SMC coat. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Diferenciação Celular , Fator de Transcrição GATA2/deficiência , Mesoderma/embriologia , Miócitos de Músculo Liso/fisiologia , Ureter/embriologia , Doenças Ureterais/embriologia , Animais , Biomarcadores/metabolismo , Feminino , Fator de Transcrição GATA2/genética , Masculino , Mesoderma/metabolismo , Camundongos , Transdução de Sinais , Tretinoína/metabolismo , Ureter/anormalidades , Ureter/metabolismo , Doenças Ureterais/congênito , Doenças Ureterais/metabolismo
16.
Curr Microbiol ; 77(10): 3136-3146, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32728792

RESUMO

Fermentative lactic acid production is currently impeded by low pH tolerance of the production organisms, the successive substrate consumption of the strains and/or the requirement to apply purified substrate streams. We identified Lactobacillus brevis IGB 1.29 in compost, which is capable of producing lactic acid at low pH values from lignocellulose hydrolysates, simultaneously consuming glucose and xylose. In this study, we compared Lactobacillus brevis IGB 1.29 with the reference strains Lactobacillus brevis ATCC 367, Lactobacillus plantarum NCIMB 8826 and Lactococcus lactis JCM 7638 with regard to the consumption of C5- and C6-sugars. Simultaneous conversion of C5- and C6-monosaccharides was confirmed for L. brevis IGB 1.29 with consumption rates of 1.6 g/(L h) for glucose and 1.0 g/(L h) for xylose. Consumption rates were lower for L. brevis ATCC 367 with 0.6 g/(L h) for glucose and 0.2 g/(L h) for xylose. Further trials were carried out to determine the sensitivity towards common toxic degradation products in lignocellulose hydrolysates: acetate, hydroxymethylfurfural, furfural, formate, levulinic acid and phenolic compounds from hemicellulose fraction. L. lactis was the least tolerant strain towards the inhibitors, whereas L. brevis IGB 1.29 showed the highest tolerance. L. brevis IGB 1.29 exhibited only 10% growth reduction at concentrations of 26.0 g/L acetate, 1.2 g/L furfural, 5.0 g/L formate, 6.6 g/L hydroxymethylfurfural, 9.2 g/L levulinic acid or 2.2 g/L phenolic compounds. This study describes a new strain L. brevis IGB 1.29, that enables efficient lactic acid production with a lignocellulose-derived C5- and C6-sugar fraction.


Assuntos
Levilactobacillus brevis , Xilose , Fermentação , Glucose , Lignina
17.
J Hepatol ; 71(2): 301-312, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31100314

RESUMO

BACKGROUND & AIMS: Hepatitis delta virus (HDV) infection is the most severe form of viral hepatitis. Although HDV-associated liver disease is considered immune-mediated, adaptive immune responses against HDV are weak. Thus, the role of several other cell-mediated mechanisms such as those driven by mucosa-associated invariant T (MAIT) cells, a group of innate-like T cells highly enriched in the human liver, has not been extensively studied in clinical HDV infection. METHODS: MAIT cells from a sizeable cohort of patients with chronic HDV were analyzed ex vivo and in vitro after stimulation. Results were compared with MAIT cells from hepatitis B virus (HBV) monoinfected patients and healthy controls. RESULTS: Circulating MAIT cells were dramatically decreased in the peripheral blood of HDV-infected patients. Signs of decline were also observed in the liver. In contrast, only a modest decrease of circulating MAIT cells was noted in HBV monoinfection. Unsupervised high-dimensional analysis of residual circulating MAIT cells in chronic HDV infection revealed the appearance of a compound phenotype of CD38hiPD-1hiCD28loCD127loPLZFloEomesloHelioslo cells indicative of activation. Corroborating these results, MAIT cells exhibited a functionally impaired responsiveness. In parallel to MAIT cell loss, HDV-infected patients exhibited signs of monocyte activation and increased levels of proinflammatory cytokines IL-12 and IL-18. In vitro, IL-12 and IL-18 induced an activated MAIT cell phenotype similar to the one observed ex vivo in HDV-infected patients. These cytokines also promoted MAIT cell death, suggesting that they may contribute to MAIT cell activation and subsequent loss during HDV infection. CONCLUSIONS: These results suggest that chronic HDV infection engages the MAIT cell compartment causing activation, functional impairment, and subsequent progressive loss of MAIT cells as the HDV-associated liver disease progresses. LAY SUMMARY: Hepatitis delta virus (HDV) infection is the most severe form of viral hepatitis. We found that in patients with HDV, a subset of innate-like T cells called mucosa-associated invariant T cells (or MAIT cells), which are normally abundant in peripheral blood and the liver, are activated, functionally impaired and severely depleted.


Assuntos
Hepatite D Crônica/imunologia , Vírus Delta da Hepatite/fisiologia , Ativação Linfocitária/imunologia , Células T Invariantes Associadas à Mucosa/imunologia , Adulto , Idoso , Linfócitos T CD8-Positivos/imunologia , Estudos de Coortes , Feminino , Células Hep G2 , Hepatite D Crônica/virologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Interleucina-12/sangue , Interleucina-18/sangue , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor/metabolismo , Fenótipo , Receptores de Antígenos de Linfócitos T/metabolismo , Adulto Jovem
18.
J Hepatol ; 70(4): 603-614, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30472319

RESUMO

BACKGROUND & AIMS: The lipid-binding protein, SEC14L2, is crucial for the efficient viral replication of clinical hepatitis C virus (HCV) isolates in cell culture. Given the role of SEC14L2 in HCV replication, we aimed to study a large number of HCV positive sera carrying genotypes 1-4, to identify viral factors associated with efficient replication in culture. Additionally, we investigated whether 13 single nucleotide polymorphisms (SNPs) of SEC14L2 have an impact on RNA replication of naturally occurring HCV isolates. METHODS: We generated Huh-7.5 cell lines overexpressing SEC14L2 or 13 coding SNPs and tested 73 different HCV positive sera for in vitro replication. Furthermore, we genotyped a cohort of 262 patients with chronic HCV for the common SNP (rs757660) and investigated its effect on the clinical phenotype. RESULTS: HCV isolates from genotype 1, 2, 3 and 4 replicate in Huh-7.5 cells overexpressing SEC14L2. Interestingly, only subgenomic replicons from genotypes 1 and 3 showed enhanced replication whereas genotypes 2 and 4 remained unaffected. Furthermore, replication was independent of viral load. Importantly, all tested SNPs supported HCV RNA replication in vitro, while 1 SNP was associated with decreased SEC1L2 expression and viral RNA. All SNPs exhibited comparable cellular cholesterol and vitamin E abundance in naïve Huh-7.5 cells. CONCLUSIONS: This large screen of natural HCV isolates of 4 genotypes underscores the relevance of SEC14L2 as an in vitro HCV host factor. Additionally, SEC14L2 variants appear to recapitulate the wild-type enhancement of HCV replication. Variant rs191341134 showed a decreased effect due to lowered stability, whereas variant rs757660, a high prevalence mutant, showed a similar phenotype to the wild-type. LAY SUMMARY: Until the year 2015, consistent replication of patient-derived isolates of hepatitis C virus (HCV) in an in vitro model remained a limitation in HCV research. In 2015 a group of authors identified a protein named SEC14L2 that enabled the replication of HCV isolates in cell culture. We performed a large screen encompassing 73 isolates of 4 different HCV genotypes. Additionally, we replaced the natural SEC14L2 with 13 different mutants to test if the protein variation significantly altered its HCV replication enhancing functions. We showed that different genotypes of HCV react differently to the presence of this protein and the variants of the protein mimic the behavior of the wild-type.


Assuntos
Proteínas de Transporte/metabolismo , Genótipo , Hepacivirus/genética , Hepatite C Crônica/genética , Lipoproteínas/metabolismo , Transativadores/metabolismo , Replicação Viral/genética , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Estudos de Coortes , Citosol/metabolismo , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Humanos , Lipoproteínas/genética , Proteínas Mutantes/metabolismo , Fenótipo , Polimorfismo de Nucleotídeo Único , Isoformas de Proteínas/genética , RNA Viral/genética , RNA Viral/isolamento & purificação , Replicon , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores/genética , Transdução Genética
19.
Gastroenterology ; 154(4): 976-988.e4, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29146520

RESUMO

BACKGROUND & AIMS: Little is known about substitutions that mediate resistance of hepatitis C virus (HCV) to direct-acting antivirals (DAAs), due to the small number of patients with treatment failure in approval studies. It is important to identify resistance patterns to select effective salvage treatments. METHODS: We performed a comprehensive analysis for resistance-associated substitutions (RASs) in HCV genes (nonstructural protein [NS]3, NS5A, NS5B) targeted by DAAs. We compared NS3, NS5A, and NS5B sequences from 626 patients in Europe with DAA failure with sequences from 2322 DAA-naïve patients, infected with HCV genotypes 1 to 4. We considered RASs to be relevant if they were associated with DAA failure in patients or conferred a greater than twofold change in susceptibility compared with a reference strain in in vitro replicon assays. Data were collected on pretreatment status, DAA regimen, the treatment initiation date and duration, and virologic response. Patients who received at least 4 weeks of antiviral treatment were included in the analysis. RESULTS: RASs in NS3 associated with simeprevir or paritaprevir failure include R155K and D168E/V. In addition, several RASs were specifically associated with failure of simeprevir (Q80K/R in patients with genotype 1a or 4) or paritaprevir (Y56H in combination with D168V in patients with genotype 1b). Y93H in NS5A was the RAS most frequently associated with failure of daclatasvir, ledipasvir, or ombitasvir in patients with genotype 1b infection, and L31M was associated with failure of daclatasvir or ledipasvir, but not ombitasvir. RASs in NS5A were heterogeneous among patients with HCV genotype 1a or genotype 4 infections. In patients with HCV genotype 3, Y93H was associated with resistance to daclatasvir, but no RASs were associated with ledipasvir failure, pointing to a limited efficacy of ledipasvir in patients with genotype 3. Among patients failed by sofosbuvir-containing regimens, L159F was enriched in patients with genotype 1b (together with C316N) or genotype 3 infection, whereas the RAS S282T was rarely observed. CONCLUSIONS: We compared RASs in NS3, NS5A, and NS5B among patients failed by DAA therapy. Theses varied with the HCV genotype and subtype, and the different drug classes. These findings might be used to select salvage therapies.


Assuntos
Antivirais/uso terapêutico , Farmacorresistência Viral/genética , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Inibidores de Proteases/uso terapêutico , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/efeitos adversos , Substituição de Medicamentos , Quimioterapia Combinada , Europa (Continente) , Genótipo , Hepacivirus/enzimologia , Hepacivirus/genética , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/virologia , Humanos , Fenótipo , Inibidores de Proteases/efeitos adversos , Retratamento , Estudos Retrospectivos , Fatores de Tempo , Falha de Tratamento , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
20.
Horm Behav ; 110: 10-18, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30735664

RESUMO

In many passerine birds, testosterone stimulates song and aggression but inhibits paternal care, but few studies have explored whether such effects can be reversed with testosterone blockers. We explored the effect of testosterone blockers on song, aggression and paternal care of Lapland longspurs (Calcarius lapponicus), an arctic passerine with a short breeding season. Twenty-one "blocker males" received implants containing an androgen receptor blocker and an aromatase inhibitor, compared to 27 control males with empty or no implants. Song, aggression and other behaviors were evaluated with simulated territorial intrusions (STI) during mate-guarding, and with focal observations (without STI) during mate-guarding and incubation. Nests were monitored and nestlings weighed as an indirect measure of paternal care. During STI, blocker males exhibited similar song rates, significantly lower aggression, and were significantly less likely to be found on territory than control males. Focal observations revealed no differences in spontaneous song, aggression, foraging, preening, or flight activity. Blocker males' nestlings had greater body mass on day 5 after hatching, but this difference disappeared by fledging, and both groups fledged similar numbers of young. Two blocker males exhibited unusual paternal care: incubation and brooding of young, or feeding of nestlings at another male's nest. In sum, testosterone blockers affected aggression but not song, contrasting with results from previously published testosterone implant studies. Effects on paternal care were concordant with testosterone implant studies. These patterns may be related to rapid behavioral changes characteristic of the short breeding season of the Arctic.


Assuntos
Agressão/efeitos dos fármacos , Antagonistas de Receptores de Andrógenos/farmacologia , Comportamento de Nidação/efeitos dos fármacos , Passeriformes/fisiologia , Comportamento Paterno/efeitos dos fármacos , Testosterona/antagonistas & inibidores , Vocalização Animal/efeitos dos fármacos , Animais , Regiões Árticas , Masculino , Receptores Androgênicos/metabolismo , Reprodução/efeitos dos fármacos , Estações do Ano , Territorialidade , Testosterona/farmacologia
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