Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Adicionar filtros








Intervalo de ano
1.
Chinese Journal of Reparative and Reconstructive Surgery ; (12): 447-451, 2020.
Artigo em Chinês | WPRIM | ID: wpr-856353

RESUMO

Objective: To compare the effectiveness of Taylor spatial frame (TSF) and unilateral external fixator in the treatment of tibiofibular open fractures. Methods: Between January 2016 and July 2018, 74 patients with tibiofibular open fracture who met the selection criteria were divided into TSF group (43 cases, fixed with TSF) and unilateral group (31 cases, fixed with unilateral external fixator) according to the principle of entering the group every other day. There was no significant difference in gender, age, affected side, cause of injury, type of fracture between the two groups ( P>0.05). The operation time, fracture healing time, removal time of external fixator, and complications were recorded and compared between the two groups. The limb function was evaluated according to Johner-Wruhs criteria for evaluating the final effectiveness of tibial shaft fracture treatment. The recovery of lower limb force line was ecaluated by LUO Congfeng et al. criteria. Results: All patients were followed up 8-22 months, with a median of 12 months. All fractures healed, and no complication such as delayed union, nonunion, or osteomyelitis occurred. The operation time, fracture healing time, and removal time of external fixator in TSF group were significantly shorter than those in unilateral group ( P<0.05). At 3 months after the removal of the external fixator, the limb function was evaluated according to the Johner-Wruhs standard. In TSF group, 41 cases were excellent, 1 case was good, and 1 case was fair, and the excellent and good rate was 97.67%; in unilateral group, 30 cases were excellent and 1 case was fair, and the excellent and good rate was 96.77%; there was no significant difference between the two groups ( P=0.666). At 4 months after operation, the recovery of lower limb force line was ecaluated by LUO Congfeng et al. criterion. In TSF group, 41 cases were excellent, 2 cases were good, and 1 case was fair, and the excellent and good rate was 97.67%; in unilateral group, 29 cases were excellent, 1 case was good, 1 case was fair, and the excellent and good rate was 96.77%; there was no significant difference between the two groups ( P=0.666). Conclusion: For tibiofibular open fracture, on the premise of fracture healing, TSF technology is superior to unilateral external fixation in terms of shortening operation time, fracture healing time, and removal time of external fixator.

2.
Chinese Journal of Neurology ; (12): 406-409, 2019.
Artigo em Chinês | WPRIM | ID: wpr-745946

RESUMO

Paraneoplastic neurological syndromes (PNS) are a rare group of immune-mediated disorders that affect the central and peripheral neuromuscular system in association with cancer.If the limbal lobe system of the brain is involved,it will show paraneoplastic limbal encephalitis(PLE).The discern of patients with PNS is challenging since tumors causing paraneoplastic neurologic disorders are often asymptomatic and sometimes occult.We report a case of PLE with double positive anti-Hu and Yo antibodies,and further analyze and discuss it in conmbination with relevant literature to improve the understanding of the disease.

3.
Journal of Regional Anatomy and Operative Surgery ; (6): 67-70, 2019.
Artigo em Chinês | WPRIM | ID: wpr-744552

RESUMO

Objective To explore the best indication of neuroendoscopic surgery in patients with pituitary tumors by comparing the clinical effects of neuroendoscopic transsphenoidal surgery on patients with different types of pituitary tumors.MethodsA total of 92 patients with different types of pituitary adenoma received transsphenoidal approach under neuroendoscopy in our hospital from June 2016 to October2017 were selected, the surgical results were evaluated by comparing the postoperative hormone levels were normal or not and the tumor were resected or not.The patients were followed up, the physiological function (PF), physiological function (RP), emotional functions (RE) was determined by health measurement scale (SF-36) to evaluated the quality of life of patients.Results There were differences in clinical efficacy of neuroendoscopy for the treatment of different types of pituitary adenoma, the cure rate from high to low in turn was cortical hormone adenomas, growth hormone adenomas, prolactin adenomas, mixed adenoma, non-functional adenomas, the cure rate of functional pituitary adenoma was obviously higher than that of no functional pituitary adenoma, the difference was statistically significant (P<0.05).At 6 months after surgery, SF-36 result showed that PF scores was (76.30±8.68), RP scores was (78.37±19.05), RE scores was (71.54±21.54), and at 12 months after surgery, PF scores was (87.20±9.24), RP scores was (78.66±15.18) and RE scores was (87.80±17.67), which were higher in patients with functional pituitary adenoma than those in patients with non-functional pituitary adenoma, the differences were significant (P<0.05).ConclusionThe treatment of functional pituitary tumor by neuroendoscopic surgery, especially corticosteroid adenoma, has the best effect, and can significantly improve the quality of life of patients.

4.
Chinese journal of integrative medicine ; (12): 108-115, 2019.
Artigo em Inglês | WPRIM | ID: wpr-776602

RESUMO

OBJECTIVE@#To determine the effects of hawthorn extract on serum lipid levels, pathological changes in aortic atherosclerosis plaque, inflammatory factors, and apoptosis-related protein and mRNA expression in apolipoprotein E gene knockout (ApoE) mice.@*METHODS@#Thirty-six ApoE mice were fed with a high-fat diet starting at the age of 8 weeks. Mice were randomly divided into 3 groups by a random number table including model group, hawthorn extract group, and simvastatin group, 12 mice in each group. Twelve 8-week-old C57BL/6 mice were fed a basic diet and served as control. The mice in the control and model groups were administered 0.2 mL saline daily, the mice in the hawthorn extract and simvastatin groups were administered with 50 mg/kg hawthorn extract or 5 mg/kg simvastatin daily for 16 weeks. After 16 weeks, plasma lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined by an enzymatic assay. Aortic atherosclerotic lesions were observed by light microscopy, scanning and transmission electron microscopy, respectively. Plasma levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-1β (IL-1β), adiponectin (APN), and hypersensitive C-reactive protein (hs-CRP) were measured by enzyme-linked immunosorbent assay (ELISA). Protein and mRNA expressions of Bax and Bcl-2 in the aorta were assessed by Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR), respectively.@*RESULTS@#Compared to the control group, the plasma levels of TC, TG and LDL-C were significantly increased and HDL-C were significantly decreased in the model group (P<0.01). Compared to the model group, treatment with hawthorn extract significantly decreased the plasma levels of TC, TG, and LDL-C and increased the plasma level of HDL-C in ApoE mice (P<0.01). The levels of MCP-1, IL-1ß, and hs-CRP in the model group were significantly increased and APN was significantly decreased compared with the control group (P<0.01). Compared to the model group, treatment with hawthorn extract decreased the levels of MCP-1, IL-1ß, and hs-CRP and increased the APN level (P<0.01). Compared to the control group, the protein and mRNA expression of Bax in the model group were significantly increased and the expression of Bcl-2 was significantly decreased (P<0.01). Hawthorn extract also reduced the protein and mRNA expression of Bax and increased the Bcl-2 expression in the aorta (P<0.01).@*CONCLUSION@#Hawthorn extract has anti-atherosclerosis and stabilizing unstable plaque effects. The mechanism may be related to the inflflammation and apoptosis signaling pathways.


Assuntos
Animais , Masculino , Aorta , Patologia , Apoptose , Aterosclerose , Sangue , Tratamento Farmacológico , Crataegus , Química , Inflamação , Sangue , Tratamento Farmacológico , Mediadores da Inflamação , Metabolismo , Lipídeos , Sangue , Camundongos Endogâmicos C57BL , Extratos Vegetais , Farmacologia , Usos Terapêuticos , RNA Mensageiro , Genética , Metabolismo , Proteína X Associada a bcl-2 , Metabolismo
5.
Chinese Journal of Hospital Administration ; (12): 1026-1030, 2018.
Artigo em Chinês | WPRIM | ID: wpr-735118

RESUMO

Objective To systematic review the influence of case-based payment on inpatient costs since China′s new medical reform. Methods Studies about inpatient costs before and after the implementation of case-based payment were collected. The literature collected underwent a meta-analysis by RevMan 5. 0. Results A total of 11 articles in compliance were included in the study. The meta-analysis of random effect model showed the overall effect size (SMD) was -1. 54 with 95% CI being -1. 79, -1. 29, showing a significant difference (P<0. 05). The subgroup analysis showed that the overall effect size (MD) in the low-cost disease group was -585. 57 yuan with 95% CI being -750. 34, -420. 80, showing a significant difference (P < 0. 05). The overall effect size (MD) in the high-cost disease group was-4 172.65 yuan with 95% CI being -5 368. 21, -2 977. 10, showing a significant difference ( P <0.05). The funnel plot was approximately symmetrical, suggesting a publication bias as less likely in the study. Conclusions The implementation of case-based payment has reduced the inpatient costs to some extent thanks to China′s new healthcare reform. And the effect in the high-cost disease group was more obvious than that in the low-cost disease group.

6.
Chinese Journal of Cerebrovascular Diseases ; (12): 119-123, 2018.
Artigo em Chinês | WPRIM | ID: wpr-702996

RESUMO

Objective To compare the safety and efficacy of stent-assisted coil and non-stent-assisted coil for the treatment of ruptured posterior communicating artery aneurysms.Methods A total of 121 consecutive patients with ruptured posterior communicating artery aneurysm treated at the Department of Neurosurgery,Heze Municipal Hospital between June 2014 and June 2017 were enrolled retrospectively.They divided into either a stent group (n =63) or non-stent group (n =58) according to whether they used stent treatment or not.The two groups were compared,and their clinical data,surgical related complications,the degree of embolism immediately after aneurysm surgery,and the follow-up results of clinical and imaging were analyzed.Results Interventional embolization therapy was successfully performed in all the patients.(1) The proportion of wide-necked aneurysms of the stent group was higher than that of the non-stent group.There was significant difference (92.1% [58/63] vs.8.6% [5/58],x2 =84.249,P < 0.01).There were no significant differences in age,aneurysm size,sex,and HuntHess grade (all P > 0.05).(2) The incidences of intraoperative aneurysm rupture of the stent group and non-stent group were 4.8% (3/63) and 3.4% (2/58) respectively.There was no significant difference (x2 =0.132,P =0.717).The incidence of thromboembolie complication was 12.7% (8/63) and 5.2% (3/58)respectively.There was no significant difference (x2 =2.070,P =0.150).In the stent group,1 patient disabled and 1 died,and in the non-stent group,there were no cases with surgical related disability,and 1 died.(3) The comparison of immediate results after procedure between the stent group and non-stent group:there were no significant differences in the complete embolic rate (39.7% [25/63] vs.37.9%[22/58],x2 =0.039),aneurysm neck residual rate (25.4% [16/63] vs.39.7% [23/58],x2 =2.811],and residual rate of aneurysm (34.9% [22/63] vs.22.4% [13/58],x2 =2.298,all P > 0.05).(4) The recurrence rate of aneurysms (4.3% [2/46]) of the stent group was lower than that of the non-stent group (31.8% [14/44]).There was significant difference between the two groups (x2 =112.610,P =0.01).No rebleeding occurred in all aneurysms after procedure.Conclusion Compared with the non-stent-assisted coil embolization,the stent assisted embolization of ruptured posterior communicating artery aneurysms in acute phase may reduce the recurrence rate of aneurysms and without significantly increasing the incidence of surgery-related complications.

7.
Chinese Journal of Hospital Administration ; (12): 547-551, 2018.
Artigo em Chinês | WPRIM | ID: wpr-712565

RESUMO

Objective To evaluate the current deployment of general practitioners and residents′utilization of services in China, for reference of their optimal allocation across the country. Methods The methods of HRDI and TOPSIS were used to comprehensively evaluate their deployment and residents′utilization of their services in China. Results General practitioners fall short of demand in general, averaging 0.137 1 GP per 1 000 population in China, with unbalanced regional distribution as well. Utilization of residents of general practitioners service remains at a low level, with unbalanced regional distribution as well. As shown in the comprehensive evaluation results, 87.10% of the regions were found with defective deployment and service utilization, featuring " low resources, low utilization" . Conclusions Sizable gapes are found between the eastern, the central and the western regions, in terms of allocation of resources and service utilization. The government should rationalize deployment of general practitioners and minimize such gaps among different regions, in view of local population, geography and health service needs.

8.
Chinese Journal of Hospital Administration ; (12): 231-236, 2018.
Artigo em Chinês | WPRIM | ID: wpr-712494

RESUMO

Objective To analyze the current situation of the official micro-blogs of the health and family planning commissions of provincial level, and to understand its application approaches.Methods The internet crawler software was used to collect the 102 899 micro-blog posts published by 24 official micro-blogs of health and family planning commissions of provincial level,and analyze the information of crawling by using content analysis method.Results At present, except for a number of provinces in the eastern regions where such micro-blogs were active and interactive,most of these official micro-blogs were found poor in operation management, especially in the spreading capacity; their micro-blog content was focused on science popularization(59.50%).Part of the content lacked scientific basis,and was short of planning in their information release form and content.Conclusions These micro-blogs need optimization in operations management,service positioning,information release specifications,and content audit.Such efforts can help improve their spreading capacity,influence and user viscosity, in order to better serve the public, achieve the goal of a service-oriented government.

9.
Chinese Journal of Hospital Administration ; (12): 1-5, 2018.
Artigo em Chinês | WPRIM | ID: wpr-665078

RESUMO

Objective To analyze the problems existing in the implementation of the hierarchical medical system in China under the new situation .Methods The Smith policy implementation process model was used as an analytic framework.By means of literature analysis ,stakeholder analysis and PEST analysis ,the analysis was conducted in terms of such elements as the Smith policy implementation process model ,namely ,the idealized policy ,the implementing organization ,the target group and the environmental factors ,as well as its mechanism of action .Results The literature review found that the main obstacle that hinders the smooth implementation of the hierarchical medical system was the lagging of relevant supporting measures ,which accounted for 16.6% (161)of the problems.In addition ,defects in policy design(the lack of division and cooperation mechanism etc .)and constraints in existing institutional mechanism (separation of revenue and expenditure ,unclear orientation ,etc .) were suggested to accelerate the introduction of supporting policies ,respectively accounting for 6.0%(58) and 9.3% (90 ) of the results .Conclusions In the process of policy implementation ,the relationship between the four elements of the ideal policy outcomes ,the implementing organization ,the target group and the environmental factors needs to be coordinated to ensure the effective implementation of the hierarchical medical system .

10.
National Journal of Andrology ; (12): 873-877, 2017.
Artigo em Chinês | WPRIM | ID: wpr-812865

RESUMO

Objective@#To investigate the role of pH2AX in the reversibility of mouse testicular reproductive function impaired by single heat stress.@*METHODS@#Twenty-four C57 male mice were randomly divided into heat stress and control groups and immersed in water at 43℃ and 25℃, respectively, for 15 minutes. At 1, 7, and 14 days of heat exposure, all the mice were sacrificed and their testis tissues collected for determining the apoptosis of the germ cells by TUNEL and measuring the expression level of the pH2AX protein by immunohistochemistry and Western blot.@*RESULTS@#The highest percentage of apoptotic cells were found in the seminiferous tubules of the mice in the heat stress group on the 1st day of the exposure and almost no apoptosis was observed at 7 and 14 days. The pH2AX protein was expressed in the nuclei of the basement membrane of adjacent seminiferous tubules. Compared with the control group, the expression of pH2AX was significantly increased on the 1st day of exposure (0.47 ± 0.02 vs 1.61 ± 0.04, P <0.01), then decreased at 7 days (0.85 ± 0.03) in comparison with that on the 1st day (P <0.01), and again elevated at 14 days (1.72 ± 0.02) as compared with either those at 1 and 7 days (P <0.01) or that of the control (P <0.01).@*CONCLUSIONS@#Heat stress causes dynamic changes of the pH2AX expression in the testis of the mouse, which are associated with heat stress-induced proliferation and division of the testicular spermatogenic cells.


Assuntos
Animais , Masculino , Camundongos , Apoptose , Western Blotting , Transtornos de Estresse por Calor , Histonas , Metabolismo , Temperatura Alta , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Túbulos Seminíferos , Biologia Celular , Espermatozoides , Biologia Celular , Metabolismo , Testículo , Fatores de Tempo
11.
Chinese Journal of Medical Library and Information Science ; (12): 14-21, 2017.
Artigo em Chinês | WPRIM | ID: wpr-663837

RESUMO

Objective To analyze the NIH data sharing repository in order to provide reference for the related stud-ies in biomedical data field and for the development of medical data sharing repository in China. Methods Ten typi-cal data sharing repositories ( such as UniProt, Protein Data Bank, and GenBank) were compared. Their data ac-cess methods, data management and sharing model, and service forms were summarized. Results The data manage-ment links and their process standards were designed according to their characteristics. Conclusion Data service tools can be designed, semi-artificial and semi-automatic data check can be carried out, detail meta-data can be collected, and citation rules confirming to the characteristics of data sharing repository can be established in our country by learning the experiences of NIH in developing its data sharing repository.

12.
The Journal of Clinical Anesthesiology ; (12): 136-139, 2017.
Artigo em Chinês | WPRIM | ID: wpr-510614

RESUMO

Objective To investigate the effects of autologous blood transfusion and allogeneic blood transfusion on postoperative complications and outcome of patients underwent craniotomy with traumatic brain injury.Methods All transfusional cases underwent emergency craniotomy with trau-matic brain injury from January,2012 to June,201 6,1 61 males and 38 females,ASA physical statusⅠ-Ⅳ,were respectively analyzed and divided into autologous blood group (n = 108)and allogeneic blood group (n =91)based on whether or not using cell salvage.The restrictive transfusion strategy was applied in the two groups and the red blood cells were infused to maintain the hemoglobin concen-tration at 70-100 g/L.The incidence of postoperative complications and adverse transfusion reaction were analyzed and the clinical outcome was judged by Glasgow outcome score (GOS).Results The incidence of postoperative complications (33% vs.56%,P <0.01 )and adverse transfusion reaction (5% vs.14%,P <0.05)of the autologous blood group were lower than that in the allogeneic blood group,and the clinical outcome was better (P <0.01).Logistic regression analysis showed that allo-genetic transfusion (OR =1.953,95%CI 1.381-2.529)was an independent risk factor of postopera-tive complications.Conclusion The use of autologous blood transfusion in patients with traumatic brain injury can reduce the incidence of postoperative complications and the risk of blood transfusion and improve clinical outcome.

13.
Chongqing Medicine ; (36): 5101-5102,5106, 2015.
Artigo em Chinês | WPRIM | ID: wpr-603094

RESUMO

Objective To discuss the clinical efficacy between the small skull-window microsurgical surgery and conventional trauma craniotomy in the treatment of hypertensive cerebral hemorrhage .Methods The clinical data of patients with hypertensive cerebral hemorrhage treated with two different approaches from January 2010 to October 2014 were analyzed retrospectively .Re-sults The re-hemorrhage rate of patients treated with conventional trauma craniotomy was relatively low ,compared with patients treated with small skull-window microsurgical surgery .small skull-window microsurgical surgery was superior than conventional trauma craniotomy in the incidence of postoperative complications ,disability rate and patients′ hospitalization time(P< 0 .05) .Con-clusion Small skull-window microsurgical surgery is superior than conventional trauma craniotomy .

14.
International Journal of Oral Science ; (4): 208-213, 2012.
Artigo em Inglês | WPRIM | ID: wpr-358206

RESUMO

This in vitro study aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal (Group LP), disto-buccal (Group P), mesio-lingual (Group NP) and disto-lingual (Group L) specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L* but decrease in a* and b*, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.


Assuntos
Humanos , Cor , Cristalografia , Esmalte Dentário , Efeitos da Radiação , Durapatita , Efeitos da Radiação , Peróxido de Hidrogênio , Farmacologia , Concentração de Íons de Hidrogênio , Iluminação , Teste de Materiais , Microscopia Eletrônica de Varredura , Dióxido de Silício , Farmacologia , Análise Espectral , Clareamento Dental , Métodos , Clareadores Dentários , Classificação , Farmacologia , Desmineralização do Dente , Patologia , Difração de Raios X
15.
Chinese Journal of Primary Medicine and Pharmacy ; (12): 2472-2473, 2010.
Artigo em Chinês | WPRIM | ID: wpr-386602

RESUMO

Objective To discuss the technical factors of extrapleural locating in CT-guided percutaneous pulmonary biopsy. Methods 137 cases undervent CT-guided percutaneous pulmonary biopsy were retrospectively analyzed. The technical methods of operation,points and points for attention were analyzed. Results In this group the success rate of data manipulation was 98.5%. No serious complications of the operation were occured. Scan completed within 40-story biopsy rate was 71.5%. The needle into the target rate for the first time was 93.4%. Conclusion CT-guided biopsy could increase the detection rate of difficult lesions and patient satisfaction rate paying attention on thinking and practice in the preoperative preparation and intraoperative specific operations.

16.
Chinese Journal of Contemporary Pediatrics ; (12): 460-463, 2009.
Artigo em Chinês | WPRIM | ID: wpr-304680

RESUMO

<p><b>OBJECTIVE</b>To investigate the feeding patterns of infants in Huining County, Gansu Province, an economically undeveloped county in China, so as to provide scientific evidence for nutritional intervention.</p><p><b>METHODS</b>By cluster sampling based on the area distribution and the economic state, 437 children from 7 different areas in Huining County, Gansu Province were enrolled. A questionnaire on the feeding patterns within 24 months of age was completed by the caregivers. The addition of nutrient supplements (calcium, zinc, ferri, vitamin AD, etc.) during the last year was investigated using the food frequency questionnaires.</p><p><b>RESULTS</b>The average percentages of breast feeding, mixed feeding and artificial feeding were 45.3%, 40.5% and 14.2% respectively. Delayed introduction of complementary food was the most common. Formula powder was added earliest, at age of 6.4 months. The meats were added latest, at age of 17.2 months. Only 66.8% of infants received an addition of complementary food at age of 4-6 months. Grains, vegetables, fruits and eggs were common complementary additional diets, but fishes and shrimps were seldom provided. The proportion of nutrient supplement use was low. The choice of nutrient supplements in urban districts mainly depended on the physicians' suggestions, but in rural area it depended on the caregivers' experience and media advertisements.</p><p><b>CONCLUSIONS</b>The feeding patterns for the infants are not reasonable in Huining County, Gansu Province. It is important to provide nutritional education and reasonable feeding program for caregivers from economically undeveloped areas.</p>


Assuntos
Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Aleitamento Materno , Suplementos Nutricionais , Comportamento Alimentar , Fenômenos Fisiológicos da Nutrição do Lactente
17.
Chinese Journal of Biotechnology ; (12): 71-77, 2005.
Artigo em Inglês | WPRIM | ID: wpr-256109

RESUMO

An alkaline catalase has been purified and characterized from a slightly halophilic and alkaliphilic bacterium Bacillus sp. F26. The purification was performed with a four step procedure consisting of ammonium sulfate precipitation, ion exchange, gel filtration and hydrophobic interaction chromatography, and finally achieved a 58.5-fold-purifying over the crude extract. The purified catalase was composed of two identical subunits with a native molecular mass of 140 kD. The native enzyme showed the typical Soret band appearing at 408 nm. The pyridine hemochrome spectrum indicated the presence of protoheme IX as the prosthetic group. The apparent Km value for enzyme activity on H2O2 was calculated to be 32.5 mmol/L. The activity of this catalase was not reduced by dithionite but was strongly inhibited by cyanide, azide, and 3-amino-1,2,4-triazole (the specific inhibitor of monofunctional catalase). No peroxidase activity of this enzyme was detected when using o-dianisidine, diaminobenzidine (DAB) and p-phenylenediamine as electron donor. Moreover, the N-terminal sequence of this catalase exhibited substantial similarity to the monofunctional catalase subgroup rather than catalase-peroxidase or Mn-catalase one. Therefore, we characterize the purified catalase as a monofunctional catalase. Besides, this monofunctional catalase was thermosensitive and its activity exhibited pH-independent over pH 5-9 but showed a sharp maximum at pH 11. An activity half-life of approximately 49 h was measured when the enzyme was incubated at 20 degrees C and pH 11. To our knowledge, pH 11 is the most alkaline condition for optimum catalysis and enzyme stability among the catalases reported up to now. Furthermore, this monofunctional catalase also showed excellent halo-alkali-stability with a half-life of approximately 90 h at 0.5 mol/L NaCl and pH 10.5. On the other hand, so far as we know, the characterized catalase is the first dimeric monofunctional catalase from alkaliphiles and is also the first monofunctional catalase derived from a natural soda lake, which could partially reflect the oxidative stress response in the corresponding environment.


Assuntos
Bacillus , Proteínas de Bactérias , Química , Catalase , Química , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA