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1.
Comput Biol Med ; 174: 108439, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38643596

RESUMO

Cholestasis, characterized by the obstruction of bile flow, poses a significant concern in neonates and infants. It can result in jaundice, inadequate weight gain, and liver dysfunction. However, distinguishing between biliary atresia (BA) and non-biliary atresia in these young patients presenting with cholestasis poses a formidable challenge, given the similarity in their clinical manifestations. To this end, our study endeavors to construct a screening model aimed at prognosticating outcomes in cases of BA. Within this study, we introduce a wrapper feature selection model denoted as bWFMVO-SVM-FS, which amalgamates the water flow-based multi-verse optimizer (WFMVO) and support vector machine (SVM) technology. Initially, WFMVO is benchmarked against eleven state-of-the-art algorithms, with its efficiency in searching for optimized feature subsets within the model validated on IEEE CEC 2017 and IEEE CEC 2022 benchmark functions. Subsequently, the developed bWFMVO-SVM-FS model is employed to analyze a cohort of 870 consecutively registered cases of neonates and infants with cholestasis (diagnosed as either BA or non-BA) from Xinhua Hospital and Shanghai Children's Hospital, both affiliated with Shanghai Jiao Tong University. The results underscore the remarkable predictive capacity of the model, achieving an accuracy of 92.639 % and specificity of 88.865 %. Gamma-glutamyl transferase, triangular cord sign, weight, abnormal gallbladder, and stool color emerge as highly correlated with early symptoms in BA infants. Furthermore, leveraging these five significant features enhances the interpretability of the machine learning model's performance outcomes for medical professionals, thereby facilitating more effective clinical decision-making.

2.
Microbiol Res ; 282: 127639, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38354626

RESUMO

Soil salinity negatively affects microbial communities, soil fertility, and agricultural productivity and has become a major agricultural problem worldwide. Plant growth-promoting rhizobacteria (PGPR) with salt tolerance can benefit plant growth under saline conditions and diminish the negative effects of salt stress on plants. In this study, we aimed to understand the salt-tolerance mechanism of Paenibacillus polymyxa at the genetic and metabolic levels and elucidate the mechanism of strain SC2 in promoting maize growth under saline conditions. Under salt stress, we found that strain SC2 promoted maize seedling growth, which was accompanied by a significant upregulation of genes encoding for the biosynthesis of peptidoglycan, polysaccharide, and fatty acid, the metabolism of purine and pyrimidine, and the transport of osmoprotectants such as trehalose, glycine betaine, and K+ in strain SC2. To further enhance the salt resistance of strain SC2, three mutants (SC2-11, SC2-13, and SC2-14) with higher capacities for salt resistance and exopolysaccharide synthesis were obtained via atmospheric and room-temperature plasma mutagenesis. In saline-alkaline soil, the mutants showed better promoting effect on maize seedlings than wild-type SC2. The fresh weight of maize seedlings was increased by 68.10% after treatment with SC2-11 compared with that of the control group. The transcriptome analysis of maize roots demonstrated that SC2 and SC2-11 could induce the upregulation of genes related to the plant hormone signal transduction, starch and sucrose metabolism, reactive oxygen species scavenging, and auxin and ethylene signaling under saline-alkaline stress. In addition, various transcription factors, such as zinc finger proteins, ethylene-responsive-element-binding protein, WRKY, myeloblastosis proteins, basic helix-loop-helix proteins, and NAC proteins, were up-regulated in response to abiotic stress. Moreover, the microbial community composition of maize rhizosphere soil after inoculating with strain SC2 was varied from the one after inoculating with mutant SC2-11. Our results provide new insights into the various genes involved in the salt resistance of strain SC2 and a theoretical basis for utilizing P. polymyxa in saline-alkaline environments.


Assuntos
Paenibacillus polymyxa , Plântula , Plântula/microbiologia , Paenibacillus polymyxa/genética , Zea mays/microbiologia , Solo , Etilenos/metabolismo
3.
Appl Microbiol Biotechnol ; 108(1): 17, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38170316

RESUMO

Polymyxins are cationic peptide antibiotics and regarded as the "final line of defense" against multidrug-resistant bacterial infections. Meanwhile, some polymyxin-resistant strains and the corresponding resistance mechanisms have also been reported. However, the response of the polymyxin-producing strain Paenibacillus polymyxa to polymyxin stress remains unclear. The purpose of this study was to investigate the stress response of gram-positive P. polymyxa SC2 to polymyxin B and to identify functional genes involved in the stress response process. Polymyxin B treatment upregulated the expression of genes related to basal metabolism, transcriptional regulation, transport, and flagella formation and increased intracellular ROS levels, flagellar motility, and biofilm formation in P. polymyxa SC2. Adding magnesium, calcium, and iron alleviated the stress of polymyxin B on P. polymyxa SC2, furthermore, magnesium and calcium could improve the resistance of P. polymyxa SC2 to polymyxin B by promoting biofilm formation. Meanwhile, functional identification of differentially expressed genes indicated that an ABC superfamily transporter YwjA was involved in the stress response to polymyxin B of P. polymyxa SC2. This study provides an important reference for improving the resistance of P. polymyxa to polymyxins and increasing the yield of polymyxins. KEY POINTS: • Phenotypic responses of P. polymyxa to polymyxin B was performed and indicated by RNA-seq • Forming biofilm was a key strategy of P. polymyxa to alleviate polymyxin stress • ABC transporter YwjA was involved in the stress resistance of P. polymyxa to polymyxin B.


Assuntos
Paenibacillus polymyxa , Paenibacillus , Paenibacillus polymyxa/genética , Polimixina B/farmacologia , Polimixina B/metabolismo , Paenibacillus/genética , Paenibacillus/metabolismo , Cálcio/metabolismo , Magnésio , Polimixinas/farmacologia
4.
Microbiol Spectr ; 12(1): e0229323, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38054717

RESUMO

IMPORTANCE: Polymyxins are considered the last line of defense against multidrug-resistant bacteria. The regulatory mechanism of polymyxin synthesis is poorly studied in Paenibacillus polymyxa. In this study, we found that Abh and AbrB3 negatively regulated, whereas Spo0A positively regulated polymyxin synthesis in P. polymyxa SC2. In addition, a regulatory relationship between Abh, AbrB3, and Spo0A was revealed, which regulate polymyxin synthesis via multiple regulatory mechanisms in P. polymyxa.


Assuntos
Paenibacillus polymyxa , Paenibacillus , Polimixinas , Paenibacillus polymyxa/genética , Paenibacillus/genética
5.
J Clin Transl Hepatol ; 11(3): 595-604, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-36969880

RESUMO

Background and Aims: Early identification of prognostic factors to predict transplant/death outcome of biliary atresia (BA) is challenging. We aimed to investigate the longitudinal changes and predictive value of dynamic changes in acoustic radiation force impulse elastography with shear wave speed (SWS) quantification and other parameters within three months after hepatoportoenterostomy (HPE) for 2-year BA outcomes. Methods: Seventy-four patients who underwent HPE between July 2016 and June 2019 were prospectively enrolled. Outcomes were classified into native liver survival and transplant/death groups. Acoustic radiation force impulse elastography was performed sequentially at 3 months intervals post-HPE. Cox regression analysis was used to determine the superior SWS values and other predictors of liver transplantation or death. Results: Among patients 2 years of age, 36 survived with a native liver, nine died, and 29 underwent liver transplantation. The trend in SWS levels in the transplant/death group was significantly different from that in the native liver survival group. ΔSWS at 1-3 months post-HPE and total bilirubin at 1 month post-HPE were selected as superior predictors of liver transplantation or death using multivariate Cox regression models: hazard ratio (HR)=1.927; 95% confidence interval (CI): 1.475-2.661; p<0.001 and HR=1.010; 95% CI: 1.003-1.017; p=0.007, respectively. The combination of the selected ΔSWS and total bilirubin had good predictive power, with an area under the receiver operating characteristics curve of 0.89, specificity 94.44% and sensitivity 73.68%. Conclusions: Our results suggest that early postoperative bilirubin levels and SWS changes were reliable predictors of 2-year BA outcomes.

6.
Physiol Mol Biol Plants ; 28(11-12): 1997-2009, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36573143

RESUMO

Volatile organic compounds (VOCs) have the characteristics of long distance propagation, low concentration, perception, and indirect contact between organisms. In this experiment, Lysinibacillus macroides Xi9 was isolated from cassava residue, and the VOCs produced by this strain were analyzed by the SPME-GC-MS method, mainly including alcohols, esters, and alkanes. By inoculation of L. macroides Xi9, VOCs can promote the growth and change the root-system architecture of Arabidopsis seedlings. The results showed that the number of lateral roots, root density, and fresh weight of Arabidopsis seedlings were significantly higher (p ≤ 0.01), and the number of roots hair was also increased after exposure to strain Xi9. Compared with the control group, the transcriptome analysis of Arabidopsis seedlings treated with strain Xi9 for 5 days revealed a total of 508 genes differentially expressed (p < 0.05). After Gene Ontology enrichment analysis, it was found that genes encoding nitrate transport and assimilation, and the lateral root-related gene ANR1 were up-regulated. The content of NO3 - and amino acid in Arabidopsis seedlings were significantly higher from control group (p ≤ 0.01). Plant cell wall-related EXPA family genes and pectin lyase gene were up-regulated, resulting cell elongation of leaf. SAUR41 and up-regulation of its subfamily members, as well as the down-regulation of auxin efflux carrier protein PILS5 and auxin response factor 20 (ARF20) led to the accumulation of auxin. These results indicated that VOCs of strain Xi9 promote Arabidopsis seedlings growth and development by promoting nitrogen uptake, regulating auxin synthesis, and improving cell wall modification. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01268-3.

7.
Front Microbiol ; 13: 1039806, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483206

RESUMO

The multiple-sugar metabolism regulator (MsmR), a transcription factor belonging to the AraC/XylS family, participates in polysaccharide metabolism and virulence. However, the transcriptional regulatory mechanisms of MsmR1 in Paenibacillus polymyxa remain unclear. In this study, knocking out msmR1 was found to reduce polymyxin synthesis by the SC2-M1 strain. Chromatin immunoprecipitation assay with sequencing (ChIP-seq) revealed that most enriched pathway was that of carbohydrate metabolism. Additionally, electromobility shift assays (EMSA) confirmed the direct interaction between MsmR1 and the promoter regions of oppC3, sucA, sdr3, pepF, yycN, PPSC2_23180, pppL, and ydfp. MsmR1 stimulates polymyxin biosynthesis by directly binding to the promoter regions of oppC3 and sdr3, while also directly regulating sucA and influencing the citrate cycle (TCA cycle). In addition, MsmR1 directly activates pepF and was beneficial for spore and biofilm formation. These results indicated that MsmR1 could regulate carbohydrate and amino acid metabolism, and indirectly affect biological processes such as polymyxin synthesis, biofilm formation, and motility. Moreover, MsmR1 could be autoregulated. Hence, this study expand the current knowledge of MsmR1 and will be beneficial for the application of P. polymyxa SC2 in the biological control against the certain pathogens in pepper.

8.
Biotechnol Biofuels Bioprod ; 15(1): 81, 2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-35953838

RESUMO

BACKGROUND: Paenibacillus polymyxa is a typical plant growth-promoting rhizobacterium (PGPR), and synthesis of indole-3-acetic acid (IAA) is one of the reasons for its growth-promoting capacity. The synthetic pathways of IAA in P. polymyxa must be identified and modified. RESULTS: P. polymyxa SC2 and its spontaneous mutant SC2-M1 could promote plant growth by directly secreting IAA. Through metabonomic and genomic analysis, the genes patA, ilvB3, and fusE in the native IPyA pathway of IAA synthesis in strain SC2-M1 were predicted. A novel strong promoter P04420 was rationally selected, synthetically analyzed, and then evaluated on its ability to express IAA synthetic genes. Co-expression of three genes, patA, ilvB3, and fusE, increased IAA yield by 60% in strain SC2-M1. Furthermore, the heterogeneous gene iaam of the IAM pathway and two heterogeneous IPyA pathways of IAA synthesis were selected to improve the IAA yield of strain SC2-M1. The genes ELJP6_14505, ipdC, and ELJP6_00725 of the entire IPyA pathway from Enterobacter ludwigii JP6 were expressed well by promoter P04420 in strain SC2-M1 and increased IAA yield in the engineered strain SC2-M1 from 13 to 31 µg/mL, which was an increase of 138%. CONCLUSIONS: The results of our study help reveal and enhance the IAA synthesis pathways of P. polymyxa and its future application.

9.
Curr Microbiol ; 79(9): 249, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35834051

RESUMO

Bacillus altitudinis is a widely distributed soil bacterium that has various functional activities, including remediation of contaminated soil, degradation of herbicides, and enhancement of plant growth. B. altitudinis GQYP101 was isolated from the rhizosphere soil of Lycium barbarum L. and demonstrated potential as a plant growth-promoting bacterium. In this work, strain GQYP101 could solubilize phosphorus, and increased the stem diameter, maximum leaf area, and fresh weight of corn in a pot experiment. Nitrogen and phosphorus contents of corn seedlings (aerial part) increased by 100% and 47.9%, respectively, after application of strain GQYP101. Concurrently, nitrogen and phosphorus contents of corn root also increased, by 55.40% and 20.3%, respectively. Furthermore, rhizosphere soil nutrients were altered and the content of available phosphorus increased by 73.2% after application of strain GQYP101. The mechanism by which strain GQYP101 improved plant growth was further investigated by whole genome sequence analysis. Strain GQYP101 comprises a circular chromosome and a linear plasmid. Some key genes of strain GQYP101 were identified that were related to phosphate solubilization, alkaline phosphatase, chemotaxis, and motility. The findings of this study may provide a theoretical basis for strain GQYP101 to enhance crop yield as microbial fertilizer.


Assuntos
Microbiota , Rizosfera , Bacillus , Bactérias/metabolismo , Nitrogênio , Fosfatos/metabolismo , Fósforo , Plântula , Solo/química , Microbiologia do Solo , Zea mays/metabolismo
10.
mSystems ; 7(2): e0142621, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35229649

RESUMO

A novel plant growth-promoting rhizobacterium (PGPR), which was designated strain BY2G20, was isolated from saline-alkaline soil in Dongying, China. Strain BY2G20 can grow at a NaCl range from 0 to 7% and a pH range from 7 to 9 and can prevent the growth of the phytopathogen Ralstonia solanacearum. Based on its phenotypic and genomic characteristics and phylogenetic analysis, strain BY2G20 represents a novel species of the genus Metabacillus, for which the name Metabacillus dongyingensis sp. nov. is proposed. Comparative genomic analysis of strain BY2G20 with its closely related species exhibited a high level of evolutionary plasticity derived by horizontal gene transfer, which facilitated adaptative evolution. Different evolutionary constraints have operated on the diverse functions of BY2G20, with the gene adapted to saline-alkaline ecosystems experiencing functional constraints. We determined the genetic properties of saline-alkaline tolerance and plant growth promotion, such as cation-proton antiporters, cation transporters, osmoprotectant synthesis and transport, H+-transporting F1F0-ATPase, indole-3-acetic acid production, and secondary metabolite synthesis. We also evaluated the effects of strain BY2G20 on the growth of Zea mays L. (maize) under salt stress. The physiological parameters of maize such as plant height, stem diameter, dry biomass, and fresh biomass were significantly higher after inoculating strain BY2G20 under salt stress, indicating that inoculation with BY2G20 enhanced the growth of maize in saline areas. This study demonstrates that M. dongyingensis sp. nov. BY2G20 is a potential candidate for organic agriculture biofertilizers in saline-alkaline areas. IMPORTANCE Plant growth and yield are adversely affected by soil salinity. PGPRs can promote plant growth and enhance plant tolerance to salt stress. In this study, a saline-alkaline tolerant PGPR strain BY2G20 was isolated from the rhizosphere of Ulmus pumila in Dongying, China. Strain BY2G20 represents a novel species within the genus Metabacillus based on phenotypic, genomic, and phylogenetic analysis. Genomic components have undergone different functional constraints, and the disparity in the evolutionary rate may be associated with the adaptation to a specific niche. Genomic analysis revealed numerous adaptive features of strain BY2G20 to a saline-alkaline environment and rhizosphere, especially genes related to salt tolerance, pH adaptability, and plant growth promotion. Our work also exhibited that inoculation of strain BY2G20 enhanced the growth of maize under salt stress. This study demonstrates that PGPRs play an important role in stimulating salt tolerance in plants and can be used as biofertilizers to enhance the growth of crops in saline-alkaline areas.


Assuntos
Solo , Zea mays , Solo/química , Ecossistema , Filogenia , Bactérias/genética , Estresse Salino
11.
Enzyme Microb Technol ; 153: 109957, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34847438

RESUMO

κ-Carrageenan oligosaccharides from κ-carrageenan hydrolysis are important biochemicals with more bioactivity. Enzyme engineering plays a key role in improving κ-carrageenase catalytic efficiency for production of κ-carrageenan oligosaccharides. Effect of metal ions on enzyme activity, especially stability and efficiency, is main factor in catalytic process, but metal ions addition leads to gelation of κ-carrageenan solution. In this study, molecular dynamics simulation was used to explore the interaction between κ-carrageenase CgkPZ and Ca2+, and Ca2+ bonded to D164 and E167 in the catalytic center resulting in the catalytic efficiency increase. Circular dichroism analysis indicated that the secondary structure of κ-carrageenase could change in the presence of Ca2+. Therefore, a novel self-assembly κ-carrageenase-inorganic hybrid nanoflowers CaNF@CgkPZ was synthesized and systematically characterized. The catalytic efficiency (kcat/Km) of CaNF@CgkPZ was 382.1 mL·mg-1·s-1, increased by 292% compared with free κ-carrageenase. Notably, the enzyme activity of CaNF@CgkPZ was not reduced significantly after 19 cycles use, and 70-100% relative activity was still retained when stored at 4-25 â„ƒ for 15 days. This work provides an efficient approach for κ-carrageenase immobilization with good storage stability, reusability and enhanced catalytic efficiency, which is of great significance in practical applications.


Assuntos
Simulação de Dinâmica Molecular , Catálise , Hidrólise
12.
Int J Biol Macromol ; 182: 1473-1483, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34019922

RESUMO

κ-Carrageenan oligosaccharides with many excellent biological properties could be produced by κ-carrageenases selectively. In this study, based on the encoding gene of full length κ-carrageenase obtained from Pseudoalteromonas sp. ZDY3 and the reported mature secreted κ-carrageenase composed of 275 amino acid residues (N26-T300), CgkPZ_GH16 was expressed in E. coli, but no soluble active protein could be detected. Fortunately, the signal peptide of wild-type κ-carrageenase was recognized, and cleaved in the soluble and folding form in E. coli, the Km and kcat values of CgkPZ_SP_GH16 was 1.007 mg/mL and 362.8 s-1. By molecular dynamics simulations, it was showed that YjdB domain might affect the activity of κ-carrageenase. Due to the absence of mature processing modification system in E. coli, YjdB was remained in recombinant full length κ-carrageenase, and the lost catalytic efficiency of CgkPZ was compensated by expression level and thermal stability. Interestingly, CgkPZ_GH16_YjdB was expressed soluble without the signal peptide, which indicated that YjdB could contribute to the expression and folding of κ-carrageenase. These results provide new insight into the effects of different modules of κ-carrageenase on the expression and properties of enzyme.


Assuntos
Proteínas de Bactérias/metabolismo , Escherichia coli/enzimologia , Glicosídeo Hidrolases/metabolismo , Oligossacarídeos/metabolismo , Pseudoalteromonas/enzimologia , Pseudoalteromonas/metabolismo , Proteínas de Bactérias/genética , Glicosídeo Hidrolases/genética
13.
Biotechnol Bioeng ; 118(7): 2597-2608, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33829485

RESUMO

Bacillus coagulans, a thermophilic facultative anaerobe, is a favorable chassis strain for the biosynthesis of desired products. In this study, B. coagulans was converted into an efficient malic acid producer by metabolic engineering and promoter engineering. Promoter mapping revealed that the endogenous promoter Pldh was a tandem promoter. Accordingly, a promoter library was developed, covering a wide range of relative transcription efficiencies with small increments. A reductive tricarboxylic acid pathway was established in B. coagulans by introducing the genes encoding pyruvate carboxylase (pyc), malate dehydrogenase (mdh), and phosphoenolpyruvate carboxykinase (pckA). Five promoters of various strengths within the library were screened to fine-tune the expression of pyc to improve the biosynthesis of malic acid. In addition, genes involved in the competitive metabolic pathways were deleted to focus the substrate and energy flux toward malic acid. Dual-phase fed-batch fermentation was performed to increase the biomass of the strain, further improving the titer of malic acid to 25.5 g/L, with a conversion rate of 0.3 g/g glucose. Our study is a pioneer research using promoter engineering and genetically modified B. coagulans for the biosynthesis of malic acid, providing an effective approach for the industrialized production of desired products using B. coagulans.


Assuntos
Bacillus coagulans , Proteínas de Bactérias , Ciclo do Ácido Cítrico , Malatos/metabolismo , Engenharia Metabólica , Regiões Promotoras Genéticas , Bacillus coagulans/genética , Bacillus coagulans/metabolismo , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética
14.
Transl Pediatr ; 10(2): 225-235, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33708508

RESUMO

BACKGROUND: Distinguishing biliary atresia from non-biliary atresia in patients with cholestasis is challenging, as these conditions have a similar clinical presentation. We developed and externally validated a screening model for biliary atresia and devised a web-based calculator for use in clinical settings. METHODS: A screening model was developed based on data from 227 cholestatic infants (82 and 145 with and without biliary atresia, respectively) and validated in 234 infants (90 and 144 with and without biliary atresia, respectively) admitted to three hospitals. Variables were selected from routine examination results using the least absolute shrinkage and selection operator method and entered into a logistic regression model to construct a biliary-atresia-risk-predicting equation. Cutoff values for risk stratification were estimated using model sensitivity, derived from the receiver-operating characteristic curves. RESULTS: The final screening model included seven variables (i.e., weight at admission, clay-colored stools, γ-glutamyl transpeptidase and albumin levels at admission, abnormal gallbladder, triangular cord sign, and change in total bilirubin levels). The model generated an area under the curve of 0.94 with a sensitivity of 91.46 and specificity of 86.62 in the derivation cohort. This was confirmed in the validation cohort, as we found an area under the curve of 0.93 with a sensitivity of 93.1 and specificity of 80.15. Patients were stratified into three risk groups (low-, moderate-, and high-risk groups). Biliary atresia was excluded in the low-risk group. The high-risk group showed a higher detection rate of biliary atresia compared to the stool color screening method alone. This model was integrated into a user-friendly web-based system. CONCLUSIONS: The screening tool had a high predictive value and may help in decision-making by physicians at tertiary and community hospitals.

15.
Nat Prod Res ; 35(21): 3569-3577, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31951465

RESUMO

Two new alkaloids named Melongenamides H-I (1-2), together with twenty-one known compounds (3-23), were isolated from the 70% ethanol extract of the sepals of Solanum melongena L. The structures of all isolated compounds were determined by 1D and 2D NMR spectra and by comparing their spectroscopic and physical data with values from the published literatures. All the isolated compounds were evaluated the cytotoxicity against three human canner lines (Hela, Ishikawa and MGC-803) by CCK8 assay.


Assuntos
Alcaloides , Solanum melongena , Solanum , Alcaloides/farmacologia , Células HeLa , Humanos , Estrutura Molecular
16.
Protein Expr Purif ; 178: 105768, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33035660

RESUMO

κ-Carrageenase (EC3.2.1.83) is a class of glycoside hydrolase, which can be used for hydrolysis of κ-carrageenan to κ-carrageenan oligosaccharides. In this study, a bacterium, identified as Pseudoalteromonas sp. ZDY3 isolated from rotten algae, was capable to degrade κ-carrageenan. The κ-carrageenase produced by Pseudoalteromonas sp. ZDY3 was purified to homogeneity and named as CgkZDY3. The accurate molecular mass of CgkZDY3 was determined through LC-HRMS, and a posttranslational removal of C-terminal end of the protein was discovered. CgkZDY3 had strict hydrolysis specificity to κ-carrageenan, the values of Km and kcat/Km of CgkZDY3 were 3.67 mg mL-1 and 53.0 mL mg-1 s-1, respectively. CgkZDY3 was a cold-adapted κ-carrageenase with excellent storage stability of both the temperature below 35 °C and a wide pH range, and was an endo-type κ-carrageenase with high hydrolysis rate, oligosaccharides with different degrees of polymerization can be obtained by controlling the hydrolysis time, and the final products were κ-neocarrabiose and κ-neocarratetraose. These properties are of great significance for production of κ-carrageenan oligosaccharides with different polymerization degrees under process control.


Assuntos
Aclimatação , Proteínas de Bactérias , Pseudoalteromonas/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Temperatura Baixa , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/isolamento & purificação
17.
Ann Hepatol ; 23: 100286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33189910

RESUMO

INTRODUCTION AND OBJECTIVES: Differentiating biliary atresia from other causes of neonatal cholestasis is challenging, particularly when cytomegalovirus (CMV) and biliary atresia occur simultaneously. We aimed to elucidate whether CMV infection would affect the differential diagnosis of biliary atresia and intrahepatic cholestasis. PATIENTS AND METHODS: This retrospective study was conducted among patients with neonatal cholestasis admitted to three tertiary hospitals between January 2010 and August 2019. The clinical characteristics, laboratory, and imaging findings were recorded. On the basis of the CMV serology results, the infants were classified into CMV-IgM (+) and CMV-IgM (-) groups. The clinical differences and diagnostic performances of routine predictors between biliary atresia and intrahepatic cholestasis were analyzed in each group. Finally, we compared the diagnostic performances of various tests in the two groups. RESULTS: A total of 705 patients with neonatal cholestasis were enrolled: 215 (30.5%) patients were positive for CMV-IgM, among whom 97 had biliary atresia and 118 had CMV hepatitis; 490 infants were CMV-IgM (-), among whom 240 had biliary atresia and 250 had intrahepatic cholestasis. The diagnostic performances of stool color, direct bilirubin level, γ-glutamyl transpeptidase level, abnormal gallbladder, triangular cord sign, and hepatobiliary scintigraphy between CMV hepatitis and CMV-IgM (+) biliary atresia were similar to those between CMV-IgM (-) biliary atresia and CMV-IgM (-) intrahepatic cholestasis groups. CONCLUSIONS: Our large-scale study showed a high prevalence of CMV infection in patients with neonatal cholestasis in China. The presence of CMV infection did not affect the routine predictors to discriminate biliary atresia and intrahepatic cholestasis.


Assuntos
Atresia Biliar/diagnóstico , Atresia Biliar/microbiologia , Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/microbiologia , Infecções por Citomegalovirus/epidemiologia , Atresia Biliar/complicações , China , Colestase Intra-Hepática/complicações , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico , Diagnóstico Diferencial , Feminino , Humanos , Recém-Nascido , Masculino , Prevalência , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
BMC Pediatr ; 20(1): 364, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32741368

RESUMO

BACKGROUND: Evidence of hand, foot, and mouth disease (HFMD) in neonates is limited. The aim of this study was to evaluate the clinical symptoms, pathogens, possible transmission routes, and prognosis of neonatal HFMD in Shanghai. METHODS: This was a case-control study based on the HFMD registry surveillance system. All neonates and infected family members were enrolled between 2016 and 2017 in Shanghai. Neonates with HFMD were followed for at least half a year. Detailed questionnaires, medical history, and physical examination were recorded. Routine blood examination, liver and renal function, immunophenotypes of peripheral blood lymphocytes (CD3, CD4, and CD8 T-cells; NK cells), immunoglobulin (Ig) M, IgG, and IgA, and cytokine interleukin (IL-1ß, IL-2R, IL-6, IL-8, IL-10, and TNF-α) levels were measured. All rectal swab specimens were collected and genotyped for enterovirus, and phylogenetic analysis based on the VP1 sequences of coxsackievirus A6 (CV-A6) was performed to investigate molecular and evolutionary characteristics. T-test or nonparametric test was used to evaluate the differences. Logistic analysis was applied to calculate the risk of clinical manifestations in the group of HFMD neonates and their paired siblings. RESULTS: There were 16 neonates among the 12,608 diagnosed patients with HFMD, accounting for 0.13%. All neonatal infections were transmitted by other members of the family, mainly the elder siblings, and were caused by CV-A6. CV-A6 was the emerging and predominant causative agent of HFMD in Shanghai. None of the neonates with HFMD experienced fever, onychomadesis, or severe complications. However, two elder sibling patients showed lethargy, and one developed hypoperfusion. In the elder siblings with HFMD, the proportion of white blood cells was generally higher than in neonates with HFMD. The immunologic function of the neonates with HFMD was basically normal. The levels of inflammatory markers were higher in both neonates and elder siblings with HFMD compared to age-matched controls. The clinical symptoms receded about 1 week after onset. None of the neonates had sequelae. CONCLUSIONS: In our study, CV-A6 infection in neonates was benign, but had the character of family clustering. Due to the two-child policy in China, elder siblings may be the main route of HFMD transmission.


Assuntos
Enterovirus , Doença de Mão, Pé e Boca , Idoso , Estudos de Casos e Controles , Criança , China/epidemiologia , Enterovirus/genética , Doença de Mão, Pé e Boca/diagnóstico , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Recém-Nascido , Filogenia
19.
BMC Pediatr ; 20(1): 255, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460787

RESUMO

BACKGROUND: Early distinguishing biliary atresia from other causes of infantile cholestasis remains a major challenge. We aimed to develop and validate a scoring system based on bile acid for identification of biliary atresia. METHODS: In a prospective study, a total of 141 infants with cholestasis were enrolled in two sets (derivation cohort, n = 66; validation cohort, n = 75) from 2014 to 2018. Variables with significant difference between biliary atresia and non-biliary atresia infants were selected in the derivation cohort. Then, a scoring system including those variables was designed and validated. RESULTS: Among 66 patients in the derivation cohort, 34 (51.5%) had biliary atresia. A scoring system was proposed with the following variables: glycochenodeoxycholic acid/chenodeoxycholic acid, clay stool, and gamma-glutamyl transferase. The total score ranged from 0 to 41, and a cutoff value of 15 identified biliary atresia with an area under receiver operating characteristic curve of 0.87 (95% confidence interval, 0.77-0.94), sensitivity of 85.3%, and specificity of 81.3% in the derivation cohort; these values were also confirmed in a validation cohort with a sensitivity of 90.0% and specificity of 80.0%. CONCLUSIONS: The proposed simple scoring system had good diagnostic accuracy for estimating the risk of biliary atresia in infants with cholestasis.


Assuntos
Atresia Biliar , Colestase , Ácidos e Sais Biliares , Atresia Biliar/diagnóstico , Colestase/diagnóstico , Colestase/etiologia , Humanos , Lactente , Estudos Prospectivos , gama-Glutamiltransferase
20.
Front Pediatr ; 8: 131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32296668

RESUMO

Background: Several non-invasive markers have been reported as being effective for the assessment of fibrosis in adults with chronic viral hepatitis. The infantile liver is more susceptible to cholestasis, and it is important to promptly evaluate liver fibrosis to guide the clinical treatment. However, the clinical value of these markers in infants with cholestasis remains unknown. Aim: To investigate the correlation between serum laminin (LN), hyaluronic acid (HA), procollagen III N-terminal peptide (PIIINP) level, and liver fibrosis stage in infants with cholestasis. Methods: One hundred and thirty-seven term infants with cholestasis were included. Laparoscopic exploration and cholangiography were performed to diagnose or rule out biliary atresia. Serum LN, HA, and PIIINP were measured prior to laparoscopic exploration. Liver biopsy was performed for all patients. Liver fibrosis was staged on a five-point scale (F0-F4) according to the METAVIR scoring system. The correlation between serum markers and liver fibrosis stage was assessed. A receiver operator characteristic analysis was performed to determine the accuracy of serum markers for predicting the liver fibrosis stage. Results: Serum PIIINP and HA were positively correlated with liver fibrosis stage (r = 0.622, P < 0.001, and r = 0.41, P < 0.001, respectively). There was no significant correlation between serum LN and liver fibrosis stage (P > 0.05). Serum aspartate aminotransferase, total bilirubin, direct bilirubin, and PIIINP were independently correlated with the fibrosis stage on multivariate ordinal regression analysis. Receiver operating curve (ROC) analysis showed that serum PIIINP was the most effective for the diagnosis of fibrosis grade. The area under the ROC curves (AUROCs) for serum PIIINP for diagnosing fibrosis stages ≥F1, ≥F2, ≥F3, and F4 (cirrhosis) were 0.843, 0.789, 0.82, and 0.891, respectively. The cut-off serum PIIINP value for predicting fibrosis stage ≥F1 was 242.3 ng/mL, with 73.8% sensitivity and 90% specificity. The cut-off value for predicting cirrhosis was 698.7 ng/mL, with 75% sensitivity and 96% specificity. Conclusion: Serum PIIINP is a promising biomarker for predicting liver fibrosis stage, especially cirrhosis. Its assessment is a simple and non-invasive diagnostic method for liver fibrosis in infants with cholestasis.

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