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1.
Lasers Med Sci ; 38(1): 277, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38012462

RESUMO

This study aimed to compare higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) in patients with different angle kappa. This is a retrospective report in which 341 right eyes of 341 patients who were subjected to SMILE, which used coaxially sighted corneal light reflex (CSCLR) as the treatment zone centered, treated by the same experienced surgeon (LHB) for correction of myopia and myopic astigmatism, preoperative and postoperative spherical equivalent (SE), angle kappa, total higher-order aberrations (total HOA), spherical aberration (SA), vertical coma (VC), horizontal coma (HC), oblique trefoil (OT), and horizontal trefoil (HT), were compared. SMILE showed outstanding performance in terms of safety, efficacy, and predictability. In addition, a comparison of preoperative and postoperative HOAs exhibited the difference of total HOA (P < 0.01), SA (P < 0.01), VC (P < 0.01), and HC (P < 0.01), which was statistically significant; however, for OT and HT with the longer follow-up time, the statistical difference gradually decreased. For stratification of angle kappa into groups based on decantation, angle kappa was divided into three major groups: r < 0.1 mm, 0.1 ≤ r < 0.2 mm, and r ≥ 0.2 mm; the changes of SA (F = 4.127, P = 0.021) and OT (F = 3.687, P = 0.031) exhibited significant difference after 1 year of SMILE. We performed a correlation analysis of all preoperative and postoperative parameters, and the results indicated that the preoperative total HOA was negatively correlated with preoperative cylindrical diopter (DC), and postoperative total HOA, SA, and coma were affected by spherical diopter (DS) and SE. Moreover, we also found a significant difference of SA and VC in the early postoperative with preoperative. SA was positively correlated with Y values and r of 1 year after SMILE. All of the analyzed parameters in the three groups, except for the trefoil, gradually increased over time; however, the trefoil could gradually stabilize over time. We also divided angle kappa into four groups by quadrants; the result showed that the effects of higher-order aberrations were markedly different from the various quadrants. Patients with large angle kappa were able to increase VC and SA postoperatively, and higher HOAs were more significant in patients with high myopia. The differences in quadrants exhibited a diversity of HOAs; this could be attributed to the corneal surface reestablishment and the alteration of angle kappa, but the trend was not apparent. Although all patients displayed increased HOAs after SMILE, the potential application of CSCLR as the treatment zone centered still showed excellent safety, efficacy, and predictability.


Assuntos
Miopia , Ferida Cirúrgica , Humanos , Acuidade Visual , Estudos Retrospectivos , Coma , Refração Ocular , Miopia/cirurgia , Lasers de Excimer
2.
J Environ Manage ; 316: 115017, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35598448

RESUMO

Seasonal leachate from both sealed and operating landfill in the identical district were employed as the sole substrate in the Microbial Fuel Cell (MFC) to evaluate the power output performance and aqueous organic waste disposal. The electrical performance was characterized to study the power generation, while the Chemical Oxygen Demand (COD) removal ratio and Coulombic Efficiency (CE) were calculated to illustrate the substrate disposal effect. In addition, Scanning Electron Microscope (SEM) on the operated anode was conducted to preliminarily explain the microbial community difference, and the phylogenetic tree constructed on the cultivated microorganism was an insight into the dominant bacteria suitable for leachate degradation. It was found that the MFCs inoculated with seasonal leachate from both sealed and operating landfill could generate electricity successfully. Although the fresh leachate-inoculated MFCs had better electrical output performance (22.7-25.6 W/m3 versus 6.61-7.48 W/m3) and COD removal efficiency (55.8%∼61.7% versus 47.7%∼51.4%), the CEs were only 4.3%∼7.6%, which were lower than the aged leachate inoculated group (5.9%∼11.3%). Based on the SEM images and the phylogenetic tree of the operated anode, the composition impacts on the microbial community and power output performance were verified, which was instructive for the leachate disposal in the MFC.


Assuntos
Fontes de Energia Bioelétrica , Análise da Demanda Biológica de Oxigênio , Eletricidade , Eletrodos , Filogenia
3.
BMC Biotechnol ; 18(1): 27, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29751749

RESUMO

BACKGROUND: As a very important coenzyme in the cell metabolism, Vitamin B12 (cobalamin, VB12) has been widely used in food and medicine fields. The complete biosynthesis of VB12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB12 production. High-yield VB12-producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. RESULT: By the help of engineered strains with varied capacities of VB12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5-2 was obtained and considered as a candidate for industrial applications. After 7 d's cultivation on a rotary shaker at 30 °C, the VB12 titer of S. meliloti MC5-2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5-2 was sequenced, and gene mutations were identified and analyzed. CONCLUSION: To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB12-yield strains.


Assuntos
Proteínas de Bactérias/genética , Engenharia Metabólica/métodos , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/metabolismo , Vitamina B 12/biossíntese , Vitamina B 12/genética , Regulação Bacteriana da Expressão Gênica , Ensaios de Triagem em Larga Escala , Mutagênese , Mutação , Riboswitch
4.
Biotechnol Appl Biochem ; 62(1): 32-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24716991

RESUMO

The presence of the highly toxic furfural and hydroxymethylfurfural (HMF) in the hydrolysate of lignocellulosic biomass prompted the investigation of the Escherichia coli ΔacrR regulatory mutant for higher tolerance to these compounds, to facilitate the production of biofuels and biochemicals, and further biocatalytic conversions. In comparison with the parental strain, the regulatory mutant with the upregulated efflux pump AcrAB-TolC produced moderately better growth and higher tolerance to concentrations of furfural and HMF between 1 and 2 g L(-1) .


Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Furaldeído/análogos & derivados , Deleção de Genes , Proteínas Repressoras/genética , Relação Dose-Resposta a Droga , Escherichia coli/fisiologia , Furaldeído/toxicidade , Hexanos/toxicidade , Proteínas Repressoras/deficiência
5.
Sensors (Basel) ; 14(8): 13730-58, 2014 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-25076222

RESUMO

Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33~2000 pC/N, kt~60%) near the morphotropic phase boundary (MPB). Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals also possess outstanding performance comparable with PMN-PT single crystals, but have higher phase transition temperatures (rhombohedral to tetragonal Trt, and tetragonal to cubic Tc) and larger coercive field Ec. Therefore, these relaxor-based single crystals have been extensively employed for ultrasonic transducer applications. In this paper, an overview of our work and perspectives on using PMN-PT and PIN-PMN-PT single crystals for ultrasonic transducer applications is presented. Various types of single-element ultrasonic transducers, including endoscopic transducers, intravascular transducers, high-frequency and high-temperature transducers fabricated using the PMN-PT and PIN-PMN-PT crystals and their 2-2 and 1-3 composites are reported. Besides, the fabrication and characterization of the array transducers, such as phased array, cylindrical shaped linear array, high-temperature linear array, radial endoscopic array, and annular array, are also addressed.


Assuntos
Nióbio/química , Óxidos/química , Transdutores , Ultrassom/métodos , Cristalização/métodos , Desenho de Equipamento/métodos , Análise de Falha de Equipamento/métodos , Temperatura Alta , Temperatura de Transição
6.
Indian J Ophthalmol ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990627

RESUMO

PURPOSE: To observe the effects of visual neuroplasticity training on visual perception, visual quality, and macular blood flow in patients with concomitant strabismus postoperatively. METHODS: In total, 108 patients underwent binocular strabismus correction operation, and some patients underwent neuroplasticity training. All patients underwent clinical ophthalmic examination, including measurement of best-corrected visual acuity, spherical equivalent, axis length, optical coherence tomography angiography, optical quality analysis system, and visual perception examinations. RESULTS: A total of 78 patients received neuroplasticity training for 1 month postoperatively, and 30 patients did not receive training. All patients underwent a visual perception examination preoperatively and at 1 day, 1 week, and 1 month postoperatively. Macular blood flow and visual quality were examined preoperatively and at 1 month postoperatively. Postoperative visual perception was better than preoperative visual perception (P < 0.05). After neuroplasticity training, the visual perception of the trained subjects was better than that of the untrained subjects (P < 0.05), and the blood flow in the macular area of the trained patients was lower than that of the untrained subjects (P < 0.05). The visual quality of the untrained subjects was lower than that of the trained patients (P < 0.05). CONCLUSIONS: Visual inspection system could accurately evaluate binocular visual perception in patients with concomitant strabismus. After surgical alignment of the strabismus patient, training can stimulate and integrate the formation of stereovision in a short period of time, maintain the visual quality of patients after surgery, and provide conditions for the formation of binocular visual signals and binocular stereovision, but in the short term, it will lead to the decrease of macular blood vessel density and perfusion density. However, the long-term effects of training have not been proven.

7.
Nanomaterials (Basel) ; 14(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38535660

RESUMO

Many studies have been conducted on the microbial reduction of Pd (II) to palladium nanoparticles (Pd-NPs) due to the environmental friendliness, low cost, and the decreased toxicity of Pd (II) ions. In this study, we investigate the reduction mechanism of Pd (II) by Bacillus megaterium Y-4 through proteomics. The data are available via ProteomeXchange with identifier PXD049711. Our results revealed that B. megaterium Y-4 may use the endogenous electron donor (NAD(P)H) generated by nirB, tdh, and fabG and reductase to reduce Pd (II) to Pd-NPs. The expression levels of fabG, tdh, gudB, and rocG that generate NAD(P)H were further increased, and the number of reduced Pd-NPs was further increased with the exogenous electron donor sodium formate. Endogenous electron mediators such as quinones and flavins in B. megaterium Y-4 can further enhance Pd (II) reduction. The findings provided invaluable information regarding the reduction mechanism of Pd (II) by B. megaterium Y-4 at the proteome level.

8.
Int J Biol Macromol ; 281(Pt 1): 136204, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39362426

RESUMO

3-Acetylaconitine (AAC) is a commercially analgesic drug for arthritis, however, due to its narrow safety range, its clinical application is limited. The objective of the study was to investigate the combined effect of Cucumaria frondosa polysaccharide (CFP) and AAC in microneedles on knee osteoarthritis (KOA). The characterization of microneedles was conducted and a rat model of monosodium iodoacetate (MIA)-induced KOA was established to evaluate the anti-inflammatory and analgesic activity in this study. The inhibitory effects on cartilage degradation and synovial inflammation were determined by morphological observation of the knee joint, pathological and imaging results. The von Frey pain threshold and hind limb weight bearing test were used to evaluate the effect of microneedles on pain relief. The results showed that microneedles had the mechanical strength to penetrate the skin and dissolved well in the skin for drug delivery within 30 min after patch administration. Furthermore, AAC-MN and CFP-AAC-MN both played roles in relieving pain, reducing cartilage degeneration and inhibiting synovial inflammation in KOA. In summary, CFP combined with AAC loading into microneedles exhibited higher skin penetration and more advantages in inhibiting cartilage damage and inflammation compared to AAC alone.

9.
Acta Biomater ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39322042

RESUMO

Postoperative adhesions commonly form in various tissues, resulting in serious implications and an increased risk of secondary surgery. The application of anti-adhesion films as physical barriers has proven effective in reducing adhesion incidence and severity. However, existing anti-adhesion films require manual deployment during minimally invasive surgery, posing inconvenience and possibility of further injury. To address these limitations, we have developed an intelligent anti-adhesion film based on shape memory polyurethane. In this work, a linear shape memory polyurethane (ISO2-PU), incorporating hexamethylene isocyanate and isosorbitol as hard segments and poly(D, L-lactic acid) macrodiol as soft segments, was fabricated into an anti-adhesion film. The favorable shape memory effect of the ISO2-PU film ensures its convenient delivery and automatic unfolding, as revealed by a simulation experiment for endoscopic surgical implantation. Furthermore, the glass transition temperature (Tg) close to body temperature endows the ISO2-PU film with good mechanical compliance, thus ensuring a reliable fit with the wounded tissue to avoid undesired folding. Finally, in vivo experiments using a rat cecal abdominal wall injury model demonstrated that the combination of reliable fit, appropriate degradation rate, and good cytocompatibility promises the ISO2-PU film with high anti-adhesion efficacy. This work validates the concept of shape memory anti-adhesion barrier and expands future directions for advanced anti-adhesion biomaterials. STATEMENT OF SIGNIFICANCE: Postoperative adhesions are a common complication that occurs widely after various surgeries. This work developed an intelligent anti-adhesion film based on a linear shape memory polyurethane (ISO2-PU). This film is featured with remarkable shape memory effect and mechanical compliance at body temperature, appropriate degradability, and good cytocompatibility. These merits ensure convenient delivery and smart unfolding of ISO2-PU film during minimally invasive surgery and favorable postoperative anti-adhesion efficacy. The results validate the concept of shape memory anti-adhesion barrier and paves a way for designing next-generation anti-adhesion biomaterials.

10.
Microb Cell Fact ; 12: 106, 2013 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-24219401

RESUMO

BACKGROUND: Failure of colony PCRs in green microalga Chlorella vulgaris is typically attributed to the difficulty in disrupting its notoriously rigid cell walls for releasing the genetic materials and therefore the development of an effective colony PCR procedure in C. vulgaris presents a challenge. RESULTS: Here we identified that colony PCR results were significantly affected by the accumulated lipids rather than the rigid cell walls of C. vulgaris. The higher lipids accumulated in C. vulgaris negatively affects the effective amplification by DNA polymerase. Based on these findings, we established a simple and extremely effective colony PCR procedure in C. vulgaris. By simply pipetting/votexing the pellets of C. vulgaris in 10 ul of either TE (10 mM Tris/1 mM EDTA) or 0.2% SDS buffer at room temperature, followed by the addition of 10 ul of either hexane or Phenol:Chloroform:Isoamyl Alcohol in the same PCR tube for extraction. The resulting aqueous phase was readily PCR-amplified as genomic DNA templates as demonstrated by successful amplification of the nuclear 18S rRNA and the chloroplast rbcL gene. This colony PCR protocol is effective and robust in C. vulgaris and also demonstrates its effectiveness in other Chlorella species. CONCLUSIONS: The accumulated lipids rather than the rigid cell walls of C. vulgaris significantly impede the extraction of genetic materials and subsequently the effective colony PCRs. The finding has the potential to aid the isolation of high-quality total RNAs and mRNAs for transcriptomic studies in addition to the genomic DNA isolation in Chlorella.


Assuntos
Parede Celular/metabolismo , Chlorella vulgaris/genética , Reação em Cadeia da Polimerase/métodos , Parede Celular/genética , Lipídeos/genética
11.
Int J Biol Macromol ; 235: 123853, 2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-36863676

RESUMO

The purpose of this study was to investigate the preventive effects of polysaccharide from Ostrea rivularis (ORP) on high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in mice and the underlying mechanism. The results showed that NAFLD model group mice had significant fatty liver lesions. ORP could significantly reduce TC, TG and LDL level, and increase HDL level in serum of HFD mice. Besides, it could also reduce the contents of serum AST and ALT and alleviate pathological changes of fatty liver disease. ORP could also enhance the intestinal barrier function. 16sRNA analysis showed that ORP could reduce the abundance of Firmicutes and Proteobacteria and the ratio of Firmicutes/ Bacteroidetes at the phylum level. These results suggested that ORP could regulate the composition of gut microbiota in NAFLD mice, enhance intestinal barrier function, reduce intestinal permeability, and finally delay the progress and reduce the occurrence of NAFLD. In brief, ORP is an ideal polysaccharide for prevention and treatment of NAFLD, which can be developed as functional food or candidate drugs.


Assuntos
Crassostrea , Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Ostrea , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/patologia , Fígado , Dieta Hiperlipídica/efeitos adversos , Apolipoproteínas E , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Camundongos Endogâmicos C57BL
12.
J Ethnopharmacol ; 317: 116872, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37393027

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Dalbergia pinnata, as a natural and ethnic medicine in China, has been used for burns and wounds with a long history, which has the effect of invigorating blood and astringent sores. However, there were no reports on the advantage activity of burns. AIM OF STUDY: The purpose of this study was to screen out the best active extract part of Dalbergia pinnata and investigate its therapeutic effect on wound healing and scar resolution. MATERIALS AND METHODS: Rat burn model was established and the healing effects of extracts from Dalbergia pinnata on burn wounds were evaluated by the percentage of wound contraction and period of epithelialization. Histological observation, immunohistochemistry, immunofluorescence and ELISA were used for the examination of inflammatory factors, TGF-ß1, neovascularization and collagen fibers through the period of epithelialization. In addition, the effect of the optimal extraction site on fibroblast cells was evaluated by cell proliferation and cell migration assays. The extracts of Dalbergia pinnata were analyzed by UPLC-Q/TOF-MS or GC-MS technique. RESULTS: Compared to the model group, there were better wound healing, suppressed inflammatory factors, more neovascularization as well as newly formed collagen in the ethyl acetate extract (EAE) and petroleum ether extract (PEE) treatment groups. The ratio of Collagen I and Collagen III was lower in the EAE and PEE treatment groups, suggesting a potential for reduced scarring. Furthermore, EAE and PEE could repair wounds by up-regulating TGF-ß1 in the early stage of wound repair and down-regulating TGF-ß1 in the late stage. In vitro studies showed that both EAE and PEE were able to promote NIH/3T3 cells proliferation and migration compared with the control group. CONCLUSIONS: In this study, EAE and PEE were found to significantly accelerate wound repair and might have an inhibitory effect on the generation of scars. It was also hypothesized that the mechanism might be related to the regulation of TGF-ß1 secretion. This study provided an experimental basis for the development of topical drugs for the treatment of burns with Dalbergia pinnata.


Assuntos
Queimaduras , Dalbergia , Camundongos , Ratos , Animais , Cicatriz/tratamento farmacológico , Cicatriz/patologia , Cicatrização , Fator de Crescimento Transformador beta1/farmacologia , Colágeno , Queimaduras/tratamento farmacológico
13.
Biotechnol Lett ; 33(5): 1007-11, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21246255

RESUMO

Saccharomyces cerevisiae was transformed for higher ethanol tolerance by error-prone whole genome amplification. The resulting PCR products were transformed back to the parental strain for homologous recombination to create a library of mutants with the perturbed genomic networks. A few rounds of transformation led to the isolation of mutants that grew in 9% (v/v) ethanol and 100 g glucose l(-1) compared to untransformed yeast which grew only at 6% (v/v) ethanol and 100 g glucose l(-1).


Assuntos
Antifúngicos/toxicidade , Farmacorresistência Fúngica , Etanol/toxicidade , Genoma Fúngico , Reação em Cadeia da Polimerase/métodos , Saccharomyces cerevisiae/efeitos dos fármacos , Transformação Genética , Etanol/metabolismo , Glucose/metabolismo , Viabilidade Microbiana , Mutação , Recombinação Genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo
14.
J Biotechnol ; 133(1): 96-102, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18029042

RESUMO

The expression of arabinogalactan-proteins (AGPs), known as extracellular signal molecules, in immobilized T. cuspidata cells was investigated by immunofluorescence localization and Western blot analysis. It was found that the relative intensity of JIM13-reactive AGPs and Taxol production by T. cuspidata cells was increased 1.43-fold and 2.2-fold by immobilized cultures on day 25, respectively. Particularly, the expression levels of JIM13-reactive AGPs were much higher in the cells located in central and middle zones of the immobilized support matrices than these in the outer zone or in the suspension. Whether in immobilized T. cuspidata cells or in suspended T. cuspidata cells, the expression level of JIM13-reactive AGPs and Taxol production after two to three subcultures had no significant changes, but the immobilized cells always kept high-level expression of JIM13-reactive AGP and Taxol production during subcultures. Moreover, the enhancement of Taxol production was accompanied with a high-level expression of JIM13-reactive AGPs by T. cuspidata cells after treatment with 200 microM methyl jasmonate. Taken together, these results implicate that the AGPs in T. cuspidata cells may be taken as potential signal molecular involved in regulating the Taxol production by immobilized T. cuspidata cells.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Mucoproteínas/metabolismo , Paclitaxel/metabolismo , Proteínas de Plantas/metabolismo , Taxus/metabolismo , Linhagem Celular , Células Imobilizadas
15.
Neuroscience ; 343: 434-448, 2017 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-27235741

RESUMO

Bexarotene has been proved to have neuroprotective effects in many animal models of neurological diseases. However, its neuroprotection in traumatic brain injury (TBI) is still unknown. This study aims to explore the neuroprotective effects of bexarotene on TBI and its possible mechanism. Controlled cortical impact (CCI) model was used to simulate TBI in C57BL/6 mice as well as APOE gene knockout (APOE-KO) mice. After CCI, mice were daily dosed with bexarotene or vehicle solution intraperitoneally. The motor function, learning and memory, inflammatory factors, microglia amount, apoptosis condition around injury site and main side-effects were all measured. The results showed that, after CCI, bexarotene treatment markedly improved the motor function and spatial memory in C57BL/6 compare to APOE-KO mice which showed no improvement. The inflammatory cytokines, microglia amount, cell apoptosis rate, and protein of cleaved caspase-3 around the injury site were markedly upregulated after TBI in both C57BL/6 and APOE-KO mice, and all these upregulation were significantly mitigated by bexarotene treatment in C57BL/6 mice, but not in APOE-KO mice. No side-effects were detected after consecutive administration. Taken together, bexarotene inhibits the inflammatory response as well as cell apoptosis and improves the neurological function of mice after TBI partially through apolipoprotein E. This may make it a promising candidate for the therapeutic treatment after TBI.


Assuntos
Apolipoproteínas E/metabolismo , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/imunologia , Fármacos Neuroprotetores/farmacologia , Tetra-Hidronaftalenos/farmacologia , Animais , Apolipoproteínas E/genética , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Bexaroteno , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/patologia , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/psicologia , Caspase 3/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/efeitos dos fármacos , Microglia/imunologia , Microglia/patologia , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Distribuição Aleatória , Memória Espacial/efeitos dos fármacos , Memória Espacial/fisiologia
16.
Appl Biochem Biotechnol ; 135(2): 145-58, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17159238

RESUMO

Constructing a mutant strain of single gene disruption is the basis for the study of gene function and metabolomics. Systematic and complete genome sequencing is the basis of genetic manipulation. In the case of a little knowledge about the Streptomyces lydicus genome and the speculation that polyketide synthases (type I) might be responsible for the polyketide side chain biosynthesis of streptolydigin, a 588-bp fragment was amplified by polymerase chain reaction (PCR) according to the homology existing in the same functional genes among Streptomyces. A mutant strain of this gene was constructed by single crossover homologous recombination. The results of sequence analysis as well as the metabolite analysis of the mutant and the original strain by liquid chromatography/mass spectroscopy indicated that this fragment was part of type II thioesterase (TE) gene, which was required for streptolydigin biosynthesis like other type II TEs function in related antibiotics biosynthesis. Furthermore, targeted gene manipulation based on PCR was a powerful tool for studying gene function and metabolomics, especially when little was known about the genomic sequence of streptomyces.


Assuntos
Ácido Graxo Sintases/metabolismo , Streptomyces/enzimologia , Tioléster Hidrolases/metabolismo , Sequência de Aminoácidos , Aminoglicosídeos/biossíntese , Sequência de Bases , Clonagem Molecular , Ácido Graxo Sintases/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Streptomyces/genética , Tioléster Hidrolases/genética
17.
Artigo em Inglês | MEDLINE | ID: mdl-27045834

RESUMO

Recently, many biological studies reported that two groups of genes tend to show negatively correlated or opposite expression tendency in many biological processes or pathways. The negative correlation between genes may imply an important biological mechanism. In this study, we proposed a FCA-based negative correlation algorithm (NCFCA) that can effectively identify opposite expression tendency between two gene groups in gene expression data. After applying it to expression data of cell cycle-regulated genes in yeast, we found that six minichromosome maintenance family genes showed the opposite changing tendency with eight core histone family genes. Furthermore, we confirmed that the negative correlation expression pattern between these two families may be conserved in the cell cycle. Finally, we discussed the reasons underlying the negative correlation of six minichromosome maintenance (MCM) family genes with eight core histone family genes. Our results revealed that negative correlation is an important and potential mechanism that maintains the balance of biological systems by repressing some genes while inducing others. It can thus provide new understanding of gene expression and regulation, the causes of diseases, etc.


Assuntos
Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Modelos Biológicos , Algoritmos , Ciclo Celular/genética , Bases de Dados Genéticas , Proteínas de Manutenção de Minicromossomo/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
18.
Appl Biochem Biotechnol ; 127(3): 173-85, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16377848

RESUMO

Dynamic changes in reactive oxygen species (ROS) of Taxus cuspidata cells immobilized on polyurethane foam were investigated and the relation between ROS content and taxol production was discussed. Immobilization shortened the lag period of cell growth and moderately increased H2O2 and O2-* contents inside the microenvironment within the first 15 d. After 20 d, excessive production of H2O2 and O2-* was observed accompanied by marked increases in membrane lipid peroxidation and cell membrane permeability. The taxol content of immobilized cells was fourfold that of suspended cells at d 35. The addition of exogenous H2O2 barely affected malondialdehyde content and cell membrane permeability but led to an obvious accumulation of taxol. It is inferred that the intracellular and extracellular H2O2 inside the microenvironment might be one factor promoting taxol biosynthesis under the immobilization stress.


Assuntos
Paclitaxel/biossíntese , Poliuretanos , Espécies Reativas de Oxigênio/metabolismo , Taxus/metabolismo , Técnicas de Cultura de Células , Células Imobilizadas/metabolismo , Taxus/citologia
19.
Mol Biotechnol ; 20(2): 137-43, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11876470

RESUMO

Addition of taxol into suspension cultures of Taxus cuspidata induced cell apoptosis, which was confirmed by gel electrophoresis of the DNA ladders indicating the progressive delineation of fragmented nuclear DNA (nDNA) into distinct bodies. The additional taxol not only changed the microtubule assembly of cells, but also affected the gene expression. Fourteen cDNA fragments, named as TIGT9-22, were isolated after addition of taxol and their GenBank accession numbers were given as BF704560-BF704573, respectively. Among them, TIGT13 and TIGT21 were apparently homogeneous with apbE and carbamoylphosphate synthetase, respectively. Other cDNA fragments showed no significant analogy with the known sequences in GenBank.


Assuntos
Fragmentação do DNA/fisiologia , DNA Complementar/isolamento & purificação , Paclitaxel/metabolismo , Taxus/genética , Taxus/metabolismo , Sequência de Aminoácidos , Apoptose/genética , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/metabolismo , Clonagem Molecular , Dano ao DNA/genética , DNA Complementar/classificação , DNA Complementar/genética , Bases de Dados de Ácidos Nucleicos , Eletroforese em Gel de Ágar , Eletroforese em Gel Bidimensional , Expressão Gênica , Genes/genética , Dados de Sequência Molecular , Paclitaxel/farmacologia , Reação em Cadeia da Polimerase , RNA/isolamento & purificação , Taxus/efeitos dos fármacos
20.
Appl Biochem Biotechnol ; 110(2): 61-74, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14515022

RESUMO

The biological responses of Taxus chinensis var. mairei suspension cultures to a range of shear rates were investigated in a Couette-type shear reactor. It was found that the shear rate below 458 s-1 enhanced the primary metabolism, increasing mitochondrial activity and protein expression and inhibiting the activity of phenylalanine ammonia lyase (PAL), an enzyme relevant to the secondary metabolism. However, the shear rate over 719 s-1 damaged taxus cells to some extent, decreasing the mitochondrial activity, increasing the membrane permeability, and even causing cell hypersensitive responses. As a result, PAL and intracellular peroxidase, an enzyme in cells relevant to reactive oxygen species scavenging, were activated and extracellular phenolics were accumulated. Additionally, shear-induced accumulation of free radicals and alkalization of the culture medium were observed. The results might shed light on a better understanding of the mechanism of plant cells responses to shear stress through the signal transduction pathway.


Assuntos
Reatores Biológicos , Estresse Mecânico , Taxus/metabolismo , Linhagem Celular , Taxus/citologia , Taxus/enzimologia
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