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1.
Nano Lett ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38885473

RESUMO

Vertical gate-all-around (V-GAA) represents the ultimate configuration in the forthcoming transistor industry, but it still encounters challenges in the semiconductor community. This paper introduces, for the first time, a dual-input logic gate circuit achieved using 3D vertical transistors with nanoscale sub-20-nm GAA, employing a novel technique for creating contacts and patterning metallic lines at the bottom level without the conventional lift-off process. This involves a two-step oxidation process: patterning the first field oxide to form bottom metal lines and then creating the gate oxide layer on nanowires (NWs), followed by selective removal from the top and bottom of the nanostructures. VGAA-NW transistors, fabricated using the lift-off-free approach, exhibit improved yield and reduced access resistance, leading to an enhanced drive current while maintaining good immunity against short-channel effects. Finally, elementary two-input logic gates within a single cell, using VNW transistors, demonstrate novel possibilities in advanced logic circuitry design and routing options in 3D.

2.
Plant Physiol ; 191(1): 125-141, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36222581

RESUMO

According to their lifestyle, plant pathogens are divided into biotrophic and necrotrophic organisms. Biotrophic pathogens exclusively nourish living host cells, whereas necrotrophic pathogens rapidly kill host cells and nourish cell walls and cell contents. To this end, the necrotrophic fungus Botrytis cinerea secretes large amounts of phytotoxic proteins and cell wall-degrading enzymes. However, the precise role of these proteins during infection is unknown. Here, we report on the identification and characterization of the previously unknown toxic protein hypersensitive response-inducing protein 1 (Hip1), which induces plant cell death. We found the adoption of a structurally conserved folded Alternaria alternata Alt a 1 protein structure to be a prerequisite for Hip1 to exert its necrosis-inducing activity in a host-specific manner. Localization and the induction of typical plant defense responses by Hip1 indicate recognition as a pathogen-associated molecular pattern at the plant plasma membrane. In contrast to other secreted toxic Botrytis proteins, the activity of Hip1 does not depend on the presence of the receptor-associated kinases BRI1-associated kinase 1 and suppressor of BIR1-1. Our results demonstrate that recognition of Hip1, even in the absence of obvious enzymatic or pore-forming activity, induces strong plant defense reactions eventually leading to plant cell death. Botrytis hip1 overexpression strains generated by CRISPR/Cas9 displayed enhanced infection, indicating the virulence-promoting potential of Hip1. Taken together, Hip1 induces a noncanonical defense response which might be a common feature of structurally conserved fungal proteins from the Alt a 1 family.


Assuntos
Botrytis , Células Vegetais , Botrytis/metabolismo , Morte Celular , Virulência , Membrana Celular , Doenças das Plantas/microbiologia , Regulação da Expressão Gênica de Plantas
3.
J Anat ; 244(4): 594-600, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38030157

RESUMO

Pelvic incidence and lumbar lordosis have only normative values for spines comprising five lumbar and five sacral vertebrae. However, it is unclear how pelvic incidence and lumbar lordosis are affected by the common segmentation anomalies at the lumbo-sacral border leading to lumbosacral transitional vertebrae, including lumbarisations and sacralisations. In lumbosacral transitional vertebrae it is not trivial to identify the correct vertebral endplates to measure pelvic incidence and lumbar lordosis because ontogenetically the first sacral vertebra represents the first non-mobile sacral segment in lumbarisations, but the second segment in sacralisations. We therefore assessed pelvic incidence and lumbar lordosis with respect to both of these vertebral endplates. The type of segmentation anomaly was differentiated using spinal counts, spatial relationship with the iliac crest and morphological features. We found significant differences in pelvic incidence and lumbar lordosis between lumbarisations, sacralisations and the control group. The pelvic incidence in the sacralised group was mostly below the range of the lubarisation group and the control group when measured the traditional way at the first non-mobile segment (30.2°). However, the ranges of the sacralisation and lubarisation groups were completely encompassed by the control group when measured at the ontogenetically true first sacral vertebra. The mean pelvic incidence of the sacraliation group thus increased from 30.2° to 58.6°, and the mean pelvic incidence of the total sample increased from 45.6° to 51.2°, making it statistically indistinguishable from the control sample, whose pelvic incidence was 50.2°. Our results demonstrate that it is crucial to differentiate sacralisations from lumbarisation in order to assess the reference vertebra for pelvic incidence measurement. Due to their significant impact on spino-pelvic parameters, lumbosacral transitional vertebrae should be evaluated separately when examining pelvic incidence and lumbar lordosis.


Assuntos
Lordose , Humanos , Lordose/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/anatomia & histologia , Sacro/diagnóstico por imagem , Sacro/anatomia & histologia , Pelve/diagnóstico por imagem , Pelve/anatomia & histologia , Região Lombossacral/diagnóstico por imagem , Estudos Retrospectivos
4.
Clin Infect Dis ; 76(3): e841-e848, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35881530

RESUMO

BACKGROUND: Lassa fever is endemic in large parts of West Africa. The recommended antiviral treatment is ribavirin. Two treatment regimens are currently endorsed in Nigeria: the "McCormick regimen" based on a study published in 1986 and the "Irrua regimen" constituting a simplified schedule developed at the Irrua Specialist Teaching Hospital, Nigeria. Evidence for the safety and efficacy of ribavirin in Lassa fever patients is poor and pharmacokinetic data for both regimens are lacking. METHODS: Polymerase chain reaction-confirmed Lassa fever patients with mild to moderate disease severity were invited to participate in this prospective, observational pharmacokinetic study. Pharmacokinetics of ribavirin, clinical, virologic, and clinical laboratory parameters were assessed. RESULTS: Using a population pharmacokinetic approach, plasma concentrations of ribavirin were best described by a 3-compartment model. Drug exposure was remarkably consistent between participants. Overall, drug clearance was 28.5% lower in female compared with male participants. Median (5th-95th percentile) time above half maximal inhibitory concentration (IC50) was 37.3% (16.9%-73.1%), 16.7% (8.2%-58.5%), and 9.6% (4.9%-38.4%) on days 1, 7, and 8, respectively. Clinical laboratory parameters indicated reduction of cell damage and development of hemolytic anemia in the course of the treatment period. CONCLUSIONS: This observational study characterizes the pharmacokinetics of ribavirin in the treatment of Lassa fever indicating consistent exposure across patients. Whereas only a short time interval of concentrations above the IC50 implies rather low antiviral efficacy in vivo, the prominent reduction of cell damage markers might point to indirect-potentially anti-inflammatory-effects of ribavirin. The role of ribavirin in the treatment of Lassa fever requires further scrutiny.


Assuntos
Febre Lassa , Humanos , Masculino , Feminino , Febre Lassa/tratamento farmacológico , Ribavirina/uso terapêutico , Nigéria/epidemiologia , Estudos Prospectivos , Antivirais/uso terapêutico , Hospitais de Ensino
5.
J Org Chem ; 88(19): 14184-14188, 2023 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-37708429

RESUMO

The myxobacterial natural product myxocoumarin A from Stigmatella aurantiaca MYX-030 has remarkable antifungal activity against agriculturally relevant pathogens. To broaden the initial evaluation of its biological potential, we herein completed the first total synthesis of myxocoumarin A. This synthetic access facilitated stereochemical investigations on the natural product structure, revealing its (R)-configuration. Biological activity profiling showed a lack of activity against Candida spp. and Gram-negative bacteria but revealed strong antibiotic activities against Bacillus subtilis and Staphylococcus aureus, including MRSA.


Assuntos
Anti-Infecciosos , Produtos Biológicos , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Antifúngicos/química , Antibacterianos/química
6.
Int J Mol Sci ; 24(12)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37373482

RESUMO

Advances in spine surgery enable technically safe interventions in older patients with disabling spine disease, yet postoperative delirium (POD) poses a serious risk for postoperative recovery. This study investigates biomarkers of pro-neuroinflammatory states that may help objectively define the pre-operative risk for POD. This study enrolled patients aged ≥60 scheduled for elective spine surgery under general anesthesia. Biomarkers for a pro-neuroinflammatory state included S100 calcium-binding protein ß (S100ß), brain-derived neurotrophic factor (BDNF), Gasdermin D, and the soluble ectodomain of the triggering receptor expressed on myeloid cells 2 (sTREM2). Postoperative changes of Interleukin-6 (IL-6), Interleukin-1ß (IL-1ß), and C-reactive protein (CRP) were assessed as markers of systemic inflammation preoperatively, intraoperatively, and early postoperatively (up to 48 h). Patients with POD (n = 19, 75.7 ± 5.8 years) had higher pre-operative levels of sTREM2 (128.2 ± 69.4 pg/mL vs. 97.2 ± 52.0 pg/mL, p = 0.049) and Gasdermin D (2.9 ± 1.6 pg/mL vs. 2.1 ± 1.4 pg/mL, p = 0.29) than those without POD (n = 25, 75.6 ± 5.1 years). STREM2 was additionally a predictor for POD (OR = 1.01/(pg/mL) [1.00-1.03], p = 0.05), moderated by IL-6 (Wald-χ2 = 4.06, p = 0.04). Patients with POD additionally showed a significant increase in IL-6, IL-1ß, and S100ß levels on the first postoperative day. This study identified higher levels of sTREM2 and Gasdermin D as potential markers of a pro-neuroinflammatory state that predisposes to the development of POD. Future studies should confirm these results in a larger cohort and determine their potential as an objective biomarker to inform delirium prevention strategies.


Assuntos
Delírio , Delírio do Despertar , Humanos , Idoso , Interleucina-6/metabolismo , Delírio/diagnóstico , Delírio/etiologia , Gasderminas , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Biomarcadores/metabolismo
7.
Plant Physiol ; 187(4): 2716-2730, 2021 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-34597404

RESUMO

Root growth and architecture are markedly influenced by both developmental and environmental cues. Sugars integrate different stimuli and are essential building blocks and signaling molecules for modulating the root system. Members from the SUGAR WILL EVENTUALLY BE EXPORTED TRANSPORTER (SWEET) family facilitate the transport of different sugars over cellular membranes and steer both inter and intracellular distribution of sugars. SWEET17 represents a fructose-specific sugar porter localized to the vacuolar membrane, the tonoplast. Here, we analyzed how SWEET17-dependent fructose released from vacuoles affects root growth during drought stress in Arabidopsis (Arabidopsis thaliana). We found that the SWEET17 gene was predominantly expressed in the root vasculature and in meristematic cells of the root tip. SWEET17 expression appeared markedly induced during lateral root (LR) outgrowth and under drought. Moreover, fructose repressed primary root growth but induced density and length of first order LRs. Consistently, sweet17 knock-out mutants exhibited reduced LR growth and a diminished expression of LR-development-related transcription factors during drought stress, resulting in impaired drought tolerance of sweet17 mutants. We discuss how SWEET17 activity integrates drought-induced cellular responses into fructose signaling necessary for modulation of the root system and maximal drought tolerance.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Secas , Proteínas de Membrana Transportadoras/genética , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/genética
8.
Chemistry ; 28(32): e202200394, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35229915

RESUMO

The increasing emergence of resistances against established antibiotics is a substantial threat to human health. The discovery of new compounds with potent antibiotic activity is thus of utmost importance. Within this work, we identify strong antibiotic activity of the natural product myxocoumarin B from Stigmatella aurantiaca MYX-030 against a range of clinically relevant bacterial pathogens, including clinical isolates of MRSA. A focused library of structural analogs was synthesized to explore initial structure-activity relationships and to identify equipotent myxocoumarin derivatives devoid of the natural nitro substituent to significantly streamline synthetic access. The cytotoxicity of the myxocoumarins as well as their potential to cure bacterial infections in vivo was established using a zebrafish model system. Our results reveal the exceptional antibiotic activity of the myxocoumarin scaffold and hence its potential for the development of novel antibiotics.


Assuntos
Produtos Biológicos , Staphylococcus aureus Resistente à Meticilina , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Peixe-Zebra
9.
Ann Bot ; 129(7): 775-786, 2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35303062

RESUMO

BACKGROUND AND AIMS: Interactions between ecological factors and seed physiological responses during the establishment phase shape the distribution of plants. Yet, our understanding of the functions and evolution of early-life traits has been limited by the scarcity of large-scale datasets. Here, we tested the hypothesis that the germination niche of temperate plants is shaped by their climatic requirements and phylogenetic relatedness, using germination data sourced from a comprehensive seed conservation database of the European flora (ENSCOBASE). METHODS: We performed a phylogenetically informed Bayesian meta-analysis of primary data, considering 18 762 germination tests of 2418 species from laboratory experiments conducted across all European geographical regions. We tested for the interaction between species' climatic requirements and germination responses to experimental conditions including temperature, alternating temperature, light and dormancy-breaking treatments, while accounting for between-study variation related to seed sources and seed lot physiological status. KEY RESULTS: Climate was a strong predictor of germination responses. In warm and seasonally dry climates the seed germination niche includes a cold-cued germination response and an inhibition determined by alternating temperature regimes and cold stratification, while in climates with high temperature seasonality opposite responses can be observed. Germination responses to scarification and light were related to seed mass but not to climate. We also found a significant phylogenetic signal in the response of seeds to experimental conditions, providing evidence that the germination niche is phylogenetically constrained. Nevertheless, phylogenetically distant lineages exhibited common germination responses under similar climates. CONCLUSION: This is the first quantitative meta-analysis of the germination niche at a continental scale. Our findings showed that the germination niches of European plants exhibit evolutionary convergence mediated by strong pressures at the macroclimatic level. In addition, our methodological approach highlighted how large datasets generated by conservation seed banking can be valuable sources to address questions in plant macroecology and evolution.


Assuntos
Germinação , Magnoliopsida , Teorema de Bayes , Germinação/fisiologia , Filogenia , Dormência de Plantas , Plantas , Sementes/fisiologia , Temperatura
10.
Proc Natl Acad Sci U S A ; 116(11): 4923-4927, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30804177

RESUMO

Although the early postural reconstructions of the Neandertals as incompletely erect were rejected half a century ago, recent studies of Neandertal vertebral remains have inferred a hypolordotic, flat lower back and spinal imbalance for them, including the La Chapelle-aux-Saints 1 skeleton. These studies form part of a persistent trend to view the Neandertals as less "human" than ourselves despite growing evidence for little if any differences in basic functional anatomy and behavioral capabilities. We have therefore reassessed the spinal posture of La Chapelle-aux-Saints 1 using a new pelvic reconstruction to infer lumbar lordosis, interarticulation of lower lumbar (L4-S1) and cervical (C4-T2) vertebrae, and consideration of his widespread age-related osteoarthritis. La Chapelle-aux-Saints 1 exhibits a pelvic incidence (and hence lumbar lordosis) similar to modern humans, articulation of lumbar and cervical vertebrae indicating pronounced lordosis, and Baastrup disease as a product of his advanced age, osteoarthritis, and lordosis. Our findings challenge the view of generally small spinal curvatures in Neandertals. Setting aside the developmentally abnormal Kebara 2 vertebral column, La Chapelle-aux-Saints 1 is joined by other Neandertals with sufficient vertebral remains in providing them with a fully upright (and human) axial posture.


Assuntos
Homem de Neandertal/anatomia & histologia , Homem de Neandertal/fisiologia , Postura , Coluna Vertebral/patologia , Idoso , Animais , Humanos , Masculino , Osteoartrite/patologia , Osteoartrite/fisiopatologia , Pelve/anatomia & histologia , Curvaturas da Coluna Vertebral/fisiopatologia , Coluna Vertebral/fisiopatologia
11.
Int J Mol Sci ; 23(15)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35955449

RESUMO

Aims: Some gene variants in the sodium channels, as well as calcium channels, have been associated with Brugada syndrome (BrS). However, the investigation of the human cellular phenotype and the use of drugs for BrS in presence of variant in the calcium channel subunit is still lacking. Objectives: The objective of this study was to establish a cellular model of BrS in the presence of a CACNB2 variant of uncertain significance (c.425C > T/p.S142F) using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and test drug effects using this model. Methods and results: This study recruited cells from a patient with Brugada syndrome (BrS) and recurrent ventricular fibrillation carrying a missense variant in CACNB2 as well as from three healthy independent persons. These cells (hiPSC-CMs) generated from skin biopsies of healthy persons and the BrS patient (BrS-hiPSC-CMs) as well as CRISPR/Cas9 corrected cells (isogenic control, site-variant corrected) were used for this study. The hiPSC-CMs from the BrS patient showed a significantly reduced L-type calcium channel current (ICa-L) compared with the healthy control hiPSC-CMs. The inactivation curve was shifted to a more positive potential and the recovery from inactivation was accelerated. The protein expression of CACNB2 of the hiPSC-CMs from the BrS-patient was significantly decreased compared with healthy hiPSC-CMs. Moreover, the correction of the CACNB2 site-variant rescued the changes seen in the hiPSC-CMs of the BrS patient to the normal state. These data indicate that the CACNB2 gene variant led to loss-of-function of L-type calcium channels in hiPSC-CMs from the BrS patient. Strikingly, arrhythmia events were more frequently detected in BrS-hiPSC-CMs. Bisoprolol (beta-blockers) at low concentration and quinidine decreased arrhythmic events. Conclusions: The CACNB2 variant (c.425C > T/p.S142F) causes a loss-of-function of L-type calcium channels and is pathogenic for this type of BrS. Bisoprolol and quinidine may be effective for treating BrS with this variant.


Assuntos
Síndrome de Brugada , Células-Tronco Pluripotentes Induzidas , Potenciais de Ação , Arritmias Cardíacas/metabolismo , Bisoprolol/farmacologia , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Humanos , Miócitos Cardíacos/metabolismo , Quinidina/farmacologia
12.
J Virol ; 94(21)2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-32817220

RESUMO

Lassa fever (LF) is a zoonotic viral hemorrhagic fever caused by Lassa virus (LASV), which is endemic to West African countries. Previous studies have suggested an important role for T-cell-mediated immunopathology in LF pathogenesis, but the mechanisms by which T cells influence disease severity and outcome are not well understood. Here, we present a multiparametric analysis of clinical immunology data collected during the 2017-2018 Lassa fever outbreak in Nigeria. During the acute phase of LF, we observed robust activation of the polyclonal T-cell repertoire, which included LASV-specific and antigenically unrelated T cells. However, severe and fatal LF cases were characterized by poor LASV-specific effector T-cell responses. Severe LF was also characterized by the presence of circulating T cells with homing capacity to inflamed tissues, including the gut mucosa. These findings in LF patients were recapitulated in a mouse model of LASV infection, in which mucosal exposure resulted in remarkably high lethality compared to skin exposure. Taken together, our findings indicate that poor LASV-specific T-cell responses and activation of nonspecific T cells with homing capacity to inflamed tissues are associated with severe LF.IMPORTANCE Lassa fever may cause severe disease in humans, in particular in areas of endemicity like Sierra Leone and Nigeria. Despite its public health importance, the pathophysiology of Lassa fever in humans is poorly understood. Here, we present clinical immunology data obtained in the field during the 2018 Lassa fever outbreak in Nigeria indicating that severe Lassa fever is associated with activation of T cells antigenically unrelated to Lassa virus and poor Lassa virus-specific effector T-cell responses. Mechanistically, we show that these bystander T cells express defined tissue homing signatures that suggest their recruitment to inflamed tissues and a putative role of these T cells in immunopathology. These findings open a window of opportunity to consider T-cell targeting as a potential postexposure therapeutic strategy against severe Lassa fever, a hypothesis that could be tested in relevant animal models, such as nonhuman primates.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Surtos de Doenças , Mucosa Intestinal/imunologia , Febre Lassa/imunologia , Vírus Lassa/patogenicidade , Ativação Linfocitária , Adolescente , Adulto , Idoso , Animais , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/virologia , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Humanos , Lactente , Recém-Nascido , Integrina beta1/genética , Integrina beta1/imunologia , Interferon gama/genética , Interferon gama/imunologia , Mucosa Intestinal/patologia , Mucosa Intestinal/virologia , Febre Lassa/genética , Febre Lassa/mortalidade , Febre Lassa/virologia , Vírus Lassa/crescimento & desenvolvimento , Vírus Lassa/imunologia , Proteína 1 de Membrana Associada ao Lisossomo/genética , Proteína 1 de Membrana Associada ao Lisossomo/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Nigéria/epidemiologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Pele/imunologia , Pele/patologia , Pele/virologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
13.
Acta Neurochir (Wien) ; 163(6): 1577-1581, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33674887

RESUMO

BACKGROUND: Instrumentation of the lumbosacral region is one of the more challenging regions due to the complex anatomical structures and biomechanical forces. Screw insertion can be done both navigated and based on X-ray verification. In this study, we demonstrate a fast and reliable open, low exposure X-ray-guided technique of iliac screw placement. METHODS: Between October 2016 and August 2019, 48 patients underwent sacropelvic fixation in tear-drop technique. Screw insertion was performed in open technique by using an X-ray converter angulated 25-30° in coronal and sagittal view. The anatomical insertion point was the posterior superior iliac spine. Verification of correct screw placement was done by intraoperative 3D scan. RESULTS: In total, 95 iliac screws were placed in tear-drop technique with a correct placement in 98.1%. CONCLUSIONS: The tear-drop technique showed a proper screw position in the intraoperative 3D scan and therefore may be considered an alternative technique to the navigated screw placement.


Assuntos
Parafusos Ósseos , Ílio/cirurgia , Fusão Vertebral/métodos , Adulto , Idoso , Fenômenos Biomecânicos , Humanos , Ílio/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
14.
Chembiochem ; 21(4): 492-495, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31448469

RESUMO

Sorbicillinoids are fungal polyketides characterized by highly complex and diverse molecular structures, with considerable stereochemical intricacy combined with a high degree of oxygenation. Many sorbicillinoids possess promising biological activities. An interesting member of this natural product family is sorbicatechol A, which is reported to have antiviral activity, particularly against influenza A virus (H1N1). Through a straightforward, one-pot chemoenzymatic approach with recently developed oxidoreductase SorbC, the characteristic bicyclo[2.2.2]octane core of sorbicatechol is structurally diversified by variation of its natural 2-methoxyphenol substituent. This facilitates the preparation of a focused library of structural analogues bearing substituted aromatic systems, alkanes, heterocycles, and ethers. Fast access to this structural diversity provides an opportunity to explore the antiviral potential of the sorbicatechol family.


Assuntos
Antivirais/química , Antivirais/síntese química , Policetídeos , Antivirais/farmacologia , HIV/efeitos dos fármacos , Alphainfluenzavirus/efeitos dos fármacos , Estrutura Molecular , Policetídeos/síntese química , Policetídeos/química
15.
Conserv Biol ; 34(2): 303-313, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31329316

RESUMO

The alarming current and predicted species extinction rates have galvanized conservationists in their efforts to avoid future biodiversity losses, but for species extinct in the wild, few options exist. We posed the questions, can these species be restored, and, if so, what role can ex situ plant collections (i.e., botanic gardens, germplasm banks, herbaria) play in the recovery of plant genetic diversity? We reviewed the relevant literature to assess the feasibility of recovering lost plant genetic diversity with using ex situ material and the probability of survival of subsequent translocations. Thirteen attempts to recover species extinct in the wild were found, most of which used material preserved in botanic gardens (12) and seed banks (2). One case of a locally extirpated population was recovered from herbarium material. Eight (60%) of these cases were successful or partially successful translocations of the focal species or population; the other 5 failed or it was too early to determine the outcome. Limiting factors of the use of ex situ source material for the restoration of plant genetic diversity in the wild include the scarcity of source material, low viability and reduced longevity of the material, low genetic variation, lack of evolution (especially for material stored in germplasm banks and herbaria), and socioeconomic factors. However, modern collecting practices present opportunities for plant conservation, such as improved collecting protocols and improved cultivation and storage conditions. Our findings suggest that all types of ex situ collections may contribute effectively to plant species conservation if their use is informed by a thorough understanding of the aforementioned problems. We conclude that the recovery of plant species currently classified as extinct in the wild is not 100% successful, and the possibility of successful reintroduction should not be used to justify insufficient in situ conservation.


Colecciones Ex Situ y su Potencial para la Restauración de Plantas Extintas Resumen Las alarmantes tasas de extinción actuales y pronosticadas han incitado a los conservacionistas a esforzarse para evitar las futuras pérdidas de biodiversidad, pero para las especies que ya se encuentran extintas en vida silvestre existen pocas opciones. Nos preguntamos si estas especies pueden ser restauradas, y de ser así, qué papel pueden desempeñar las colecciones ex situ de plantas (es decir, jardines botánicos, bancos de germoplasma, herbarios) en la recuperación de la diversidad genética de las plantas. Revisamos la literatura relevante para evaluar la factibilidad de la recuperación de la diversidad genética perdida y la probabilidad de supervivencia subsecuente de las reubicaciones. Encontramos 13 intentos por recuperar especies extintas en vida silvestre, la mayoría de los cuales usó material preservado en jardines botánicos (12) y en bancos de semillas (2). También hubo un caso de una población eliminada localmente que fue recuperada con material de un herbario. Ocho (60%) de estos casos fueron reubicaciones exitosas o parcialmente exitosas de la especie o población focal; los otros cinco fallaron o era demasiado pronto para poder determinar el resultado. Los factores que limitan el uso de material proveniente de colecciones ex situ para la restauración de la diversidad genética de las plantas en vida silvestre incluyen la escasez de material original, la baja viabilidad y la longevidad reducida del material, la baja variación genética, la falta de evolución (especialmente para el material almacenado en herbarios y bancos de germoplasma) y los factores socioeconómicos. A pesar de esto, las prácticas modernas de colección representan una oportunidad para la conservación de las plantas, como los protocolos mejorados de recolección y las condiciones acrecentadas de cultivo y almacenamiento. Nuestros hallazgos sugieren que todos los tipos de colecciones ex situ pueden contribuir efectivamente a la conservación de especies de plantas si su uso está respaldado por un entendimiento a fondo de los problemas antes mencionados. Concluimos que la recuperación de especies de plantas que actualmente están clasificadas como extintas en vida silvestre no es 100% exitosa y que la posibilidad de una reintroducción exitosa no debería utilizarse para justificar una conservación in situ insuficiente.


Assuntos
Conservação dos Recursos Naturais , Banco de Sementes , Biodiversidade , Jardinagem , Plantas
16.
Org Biomol Chem ; 17(7): 1966-1969, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30357251

RESUMO

The myxocoumarins A and B from Stigmatella aurantiaca MYX-030 are natural products featuring unusual nitro- and long-chain alkyl substitution. While myxocoumarin A was shown to exhibit strong antifungal properties, the antifungal potential of myxocoumarin B was not yet assessed due to low production titers during initial isolation. We therefore developed a total synthesis of myxocoumarin B that involves a late-stage Pd-catalyzed nitration of the coumarin core. The availability of synthetic material facilitated the initial evaluation of the bioactivity of myxocoumarin B, which revealed a lack of activity against medically relevant Candida sp. and low cytotoxicity in vitro against human fibroblasts (MRC-5) and in vivo (zebrafish).


Assuntos
Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Produtos Biológicos/farmacologia , Botrytis/efeitos dos fármacos , Cumarínicos/farmacologia , Fibroblastos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Animais , Antifúngicos/síntese química , Antifúngicos/química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Cumarínicos/síntese química , Cumarínicos/química , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Stigmatella aurantiaca/química , Relação Estrutura-Atividade , Peixe-Zebra/embriologia
17.
Europace ; 21(9): 1410-1421, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31106349

RESUMO

AIMS: Brugada syndrome (BrS) is associated with a pronounced risk to develop sudden cardiac death (SCD). Up to 21% of patients are related to mutations in SCN5A. Studies identified SCN10A as a contributor of BrS. However, the investigation of the human cellular phenotype of BrS in the presence of SCN10A mutations remains lacking. The objective of this study was to establish a cellular model of BrS in presence of SCN10A mutations using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS AND RESULTS: Dermal fibroblasts obtained from a BrS patient suffering from SCD harbouring the SCN10A double variants (c.3803G>A and c.3749G>A) and three independent healthy control subjects were reprogrammed to hiPSCs. Human-induced pluripotent stem cells were differentiated into cardiomyocytes (hiPSC-CMs).The hiPSC-CMs from the BrS patient showed a significantly reduced peak sodium channel current (INa) and a significantly reduced ATX II (sea anemone toxin, an enhancer of late INa) sensitive as well as A-887826 (a blocker of SCN10A channel) sensitive late sodium channel current (INa) when compared with the healthy control hiPSC-CMs, indicating loss-of-function of sodium channels. Consistent with reduced INa the action potential amplitude and upstroke velocity (Vmax) were significantly reduced, which may contribute to arrhythmogenesis of BrS. Moreover, Ajmaline effects on action potentials were stronger in BrS-hiPSC-CMs than in healthy control cells. This is in agreement with the higher susceptibility of patients to sodium channel blocking drugs in unmasking BrS. CONCLUSION: Patient-specific hiPSC-CMs are able to recapitulate single-cell phenotype features of BrS with SCN10A mutations and may provide novel opportunities to further elucidate the cellular disease mechanism.


Assuntos
Potenciais de Ação/fisiologia , Síndrome de Brugada/genética , Miócitos Cardíacos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.8/genética , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/genética , Ajmalina/farmacologia , Síndrome de Brugada/metabolismo , Cardiotônicos/farmacologia , Estudos de Casos e Controles , Técnicas de Reprogramação Celular , Venenos de Cnidários/farmacologia , Morte Súbita Cardíaca , Humanos , Células-Tronco Pluripotentes Induzidas , Mutação com Perda de Função , Masculino , Pessoa de Meia-Idade , Morfolinas/farmacologia , Mutação , Miócitos Cardíacos/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.8/metabolismo , Niacinamida/análogos & derivados , Niacinamida/farmacologia , Técnicas de Patch-Clamp , Fenótipo , Taquicardia Ventricular , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia
18.
Sensors (Basel) ; 19(16)2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31434320

RESUMO

Lower back pain is one of the most prevalent diseases in Western societies. A large percentage of European and American populations suffer from back pain at some point in their lives. One successful approach to address lower back pain is postural training, which can be supported by wearable devices, providing real-time feedback about the user's posture. In this work, we analyze the changes in posture induced by postural training. To this end, we compare snapshots before and after training, as measured by the Gokhale SpineTracker™. Considering pairs of before and after snapshots in different positions (standing, sitting, and bending), we introduce a feature space, that allows for unsupervised clustering. We show that resulting clusters represent certain groups of postural changes, which are meaningful to professional posture trainers.


Assuntos
Dor Lombar/reabilitação , Monitorização Fisiológica , Postura/fisiologia , Dispositivos Eletrônicos Vestíveis , Feminino , Humanos , Dor Lombar/fisiopatologia , Masculino , Movimento (Física) , Coluna Vertebral/fisiologia
19.
Metab Eng ; 48: 13-24, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29753069

RESUMO

Microbial processes can produce a wide range of compounds; however, producing complex and long chain hydrocarbons remains a challenge. Aldol condensation offers a direct route to synthesize these challenging chemistries and can be catalyzed by microbes using aldolases. Deoxyribose-5-phosphate aldolase (DERA) condenses aldehydes and/or ketones to ß-hydroxyaldehydes, which can be further converted to value-added chemicals such as a precursor to cholesterol-lowering drugs. Here, we implement a short, aldolase-based pathway in Escherichia coli to produce (R)-1,3-BDO from glucose, an essential component of pharmaceutical products and cosmetics. First, we expressed a three step heterologous pathway from pyruvate to produce 0.3 g/L of (R)-1,3-BDO with a yield of 11.2 mg/g of glucose in wild-type E. coli K12 MG1655. We used a systems metabolic engineering approach to improve (R)-1,3-BDO titer and yield by: 1) identifying and reducing major by-products: ethanol, acetoin, and 2,3-butanediol; 2) increasing pathway flux through DERA to reduce accumulation of toxic acetaldehyde. We then implemented a two-stage fermentation process to improve (R)-1,3-BDO titer by 8-fold to 2.4 g/L and yield by 5-fold to 56 mg/g of glucose (11% of maximum theoretical yield) in strain BD24, by controlling pH to 7 and higher dissolved oxygen level. Furthermore, this study highlights the potential of the aldolase chemistry to synthesize diverse products directly from renewable resources in microbes.


Assuntos
Butileno Glicóis/metabolismo , Escherichia coli K12 , Proteínas de Escherichia coli , Frutose-Bifosfato Aldolase , Engenharia Metabólica , Escherichia coli K12/enzimologia , Escherichia coli K12/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Frutose-Bifosfato Aldolase/genética , Frutose-Bifosfato Aldolase/metabolismo
20.
Eur Spine J ; 27(4): 847-850, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29305658

RESUMO

OBJECTIVE: Kyphoplasty and vertebroplasty have become one of the most frequent surgical procedures in the treatment of vertebral compression fractures. Often, the cause of compression fractures is lowered bone mineral density as in osteoporosis. In the differential workup, also pathologic vertebral compression fractures need to be ruled out. Importantly, imaging techniques alone cannot safely differentiate between invasive lymphatic and osteoporotic vertebral fracture. Our goal was to identify the degree of unexpected positive histology in kyphoplasty for presumed osteoporotic vertebral compression fracture. METHODS: We retrospectively analyzed all kyphoplasties performed between 2007 and 2015 at our institution. The data were acquired by reviewing our medical documentation system. The data analysis was done using Microsoft Excel. The statistical analysis was done using the Chi-squared test. RESULTS: We performed 130 kyphoplasties/vertebroplasties. A biopsy was taken in 97 (74.6%) cases. In 10 (10.3%) cases, the histology revealed a pathological fracture. From these patients, only in 3 (30%) cases, a positive histology was not expected. Meaning that there was no history of cancer and the radiological findings presumed an osteoporotic fracture. CONCLUSIONS: Therefore, we could demonstrate that the incidence of unexpected positive histology in vertebral compression fracture treated with kyphoplasty is significant (3.1%). As a conclusion, if a kyphoplasty is performed due to assumed osteoporotic vertebral compression fracture, a biopsy should be taken to safely rule out a pathological fracture caused by lymphatic bony invasion.


Assuntos
Fraturas por Compressão/cirurgia , Fraturas Espontâneas/diagnóstico , Cifoplastia/estatística & dados numéricos , Fraturas por Osteoporose/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Neoplasias da Coluna Vertebral/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas Espontâneas/epidemiologia , Fraturas Espontâneas/etiologia , Humanos , Incidência , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/diagnóstico , Estudos Retrospectivos , Fraturas da Coluna Vertebral/etiologia , Neoplasias da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/epidemiologia , Coluna Vertebral/patologia , Coluna Vertebral/cirurgia , Adulto Jovem
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