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1.
Chembiochem ; : e202400540, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39218789

RESUMEN

Mechanosensitive channel MscCG2 is involved in glutamate excretion in most C. glutamicum strains. Improving the excretion efficiency of MscCG2 is beneficial to the production of glutamate. In this study, structure-based rational design was carried out to obtain an improved efflux ability of exporter MscCG2 and its mechanistic advance via two strategies: widening the channel entrance for smoother entry of glutamate and reducing the electronegativity at the entrance of the channels to minimize the rejection of negatively charged glutamate entry. The designed variants were found to enhance glutamate excretion by 2 to 3.3-fold in the early phase and 1.1-fold to 1.5-fold in the late phase of fermentation. The enhanced glutamate excretion was further confirmed by using glutamate toxic analog 4-fluoroglutamate (4-FG) and Glu-Glu peptide uptake and glutamate export assay. Molecular dynamic (MD) simulations revealed that the amino acid substitutions indeed enlarged the channel entrance and reduced the repulsion of glutamate when entering the channel. The finding of this study is important for understanding the underlying structure-function relationship and the mechanism of glutamate secretion to improve glutamate efflux efficiency of glutamate exporter.

2.
FASEB J ; 37(8): e23070, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37389939

RESUMEN

Excessive lipid accumulation is a critical characteristic in the development of nonalcoholic steatohepatitis (NASH). The underlying molecular mechanism, however, is unclear. In this study, we explored whether and how Krüppel-like factor 14 (KLF14) affects hepatic lipid metabolism in NASH. KLF14 expression was detected in NASH patients and mice fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). Adeno-associated viruses and adenoviruses were used to alter hepatic KLF14 expression in vivo or in vitro to investigate how KLF14 functions in lipid regulation. The molecular mechanisms were explored using RNA-seq, luciferase reporter, and ChIP assays. The fatty liver phenotype was analyzed histopathologically, and serum and hepatocyte biochemical parameters were measured. The NASH mouse model developed quickly in C57BL/6J mice fed a CDAHFD for 8 weeks. We found that KLF14 expression was decreased in NASH patients and CDAHFD mice. Oleic acid and palmitic acid treatment also reduced KLF14 levels in hepatocytes. KLF14 knockdown downregulated the genes involved in fatty acid oxidation, promoting the progression of hepatic steatosis. In contrast, hepatic KLF14 overexpression alleviated lipid accumulation and oxidative stress in CDAHFD mice. These effects resulted from direct activation of the PPARα signaling pathway. PPARα inhibition diminished the KLF14 overexpression-reduced protective effects against steatosis in OA&PA-treated MPHs and AAV-KLF14-infected CDAHFD mice. These data reveal that hepatic KLF14 regulates lipid accumulation and oxidative stress through the KLF14-PPARα pathway as NASH progresses. KLF14 may be a novel therapeutic target for hepatic steatosis.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Factores de Transcripción de Tipo Kruppel/genética , Metabolismo de los Lípidos , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/etiología , Ácido Oléico , PPAR alfa/genética
3.
Nature ; 559(7715): 593-598, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-30013119

RESUMEN

Genetically encoded protein scaffolds often serve as templates for the mineralization of biocomposite materials with complex yet highly controlled structural features that span from nanometres to the macroscopic scale1-4. Methods developed to mimic these fabrication capabilities can produce synthetic materials with well defined micro- and macro-sized features, but extending control to the nanoscale remains challenging5,6. DNA nanotechnology can deliver a wide range of customized nanoscale two- and three-dimensional assemblies with controlled sizes and shapes7-11. But although DNA has been used to modulate the morphology of inorganic materials12,13 and DNA nanostructures have served as moulds14,15 and templates16,17, it remains challenging to exploit the potential of DNA nanostructures fully because they require high-ionic-strength solutions to maintain their structure, and this in turn gives rise to surface charging that suppresses the material deposition. Here we report that the Stöber method, widely used for producing silica (silicon dioxide) nanostructures, can be adjusted to overcome this difficulty: when synthesis conditions are such that mineral precursor molecules do not deposit directly but first form clusters, DNA-silica hybrid materials that faithfully replicate the complex geometric information of a wide range of different DNA origami scaffolds are readily obtained. We illustrate this approach using frame-like, curved and porous DNA nanostructures, with one-, two- and three-dimensional complex hierarchical architectures that range in size from 10 to 1,000 nanometres. We also show that after coating with an amorphous silica layer, the thickness of which can be tuned by adjusting the growth time, hybrid structures can be up to ten times tougher than the DNA template while maintaining flexibility. These findings establish our approach as a general method for creating biomimetic silica nanostructures.


Asunto(s)
ADN/química , Nanoestructuras/química , Dióxido de Silicio/química , Biomimética , ADN/ultraestructura , Módulo de Elasticidad , Microscopía Electrónica de Transmisión , Simulación de Dinámica Molecular , Nanoestructuras/ultraestructura
4.
Dig Dis Sci ; 69(1): 56-65, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37943383

RESUMEN

BACKGROUND: The worldwide incidence of acute pancreatitis (AP) is increasing, but the dominant etiology of AP may vary by country. Mixed etiologies are involved in the increase in the number of AP patients. AIMS: This study was to analyze the etiological changes and prognosis of AP patients and explore the prognosis of AP patients with mixed etiologies. METHODS: Using a retrospective analysis method, AP patients hospitalized from January 2007 to December 2021 were selected from a pancreatic center in Nanchang, China. Trends in the main etiologies were analyzed, and the severity and prognosis of different etiologies were compared. RESULTS: A total of 10,071 patients were included. Cholelithiasis (56.0%), hyperlipidemia (25.3%), and alcohol (6.5%) were the top three etiologies. The proportion of acute biliary pancreatitis (ABP) showed a decreasing trend, while the proportion of hypertriglyceridemic pancreatitis (HTGP) and alcoholic AP showed an increasing trend (all ptrend < 0.001). The incidence of organ failure and necrotizing pancreatitis was higher in patients with HTGP than in those with AP induced by other etiologies (all p < 0.05). There was no statistically significant difference in mortality among patients with different etiologies. Patients with AP due to a mixed hypertriglyceridemia-alcoholic etiology had higher ICU admission rates and were more severe than those with AP induced by other mixed etiologies. CONCLUSION: In the past 15 years, the proportion of ABP has trended downward, while those of HTGP and alcoholic AP have risen. Among patients with mixed etiologies, those with a mixed hypertriglyceridemia-alcoholic etiology had a worse prognosis.


Asunto(s)
Hipertrigliceridemia , Pancreatitis Alcohólica , Humanos , Estudios Retrospectivos , Enfermedad Aguda , Hipertrigliceridemia/epidemiología , Pronóstico
5.
Pancreatology ; 23(5): 473-480, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37263836

RESUMEN

BACKGROUND: Acute pancreatitis in pregnancy (APIP) is associated with increased maternal and fetal mortality. OBJECTIVES: We sought to determine whether a low threshold for cesarean section (C-section) in severe acute pancreatitis (SAP) or Predict SAP improves maternal and fetal outcomes in patients with APIP. METHODS: We identified patients with APIP at a single institution from a prospective database and studied fetal and maternal health in APIP before (2005-2014) and after (2015-2019) introduction of multidisciplinary team management with a defined, lowered threshold for C-section. The primary end point was fetal mortality comprising abortion and perinatal death. Risk factors associated with fetal mortality were analyzed by univariable and multivariable logistic regression analysis. RESULTS: A total of 165 patients with APIP were eligible for analysis. There was a highly significant increase in patients undergoing C-section from 37 (30.8%) of 120 during 2005-2014 to 27 (60%) of 45 in 2015-2019 (P = 0.001), with a highly significant fall in fetal mortality from 37 (30.8%) of 120 to 3 (6.7%) of 45 between the same periods (P = 0.001), when maternal mortality fell from 6 to zero (P = 0.19). Maternal early systemic inflammatory response syndrome (SIRS) (odds ratio [OR] 6.98, 95% confidence interval [CI] 1.53, 30.80, P = 0.01) and SAP (OR 3.64, 95%CI 1.25, 10.60, P = 0.02) were two independent risk factors associated with fetal mortality. CONCLUSIONS: Multidisciplinary collaboration and a defined, low threshold for C-section improve fetal outcomes in patients with APIP.


Asunto(s)
Pancreatitis , Embarazo , Humanos , Femenino , Pancreatitis/complicaciones , Cesárea/efectos adversos , Enfermedad Aguda , Grupo de Atención al Paciente
6.
Microb Cell Fact ; 22(1): 161, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37612753

RESUMEN

Regulation of amino acid's biosynthetic pathway is of significant importance to maintain homeostasis and cell functions. Amino acids regulate their biosynthetic pathway by end-product feedback inhibition of enzymes catalyzing committed steps of a pathway. Discovery of new feedback resistant enzyme variants to enhance industrial production of amino acids is a key objective in industrial biotechnology. Deregulation of feedback inhibition has been achieved for various enzymes using in vitro and in silico mutagenesis techniques. As enzyme's function, its substrate binding capacity, catalysis activity, regulation and stability are dependent on its structural characteristics, here, we provide detailed structural analysis of all feedback sensitive enzyme targets in amino acid biosynthetic pathways. Current review summarizes information regarding structural characteristics of various enzyme targets and effect of mutations on their structures and functions especially in terms of deregulation of feedback inhibition. Furthermore, applicability of various experimental as well as computational mutagenesis techniques to accomplish feedback resistance has also been discussed in detail to have an insight into various aspects of research work reported in this particular field of study.


Asunto(s)
Aminoácidos , Biotecnología , Retroalimentación , Mutagénesis , Mutación
7.
BMC Gastroenterol ; 23(1): 195, 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37277756

RESUMEN

BACKGROUND: At present, the relationship between severe acute pancreatitis (SAP) and albumin infusion is not clear. We aimed to identify the impact of serum albumin on the prognosis of SAP and the association between albumin infusions and mortality for hypoalbuminemia patients. METHODS: This was a retrospective cohort study that analyzed 1000 patients with SAP who were admitted to the First Affiliated Hospital of Nanchang University between January 2010 and December 2021 using data from a prospectively maintained database. Multivariate logistic regression analysis was conducted to reveal the relationship between serum albumin within 1 week after admission and poor prognosis of SAP. Propensity score matching (PSM) analysis was adopted to evaluate the effect of albumin infusion for hypoalbuminemia patients with SAP. RESULTS: The prevalence of hypoalbuminemia (≤ 30 g/L) was 56.9% within 1 week after admission. Multivariate logistic regression identified that age (OR: 1.02; 95% CI: 1.00-1.04; P = 0.012), serum urea (OR: 1.08; 95% CI: 1.04-1.12; P < 0.001), serum calcium (OR: 0.27; 95% CI: 0.14-0.50; P < 0.001), lowest albumin level within 1 week after admission (OR: 0.93; 95% CI: 0.89-0.97; P = 0.002), and APACHE II score ≥ 15 (OR: 1.73; 95% CI: 1.19-2.51; P = 0.004) were independently associated with mortality. The PSM analysis demonstrated that mortality (OR: 0.52, 95% CI: 0.29-0.92, P = 0.023) was less common in albumin-infused than non-albumin-infused hypoalbuminemia patients. In subgroup analyses, doses > 100 g within 1 week after admission for hypoalbuminemia patients with albumin infusions was associated with lower mortality than doses ≤ 100 g (OR: 0.51, 95% CI: 0.28-0.90, P = 0.020). CONCLUSIONS: Hypoalbuminemia in early-stage SAP is significantly related to poor prognosis. However, albumin infusions could significantly decrease mortality in hypoalbuminemia patients with SAP. Additionally, infusing sufficient albumin within a week after admission may decrease mortality in hypoalbuminemia patients.


Asunto(s)
Hipoalbuminemia , Pancreatitis , Humanos , Pancreatitis/complicaciones , Pancreatitis/tratamiento farmacológico , Estudios Retrospectivos , Enfermedad Aguda , Albúmina Sérica , Pronóstico , Factores de Riesgo
8.
J Pathol ; 257(5): 620-634, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35394061

RESUMEN

Treatment of schwannomas in patients with neurofibromatosis type 2 (NF2) is extremely unsatisfactory, and innovative therapeutic approaches are urgently needed. However, the lack of clinically relevant NF2-associated schwannoma models has severely hampered drug discovery in this rare disease. Here we report the first establishment and characterization of patient-derived xenograft (PDX) and cell line models of NF2-associated schwannoma, which recapitulates the morphological and histopathological features of patient tumors, retain patient NF2 mutations, and maintain gene expression profiles resembling patient tumor profiles with the preservation of multiple key signaling pathways commonly dysregulated in human schwannomas. Using gene expression profiling, we identified elevated PI3K/AKT/mTOR networks in human NF2-associated vestibular schwannomas. Using high-throughput screening of 157 inhibitors targeting the PI3K/AKT/mTOR pathways in vitro, we identified a dozen inhibitors (such as BEZ235, LY2090314, and AZD8055) with significant growth-suppressive effects. Interestingly, we observed that three cell lines displayed differential therapeutic responses to PI3K/AKT/mTOR inhibitors. Furthermore, we demonstrated that two orally bioavailable inhibitors, AZD8055 and PQR309, suppressed NF2-associated schwannoma growth both in vitro and in vivo. In conclusion, our novel patient-derived models of NF2-associated schwannoma closely mimic the phenotypes and genotypes of patient tumors, making them reliable preclinical tools for testing novel personalized therapies. © 2022 The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neurilemoma , Neurofibromatosis 2 , Línea Celular , Xenoinjertos , Humanos , Neurilemoma/tratamiento farmacológico , Neurilemoma/genética , Neurofibromatosis 2/tratamiento farmacológico , Neurofibromatosis 2/genética , Neurofibromatosis 2/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/genética
9.
J Appl Microbiol ; 134(4)2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37061784

RESUMEN

AIMS: This study aimed to functionally identify the potential L-homoserine transporters in Escherichia coli, and to generate the promising beneficial mutants by targeted directed evolution for improving the robustness and efficiency of microbial cell factories. METHODS AND RESULTS: By constructing a series of gene deletion and overexpression strains, L-homoserine tolerance assays revealed that RhtA was an efficient and major L-homoserine exporter in E. coli, whereas RhtB and RhtC exhibited relatively weak transport activities for L-homoserine. Real-time RT-PCR analysis suggested that the expression levels of these three target mRNAs were generally variably enhanced when cells were subjected to L-homoserine stress. Based on in vivo continuous directed evolution and growth-couple selections, three beneficial mutations of RhtA exporter (A22V, P119L, and T235I) with clearly increased tolerance against L-homoserine stress were quickly obtained after two rounds of mutagenesis-selection cycles. L-homoserine export assay revealed that the RhtA mutants exhibited different degrees of improvement in L-homoserine export capacity. Further studies suggested that a combination of these beneficial sites led to synergistic effects on conferring L-homoserine-resistance phenotypes. Moreover, the introduction of RhtA beneficial mutants into the L-homoserine-producing strains could facilitate increased amounts of L-homoserine in the shake-flask fermentation. CONCLUSIONS: In this study, we provided further evidence that RhtA serves as a major L-homoserine exporter in E. coli, and obtained several RhtA beneficial mutants, including A22V, P119L, and T235I that contributed to improving the L-homoserine resistance phenotypes and the production efficiency in microbial chassis.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Homoserina/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Transporte de Membrana/metabolismo , Mutagénesis , Ingeniería Metabólica/métodos
10.
Surg Endosc ; 37(8): 6246-6254, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37188909

RESUMEN

BACKGROUND: There has been great progress in the use of endoscopic ultrasound (EUS)-guided drainage in acute pancreatitis patients using a novel lumen-apposing metal stent (LAMS) in the last decade, but some patients experience bleeding. Our research analyzed the preprocedural risk factors for bleeding. METHODS: From July 13, 2016 to June 23, 2021, we retrospectively analyzed all patients who received endoscopic drainage by the LAMS in our hospital. Univariate and multivariate statistical analyses were used to identify the independent risk factors. We plotted ROC curves based on the independent risk factors. RESULTS: A total of 205 patients were analyzed and 5 patients were excluded. A total of 200 patients were included in our research. Thirty (15%) patients presented with bleeding. In the multivariate analysis, computed tomography severity index score (CTSI) score [odds ratio (OR), 2.66; 95% CI: 1.31-5.38; P = 0.007], positive blood cultures [odds ratio (OR), 5.35; 95% CI: 1.31-21.9; P = 0.02], and Acute Physiology and Chronic Health Evaluation II (APACHE II) score [odds ratio (OR), 1.14; 95% CI: 1. 01-1.29; P = 0.045] were associated with bleeding. The area under the ROC curve of the combined predictive indicator was 0.79. CONCLUSION: Bleeding in endoscopic drainage by the LAMS is significantly associated with the CTSI score, positive blood cultures, and APACHE II score. This result could help clinicians make more appropriate choices.


Asunto(s)
Pancreatitis , Humanos , Estudios Retrospectivos , Pancreatitis/complicaciones , Pancreatitis/cirugía , Enfermedad Aguda , Resultado del Tratamiento , Endosonografía/efectos adversos , Stents/efectos adversos , Drenaje/efectos adversos , Drenaje/métodos , Hemorragia/etiología
11.
Neurosurg Rev ; 46(1): 31, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36595070

RESUMEN

Skull base tumors are challenging to treat because of their deep location, complex anatomy, and close proximity to important blood vessels and nerves. Furthermore, some patients with cranial tumors are found to have aneurysms, but there is no consensus on how to evaluate the impact of aneurysms on surgery and how to handle the lesions safely and effectively. We retrospectively reviewed our database to identify all patients with a skull base tumor treated in the Department of Neurosurgery of Beijing Tiantan Hospital affiliated with Capital Medical University from 2019 to 2021. The records of patients with skull base tumors associated with aneurysms were analyzed. The operative methods and postoperative follow-up information were collected. We analyzed a total of 481 patients with skull base tumors, comprising 224 males and 257 females with a mean age of 48 ± 14 years. Twenty-four patients (24/481, 5.0%) were diagnosed with aneurysms. For eight patients, it was considered necessary to perform aneurysm treatment before or during the tumor resection surgery. For the other 16 patients, the recommendation was to monitor the aneurysm or perform elective aneurysm treatment after tumor resection. All patients with both skull base tumors and aneurysms benefited from treatment. No severe postoperative complications occurred. We summarized the final treatment plan for all patients with skull base tumors with aneurysms and proposed a protocol to decrease the surgical risk of patients with skull base tumors associated with aneurysms.


Asunto(s)
Aneurisma , Neoplasias de la Base del Cráneo , Masculino , Femenino , Humanos , Adulto , Persona de Mediana Edad , Neoplasias de la Base del Cráneo/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Base del Cráneo/cirugía
12.
J Elder Abuse Negl ; 35(1): 1-33, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37042040

RESUMEN

Using a mix-method design, we examined participants' willingness to respond to mass marketing scams (MMS). In Experiment 1, we examined the effect of age (young versus older) and letter style ("hot" versus "cold") on the intention to respond. The intention of responding was negatively associated with risk (p < .001) and having at least a high school education was positively associated with perception of benefits (b = .684, p < .001). In Experiment 2, we examined reward sensitivity on the intention to respond by manipulating reward amounts (low versus high) and the presence of an activation fee. The presence of an activation fee decreased intent to contact, but percentages remained high (25.75%). Analyses of qualitative data indicated that risk and benefit were both predicted by perceived self-efficacy. The results indicate that consumers' beliefs about their ability to control the outcomes of future interactions affected how they behaved when provided with MMS materials.


Asunto(s)
Abuso de Ancianos , Anciano , Humanos , Mercadotecnía , Intención
13.
Angew Chem Int Ed Engl ; 62(14): e202218390, 2023 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-36751696

RESUMEN

PETase displays great potential in PET depolymerization. Directed evolution has been limited to engineer PETase due to the lack of high-throughput screening assay. In this study, a novel fluorescence-based high-throughput screening assay employing a newly designed substrate, bis (2-hydroxyethyl) 2-hydroxyterephthalate (termed BHET-OH), was developed for PET hydrolases. The best variant DepoPETase produced 1407-fold more products towards amorphous PET film at 50 °C and showed a 23.3 °C higher Tm value than the PETase WT. DepoPETase enabled complete depolymerization of seven untreated PET wastes and 19.1 g PET waste (0.4 % Wenzyme /WPET ) in liter-scale reactor, suggesting that it is a potential candidate for industrial PET depolymerization processes. The molecular dynamic simulations revealed that the distal substitutions stabilized the loops around the active sites and transmitted the stabilization effect to the active sites through enhancing inter-loop interactions network.


Asunto(s)
Hidrolasas , Tereftalatos Polietilenos , Hidrolasas/metabolismo , Tereftalatos Polietilenos/química , Dominio Catalítico
14.
Curr Issues Mol Biol ; 44(4): 1701-1712, 2022 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-35723375

RESUMEN

Sepsis may induce immunosuppression and result in death. S100A12 can bind to the receptor for advanced glycation end-products (RAGE) and Toll-like receptor (TLR)4 following induction of various inflammatory responses. It is unclear whether S100A12 significantly influences the immune system, which may be associated with sepsis-related mortality. We measured plasma S100A12 levels and cytokine responses (mean ± standard error mean) of lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) after S100A12 inhibition in healthy controls and patients with sepsis on days one and seven. Day one plasma soluble RAGE (sRAGE) and S100A12 levels in patients with sepsis were significantly higher than those in controls (2481.3 ± 295.0 vs. 1273.0 ± 108.2 pg/mL, p < 0.001; 530.3 ± 18.2 vs. 310.1 ± 28.1 pg/mL, p < 0.001, respectively). Day seven plasma S100A12 levels in non-survivors were significantly higher than those in survivors (593.1 ± 12.7 vs. 499.3 ± 23.8 pg/mL, p = 0.002, respectively). In survivors, plasma sRAGE levels were significantly decreased after 6 days (2297.3 ± 320.3 vs. 1530.1 ± 219.1 pg/mL, p = 0.009, respectively), but not in non-survivors. Inhibiting S100A12 increased the production of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in stimulated PBMCs for both controls and patients. Therefore, S100A12 plays an important role in sepsis pathogenesis. S100A12 may competitively bind to TLR4 and RAGE, resulting in decreased IL-10 and TNF-α production.

15.
Appl Environ Microbiol ; 88(23): e0151822, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36383019

RESUMEN

Xylose, the major component of lignocellulosic biomass, cannot be naturally or efficiently utilized by most microorganisms. Xylose (co)utilization is considered a cornerstone of efficient lignocellulose-based biomanufacturing. We evolved a rapidly xylose-utilizing strain, Cev2-18-5, which showed the highest reported specific growth rate (0.357 h-1) on xylose among plasmid-free Corynebacterium glutamicum strains. A genetically clear chassis strain, CGS15, was correspondingly reconstructed with an efficient glucose-xylose coutilization performance based on comparative genomic analysis and mutation reconstruction. With the introduction of a succinate-producing plasmid, the resulting strain, CGS15-SA1, can efficiently produce 97.1 g/L of succinate with an average productivity of 8.09 g/L/h by simultaneously utilizing glucose and xylose from corn stalk hydrolysate. We further revealed a novel xylose regulatory mechanism mediated by the endogenous transcription factor IpsA with global regulatory effects on C. glutamicum. A synergistic effect on carbon metabolism and energy supply, motivated by three genomic mutations (Psod(C131T)-xylAB, Ptuf(Δ21)-araE, and ipsAC331T), was found to endow C. glutamicum with the efficient xylose utilization and rapid growth phenotype. Overall, this work not only provides promising C. glutamicum chassis strains for a lignocellulosic biorefinery but also enriches the understanding of the xylose regulatory mechanism. IMPORTANCE A novel xylose regulatory mechanism mediated by the transcription factor IpsA was revealed. A synergistic effect on carbon metabolism and energy supply was found to endow C. glutamicum with the efficient xylose utilization and rapid growth phenotype. The new xylose regulatory mechanism enriches the understanding of nonnatural substrate metabolism and encourages exploration new engineering targets for rapid xylose utilization. This work also provides a paradigm to understand and engineer the metabolism of nonnatural renewable substrates for sustainable biomanufacturing.


Asunto(s)
Corynebacterium glutamicum , Corynebacterium glutamicum/metabolismo , Xilosa/metabolismo , Glucosa/metabolismo , Carbono/metabolismo , Succinatos/metabolismo , Factores de Transcripción/genética , Ingeniería Metabólica/métodos
16.
Pancreatology ; 22(2): 175-184, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34876385

RESUMEN

BACKGROUND: The timing of oral refeeding can affect length of stay (LOS) and recovery of acute pancreatitis (AP). However, the optimal timing for oral refeeding is still controversial for AP. This meta-analysis investigated the effects of immediate or early versus delayed oral feeding on mild and moderate AP, regardless of improvement in clinical signs or laboratory indicators. METHODS: This systematic review and meta-analysis of randomized controlled trials (RCTs) based on data from Embase, Cochrane Library, PubMed, Web of science, and CBM before August 2021. Two researchers independently used Stata16 to extract and analyse study data. Random effect model was performed for meta-analysis to calculate the risk ratio (RR) and standardized mean difference (SMD). RESULTS: 8 RCTs were selected, including 748 patients with mild to moderate AP. Patients in IOR (Immediate or early Oral Refeeding) group had less costs [SMD -0.83, 95%CI (-1.17, -0.5), P < 0.001] and shorter LOS [SMD -1.01, 95%CI (-1.17, -0.85), P < 0.001] than the DOR (Delayed Oral Refeeding) group patients. However, there was no difference in mortality [RR 0.54, 95%CI (0.11, 2.62), P = 0.44], pain relapse rate [RR 0.58, 95%CI (0.25, 1.35), P = 0.27], feeding intolerance rate [RR 0.61, 95%CI (0.28, 1.3), P = 0.2], AP progression rate [RR 0.21, 95%CI (0.04, 1.07), P = 0.06] and overall complications rate [RR 0.41, 95%CI (0.17, 1.01), P = 0.05] between the IOR and DOR groups. CONCLUSIONS: Limited data suggest that IOR could reduce LOS and costs without increasing adverse events in mild to moderate AP.


Asunto(s)
Pancreatitis , Humanos , Tiempo de Internación , Pancreatitis/etiología , Recurrencia
17.
PLoS Biol ; 17(4): e3000229, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-31039149

RESUMEN

Hepatitis A virus (HAV), an enigmatic and ancient pathogen, is a major causative agent of acute viral hepatitis worldwide. Although there are effective vaccines, antivirals against HAV infection are still required, especially during fulminant hepatitis outbreaks. A more in-depth understanding of the antigenic characteristics of HAV and the mechanisms of neutralization could aid in the development of rationally designed antiviral drugs targeting HAV. In this paper, 4 new antibodies-F4, F6, F7, and F9-are reported that potently neutralize HAV at 50% neutralizing concentration values (neut50) ranging from 0.1 nM to 0.85 nM. High-resolution cryo-electron microscopy (cryo-EM) structures of HAV bound to F4, F6, F7, and F9, together with results of our previous studies on R10 fragment of antigen binding (Fab)-HAV complex, shed light on the locations and nature of the epitopes recognized by the 5 neutralizing monoclonal antibodies (NAbs). All the epitopes locate within the same patch and are highly conserved. The key structure-activity correlates based on the antigenic sites have been established. Based on the structural data of the single conserved antigenic site and key structure-activity correlates, one promising drug candidate named golvatinib was identified by in silico docking studies. Cell-based antiviral assays confirmed that golvatinib is capable of blocking HAV infection effectively with a 50% inhibitory concentration (IC50) of approximately 1 µM. These results suggest that the single conserved antigenic site from complete HAV capsid is a good antiviral target and that golvatinib could function as a lead compound for anti-HAV drug development.


Asunto(s)
Anticuerpos Neutralizantes/ultraestructura , Diseño de Fármacos , Virus de la Hepatitis A/inmunología , Aminopiridinas/metabolismo , Aminopiridinas/farmacología , Anticuerpos Monoclonales , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales , Antígenos Virales , Cápside/metabolismo , Simulación por Computador , Epítopos , Antígenos de Hepatitis A/metabolismo , Antígenos de Hepatitis A/ultraestructura , Virus de la Hepatitis A/patogenicidad , Virus de la Hepatitis A/ultraestructura , Humanos , Piperazinas/metabolismo , Piperazinas/farmacología , Unión Proteica
18.
Crit Care ; 26(1): 52, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35241135

RESUMEN

BACKGROUND: Intra-abdominal hypertension (IAH) in acute pancreatitis (AP) is associated with deterioration in organ function. This trial aimed to assess the efficacy of neostigmine for IAH in patients with AP. METHODS: In this single-center, randomized trial, consenting patients with IAH within 2 weeks of AP onset received conventional treatment for 24 h. Patients with sustained intra-abdominal pressure (IAP) ≥ 12 mmHg were randomized to receive intramuscular neostigmine (1 mg every 12 h increased to every 8 h or every 6 h, depending on response) or continue conventional treatment for 7 days. The primary outcome was the percent change of IAP at 24 h after randomization. RESULTS: A total of 80 patients were recruited to neostigmine (n = 40) or conventional treatment (n = 40). There was no significant difference in baseline parameters. The rate of decrease in IAP was significantly faster in the neostigmine group compared to the conventional group by 24 h (median with 25th-75th percentile: -18.7% [- 28.4 to - 4.7%] vs. - 5.4% [- 18.0% to 0], P = 0.017). This effect was more pronounced in patients with baseline IAP ≥ 15 mmHg (P = 0.018). Per-protocol analysis confirmed these results (P = 0.03). Stool volume was consistently higher in the neostigmine group during the 7-day observational period (all P < 0.05). Other secondary outcomes were not significantly different between neostigmine and conventional treatment groups. CONCLUSION: Neostigmine reduced IAP and promoted defecation in patients with AP and IAH. These results warrant a larger, placebo-controlled, double-blind phase III trial. Trial registration Clinical Trial No: NCT02543658 (registered August /27, 2015).


Asunto(s)
Hipertensión Intraabdominal , Pancreatitis , Enfermedad Aguda , Humanos , Hipertensión Intraabdominal/complicaciones , Neostigmina/farmacología , Neostigmina/uso terapéutico , Pancreatitis/complicaciones , Pancreatitis/tratamiento farmacológico
19.
Br J Neurosurg ; 36(6): 756-761, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33423566

RESUMEN

PURPOSE: This study aimed to estimate the prognostic factors, long-term outcomes, and surgical strategies for parasagittal meningioma (PSM) and provide a better understanding of surgical experience. MATERIALS AND METHODS: Patients (n = 1438) who underwent surgery for meningioma between January 2012 and January 2013 were enrolled in a database. We then identified 165 patients with PSM based on this database. RESULTS: Of the 165 patients with identified PSMs, 103 were female and 62 were male, with a mean age of 49 years. Univariate analysis revealed that male sex (p = .002), non-World Health Organization (WHO) grade I meningioma (p < .001), treatment history (p = .006), surgical time more than 232 minutes (p = .006), and intraoperative bleeding > 300mL3 (p = .019) were associated with decreased progression-free survival (PFS). Multivariate analysis revealed that sex (hazards ratio [HR] = 3.836, 95% confidence interval [CI] = 1.364-10.794; p = .011], tumour grade (HR = 8.479, 95% CI = 3.234-22.230; p < .001), and surgical time (HR = 3.710, 95% CI = 1.057-13.023; p = .041) were independent factors for PFS. Patients with Simpson grade I-II (p = .015), no-treatment history (p = .006), tumour size < 3cm (p = .005), surgical time < 232 minutes (p = .019), intraoperative bleeding < 300mL3 (p < .001), or WHO grade I meningioma (p = .002) had better follow-up conditions. CONCLUSION: Surgery was an effective treatment for PSM, and at the time of final follow-up, patients who received aggressive resection had a substantially higher Karnofsky performance scale score.


Asunto(s)
Neoplasias Meníngeas , Meningioma , Humanos , Masculino , Femenino , Persona de Mediana Edad , Meningioma/patología , Neoplasias Meníngeas/cirugía , Neoplasias Meníngeas/patología , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento , Recurrencia Local de Neoplasia
20.
J Sci Food Agric ; 102(2): 716-723, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34171123

RESUMEN

BACKGROUND: The prevalence of diabetes mellitus worldwide has increased in recent decades. Maintaining the level of blood glucose is the most basic and important issue for diabetics. This study aimed to investigate the hypoglycemic activity of a combination of hypoglycemic peptide-enriched hydrolysates of Corbicula fluminea (ACH) and Chlorella sorokiniana (PCH). RESULTS: Combined supplementation of ACH and PCH synergistically inhibited α-glucosidase and DPP4 activities in vitro. After 4 weeks of treatment with ACH and/or PCH, the plasma glucose concentration and insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), total cholesterol (TC) and triglyceride (TG) levels significantly decreased. The hypoglycemic peptides in ACH and PCH were purified and assayed for α-glucosidase and DPP4 activity. The hypoglycemic peptides in ACH and PCH effectively decreased α-glucosidase and DPP4 activities. In silico assays showed that these two peptide types have different docking poses, which determined their inhibitory effect against α-glucosidase and DPP4 activity. CONCLUSION: Combined treatment with hypoglycemic peptide-enriched ACH and PCH could modulate blood glucose by synergistically inhibiting α-glucosidase and DPP4 activities. © 2021 Society of Chemical Industry.


Asunto(s)
Chlorella/química , Corbicula/química , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores de la Dipeptidil-Peptidasa IV/administración & dosificación , Inhibidores de Glicósido Hidrolasas/administración & dosificación , Hipoglucemiantes/administración & dosificación , Péptidos/administración & dosificación , Extractos Vegetales/administración & dosificación , Animales , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/metabolismo , Dipeptidil Peptidasa 4/química , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/química , Sinergismo Farmacológico , Inhibidores de Glicósido Hidrolasas/química , Humanos , Hipoglucemiantes/química , Masculino , Extractos Vegetales/química , Ratas , Ratas Sprague-Dawley , alfa-Glucosidasas/química , alfa-Glucosidasas/metabolismo
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