Expression of recombinant PreS2-S protein from the hepatitis B virus surface antigen in Pichia pastoris

The aim of this work is the expression of the PreS2-S region of surface antigen of hepatitis B virus (HBV) in yeast Pichia pastoris. A cDNA fragment encoding the Pres2-S protein of HBV was cloned to yeast transfer vectors. Based on cloned new plasmids pPIC3.5-PreS2-S (8707 bp) and pPIC9-PreS2-S (8980 bp) the recombinant strains of P. pastoris producing the PreS2-S region of surface antigen of HBV were obtained. The PAGE electrophoresis and immunoblotting of obtained recombinant PreS2-S protein confirm the molecular weight (34 kDa) and high specificity to the HBV antibodies)AU)

El objetivo de este trabajo es la expresión de la región PreS2-S del antígeno de superficie del virus de la hepatitis B en la levadura Pichia pastoris. Se clonó un fragmento de ADNc que codifica la proteína PreS2-S del VHB en vectores de transferencia de levadura. A partir de los nuevos plásmidos clonados pPIC3.5-PreS2-S (8707 pb) y pPIC9-PreS2-S (8980 pb) se obtuvieron las cepas recombinantes de P. pastoris productoras de la región PreS2-S del antígeno de superficie del VHB. La electroforesis PAGE y la inmunotransferencia de la proteína PreS2-S recombinante obtenida confirman el peso molecular (34 kDa) y la alta especificidad a los anticuerpos contra el VHB(AU)

Modern Fungicides: Mechanisms of Action, Fungal Resistance and Phytotoxic Effects

The establishment of safe and effective methods for controlling fungal diseases is an urgent issue in agriculture and forestry. Fungicide research has provided a wide range of products with new modes of action. Extensive use of these compounds in agriculture enhances public anxiety due to the harmful potential for the environment and human health. Moreover, the phytotoxic effects of some fungicides are already recognized but still little is known about their influence on the photosynthetic apparatus and plant physiology. This review provides an understanding of the mechanisms of action of fungicides, mechanisms of fungicide resistance development, and the phenomenon of phytotoxicity.

Variabilidade intra e interobservador no diagnóstico radiográfico de lesões periapicais de origem inflamatória / Intra and interobserver variability in radiographic diagnosis of inflammatory periapical lesions

Para avaliar a concordância e a acurácia no diagnóstico da situação do periápice de molares e prémolaresinferiores portadores ou não de patologia periapical, quarenta radiografias periapicais, vinte de dentescom vitalidade pulpar e sem radiolucências periapicais e vinte de dentes com necrose pulpar foram selecionadas,digitalizadas em scanner no modo 8 bits, com resolução de 300 dpi e armazenadas no formatoJPEG 12. As imagens digitalizadas foram apresentadas no formato de slides com fundo preto no programaPowerPoint, sendo projetadas em equipamento multimídia para vinte observadores, alunos de dois gruposde pós-graduação de uma mesma instituição de ensino, simultaneamente, com repetição de 20% dos casos.Os observadores apresentaram ampla variação do percentual de concordância entre diagnósticos repetidos,contudo, quando agrupados por especialidade, endodontistas e radiologistas apresentaram percentuais deconcordância de 62,50 e 66,25%, respectivamente. A concordância interobservadores foi superior entre osalunos de Radiologia, comparados aos de Endodontia (Kendall´s W= 0,816 e 0,662 respectivamente). Emrelação à especificidade, observou-se desempenho idêntico para os dois grupos (70 a 95%), contudo os alunosde Radiologia apresentaram sensibilidade ligeiramente superior (70 a 95%). A variabilidade, tanto intraquanto inter observador, verificada pelas analises realizadas pelos alunos da mesma especialidade sugereque os critérios de interpretação de imagens radiográficas devam ser enfatizados e um maior treinamentoaplicado nos cursos de pós-graduação.

In order to assess agreement and diagnostic accuracy in lower molars and premolars periapical radiographs,with or without apical radiolucences, in periapical region, forty radiographs, twenty of teeth withpulp vitality and without periapical radiolucences and twenty with nonvital pulp teeth were selected. Theradiographs were digitized in a scanner at 8 bits, 300 dpi and saved in JPEG 12 format. The images werepresented simultaneously to two groups of ten observers, which were post-graduation students at the sameinstitution, utilizing multimedia equipment and a PowerPoint program to project the black background slides.Twenty percent of the images were reanalyzed. The observers presented a significant agreement variationin the reanalysis; however, when grouped by of expertise, endodontists and radiologists agreed in theirdiagnosis in 62.50% and 66.25%, respectively. The interobserver agreement was higher among Radiologystudents compared to the Endodontics students (Kendall´s W= 0.816 e 0.662, respectively). In reference tospecificity, both demonstrated equal performance (70 to 95%), nonetheless the Radiology students demonstratedslightly higher sensibility (70 to 95%). Both intra and interobserver variability verified throughout theanalyses done by the students, of the same of expertise, suggest that the radiographic image interpretationcriterions should be emphasized and a better training applied in the post-graduations courses.

Partial purification of tightly bound mitochondrial hexokinase from maize (Zea mays L) root membranes

In mammals, hexokinase (HK) is strategically located at the outer membrane of mitochondria bound to the porin protein. The mitochondrial HK is a crucial modulator of apoptosis and reactive oxygen species generation. In plants, these properties related to HK are unknown. In order to better understand the physiological role of non-cytosolic hexokinase (NC-HK) in plants, we developed a purification strategy here described. Crude extract of 400 g of maize roots (230 mg protein) contained a specific activity of 0.042 æmol G6P min-1 mg PTN-1. After solubilization with detergent two fractions were obtained by DEAE column chromatography, NC-HK 1 (specific activity = 3.6 æmol G6P min-1 mg PTN-1 and protein recovered = 0.7 mg) and NC-HK 2. A major purification (yield = 500-fold) was obtained after passage of NC-HK 1 through the hydrophobic phenyl-Sepharose column. The total amount of protein and activity recovered were 0.04 and 18 percent, respectively. The NC-HK 1 binds to the hydrophobic phenyl-Sepharose matrix, as observed for rat brain HK. Mild chymotrypsin digestion did not affect adsorption of NC-HK 1 to the hydrophobic column as it does for rat HK I. In contrast to mammal mitochondrial HK, glucose-6-phosphate, clotrimazole or thiopental did not dissociate NC-HK from maize (Zea mays) or rice (Oryza sativa) mitochondrial membranes. These data show that the interaction between maize or rice NC-HK to mitochondria differs from that reported in mammals, where the mitochondrial enzyme can be displaced by modulators or pharmacological agents known to interfere with the enzyme binding properties with the mitochondrial porin protein.