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1.
Appl Opt ; 58(18): 4835-4845, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31503798

RESUMO

The imaging quality of an airborne infrared (IR) system is limited by the angular disturbance of the airborne platform. Based on the full-chain (IR scene-atmosphere-optical system-detector-airborne platform) signal transmission process, this study focused on the low-frequency sinusoidal angular disturbance features of the airborne platform and accurately calculated the point spread function caused by the angular disturbance and the IR imaging features when the IR system's different locations were dynamically simulated in a three-dimensional scene. First, the degradation mechanism of the IR imaging features resulting from the angular disturbance was analyzed from the viewpoint of scene radiation signal transmission and detector sampling. Then, the dynamic simulation in the three-dimensional scene resulting from the angular disturbance was realized by considering the geometric transformation of the spatial imaging, scale registration of the spatial sampling, radiation coupling, and angular disturbance caused by the airborne platform. Finally, the distances detected under different disturbance conditions were predicted using the established model. The obtained results provide data supporting the demonstration, verification, and optimization of the IR imaging system's design scheme.

2.
Crit Rev Biotechnol ; 39(5): 633-647, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31055970

RESUMO

l-Leucine, as an essential branched-chain amino acid for humans and animals, has recently been attracting much attention because of its potential for a fast-growing market demand. The applicability ranges from flavor enhancers, animal feed additives and ingredients in cosmetic to specialty nutrients in pharmaceutical and medical fields. Microbial fermentation is the major method for producing l-leucine by using Escherichia coli and Corynebacterium glutamicum as host bacteria. This review gives an overview of the metabolic pathway of l-leucine (i.e. production, import and export systems) and highlights the main regulatory mechanisms of operons in E. coli and C. glutamicum l-leucine biosynthesis. We summarize here the current trends in metabolic engineering techniques and strategies for manipulating l-leucine producing strains. Finally, future perspectives to construct industrially advantageous strains are considered with respect to recent advances in biology.


Assuntos
Corynebacterium glutamicum/metabolismo , Escherichia coli/metabolismo , Leucina/biossíntese , Corynebacterium glutamicum/genética , Escherichia coli/genética , Leucina/genética , Engenharia Metabólica , Óperon
3.
J Ind Microbiol Biotechnol ; 46(7): 937-949, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30937555

RESUMO

Traditional amino acid producers typically exhibit the low glucose uptake rate and growth deficiency, resulting in a long fermentation time because of the accumulation of side mutations in breeding of strains. In this study, we demonstrate that the efficiency of L-lysine production in traditional L-lysine producer Corynebacterium glutamicum ZL-9 can be improved by rationally engineering glucose uptake systems. To do this, different bypasses for glucose uptake were investigated to reveal the best glucose uptake system for L-lysine production in traditional L-lysine producer. This study showed that overexpression of the key genes in PTSGlc or non-PTSGlc increased the glucose consumption, growth rate, and L-lysine production. However, increasing the function of PTSGlc in glucose uptake led to the increase of by-products, especially for plasmid-mediated expression system. Increasing the participation of non-PTSGlc in glucose utilization showed the best glucose uptake system for L-lysine production. The final strain ZL-92 with increasing the expression level of iolT1, iolT2 and ppgK could produce 201.6 ± 13.8 g/L of L-lysine with a productivity of 5.04 g/L/h and carbon yield of 0.65 g/(g glucose) in fed-batch culture. This is the first report of a rational modification of glucose uptake systems that improve the efficiency of L-lysine production through increasing the participation of non-PTSGlc in glucose utilization in traditional L-lysine producer. Similar strategies can be also used for producing other amino acids or their derivatives.


Assuntos
Corynebacterium glutamicum/metabolismo , Glucose/metabolismo , Lisina/biossíntese , Técnicas de Cultura Celular por Lotes , Transporte Biológico , Corynebacterium glutamicum/genética , Engenharia Metabólica/métodos
4.
Int J Mol Sci ; 20(8)2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022947

RESUMO

The production of l-leucine was improved by the disruption of ltbR encoding transcriptional regulator and overexpression of the key genes (leuAilvBNCE) of the l-leucine biosynthesis pathway in Corynebacterium glutamicum XQ-9. In order to improve l-leucine production, we rationally engineered C. glutamicum to enhance l-leucine production, by improving the redox flux. On the basis of this, we manipulated the redox state of the cells by mutating the coenzyme-binding domains of acetohydroxyacid isomeroreductase encoded by ilvC, inserting NAD-specific leucine dehydrogenase, encoded by leuDH from Lysinibacillus sphaericus, and glutamate dehydrogenase encoded by rocG from Bacillus subtilis, instead of endogenous branched-chain amino acid transaminase and glutamate dehydrogenase, respectively. The yield of l-leucine reached 22.62 ± 0.17 g·L-1 by strain ΔLtbR-acetohydroxyacid isomeroreductase (AHAIR)M/ABNCME, and the concentrations of the by-products (l-valine and l-alanine) increased, compared to the strain ΔLtbR/ABNCE. Strain ΔLtbR-AHAIRMLeuDH/ABNCMLDH accumulated 22.87±0.31 g·L-1 l-leucine, but showed a drastically low l-valine accumulation (from 8.06 ± 0.35 g·L-1 to 2.72 ± 0.11 g·L-1), in comparison to strain ΔLtbR-AHAIRM/ABNCME, which indicated that LeuDH has much specificity for l-leucine synthesis but not for l-valine synthesis. Subsequently, the resultant strain ΔLtbR-AHAIRMLeuDHRocG/ABNCMLDH accumulated 23.31 ± 0.24 g·L-1 l-leucine with a glucose conversion efficiency of 0.191 g·g-1.


Assuntos
Vias Biossintéticas , Corynebacterium glutamicum/genética , Leucina/genética , Engenharia Metabólica/métodos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Corynebacterium glutamicum/metabolismo , Desidrogenase de Glutamato (NADP+)/genética , Desidrogenase de Glutamato (NADP+)/metabolismo , Cetol-Ácido Redutoisomerase/genética , Cetol-Ácido Redutoisomerase/metabolismo , Leucina/metabolismo , Leucina Desidrogenase/genética , Leucina Desidrogenase/metabolismo , Oxirredução
5.
Appl Opt ; 58(7): 1691-1698, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30874200

RESUMO

In view of the optical detection requirements of wide-area and continuous surveillance of air targets, the detection ability of an infrared imaging system in geostationary orbit for aircraft plumes is studied. The point spread model of the subpixel imaging of the full chain, including the aircraft plume, the sea surface, the environmental atmosphere, the optical system, and the imaging detector is established. The detection ability of the typical imaging system in geostationary orbit is analyzed from the signal-to-noise ratio (SNR) and the detection range in combination with the effect of the point spread function (PSF) of the optical system. Meanwhile, the optimal coupling condition of the PSF to the spatial resolution is discussed. The imaging characteristics of the aircraft target on the focal plane of the infrared imaging system under different spatial sampling rates are simulated and verified. Research shows that the SNR of the system first increases, and then decreases gradually with an increase of the spatial sampling rate. The detectable range covered by the pixel footprint decreases as the detector size increases. When the detector size is 15, 20, and 30 µm, the target can be detected with a spatial resolution of 200-700, 300-700, and 400-600 m, respectively.

6.
J Invest Surg ; : 1-8, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894039

RESUMO

BACKGROUND: The purpose of this study was to examine the dimensional change of IVC during acute hemorrhage through a volume-controlled acute hemorrhagic shock model in swine. METHODS: Volume-controlled hemorrhage was performed in 10 adult Bama mini pigs. Enhanced CT scan and hemodynamic monitoring were performed when the cumulative blood loss volume reached 0%, 10%, 20%, 30%, and 40%. The transverse diameter (T) and anteroposterior diameter (AP) of IVC were measured in axial images. Hemodynamic parameters were obtained with Pulse Contour Cardiac Output (PiCCO) hemodynamic monitor device. Arterial blood samples were also collected for artery blood gas analysis at each time point. RESULTS: As the blood loss volume increased, the collapsibility (T/AP) and cross section area (CSA) of IVC significantly changed first in hepatic level and pre-renal level. The significant decrease of the CSA of IVC (shrink) occurred early when the blood loss volume reached only 10%, but the collapse of IVC occurred until the blood loss volume reached 30%. CONCLUSIONS: IVC shrank early but collapsed late during the acute hemorrhage in swine. The finding of collapsed IVC on CT scans suggested severe hypovolemic shock. Evaluation of the IVC at the CT scans can be an adjunctive test of the hemodynamic status in trauma patients.

7.
Sci Rep ; 9(1): 2423, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787467

RESUMO

Dehydrogenase pathway, one of diaminopimelate pathway, is important to the biosynthesis of L-lysine and peptidoglycan via one single reaction catalyzed by meso-diaminopimelate dehydrogenase (DapDH). In this study, the thermostable DapDH was introduced into diaminopimelate pathway that increased the final titer (from 71.8 to 119.5 g/L), carbon yield (from 35.3% to 49.1%) and productivity (from 1.80 to 2.99 g/(L∙h)) of L-lysine by LATR12-2∆rpiB::ddhSt in fed-batch fermentation. To do this, the kinetic properties and the effects of different DapDHs on L-lysine production were investigated, and the results indicated that overexpression of StDapDH in LATR12-2 was beneficial to construct an L-lysine producer with good productive performance because it exhibited the best of kinetic characteristics and optimal temperature as well as thermostability in reductive amination. Furthermore, ammonium availability was optimized, and found that 20 g/L of (NH4)2SO4 was the optimal ammonium concentration for improving the efficiency of L-lysine production by LATR12-2∆rpiB::ddhSt. Metabolomics analysis showed that introducing the StDapDH significantly enhanced carbon flux into pentose phosphate pathway and L-lysine biosynthetic pathway, thus increasing the levels of NADPH and precursors for L-lysine biosynthesis. This is the first report of a rational modification of diaminopimelate pathway that improves the efficiency of L-lysine production through overexpression of thermostable DapDH in E. coli.

8.
Ying Yong Sheng Tai Xue Bao ; 29(12): 4239-4247, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30584753

RESUMO

Elevated atmospheric CO2 has imperceptible impacts on carbon cycle in aquatic ecosystems. However, it remains a question how this process will impact nitrogen cycle that is naturally coupled with carbon cycle. The nitrification and denitrification are two critical processes in the nitrogen cycle. It is reasonable to expect that elevated atmospheric CO2 will influence both processes. We reviewed the previous literatures concerning the effects of elevated atmospheric CO2 on the physico-chemical properties, nitrification, denitrification and nitrogen transformation in water bodies. The published results revealed that the elevated CO2 would reduce the water pH, increase CO2 and HCO3- concentrations, but with different effects on the nitrification and denitrification between eutrophic and oligotrophic water. Elevated atmospheric CO2 could inhibit nitrification and denitrification in oligotrophic water, thereby reduce N2O flux from water. The nitrification process in the eutrophic water bodies was also inhibited, but its denitrification might be promoted by the elevated CO2. In the eutrophic water bodies, there could be an increase of N2O flux when pH was maintained in the range of 7-9. These might eventually result in the accumulation of NH4+ and reduction of NO3- in water, producing an impact on the microbial diversity. Based on these reviews, we proposed some research gaps related to the relevant research fields as well as some scientific questions that is worth to be further explored. This review would be helpful to better understanding on how the greenhouse effect caused by the elevated atmospheric CO2 would affect nitrogen cycle in aquatic ecosystem.


Assuntos
Dióxido de Carbono/análise , Água Doce/química , Ciclo do Nitrogênio , Nitrogênio/análise , Desnitrificação , Nitrificação
9.
Appl Opt ; 57(31): 9499-9507, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30461998

RESUMO

The accurate generation of infrared (IR) imaging features of subpixel targets plays a very important role in the demonstration, verification, and optimization of system design schemes as well as in research into detection algorithms for small targets in the development of remote IR early warning systems. Based on the generation mechanism of target full-link IR imaging features, this study theoretically considers target radiation characteristics, the working environment, and the spatial response and energy-conversion characteristics of IR sensors, and an accurate deduction model of IR imaging features of subpixel targets is proposed and established. First, the surface-radiation field distribution of the target and background are inverted based on the measured data and the model of radiation calibration; then, the accurate simulation of IR imaging features of subpixel targets is realized by considering the geometric transformation of the spatial imaging, the aperiodic transfer function, scale registration of spatial sampling, and radiation coupling. Finally, the accuracy of the proposed model is verified by using the outfield experiment data. The experimental results show that the IR imaging-diffusion features of subpixel targets with different duty cycles are in good agreement with the prediction results of the model. The results obtained provide data support for the demonstration, verification, and optimization of the system design scheme, as well as for research into detection algorithms of small targets in the development of remote IR early warning systems.

10.
Appl Opt ; 57(27): 7691-7701, 2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30462031

RESUMO

In order to establish a more realistic radiation model of the sea surface, the effects of solar radiation, sky radiation, and atmospheric thermal radiation on sea surface radiation are taken into consideration, on the basis of which the infrared radiative transfer equation of the sea surface is deduced in this paper. A method for calculating the bidirectional reflection characteristics of the sea surface based on measured data is proposed according to the projection imaging of beam propagation. Based on the measurements of sea surface temperature, incident sky radiation, incident solar radiation, and radiance of sea crests at different times, the radiative transfer equation is used to retrieve the bidirectional reflectance of a midwave infrared sea surface. Meanwhile, the results of the method mentioned above are compared with the calculated results of Cox-Munk, Mermelstein, Wu, and Beckmann bidirectional reflection characteristics models. Research shows that the bidirectional reflectance at the wave crest of a sea surface increases gradually, when the solar incident zenith angle changes from 56.39° to 76.02° as well as the direction of observation remaining constant (θr=80.0°; ϕr=73.0°). The reflection ability at the wave crest of the sea surface is strongest when the incident direction of the sun is close to the observation direction, which is in accordance with the law of reflection. The Cox-Munk model and Wu model are closer to our values when the solar incidence zenith angle is small (θi≤65.93°). On the other hand, the calculated values of the Mermelstein and Wu models are closer to the values in this paper when the solar incidence zenith angle is large (θi≤65.93°). In general, the error of the Beckmann model is a little greater than that of the other three models.

11.
J Zhejiang Univ Sci B ; 19(10): 739-749, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30269442

RESUMO

Antisense RNA molecule represents a unique type of DNA transcript that comprises 19-23 nucleotides and is complementary to mRNA. Antisense RNAs play the crucial role in regulating gene expression at multiple levels, such as at replication, transcription, and translation. In addition, artificial antisense RNAs can effectively regulate the expression of related genes in host cells. With the development of antisense RNA, investigating the functions of antisense RNAs has emerged as a hot research field. This review summarizes our current understanding of antisense RNAs, particularly of the formation of antisense RNAs and their mechanism of regulating the expression of their target genes. In addition, we detail the effects and applications of antisense RNAs in antivirus and anticancer treatments and in regulating the expression of related genes in plants and microorganisms. This review is intended to highlight the key role of antisense RNA in genetic research and guide new investigators to the study of antisense RNAs.


Assuntos
Pesquisa em Genética , RNA Antissenso/fisiologia , Animais , Antineoplásicos/uso terapêutico , Antivirais/uso terapêutico , Regulação da Expressão Gênica , Humanos , MicroRNAs/fisiologia , RNA Longo não Codificante/fisiologia , RNA Interferente Pequeno/fisiologia
12.
Molecules ; 23(9)2018 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30134636

RESUMO

The production of branched-chain amino acids (BCAAs) is still challenging, therefore we rationally engineered Corynebacterium glutamicum FA-1 to increase the l-leucine production by optimizing the aminotransferases. Based on this, we investigated the effects of the native aminotransferases, i.e., branched-chain amino acid aminotransferase (BCAT; encoded by ilvE) and aspartate aminotransferase (AspB; encoded by aspB) on l-leucine production in C. glutamicum. The strain FA-1△ilvE still exhibited significant growth without leucine addition, while FA-1△ilvE△aspB couldn't, which indicated that AspB also contributes to L-leucine synthesis in vivo and the yield of leucine reached 20.81 ± 0.02 g/L. It is the first time that AspB has been characterized for l-leucine synthesis activity. Subsequently, the aromatic aminotransferase TyrB and the putative aspartate aminotransferases, the aspC, yhdR, ywfG gene products, were cloned, expressed and characterized for leucine synthesis activity in FA-1△ilvE△aspB. Only TyrB was able to synthesize l-leucine and the l-leucine production was 18.55 ± 0.42 g/L. The two putative branched-chain aminotransferase genes, ybgE and CaIlvE, were also cloned and expressed. Both genes products function efficiently in BCAAs biosynthesis. This is the first report of a rational modification of aminotransferase activity that improves the l-leucine production through optimizing the aminotransferases.


Assuntos
Aspartato Aminotransferases/metabolismo , Corynebacterium glutamicum/metabolismo , Leucina/biossíntese , Transaminases/metabolismo , Aminoácidos de Cadeia Ramificada/biossíntese , Aspartato Aminotransferases/genética , Vias Biossintéticas , Corynebacterium glutamicum/genética , Inativação Gênica , Transaminases/genética , Valina/biossíntese
13.
Chin Med Sci J ; 33(2): 69-76, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-29976275

RESUMO

To identify the risk factors that are associated with the midterm coronary artery bypass grafting (CABG) functionality by assessing patency of left internal mammary artery (LIMA) graft and saphenous vein (SV) graft with 64-slice multi-detector computed tomography (64-MDCT).Methods Patients who underwent CABG operation and postoperative 64-MDCT follow-up examinations from August 2012 to December 2015 were included. The graft patent status was classified into patent and poor patent according to MDCT findings predominantly on 3D reconstructed images by two radiologists. The clinical data and imaging findings of the patients were collected and compared between the patent group and poor patent group. Univariate analysis and the multivariate logistic regression analysis were performed to identify the risk factors that affect graft patency.Results Among 341 patients in the study, there were 330 LIMA grafts [326 anastomosed to the left anterior descending artery (LAD), 4 to right coronary artery (RCA)] and 564 SV grafts (SVG) [100 anastomosed to the diagonal branch (D), 226 to the obtuse marginal branch (OM), and 238 to the RCA territory]. The approximal vessel stenosis exceeding 90% occurred in 268 of 292 patent LIMA grafts, and in 1 of 34 poor patent grafts (χ 2=167, P<0.001). The patency rate was higher when SVG was anastomosed to OM (85.4%) or RCA territory (81.9%) than to D (69.0%) (χ 2=15.471, P=0.004). The proximal target vessel stenosis < 90% (OR= 0.015, 95% CI: 0.01-0.14, P=0.000) was independently associated with the closure risk of LIMA grafts, the dyslipidemia (OR= 1.52, 95% CI: 1.0-2.5, P=0.048), history of diabetes (OR = 1.28, 95% CI : 0.90-2.26, P=0.045) and typical angina symptoms (OR=1.81, 95% CI :1.33-4.15, P=0.003) were independently associated with the closure risk of SVG. Conclusions The proximal LAD stenosis less than 90% was adversely associated with graft patency in LIMA recipients; dyslipidemia, diabetes and angina symptoms were associated with the midterm failure in SVG recipients. The choice of the target anastomosis sites may affect the patency of SVG.


Assuntos
Angiografia Coronária/métodos , Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
14.
Ying Yong Sheng Tai Xue Bao ; 29(7): 2355-2361, 2018 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-30039675

RESUMO

Based on dendrochronological methods, we established residual chronologies (RES) of Abies georgei at low, middle and high altitudes with ring width data on the eastern slope of Yulong Snow Mountain. We examined the relationship between the radial growth and climate factors (temperature and precipitation) by response function analysis and redundancy analysis (RDA) to identify the key climatic factors driving the radial growth of A. georgei. The results showed that the responses of radial growth of A. georgei to climates were consistent at three altitudes, which was jointly controlled by temperature and precipitation. This consistency was related to the steep terrain of Yulong Snow Mountain, the high-altitude distribution, and shallow root characteristics of A. georgei. At all three altitudes, tree growth showed significantly positive correlation with mean temperature of the current July, mean temperature of the previous November, and precipitation of the current January, but negative correlation with precipitation of the current June. The comprehensive application of response function analysis and redundancy analysis could accurately reveal the relationship between tree growth and climatic factors along environmental gradients. Our results provided a scientific basis for climatic reconstruction and forest management in the area.


Assuntos
Abies/crescimento & desenvolvimento , Altitude , Clima , China , Neve , Temperatura Ambiente , Árvores
15.
Biotechnol Bioeng ; 115(7): 1764-1777, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29574741

RESUMO

l-lysine is an important amino acid in animals and humans and NADPH is a vital cofactor for maximizing the efficiency of l-lysine fermentation. Dihydrodipicolinate reductase (DHDPR), an NAD(P)H-dependent enzyme, shows a variance in nucleotide-cofactor affinity in bacteria. In this study, we rationally engineered Corynebacterium glutamicum DHDPR (CgDHDPR) to switch its nucleotide-cofactor specificity resulting in an increase in final titer (from 82.6 to 117.3 g L-1 ), carbon yield (from 0.35 to 0.44 g [g glucose]-1 ) and productivity (from 2.07 to 2.93 g L-1 hr-1 ) of l-lysine in JL-6 ΔdapB::Ec-dapBC115G,G116C in fed-batch fermentation. To do this, we comparatively analyzed the characteristics of CgDHDPR and Escherichia coli DHDPR (EcDHDPR), indicating that hetero-expression of NADH-dependent EcDHDPR increased l-lysine production. Subsequently, we rationally modified the conserved structure of cofactor-binding motif, and results indicated that introducing the mutation K11A or R13A in CgDHDPR and introducing the mutation R16A or R39A in EcDHDPR modifies the nucleotide-cofactor affinity of DHDPR. Lastly, the effects of these mutated DHDPRs on l-lysine production were investigated. The highest increase (26.2%) in l-lysine production was observed for JL-6 ΔdapB::Ec-dapBC115G,G116C , followed by JL-6 Cg-dapBC37G,G38C (21.4%) and JL-6 ΔdapB::Ec-dapBC46G,G47C (15.2%). This is the first report of a rational modification of DHDPR that enhances the l-lysine production and yield through the modulation of nucleotide-cofactor specificity.


Assuntos
Coenzimas/metabolismo , Corynebacterium glutamicum/enzimologia , Di-Hidrodipicolinato Redutase/genética , Di-Hidrodipicolinato Redutase/metabolismo , Lisina/metabolismo , Nucleotídeos/metabolismo , Substituição de Aminoácidos , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
16.
Crit Rev Biotechnol ; 38(7): 1061-1076, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29480038

RESUMO

Reduced nicotinamide adenine nucleotide phosphate (NADPH), which is one of the key cofactors in the metabolic network, plays an important role in the biochemical reactions, and physiological function of amino acid-producing strains. The manipulation of NADPH availability and form is an efficient and easy method of redirecting the carbon flux to the amino acid biosynthesis in industrial strains. In this review, we survey the metabolic mode of NADPH. Furthermore, we summarize the research developments in the understanding of the relationship between NADPH metabolism and amino acid biosynthesis. Detailed strategies to manipulate NADPH availability are addressed based on this knowledge. Finally, the uses of NADPH manipulation strategies to enhance the metabolic function of amino acid-producing strains are discussed.


Assuntos
Aminoácidos/metabolismo , Biotecnologia , Engenharia Metabólica , Redes e Vias Metabólicas , NADP/metabolismo , Corynebacterium glutamicum , Escherichia coli
17.
Anticancer Res ; 37(8): 4425-4431, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28739736

RESUMO

BACKGROUND/AIM: Puerarin possesses a battery of therapeutic values in diverse disorders, including pro-apoptotic actions in multiple cancers. Herein, we investigated the effects of puerarin on hepatocellular carcinoma (HCC) in vitro. MATERIALS AND METHODS: MTT and flow cytometry were carried out to evaluate the viability and apoptosis of SMMC-7721 HCC cells in the presence of different concentrations of puerarin. Moreover, expression levels, as well as phosphorylation status of several canonical components in mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinase 1/2 (ERK1/2), c- Jun N-terminal kinase (JNK), p38, were measured by reverse transcription and quantitative real-time polymerase chain reaction (RT-PCR) and western blot analysis at indicated time intervals. RESULTS: Puerarin inhibited proliferation of SMMC-7721 cells and promoted their apoptosis in a dose- and time-dependent fashion (p<0.05). Both the expression and phosphorylation levels of MAPK proteins were dramatically increased on puerarin treatment. CONCLUSION: Puerarin could be employed as a potential anti-carcinogen that exhibits pro-apoptotic effects on HCC cells, in a dose- and time-dependent manner, with emphasis on MAPK pathways whose initiation may contribute to this process.


Assuntos
Carcinoma Hepatocelular/metabolismo , Isoflavonas/farmacologia , Neoplasias Hepáticas/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
18.
J Zhejiang Univ Sci B ; 18(6): 462-473, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28585422

RESUMO

A menaquinone-7 (MK-7) high-producing strain needs to be isolated to increase MK-7 production, in order to meet a requirement of MK-7 given the low MK-7 content in food products. This article focuses on developing MK-7 high-producing strains via screening and mutagenesis by an atmospheric and room temperature plasma (ARTP) mutation breeding system. We isolated an MK-7-producing strain Y-2 and identified it as Bacillus amyloliquefaciens, which produced (7.1±0.5) mg/L of MK-7 with maize meal hydrolysate as carbon source. Then, an MK-7 high-producing strain B. amyloliquefaciens H.ß.D.R.-5 with resistance to 1-hydroxy-2-naphthoic acid, ß-2-thienylalanine, and diphenylamine was obtained from the mutation of the strain Y-2 using an ARTP mutation breeding system. Using strain H.ß.D.R.-5, efficient production of MK-7 was achieved ((30.2±2.7) mg/L). In addition, the effects of nitrogen sources, prenyl alcohols, and MgSO4 on MK-7 production were investigated, suggesting that soymeal extract combined with yeast extract, isopentenol, and MgSO4 was beneficial. Under the optimized condition, the MK-7 production and biomass-specific yield reached (61.3±5.2) mg/L and 2.59 mg/L per OD600 unit respectively in a 7-L fermenter. These results demonstrated that strain H.ß.D.R.-5 has the capacity to produce MK-7 from maize meal hydrolysate, which could reduce the substrate cost.


Assuntos
Bacillus amyloliquefaciens/metabolismo , Vitamina K 2/análogos & derivados , Álcoois/farmacologia , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/isolamento & purificação , Biomassa , Vias Biossintéticas , Biotecnologia , Meios de Cultura , Difenilamina/análogos & derivados , Difenilamina/farmacologia , Farmacorresistência Bacteriana/genética , Fermentação , Microbiologia Industrial , Magnésio/farmacologia , Mutagênese , Nitrogênio/metabolismo , Vitamina K 2/metabolismo , Zea mays/química
19.
Medicine (Baltimore) ; 96(48): e8966, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29310400

RESUMO

RATIONALE: The occurrence of hyperkalemia after esophagectomy is clinically rare. Patients who underwent esophagectomy often have a serum potassium level due to perioperative reduced intake, fluids loss, consumption and other reasons. These patients often require the artificial administration of potassium. Rapid fluid loss and physiological consumption lead to the deficiency of potassium, even hypokalemia. Patients often require the addition of a large amount of potassium after operation. The occurrence of hyperkalemia after esophagectomy is never been reported. PATIENT CONCERNS: The patient presented with continuous tachycardia, palpitations, chest tightness, progressive nausea, irritability, progressive myasthenia gravis. DIAGNOSES: Hyperkalemia, sepsis, acidosis, diabetes, postoperative esophageal cancer. INTERVENTIONS: Prompt anti-infection treatment and the management of blood sugar, hemodialysis was performed to correct sthe acidosis and electrolyte disorder OUTCOMES:: All symptoms were alleviated. LESSONS: Therefore, there is a need to regularly test electrolytes, especially in patients with diabetes, as well as better blood glucose control. Attention should be paid to the potential of infection, and to avoiding ketoacidosis and risk of sepsis.


Assuntos
Esofagectomia , Hiperpotassemia/etiologia , Hiperpotassemia/terapia , Complicações Pós-Operatórias , Idoso , Diagnóstico Diferencial , Neoplasias Esofágicas/cirurgia , Feminino , Humanos , Hiperpotassemia/diagnóstico
20.
J BUON ; 22(6): 1563-1569, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29332353

RESUMO

PURPOSE: The main target of the present research was to examine the antitumor properties of aesculetin in human acute myeloid leukemia cancer cells (THP-1) and peripheral blood mono-nucleated cells (PBMCs) (used as normal cell line model) along with the determination of its effects on induction of apoptosis, inhibition of cancer cell migration and changes in Bcl-2/Bax protein expressions. METHODS: MTT colorimetric bioassay was performed to study the impact of this natural compound on cytotoxicity of both cell types. Moreover, transmission electron microscopy (TEM), inverted phase contrast and fluorescence microscopic techniques were used to study the effects on cell morphology and cellular ultrastructural details connected with apoptosis. The effects of aesculetin on Bcl-2/Bax protein expressions were assessed by Western blot method. RESULTS: Selective and dose-dependent antiproliferative activity of aesculetin in human acute myeloid leukemia cancer cells was observed. However, the compound did not induce significant cell growth inhibition of PBMCs, which were used as normal cell controls. Fluorescence and inverted phase contrast microscopic techniques revealed that aesculetin led to morphological changes suggestive of apoptosis (cell shrinkage, chromatin abridgment and membrane blebbing). TEM analysis showed that aesculetin led to fragmented plasma membrane along with appearance of spherical projections (apoptotic bodies). The wound scratch widened after aesculetin treatment, indicating that aesculetin exhibits anticancer effects by suppressing the cancer cell migration. Aesculetin led to significant and dose-dependent reduction in the Bcl-2 expression while the expression of Bax was significantly enhanced resulting in overall reduction of Bcl-2/Bax ratio. CONCLUSION: The results of the present work revealed that aesculetin exhibits selective anticancer effects in THP-1 human leukemia cells without causing much cytotoxicity in PBMCs. It also led to significant apoptosis induction, inhibition of cancer cell migration and decrease in Blc-2/Bax ratio.


Assuntos
Leucemia Mieloide Aguda/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Umbeliferonas/farmacologia , Proteína X Associada a bcl-2/genética , Apoptose/efeitos dos fármacos , Caspase 3/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/genética
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