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1.
Nano Lett ; 24(1): 187-194, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38088862

RESUMO

Realistically, green manufacturing of transparent superhydrophobic surfaces (SHSs) and high liquid impalement resistance for outdoor engineering are very necessary but pretty challenging. To address this, an almost all-waterborne system composed of synthesized partially open-cage fluorinated polyhedral oligomeric silsesquioxane bearing a pair of -OH (poc-FPOSS-2OH), silica sol, and resin precursor is engineered. The transparent SHSs facilely formed by this system are featured with the exclusive presence of wrapped silica nanoparticle (SiNP) dendritic networks at solid-gas interfaces. The wrapped SiNP dendritic networks have a small aggregation size and low distribution depth, making SHSs highly transparent. The Si-O polymeric wrappers render mechanical flexibility to SiNP dendritic networks and thus enable transparent SHSs to resist high-speed water jet impinging with a Weber number of ≥19 800 in conjunction with the extremely low-surface-energy poc-FPOSS-2OH, which is the highest liquid impalement resistance so far among waterborne SHSs, and can rival the state-of-the-art solventborne SHSs.

2.
Hepatobiliary Pancreat Dis Int ; 18(6): 557-561, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31474445

RESUMO

BACKGROUND: Laparoscopic common bile duct exploration (LCBDE) is one of the minimally invasive options for choledocholithiasis. Primary closure of the common bile duct (CBD) upon completion of laparoscopic choledochotomy is safe in selected patients. The present study aimed to evaluate the feasibility and safety of primary closure of CBD after LCBDE in patients aged 70 years or older. METHODS: A total of 116 patients (51 males and 65 females) who suffered from choledocholithiasis and underwent primary closure of the CBD (without T-tube drainage) after LCBDE from January 2003 to December 2017 were recruited. They were classified into two groups according to age: group A (≥70 years, n = 56), and group B (<70 years, n = 60). The preoperative characteristics, intraoperative details, and postoperative outcomes of the two groups were evaluated. RESULTS: The mean operative time was 172.02 min for group A and 169.92 min for group B (P = 0.853). The mean hospital stay was 7.40 days for group A and 5.38 days for group B (P < 0.001). Bile leakage occurred in two patients in group A and one in group B (3.57% vs 1.67%, P = 0.952). There were no significant differences in the rates of postoperative complications and mortality between the two groups. At median follow-up time of 60 months, stone recurrence was detected in one patient in group A and two in group B (1.79% vs 3.33%, P = 1.000). Stenosis of CBD was not observed in group A and slight stenosis in one patient in group B (0 vs 1.67%, P = 1.000). CONCLUSION: Primary closure of the CBD upon completion of laparoscopic choledochotomy is safe and feasible in elderly patients ≥70 years old.


Assuntos
Colecistectomia Laparoscópica , Coledocolitíase/cirurgia , Ducto Colédoco/cirurgia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Colecistectomia Laparoscópica/efeitos adversos , Colecistectomia Laparoscópica/mortalidade , Coledocolitíase/diagnóstico por imagem , Coledocolitíase/mortalidade , Ducto Colédoco/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Recidiva , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
3.
Molecules ; 24(5)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813539

RESUMO

Here, we introduced a novel thiourea-based rhodamine compound as a chromo-fluorogenic indicator of nerve agent Soman and its simulant diethyl chlorophosphate (DCP). The synthesized probe N-(rhodamine B)-lactam-2-(4-cyanophenyl) thiourea (RB-CT), which has a rhodamine core linked by a cyanophenyl thiosemicarbazide group, enabled a rapidly and highly sensitive response to DCP with clear fluorescence and color changes. The detection limit was as low as 2 × 10-6 M. The sensing mechanism showed that opening of the spirolactam ring following the phosphorylation of thiosemicarbazides group formed a seven-membered heterocycle adduct, according to MS analysis and TD-DFT calculations. RB-CT exhibited high detecting selectivity for DCP, among other organophosphorus compounds. Moreover, two test kits were employed and successfully used to detect real nerve agent Soman in liquid and gas phase.


Assuntos
Corantes Fluorescentes/síntese química , Compostos Organofosforados/análise , Rodaminas/química , Soman/análise , Tioureia/química , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/química , Corantes Fluorescentes/química , Limite de Detecção , Estrutura Molecular , Agentes Neurotóxicos/análise , Agentes Neurotóxicos/química , Compostos Organofosforados/química , Soman/química
4.
Protein Expr Purif ; 141: 63-70, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28807839

RESUMO

Sulfur mustard (SM) can be hydrolyzed by haloalkane dehalogenases such as DhaA, LinB and DmbA. However, the low resistance to the elevated temperatures limited the practical application of haloalkane dehalogenases. Here we reported a new thermotolerant dehalogenase FM2382 from Fulvimarina manganoxydans sp. nov. 8047. The specific activity of FM2382 to SM is 0.6 U/mg. FM2382 possessed high heat stability (45 °C) in slight alkali environment (pH 7.5) and retained approximately 50% activity after incubation at 70 °C for 40 min. The catalytic activity of FM2382 was activated by Co2+ and Mg2+, and inhibited by Zn2+, Cu2+ and Fe3+. Furthermore, site-specific mutagenesis proved that D34, K207 D232, D237 were amino acid residues related to the catalytic activity of SM. In conclusion, we found a thermostable haloacid dehalogenases (HAD) family dehalogenase showing SM-degradation activity, which may be useful for practical application in the future.


Assuntos
Alphaproteobacteria/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Hidrolases/química , Hidrolases/metabolismo , Alphaproteobacteria/genética , Alphaproteobacteria/metabolismo , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Hidrolases/classificação , Hidrolases/genética , Modelos Moleculares , Gás de Mostarda/metabolismo , Filogenia
5.
Hepatol Res ; 47(7): 650-657, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27487979

RESUMO

AIM: Laparoscopic hepatectomy (LH), microwave ablation (MWA), and open hepatectomy (OH) are three widely used methods to treat small hepatocellular carcinoma (HCC). However, few studies have compared the short- and long-term outcomes of these three treatments. The aim of this study was to investigate their effectiveness. METHODS: The data were reviewed from 280 patients with HCCs measuring ≤3 cm (Barcelona Clinic Liver Cancer stage 0 or A) who received LH (n = 133), OH (n = 87), or MWA (n = 60) in our research center from 2005 to 2010. Short-term outcomes included intraoperative blood loss, operation time, and length of hospital stay. The disease-free survival and overall survival rates were analyzed as long-term outcomes. RESULTS: The patients in the MWA and LH groups showed better short-term outcomes compared with those in the OH group. There were no significant differences in overall survival rates among the three treatments. The LH group showed significantly lower recurrence rates than the MWA group (P = 0.0146). CONCLUSIONS: Laparoscopic hepatectomy may be a better option for patients with small HCC located on the liver surface and left lateral lobe. The short-term outcome of MWA is promising, although the high risk of local recurrence after the operation should be considered when planning treatment.

6.
Wei Sheng Yan Jiu ; 42(1): 107-9, 113, 2013 Jan.
Artigo em Zh | MEDLINE | ID: mdl-23596719

RESUMO

OBJECTIVE: To investigate the effect of angelica keiskei chalcone (AC) on the expression of glucose transporter2 (Glut2) in liver and glucose transporter 4 (Glut4) in skeletal muscle cells of rats with type2 diabetes. METHODS: Made type2 diabetic rat models and divided into high, middle, low dose groups and diabetic control group randomly which were given chalcone 30, 10, 5 and 0 mg/kg BW respectively. Four groups were fed with the diet containing high fat. After four weeks, fasting blood glucose was determined by glucose oxidase method. Insulin was assessed by radio-immunity method. The expression levels of Glut2 in liver and Glut4 in skeletal muscle cells were analyzed by immunohistochemistry method. RESULTS: After analyzed by Image-Pro Plus on immunohistochemistry pictures, the expression levels of Glut2 in liver and Glut4 in skeletal muscle cells in high group were (0.036 +/- 0.0030) and (0.063 +/- 0.0139), which were significantly higher than the model control group (P < 0.05). The levels of fasting blood glucose and insulin in high dose group were (12.3 +/- 1.64) mmol/L and (25.65 +/- 3.34) microIU/ml, significantly lower than those of the model control group (P < 0.05). CONCLUSION: Angelica keiskei chalcone may increase the expression levels of Glut2 in liver and Glut4 in skeletal muscle cells, decrease fasting blood glucose and insulin of type 2 diabetic rats and improve their insulin resistance condition.


Assuntos
Angelica/química , Chalcona/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Transportador de Glucose Tipo 2/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Fígado/metabolismo , Animais , Chalcona/isolamento & purificação , Diabetes Mellitus Experimental/metabolismo , Resistência à Insulina , Fígado/citologia , Masculino , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar
7.
Wei Sheng Yan Jiu ; 42(3): 466-9, 2013 May.
Artigo em Zh | MEDLINE | ID: mdl-23805528

RESUMO

OBJECTIVE: To study the effect of chalcones extracted from Angelica Keiskei (AC) on the mRNA expression of phosphatidy I inositol 3-kinase (PI3K) and serine-threonine kinases (Akt) in hepatocytes of rats with diabetes. METHODS: The diabetes of rats was induced by streptozotocin with intraperitoeal injection as well as with high-fat diet feeding. The rats were randomly divided into 3 groups with 10 rats in each group,diabetic control group, high-dose AC group and low-dose AC group. All the rats were fed with high-fat diet. 0, 30 and 10 mg/kg BW AC per day were given to high-dose AC, low-dose AC and the diabetic control groups,respectively. Another 10 normal rats fed with regular diet were used as the normal control group. After 4 weeks, serum insulin levels were evaluated by radioimmunoassay. The mRNA expression levels of PI3K and Akt were determined by reverse transcription polymerase chain reaction (RT-PCR). The phosphorylation levels of Akt in hepatocytes were detected by western blot. Blood glucose levels were measured by glucose oxidase method. RESULTS: Compared with rats in the diabetic control gruop, the levels of blood glucose and serum insulin in rats of high-dose AC gruop were decreased and the PI3K and AKT mRNA expression levels were increased. All the difference was statistically significant (P<0.05). CONCLUSION: AC may upregulate the mRNA expression levels of PI3K and Akt and improve insulin resistance of rats with diabetes.


Assuntos
Angelica/química , Chalconas/farmacologia , Diabetes Mellitus Experimental/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Hepatócitos/metabolismo , Resistência à Insulina , Masculino , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Regulação para Cima
8.
J Vis Exp ; (193)2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-37010287

RESUMO

Laparoscopic hepatectomy is an important treatment method for liver cancer. In the past, the resection boundary was usually determined by intraoperative ultrasound, important vascular structures, and surgeon experience. With the development of anatomical hepatectomy, visual surgery technology has gradually been applied to this type of surgery, particularly indocyanine green (ICG)-guided anatomical hepatectomy. As ICG can be specifically ingested by hepatocytes and used for fluorescence tracing, negative staining techniques have been applied according to different tumor positions. Under ICG fluorescent guidance, the surface boundary and deep resection plane can be more accurately displayed during liver resection. Thus, the tumor-bearing liver segment can be anatomically removed, which helps to avoid damage to important vessels and reduce ischemia or congestion of the remaining liver tissue. Finally, the incidence of postoperative biliary fistula and liver dysfunction is reduced; therefore, a better prognosis is obtained after the resection of liver cancer. Centrally located liver cancer is usually defined as a tumor located at segments 4, 5, or 8 that requires resection of the middle section of the liver. These are among the most difficult hepatectomies to perform because of the large surgical wounds and multiple vessel transections. Based on the specific tumor location, we formulated the required resection ranges by designing personalized fluorescent staining strategies. By completing anatomical resection based on the portal territory, this work aims to achieve the best therapeutic effect.


Assuntos
Carcinoma Hepatocelular , Laparoscopia , Neoplasias Hepáticas , Humanos , Verde de Indocianina , Hepatectomia/métodos , Coloração Negativa , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Corantes , Laparoscopia/métodos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia
9.
Wei Sheng Yan Jiu ; 41(2): 264-7, 2012 Mar.
Artigo em Zh | MEDLINE | ID: mdl-22611938

RESUMO

OBJECTIVE: To investigate the effects of magnesium intake on expression of insulin receptor in type 2 diabetes rats. METHODS: The models of type 2 diabetes rats were established by feeding with high-fat-diet and injecting streptozotocin (STZ). Rats were randomly assigned to four groups. The high-fat-diets were administrated magnesium at a dose of 2000 (high magnesium group), 1000 (medium magnesium group) and 200 (low magnesium group). Model control group was only fed with high-fat-diet. Normal control group was fed with common diet. Rats ate freely for four weeks. Fasting blood glucose was detected by glucose oxidase method.. Insulin was detected by radio-immunity method. The expression levels of IR of pancreas and skeletal muscle were detected by immunohistochemistry method. RESULTS: The immunohistochemistry pictures were analyzed by Image-Pro Plus. Compared with model control group, the expression levels of IR of pancreas and skeletal muscle were 0.341 +/- 0.001 and 0.346 +/- 0.002, increased and fasting blood glucose decreased significantly in high magnesium group (P < 0.05 ). CONCLUSION: Magnesium intake may increase the expression levels of IR of pancreas and skeletal muscle, and decrease fasting blood glucose in type 2 diabetes rats.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Magnésio/administração & dosagem , Receptor de Insulina/metabolismo , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Músculo Esquelético/metabolismo , Pâncreas/metabolismo , Ratos , Ratos Wistar
10.
ACS Appl Mater Interfaces ; 14(47): 53421-53432, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36384285

RESUMO

Developing high-performance protective materials is important for soldiers and civilians who are exposed to the atmosphere of highly toxic chemical warfare agents (CWAs). Polyelectrolyte membranes are promising candidates with excellent chemical resistance and moisture permeability, but they cannot efficiently degrade CWAs. Here, we design and prepare a hybrid membrane through in situ growth of catalytically active zirconium-based metal-organic frameworks (Zr-MOFs) on a polyelectrolyte membrane mediated by biofilm-inspired curli nanofibers (CNFs). Superior to the bare polyelectrolyte membrane, the prepared MOF-808@CNF-PQ hybrid membrane exhibits improved rejection of the nerve agent simulant dimethyl methyl phosphonate (DMMP) vapor and permeation of the water vapor by 113 and 45%, respectively. The water/DMMP selectivity of the hybrid membrane reaches 498.6, approximately 13 times that of the commercial polyelectrolyte membrane Nafion 117. In addition, the hybrid membrane possesses appreciable catalytic activity for the hydrolysis of the nerve agent simulant dimethyl 4-nitrophenyl phosphate (DMNP) with a half-life of ∼38 min. Nanomechanical characterization results based on atomic force microscopy (AFM) techniques demonstrate the critical role of CNFs in mediating Zr-MOF nucleation and the dominant effect of electrostatic interactions on self-assembly of CNFs on polyelectrolyte base. It is also confirmed that the Zr-MOF toppings serve as the key components in physically adsorbing and chemically degrading the DMNP molecules through multiple strong intermolecular interactions. Our work offers a rational strategy to develop advanced membranes toward efficient chemical protection, moisture permeation, and catalytic detoxification against CWAs.

11.
Nat Prod Res ; 36(5): 1396-1399, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33691545

RESUMO

Two sterols and seven triterpenoids were isolated and identified from Ganoderma lucidum by silica gel column chromatography, preparative high-performance liquid chromatography and spectra analysis. Then, the multidrug resistance reversal activities of these compounds were assessed using MTT assay. Among these compounds, ganoderol B (3), ganoderone A (4), ganodermanondiol (6) and ganoderiol F (8) were shown to reverse the resistance of human oral epidermoid carcinoma cell line KBv200 to doxorubicin, and the reversal folds were 6.59, 4.70, 4.01 and 7.09, respectively. Ganoderiol F could increase the intracellular accumulation of doxorubicin in KBv200 cells through inhibiting P-glycoprotein transport function. Further mechanistic investigation found that ganoderiol F did not alter P-glycoprotein expression. In conclusion, ganoderiol F has potent effect in reversing P-glycoprotein mediated tumor multidrug resistance. Potential reversal agents against multidrug resistance in tumor may be found in triterpenoids from Ganoderma lucidum.[Formula: see text].


Assuntos
Reishi , Triterpenos , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Reishi/química , Esteróis/farmacologia , Triterpenos/química , Triterpenos/farmacologia
12.
Wei Sheng Yan Jiu ; 40(2): 220-2, 2011 Mar.
Artigo em Zh | MEDLINE | ID: mdl-21560315

RESUMO

OBJECTIVE: To investigate the effect of seaweed pigment glycoprotein (SPG) on the expression of PCNA and Bcl-2 protein in hepatocarcinoma cells in mice. METHODS: Fifty mice inoculated with hepatocarcinoma cells were divided into five groups, 10 mice in each group. SPG was given by gavage at the dosage of 100, 50 and 10 mg/kg everyday to high, medium and low dose group respectively, normal saline was given orally to tumor control group, and cyclophosphamide 20 mg/kg was injected to the cylophosphamide group every the other day, all mice were sacrificed 10 days later. The proliferation activity of hepatocarcinoma cells was determined by MTT assay, and the expression of proliferating cell nuclear antigen (PCNA) and Bcl-2 protein were measured by immunohistochemical method. RESULTS: The cell proliferation activity expressed by the optical density of the high-dose group and tumor control group were 0.711 +/- 0.028 and 1.135 +/- 0.032 respectively (P < 0.05). The expression of PCNA and Bcl-2 protein in high-dose group was 28.32% and 16.78% respectively, and that in tumor control group was 72.78% and 65.16% respectively (P < 0.05). CONCLUSION: The proliferation activity of hepatocarcinoma cells in mice could be reduced and the expression of PCNA and Bcl-2 protein could be inhibited by SPG.


Assuntos
Glicoproteínas/farmacologia , Neoplasias Hepáticas Experimentais/metabolismo , Pigmentos Biológicos/farmacologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Alga Marinha/química , Animais , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Proliferação de Células/efeitos dos fármacos , Feminino , Glicoproteínas/isolamento & purificação , Neoplasias Hepáticas Experimentais/patologia , Masculino , Camundongos , Pigmentos Biológicos/isolamento & purificação , Proteínas Proto-Oncogênicas c-bcl-2
13.
Wei Sheng Yan Jiu ; 40(1): 30-1, 35, 2011 Jan.
Artigo em Zh | MEDLINE | ID: mdl-21434306

RESUMO

OBJECTIVE: To study the effect of grape procyanidins (GPC) on the expressions of Caspase-3 and Bax in the liver of mice with ethanol-induced liver injury. METHOD: The mice were orally given at the different doses of GPC (50,100 and 200 mg/kg) and 4 g/kg ethanol, and killed after 4 weeks. The proliferation activity of the hepatic cells was determined by MTT assay,the levels of Caspase-3 and Bax protein expression in the cells were measured by immunohistochemistry method. RESULTS: The expression level of Caspase-3 and Bax protein in high dose group were 19.08% and 14.06%, respectively, and those of the ethanol-injured group were 51.78% and 58.08%. The differences between the two groups were significant (P < 0.05). The cell proliferation activity of high dose and medium dose group was higher than the cell proliferation activity of ethanol-injured group (P < 0.05). CONCLUSION: GPC could suppressing the expression of Caspase-3 and Bax in the liver of mice with ethanol-induced liver injury.


Assuntos
Caspase 3/metabolismo , Extrato de Sementes de Uva/química , Hepatopatias Alcoólicas/metabolismo , Proantocianidinas/farmacologia , Proteína X Associada a bcl-2/metabolismo , Animais , Etanol/administração & dosagem , Feminino , Fígado/metabolismo , Hepatopatias Alcoólicas/tratamento farmacológico , Masculino , Camundongos , Proantocianidinas/isolamento & purificação , Proantocianidinas/uso terapêutico
14.
J Biomol Struct Dyn ; 39(16): 5999-6007, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32696722

RESUMO

With the increasing application of enzymes in various research fields, the choices of co-solvents in enzymatic preparations which directly related to the catalytic activity have been attracted attention. Thus, researching on the stabilization or destabilization behaviors of enzymes in different solvents is extremely essential. In this study, the structural changes of DhaA in two typical aprotic co-solvents (acetonitrile and tetrahydrofuran) were firstly investigated by molecular dynamics (MD) simulation. The simulation results revealed the strong van der Waals force between co-solvents and DhaA which could induce the structural change of enzyme. Interestingly, the differences of molecular size and the electrostatic force with enzyme of two co-solvents led to quite different influences on DhaA. As for acetonitrile, solvent molecules could penetrate into the catalytic site of DhaA which promoted by the electrostatic interaction. On the contrary, tetrahydrofuran molecules were mainly distributed around the catalytic site due to the relative weak electrostatic interaction and steric resistance effect. It can be concluded that different co-solvent can affect the key domains, substrate pathway and catalytic pocket of DhaA.Communicated by Ramaswamy H. Sarma.


Assuntos
Hidrolases , Simulação de Dinâmica Molecular , Catálise , Domínio Catalítico , Solventes
15.
J Biotechnol ; 335: 47-54, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34118331

RESUMO

Haloalkane dehalogenase DhaA can catalyze the hydrolytic cleavage of carbonhalogen bonds, along with production of the corresponding alcohol, a proton and a halide. However, DhaA suffers from poor environmental tolerance, such as sensitivity to high temperature, low pH and hypersaline. Arabinogalactan (AG) is a hydrophilic polysaccharide with highly branched long chains. DhaA was conjugated with AG to improve the environmental stability of DhaA in the present study. Each DhaA was averagely conjugated with 4∼5 AG molecules. Conjugation of AG essentially maintained the enzymatic activity of DhaA (91.4 %) without apparent structural alteration. The hydration layer formed by AG could reduce the solvent accessible area of DhaA and slow the protonation process, thereby improving the pH and high salt stability of DhaA. In particular, the remaining activities of the conjugate (AG-DhaA) were 35.3 % after treatment at pH4.0 for 1 h, and 80.8 % in 1 M NaCl after treatment for 16 h. As compared with DhaA, AG-DhaA showed slightly different kinetic parameters (K M of 1.90 µmol/L and k cat of 2.60 s -1).


Assuntos
Rhodococcus , Galactanos , Hidrolases
16.
Enzyme Microb Technol ; 149: 109832, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34311877

RESUMO

Haloalkane dehalogenase DhaA catalyzes the hydrolytic cleavage of carbon-halogen bonds and produces alcohol, a proton and a halide. However, DhaA suffers from the poor environmental stability, such as sensitivity to high temperature, low pH, hypersaline and organic solvent. In order to improve the environmental stability of DhaA, DhaA was covalently conjugated with inulin, a hydrophilic polysaccharide in the present study. Each DhaA was averagely conjugated with 7∼8 inulin molecules. The conjugated inulin could form a hydration layer around DhaA, which increased the conformational rigidity and decreased the entropy of the enzyme. Conjugation of inulin maintained 75.5 % of the enzymatic activity of DhaA and slightly altered the structure of DhaA. As compared with DhaA, the conjugate (inu-DhaA) showed slightly different kinetic parameters (Km of 2.9 µmol/L and Kcat of 1.0 s-1). Inulin conjugation could delay the structural unfolding and/or slow the protonation process of DhaA under undesirable environment, including the long-term storage, low pH, hypersaline and organic solvent stability. As a result, the environmental stability of DhaA was markedly increased upon conjugation with inulin. Thus, inulin conjugation was an effective approach to enhance the environmental stability of DhaA.


Assuntos
Inulina , Rhodococcus , Hidrolases/genética , Hidrólise
18.
Enzyme Microb Technol ; 146: 109766, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33812563

RESUMO

Phosphotriesterase (PTE) is considered to be a good biodegradation agent for organophosphorus pesticides. However, the instability of the free PTE limits its application. In this study, the free PTE was hybridized with copper ions (Cu2+) to enhance its catalytic stability and activity. The acquired particles were freeze-dried after precipitation with PO43- at 4 °C for 72 h. Scanning electron microscopy showed that the Cu-PTE complexes formed flower-like nanoparticles after hybridization. The characteristic peaks of both the enzyme and metal material were revealed by Fourier transform-infrared spectroscopy. X-ray diffraction analysis indicated that PTE was encapsulated in the Cu3(PO4)2·3H2O based hybrid nanoflowers. Compared with free PTE, the catalytic activity of Cu-PTE hybrid nanoflowers was significantly increased about 2.2 fold. The catalytic efficiency (kcat/Vmax) of Cu-PTE hybrid nanoflowers was 1.76 fold than that of free PTE. The stability of the immobilized PTE under thermal and pH conditions was improved and the tolerance of it to organic solvents was also enhanced. Moreover, the Cu-PTE hybrid nanoflowers still exhibited 72.3 % relative activity after ten consecutive reactions. In general, this is the first time to use copper based hybrid nanoflowers to immobilize PTE, and the immobilized enzyme shows excellent performance on OPs degradation. The Cu-PTE hybrid nanoflowers may have great potential in the biodegradation of organophosphorus compounds in future.


Assuntos
Nanoestruturas , Praguicidas , Hidrolases de Triester Fosfórico , Cobre , Compostos Organofosforados
19.
Wei Sheng Yan Jiu ; 39(2): 228-31, 2010 Mar.
Artigo em Zh | MEDLINE | ID: mdl-20459044

RESUMO

OBJECTIVE: To investigate the effect of alpha-naphthlcetic acid on the proliferation and apoptosis of testis cell. METHODS: Twenty five mice were divided into five groups, 5 mice per group. Basal animal food was fed to the mice in the normal control and positive control groups. Five thousand, 1000, 200 mg/kg of alpha-naphthlcetic acid were added into another three groups. Three days before sacrifice, the mice in positive control group were intraperitoneally injected with cyclophosphamide of 20 mg/kg each day. Four weeks later, all the mice were sacrificed. The proliferation activity of the testis cells was determined by MTT assay, and the levels of Caspase-3 and PCNA protein expression in testis cell were measured by immunohistochemistry method. RESULTS: The testis cell proliferation activity of the high dose group and the normal control group were 0.501 +/- 0.069 and 0.875 +/- 0.082. The difference was significant (P < 0.05). The expression level of PCNA protein and Caspase-3 of the high dose group were 8.9% and 41.3%, respectively, and those of the normal control group were 34.9% and 9.1%. The differences between two groups were significant (P < 0.05). CONCLUSION: alpha-naphthlcetic acid can inhibit the proliferation and induce the apoptosis of testis cells effectively.


Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácidos Naftalenoacéticos/toxicidade , Testículo/citologia , Animais , Caspase 3/metabolismo , Masculino , Camundongos , Antígeno Nuclear de Célula em Proliferação/metabolismo , Distribuição Aleatória
20.
Artigo em Zh | MEDLINE | ID: mdl-21033155

RESUMO

OBJECTIVE: To study the effect of the submarine training on the antioxidant ability of the submarine men. METHODS: 50 sea-training submarine men, 50 land-training submarine men and 50 resting submarine men were randomly selected from some submarine troops. The blood routine, the total antioxidative capacity (T-AOC), the content of malondialdehyde (MDA) and the levels of IFN-gamma in blood plasma, the hemolytic degree of RBC, the proliferation of peripheral-blood lymphocyte (PPL) of them were detected in each group. RESULTS: The T-AOC of the sea-training submarine men, the land-training submarine men and the resting submarine men significantly increased by turns [(15.38 +/- 3.11), (18.81 +/- 2.45), (20.93 +/- 2.95) U/ml], but MDA and the hemolytic degree of RBC significantly decreased by turns [(2.56 +/- 0.70), (2.12 +/- 0.53),(1.77 +/- 0.56) nmol/ml and 25.72% +/- 1.67%, 21.45% +/- 1.02%, 18.28% +/- 1.37%] (P < 0.05). Compared with the land-training submarine men and the resting submarine men, IFN-gamma [(31.89 +/- 3.52) pg/ml] and the proliferation of PPL of the sea-training submarine men were significantly lower, whereas the red blood count (RBC) and hemoglobin (Hb) were significantly higher (P < 0.05). CONCLUSION: Submarine training, especially sea training, may decrease the antioxidant ability.


Assuntos
Antioxidantes/fisiologia , Militares , Medicina Submarina , Adolescente , Contagem de Eritrócitos , Humanos , Interferon gama/sangue , Masculino , Malondialdeído/sangue , Adulto Jovem
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