Search

Resumen tomado de la publicación Diferencias en memoria de trabajo entre alumnado superdotado y talentoso y muestras comunitarias: un meta-análisis. Antecedentes: los estudiantes superdotados y con talento tienen un funcionamiento diferencial en algunas componentes de las funciones ejecutivas como la memoria de trabajo. Este meta-análisis estudia las diferencias entre estudiantes con alta capacidad intelectual y con inteligencia promedio en memoria de trabajo. Método: un total de 17 artículos con 33 estudios diferenciados fueron analizados. Se empleó un modelo de efectos aleatorios, calculando el tamaño del efecto con g de Hedges. Las variables moderadoras se analizaron empleando una meta-regresión para las continuas y ANOVA para las categóricas. Resultados: los resultados muestran un tamaño del efecto de g+=0.80 (95% CI: 0.621, 0.976) y una alta heterogeneidad (Q(32)=196.966; p

11 p.-1 tab.-8 fig., We have characterized a temperate phage (MM1) from a clinical isolate of the multiply antibiotic-resistant Spanish/American 23F Streptococcus pneumoniae clone (Spain(23F)-1 strain). The 40-kb double-stranded genome of MM1 has been isolated as a DNA-protein complex. The use of MM1 DNA as a probe revealed that the phage genome is integrated in the host chromosome. The host and phage attachment sites, attB and attP, respectively, have been determined. Nucleotide sequencing of the attachment sites identified a 15-bp core site (5'-TTATA ATTCATCCGC-3') that has not been found in any bacterial genome described so far. Sequence information revealed the presence of an integrase gene (int), which represents the first identification of an integrase in the pneumococcal system. A 1.5-kb DNA fragment embracing attP and the int gene contained all of the genetic information needed for stable integration of a nonreplicative plasmid into the attB site of a pneumococcal strain. This vector will facilitate the introduction of foreign genes into the pneumococcal chromosome. Interestingly, DNAs highly similar to that of MM1 have been detected in several clinical pneumococcal isolates of different capsular types, suggesting a widespread distribution of these phages in relevant pathogenic strains., This work was supported by grants from Dirección General de Investigación Científica y Técnica (PB96-0809) and the Comunidad Autónoma de Madrid (08.2/0014.2/98). E.G. was the recipient of a Marie Curie Research Training Grant.

9 páginas, 3 figuras -- PAGS nros. 77-85, Over 60% of bacterial infections (and up to 80% of chronic infections) are currently considered to involve microbial growth in biofilms. This peculiar form of life poses an array of problems in human clinical practice, from infections associated with the implant of prosthetic devices and dental plaque formation to diseases such as cystic fibrosis, otitis media, and endocarditis. Biofilms are also at the basis of a variety of problems in industry. This report describes the biofilms produced by Streptococcus pneumoniae. This bacterium often colonizes the upper airways in humans as a normal commensal, yet it may spread to other areas of the body, causing otitis media, pneumonia, or invasive diseases such as bacteremia and meningitis. The capacity of S. pneumoniae to form biofilms had not been explored until recently. Several newly developed in vitro systems have allowed to test the capacity of S. pneumoniae to form biofilms, and to analyze the influence of several factors, including DNA and proteins—which play a role in the virulence of this “supergerm” in the formation and development of biofilms. In this brief review, we update the knowledge available on pneumococcal biofilm formation and the unusual features of this structure, Work in the authors’ laboratory was supported by a grant from the Spanish Directorate-General for Scientific and Technical Research (SAF2006-00390). CIBER de Enfermedades Respiratorias (CIBERES) is an initiative of ISCIII

12 p.-4 fig., [EN]The study of Streptococcus pneumoniae (the pneumococcus) had been a central issue in medicine for many decades until the use of antibiotics became generalized. Many fundamental contributions to the history of microbiology should credit this bacterium: the capsular precipitin reaction, the major role this reaction plays in the development of immunology through the identification of polysaccharides as antigens, and, mainly, the demonstration, by genetic transformation, that genes are composed of DNA—the finding from the study of bacteria that has had the greatest impact on biology. Currently, pneumococcus is the most common etiologic agent in acute otitis media, sinusitis, and pneumonia requiring the hospitalization of adults. Moreover, meningitis is the leading cause of death among children in developing countries. Here I discuss the contributions that led to the explosion of knowledge about pneumococcus and also report some of the contributions of our group to the understanding of the molecular basis of three important virulence factors: lytic enzymes, pneumococcal phages, and the genes coding for capsular polysaccharides., [ES]Hasta el empleo generalizado de los antibióticos, el estudio de Streptococcus pneumoniae (el neumococo) fue un tema central en medicina durante muchas décadas. Muchas contribuciones fundamentales de la historia de la microbiología se deben a esta bacteria: la reacción capsular de la precipitina, su destacado papel en el desarrollo de la inmunología mediante la identificación de polisacáridos como antígenos, y, principalmente, la demostración, por transformación genética, de que los genes están compuestos de DNA, que supuso el mayor impacto en biología a partir del estudio de las bacterias. Actualmente, el neumococo es el agente etiológico más frecuente en procesos de infección aguda del oído medio, sinusitis y neumonía que requieren hospitalización en adultos. Además, la meningitis es una de las principales causas de muerte en los niños de países en vías de desarrollo. Esta revisión trata las contribuciones que han llevado a un elevado nivel de conocimiento sobre el neumococo y describe algunas contribuciones de nuestro grupo al conocimiento de la base molecular de los tres factores principales de la virulencia, es decir, las enzimas líticas, los fagos y los genes que codifican los polisacáridos capsulares., [PORT]Até o emprego generalizado dos antibióticos, o estudo de Streptococcus pneumoniae (o neumococo) foi um tema central em medicina durante muitas décadas. São numerosas as contribuições fundamentais na história da microbiologia devidas a esta bactéria: a reação capsular da precipitina, seu papel no desenvolvimento da imunologia através da identificação de polissacarídeos como antígenos, e, principalmente, a demonstração, pe transformação genética, que os genes são compostos por DNA, o que representou o maior impacto em biologia a partir do estudo das bactérias. Atualmente, o neumococo é o agente etiológico mais comum em processos de otite aguda, sinusites e pneumonia que requerem hospitalização em adultos. No entanto, é a meningite a causa principal de morte em países desenvolvidos e em crianças em países em vias de desenvolvimento. Nesta revisão, propomos também uma análise das contribuições que levaram ao elevado nível de conhecimento sobre o neumococo, assim como um breve relatório sobre as contribuições de nosso grupo à base molecular dos três principais fatores de virulência isto é, os enzimas líticos, os fagos os genes que codificam os polissacarídeos capsulares.

Infectious diseases currently kill more than 15 million people annually, and the WHO estimates that every year 1.6 million people die from pneumococcal diseases. Streptococcus pneumoniae (pneumococcus), a bacterium with along biological pedigree, best illustrates the rapid evolution of antibiotic resistance,which has led to major public health concern. This article discusses the molecularbasis of the two main virulence factors of pneumococcus, the capsule and cell-wall hydrolases, as well as new approaches to developing medicinal weapons for preventing pneumococcal infections. In addition, current knowledge regarding pneumococcal phages as potential contributors to virulence and the use of lytic enzymes encoded by these phages as therapeutic tools is reviewed. Las enfermedades infecciosas matan anualmente a unos 15 millones de personas y la OMS estima que 1,6 millones de esas muertes se deben a infecciones neumocócicas. Streptococcus pneumoniae (neumococo), una bacteria con una notable contribución histórica a la biología, es el mejor ejemplo que ilustra el rápido desarrollo de la resistencia a los antibióticos, lo que puede originar un grave problema sanitario. Esta revisión analiza las bases moleculares de los dos factores principales de virulencia en el neumococo, la cápsula y las hidrolasas de la pared celular y describe nuevos enfoques para el desarrollo de nuevas herramientas médicas para prevenir las infecciones neumocócicas. También se analizan el conocimiento actual de la posible contribución de los fagos de neumococo a la virulencia de esta bacteria y el uso como arma terapéutica de las enzimas líticas codificadas por estos fagos. As enfermidades infecciosas matam anualmente cêrca de 15 milhões de pessoas. A OMS estima que 1,6 milhões dessas mortes são decorrentes de infeccões pneumocócicas. Streptococcus pneumoniae (pneumococo), uma bactéria com uma notável contribuição histórica para a biologia, é o melhor exemplo que ilustra o rápido desenvolvimento da resistência aos antibióticos, o que pode originar um grave problema sanitário. Esta revisão analisa as bases moleculares dos fatores principais de virulência no pneumococo, a cápsula e as hidrolases da parede celular e descreve novos enfoques para o desenvolvimento de ferramentas médicas inovadoras para prevenir as infecções pneumocócicas. Também foi analisado o atual conhecimento da possível contribuição dos fagos de pneumococo para a virulência desta bactéria e o uso como arma terapéutica das enzimas líticas codificadas por estes fagos.

The abundant presence of temperate phages in the chromosomes of clinical isolates of Streptococcus pneumoniae has been well documented. The genome of MM1, a temperate phage of pneumococcus, has been isolated as a DNA-protein complex. The protein is covalently bound to the DNA, was iodinated in vitro with Na125I, and has an Mr of 22,000. Electron microscopy and enzymatic analyses revealed that the MM1 genome is a linear, circularly permuted, terminally redundant collection of double-stranded DNA molecules packaged via a headful mechanism. The location of the pac site appears to be downstream of the terminase, between orf32 and orf34 of the MM1 genome., La abundante presencia de fagos atenuados en el cromosoma de aislados clínicos de Streptococcus pneumoniae ha sido bien documentada. El genoma de MM1, un fago atemperado de neumococo, se ha aislado como un complejo de DNA-proteína. La proteína unida covalentemente al DNA, fue yodada in vitro con Na125I, y tiene una Mr de 22.000. La microscopia electrónica y los análisis enzimáticos revelaron que el genoma de MM1 es una colección de moléculas lineales de DNA de doble cadena, permutadas circularmente y redundantes en la posición terminal, empaquetadas mediante un mecanismo de ensamblado de unidades genómicas discretas. También proponemos la localización del sitio pac en dirección 3´ de la terminasa, entre orf32 y orf34 del genoma de MM1., This work was supported by grants from the Dirección General de Investigación Científica y Técnica (BCM2000-1002) and from Programa de Grupos Estratégicos de la Comunidad Autónoma de Madrid.

Paper based on the inaugural lecture of the 19th Congress of the Spanish Society for Microbiology., Infectious diseases currently kill more than 15 million people annually, and the WHO estimates that every year 1.6 million people die from pneumococcal diseases. Streptococcus pneumoniae (pneumococcus), a bacterium with a long biological pedigree, best illustrates the rapid evolution of antibiotic resistance, which has led to major public health concern. This article discusses the molecular basis of the two main virulence factors of pneumococcus, the capsule and cell-wall hydrolases, as well as new approaches to developing medicinal weapons for preventing pneumococcal infections. In addition, current knowledge regarding pneumococcal phages as potential contributors to virulence and the use of lytic enzymes encoded by these phages as therapeutic tools is reviewed., Las enfermedades infecciosas matan anualmente a unos 15 millones de personas y la OMS estima que 1,6 millones de esas muertes se deben a infecciones neumocócicas. Streptococcus pneumoniae (neumococo), una bacteria con una notable contribución histórica a la biología, es el mejor ejemplo que ilustra el rápido desarrollo de la resistencia a los antibióticos, lo que puede originar un grave problema sanitario. Esta revisión analiza las bases moleculares de los dos factores principales de virulencia en el neumococo, la cápsula y las hidrolasas de la pared celular y describe nuevos enfoques para el desarrollo de nuevas herramientas médicas para prevenir las infecciones neumocócicas. También se analizan el conocimiento actual de la posible contribución de los fagos de neumococo a la virulencia de esta bacteria y el uso como arma terapéutica de las enzimas líticas codificadas por estos fagos.

11 p.-6 fig.-1 tab., Two new temperate bacteriophages exhibiting a Myoviridae (phiB6) and a Siphoviridae (phiHER) morphology have been isolated from Streptococcus mitis strains B6 and HER 1055, respectively, and partially characterized. The lytic phage genes were overexpressed in Escherichia coli, and their encoded proteins were purified. The lytAHER and lytAB6 genes are very similar (87% identity) and appeared to belong to the group of the so-called typical LytA amidases (atypical LytA displays a characteristic two-amino-acid deletion signature). although they exhibited several differential biochemical properties with respect to the pneumococcal LytA, e.g., they were inhibited in vitro by sodium deoxycholate and showed a more acidic pH for optimal activity. However, and in sharp contrast with the pneumococcal LytA, a short dialysis of LytAHER or LytAB6 resulted in reversible deconversion to the low-activity state (E-form) of the fully active phage amidases (C-form). Comparison of the amino acid sequences of LytAHER and LytAB6 with that of the pneumococcal amidase suggested that Val317 might be responsible for at least some of the peculiar properties of S. mitis phage enzymes. Site-directed mutagenesis that changed Val317 in the pneumococcal LytA amidase to a Thr residue (characteristic of LytAB6 and LytAHER) produced a fully active pneumococcal enzyme that differs from the parental one only in that the mutant amidase can reversibly recover the low-activity E-form upon dialysis. This is the first report showing that a single amino acid residue is involved in the conversion process of the major S. pneumoniae autolysin. Our results also showed that some lysogenic S. mitis strains possess a lytA-like gene, something that was previously thought to be exclusive to Streptococcus pneumoniae. Moreover, the newly discovered phage lysins constitute a missing link between the typical and atypical pneumococcal amidases known previously., This work was supported by grants from the Dirección General de Investigación Científica y Técnica (BCM2003-00074) and from Redes Temáticas de Investigación Cooperativa (G03/103 and C03/14) (Ministerio de Sanidad y Consumo).

5 p.-1 fig.-2 tab., Scientific journals are periodical publications—until recently only in print—whose aim is to communicate and transmit scientific knowledge, especially advancements in the various fields of science. The community each journal addresses, and the thematic field covered, determine the publication’s characteristics. The earliest scientific journals covered general aspects of what is called science sensu strictu—mathematics and natural sciences. Throughout the nineteenth century, other journals appeared that covered the humanities, including philosophy,linguistics and sociology.