RESUMO
El presente trabajo tiene por objetivo presentar los avances investigativos obtenidos al estudiar diversas problemáticas referidas a las áreas de salud, educación y justicia, desde el marco de la Resiliencia y la Calidad de Vida. El eje de análisis en estas áreas comprende el estudio de aquellos factores de riesgo y de protección que interactúan otorgando características específicas a cada una de las transiciones ecológicas estudiadas. Se analizan la discapacidad motora, el proceso de morir cuando la enfermedad ya no responde a las medidas curativas, la internación del recién nacido en la Unidad de Cuidados Intensivos Neonatológicos, la transición por la que atraviesan los jóvenes al pasar del nivel primario al secundario, y la privación de libertad. Por transiciones ecológicas se entiende los cambios en la posición de una persona dentro del ambiente ecológico en el que está inmersa, como consecuencia de un cambio de rol, de entorno, o de ambos a la vez (Bronfenbrenner, 1987). El desafío será entonces, desde el enfoque señalado, valorar en cada situación, la eficacia y funcionalidad de los recursos y factores presentes, así como también, aquellos que pueden ser promovidos a través de estrategias que revaloricen el Potencial Resiliente y la Calidad de Vida de cada persona frente a la adversidad.
Assuntos
Humanos , Qualidade de Vida/psicologia , Ecologia Humana , Argentina , Seguridade Social/psicologiaRESUMO
El presente trabajo tiene por objetivo presentar los avances investigativos obtenidos al estudiar diversas problemáticas referidas a las áreas de salud, educación y justicia, desde el marco de la Resiliencia y la Calidad de Vida. El eje de análisis en estas áreas comprende el estudio de aquellos factores de riesgo y de protección que interactúan otorgando características específicas a cada una de las transiciones ecológicas estudiadas. Se analizan la discapacidad motora, el proceso de morir cuando la enfermedad ya no responde a las medidas curativas, la internación del recién nacido en la Unidad de Cuidados Intensivos Neonatológicos, la transición por la que atraviesan los jóvenes al pasar del nivel primario al secundario, y la privación de libertad. Por transiciones ecológicas se entiende los cambios en la posición de una persona dentro del ambiente ecológico en el que está inmersa, como consecuencia de un cambio de rol, de entorno, o de ambos a la vez (Bronfenbrenner, 1987). El desafío será entonces, desde el enfoque señalado, valorar en cada situación, la eficacia y funcionalidad de los recursos y factores presentes, así como también, aquellos que pueden ser promovidos a través de estrategias que revaloricen el Potencial Resiliente y la Calidad de Vida de cada persona frente a la adversidad.(AU)
Assuntos
Humanos , Qualidade de Vida/psicologia , Ecologia Humana , Seguridade Social/psicologia , ArgentinaRESUMO
A mutation in the ilvC gene of Sinorhizobium meliloti 1021 determines a symbiotically defective phenotype. ilvC mutants obtained from different S. meliloti wild-type strains are able to induce root hair deformation on alfalfa roots and show variable activation of the common nodulation genes nodABC. All of these mutants are noninfective. The presence of extra copies of nodD3-syrM in an IlvC- background does not promote nod expression but allows the detection of low levels of Nod factor production. The sulphation of the Nod factor metabolites, however, is not affected. Furthermore, IlvC- strains induce a specific pattern of starch accumulation on alfalfa roots as well as of early nodulin expression. Hence, the pleiotropic action of the ilvC gene in S. meliloti may reveal novel complexities involved in the symbiotic interaction.
Assuntos
Medicago sativa/microbiologia , Sinorhizobium meliloti/genética , Oxirredutases do Álcool/genética , Genes Bacterianos , Cetol-Ácido Redutoisomerase , Medicago sativa/citologia , Medicago sativa/metabolismo , Proteínas dos Microtúbulos/genética , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Sinorhizobium meliloti/enzimologia , SimbioseRESUMO
Several unresolved issues still cast doubts on the epidemiological data which point to an association between infection from Helicobacter pylori (Hp) and gastric cancer. These are: a) the male/female ratio of gastric cancer ranges from 4 to 1.5 in all studies, whereas the prevalence of Hp infection is the same in both sexes; b) the prevalence of Hp infection is as high as 90% in several developing countries where the frequency of gastric cancer is very low; c) the acquisition of the infection at a young age, considered very important with regard to the risk for cancer, varies from 4.2% to 83% in several countries in which the mortality for stomach cancer is, on the average, 10/100,000; d) the incidence of cancer in patients with a duodenal ulcer is half of that of the general population but Hp infects up to 100% of these patients. In the sequence of events that lead to gastric cancer, Hp appears to play a role only in the very initial steps, as a causative agent of chronic inflammation. The further events which lead to cancer are multifactorial, involving environmental agents and the host response. It is therefore inappropriate to consider Hp a direct carcinogen for humans. This also applies to specific strains of the bacterium such as the ones expressing the cagA gene. In a study we conducted in an area with a low incidence of gastric cancer (Latina), the prevalence of Hp infection was equal to 78.6% and, among the positives, 81% resulted cagA positive. This data, if compared with a similar research that took place in another area with a high incidence of gastric cancer (San Marino) where the prevalence of Hp infection was 51% and cagA 69%, further demonstrates the inconsistency of associating Hp and cancer of the stomach.
Assuntos
Infecções por Helicobacter/complicações , Helicobacter pylori , Neoplasias Gástricas/etiologia , Adulto , África/epidemiologia , Fatores Etários , Ásia/epidemiologia , Austrália/epidemiologia , Estudos de Coortes , Colômbia/epidemiologia , Estudos Transversais , Europa (Continente)/epidemiologia , Feminino , Infecções por Helicobacter/epidemiologia , Humanos , Itália/epidemiologia , Masculino , Panamá/epidemiologia , Fatores de Risco , Fatores Sexuais , Neoplasias Gástricas/epidemiologia , Estados Unidos/epidemiologiaRESUMO
The prevalence of pre-cancerous lesions of the oesophagus and their association with alcohol and tobacco were examined in an endoscopic survey carried out in La Plata, Argentina. The study included 406 subjects over 15 years of age attending several gastroenterology clinics because of various gastrointestinal symptoms. Among males, the prevalence rates of chronic oesophagitis, epithelial atrophy and dysplasia were 42%, 3.8% and 2.4% respectively, and in females these prevalences were 36%, 2.5% and 0.0%. The presence of these pre-cancerous lesions was significantly associated with alcohol drinking and tobacco smoking.
Assuntos
Neoplasias Esofágicas/epidemiologia , Lesões Pré-Cancerosas/epidemiologia , Adolescente , Adulto , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Argentina/epidemiologia , Neoplasias Esofágicas/patologia , Esofagite/epidemiologia , Esofagite/patologia , Esofagoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/patologia , Prevalência , Fumar/efeitos adversos , Fumar/epidemiologiaRESUMO
Chaperonins (Cpn) are implicated in the folding and assembly of multimeric proteins in plastids and mitochondria of eukaryotes and in prokaryotes. Plastid Cpn is composed of two different polypeptides termed Cpn60 alpha and Cpn60 beta. We have isolated cDNA and genomic clones encoding Cpn60 beta from Arabidopsis thaliana. The steady-state level of the cpn60 beta mRNAs is higher in etiolated leaves and sucrose-treated plants as compared to control leaves. The A. thaliana cpn60 beta gene family consists of at least three different coding units. It was confirmed that Cpn beta-encoding genes have a high level of conservation among plants.
Assuntos
Proteínas de Plantas/genética , Plantas/genética , Proteínas/genética , Sequência de Aminoácidos , Sequência de Bases , Northern Blotting , Southern Blotting , Chaperoninas , Regulação da Expressão Gênica/efeitos dos fármacos , Dados de Sequência Molecular , Mapeamento por Restrição , Sacarose/farmacologiaRESUMO
When wheat (Triticum aestivum) seedlings are exposed to a cold temperature (2-4 degrees C) above 0 degrees C, sucrose accumulates and sucrose synthase activity increases. The effect of a cold period on the level of sucrose synthase (SS) was investigated. Using antibodies against wheat germ SS, Western blots studies showed that the amount of the SS peptide increased during 14 days in the cold, when plants were moved from 23 degrees C to 4 degrees C. The level of SS diminished when plants were moved back to 23 degrees C. Northern blots of poly(A)(+) RNA, confirmed a five- to sixfold induction of SS in wheat leaves during cold acclimation. These results indicate that SS is involved in the plant response to a chilling stress.
RESUMO
The activities of topoisomerases I and II were assayed in subcellular extracts obtained from nontumorigenic BALB/c 3T3 A31 and normal rat kidney (NRK) cell lines and from the same cells transformed by benzo[a]pyrene (BP-A31), Moloney (M-MSV-A31) and Kirsten (K-A31) sarcoma viruses, and simian virus 40 (SV-NRK). The enzymatic activity of topoisomerase I was monitored by the relaxation of negatively supercoiled pBR322 DNA and by the formation of covalent complexes between 32P-labeled DNA and topoisomerase I. Topoisomerase II activity was determined by decatenation of kinetoplast DNA (k-DNA). It was found that nuclear and cytoplasmic type I topoisomerase specific activities were higher in every transformed cell line than in the normal counterparts. These differences cannot be attributed to an inhibitory factor present in A31 cells. When chromatin was treated at increasing ionic strengths, the 0.4 M NaCl extract showed the highest topoisomerase I specific activity. Moreover, in this fraction the transformed cells exhibited the most significant increment in the enzymatic activity as compared with nontransformed cultures. Spontaneously transformed A31 cells showed topoisomerase I activity similar to that of extracts of cells transformed by benzo[a]pyrene. Topoisomerase II specific activity was also increased in SV-NRK cells, as judged by the assay for decatenation of k-DNA to yield minicircle DNA.
Assuntos
Transformação Celular Neoplásica/enzimologia , Transformação Celular Viral , DNA Topoisomerases Tipo I/metabolismo , Animais , Benzo(a)pireno/farmacologia , Adesão Celular , Núcleo Celular/enzimologia , Transformação Celular Neoplásica/efeitos dos fármacos , Camundongos , Novobiocina/farmacologia , RatosRESUMO
The action of luteinizing hormone on topoisomerase I activity from rat Leydig cells was studied. Stimulation of the enzyme was observed after long-term (24 and 48 h) gonadotrophin treatment in in vivo experiments. No change could be detected for shorter times than 12 h using two different experimental approaches. Topoisomerase I was stimulated by cAMP in a whole cell extract in a phosphorylation-dependent manner. These results suggest that topoisomerase I could be a target for nuclear events induced by peptide hormone action.
Assuntos
AMP Cíclico/fisiologia , DNA Topoisomerases Tipo I/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Células Intersticiais do Testículo/enzimologia , Hormônio Luteinizante/fisiologia , Animais , Proteínas de Transporte/farmacologia , Gonadotropinas/farmacologia , Técnicas In Vitro , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos , Testosterona/sangueRESUMO
Thermal injury resulting from drinking very hot beverages has been incriminated as a risk factor for oesophageal cancer, although no information is available on the lesions caused by this injury in human or experimental animals. The drinking of hot maté tea is very common in areas of moderately high incidence of oesophageal cancer in south-eastern areas of South America. This study investigated the prevalence of precancerous lesions of the oesophagus in 60 unskilled male workers, of whom half were daily maté drinkers and the remainder were non-maté drinkers. These 2 groups were matched for age, smoking and alcohol intake. Maté drinkers were 2.2 times more likely (p = 0.046) to develop histologically confirmed oesophagitis than non-maté drinkers.
Assuntos
Bebidas/efeitos adversos , Queimaduras/complicações , Neoplasias Esofágicas/etiologia , Lesões Pré-Cancerosas/etiologia , Adulto , Brasil , Ingestão de Líquidos , Esofagite/etiologia , Esofagoscopia , Humanos , Masculino , Pessoa de Meia-Idade , RiscoRESUMO
Los rotavirus son los principales agentes responsables de las gastroenteritis virales humanas y animales. La identificación y caracterización de su genoma es necesaria para la comprensión de esta patología así como para el desarrollo de nuevos métodos de diagnóstico y, eventualmente, para la preparación de antígenos virales utilizando técnicas de DNA recombinante. Estos virus poseen un genoma formado por once fragmentos de RNA doble cadena (cd). Aquí se describe la construcción de bancos de cDNA para rotavirus bovino y humano, ambos purificados de materia fecal. Los cDNA fueron preparados por síntesis in vitro utilizando transcriptasa reversa sobre los RNAs genómicos virales, previamente poliadenilados en sus extremos 3. Los cDNAs fueron ligados a un vector plasmídico y propagados en E. coli. Se obtuvieron genotecas correspondientes a los virus bovino y humano con 500 y 100 recombinantes respectivamente. Análisis de restricción de algunos clones permitieron establecer el tamaño de los insertos correspondientes a los distintos segmentos genómicos virales. Dos de estos clones fueron caracterizados, determinándose que contienen las secuencias completas de los fragmentos 10 y 8 del virus bovino. La utilización de estos clones como sondas radioactivas nos permitió diagnosticar la presencia de rotavirus en muestras de materia fecal mediante la detección de los correspondientes RNAs. Este ensayo pudo ser utilizado para la detección viral en muestras infectadas provenientes de distintas especies
Assuntos
Bovinos , Animais , Humanos , Clonagem Molecular/métodos , DNA Recombinante , Genes Virais , Técnicas In Vitro , RNA Viral/genética , Rotavirus/genética , Antígenos Virais/isolamento & purificação , Gastroenterite/diagnósticoRESUMO
Los rotavirus son los principales agentes responsables de las gastroenteritis virales humanas y animales. La identificación y caracterización de su genoma es necesaria para la comprensión de esta patología así como para el desarrollo de nuevos métodos de diagnóstico y, eventualmente, para la preparación de antígenos virales utilizando técnicas de DNA recombinante. Estos virus poseen un genoma formado por once fragmentos de RNA doble cadena (cd). Aquí se describe la construcción de bancos de cDNA para rotavirus bovino y humano, ambos purificados de materia fecal. Los cDNA fueron preparados por síntesis in vitro utilizando transcriptasa reversa sobre los RNAs genómicos virales, previamente poliadenilados en sus extremos 3. Los cDNAs fueron ligados a un vector plasmídico y propagados en E. coli. Se obtuvieron genotecas correspondientes a los virus bovino y humano con 500 y 100 recombinantes respectivamente. Análisis de restricción de algunos clones permitieron establecer el tamaño de los insertos correspondientes a los distintos segmentos genómicos virales. Dos de estos clones fueron caracterizados, determinándose que contienen las secuencias completas de los fragmentos 10 y 8 del virus bovino. La utilización de estos clones como sondas radioactivas nos permitió diagnosticar la presencia de rotavirus en muestras de materia fecal mediante la detección de los correspondientes RNAs. Este ensayo pudo ser utilizado para la detección viral en muestras infectadas provenientes de distintas especies (AU)