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1.
Zhonghua Wai Ke Za Zhi ; 62(6): 532-536, 2024 Apr 29.
Artigo em Chinês | MEDLINE | ID: mdl-38682623

RESUMO

The current clinical treatment methods for aortic diseases including aortic aneurysm, aortic dissection,etc.,are open surgery and endovascular surgery. Compared to traditional open surgery, endovascular surgery has the advantages of minimal trauma, fast recovery, fewer complications, and better prognosis, which gradually becomes the main trend in the treatment of aortic diseases. However, with the further development and long-term follow-up of endovascular treatment for aortic diseases, increasing evidence shows that in many cases, there are difficulties in the diagnosis of causes, decision-making of treatment timing, and lack of effective evaluation of treatment prognosis in endovascular treatments. Therefore, it is necessary to conduct in-depth research on non-invasive treatment including prevention, diagnosis, treatment, and prediction of aortic diseases. The non-invasive treatment of aortic disease is mainly applied to high-risk populations with aortic dissection, regulating key targets and mechanisms, and adopting drug intervention in advance to achieve the goal of controlling aortic dilation and preventing the occurrence of dissection. Conducting precise multi omics analysis to determine the optimal intervention timing and treatment strategy and targeting complications related to aortic disease or endovascular treatment for patients with a positive family history of aortic dilation or those who have developed aortic dissection. Precise regulation can be achieved to control the progression of aortic aneurysm and aortic dissection, delay or achieve long-term stable coexistence with aortic disease, and even reverse disease progression and achieve benign aortic remodelingthrough new intervention vectors. Ultimately achieving the ideal state of complete thrombosis and mechanized healing of the aortic aneurysm or aortic dissection false lumen.

3.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 34(3): 217-222, 2022 Jul 06.
Artigo em Chinês | MEDLINE | ID: mdl-35896483

RESUMO

On February 2022, WHO released the evidence-based guideline on control and elimination of human schistosomiasis, with aims to guide the elimination of schistosomiasis as a public health problem in disease-endemic countries by 2030 and promote the interruption of schistosomiasis transmission across the world. Based on the One Health concept, six evidence-based recommendations were proposed in this guideline. This article aims to analyze the feasibility of key aspects of this guideline in Chinese national schistosomiasis control program and illustrate the significance to guide the future actions for Chinese national schistosomiasis control program. Currently, the One Health concept has been embodied in the Chinese national schistosomiasis control program. Based on this new WHO guideline, the following recommendations are proposed for the national schistosomiasis control program of China: (1) improving the systematic framework building, facilitating the agreement of the cross-sectoral consensus, and building a high-level leadership group; (2) optimizing the current human and livestock treatments in the national schistosomiasis control program of China; (3) developing highly sensitive and specific diagnostics and the framework for verifying elimination of schistosomiasis; (4) accelerating the progress towards elimination of schistosomiasis and other parasitic diseases through integrating the national control programs for other parasitic diseases.


Assuntos
Erradicação de Doenças , Esquistossomose , China/epidemiologia , Humanos , Saúde Pública , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Organização Mundial da Saúde
4.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 34(3): 241-251, 2022 Jun 16.
Artigo em Chinês | MEDLINE | ID: mdl-35896487

RESUMO

OBJECTIVE: To predict the trends for fine-scale spread of Oncomelania hupensis based on supervised machine learning models in Shanghai Municipality, so as to provide insights into precision O. hupensis snail control. METHODS: Based on 2016 O. hupensis snail survey data in Shanghai Municipality and climatic, geographical, vegetation and socioeconomic data relating to O. hupensis snail distribution, seven supervised machine learning models were created to predict the risk of snail spread in Shanghai, including decision tree, random forest, generalized boosted model, support vector machine, naive Bayes, k-nearest neighbor and C5.0. The performance of seven models for predicting snail spread was evaluated with the area under the receiver operating characteristic curve (AUC), F1-score and accuracy, and optimal models were selected to identify the environmental variables affecting snail spread and predict the areas at risk of snail spread in Shanghai Municipality. RESULTS: Seven supervised machine learning models were successfully created to predict the risk of snail spread in Shanghai Municipality, and random forest (AUC = 0.901, F1-score = 0.840, ACC = 0.797) and generalized boosted model (AUC= 0.889, F1-score = 0.869, ACC = 0.835) showed higher predictive performance than other models. Random forest analysis showed that the three most important climatic variables contributing to snail spread in Shanghai included aridity (11.87%), ≥ 0 °C annual accumulated temperature (10.19%), moisture index (10.18%) and average annual precipitation (9.86%), the two most important vegetation variables included the vegetation index of the first quarter (8.30%) and vegetation index of the second quarter (7.69%). Snails were more likely to spread at aridity of < 0.87, ≥ 0 °C annual accumulated temperature of 5 550 to 5 675 °C, moisture index of > 39% and average annual precipitation of > 1 180 mm, and with the vegetation index of the first quarter of > 0.4 and the vegetation index of the first quarter of > 0.6. According to the water resource developments and township administrative maps, the areas at risk of snail spread were mainly predicted in 10 townships/subdistricts, covering the Xipian, Dongpian and Tainan sections of southern Shanghai. CONCLUSIONS: Supervised machine learning models are effective to predict the risk of fine-scale O. hupensis snail spread and identify the environmental determinants relating to snail spread. The areas at risk of O. hupensis snail spread are mainly located in southwestern Songjiang District, northwestern Jinshan District and southeastern Qingpu District of Shanghai Municipality.


Assuntos
Ecossistema , Gastrópodes , Animais , Teorema de Bayes , China/epidemiologia , Aprendizado de Máquina Supervisionado
6.
Mol Biol (Mosk) ; 49(2): 279-88, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26065255

RESUMO

The transcriptomic profiles of human breast cancer cell lines MCF-7 and MDA-MB-435 were investigated using the next-generation RNA sequencing (RNA-Seq). The DESeq package was used to screen the differentially expressed transcripts. A total of 229 genes with a significantly differential expression in MDA-MB-435 cells as compared with MCF-7 cells were obtained. Annotation of the biological functions of these genes through the Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.7 demonstrated that the 229 differentially expressed genes were mainly implicated in the biological functions related to cell adhesion and motion, antigen processing and presentation (via MHC class II), hormone response, extracellular structure organization, tissue remodeling, and cell proliferation regulation. Analysis of the individual genes demonstrated that MDA-MB-435 cells exhibited a higher tendency to metastasis and antigen processing and presentation, and lower ability to hormone response. Twenty most abundant transcripts in MDA-MB-435 cells, such as VIM, TNC, and CD74, represent its high potential for metastasis. Besides the genes previously reported to be involved in tumor metastasis and development, genes newly identified in this study could provide new clues for the diagnosis and prognosis of aggressive breast cancers.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Transcriptoma , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Humanos , Metástase Neoplásica , Análise de Sequência de RNA
7.
Lett Appl Microbiol ; 61(1): 63-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25868395

RESUMO

UNLABELLED: One of the steroid intermediates, 4-androstene-3, 17-dione (AD), in the biotransformation of phytosterols is valuable for the production of steroid medicaments. However, its degradation during the conversion process is one of the main obstacles to obtain high yields. In this study, the effect of temperature on nucleus degradation during microbial biotransformation of phytosterol was investigated. The results indicated that microbial degradation of phytosterol followed the AD-ADD-'9-OH-ADD' pathway, and that two important reactions involved in nucleus degradation, conversions of AD to ADD and ADD to 9-OH-ADD, were inhibited at 37°C. With a change in the culture temperature from 30 to 37°C, nucleus degradation was reduced from 39·9% to 17·6%, due to inhibition of the putative KstD and Ksh. These results suggested a simple way to decrease the nucleus degradation in phytosterol biotransformation and a new perspective on the possibilities of modifying the metabolism of strains used in industrial applications. SIGNIFICANCE AND IMPACT OF THE STUDY: Nucleus degradation of products is one of the main problems encountered during phytosterol biotransformation. To solve this problem, the effect of temperature on nucleus degradation was investigated in the industrial production of steroid intermediates. The results are also helpful to the genetic modification of sterol-producing strains.


Assuntos
Androstenodiona/metabolismo , Mycobacterium/metabolismo , Fitosteróis/metabolismo , Biotransformação/fisiologia , Núcleo Celular/metabolismo , Temperatura
8.
J Appl Microbiol ; 107(1): 245-56, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19302301

RESUMO

AIMS: To clone and characterize genes encoding novel cellulases from metagenomes of buffalo rumens. METHODS AND RESULTS: A ruminal metagenomic library was constructed and functionally screened for cellulase activities and 61 independent clones expressing cellulase activities were isolated. Subcloning and sequencing of 13 positive clones expressing endoglucanase and MUCase activities identified 14 cellulase genes. Two clones carried two gene clusters that may be involved in the degradation of polysaccharide nutrients. Thirteen recombinant cellulases were partially characterized. They showed diverse optimal pH from 4 to 7. Seven cellulases were most active under acidic conditions with optimal pH of 5.5 or lower. Furthermore, one novel cellulase gene, C67-1, was overexpressed in Escherichia coli, and the purified recombinant enzyme showed optimal activity at pH 4.5 and stability in a broad pH range from pH 3.5 to 10.5. Its enzyme activity was stimulated by dl-dithiothreitol. CONCLUSIONS: The cellulases cloned in this work may play important roles in the degradation of celluloses in the variable and low pH environment in buffalo rumen. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provided evidence for the diversity and function of cellulases in the rumen. The cloned cellulases may at one point of time offer potential industrial applications.


Assuntos
Bactérias/enzimologia , Celulases/genética , Clonagem Molecular/métodos , Metagenômica , Rúmen/enzimologia , Animais , Bactérias/genética , Búfalos , Eletroforese em Gel de Poliacrilamida , Biblioteca Genômica , Rúmen/microbiologia , Análise de Sequência de DNA
9.
Eur J Pediatr Surg ; 18(4): 224-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18704890

RESUMO

OBJECTIVE: Aim of the study was to investigate the expression of OPN (osteopontin) and its upper-downstream regulating factors in the biliary atretic liver and explore the relationship to progressive intrahepatic fibro-inflammation. METHOD: OPN expression in the livers of 18 children with biliary atresia (BA), 15 children with congenital biliary dilatation (CBD) and 8 normal controls were examined by immunostaining. Masson's trichrome stain was used to evaluate the level of hepatic fibrosis in each group. Western blotting and RT-polymerase chain reaction were respectively used to semiquantitatively analyze the NF-kappaB (nuclear factor-kappaB) and the TGF-beta1mRNA (transforming growth factor-beta1) expression in each group. RESULTS: OPN expression was found in the epithelial cells of the intrahepatic bile duct in the BA group, and its intensity was 0.33 +/- 0.10, while there was only little expression of OPN in the epithelial cells of the intrahepatic bile ducts in the CBD group and normal controls. There was a positive correlation between the intensity of OPN and the level of hepatic fibrosis in BA livers (r = 0.97). The intensity of NF-kappaB expression in BA livers (0.76 +/- 0.07) was much higher than that in CBD livers (0.25 +/- 0.04) or the livers of normal controls (0.22 +/- 0.02). A positive correlation was detected between the intensity of NF-kappaB and OPN in BA livers (r = 0.94). The expression of TGF-beta1mRNA in BA livers (1.46 +/- 0.17) was much higher than that in CBD livers (0.68 +/- 0.11). Little expression of TGF-beta1mRNA was detected in the livers of normal controls. A positive correlation was detected between the expression of TGF-beta1mRNA and the intensity of OPN in BA livers (r = 0.88). CONCLUSION: The abnormal activation of the OPN inflammation pathway might play a key role in the generation of intrahepatic fibrosis in BA. This progressive fibro-inflammation might be controlled by OPN and its upper-downstream regulating factors NF-kappaB and TGF-beta1.


Assuntos
Atresia Biliar/metabolismo , Cirrose Hepática/metabolismo , Fígado/metabolismo , NF-kappa B/metabolismo , Osteopontina/metabolismo , Ductos Biliares Intra-Hepáticos/metabolismo , Criança , Progressão da Doença , Humanos , Imuno-Histoquímica , Lactente , Fator de Crescimento Transformador beta1/metabolismo
10.
Kidney Int ; 71(9): 901-11, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17342181

RESUMO

Diet-derived advanced glycation end products (AGEs) contribute significantly to accumulation of AGEs in renal insufficiency. To test whether modulation of dietary AGEs would impact on progression of chronic renal disease, 5/6 nephrectomy rats were randomly placed on three diets that differed only in AGEs content (low AGEs diet (LAD), high AGEs diet (HAD), and standard rodent diet (SRD)) for 5-13 weeks. Compared with SRD- or HAD-fed rats, LAD-treated animals showed decreased proteinuria and retarded decline of creatinine clearance without alteration of blood pressure. Glomerular volume was reduced by 23% compared with HAD-fed rats at week 13 (P<0.001). Renal fibrosis progressed with time in the remnant kidneys from HAD-fed rats. However, LAD-fed animals presented a better-preserved structure of the kidneys. LAD-fed rats demonstrated significantly decreased serum and renal AGEs concentration (P<0.01 and P<0.01). This was associated with marked decrease of intrarenal advanced oxidation protein products and thiobarbituric acid reactive substances, as well as increase of glutathione peroxidase activity. LAD treatment also downregulated expression of monocyte chemoattractant protein-1 and transforming growth factor-1 and ameliorated macrophage infiltration in the remnant kidney. These results demonstrated that restriction of dietary AGEs intake retards progression of renal fibrosis and dysfunction in the remnant kidney model.


Assuntos
Dieta , Produtos Finais de Glicação Avançada/farmacologia , Rim/patologia , Proteinúria/prevenção & controle , Animais , Creatinina/metabolismo , Progressão da Doença , Produtos Finais de Glicação Avançada/administração & dosagem , Inflamação/prevenção & controle , Rim/fisiopatologia , Testes de Função Renal , Masculino , Modelos Animais , Estresse Oxidativo , RNA/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Biosci Biotechnol Biochem ; 64(12): 2614-24, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11210125

RESUMO

The nucleotide sequence of the Clostridium josui FERM P-9684 xyn10A gene, encoding a xylanase Xyn10A, consists of 3,150 bp and encodes 1,050 amino acids with a molecular weight of 115,564. Xyn10A is a multidomain enzyme composed of an N-terminal signal peptide and six domains in the following order: two thermostabilizing domains, a family 10 xylanase domain, a family 9 carbohydrate-binding module (CBM), and two S-layer homologous (SLH) domains. Immunological analysis indicated the presence of Xyn10A in the culture supernatant of C. josui FERM P-9684 and on the cell surface. The full-length Xyn10A expressed in a recombinant Escherichia coli strain bound to ball-milled cellulose (BMC) and the cell wall fragments of C. josui, indicating that both the CBM and the SLH domains are fully functional in the recombinant enzyme. An 85-kDa xylanase species derived from Xyn10A by partial proteolysis at the C-terminal side, most likely at the internal region of the CBM, retained the ability to bind to BMC. This observation suggests that the catalytic domain or the thermostabilizing domains are responsible for binding of the enzyme to BMC. Xyn10A-II, the 100-kDa derivative of Xyn10A, was purified from the recombinant E. coli strain and characterized. The enzyme was highly active toward xylan but not toward p-nitrophenyl-beta-D-xylopyranoside, p-nitrophenyl-beta-D-cellobioside, or carboxymethylcellulose.


Assuntos
Clostridium/genética , Xilosidases/genética , Xilosidases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Domínio Catalítico , Celulose/metabolismo , Clonagem Molecular , Clostridium/enzimologia , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Biossíntese de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência , Homologia de Sequência de Aminoácidos , Xilano Endo-1,3-beta-Xilosidase , Xilosidases/imunologia
12.
J Cancer Res Clin Oncol ; 125(1): 28-34, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10037274

RESUMO

PURPOSE: To study the relationship between intercellular adhesion molecule 1 (ICAM-1) and liver cancer metastasis and to find predicting factors that could indicate the growth and metastasis of liver cancer. METHODS: ICAM-1 expression in fresh tissue of normal liver and hepatocellular cancer (HCC) was examined by immunoperoxidase staining. Serum soluble intercellular adhesion molecule 1 (sICAM-1) from patients with a benign HCC tumor, and the expression of ICAM-1 in the orthotopically transplanted LCI-D20 tumor of a nude mouse liver cancer metastasis model, and in human hepatoma, the tumor surrounding tissue and normal liver, was analyzed semiquantitatively by the immuno-dot blot method. Tissue ICAM-1 expression (mRNA level) was detected by Northern blotting. RESULTS: ICAM-1 expression in LD1-20 D metastatic liver cancer had a positive correlation with tumor size and the time after implantation. It increased suddenly as metastasis occurred being 3.03+/-0.51 before metastasis and 8.24+/-0.95 after metastasis, P < 0.01, then remained high, appending on the number of sites involved (monosite metastasis 5.48+/-0.49, multisite metastasis 10.05+/-1.17, P < 0.05). All six cases of normal liver samples were negative in anti-ICAM-1 immunohistochemical staining, 80.0% (36/45) of the HCC showed some ICAM-1 expression. The rate of positive cells was a little higher in large tumors, tumors with an intact capsule and tumors with metastasis, but there was no significant difference. It was noticed that two cancer emboli also had high ICAM-1 expression. The ICAM-1 concentration in HCC (13.43+/-0.09) was higher than that in tumor surrounding the liver (5.89+/-0.17, P < 0.01) and that in normal liver (4.27+/-0.21, P < 0.01). sICAM-1, like tissue ICAM-1, was higher in HCC patients than in patients (with benign liver tumor and normal controls. Both tissue ICAM-1 and sICAM-1 were higher in the metastasis group than in the group without metastasis (tissue ICAM-1 20.24+/-0.30 vs 10.23+/-0.12 P < 0.05; sICAM-1 12.18+/-0.25 vs 9.77+/-0.54 P < 0.05). Northern blot analysis revealed that ICAM-1 expression, as indicated by mRNA level, was also higher in HCC and in cancer emboli than in tumor surrounding liver and normal liver. CONCLUSIONS: Tissue ICAM-1 and serum sICAM-1 could indicate the stage of HCC, and the potential of hepatoma cells for invasion and metastasis. They may play an important role in the metastasis cascade.


Assuntos
Carcinoma Hepatocelular/metabolismo , Molécula 1 de Adesão Intercelular/biossíntese , Neoplasias Hepáticas/metabolismo , Animais , Northern Blotting , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/secundário , Membrana Celular/metabolismo , Expressão Gênica , Humanos , Imuno-Histoquímica , Molécula 1 de Adesão Intercelular/sangue , Molécula 1 de Adesão Intercelular/genética , Fígado/metabolismo , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Células Neoplásicas Circulantes/metabolismo , RNA Mensageiro/análise , Fatores de Tempo
13.
Mol Microbiol ; 28(5): 961-70, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9663682

RESUMO

Xanthomonas campestris pv campestris (Xcc) is a plant pathogenic bacterium that controls the production of pathogenicity factors in part by a cluster of genes designated rpf (regulation of pathogenicity factors). Sequence analysis of one of these genes (rpfA) revealed an open reading frame with amino acid sequence similarity to aconitases from other bacteria. Aconitase activity was lower in cellular extracts of an rpfA::Tn5 mutant than in those from the wild type. A zymogram of aconitase activity after native gel electrophoresis showed the presence of two distinct aconitases in Xcc; the major aconitase was absent in the rpfA::Tn5 mutant. This mutant also had reduced levels of extracellular enzymes and extracellular polysaccharide (EPS). Supplying rpfA in trans to the rpfA::Tn5 mutant restored both the major aconitase activity and the synthesis of these pathogenicity factors. The transcription of the genes for two extracellular enzymes (prtA, encoding a serine protease, and engXCA, encoding endoglucanase) was reduced in the rpfA mutant background. Because some eukaryotic aconitases are also involved in iron regulation, we explored a possible connection between rpfA and iron metabolism. Intracellular iron levels in the mutants were lower than in the wild type as assessed by sensitivity to the iron-activated antibiotic, streptonigrin. Wild-type bacteria grown in iron-deficient conditions had a similar sensitivity to streptonigrin as the aconitase mutant. Overall, these results suggest that a prokaryotic aconitase can also act as a regulator of gene expression and that the regulation is possibly related to changes in intracellular iron levels.


Assuntos
Aconitato Hidratase/genética , Proteínas de Bactérias/genética , Genes Bacterianos , Isoenzimas/genética , Xanthomonas campestris/enzimologia , Aconitato Hidratase/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/metabolismo , Sequência de Bases , DNA Bacteriano , Resistência Microbiana a Medicamentos , Teste de Complementação Genética , Humanos , Isoenzimas/metabolismo , Dados de Sequência Molecular , Mutagênese , Coelhos , Análise de Sequência de DNA , Estreptonigrina/farmacologia , Transcrição Gênica , Xanthomonas campestris/efeitos dos fármacos , Xanthomonas campestris/genética
14.
J Automat Chem ; 20(1): 17-21, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-18924817

RESUMO

A flow injection configuration (FIA) based on a galvanic detector for the determination of nitrogen dioxide is described. The gaseous sample is directly injected into a gaseous carrier. The sample is transported toward the detector. The steady state measurements are not required to obtain the reproducible peak signals. The features of FIA are compared with that of continuous flow monitoring application. The flow injection system is simple, rapid and capable of detecting NO(2) in the range of 1-500ppm (v/v). The measuring range and sensitivity of the galvanic detector in FIA depend on the sample volume. A relative standard deviation is 2.4% (n = 10) for 200ppm (v/v) of nitrogen dioxide. The sampling frequency is about 24 h(-1).

15.
Mol Microbiol ; 24(3): 555-66, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9179849

RESUMO

Mutations in the seven clustered rpf genes cause downregulated synthesis of extracellular enzymes and reduced virulence of Xanthomonas campestris pathovar campestris (Xcc). The phenotype of mutants in one of the genes, rpfF, can be restored by a diffusible extracellular factor (DSF) produced by all Xcc strains tested, apart from rpfF and rpfB mutants. DSF accumulates in early stationary phase (when synthesis of enzymes is maximal), but levels decline subsequently. Addition of DSF to exponentially-growing wild-type bacteria does not cause precocious enzyme synthesis. rpfB and rpfF are expressed throughout growth, but the rate increases in early stationary phase. RpfB is predicted to be a long-chain fatty acyl CoA ligase, and RpfF shows some relatedness to enoyl CoA hydratases. The properties of DSF suggest that it may be a fatty-acid derivative, and certain lipid preparations possess DSF activity at higher concentrations. These include lipid extracts and acid-hydrolysed lipoplysaccharide and lipid A from Xcc, and purified dodecanoic and hydroxydodecanoic acid. DSF production is confined to certain xanthomonads. We propose a model for the DSF system, which represents a novel mechanism for regulating virulence factor synthesis in response to physiological or environmental changes.


Assuntos
Xanthomonas campestris/patogenicidade , Difusão , Regulação Bacteriana da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Genes Bacterianos , Cinética , Modelos Biológicos , Família Multigênica , Mutação , Fenótipo , Transdução de Sinais , Virulência/genética , Xanthomonas campestris/genética , Xanthomonas campestris/metabolismo
16.
Mol Plant Microbe Interact ; 9(7): 664-6, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8810082

RESUMO

rpfC is one of a cluster of genes which coordinately regulate the synthesis of extracellular enzymes and exopolysaccharide and pathogenicity in Xanthomonas campestris pv. campestris, the black rot pathogen of brassicas. An rpfC homolog which could functionally complement an rpfC mutant of X. campestris pv. campestris was identified in Xanthomonas oryzae pv. oryzae and the gene was characterized. Mutation of this gene in X. oryzae pv. oryzae had no effect on extracellular enzymes, but exopolysaccharide synthesis and virulence to rice were substantially reduced.


Assuntos
Proteínas de Bactérias/genética , Oryza/microbiologia , Polissacarídeos Bacterianos/biossíntese , Xanthomonas/genética , Xanthomonas/patogenicidade , Proteínas de Bactérias/biossíntese , Clonagem Molecular , Dados de Sequência Molecular , Mutagênese , Fases de Leitura Aberta , Doenças das Plantas , Proteínas Recombinantes/biossíntese , Mapeamento por Restrição , Virulência , Xanthomonas campestris/genética
17.
Brain Res ; 475(2): 333-44, 1988 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-3145783

RESUMO

Pressure-ejection of 100 mM KCl was used to induce voltammetric signals in the rat caudate. The signals, detected chronoamperometrically with Nafion-coated carbon fiber microelectrodes, were reproducibly generated at 20-min intervals up to distances of 1600 micron from the KCl stimulus site. Unilateral 6-hydroxydopamine lesions of the substantia nigra (SN) demonstrated that over 90% of the voltammetric signal generated was dopamine. Evaluation of the signal onset at two widely spaced electrodes suggested that injection of nl volumes of 100 mM KCl into the rat caudate generates voltammetric signals which resemble spreading depression (SD) produced by more classical methods (e.g. 1 M KCl). We further investigated this phenomenon by simultaneous evaluation of extracellular K+ ion concentration changes, field potential (FP) and voltammetric signals or multiunit activity following stimulation with 100 mM or 1 M KCl. The results show that the signals generated by 100 mM KCl have many of the attributes of 'classical' SD, although the extracellular K+ ion concentration changes and FP changes were smaller in magnitude. However, the characteristic burst of multiunit activity followed by a marked quiescent period found during 1 M KCl stimulation was not observed with 100 mM KCl stimulation. Furthermore, application of 0.5% lidocaine to the SN reversibly blocked all signals generated by 100 mM KCl in the caudate while similar treatment with up to 2% lidocaine was ineffective when 1 M KCl was used as the stimulus. The results suggest that the signals generated by 100 mM KCl may represent an attenuated form of SD which requires a functioning SN, and that this stimulation could be a useful model for studying neurotransmitter interactions in the propagation of the SD phenomena.


Assuntos
Núcleo Caudado/fisiologia , Dopamina/fisiologia , Lidocaína/farmacologia , Inibição Neural/efeitos dos fármacos , Cloreto de Potássio/farmacologia , Substância Negra/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Núcleo Caudado/efeitos dos fármacos , Dopamina/metabolismo , Hidroxidopaminas , Masculino , Oxidopamina , Ratos , Ratos Endogâmicos , Substância Negra/efeitos dos fármacos
19.
Yao Xue Xue Bao ; 19(4): 268-73, 1984 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-6496103
20.
Acta Chir Scand Suppl ; 508: 185-95, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6952678

RESUMO

Soft tissue wounds of hind limbs were engendered in 64 dogs by shooting rifle bullets of 5.56 and 7.62 mm calibres at a range of twenty meters with impact velocities ranging from 516.7 m/s to 959.7 m/s. Gross and microscopical examinations of these wounds were then made. The main results were as follows: 1. At conventional velocity, the injuries caused by 5.56 mm bullets were much more severe than those caused by 7.62 mm bullets. The reason for this is that the former has greater velocity and liability to tumbling, breaking or deformation in tissues. 2. The gunshot wound track presented itself in three parts: a primary wound track, a contusion zone and a concussion zone. The mean maximum diameter of primary wound track was 1.16 to 3.34 cm and the thickness of contusion zone was about 0.5 cm. Sometimes there was no definite demarcation between the contusion zone and the concussion zone found by conventional histological examination. The thickness of the contusion zone measured grossly was usually greater than that measured microscopically. 3. Perfusion of arteries of the injured legs with Chinese ink proved to be a useful method for determining the demarcation between the contusion zone and the concussion zone. 4. Pathological changes in the three zones were described in detail and the mechanism of wounding was discussed.


Assuntos
Membro Posterior/lesões , Ferimentos por Arma de Fogo/patologia , Animais , Cães , Feminino , Membro Posterior/patologia , Masculino , Infecção dos Ferimentos/etiologia , Infecção dos Ferimentos/patologia , Ferimentos por Arma de Fogo/complicações
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